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This is a divisional of application Ser. No. 08/398,065 filed on Mar. 3, 1995, now U.S. Pat. No. 5,497,562.
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for the solid phase crystallization and polymerization of polymers. The invention relates more particularly to a unique system for heating the polymers in the solid state to achieve the desired reactions.
Prior art systems of the general type involve feeding of cold amorphous granular polymer material to a crystallizer and, after substantial heat input, discharging of hot crystallized product. A particular apparatus for achieving the crystallization may comprise an indirect heat supply unit or a fluid bed. The SOLIDAIRE® or TORUSDISC® equipment manufactured by Hosokawa Bepex Corporation of Minneapolis, Minn. are examples of indirect heat supply units which may be utilized for achieving the solid phase crystallization and/or polymerization. In such systems, steam or other heated fluid is passed through rotors and/or jackets which are in contact with the vigorously agitated granular polymer material. Due to the contact with these hot surfaces, the polymer is heated to the necessary temperature for achieving the crystallization and polymerization reactions.
In a fluid bed system, for example units manufactured by Hosokawa Bepex, heated air is brought into contact with the polymer material. In order to improve heat transfer and to achieve the temperatures required for the crystallization reaction, indirect heating elements in the form of tube bundles or plate coils may be immersed in the fluidized material.
Although processing of polymers in accordance with prior art systems can be successfully achieved, there have been persistent problems associated with stickiness of polymer chips which exhibit adhesive characteristics during the solid phase crystallization and polymerization. This has been a long-recognized difficulty as discussed in U.S. Pat. No. 3,014,011, and a proposed improvement has been discussed more recently in U.S. Pat. No. 5,090,134. In the latter case, the prevention of agglomeration and caking is specifically discussed.
SUMMARY OF THE INVENTION
The system of this invention comprises a process and apparatus uniquely suitable for achieving solid phase crystallization and polymerization of cold amorphous granular polymer, for example, the treatment of chips of polyethylene terephthalate. In the process of the invention, the chips are introduced to a crystallizer equipped with a source of infrared radiation. The chips are heated by means of the radiation, and the degree of heating is controlled to insure that the product is raised to a temperature sufficiently high to achieve crystallization and/or polymerization while not exceeding the melt temperature of the polymer.
A system of the type contemplated is especially suited for precise control by means of a microprocessor or computer. This is especially the case where the apparatus of the invention comprises a continuously operating unit with means for introducing the amorphous granular polymer through an inlet and means for discharging the crystallized polymer through an outlet spaced from the inlet. A plurality of spaced-apart sources of infrared radiation are associated with the unit and these sources can be individually controlled to provide optimum efficiency in the operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view, partly cut away, of a polymer processing unit characterized by the features of this invention;
FIG. 2 is an end elevational view of the unit shown in FIG. 1;
FIG. 3 is a vertical sectional view of an infrared radiation heater used in connection with the invention;
FIG. 4 is a perspective view of an alternative form of unit adapted to be employed in the practice of the invention; and,
FIG. 5 is a vertical, sectional view of the unit shown in FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
The drawings illustrate polymer processing units adapted for practicing the method of the invention. In FIGS. 1 and 2, the unit 10 consists of an elongated housing 12 having an inlet 14 for receiving cold amorphous granular polymer and an outlet 16 for discharge of crystallized polymer.
An agitator 18 is provided for rotation within the housing 12. This structure includes a plurality of paddles 20 which extend outwardly from the periphery of the agitator shaft 22. In accordance with known practice, the paddles are set at an angle whereby rotation of the agitator operates to continuously move polymer from the inlet end of the unit toward the outlet end. The residence time of the polymer is controlled by controlling the rotor speed and adjusting the paddle attitudes in accordance with known practice. The unit is also conventionally provided with gas transmission pipes 24 and 26 at its opposite ends so that heated air or the like may be introduced for movement within the housing cocurrently or countercurrently relative to the polymer movement.
The unit 10 is also provided with spaced-apart infrared radiant heaters 28. The particular heaters shown are of a type manufactured by Research Inc., Model 5208, however, it will be understood that various types of infrared radiant heaters could be utilized in the practice of the invention. It has been found that the infrared spectrum is well suited for thermoprocessing of polymer materials undergoing different morphological modifications in the course of crystallization and/or polymerization.
The heaters 28 shown each consist of a housing 30 having a clear quartz window 32 supported at its bottom side. Positioned above the window are a plurality of infrared radiant heat lamps 34. Passages 36 and 38 are provided for air and water cooling of the heaters. Gauge 40 is provided for monitoring the temperature conditions to insure proper heater operation. The interior surface 42 of the heater serves as a reflector whereby heat generated by the lamps 34 will pass through window 32.
In the practice of this invention, openings are defined in the top wall of housing 12, and a heater 28 is mounted over each opening so that the window of a heater is exposed within the housing. The polymer within the housing is, therefore, exposed to the heat generated by a heater.
FIG. 4 illustrates an alternative form of polymer processing unit which may be used in the practice of the invention. This apparatus 110 is of the general type described in U.S. Pat. No. 5,271,163, and includes an elongated housing 112. This housing defines an inner wall 114 and an outer wall 116 whereby passages 118 are defined between the vessel walls. Thus, the outer wall 116 constitutes a spaced-apart jacket for the inner wall 114.
Inlet fittings 120 are associated with the outer jacket whereby steam or other media may be introduced into the passages 118 defined between the inner and outer walls. Outlet fittings 122 are provided whereby condensate or other media may be removed and whereby constant circulation around the inner wall of the vessel can be achieved.
Material is introduced to the vessel 112 through inlet 126 and a material outlet 128 is provided at the opposite end of the vessel. If desired, heated gas may be introduced with the material for circulation through the vessel. Under such circumstances, the gas may be introduced through inlet 126 or a separate inlet 129, and a discharge pipe 130 for vapor discharge is provided. This arrangement will result in gases flowing across the vessel cocurrent with the material.
Alternatively, the pipe 130 may be employed for the introduction of gases which will move countercurrent to the material, and the separate pipe 129 may be employed for vapor discharge or this discharge may occur through inlet 126. This arrangement results in "countercurrent" flow.
An agitator consisting of tubular rotor 132 and rows of paddles 134 is mounted for rotation within the vessel 112, and motor 136 is employed for driving the rotor. As explained in the aforementioned patent, the paddles extend outwardly from the rotor surface which is adjacent the axis of rotation of the rotor. The paddles extend to a point closely adjacent the inner surface of inner wall 114 whereby the paddles will serve to propel material from the inlet of the vessel along the length of the vessel and to the outlet of the vessel.
A plurality of infrared radiant heaters 28 are associated with the housing 112. As described with reference to FIGS. 1-3, these heaters are used to supply the heat necessary for achieving recrystallization when polymer is processed in the apparatus.
FIG. 5 illustrates a particular paddle configuration shown in U.S. Pat. No. 5,271,163 and this is an example of a configuration particularly useful in a system which utilizes infrared radiation heating. As described in that patent, the rotor 132 supporting the paddles 148 and 180 defines an interior passage 138, and air is adapted to be delivered into this passage. The interiors of the paddles 180 define passages 184 communicating with passage 138, and the passages 184 open into the interior of vessel 112.
Gas is adapted to be delivered to the rotor 132 for passage outwardly through the nozzles 184. As shown in FIG. 4, the gas may comprise air supplied to the rotor through pipe 125 leading to rotary joint 127.
The system of the invention has certain distinct advantages over prior art arrangements. By relying primarily on radiant heating rather than on conductive or convective heating, dependence on an intervening medium such as heated air to achieve a desired temperature is avoided. Due to direct heat transfer to the particles by means of radiant energy, the polymer temperature can be maintained efficiently at an optimal level. The heat transfer rate with infrared radiation is much higher than with a convective system (such as a fluid bed), or a conductive system (such as when relying on SOLIDAIRE® and TORUSDISC® systems of the type manufactured by Hosokawa Bepex Corporation; general reference to such systems is found in copending application Ser. No. 08/272,027 entitled "Process and Apparatus for Solid Phase Polymerization of Polymers"). With such higher heat transfer rates, more thermoprocessing can be accomplished in less space.
The infrared radiant heaters have low thermal mass (inertia) and can, therefore, respond almost instantaneously to modulating controls. Accordingly, the temperature of the polymer can be maintained precisely. This control may focus on a given temperature range throughout the unit so that the output of thermocouples such as shown at 44 in FIG. 1, or other temperature sensing means, may be used by means such as microprocessor 46 to reduce or elevate the output of the radiant heaters to maintain that range. Alternatively, the unit may be divided into zones with specific temperature ranges assigned to each zone. As indicated, thermocouples 44 may be associated with the respective zones, and radiant heaters adjacent the respective zones may then be independently controlled.
The aforementioned heaters of the type manufactured by Research Inc. are an example of heaters which lend themselves to such controlled operation. Thus, process control instrumentation and SCR power controllers have been designed specifically for use with such heaters. Processing units 10 and 110 illustrated in this application are of a type which have been in the past implemented with temperature sensing means and, therefore, the systems of this invention are readily adapted to programmable computer controlled operation.
The adaptability to controlled operation is particularly important in connection with polymers which are highly sensitive and/or susceptible to sticking problems. In this regard, it is known that the melt temperature of a given polymer will vary depending on the degree of crystallization and/or polymerization that has taken place in the course of the processing.
With the system of this invention, the polymer temperature in any given zone of the unit can be maintained close to, but not exceeding, the polymer melt or sintering temperature. Accordingly, maximum efficiency can be achieved from the stand-point of crystallization and/or polymerization while avoiding the problems associated with overheating. It will be appreciated in this regard that the drawings illustrate two or three infrared radiant heaters in association with a processing unit, however, the number and location of these heaters may be varied as the processing applications vary.
The quick response control for infrared radiant heaters is also advantageous if emergency conditions are encountered. Thus, the unit temperature will drop very quickly if the heaters are shut down whereas the prior art systems described, because of the characteristic high thermal mass, are very slow to respond.
When considering the nature of individual polymer particles being processed, another advantage of the system of this invention becomes apparent. With convective or conductive heat transfer conditions, the polymer particles absorb heat energy dependent on their surface area which causes a substantial temperature gradient within each individual particle and reduces the overall reaction rate. At any given material temperature set point, the particle surface becomes "overheated" followed by softening of the particle surface layer and, as a result, undesirable agglomeration occurs. Therefore, the prior art systems described employ relatively low crystallization and/or polymerization temperatures thereby restricting the reaction rates.
On the contrary, the radiant heater system of the present invention is very efficient in terms of providing reduced temperature gradients in the polymer granules and improved reaction rates. This is due to the ability of radiant energy, particularly in the infrared portion of the electromagnetic spectrum, to penetrate quickly beneath the surface of the polymer particles.
This phenomenon is of special importance during the solid phase crystallization when semi-transparent amorphous chips have very favorable optical properties. Thus, with infrared radiant energy, the crystallization and morphological transition of the polymer can quickly begin at the center of the particle thereby reducing appreciably the risk of "overheating" the particle surface and thereby reducing or eliminating the tendency of the particles to stick together at an elevated temperature.
With the radiation technique of this invention, the rate of crystallization and/or polymerization is significantly improved, and an improvement in the quality of the end product is realized. These improvements are in the form of optimal crystal size, nucleation and crystallization.
The above-described advantages can be realized using the radiant heaters as the sole heat source, however, as indicated particularly by the description of the processing unit 110, various means may be employed to supplement the heat supply. These may comprise the provision of heated fluids in the surrounding jacket 114, 116, and/or within the rotor 132, and/or through the paddles 180.
The paddles 180, or other paddle means such as those of the type described in U.S. Pat. No. 5,271,163, may also be used for different purposes when employed in combination with the radiant heaters. Specifically, injection of air through rotor 132 and outwardly through paddles 180 will serve to increase the agitation of the polymer bed. This can result in greater uniformity in the reactions taking place.
It will be understood that various changes and modifications may be made in the invention as described without departing from the spirit thereof, particularly as defined in the following claims. | A system for the solid phase polymerization of polymers comprising a crystallizer, and wherein cold amorphous polymer is introduced to the crystallizer. A source of infrared radiation is associated with the crystallizer, and the polymer is heated by applying infrared radiation thereto. The degree of heating is controlled so that the polymer reaches the crystallization or polymerization temperature without exceeding the polymer melting point. | 5 |
BACKGROUND OF THE INVENTION AND PRIOR ART
This invention relates generally to cooking grills and specifically to so-called top side cooking grills that include an upper cooking head that is movably mounted between an upper, open position and a lower, cooking position in close proximity to a cooking surface.
Top side cookers have been in use for many years and have the advantage of accelerating the cooking of foodstuffs, such as hamburger, by applying heat and pressure to both sides thereof during the cooking process. The upper cooking head is relatively massive and accordingly has significant weight, which of course is required to apply pressure to the foodstuff The top side cooker manufactured by Keating of Chicago, Inc. has an upper head that is counterbalanced by a pair of gas springs, i.e., pistons that are under a constant pressure. Adjustment of the springs and the associated lifting mechanism to enable a smooth force transition from the upper position to the lower position of the cooking head is often difficult to accomplish, especially since the weight of the cooking head is required to apply pressure to the foodstuffs being cooked. In many instances, the cooking head must be prevented from forcefully impacting the grill surface when it is being lowered into the cooking position. When the mechanism is properly adjusted, the cooking head is free of the counterbalance force when it is very close to the cooking position. This enables the weight of the cooking head to apply pressure to the foodstuffs. Failure of the operator to control movement of the cooking head or failure of one of both of the gas springs could result in the cooking head closing with a substantial force and exposing the operator to potential injury as well as causing damage to the surface of the cooking gill.
The present invention solves the above problems of the prior art in a relatively simple and cost effective manner by providing a cushioning spring on the gas cylinder which prevents forceful engagement between the upper cooking head and the lower grill surface.
OBJECTS OF THE INVENTION
A principal object of the invention is to provide a novel top side cooker mechanism.
Another object of the invention is to provide a top side cooker mechanism that eliminates the possibility of accidental forceful contact between the upper cooking head and the grill surface.
A further object of the invention is to provide a top side cooker that is easier and safer to use.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention will be apparent upon reading the following description in conjunction with the drawings in which:
FIG. 1 is a partial simplified view of a top side cooker constructed in accordance with the invention;
FIG. 2 is a side view of the lift arm of the top side cooker of FIG. 1 that is partially cut away to reveal the gas cylinder and spring of the invention;
FIG. 3 is an end view of the structure of FIG. 2;
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 2; and
FIG. 5 illustrates the gas cylinder and spring of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawings, a top side cooker assembly 10 includes a body 12 having one or more legs 13 for supporting a cooking grill 14 that is heated by any suitable means (not shown). A movable upper cooking head 16 (also heated by well-known means, not shown) is suspended for arcuate movement between an upper, open position and a lower, cooking position in which cooking surface 18 of cooking head 16 is positioned close to cooking grill 14. Cooking head 16 is manually movable in an arcuate path between the two positions in response to an operator raising and lowering a handle 20 that is connected to a supporting arm 24 positioned over cooking head 16. In the construction of the Keating of Chicago top side cooker, cooking head 16 is pivotally connected at the rear to a pivot structure 26 and to a lift arm 30 and includes a pair of simultaneously adjustable height adjusters 22 and 34 at the front and rear of the cooking head for changing the space between cooking surface 18 and grill 14. Cooking head 16 is supported for limited vertical movement with respect to arm 24 by a pin and slot arrangement 17. Thus, the cooking head is suspended in a "semi-floating" manner. The pivotal connection at the rear of cooking head 16 to lift arm 30 is indicated at 26.
As best seen in FIGS. 3 and 4, lift arm 30 is "L" shaped and has a "T" shaped cross section. A generally U-shaped frame 38 is secured to the rear 36 of body 12 and, by virtue of its inwardly directed flanged edges 39, confines a smaller U-shaped slide unit 40 to longitudinal movement therein. Frame 38 may be secured to housing 12 by any suitable means, including the flanges 37 that are illustrated. The lower end of lift arm 30 is pivotally connected to the lower end of slide unit 40 and also to the lower ends of a pair of gas cylinder/spring devices 42 and 44 by a pin 41. The upper ends of the gas cylinder/spring devices are pivotally connected to the sides of frame 38. Thus it should be apparent that as handle 20 is moved upwards, cooking head 16 is moved in an arcuate manner between its lower, cooking position and its upper, open position. Lift arm 30 is moved both horizontally and vertically downward (as indicated by the arrows adjacent handle 20 and lift arm 30) and conveys a counterbalancing force to offset the weight of the cooking head. Its vertical movement is enabled by slide 40 that moves, in a confined manner, within frame 38, with gas cylinders 42 and 44 providing the counterbalancing force. A plate 30a is affixed to the lower end of lift arm 30 and a screw and lock nut arrangement 30b cooperates with a stop 30c on the rear 36 of body 12 to limit the downward travel of lift arm 30 and hence defines the upper position of cooking head 16. It will be appreciated that stop 30c may also conveniently be made a part of frame 38.
In accordance with the present invention, the gas cylinders include springs 46 and 48 that exert a residual positive supporting force when cooking head 16 approaches the cooking (lowered) position. As seen in FIG. 5, spring 48 encircles the rod 50 of cylinder 44 and is compressed between the body of the cylinder and a washer 49 that abuts end piece 47. The cylinder/spring arrangement may be manufactured by cutting the rod of the cylinder and rewelding after the spring and washer have been positioned thereover. The effect is that a residual force is always present to cushion the movement of the cooking head as it approaches the cooking position despite failure of the operator to control the cooking head movement or "bottoming out" of one or both of the gas springs. Those skilled in the art will appreciate that the cooking head may weigh on the order of 100 pounds and therefore, even a slight misadjustment of the top side cooker mechanism or diminished performance of the gas springs can have sometimes serious consequences.
Thus, with the invention, the problem of the cooking head inadvertently crashing into the grill surface with consequent damage thereto and the possibility of such occurrence causing injury to an operator due to grease spattering or the like is obviated.
What has been described is a novel gas cylinder/spring arrangement for a top side cooker that obviates the problem of the upper cooking head crashing into the grill surface and potentially damaging the grill or causing injury to an operator. It is recognized that numerous changes to the described embodiment of the invention will occur to those skilled in the art without departing from its true spirit and scope. The invention is to be limited only as defined in the claims. | A top side cooker includes a cooking head that is counterbalanced by a pair of gas cylinders. A lift arm couples the gas cylinders to the cooking head. A compression spring is fitted on the rod of each gas cylinder to provide a positive force at the end of the rod travel for precluding the heavy cooking head from crashing into the grill surface. | 0 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to apparatus and methods for managing air flow during the manufacture of nonwoven webs and laminates.
BACKGROUND OF THE INVENTION
[0002] Meltblowing and spunbond processes are commonly employed to manufacture nonwoven webs and laminates. With meltblowing, a molten thermoplastic is extruded from a die tip to form a row of filaments or fibers. Converging sheets or jets of hot air impinge upon the fibers as they are extruded from the die tip to stretch or draw the fibers, thereby reducing the diameter of the fibers. The fibers are then deposited in a random manner onto a moving collector belt to form a nonwoven web.
[0003] With spunbond processes, continuous fibers are extruded through a spinneret. Air is directed at the extruded fibers to separate and orient them. The fibers are collected onto a moving collector belt. At a downstream location, the fibers are consolidated by passing the layer of fibers through compacting roller, for instance. The spunbond process frequently utilizes quenching air to cool the extruded before they contact the collector belt.
[0004] Large volumes of air are used during both the meltblown and spunbond process. Moreover, much of the air is heated and moving at very high velocities, sometimes approaching the speed of sound. Without properly collecting and disposing of the process air, the air would likely disturb personnel working around the manufacturing apparatus and other nearby equipment. Further, the heated air would likely heat the surrounding area in which the nonwoven is being produced. Consequently, attention must be paid to collecting and disposing of this process air.
[0005] Managing the process air is also important to producing a homogeneous nonwoven web across the width of the web. The homogeniety of the final nonwoven web depends greatly on the air flow around the fibers as they are deposited onto the collector belt. For instance, if the air flow velocity is not uniform in the cross-machine direction, the fibers will not be deposited onto the collector belt uniformly, yielding a non-homogeneous nonwoven web.
[0006] Various air management systems have been used to collect and dispose of the process air. One particular air management system uses a collecting duct situated below a perforated collector belt to collect and dispose of the process air. An air moving device, such as a fan or vacuum pump, is connected to the collecting duct to actively draw the air into the collecting duct. The collecting duct is comprised of a plurality of a smaller air passageways arranged side-by-side in a rectangular grid. The grid includes a central row of air passageways extending across the machine width and upstream and downstream air passageways flanking either side of the central row. The central row of air passageways is disposed directly below the extrusion die in what is commonly referred to as the forming zone. Each air passageway includes an inlet and an outlet with a 90 degree elbow in between. An air moving device is operatively connected to each outlet to draw the process air into the individual inlets.
[0007] As mentioned above, the air flow velocity of the process air around the collector belt should be uniform, especially in the machine direction at the forming zone, to form a homogeneous nonwoven web. Achieving a uniform air flow velocity, however, has proven challenging. In the collecting duct described above, moveable dampers are associated with each outlet of the air passageways. To achieve uniform air flow velocity with this collecting duct, an technician must manually manipulate each damper until the air flow velocity is sufficiently uniform. In some instances, the technician may be unable to achieve a uniform air flow velocity no matter how much time and effort is spent adjusting the dampers. Moreover, the dampers must be readjusted each time a different fiber material or process air flow rate is used. Thus, the operator must readjust the dampers virtually every time the process is started or an operating condition is changed. The readjustment process takes a great deal of time and may ultimately yield a nonuniform air flow velocity regardless of how the moveable dampers are adjusted.
[0008] What is needed, therefore, is an air management system that can collect and dispose of the process air so as to produce a uniform air flow velocity at the collector belt, especially around the forming zone. The air management system should be designed such that dampers and other manual controls are not necessary, even over a wide range of process air flow rates.
SUMMARY OF INVENTION
[0009] The present invention provides a melt spinning system and, more particularly, a melt spinning and air management system that overcomes the drawbacks and disadvantages of prior air management systems. The air management system of the invention includes at least one air handler for collecting air discharged from a melt spinning apparatus. In accordance with a general objective of the invention, the air handler produces a uniform air flow velocity in at least the cross-machine direction as the air enters the air handler. This is accomplished without the typical adjustable baffles and dampers required in the past. The air handler generally includes an outer housing having walls defining a first interior space. One of the walls has an intake opening for receiving the discharge air from the melt spinning apparatus. Another wall has an exhaust opening for discharging the air collected by the air handler. The intake opening is in fluid communication with the first interior space. An inner housing is positioned within the first interior space and has walls defining a second interior space. At least one of the walls of the inner housing has an opening. The first interior space communicates with the second interior space through the opening. The second interior space is in fluid communication with the exhaust opening.
[0010] In one aspect of the invention, the opening between the first interior space and the second interior space is an elongate slot and preferably includes a center portion having a wider dimension than the end portions thereof. The intake opening is positioned at the top of the outer housing, and the slot in the inner housing is disposed proximate to the bottom of the outer housing. The outer housing can further include a filter member for filtering particulates from the air discharged by the melt spinning apparatus.
[0011] The invention further provides an air management system including three air handlers. One air handler is positioned directly below the melt spinning apparatus in a forming zone. Another air handler is positioned upstream of the forming zone, and the other air handler is positioned downstream of the forming zone. The widths of the intake opening of the upstream and downstream air handlers in the machine direction are respectively greater than the width of the intake opening of the air handler positioned below the forming zone. The upstream and downstream air handlers collect air which spills over, i.e., not collected, from the air handler below the forming zone.
[0012] Various additional advantages and features of the invention will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description taken in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF DRAWINGS
[0013] [0013]FIG. 1 is a schematic plan view of a two-station production line incorporating the air management system of the invention;
[0014] [0014]FIG. 2 is a perspective view of the two-station production line of FIG. 1 with the collector belt removed for clarity;
[0015] [0015]FIG. 3 is a perspective view of the air management system of FIG. 1;
[0016] [0016]FIG. 4 is a partially disassembled perspective view of the forming zone air handler of FIG. 3;
[0017] [0017]FIG. 5 is a cross sectional view of the forming zone air handler in FIG. 4 taken along lines 5 - 5 ;
[0018] [0018]FIG. 6 is a plan view of the forming zone air handler bottom in FIG. 4 taken along lines 6 - 6 ;
[0019] [0019]FIG. 7 is a partially disassembled perspective view of one of the spillover air handlers of FIG. 3;
[0020] [0020]FIG. 8 is a perspective view of another embodiment of the air management system of the invention; and
[0021] [0021]FIG. 9 is cross sectional perspective view of the air management system in FIG. 8 taken along lines 9 - 9 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] With reference to FIG. 1, a two-station production line 10 is schematically illustrated. The production line 10 incorporates an air management system 12 of the invention at both an upstream station 14 and a downstream station 16 . While the air management system 12 has been illustrated in conjunction with the two-station production line 10 , the air management system 12 is generally applicable to other production lines having a single station or a plurality of stations. In a single station production line, the nonwoven web can be manufactured using any one of a number of process, such as a meltblowing process or a spunbond process. In a multiple-station production line, a plurality of nonwoven webs can be manufactured to form a multiply laminate. Any combination of meltblowing and spunbonding processes may be used to manufacture the laminate. For instance, the laminate may include only nonwoven meltblown webs or only nonwoven spunbond webs. However, the laminate may include any combination of meltblown webs and spunbond webs.
[0023] The two-station production line 10 in FIG. 1 is shown forming a two-ply laminate 18 with a meltblown layer or web 20 on the bottom and a spunbond layer or web 22 on the top. The two-ply laminate 18 is consolidated downstream using compacting rolls, for example. The upstream station 14 includes a melt spinning assembly 24 with a meltblowing die 26 and the downstream station 16 includes a melt spinning assembly 28 with a spunbond die 30 .
[0024] To form the meltblown web 20 , the meltblowing die 26 extrudes a plurality of thermoplastic filaments or fibers 32 onto a collector such as a belt 34 . It will be appreciated that the collector 34 may be any other substrate, such as a substrate used as a component in the manufacture of a product. Converging sheets or jets of hot air, indicated by arrows 36 , from the meltblowing die 26 impinge upon the fibers 32 as they are extruded to stretch or draw the fibers 32 . The fibers 32 are then deposited in a random manner onto the collector moving belt 34 from right to left to form the meltblown web 20 . The collector belt 34 is perforated to permit the air to flow through the collector belt 34 and into the air management system 12 .
[0025] Similarly, to form the spunbond web 22 , the spunbond die 30 extrudes a plurality of thermoplastic filaments or fibers 38 onto the meltblown web 20 being transported by the moving collector belt 34 . Hot air, indicated by arrows 40 , from the spunbond die 30 impinges upon the fibers 38 to impart rotation to the fibers 38 . Additionally, air ducts 42 direct quenching air onto the extruded fibers 38 to cool the fibers 38 before they reach the meltblown web 20 . As with the upstream station 14 , the air at downstream station 16 passes through the nonwoven web 20 and the collector belt 34 and into the air management system 12 .
[0026] Several cubic feet of air per minute per inch of die length flow through each station 14 , 16 during the manufacture of the melblown and spunbond webs 20 , 22 . The air management system 12 of the invention efficiency collects and disposes of the air from through the stations 14 , 16 . More importantly and as will be discussed in greater detail below, the air management system 12 collects the air such that the air has a substantially uniform flow velocity at least in the cross-machine direction as the air passes through the collector belt 34 . Ideally, the fibers 32 , 38 are deposited on the collector belt 34 in a random fashion to form the metlblown and spunbond webs 20 , 22 which are homogeneous. If the air flow velocity through the collector belt 34 is nonuniform, the resultant web will likely not be homogeneous.
[0027] With reference to FIG. 2, transport structure 50 of the two-station production line 10 of FIG. 1 is shown. While the two-station production line 10 includes two air management systems 12 , the following description will focus on the air management system 12 associated with the upstream station 14 . Nevertheless, the description will be equally applicable to the air management system associated with downstream station 16 .
[0028] With further reference to FIGS. 2 and 3, air management system 12 includes three discrete air handlers 52 , 54 , 56 disposed directly below the collector belt 34 . Air handlers 52 , 54 , 56 include intake openings 58 , 60 , 62 and oppositely disposed exhaust openings 64 , 66 , 68 .
[0029] Individual exhaust conduits 70 , 72 , 74 are connected respectively to exhaust openings 64 , 66 , 68 . With specific reference to FIG. 3, exhaust conduit 70 , which is representative of exhaust conduits 72 , 74 , is comprised of a series of individual components: first elbows 76 , second elbows 78 , elongated portion 80 , down portion 82 , and third elbow 84 . A series of parallel guide vanes 86 extend through down portion 82 and third elbow 84 . In operation, a variable speed fan (not shown) or any other suitable air moving device is connected to third elbow 84 to draw the air through the air management system 12 .
[0030] With continued reference to FIGS. 2 and 3, air handler 54 is located directly below the forming zone, i.e., the location where the fibers contact the collector belt 34 . As such, air handler 54 collects and disposes of the largest portion of air used during the extrusion process. Upstream air handler 56 and downstream air handler 52 collect spill over air which air handle 54 does not collect.
[0031] With reference now to FIGS. 4 - 6 , forming zone air handler 54 includes an outer housing 94 which includes intake opening 60 and oppositely disposed exhaust openings 66 . Intake opening 60 includes a perforated cover 96 with a series of apertures through which the air flows.
[0032] Depending of the manufacturing parameters, air handler 54 may be operated without using the perforated cover 96 at all. Air handler 54 further includes an inner housing or box 98 which is suspended from the outer housing 94 by means of spacing members 100 which include a plurality of openings 101 therein. Two filter members 102 , 104 are selectively removable from air handler 54 so that they may be periodically cleaned. The filter members 102 , 104 slide along stationary rail members 106 , 108 . Each of these filter members 102 , 104 are perforated with a series of apertures through which the air flows.
[0033] The inner box 98 has a bottom panel 110 that includes an opening such as slot 112 with ends 114 , 116 and a center portion 118 . As illustrated in FIG. 6, slot 112 extends substantially across the width, i.e., the cross-machine direction, of the inner box 98 . The slot 112 is narrow at ends 114 , 116 and widens at center portion 118 . The slot 112 could be formed from one or more openings of various shapes, such round, elongate, rectangular, etc.
[0034] The shape of slot 112 influences the air flow velocity in the cross machine direction at the intake opening 56 . If the shape of the slot 112 is not properly contoured the air flow velocities at the intake opening 56 may vary greatly in the cross machine direction. The particular shape shown in FIG. 6 was determined through an iterative process using a computational fluid dynamics (CFD) model which incorporated the geometry of the air handler 54 . A series of slot shapes were evaluated at intake air flow velocities ranging between 500 to 2500 feet per minute. After the CFD model analyzed a particular slot shape, the air flow velocity profile in the cross machine direction was checked. Ultimately, the goal was to choose a shape for the slot 112 which provided a substantially uniform air flow velocity in the cross machine direction at intake opening 56 . Initially, a rectangular slot 112 was evaluated, yielding air flow velocities in the cross machine direction at the intake opening 56 which varied by as much as twenty percent. With the rectangular slot 112 , the air flow velocities near the ends of the intake opening 56 were greater than the air flow velocities approaching the center of the intake opening 56 . To address this uneven air flow velocity profile, the width of ends 114 , 116 was reduced relative to the width of the center portion 118 . After approximately five iterations, the shape of slot 118 is FIG. 6 was chosen. That slot shape yields air flow velocities in the cross machine direction at the intake opening 56 which varied by ±0.5%.
[0035] With specific reference to FIG. 5, air enters through perforated cover 96 and passes through perforated filter members 102 , 104 as illustrated by arrows 120 . The air passes through the gap between the inner box 98 and the outer housing 94 as illustrated by arrows 122 . The air then enters the interior of inner box 98 through slot 112 as illustrated by arrows 124 . Finally, the air exits the inner box 98 through exhaust opening 66 as illustrated by arrows 126 and then travels through exhaust conduit 72 . The openings 101 in spacing members 100 allow the air to move in the cross-machine direction to minimize transverse pressure gradients.
[0036] Generally, air handlers 52 , 56 have a similar construction and air flow path as air handler 54 . However, as FIG. 3 illustrates, air handlers 52 , 56 have much wider, i.e, in the machine direction, intake openings 58 , 62 than intake opening 60 of air handler 54 . The width of the these intake openings 58 , 62 may vary depending on the particular manufacturing parameters. The following discussion of air handler 52 is equally applicable to air handler 56 . Thus, with specific reference to FIG. 7, air handler 52 includes an outer housing 136 which includes intake opening 58 and exhaust openings 64 . Intake opening 60 includes a perforated cover 137 with a series of apertures through which the air flows. Depending on the manufacturing parameters, air handler 52 may be operated without using perforated cover 137 at all. Air handler 52 further includes an inner housing or box 138 which is suspended from the outer housing 136 by means of spacing members 140 which include a plurality of openings 142 therein. Unlike air handler 54 , air handlers 52 , 56 do not include filter members 102 , 104 .
[0037] The inner box 138 includes a bottom panel 144 with a slot 146 which is configured similarly to slot 112 . Slot 146 includes ends 148 , 150 and center portion 152 . Like slot 112 , the width at center portion 152 is greater than the width at ends 148 , 150 .
[0038] As mentioned above, the air flow path through air handler 52 is similar to the air flow path in air handler 54 . Specifically, air enters through perforated cover 137 as illustrated by arrows 154 and passes through the gap between the inner box 138 and the outer housing 136 as illustrated by arrows 156 . The air then enters the interior of inner box 138 through slot 146 as illustrated by arrow 158 . Finally, the air exits the inner box 138 through exhaust opening 64 as illustrated by arrow 160 and then travels through exhaust conduit 70 . The openings 142 in spacing members 140 allow the air to move in the cross-machine direction to minimize transverse pressure gradients.
[0039] Another embodiment of the air management system of the invention is shown generally as 170 in FIGS. 8 and 9. As described above, air management system 12 includes three separate and discrete air handlers 52 , 54 , 56 . In contrast, air management system 170 includes air handlers 172 , 174 , 176 which share common walls to form a unitary device. Air handler 174 is placed under the forming zone of the production line to collect the majority of the process air and air handlers 172 , 176 collect spill over air which air handler 174 does not collect. Each air handler 172 , 174 , 176 includes an intake opening 178 , 180 , 182 over which a single perforated cover 184 is placed. A plurality of individual perforated covers may be used in place of the single perforated cover 184 . Each air handler 172 , 174 , 176 further includes exhaust openings 186 , 188 , 190 oppositely disposed on either end of the respective air handlers 172 , 174 , 176 . Separate exhaust conduits (not shown) similar to exhaust conduits 70 , 72 , 74 connect to exhaust openings 186 , 188 , 190 to pull the air out of the air handlers 172 , 174 , 176 . Air handler 174 may include a filter member having a perforated surface through which the incoming air flows.
[0040] Air handlers 172 , 174 , 176 include inner boxes 192 , 194 , 196 and sidewalls 198 , 200 , 202 , 204 . Spacing members 206 , 208 , 210 hold inner boxes 192 , 194 , 196 away from sidewalls 198 , 200 , 202 , 204 . Inner boxes 192 , 194 , 196 include bottom panels 212 , 214 , 216 having slots 218 , 220 , 222 . The air flow path through air handlers 172 , 174 , 176 is similar to the air flow path in air handlers 52 , 54 , 56 . The air flow path through air handler 74 is represented by arrows 224 .
[0041] While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in considerable detail in order to describe the best mode of practicing the invention, it is not the intention of applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the spirit and scope of the invention will readily appear to those skilled in the art. The invention itself should only be defined by the appended claims, wherein we claim: | An air handler for collecting air discharged from a melt spinning apparatus. The air handler includes an outer housing having walls defining a first interior space. One of the walls has an intake opening for receiving the discharge air. Another wall has an exhaust opening for discharging the air. The intake opening is in fluid communication with the first interior space. An inner housing is positioned within the first interior space and has walls defining a second interior space. At least one of the walls of the inner housing has an opening. The first interior space communicates with the second interior space through the opening. The second interior space is in fluid communication with the exhaust opening. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a drilling rig comprising a mast, a drilling drive mounted for displacement thereon, and a drilling element, which can be rotatably driven and moved along the mast by the drilling drive system, the drilling element comprising a continuous screw auger disposed below the drilling drive system and an extension which is connected to the continuous screw auger and which extends upwardly through the drilling drive.
The invention further relates to a drilling method, in which a drilling element is rotatably driven and moved along a mast by means of a drilling drive, the drilling element comprising a continuous screw auger disposed below the drilling drive and an extension which is connected to the continuous screw auger and which extends upwardly through the drilling drive.
2. Description of Related Art Including Information Disclosed Under 37 CFR §§1.97 and 1.98
The use of so-called continuous screw augers for creating bore holes and, in particular, for creating foundation elements has been known for many years. In a continuous screw auger, a drill helix is disposed along the entire length of the drilling bar for the purpose of conveying loosened earth material out of the bore hole toward the surface by means of rotary motion. A continuous screw auger is driven by means of a drilling drive system, by means of which the continuous screw auger is also moved in the boring direction along a usually vertically positioned mast. In this known method, the depth of the bore hole is restricted by the length of the continuous screw auger and the height of the mast.
In order to increase the depth of the bore hole beyond the length of the mast or the length of the continuous screw auger, DE 601 02 255 T2or EP 1 614 853 B1 proposes that an extension bar be disposed at the top of the continuous screw auger, which extension bar extends upwardly through the drilling drive system. The depth of the bore hole can thus be increased by approximately the length of the extension bar.
However, feed helixes cannot be mounted on the extension bar for functional reasons. When sinking a bore hole beyond the length of the continuous screw auger, the earth material excavated can thus no longer be conveyed by the feed helixes up to the surface. This earth material thus accumulates in the bore hole above the continuous screw auger in the region of the extension bar. This can lead to undesirable earth compaction or choking of the bore hole, which makes it difficult to subsequently withdraw the drilling element from the bore hole. Furthermore, the wall of the bore hole can be damaged in this region, which can adversely affect the installation of a foundation element in the bore hole by filling the same with filling material. In order to prevent this, the drilling element must be intermittently removed from the bore hole to remove the earth material. This is time-consuming.
BRIEF SUMMARY OF THE INVENTION
The object underlying the present invention is to provide a drilling rig and a drilling method, by means of which bore holes can also be efficiently created with the aid of continuous screw augers beyond the length of the latter, whilst ensuring good quality of the bore holes.
This object is achieved according to the invention with a drilling rig having a mast, a drilling drive displaceably mounted thereon and a drilling element which can be rotatably driven and moved along the mast by said drilling drive, which drilling element has a continuous screw auger disposed below the drilling drive and an extension which is connected to said continuous screw auger and extends upwardly through the drilling drive, wherein a displacement head is disposed between said continuous screw auger and said extension; and by a drilling method in which in a first drilling step, the drilling element is rotated and displaced along the mast by means of the drilling drive to sink a bore hole to the first drilling depth, wherein the first drilling depth is approximately equal to the length of said continuous screw auger and at which depth the drilling drive has reached its lower end position at the bottom end of the mast, a material-transporting step is carried out concurrently with the first drilling step, during which earth material is transported by said continuous screw auger from the upper part of the bore hole to the surface, and in a second drilling step starting from said first drilling depth, the drilling element is rotated and displaced along the mast by means of the drilling drive to sink the bore hole to the second drilling depth and earth material is forced into a wall of the upper part of the bore hole by feeding the earth material transported by said feed helix from the lower part of the bore hole to said displacement head.
The drilling rig of the invention is characterized in that a displacement head is disposed between the continuous screw auger and the extension.
When sinking a bore hole beyond the length of the continuous screw auger, the displacement head forces the earth material being conveyed toward the top aside into the wall of the bore hole directly above the continuous screw auger. Thus earth material can no longer accumulate inside the bore hole and therefore lead to choking. Rather, the displacement head forces the earth material aside and in doing so serves to positively compact and additionally stabilize the wall of the bore hole. This improves the stability and quality of the bore hole and actively prevents the bore hole from caving in. In this way, the drilling rig of the invention can be used to sink the bore hole beyond the length of the continuous screw auger in a single continuous operation until the end of the extension has been reached. This considerably accelerates the creation of a bore hole of increased depth and additionally reduces the quantity of excavated material to be hauled away.
In principle, the extension can have any form. In particular, the extension can be a telescope bar or a bar composed of several segments. It is particularly preferred, according to the invention, for the extension bar to be designed as a Kelly bar having drive ridges on its outside surface. The drive ridges on the outsides surface of the normally single-piece bar operatively interact with corresponding entrainers of an output device of the drilling drive system in order to transmit a torque from the drilling drive system to the extension. The drive ridges are disposed parallel to the drilling axis so that the former permit axial displacement of the extension through the annular drilling drive system. So-called locking recesses having transversely directed ridge sections can be further provided for transferring axial forces from the drilling drive system to the extension.
For achieving particularly large drilling depths it is advantageous, according to the invention, when the length of the continuous screw auger is approximately equal to that of the mast or to a maximum movement distance of the drilling drive. The maximum movement distance of the drilling drive, which is displaceable along the mast, can be utilized in this way. A bore hole, the depth of which corresponds to the length of the continuous screw auger, can thus be created efficiently.
For installing a foundation element it is advantageous, according to the invention, when the continuous screw auger and/or the extension comprises a hollow core tube. The hollow core tube thus allows for feeding in a filling material, particularly a solidifying or settable suspension such as concrete, for example, directly through the drilling element after sinking the bore hole. For this purpose, one or more discharge orifices are provided at the bottom end of the continuous screw auger. The bore hole can thus be filled concurrently from the bottom up while withdrawing the continuous screw auger from the bore hole.
A wide variety of displacement heads can be used on the drilling element of the invention. It is thus possible to use, between the extension and the continuous screw auger, axially symmetrical displacement heads, displacement heads that are eccentric relative to the drilling axis or other displacement heads.
It is particularly preferred, according to the invention, when the displacement head comprises a cylindrical displacement section, the diameter of which is approximately equal to the drilling diameter. The drilling diameter is predetermined by the outside diameter of the drill helixes on the continuous screw auger or by corresponding radial cutting edges at the bottom end of the continuous screw auger. The displacement section can be slightly smaller or larger than this drill diameter, depending on the earth properties. An equally dimensioned diameter is advantageous, since it facilitates both the insertion of the displacement head into the bore hole and the withdrawal of the continuous screw auger from the bore hole.
According to the invention, it is advantageous when the displacement head comprises a lower conical section, the diameter of which increases from the diameter of a central tube in the continuous screw auger upwardly to the diameter of the displacement section. Thus, the earth material conveyed up to the displacement head can be gradually forced into the wall of the bore hole. This also facilitates the insertion of the displacement head into the bore hole.
The insertion of the displacement head into the bore hole is further improved, according to the invention, by providing said lower conical section with a lower helix, which can convey earth material upwardly to the displacement section during the drilling operation. This lower helix is thus situated on the conical outside surface of the displacement section and has the same conveying direction as that of the feed helix of the continuous screw auger.
Furthermore, it is advantageous, according to the invention, when the displacement head comprises an upper conical section, the diameter of which tapers from the diameter of the displacement section upwardly to the diameter of the extension. This arrangement allows for material falling onto the displacement head from above to enter the displacement zone of the displacement section.
This effect is assisted, according to the invention, by providing an upper helix, capable of conveying earth material downwardly to the displacement section during the drilling operation, on the upper conical section. This helix thus has a reversed pitch direction compared with the helixes of the continuous screw auger or the helix provided on the lower conical section. The upper helix actively conveys earth material falling from above into the zone of the displacement section.
In a preferred embodiment of the invention, the displacement section and/or at least one of the conical sections thereof is further provided with displacement elements. The displacement elements can be welded-on strips or arcuate segment-shaped elements, which improve the action of forcing or incorporating earth material into the wall of the bore hole. At the same time, the displacement elements can serve as wear parts that can be easily replaced when subjected to heavy-duty earth removal.
The drilling method of the invention is characterized in that in a first drilling step continuing to a first drilling depth equal to the length of the continuous screw auger, earth material is conveyed to the surface by the continuous screw auger, and that in a second drilling step starting from the first drilling depth, the drilled material is fed by the continuous screw auger to the displacement head, by means of which the earth material is forced into the wall of a bore hole.
The advantages described above with respect to the sinking of the bore hole beyond the length of the continuous screw auger, stabilizing the wall of the bore hole and preventing the accumulation of excavated material are achieved when using this method of the invention. This drilling method makes it possible to create the bore hole in a single continuous operation or intermittently in a number of steps, the drilling element being withdrawn at definite time intervals or at certain depths. Particularly effective stabilization of the wall of the bore hole can thus be achieved by virtue of the fact that the displacement head travels past the wall of the bore hole several times.
For creation of a foundation element, it is preferred, according to the invention, that the filling material used to form the foundation element is introduced into the bore hole when the final depth has been reached. The filling material can be a dry material, for example, sand, lime, or the like or a settable suspension such as a concrete mix. The filling material is preferably introduced into the bore hole through a central core tube in the continuous screw auger.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention is further explained below with reference to preferred exemplary embodiments illustrated diagrammatically in the attached drawings, in which:
FIG. 1 is a diagrammatic side view of a drilling rig of the invention at the commencement of the drilling method of the invention;
FIG. 2 is a diagrammatic side view of the drilling rig shown in FIG. 1 on conclusion of the first drilling step;
FIG. 3 is a diagrammatic lateral view of the rig shown in FIG. 1 and FIG. 2 in the second drilling step;
FIG. 4 is a diagrammatic partial view of the drilling rig of the invention during the first drilling step; and
FIG. 5 is a diagrammatic partial view of the drilling rig of the invention during the second drilling step.
DETAILED DESCRIPTION OF THE INVENTION
A drilling method of the invention together with a drilling rig 10 of the invention is illustrated in FIGS. 1 to 3 . As shown in FIG. 1 , the drilling rig 10 comprises an approximately vertically aligned mast 12 , which is pivotally mounted via an adjusting mechanism 13 on a base 14 . The base 14 is in the present exemplary embodiment in the form of a crawler type vehicle having a rotatable superstructure.
A slide 18 is mounted in known manner for displacement along the mast 12 via a cable pulley mechanism. An annular drilling drive 16 is provided on the slide 18 for the purpose of driving the bar-shaped drilling element 20 . The lower region of the drilling element 20 comprises a so-called continuous screw auger 22 , which is composed of a mid-conduit or core tube 24 , on the outside surface of which a feed helix 26 extends over virtually the entire length thereof. A cutting unit 28 for removing the earth material is formed in known manner on the bottom end of the continuous screw auger 22 .
The length of the continuous screw auger 22 is adjusted to that of the mast 12 and is approximately equal to the length of the mast 12 . In the exemplary embodiment illustrated, the mast has a length of about 20 m, while the length of the continuous screw auger is about 15 m. The length of the continuous screw auger 22 is somewhat shorter than the length of the mast 12 , this being substantially due to the size and length of the drilling drive 16 , including the slide 18 .
A displacement head 40 , which will be described below in more detail with reference to FIGS. 4 and 5 , is connected to the top end of the continuous screw auger 22 below the drilling drive 16 . Adjoining the displacement head 40 , a bar-shaped extension 30 is attached, which extends upwardly through the annular drilling drive 16 from the displacement head 40 disposed below the drilling drive system 16 . Drive ridges 32 extending longitudinally in the drilling direction are disposed on the outside surface of the extension 30 as in a Kelly bar. The torque of the drilling drive system 16 can be transmitted by way of these drive ridges 32 to the extension 30 and thus to the drilling element 20 as a whole. The drive ridges 32 further permit, in known manner, axial displacement of the extension 30 in relation to the drilling drive 16 with concurrent torque transmission.
In a first drilling step illustrated in FIG. 2 , a bore hole 6 is sunk until the top end of the continuous screw auger 22 is reached. During this first drilling step, earth material removed by the cutting unit 28 is conveyed by the feed helixes 26 upwardly out of the bore hole 6 . On conclusion of the first drilling step, the drilling drive 16 is moved until it reaches its maximum movement distance, that is to say, from its upper initial position shown in FIG. 1 to its lower end position at the bottom end of the mast. In order to sink the bore hole 6 further, the drilling element 20 is moved further down by way of the extension 30 with the drilling drive 16 now stationary. The downward advance of the drilling rig in the drilling direction can significantly be brought about substantially by the weight of the drilling element 20 and the propelling action of the feed helixes 26 . However, the drilling drive 16 can alternatively be reset and the extension 30 can be actively moved in the drilling direction.
In this second drilling step, the removed earth material can no longer be conveyed by the feed helixes 26 of the continuous screw auger 22 toward the surface. In order to prevent choking in the region of the bar-shaped extension 30 , which has now entered the bore hole 6 , the displacement head 40 forces this removed earth material, aside into the wall of the bore hole as proposed by the invention. On conclusion of the second drilling step, in which the bar-shaped extension is moved into its bottom end position as shown in FIG. 3 , filling material can be fed into the bore hole 6 at the bottom end of the continuous screw auger 22 from a suspension port 34 at the top end of the extension 30 via the inner cavity of the extension 30 and the core tube 24 .
FIG. 4 illustrates the drilling method of the invention during the first drilling step. Here, a bore hole 6 is formed in the ground 2 by the continuous screw auger 22 . Feed helixes 26 convey the removed earth material 4 upwardly out of the bore hole 6 toward a surface 3 . The excavated earth material 4 can be removed from here and hauled away in known manner.
At the top end of the core tube 24 of the continuous screw auger 22 there is disposed a tube connection 25 , to which the displacement head 40 (not illustrated here) is coupled non-rotatably.
On conclusion of the first drilling step, when the maximum movement distance of the drilling drive 16 has been reached and the continuous screw auger 22 penetrates the ground 2 over its entire length, the displacement head 40 forces the earth material 4 being conveyed upwardly aside into the wall of the bore hole 7 , as shown in FIG. 5 .
In the preferred exemplary embodiment, the displacement head 40 comprises an approximately central, cylindrical displacement section 42 , on the outside surface of which strip-shaped displacement elements 44 are disposed. A lower conical section 46 , the outside surface of which is provided with a lower helix 48 , is disposed below the displacement section 42 . The lower helix 48 serves to convey the removed earth material 4 into the region of the displacement section 42 .
The inverted cone-shaped lower conical section 46 is non-rotatably connected to the continuous screw auger 22 with the aid of the conduit connection 25 . The diameter of the lower conical section 46 continuously increases from the diameter of the core tube 24 to the diameter of the cylindrical displacement section 42 .
Conversely, an upper conical section 50 comprising an upper helix 52 is disposed above the displacement section 42 . The upper helix 52 has a counter-conveying direction in relation to that of the lower helix 48 so that earth material is conveyed by the upper helix 52 downwardly to the central displacement section 42 in the usual drilling direction.
The upper conical section 50 is of a regular conical shape, the diameter of which uniformly tapers from the diameter of the displacement section 42 upwardly to approximately the diameter of the bar-shaped extension 30 . The bar-shaped extension 30 is connected non-rotatably to the displacement head 40 via an upper tube connection 54 . | A drilling rig and a drilling method, in which the drilling element is caused to rotate and is displaced along a mast by means of a drilling drive, which drilling element has a continuous screw auger disposed below the drilling drive, and an extension, which is connected to the continuous screw auger and extends upwardly through the drilling drive. A displacement head is disposed between the continuous screw auger and the extension and is adapted to force earth material into the wall of a bore hole. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for analyzing a sample by electromagnetic irradiation and subsequently examining the particles emitted from the sample with the aid of a mass analyzer which forms part of the apparatus and which is accommodated in a vacuum chamber.
An apparatus of the above-outlined type is known and is disclosed, for example, in German Laid-Open Application (Offenlegungsschrift) No. 1,598,632. In this conventional arrangement, part of the sample is evaporated and ionized with the aid of high-energy electromagnetic radiation, in particular laser radiation, so that the location of impingement of the electromagnetic radiation can be used as an ion source for mass spectroscopy. In order to be able to extract the ions from the sample in the direction of the mass analyzer or in the direction of an electrode system disposed upstream of the mass analyzer, a suitable electrical potential difference must exist between the sample and the mass analyzer or the electrode upstream thereof. In this connection, reference is made to German Laid-Open Application (Offenlegungsschrift) No. 2,540,505. For an accurate analysis of the ion mass, it is of importance that this potential difference be the same, as closely as possible, for all ions emitted by the sample. This, for example, is no longer the case if, due to the emission of ions by the sample, the electrical potential changes at the locus of the evaporation of the sample material. The velocity of the ions reaching the mass analyzer then no longer corresponds to the applied accelerating voltage, but to the actual voltage difference between the locus of evaporation and the mass analyzer. Such a voltage difference is not known precisely and is not reproducible. Ions of the same mass can therefore enter the mass analyzer at different velocities which considerably worsens the resolution or even leads to measuring errors. The greater the energy of the laser pulse, and thus the number of ions generated, and the less the area of the sample under bombardment as well as the conductivity of the sample material, the greater such errors will become. The time required to compensate for this local charge must be short compared to the time of the actual measuring process.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus of the above-mentioned type in which the described drawbacks no longer occur.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, an electrically conductive layer of material is disposed in the zone of the sample.
Such a layer of conductive material which is preferably at the potential of the sample, ensures a completely even potential distribution in the zone of the sample. Such a layer effects a rapid charge equalization, so that always the same potential difference is determinative for the ions emitted from the sample and accelerated in the direction of the mass analyzer. Further, external potentials are prevented from having an influence on the locus of the analysis.
In case the apparatus conventionally has a glass-covered opening in one of the walls of the housing and an optical focusing system at the exterior of the covering glass for focusing the electromagnetic radiation through the covering glass onto the sample disposed below the housing, then the conductive layer, which is disposed preferably between the focusing system and the sample, is expediently essentially transparent, so that the electromagnetic radiation can reach the sample. The focusing system may then also serve for observing the sample under top- or trans-illumination, for example, in order to adjust the locus of analysis.
The layer of conductive material may be disposed on various components in the zone of the sample. It may be applied, for example, by vapor-deposition, to the side of the focusing system facing the sample or to the covering glass. Since the covering glass is often exchanged together with the sample, applying the conductive layer to the frontal face of the focusing system has certain advantages, at least with respect to the potential distribution.
In the alternative, it is also feasible to dispose the layer of conductive material on a carrier foil for the sample or, the entire carrier foil for the sample may be made of the conductive material. Or, the conductive layer may be vapor-deposited on the sample itself.
According to a further feature of the invention, the conductive layer is blocked with respect to the electrode (which extracts the ions) with a high capacitance and preferably a low inductance. Such an arrangement particularly enhances a prevention of change in potential by charge separation in the zone of the sample.
It is particularly expedient if the sample and the conductive layer have the same potential and are electrically insulated from the other components in the zone of the sample. Thus, a high positive or negative voltage may be applied to the sample, depending on the charge sign of the particles to be analyzed. This permits the use of a mass separation system at ground potential. If the mass separation is effected with the aid of a time-of-flight tube, this tube may be of simple construction since the heretofore required complex high-voltage insulation is no longer necessary. The above-mentioned measure also makes it possible to leave the mass separation system at the conventional negative or positive high voltage potential. This then doubles the acceleration voltage.
It is a further feature of the invention to arrange the layer of conductive material separately and insulate it electrically. This permits setting of a potential which is different from that of the sample, so that a further influencing of the field near the sample is feasible. By a suitable selection of the potential it is furthermore possible to extract not only ions but also electrons from the area between the sample and the conductive layer and to use them, for example, for calibrating the measured signal, since the number of the electrons is related to the number of ions generated and their degree of ionization. This extraction of ions or electrons can also take place between two electrically conductive layers disposed in the zone of the sample. Faster and weaker signals should then advisably be recorded by means of an arrangement having a low capacitance.
According to a further feature of the invention, a mesh is disposed between the covering glass and the sample. The mesh serves as a spacer and ensures that the covering glass is not also evaporated. The mesh may be made of a conductive or nonconductive material. If it is made of conductive material, it is preferably in electrical contact with the layer of conductive material to contribute to a rapid equalization of charges. If it is made of nonconductive material, it provides for an electrical insulation of the conductive layer.
In some particular cases it may be advisable, in order to influence the field near the sample, to provide two layers of electrically conductive material so as to multiply the possibilities for affecting the field near the sample, for example, for optimizing or adjusting purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 2 and 3 are schematic sectional views of three preferred embodiments of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIG. 1, the apparatus shown therein includes a housing 1 having an opening 2 that is sealed by means of a closure 3 in a vacuum-tight manner. The closure 3 has an opening 4 which is sealed--also in a vacuum-tight manner--by a covering glass 5. Outside the housing 1 there is arranged a focusing system which contacts the covering glass 5, preferably with the intermediary of a layer 6 constituted by an immersion liquid. Only the condenser lens 7 of the focusing system is shown. With the aid of the focusing system the electromagnetic (laser) beam is focused in the zone of a sample 8, so that an extremely small region of the sample is evaporated and ionized. The sample 8 is situated within the vacuum chamber 1 and is supported by the closure 3 in the opening 4 immediately behind the cover glass 5. The ionized sample particles with negative or positive charge are extracted by an electrode 9 which has a high positive or negative potential with respect to the sample 8 and which, for example, may simultaneously be designed as an ion lens. The ions enter a mass spectrometer 15 disposed in the vacuum chamber 1 and having a mass separator system, such as a time-of-flight tube. To assure that only the sample 8 is evaporated, with the exclusion of the covering glass 5, a spacer such as a mesh 10 is provided between the sample 8 and the covering glass 5. The thickness of the mesh 10 may be, for example, several tens of microns. It is further feasible to hold the sample between two meshes.
In the embodiment illustrated in FIG. 1, the side of the covering glass 5 facing the interior of the housing 1 is covered, according to the invention, with a layer of conductive material 11. The layer 11 is transparent to the ion generating laser radiation. The layer 11 ensures a uniform potential distribution in the zone of the sample, so that all ions traveling from the sample 8 to the electrode 9 are subjected to the same potential difference. The conductive layer 11 is blocked by a relatively large capacitance 12 with respect to the electrode 9 so that rapid charge equalization is assured. The inductance of the capacitance 12 should be as small as possible; preferably, it should be zero. If the spacer 10 is made of a conductive material (for example, if it is a copper mesh), it likewise contributes to the charge equalization since it is in direct contact with the conductive layer 11. The layer 11 and the sample 8 can have different potentials or identical high positive potentials, for example, 3000 V. For this purpose, a voltage source 16 is provided which is connected directly to the layer 11 and with the intermediary of a resistor 17, to the sample 8. If the resistor 17 is effective, the sample 8 and the layer 11 will have different potentials, but if the resistor 17 is bypassed as at 18, the potential on the sample 8 and the layer 11 will be identical. An electric insulation of the layer 11 is ensured by making the closure 3 and the mesh 10 of an insulating material.
Turning now to FIG. 2, the embodiment shown therein differs from the FIG. 1 embodiment in that the sample 8 is supported by a carrier foil 13 to which the conductive layer 11 is applied. In such an arrangement a further layer 11' may be additionally provided on the interior of the glass 5 as in the embodiment of FIG. 1. The additional layer 11' may have a different potential from those of layer 11 and sample 8. The mesh 10 and/or the foil 13 may serve as insulators in case they are made of electrically insulating material.
In the embodiment of FIG. 3, the conductive layer 11 according to the invention is at ground potential and is applied to that side of the focusing system which faces the sample 8. Such an arrangement is of advantage if during every change of samples, the covering glass and other elements also have to be exchanged. Thus, the conductive layer 11 being permanently present on the focusing system, the new covering glass or other new components need not be provided in each instance with the conductive layer. It is to be understood that any other potential may be applied to the layer 11 if desired.
The layer 11, may, for example, essentially consist of In 2 O 3 -SnO 2 or of a thin layer of carbon or gold. Its thickness and consistency should be so selected that it is still transparent for the laser radiation. If the layer 11 is disposed so close to the sample 8 that part of it is also evaporated, then this material can also be utilized to calibrate the mass spectrometer.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents in the appended claims. | An apparatus for analyzing a sample by electromagnetic irradiation includes a vacuum chamber, a support for holding the sample in the vacuum chamber, an arrangement for irradiating the sample with an electromagnetic beam, a mass analyzer disposed in the vacuum chamber, an arrangement for extracting particles from the sample and introducing them into the mass analyzer and a layer of conductive material situated in the vicinity of support in the zone of the sample. | 7 |
This application claims priority from Provisional Application No. 60/195,094 Filed: Apr. 6, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved control valve for a pressurized water closet that precisely regulates the refill volume of a toilet bowl.
2. Related Art
The basic components of a pressurized water closet are a water vessel, a flush valve and a flush valve actuator. The aforesaid components are generally installed internally of a conventional water closet. The pressurized water closet is energized by water pressure from a conventional fresh water supply system.
In operation, as the water level rises in the water vessel after flush, air internally of the water vessel is compressed. When water pressure in the vessel equals the supply line pressure or when it causes the pressure regulator valve to shut, in the event of supply line pressure greater than that allowed by the regulator, flow of water into the water vessel ceases and the system is conditioned for operation. When the flush valve actuator is actuated, the flush valve opens whereafter the compressed air in the water vessel pushes the water stored therein into the water closet bowl at relatively high discharge pressure and velocity, flushing waste therefrom with minimum water consumption.
The aforesaid features of the pressurized flush system result in stronger and more effective extraction and drain line carry, cleaner bowls, fewer drain line clogs, no hidden leakage of water between flushes, and smaller sized pipe systems. The system produces a flushing action which clears and cleans a toilet bowl while consuming less than one and six tenths gallons of water while meeting the highest municipal codes. The toilet bowl is emptied by one flush without drain line “drop-off” common to many low water volume, or gravity-flow type toilets.
In operation, actuation of the manual operator creates a pressure differential across a flush valve piston disposed in a flush valve cylinder. The flush valve piston and a flush valve therefore move upwardly at a controlled rate.
Upward or opening movement of the flush valve permits water to be ejected into the toilet bowl from the water vessel under relatively high pressure effecting extraction of the contents of the toilet bowl. Flush commences simultaneously with manual depression of the flush valve actuator and is time controlled so as to produce a prolonged high energy surge of water which carries bowl waste into the sewer.
Closure of the flush valve is timed by the distribution ratio of incoming water to the upper chamber of the flush valve cylinder and the water vessel. When the manual flush valve actuator is released, the fluid flow path from the upper chamber of the flush valve cylinder to ambient is closed. At this point, a predetermined portion of the water supplied under pressure from the water supply system flows directly to the upper chamber of the flush valve cylinder. The remaining portion of water supplied by the system flows to the main chamber of the water vessel. When the upper chamber of the flush valve cylinder is filled, and the flush valve is closed, all incoming water is directed into the water vessel.
Water rising in the water vessel under regulated water system pressure compresses the air entrapped therein until it reaches either the line or regulated pressure of approximately 30 psi, whichever occurs first. At this point, flow stops and the system is ready to be flushed again.
SUMMARY OF THE INVENTION
Current control valves for pressurized water closet flushing systems do not permit the ready and simple adjustment of the predetermined portion of the water supplied under pressure while maintaining a flush action independent of actuator depression and a self cleaning action.
Specifically, the present invention provides a ready and simple manual adjustment of the amount of water to be provided in a flush (the refill volume) while maintaining a flush action independent of actuator depression. The present invention also provides a self cleaning action.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a water closet flushing system.
FIG. 2 is a cross sectional view taken along the line 2 — 2 of FIG. 1 of a fully charged pressurized water closet flushing system according to the prior art.
FIG. 3 is a cross sectional view of the instant invention wherein the metering pin is maximally advanced.
FIG. 4 is a view similar to FIG. 1 wherein the metering pin is minimally advanced.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in FIGS. 1 and 2, a pressurized water closet flushing system 110 , in accordance with the prior art represented by U.S. Pat. No. 5,970,271 to Martin, et al, is shown in operative association with a conventional water closet tank 112 . Major components of the system 110 are a water vessel 114 , an internal flush valve assembly 116 , and a manifold 18 comprising an integral flush valve actuator 122 , a water pressure regulator 124 , an air induction regulator 125 , a disinfectant reservoir 126 .
Water is supplied to the system 110 from a pressurized source (not shown) and flows upwardly without restriction through an inlet conduit 127 and vacuum breaker 128 , thence laterally to the manifold 118 . Water is free to flow through the conduit 127 to the manifold 118 at system pressure thence, after regulation, to both the flush valve assembly 116 and water vessel 114 , as will be described.
In the preferred constructed embodiment disclosed, the water vessel 114 comprises a pair of vertically stacked half sections 132 and 134 . The upper section 132 of the water vessel 114 has a pair of downwardly extending partitions 135 and 136 that create isolated chambers 137 and 138 , respectively as long as the water level is above the weld joint between the sections 132 and 134 of the water vessel 114 , a typical condition between flushes. Accordingly, because the compressed air in the chambers 137 and 138 which powers the system 110 is isolated, a leak in an upper portion of the flush valve assembly 116 will not result in the system 110 becoming waterlogged.
The manifold 118 , comprising the water pressure regulator 124 , air induction regulator 125 and flush valve actuator 122 , is mounted on the upper section 132 of the water vessel 114 .
The manifold 118 also includes the flush valve actuator 122 according to the existing art, which comprises a cylindrical housing 180 with a manually operable spool 182 disposed internally thereof that is slidably journaled in a sleeve 184 . The spool 182 carries a valve 185 that is normally seated on a valve seat 186 . A needle valve 187 is supported on one end of the spool 182 so as to extend into an orifice 188 in the housing 180 to define the area of an annular water inlet orifice that controls the flow of water to the flush valve 116 .
Movement of the spool 182 of the flush valve actuator 122 against the bias of a spring 192 moves the valve 185 off its seat 186 to open communication between an upper chamber “C” of the flush valve 16 , through an orifice 94 to a pressure relief tube 96 to initiate flush. The tube 96 communicates with ambient pressure in the toilet bowl (not shown).
In operation, the water vessel 114 is fully charged with air and water and the system 110 is ready for flush. Zones (A), (B), (C) and (E) are pressurized. Zones (D), (F) and (G) are at atmospheric pressure. Flush occurs when the actuator spool 182 of the flush valve actuator 122 is depressed, allowing pressurized water in zone “C” to discharge through the actuator 122 into zone “D” thence to zone “F” as well as to flow through the water inlet conduit. The pressure differential established between zone “E” and zone “C” forces the piston 216 of the flush valve assembly 116 to life, creating an escape path for water in zone “E” through the discharge aperture 209 into the toilet bowl at zone “F”. It is to be noted that the piston 216 of flush valve assembly 116 lifts, for example, 0.40 inches, discharging only a corresponding volume of water from zone “C”. This volume of water is determined to be the amount of water capable of being discharged through the flush valve actuator 22 in ¼ second. As a result, the same amount of water is required after each flush to refill zone “C” and cause the flush valve 210 to seal regardless of whether the spindle 182 of the flush valve actuator 122 is depressed for more than {fraction ( 1 / 4 )} second.
As flush progresses, pressure in zone “E” begins to lower, allowing the regulator 124 to begin opening and flow to begin through zone “A” to zones “B” and “C”, flow through zones “A” and “B” is at maximum when pressure within vessel “E” is zero.
It is to be noted that the size of the needle valve orifice 188 in conjunction with the needle valve 187 controls the flow rate of new water into the upper chamber “C” of the flush valve 116 . Clogging of the annulus by particles in the water supply system is minimized because, when depressed, the needle valve 187 clears any foreign matter that lodges in the orifice 188 .
Refill volume of the toilet bowl utilizing this existing valve actuator can be varied by varying the diameter of the orifice 188 in conjunction with the diameter of the needle valve 187 , which varies the ratio of water passed into zone “C” respectively, thus speeding or slowing movement of the piston 216 and closure of the flush valve assembly 116 after flushing and/or the amount of bowl refill water passed through the water vessel 114 to the toilet bowl (not shown). As a result, the system 110 can be precisely tuned to different bowl configurations to obtain maximum water conservation and performance. The present invention provides an external manual adjustment for the bowl refill volume.
Referring to FIGS. 3 and 4 and in accordance with a preferred constructed embodiment of the instant invention, an adjustable fluid metering valve 10 comprises a generally cylindrical housing 20 with a manually operable spool 22 disposed internally thereof that is slidably journaled on a sleeve 24 . The spool 22 has an externally threaded portion 26 at one end thereof that rotatably engages a generally right circular cylindrical valve stem 30 .
The valve stem 30 is slidably journaled in the cylindrical housing 20 and has a plurality of longitudinal slots 32 therein, that engage a plurality of tabs 36 protruding from the interior of the housing 20 , restricting or preventing rotation of the valve stem 30 with respect to the housing 20 . The valve stem 30 further has an internally threaded portion 38 that is engaged by the externally threaded portion of the spool 22 . In another embodiment, the present invention includes a splined valve stem, illustrated in FIG. 6 . The FIG. 6 embodiment includes a valve wherein the housing 120 has at least one groove 132 receiving a longitudinal spline 131 on the valve stem 130 .
The spool 22 is rotated by an external manual adjustment knob 50 . As the spool 22 rotates, the valve stem 30 is restricted from rotation, thus is driven by the rotation of the spool threads to slide inwardly or outwardly, depending upon the direction of rotation. A needle valve pin 40 is supported on one end of the valve stem 30 so as to extend into an orifice 60 in the housing 20 to define the area of an annual water inlet orifice that controls the flow of water to, for example, a flush valve in a water closet.
The orifice 60 in conjunction with the needle valve pin 40 of the instant invention minimizes the lodging of any foreign matter in the orifice as the needle valve pin 40 can be readily advanced therein to clear any obstruction. The maximum diameter of needle valve pin 40 is less than the diameter of orifice 60 .
In conjunction with a pressurized water closet, as for example disclosed in U.S. Pat. No. 5,970,527 to Martin, et al, as shown in FIGS. 3 and 4, the refill volume of a toilet bowl can be varied by varying the diameter of the orifice 60 by advancing the needle valve pin 40 therein, which varies the volume of water passed into a pressurized chamber of the water closet (not shown) to obtain maximum water conservation and performance. Further, the valve pin may be tapered to allow for a more dramatic variation of volume control for a given rotation of the control knob.
While the preferred embodiment of the invention has been disclosed, it should be appreciated that the invention is susceptible of modification without departing from the spirit of the invention or the scope of the subjoined claims. | An improved control valve for a pressurized water closet, having a housing, a spool rotatable within the housing, a valve stem threading engaging the spool but fixed from rotating relative to the housing and a needle valve extending from the valve stem and into the housing orifice, creating a self cleaning valve adjustable by rotating the spool, which adjusts the depth of the needle valve in the orifice, and thus adjusting the effective opening of the orifice. | 8 |
RELATED APPLICATION DATA
This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 60/423,567, filed Nov. 5, 2002 entitled “POWER PODIUM PRESENTATION DISPLAY APPARATUS WITH ENVIRONMENTAL CONTROLS,” which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Aspects of the invention generally relate to presentation systems, and more particularly to presentation systems having associated controls that are at least capable of manipulating various aspects of the presentation environment.
2. Description of Related Art
Currently, whenever someone prepares to give a presentation at an unfamiliar venue, he or she must adapt quickly to the environment found at the location where the presentation will be made. Depending on the size of the conference facility, hotel, or other corporate building, the speaker may find a wide range of devices and functionality available. The speaker either will bring a laptop or use one provided by the facility, each of which may differ from a “standard” laptop (since there is no standard design for laptops). Once the speaker has the laptop or other computing device available, he or she must next determine the type of software available to use for the presentation. Although there are some software packages that are dominant in this area, they are by no means universal. The speaker must load the presentation onto the laptop, assuming the data storage media of the presentation file can be accommodated by the storage drives available on the laptop. Because the size of presentation files frequently exceeds the capacity of 3.5″ inch floppy discs (1.44 MB), compact discs (CDs) typically prevail. If the speaker does not have the right media, some sort of transfer must take place—either a new medium is used or another computer is used to transfer the data to the presentation computer. At this point, the speaker must hope that the projector and video signal from the computer are compatible with each other, and that they are correctly integrated. During the presentation, the speaker must rely on others to modify the environment at the appropriate times, e.g., someone to dim or raise the lights as presentations begin and end.
Additionally, when the speaker arrives at his hotel for his presentation, he or she often focuses (sometimes as if by surprise) on the need to practice the presentation before delivery. Not infrequently the speaker then calls the meeting organizer and asks if he or she can set up the presentation in the meeting room and make sure “everything is working OK.” The meeting organizer dutifully calls the hotel conference services manager and begs for the meeting room (which may or may not be available) and suitable AV equipment. Note that an LCD projector can rent for a significant cost. The speaker only rarely has available a system by which he or she can videotape the presentation for practice.
Due to the variety of hardware choices, the energy invested in learning the equipment often causes a corresponding drop in the quality of the presentation. The hardware is often owned by the facility and therefore the energy invested in learning about it is only useful in the short-term.
SUMMARY OF THE INVENTION
An exemplary embodiment of the Integrated Information Presentation System With Environmental Controls aims to alleviate many of the problems associated with making presentations of all types, and making them easier to give and of a higher quality to receive. The Integrated Information Presentation System With Environmental Controls comprises a combination of an Integrated Information Presentation Device (also known as a PowerPodium), an Integrated Presentation Environment Assembly with Controls (also known as a Presentation Booth), a Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices a stylus, and a remote control. With the Integrated Information Presentation System With Environmental Controls, every technical aspect of a presentation is capable of being enhanced, as well as providing the speaker an opportunity to enhance his or her skill in giving a presentation.
Applications for the Integrated Information Presentation System With Environmental Controls include, but are not limited to, enhancing speaker performance, enhancing audience experience, providing a mini production studio, providing a remote viewing station, viewing pre-recorded presentations, and providing a consistent experience for audiences in varied locations simultaneously or, for example, at different times. Other applications include, but are not limited to, residential applications such as remote family reunions, family history presentations, home movie presentations, birthday celebrations, or remotely configuring security measures. Additional applications include, but are not limited to, remote learning classes, virtual sports spectating, virtual tours, virtual tours of vacation spots, virtual tours of houses for sale, virtual small group meetings, remote religious worship experiences, remote auction bidding, and the like. It is to be appreciated that the application of such a system is rich and varied, covering almost any event where sight or sound is important.
A speaker can load the presentation on the Integrated Information Presentation Device, interfaced with the electronic devices in the room to the degree the facility desires, which allows him or her to control the environment of the speaker, the audience, even remote audiences. Using the stylus, a presenter can use both the hardware and software controls to navigate the presentation slides, adjust the environmental conditions, interact with an assistant behind the scenes without disturbing the audience, and even point to highlight items using the imbedded laser pointer, or the like. In addition, a robust remote control is described that provides virtually every possible function of the Integrated Information Presentation Device while allowing the presenter to move about the room. In addition, the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices allows the speaker to use a handheld computing device as, for example, a remote control and as a stand-alone substitute for the Integrated Information Presentation Device.
Using the Integrated Presentation Environment Assembly with Controls (also known as a Presentation Booth), the speaker can practice the presentation on, for example, identical equipment, or equipment configured to emulate to what is in the presentation room, without tying up a valuable facility resource. Because the Integrated Presentation Environment Assembly with Controls is compact, it can be located in low-traffic, sparsely used spaces of the facility. Since the features and controls of the Integrated Information Presentation Device are rich and varied, the experience gained in becoming familiar with them will enhance the total experience of both presenter and audience.
In addition, the Integrated Presentation Environment Assembly with Controls may also function as a mini recording studio or broadcasting studio. The speaker may record a presentation using the Integrated Presentation Environment Assembly with Controls on video or other storage means to be distribute the presentation over electronic means such as the Internet, or copy the presentation to more permanent means such as a floppy, DVD or CD for distribution. The Integrated Presentation Environment Assembly with Controls may also be used to broadcast a live presentation as well.
An exemplary embodiment of the Integrated Information Presentation Device (also known as a PowerPodium) aims, for example, to alleviate many of the problems associated with making a presentation to an audience, and to provide a means by which the speaker can control many of the environmental variables affecting the presentation without the need for the assistance of another person. Although another person is preferred to help operate the message center, FIG. 1 , item 2 B, it is not necessary to have anyone other than the speaker involved for any other function once the Integrated Information Presentation Device is set up for the speaker.
An exemplary embodiment of the Integrated Information Presentation Device can be housed, for example, within a podium or lectern, or it may be a smaller unit capable of being transported and placed on a table, lectern, podium, or other apparatus as may be used by speakers while they present. The Integrated Information Presentation Device may be set up, for example, semi-permanently in one presentation room, or it may be moved from room to room to enable more flexibility to a conference center.
At its most general, the Integrated Information Presentation Device is concerned with displaying a speaker's presentation, and as such, utilizes the use of, for example, a display (such as, but not limited to, a flat-panel display), a long term storage device (such as, but not limited to, a magnetic hard drive), various temporary storage devices (such as, but not limited to, a floppy drive), controls to enable the speaker to change the presentation environment (such as, but not limited to, lighting), various transmission devices to relay the commands to external devices controlling the environment, and optional devices to relay information to the speaker. One exemplary embodiment of the Integrated Information Presentation Device would have two separable parts, a “Detachable Presenter Unit” and a “PowerPodium Central Unit.” The “Detachable Presenter Unit” could contain all hardware integral to control the presentation and the environment as it is given. The “PowerPodium Central Unit” may be placed nearby (on the order of a few feet), but out of sight to provide a clean view for the audience. The “PowerPodium Central Unit” could have the hardware and software essential to the operation and processing of presentation software, message center, and other commands, as well as the removable storage interface devices. The two separable parts may be connected by electrical wire, fiber-optic cable, wireless technology, or some other communication technology.
Thus, when using the Integrated Information Presentation Device, a speaker may prepare a presentation and store the presentation on a removable storage medium. The speaker may take this removable storage medium to the conference center, lecture hall, or other presentation site that has an instance of the Integrated Information Presentation Device ready for use. The removable storage medium is then inserted into the appropriate slot, chamber, or other opening or cavity of the removable storage device (e.g. the 3½″ floppy drive 45 if the presentation is stored on a 3½″ floppy disk) located on the Integrated Information Presentation Device. The appropriate presentation software is then initialized and the data from the removable storage is read and optionally saved to the internal long-term storage device, for example, a hard drive. It should be appreciated that any means of transferring files, including but not limited to wireless transfer can be used to get presentation files onto the Integrated Information Presentation Device. Once this is done, the speaker may begin the presentation, or may come back later and begin the presentation. Alternatively, the Integrated Information Presentation Device may be set up with “Agenda File Organizer” software, particularly in meeting or conference settings in which there may be more than one speaker or presenter. The Agenda File Organizer software is software code (for example, a program, a module, a dynamically linked library, etc.) which displays file names from the speaker's removable storage medium and enables the technician, speaker, or other set-up person to copy the files into an appropriate folder or directory. The Agenda File Organizer software is also software code that runs as the interface for each speaker throughout the conference or other speaking event to quickly have his own files loaded into the presentation software. An exemplary purpose of the Agenda File Organizer software is to arrange the availability of presentation and other files in an orderly manner, in order to facilitate the quick and smooth transition from one presenter to another without interruption. The Agenda File Organizer software can be activated (or can be auto-activated) to run, for example, whenever a removable medium is inserted into the Integrated Information Presentation Device. While the Agenda File Organizer software may be used to enable speakers to load their own presentations, it is more likely that a technician from the conference facility would use this to set up the files needed for the day, week, or possibly even month. The agenda file organizer software files might include, but are not limited to, the agenda file organizer software code, modules, libraries, data files and command files, presentation files, speaker introduction files, advertisements, announcements to be displayed during breaks, pictures, text files, or files used to enhance the entire conference experience, not just the presentation. The Agenda File Organizer software may also contain information about the order and time of the presentations to “automatically” load the appropriate presentation at the appropriate time. The Agenda File Organizer software may also store preferences, for example, in a profile, concerning the environment setup the speaker prefers, if the speaker is a frequent user of that particular instance of the Integrated Information Presentation Device. Besides easing the transition between speakers, this would give, for example, each speaker the sense that the machine is set up “just for him” for the time of his presentation. The presentation file (and any other appropriate files) may be copied to an internal hard drive for later use, thereby enabling the speaker to “save” his presentation on the particular instance of the Integrated Information Presentation Device he will use, and to keep the removable media elsewhere as a “backup.” While some computer users may not need such software, it may be desirable to have this available as an option for those speakers who are not as comfortable manually controlling this process. While performing this transfer, or at any point interaction with software is required, the user may use, if available, the keyboard, the touch screen, the stylus (active and/or passive) or the “Pointer Control Device.” The “Pointer Control Device,” for example a mouse or a trackball, can be used to control the user interface pointer in many software packages and operating systems.
Before beginning the presentation, the speaker may adjust the room environment using the various controls installed on the Integrated Information Presentation Device. In an exemplary embodiment of the Integrated Information Presentation Device, the speaker will have the ability to adjust the environment using such things as, but not limited to, lighting controls, window lighting controls, presentation screen controls, sound controls, microphone controls, temperature controls, and air flow controls. It is to be appreciated that any aspect of a presentation environment that can be altered by artificial means can be incorporated easily into the Integrated Information Presentation Device. The speaker can adjust the environment to the conditions he or she thinks are best for viewing the presentation. For example, the speaker may adjust the lighting level to be dim but not dark using the lighting controls, promote air circulation by adjusting the air flow controls to produce a low velocity breeze for the audience and adjust the temperature to 70 degrees Fahrenheit using the temperature controls. If a situation arises before, during, or after the presentation that needs immediate attention, the speaker has control of the situation at his fingertips. For example, the speaker can mute all sound output from the Integrated Information Presentation Device using the mute button to silence any high-pitch feedback that commonly occurs with sound systems, or mute all sound while people are entering and exiting the room. One possible embodiment of the Integrated Information Presentation Device will allow the “retrieval” of settings from a previously saved environment modification using the “Shortcut Mode Buttons.” Thus, a speaker may set up an “exit” environment which provides full overhead light for people to see their way into or out of the presentation area, while turning off the input from all microphones and the output of all speakers. Another “saved” environment mode may be that for a general presentation which sets the temperature at an appropriate level, adjusts the air flow as appropriate, lowers the lights, turns on the audio speakers and the speaker's microphone, lowers the presentation screen, and lowers the window shades. Of course, once these modes are executed, minor adjustments can be made by the speaker using the appropriate controls on the face of the Integrated Information Presentation Device. The controls may act like a type of remote control that sends the appropriate signals to external devices, which have been installed in the conference center's wiring. These signals may be transmitted by, for example, Infrared Ports, RF Transceiver Ports, or other energy transmission means, wireless or otherwise. The external devices may act directly on the signals from the embedded buttons, or the devices may take their signals from a central transmission point, which is controlled by the processing unit. For instance, when the speaker moves the control on the Integrated Information Presentation Device to dim the lights, a signal may be sent from the Integrated Information Presentation Device to an external device, such as a “dimmer,” previously installed in the conference center room's electrical circuit. This signal may come from the lighting control module directly, or it may be processed and sent from the processor and one of the output devices of the Integrated Information Presentation Device. The external device would respond in either case appropriately and dim the lights. This arrangement will, however, require the conference center to install such devices in its circuitry prior to the presentation (probably a long-term installation by professionals according to local electrical codes), although this may be as simple as having a regular three-way or dimmer switch installed. Alternatively, small temporary devices, not unlike timer plugs common in many homes, may be temporarily inserted in any non-permanent circuitry, for example, when a plug is inserted directly into a wall outlet. If multiple instances of the Integrated Information Presentation Device are to be used in close proximity, for example in a large conference room with multiple presentations occurring, there will need to be a way to distinguish between signals. If a conference center has purchased more than one Integrated Information Presentation Device, it may not desirable for the commands of one instance of the Integrated Information Presentation Device to be received by another device being used in another room. Thus, to prevent the lights in multiple conference rooms from being brightened when one speaker adjusts the light control on his instance of the Integrated Information Presentation Device, either the rooms must be shielded from the transmitted energy from another room, or the devices should have distinguishable or identifying signals. Two of the ways, for example, this may be accomplished are by varying the frequencies the individual Integrated Information Presentation Device send and receive, or by providing an identification string at the beginning of a command sequence (it should be appreciated that there are other methods as well).
Alternatively, software may optionally be included to allow a user or technician to bring up a table of stored settings for various situations, time of day, speakers, and events, from which a selection is made and the Integrated Information Presentation Device produces control signals to various external devices controlling aspects of the speaking environment. These stored profiles may be completely user definable, or they may be static settings, or some combination thereof. Additionally, files containing task queues may be used, where each task has an associated time or point of presentation, in order to provide some automation to the changing of settings during a presentation. In an extreme case, with all the appropriate files on hand with command queues, the giving of a presentation may be fully automated—even to the point of needing no live speaker. This may be desirable especially in venues such as, but not limited to, movie theaters, church sanctuaries, public meeting places, concert halls, stadiums, and historical venues.
Once the environment has been set according to the speaker's preference, the speaker may turn his or her attention to the presentation to be given. The Integrated Information Presentation Device will be running presentation software, loaded with the speaker's presentation that had been prepared and loaded at some earlier time. The presentation will begin and the speaker will see a “speaker's version” of the presentation (as is common in some currently popular presentation packages), while the audience views only the “presentation slide” format. This is accomplished, for example, by using the two monitor outputs of the Integrated Information Presentation Device. One of these outputs, for example, may be internal and connected to the primary display, as is common in many devices known as “laptop computers.” The other output, usually, but not necessarily on the external surface of the Integrated Information Presentation Device, will be connected, for example, to an image projection unit by electromagnetic, optical, wireless, or other communication technology from the Integrated Information Presentation Device to the image projection unit (this may or may not be accomplished with a physical line). This projector will display the incoming video signal on the projection screen, for example, or some other surface provided that is conducive to watching presentations. In another alternative embodiment of the Integrated Information Presentation Device, two screens may be built into the Integrated Information Presentation Device, with one facing the speaker and the other facing the audience (this screen may be adjustable for various heights and angles). This alternative embodiment is especially useful for situations where very small groups are presented to, or where the speaker is often traveling quickly between small group presentations.
During the presentation for example, the speaker may stand at the podium to directly interact with the Integrated Information Presentation Device as he goes through his slides, or he may use a remote control unit to enable him to move about the audience while still controlling the presentation through the Integrated Information Presentation Device. If he chooses to stay at the podium, he may use the “Next slide” and/or “Previous slide” buttons to control paging of the presentation slides. He may also access pages on the Internet using software activated by pressing the “Internet” button. Using, for example, the built-in trackball, he can then, for example, choose a site from a list of favorites, follow a link displayed on the screen, or type in the address with the keyboard of a document on a site by selecting the “address bar” with the trackball or “tab” key. The speaker may, for example, swap the Internet browsing software and the presentation software using the two keys provided on the Integrated Information Presentation Device (marked “Internet” and “Presentation”). At any time the speaker may black out (or white out) the audience screen using the key provided to enable him to perform functions with the software with which he would not want to distract the audience. After the presentation, it may be that the speaker will be asked a question about a slide he has shown. The speaker can then use the “Slide Sorter View” button, which will black out the screen and open, for example, a “slide sorter” view as is found in some common presentation software. The speaker will be able to find the slide to which the question refers and select it for viewing on the main screen. Once the slide has been selected, the speaker enables the audience view by re-pressing the black out key (which reverses the operation performed when the slide sorter view button was pressed). A button with the capability of muting all sound output from the device to keep extraneous noise from being generated during breaks, or times where there is feedback from the microphones, may be included on the Integrated Information Presentation Device. Optionally, a clock to view the time of day, as well as a timer which can be set at the beginning of a presentation to show the time remaining in the current session may be included on the Integrated Information Presentation Device. Optionally, a stylus (which may be active or dumb) provides, for example, the means for the speaker to select items on a touch-sensitive screen (or other feedback screen), or to utilize the “mark-up” slide feature found in some presentation packages.
If, at any time, the speaker needs assistance from the conference center or audiovisual team, he or she may press the “Assistance Required Button,” optionally designated by a red button marked with an “H” for “HELP.” Alternatively, or additionally, if assistance is needed, the Assistance Required Button may send a message, for example via e-mail, to a predetermined person. This button will trigger an output response such as, for example, a signal to a remote device to alert a helper, technician, or other appropriate personnel at a designated place in the building that immediate assistance is needed in the conference room. Since this button should be protected from accidental activation, it may, for example, be equipped with a raised rim, a flip cover (not unlike sensitive controls used in airplanes), or both. Once activated, the signal should continue until the speaker deactivates it by means such as, but not limited to, pressing the button a second time, or until it is deactivated by means of the response by the conference or audio-visual team.
An assistant may be utilized to provide feedback to the speaker during the presentation using the Message Center. This assistant could be in another part of the presentation room with an interfacing device, such as but not limited to a computing device connected through the local intranet or network, a computing device connected through the Internet, a computing device connected through wireless technology, or other similar means, analyzing the presentation itself, looking for audience reactions, and determining the right emphasis of the material. This assistant could send messages such as, but not limited to, “Explain point 3 more thoroughly,” “Don't forget to highlight X,” “You are losing the audience's attention,” or even “You are out of time!” Another use may be that of filtering questions at the end of a presentation, rather than having an open Q&A session. This would enable the assistant to take the most insightful and relevant questions, or the most common questions, and have the speaker address them, without the fear that some audience member might monopolize the time with an arcane point. This Message Center may be accomplished with such similar technology as, but not limited to, popular “Instant Messaging” software, email software, or it may be a direct link from the assistant's the interfacing device to the speaker's (perhaps through a direct connection between the two computers, wireless technology, the Internet or through a server computer in the presentation facility). Questions before, during, or even after the presentation could be sent to the speaker (through the assistant and message center) from a handheld computing device, a cellular phone capable of sending text messages, a two-way pager type device, or any other device capable of transmitting a text message from one point to the appropriate channel to reach the speaker and/or the speaker's helper.
A remote control can also be used with the system. In particular, a remote with pointer activation button, pointer lens, lighting controls, previous slide button, next slide button, sound controls, microphone controls, Internet button, presentation screen button, time of day display, presentation time elapsed, and presentation time remaining is described. The remote control may be used by the speaker even if he or she remains at the podium, since the remote may contain a built-in laser pointer. This enables the speaker to point out specific items on the slide whether or not he or she is near the screen. One exemplary embodiment of the remote control has many of the function controls of the Integrated Information Presentation Device built into it. The signal from the remote control may be transmitted through wires, although it is more desirable to have the remote use wireless technology to allow more freedom to the speaker as he presents. The controls that may be built into the remote control include, but are not limited to, lighting controls, sound controls, microphone controls, “Internet” and “Presentation” swapping buttons, as well as “Next slide” and “Previous slide” controls. There may also be a time of day display, “presentation time elapsed”, and “presentation time remaining” displayed on the remote control. These may be synchronized with the time displays on the Integrated Information Presentation Device (also known as PowerPodium) (which might have been accomplished, for example, when the remote control was in the Remote Control Storage Compartment of the Integrated Information Presentation Device, as the presentation is set up), although it may not be necessary to do anything more than have the speaker “synchronize” them himself. The remote control may also be configured to transmit commands to operate a VCR, if the speaker desires to use videotape in his presentation. These commands, for example, may be transmitted directly to the VCR (requiring the remote control to be set up to interact with the correct type of VCR, similar to store-bought replacement remotes), or they may be transmitted back to the PowerPodium Central Unit, where they would be processed, and the appropriate signal sent then to the VCR. It should be appreciated that any feature controls of the Integrated Information Presentation Device may be incorporated into the remote control.
Additionally, it should be appreciated that many of the controls of the Integrated Information Presentation Device may be implemented using software rather than hardware. For instance, many of the buttons on the top face of the Integrated Information Presentation Device may be implemented as software controls or buttons as images on the display 2 —not unlike buttons and controls found in web pages, games, or productivity software. This may be implemented using a larger display screen (including, but not limited to, a touch-screen) which could occupy the bulk of the top surface of the Integrated Information Presentation Device. The actual design behind the scenes should make little difference to the user beyond whether he pushes a button or selects an image of one on the screen. The software implementation of these functions may require the processor to process these inputs before sending the appropriate signals to the desired device. This implementation may require far less hardware, but it may require a more sophisticated processing program.
Since numerous embodiments of the Integrated Information Presentation Device can access the Internet, a speaker may use the Integrated Information Presentation Device (using an instance of one such embodiment), for example, to set up an online viewing (remote viewing) of the conference speaker and his or her notes using the Internet access connection. Depending on the quality of video desired, one may set up, for example, a digital video camera (referred to in some embodiments as a “web-cam”) to be connected to the Integrated Information Presentation Device to stream the signal to the web, or it may be necessary to set up an alternate connection to the web using a separate device, if the video quality desired is so high as to affect the processing of the presentation, and therefore the presentation itself.
Additionally, the speaker may desire to distribute the slides, using translation software integral to one embodiment of the Integrated Information Presentation Device, in a variety of languages that can be selected individually by members of the audience. The conference center or meeting facility may have installed server and terminal equipment in the presentation rooms in which this feature may be used. The terminals may comprise LCD screens and related equipment located on the seatbacks directly in front of the respective audience members, or in alternate configurations of the audience chairs, in which the terminals are linked to the Integrated Information Presentation Device via the server. An interface or network connection may be established by which the audience member connects his own laptop or personal digital assistant (PDA) to view the presentation in the alternate language format. Additionally, a human translator may be provided for every language appropriate to translate the words the speaker says during the presentation for audience member speaking that language. This translation may be disseminated using wireless communication devices as is common already in some venues, or it may be disseminated through data in the interface or network connection. It should be appreciated that as speech recognition programs become more sophisticated, and as translation programs develop, that these new features would be easily incorporated into the Integrated Information Presentation Device.
An exemplary embodiment of the Integrated Presentation Environment Assembly with Controls (also known as a Presentation Booth) aims, for example, to alleviate many of the problems associated with preparing for a presentation in an unfamiliar environment or using unfamiliar equipment. It also aims to provide a way for speakers to practice, record, or broadcast a presentation from a compact environment, rather than a classroom or meeting room. The Integrated Presentation Environment Assembly creates substantial benefit for, for example, the speakers, the audience members, the sponsoring organization, and the hosting facility.
The speaker now has an efficient, convenient and vastly improved system for practicing his or her presentation. For example, upon checking into the hotel, the speaker will receive an encoded card, prearranged by the sponsoring organization, which will gain him or her access to any available Integrated Presentation Environment Assembly with Controls (Presentation Booth) at the hotel. This eliminates unnecessary delay for the speaker and unnecessary staff cost for both the sponsoring organization and the hosting facility.
The audience will benefit from having speakers who are better prepared at giving a particular presentations and a better overall meeting experience because the Integrated Presentation Environment Assembly with Controls allows them to practice with the Integrated Information Presentation Device and all of its features before coming in to the lecture hall. Continued benefit to all will continue to be realized as the Integrated Information Presentation System with Environmental Controls becomes the standard for presenters.
The sponsoring organization, which often earns praise or criticism based upon the quality of presentations at its conferences, can look forward to speakers who are better prepared. As a result, the organization's customers—the meeting registrants—are happier and more likely to attend the same conference in future years.
The facility hosting the presentation is now able to provide a superior service to its customers, and can provide that improved service in a way that is more conserving of its personnel costs. The hotel now can be confident that the service will be available when the customer needs it, that it will be state of the art, and that it will eliminate the crisis atmosphere that frequently accompanies speaker preparation.
In addition, the Integrated Presentation Environment Assembly with Controls may be used as a recording studio to enable speakers to produce a presentation to be distributed through or to a website, various media formats, and even live-feeds to remote audiences.
Another use of the Integrated Presentation Environment Assembly with Controls is for remote participation or viewing of presentations (conferences, seminars, and other events). An additional application of the Integrated Presentation Environment Assembly with Controls is to provide “virtual attendance” at an event (i.e. a baseball game), complete with sights, sounds, images (and even smells), while optionally providing feedback to the event, e.g., broadcasting a user's cheers to the appropriate area in the arena.
An exemplary embodiment of the Personal Handheld Computing Device Presentation System To Interact With Various Projection Devices aims to enable speakers to use their own handheld computing devices (with presentation software and data loaded onto the handheld computing device) in presentations in various places. This is especially ideal for the speaker who needs to travel light and frequently between various presentation sites. By enabling the speaker to use his own handheld computing device, the speaker will be capable of having a comfortable, intimate knowledge of the handheld computing, and thus will not need to be concerned with much else besides the presentation material in preparation. A transmitter attaches to the handheld computing device, interfacing with the communication port, which allows the handheld computing device to communicate with various projection devices through a receiver base. The transmitter and/or the receiver may be owned by either the conference center or the speaker, although it may be more advantageous to the speaker to have his own transmitter-receiver-handheld computing device set, since various implementations of Handheld Computing Devices are available, many with incompatible communication ports.
The personal Handheld Computing Device will contain the presentation software as well as all necessary presentation data files. The user, familiar with his own Handheld Computing Device and presentation software, will have little difficulty preparing to present, even if he or she is at an unfamiliar conference center. After attaching the transmitter to the Handheld Computing Device, the receiver base will receive the video signals from the transmitter and transmit them to the projector unit. The receiver base has interface ports for both sound and video. Once the minimal setup procedures are completed, the speaker can immediately start the presentation—ideal for keeping schedules on target.
A stylus may be provided to operate the touch-activated screen. Optionally, it may have a laser pointer.
These and other embodiments will be described in greater detail with reference to the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the Integrated Information Presentation System with Environmental Controls and the corresponding component parts will now be described in detail, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 illustrates a top view of one exemplary embodiment of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 2 illustrates a back view of one exemplary embodiment of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 3 illustrates a view of the left side of one exemplary embodiment of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 4 shows a view of the right side of one exemplary embodiment of Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 5 shows a view of the front side of one exemplary embodiment of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 6 shows a top view of one exemplary embodiment of the remote control according to this invention;
FIG. 7 shows a top view of one exemplary embodiment of the stylus according to this invention;
FIG. 8 shows a top view of one exemplary arrangement of the Information Display Device System (“PDA-device”) on a pocket computer according to this invention;
FIG. 9 shows a cut-away side view of one exemplary embodiment of the Integrated Presentation Environment Assembly with Controls (“Presentation Booth”) according to this invention;
FIG. 10 shows a front view of one exemplary embodiment of the Integrated Presentation Environment Assembly with Controls (“Presentation Booth”) according to this invention;
FIG. 11 shows an exemplary personal handheld computing device according to this invention;
FIG. 12 shows an alternate exemplary embodiment of the viewable top of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 13 shows an alternate exemplary embodiment of the viewable top of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 14 shows an alternate exemplary embodiment of the viewable top of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 15 shows an alternative exemplary embodiment of the cover of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 16 shows an alternative exemplary embodiment of the viewable top of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 17 shows the relationship of devices of the Integrated Information Presentation Device (“PowerPodium”) with a central processing unit (CPU) according to this invention;
FIG. 18 shows an exemplary embodiment of the viewable top of the Integrated Information Presentation Device (“PowerPodium”) according to this invention;
FIG. 19 shows one exemplary set of steps taken to set up the Integrated Information Presentation Device, with an alternate path but similar set of steps taken to set up the Integrated Presentation Environment Assembly with Controls according to this invention;
DETAILED DESCRIPTION
An exemplary embodiment of the Integrated Information Presentation System With Environmental Controls aims, for example, to alleviate many of the problems associated with making presentations of all types, and making them easier to give and of a higher quality to receive. The Integrated Information Presentation System With Environmental Controls comprises a combination of an Integrated Information Presentation Device (also known as a PowerPodium), an Integrated Presentation Environment Assembly with Controls (also known as a Presentation Booth), a Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices, a stylus, and a remote control. With the Integrated Information Presentation System With Environmental Controls, aspects of a presentation are enhanced, as well as providing the speaker an opportunity to enhance his skill in giving a presentation.
The Integrated Information Presentation Device 1 is generally related to the field of Presentation Devices, and to the field of Computing Devices (commonly called computers). Methods are introduced to control environmental variables, interact with staff and audience, and enhance the ability of speakers to present high quality presentations.
For many years, people who make public or private presentations have contended with multiple devices to control lights, sound, time of presentation, and the slide presentation itself. With the Integrated Information Presentation Device the speaker now will be able to, for example, control, electronically, these—and many other—features, integrated in one manageable package.
The Integrated Information Presentation Device and its associated features are comprised primarily of a casing with a display, hardware controls embedded in it or software controls, various input and output devices, and a processing unit. The Integrated Information Presentation Device is to be located, for example, in or on meeting room podiums or other appropriate platforms to increase the effectiveness of presentations. The base, the PowerPodium Central Unit 56 , of the Integrated Information Presentation Device may also be housed out of sight to allow a less cluttered working area for the speaker. The features of the Integrated Information Presentation Device may be implemented by various combinations of both hardware and software and any combination thereof. The display is visible to the speaker, but may not be to his or her audience. The screen and its features enable the speaker to focus on the speech and audience at hand and eliminate distractions.
With the Integrated Information Presentation Device, these environmental functions may be controlled by the fingertips of the speaker at a time he or she determines appropriate. There are also devices used to interact with facility management in case that immediate help is needed. Software programs, commonly called “Instant Messaging” or E-mail, currently enable two people to send information back and forth. Programs similar to one or both of these can be used to relay information from the audience to the speaker, or more likely, from an assistant to the speaker. There are also similar programs found in cellular telephones and in some text pagers, which may also be utilized as audience interface devices.
In a first exemplary embodiment, encompassing FIGS. 1 through 5 , the Integrated Information Presentation Device with many features installed is described. In particular, the Integrated Information Presentation Device 1 comprises a display 2 , divided into a presentation screen 2 A and a Message Center 2 B, a time of day clock 3 A, a time keeper 3 B, an Internet button 4 A, a presentation button 4 B, a previous slide button 5 A, a next slide button 5 B, lighting controls 6 , window lighting controls 7 , presentation screen controls 8 , sound controls 9 , microphone controls 10 , temperature controls 11 , air flow controls 12 , shortcut mode buttons 13 , black screen button 14 , white screen button 15 , mute button 16 , slide sorter view button 17 , left trackball button 18 A, right trackball button 18 B, trackball 18 C, Assistance Required Button 19 , keyboard 20 , power cord 31 , video out 32 , modem 33 , Ethernet port 34 , mouse port 35 , keyboard port 36 , parallel port 37 , serial port 38 , video interface port 39 , cooling vent 40 , protective cover 41 , protective cover hinge 42 , DVD-ROM drive 43 , 250 MB Zip™ drive 44 , 3.5″ floppy disk drive 45 , media card reader 46 , CD-ROM drive 47 , infrared port 48 , remote control storage compartment 50 , stylus storage compartment 51 , remote control locator button 52 , stylus locator button 53 , detachable presenter unit 55 , and PowerPodium central unit 56 . It is to be appreciated that any peripherals, devices, components, or parts that can be utilized with computing devices may be incorporated with the Integrated Information Presentation Device. Additionally, the term module as used herein can be any hardware, software, or combination thereof, that can be used to perform the functionality associated therewith.
The display 2 , for example, may be any photon-emitting or photon-reflecting device which can be configured to display words or images from a CPU or other computing device. Some embodiments of the display are the cathode-ray tube, the liquid crystal display (LCD), and the plasma display.
A exemplary embodiment of the Integrated Information Presentation Device will enable the speaker the option to separate the Detachable Presenter Unit 55 from the PowerPodium Central Unit 56 . These two units may be kept physically together, or they may be separated to allow an uncluttered presentation area. The Detachable Presenter Unit 55 could contain all hardware integral to control the presentation and the environment as it is given, and optionally a protective cover 41 fastened by a hinge 42 . The PowerPodium Central Unit 56 can have the hardware essential to the processing of presentation software, message center, and other commands, as well as the removable storage interface devices. The connection between the units may be a physical connection (such as, but not limited to, electrical wire, fiber optic cable, or other physical connection energy transmission device), or may be a wireless connection (such as, but not limited to, Infrared, Ultrasound, Radio Wave, or other device capable of transmitting and receiving energy). The PowerPodium Central Unit 56 may have a power cord 31 to be connected to a power source, it may have a self-contained power source, such as, but not limited to a battery, or it may have a connection to the Detachable Presenter Unit 55 and draw power from it. The Detachable Presenter Unit 55 may have a power cord to be connected to a power source, may have a self-contained power source, such as, but not limited to a battery, or may have a connection to the PowerPodium Central Unit 56 and draw power from it. The PowerPodium Central Unit 56 may also have a cooling vent 40 to assist in dissipating heat from the unit.
When using the exemplary Integrated Information Presentation Device, the speaker may prepare a presentation at some external location of his choice, and transfer that presentation to the invention by such means as, but not limited to, a CD-ROM diskette, a floppy (or 3.5″ disk), an Iomega Zip™ disk (or Jaz™ disk), DVD, a flash memory unit, via e-mail, FTP, WI-FI, wirelessly, or the like. One exemplary embodiment of a removable storage reader and writer that provides access for many different storage technologies, for example, is known as the AtechFlash Pro II Media Card Reader which has the capability of reading the following technologies: Compact Flash™, IBM Microdrive™, SmartMedia™, Multimedia™, and Secure Digital™ plus. It also has a front USB port to connect to various other technologies. Of course, as technologies change and advance, new removable storage devices will become available and are easily incorporated into the design of the Integrated Information Presentation Device as warranted. These storage drives may be physically located on any surface of the Integrated Information Presentation Device, and may have retractable or removable covers to prevent damage.
One exemplary feature of the Integrated Information Presentation Device involves the installation of “Agenda File Organizer” software. This software can be activated (or can be auto-activated) to run whenever the speaker inserts a removable medium. The exemplary purpose of this software would be to copy the presentation file (and any other appropriate files) to, for example an internal hard drive or memory for later use, thereby enabling the speaker to “save” his presentation on the particular instance of the Integrated Information Presentation Device he will use, and to keep the removable media elsewhere as a “backup.” This feature would make it possible for a conference organizer to arrange the presentation files in the order they appear on a conference program, and for the presentation files to be opened in an orderly sequence. While some computer users may not need such software, it may be desirable to have this available as an option for those speakers who are not as comfortable manually controlling this process.
Another feature of the Integrated Information Presentation Device is to enable a speaker to make use of what is called “Multiple Monitor” support (“Dual Display,” “Dualview,” etc.) available in some presentation packages. By using this feature, the speaker can view his slides in a format tailored for speakers, including any notes the speaker developed, as well as smaller views of some combination of the current, previous and next slide. The audience will see a second view comprising normally of only the current presentation slide. This second view is actually the view of the “second monitor,” although it may be fed to a projector or a screen suitable for audience viewing (like large plasma screens, for instance). This may be accomplished by such means as, but not limited to, using two video cards or a single dual display video card, for example. One of the output signals is fed to a projector to display the presentation to the audience.
The presentation portion of the Integrated Information Presentation Device, visible normally only to the speaker, commonly referred to as a screen 2 , may display the graphic and textual outputs of one or multiple software programs running on the Integrated Information Presentation Device to enable the speaker to customize the presentation. The software programs include, but are not limited to presentation software, and messaging software. Shortcut buttons (either physical or software implemented) may be provided, for example, to quickly format the screen into any one of a number of desirable configurations. Such formats could be optimized for showing the speaker's notes at maximum size, showing just the slide and the message center, or segmenting the screen to show all available image sources and files. The shortcut buttons interact with the appropriate software and hardware, for example, to segment the presenter's screen, the audience's screen, or both to enable the presenter to make the best use of available tools without cluttering up the view with unnecessary ones. For instance, it may be desirable for the speaker to see the presentation slide, the message center, a live video feed of himself, and a live video feed of a remote speaker or audience who may be participating in the same program. At the same time, he may not want to clutter the audience view with all of those windows, so the audience screen image may be formatted to have only the main slide view and one or more speaker's live image feed. It is envisioned that many possible configurations utilizing many different layouts of both the speaker's screen and the audience's screen are highly desirable, so providing a customizable view for both is a highly desirable feature. Remotely located speakers will be able, for example, through the Integrated Information Presentation Device and peripherals such as, but not limited to, a video camera, to provide audiences with a virtual presentation that can be nearly identical to the experience of those physically present with the speaker. It is also possible to enhance the experience of the audience beyond the remote environment of the speaker. For example, a speaker may be presenting through an instance of an Integrated Presentation Environment Assembly with Controls, configured to transmit the presentation to a remote audience in a large lecture hall twenty feet, one mile, or thousands of miles away, without requiring the presenter to be in a large lecture hall himself or herself. In some cases, such as a sudden absence of a speaker due to illness, a replacement speaker may be enlisted to give a presentation on extremely short notice. The Integrated Information Presentation Device would enable such a speaker to remotely control the presentation as long as some type of connection (Internet, intranet, pots, satellite, etc.) is present to enable commands to be sent. It may be desirable to transfer the presentation files to the speaker's instance of the Integrated Information Presentation Device prior to the presentation time. In the event that such a transfer is impossible or impractical, the presentation may be stored on the instance of the Integrated Information Presentation Device physically present with the audience. In this case, the speaker's view of the slides, notes, and other programs must be transmitted to the speaker's instance of the Integrated Information Presentation Device, and commands sent from the speaker to the instance of the Integrated Information Presentation Device physically present with the audience. Of course, during these times audio devices and other devices used in the presentation can also have their information transmitted.
The presentation software will most likely be a widely used package (although this is not required and custom software may be used) to allow speakers the ease of preparing their own presentations at some previous point.
During the presentation, the speaker controls the advancement of presentation slides using the “Previous Slide Button” 5 A and the “Next Slide Button” 5 B. These buttons will trigger the appropriate software response to bring either the next or previous slide into view on both the speaker's screen and the audience's screen(s).
The message center 2 B may be used to enable an assistant to relay information to the speaker which will help him or her adjust the presentation as it is given to enable customization of the information. Some possible examples of uses of this feature include, but are not limited to, addressing situations as they arise (such as a message that someone's car lights are on), or to remind the speaker not to forget to emphasize a particular point, or to make the speaker aware of any mistakes presented to enable immediate correction. Another use of the message center may be to enable audience members to submit questions to the assistant (before, during, or after the presentation) using electronic means such as, but not limited to e-mail, or other means, such as, but not limited to submitting a hand-written note. The assistant may then filter these questions as appropriate and send them to the speaker using the message center. The message center may be embodied with software such as, but not limited to, “Instant Messenger” technology over the Internet or an intranet, electronic mail protocols, or file transferring from one computer to another.
An exemplary embodiment of the Integrated Information Presentation Device may be embodied with the following feedback devices to enable the speaker to quickly view their status.
Time of Day Clock 3 A—A Time of Day Clock comprises analog and/or digital clocks that display the current time of day. The Time of Day Clock may or may not be integrated with other devices on the Integrated Information Presentation Device.
Time Keeper 3 B—A Time Keeper comprises a timing device which can be set to the time allotted to the speaker to present his material. In the Time Keeper, both an elapsed time and remaining time may be displayed, as well as a visual representation of the percentage of time elapsed, as in a “shrinking bar” format. The Time Keeper may or may not be integrated with other devices on the Integrated Information Presentation Device.
An exemplary embodiment of this invention may include, but is not limited to, different combinations of the following features. The following descriptions refer to FIG. 1 showing one possible embodiment of the device. These controls will involve either the use of wireless communications to send control signals to external devices or the devices may be hardwired.
Lighting Controls 6 —Lighting Controls comprise controls enabling the speaker to customize the lighting of the presentation. The lighting controls may include, but are not limited to, controls to adjust the brightness of lights on the speaker, and controls to adjust the brightness of lights on the audience.
Window Lighting Controls 7 —Window Lighting Controls may house controls for enabling the speaker to control the amount of light entering the presentation room from external sources (for example, the sun). The Window Lighting Controls may include, but are not limited to, a device which triggers a mechanical operation of individual blinds, shades, and/or curtains, a device to control the opacity of liquid crystal glass, or other means to control the blocking of light, either partially or totally. For example, liquid crystal glass is glass that is made with a thin film of liquid crystals such as those commonly found in digital watches so that when an electric current is turned off and on, a corresponding change will take place in the liquid crystals so as to block light (or diffuse it) or allow light to pass through the window. This glass can be used in windows as an alternative to having physical window shades, blinds, or curtains.
Presentation Screen Controls 8 —Presentation Screen Controls comprise controls for raising and lowering one or more projection screens. Also, in general, controls can also govern other types of automated hardware that perform various functions.
Sound Controls 9 —Sound Controls comprise controls for adjusting the balance and volume of the room sound system to produce the desired effect for the presentation listeners.
Microphone Controls 10 —Microphone Controls comprise controls for the purpose of enabling the speaker to adjust the input from various microphones throughout the presentation area. The microphone controls may comprise, but are not limited to, a master control to adjust all microphones at once (such as to turn them all off) and individual microphone controls to enable the speaker to control participation from various points in the presentation area.
Temperature Controls 11 —Temperature Controls comprise controls to enable the speaker to adjust the desired temperature for the presentation or audience area.
Air Flow Controls 12 —Air Flow Controls comprise controls to enable the speaker to turn on devices to increase air circulation, such as, but not limited to, circular fans. The Air Flow Controls may optionally allow for the selection of settings such as high speed, medium speed, low speed, and off.
Pointer control device 18 —A Pointer Control device comprises a control to maneuver the “pointer” on the screen used to select various items. One common embodiment of the pointer control device is known as a “trackball.” A “trackball” would normally comprise a “left trackball button” 18 A, a “right trackball button” 18 B and a “tracking ball” 18 C. Other common embodiments of the pointer control device include, but are not limited to a “mouse,” a touchpad, a trackpad, a joystick, and head-movement tracking devices.
Black Screen Button 14 —A Black Screen Button comprises a control to provide a way for the speaker to easily and quickly black out the screen viewed by the audience, so as to provide a way to find a desired slide or fix an error without allowing the audience to view or be distracted by this process. The black screen button may optionally also activate a feature known as “slide-sorter” view to enable the speaker to quickly find a desired slide.
White Screen Button 15 —A White Screen Button comprises a control to provide a way for the speaker to easily and quickly white out the screen viewed by the audience, so as to provide a way to find a desired slide or fix an error without allowing the audience to view or be distracted by this process. The white screen button may optionally also activate a feature known as “slide-sorter” view to enable the speaker to quickly find a desired slide.
Mute Button 16 —A Mute Button comprises a control to turn off all sound output from the current configuration of the Integrated Information Presentation System With Environmental Controls.
Slide Sorter View Button 17 —A Slide Sorter View Button comprises a control to provide a shortcut to enable the speaker quickly to get to the view that displays a thumbnail view of all slides and enables the speaker to access a specific slide by selecting it. The Slide Sorter View Button will also be set to black out (or white out) the audience screen while this process is going on to minimize distractions to the audience.
Internet Button 4 A—An Internet Button comprises a control to enable the speaker to quickly switch software programs to allow browsing of the Internet. The use of the Internet Button requires a connection to the Internet to be established, either prior to the presentation, or immediately upon request or, lacking this connection, that the desired web pages have been cached or downloaded into volatile or non-volatile memory, available for browsing ‘off-line.’ Optionally, this button may automatically establish the Internet connection as part of its function.
Presentation Button 4 B—A Presentation Button comprises a control to enable the speaker to quickly switch software programs to the presentation software.
Shortcut Mode Buttons 13 —Shortcut Mode Buttons comprise a control to enable saved settings to be used to reset the environment to a previously determined configuration. This previously determined configuration could be a static configuration or a programmable configuration. The shortcut mode buttons configure multiple settings of environmental devices in response to being activated, so that a speaker does not need to adjust each device separately. One of the shortcut buttons, for example, may be set up for providing a general presentation environment. The speaker can then use the various other environmental control buttons to “fine tune” the environment to his or her liking. For another example, one of the shortcut buttons may be set up to turn on all lights to enable the audience to more easily enter and exit the room during intermissions.
Assistance Required Button 19 —also known as the “panic button” or “HELP button” an Assistance Required Button comprises a control to enable the speaker to alert facility staff when immediate assistance is needed for security or technical assistance. The Assistance Required Button is protected from accidental activation, for example, with a cover and raised lip surrounding it. The Assistance Required Button would trigger a response by the Integrated Information Presentation Device to notify the appropriate people that immediate assistance is needed in the conference room. The Assistance Required Button may be alternatively configured as a toggle switch, such that the signal is continuously sent until the speaker deactivates it, presumably when help has arrived.
The Integrated Information Presentation Device may also include, but is not limited to, the following interface devices.
Video Out 32 —a Video Out port comprises a port used to send the video signal of the audience presentation image to an external video image display unit, for example, a projector. The image defined by this signal may be identical to the image the speaker sees on the main display, or more likely, it will be an image of only the presentation elements to be viewed by the audience as transmitted by the presentation software.
Modem 33 —a Modem interface comprises a port used to connect the invention to an external computing device, most likely a computing device used as an entry node or gateway to the Internet, using a plain-old telephone system line (POTS line). The modem may also be used to link to the Internet using a higher speed line such as, but not limited to, a Digital Subscriber Line (DSL), a Cable Modem line, or an Integrated Services Digital Network line (ISDN), for example (additional hardware may be necessary in some cases; not all services are available in all areas).
Internal Telephone Instrument—an Internal Telephone Instrument comprises a device which can be set up to enable the speaker to communicate by telephone before, during, or after the presentation from the presentation site, specifically, from the Integrated Information Presentation Device. The Internal Telephone Instrument may be connected through a wireless connection, or through a physical wire. As there are programs to enable a computer to use the modem line for this purpose, there may not be a need to have both a modem line and a phone line, although it may be useful to some speakers if they want to be connected by phone to someone off site, while they are browsing on the Internet. Alternatively, a “private line” may be set up which connects internally to the audio visual department, either directly or by use of an extension. The telephone instrument may be able to operate as a speakerphone. Alternatively, an external jack may be installed in the Integrated Information Presentation Device to enable a speaker to connect his own phone to the line, whether to allow some privacy on the call or to enable communication even if the speakerphone is not in perfect working order.
Ethernet Port 34 —an Ethernet port comprises a port used to connect the invention to a local area network (LAN) within the building/company, and thus access to a server, the company intranet, or the Internet. Frequently, there is a server computer and/or a firewall before the LAN connects to the Internet (or WAN—wide area network). The connector for the Ethernet port looks very similar to the connector on a phone line, but is slightly larger.
Mouse—a mouse is one common embodiment of a pointing device which enables the user to control a pointer on the screen and initiate various actions using the buttons on the mouse (commonly two). The mouse is commonly connected using a PS/2 port (also known as a “Mouse port”) 35 , a serial port, or a USB port. The mouse can be, for example, mechanical (a type of mouse with a hard, rubber-coated ball which moves mechanical sensors as one moves the mouse over a surface), opto-mechanical (Same as mechanical, but uses optical sensors to detect the motion of the ball), or optical (no moving parts, but uses a light-emitting diode or similar electronic part and a sensor to detect motion over a surface) and they can be cordless or connect with a cord.
Keyboard 20 —a keyboard is a common embodiment of an alphanumeric input device which enables the user to send commands or strings of characters represented by a combination of digital bits (called bytes), which cause the current software to respond with some function, or to record the intended character, most commonly using ASCII codes (but may also be Unicode or EBCDIC (no longer widely used)). The keyboard may be desired to interface with the operating system or application software during set-up and may be detached during the presentation, although this may not be required. A storage container, for instance a drawer, may be housed in either the invention body, or in the podium, to enable the keyboard to be out of view and out of the way during the presentation. The keyboard may be wireless (using an internal or external wireless keyboard port), or it may have a physical connection (a keyboard port 36 ).
In addition to the ports to interface to the above devices, this invention may also include, but is not limited to, any combination of the following interface ports. These ports can be used to connect to a specialized device or new devices as they become available on the marketplace.
Parallel Port 37 —A parallel port is a type of interface port that transmits digital data over eight pins in groups of eight bits (one bit on each pin) simultaneously. There are other pins used in the parallel port to send information about the data, and to enable communication between the device and the peripheral. A common peripheral that uses the parallel port is a printer.
Serial Port 38 —A serial port is a type of interface port that transmits digital data one bit at a time over one pin. Other pins are used to send information about the data and to enable communication between the device and the peripheral. Serial ports are slower than Parallel ports, and may be phased out by USB ports.
Video Interface Port 39 —A video interface port is an interface port for video displays, monitors, and graphical output devices. In an exemplary embodiment of the Integrated Information Presentation Device, the video interface port is connected to either a second video card, or to a video card with two output ports. In another embodiment of the Integrated Information Presentation Device, the port may be simulated by a signal splitting or signal duplicating device. In this latter instance, however, some of the robust features associated with the presenter's view as opposed to the audience's view would not be possible, since splitting or duplicating the signal produces identical images for both the presenter and audience. The video interface port transmits a second video signal to an external monitor, for example, a projector.
Infrared Port 48 —An infrared port comprises a device which can detect and decode signals in the infrared range of the electromagnetic spectrum, and optionally transmit electromagnetic signals in the infrared range. The infrared port may be used to receive signals from a device such as, but not limited to, a remote equipped with an infrared transmitter, or the infrared port may be used to send output to a device such as, but not limited to, a printer. In some embodiments it is advantageous to have multiple the infrared ports, depending on the actual design and purpose of the embodiment of the invention. Some of the infrared ports may be used to send instructions to various external devices which control environmental variables.
RF Transceiver Port—An RF transceiver port (sometimes known as just an RF Transceiver) comprises a device which can transmit to and receive signals from various devices that control the environment. It may be appropriate to have multiple RF Transceiver ports, depending on the actual design of the embodiment of the Integrated Information Presentation Device.
An exemplary embodiment of the Integrated Information Presentation Device may include, but is not limited to, any, a combination of, or all of the following removable storage devices.
Read/Writeable DVD Drive 43 —A Read/Writeable DVD (Digital Video Disc) Drive is a device which is used to read digital signals from or write digital signals to a disc properly formatted for such uses.
Zip™ Drive 44 —a Zip™ Drive is a device that provides a large amount of digital data storage on a diskette that is not much bigger than a standard 3.5″ Floppy disk. The 250 MB Iomega Zip™ Drive is compatible with older 100 MB Zip™ Drive Cartridges. Iomega also manufactures a larger Jaz™ drive, whose disks hold either 1 GB (older) or 2 GB of data.
3.5″ Floppy Disk Drive 45 —a device used to read magnetic diskettes capable of up to 1.44 Megabytes of digital data storage
Media Card Reader 46 —a device that reads multiple formats of removable storage. One such instance of the Media Card Reader fits into a 3.5″ floppy disk drive bay and reads/writes the following types of media cards: Compact Flash™, IBM Microdrive™, SmartMedia™, Multimedia™, and Secure Digital™ plus. The instance of the media card reader also has a front USB Port to enable the connection of various other removable storage devices. If another instance of a media card reader is used that is not equipped with a USB Port, a separate USB port should be added to the device.
Read/Writeable CD-ROM Drive 47 —“Compact Disc” Read Only Memory. A Read/Writeable CD-ROM (Compact Disk Read Only Memory) Drive is a device which is used to read digital signals from or write digital signals to a disk properly formatted for such uses.
The Integrated Information Presentation Device may also include, but is not limited to, any or all of the following external components and their storage compartments
Remote Control 22 —The Integrated Information Presentation Device may also have a remote control, which enables the speaker to move freely from the Integrated Information Presentation Device throughout the room. An exemplary remote control 22 is shown in FIG. 6 comprising a pointer activation button 60 A, pointer lens 60 B, lighting controls 61 , previous slide button 62 A, next slide button 62 B, sound controls 63 , microphone controls 64 , Internet button 65 A, presentation screen button 65 B, time of day display 66 A, presentation time elapsed 66 B, and presentation time remaining 66 C.
A pointing device similar to what is commonly known as a “laser pointer” may be incorporated into the remote control so that as the speaker moves about the room, he or she can point to various parts of the image using the remote. The remote control will most likely be battery operated, although this is not a necessity (with the understanding that wires may hinder the mobility of the speaker). The commands from the remote control may be processed through the Integrated Information Presentation Device, and then distributed to any appropriate external devices through a single set of transmitters. Alternatively, the commands may be sent directly from the remote control to the appropriate external devices, the alternate remote actually comprising a conglomeration of remotes.
The remote control may be housed in the Remote Control Storage Compartment 50 when not in use. The Integrated Information Presentation Device may give the user a warning message and/or sound a warning bell if the Integrated Information Presentation Device is shut down without the remote control being in the Remote Control Storage Compartment. This will aid in preventing the accidental misplacement of the remote control between speakers, especially if the assistants breaking down the room are not aware of all the features/components of the Integrated Information Presentation Device. Likewise, a Stylus Storage Compartment 51 optionally ensures that the stylus 53 is kept with the unit. The Remote Control Storage Compartment and Stylus Storage Compartment may also comprise, but are not limited to, components to enable the recharging of batteries in the remote control or the stylus while it is being stored, a locking mechanism to hold the remote control or the stylus firmly in place, and a protective cover. Next to each storage compartment, optionally, a button to “locate” the remote control 52 or to locate the stylus 53 , which may be pressed if it is misplaced. This button may trigger a process to sound an audible and/or show a visual alert to enable the missing remote control 52 or the missing stylus 53 to be tracked down, similar to devices found in some portable telephone handsets and television remotes. The alert may sound/flash for a specified time, or it may continue until a button is pressed on the remote control or the stylus once it has been found.
As an alternative (or as an addition) to the remote control, another solution is to enable people to use their own handheld computing devices, also called personal digital assistants (PDAs—Pocket PCs, Palm Pilots, etc.) 75 , to control their presentations. See FIG. 8 . Currently, there is no standard for the port to attach accessories to differing types of handheld computing devices, so to enable multiple versions of handheld computing devices to be used, multiple transmitters with the appropriate connectors must be included with the Integrated Information Presentation Device (Unless the Integrated Information Presentation Device is tied to a specific type of handheld computing device). Software can be distributed to speakers which would enable them to use their own handheld computing devices to control the functions of the Integrated Information Presentation Device. A transmitter 76 can be provided to the speaker by the conference center that would enable the output of the software program running on the handheld computing device (commands to carry out) to be transmitted to the Integrated Information Presentation Device. The transmitter may be particular to one particular instance of the Integrated Information Presentation Device (or may be reprogrammed each time if possible), used by the speaker only during his or her setup, rehearsal, and presentation. One major advantage of this would be that speakers could use their own handheld computing devices and software to control the presentations in any conference center that has an Integrated Information Presentation Device. The software on the handheld computer may control only basic functions, or it may duplicate every function of the Integrated Information Presentation Device. Although presentation screen data can be transmitted to the Integrated Information Presentation Device, it is more likely that the presentation would be pre-loaded on the Integrated Information Presentation Device and the handheld computer—only the commands need to be transmitted from the handheld computer to the Integrated Information Presentation Device. A stylus 24 is optionally provided that could be used in conjunction with handheld computing devices that would function both as an input to the touch screen of the handheld computing device, as well as a laser pointer device for calling attention to images on the audience screen. For example, the stylus may be equipped with the input device at one of its ends, and the laser pointer at the other.
Additionally, if transmitters were distributed to members of the audience to use on their own handheld devices, or if handheld devices were available at the beginning of a session for audience use, this would enable the audience to interact with the speaker before, during, or after his presentation. Cell phones, two-way pagers, and other similar devices capable of transmitting text messages may also be utilized if the signal is routed to the Integrated Information Presentation Device using for example, email over voice or data lines, text messaging, or other means.
Stylus FIG. 7 , # 24 —Optionally, a stylus enables the speaker to interact with the presentation screen, enabling notes to be “written” on the slides during the presentation. One possible embodiment of the stylus, a “dumb stylus,” is used to provide only pressure or presence on a pressure sensitive or field feedback screen. Another possible embodiment of the stylus 24 , a “smart stylus,” “reads” the part of the presentation screen it is tracing through an electromagnetic sensing tip 67 and transmits this information back to the main device for processing. An imbedded laser pointer 70 may be embedded in the other end of either embodiment of the stylus 24 and activated by one of two optional activation features—the embedded laser pointer 70 being activated or deactivated by the rotating of one end 69 B of the stylus 24 about the rotational switch 69 A, or a switch activated by the pressing of the clothing clip 68 on the side of the stylus 24 .
A second exemplary embodiment, an extremely minimal view of available features, of the top view of the Integrated Information Presentation Device will now be described as shown in FIG. 12 . In this exemplary embodiment, the viewable top surface of the Integrated Information Presentation Device comprises a viewable screen 2 , slide navigation buttons 5 A and 5 B, and an embedded trackball 18 A, 18 B, and 18 C. With this embodiment, the speaker would be able to load the presentation files, activate various programs using the trackball, and navigate the slides during the presentation using the previous slide button 5 A and the next slide 5 B. Alternatively, the trackball may be omitted and a mouse or other pointing device could be used to select programs. This embodiment would be ideal for situations where the environment is not controllable (i.e. outdoor presentations, private home sales presentations, etc), or where the frequency of presentations is such that a highly functional (and therefore presumably more expensive) device is not warranted (i.e. some classroom situations, independent contractor going to homes to secure bids, etc).
A third exemplary embodiment, another possible configuration of the Integrated Information Presentation Device, will now be described as shown in FIG. 13 . In this embodiment, the viewable top surface of the device comprises a viewable screen 2 , time management instruments 3 A and 3 B, buttons to alternate between an Internet connection 4 A and the presentation information 4 B, slide navigation buttons 5 A and 5 B, an embedded trackball 18 A, 18 B, and 18 C, Black Screen Button 14 , White Screen Button 15 , Mute Button 16 , and a Slide Sorter View Mode Button 17 . In this embodiment, the viewable screen 2 is divided between a live-feed image of the speaker 2 C, the speaker's notes and slides 2 A, and the message center 2 B. The live-feed image of the speaker may be used in cases where the audience is so large that the speaker's image is also projected on a screen, or presented on a large viewable screen similar to those found in many professional sport stadiums, or where a “web-cast” or other broadcast of the presentation is being made. This configuration of the viewable screen 2 provides the speaker visual feedback as to his positioning, lighting, and movements during the presentations. This configuration may be utilized in cases where the presentation will be recorded and distributed at a later date.
A fourth exemplary embodiment, a possible minimal view from a professional speaker's point of view, of the Integrated Information Presentation Device will now be described as shown in FIG. 14 . In this embodiment, the viewable top surface of the device comprises a viewable screen 2 , buttons to alternate between an Internet connection 4 A and the presentation information 4 B, slide navigation buttons 5 A and 5 B, an embedded trackball 18 A, 18 B, and 18 C, and some combination of environmental controls 90 . The environmental controls are customized to be appropriate for whatever room(s) the device will be used in. This embodiment would enable a speaker to have some control over the environment (sound, lights, physical screen, etc), while not requiring that the hosting site give up all control of the environment to the speaker. Alternatively, certain functional controls can be installed but not enabled at any one time. A physical switch, or a software disablement of the control, may prevent a speaker from changing any one or group of environmental controls when the hosting site determines that speaker control over an environmental variable is not desired (for example, allowing the heater to be activated during summer months, allowing any equipment to be activated while undergoing repairs).
A fifth exemplary embodiment, shown in FIGS. 15 and 16 , shows another possible configuration of the Integrated Information Presentation Device 1 . In FIG. 15 showing the front view of this configuration, the screen is embedded in the cover of the Integrated Information Presentation Device, not unlike laptop configurations. This allows larger buttons, more buttons, or even the keyboard layout to be included on the viewable top surface of the Integrated Information Presentation Device. This particular embodiment of the Integrated Information Presentation Device shows the unit as an inseparable unit, in which the processor, removable storage units, interface cables/connections, and the speaker's functions are contained in one physical unit. This configuration is desirable in situations in which equipment is moved extremely frequently, or where inexperienced speakers or technicians must frequently set up the Integrated Information Presentation Device. The screen 2 (whether touch-sensitive or passive) in this embodiment may be configured to have a live-feed image of the speaker 2 C, the speaker's notes and slides 2 A, and the message center 2 B. In this fifth embodiment, the viewable top surface of the Integrated Information Presentation Device is shown in FIG. 16 . In this configuration, the buttons on the viewable top surface of the Integrated information Presentation Device are enlarged, for example, for visually impaired speakers, or multi-lingual labels for buttons. Alternatively, many buttons could be added to enable control of more devices throughout the speaker's environment, or throughout the environments of any audience viewing the presentation over an Internet or other connection. For example, one set of buttons control a remote environment for an audience in New York City, while another set controls the environment where you are, say Los Angeles. The same or different Internet or other data connection that is used to send the speaker image could be used to send commands from one the Integrated Information Presentation Device to the other. Also, this configuration could enable the keyboard to be included in the top surface of the device, rather than as a removable device. This feature is desirable in situations in which the Integrated Information Presentation Device is used to input speaker presentation information directly into the Integrated Information Presentation Device or in situations in which the Integrated Information Presentation Device is used to access many web pages where text input is necessary. This configuration is also desirable in situations where the Integrated Information Presentation Device is highly portable, so that there are fewer components of which to keep track.
A sixth exemplary embodiment of the Integrated Information Presentation Device would enable the display of data or images transmitted to and/or from meeting participants at remote locations via devices such as, for example, whiteboards, scanners, and printers. This embodiment would also enable participants supplied with appropriate technology to have notes, diagrams, or images they produce before or during discussions to be viewed by the speaker immediately in a remote location. This embodiment would enable any other participant at any location involved in the conference to view notes, diagrams, and drawings in real time. This embodiment enables a speaker or participant to address any particular topic or answer a particular audience question and transmit not just his or her voice or video image, but any representations drawn on the board. This embodiment also enables any such sketches, diagrams, and text to be captured to be included in any transcripts, guides, or summaries of the presentation or conference. This can be accomplished numerous ways, from using a video camera to capture the board (and speaker) image to using a marker-tracking device to electronically track the color and positioning of markers as they mark on the board (sometimes called an Electronic Whiteboard). This embodiment enables a speaker or conference to use multiple whiteboards and the accompanying software to enable unique interactions, such as multiple speakers (and audiences) in various locations working together to solve a problem (sometimes also known as video conferencing), define a solution, or provide diagrams or explanations to complement what is being presented. An alternative embodiment provides a way for audience members (probably in more intimate settings, but not necessarily) to interact with an image, or even electronically “point” to a particular place on the display, if the capability to interact with handheld devices is available, through such means as, but not limited to, the Internet, an intranet, or wireless signal. As has been described in other embodiments, the speaker at the Integrated Information Presentation Device is able to control how and when these images and data are displayed on the speaker screen and the audience screen(s).
It is also understood that as other imaging technologies and transmission means become widely available that the Integrated Information Presentation Device could accommodate many of these quite easily.
A seventh exemplary embodiment FIG. 17 of the Integrated Information Presentation Device 300 is presented. Comprising the seventh exemplary embodiment are the processing unit (CPU) 302 , main display 304 , secondary display 306 , receiver 308 , transmitters 310 , internal RAM/ROM 312 , Internal Long-term storage 314 , Removable Long-term storage 316 , pointing device 318 , keyboard 320 , navigation buttons 322 , mode buttons 324 , power supply 326 , and clock 328 . The processing unit receives inputs from the various devices, processes them, and produces signals to the appropriate output device.
The main display 304 would normally correspond to the display 2 of the Integrated Information Presentation Device, but not in every case, while the secondary display 306 may be, for example, a projector, a second screen on the Integrated Information Presentation Device, a separate screen on the wall, or even a screen thousands of miles away able to receive the output of the Integrated Information Presentation Device. The receiver 308 may be comprised of any device or set of devices capable of detecting electromagnetic radiation, whether through an electromagnetic conductor or a wireless signal, and converting it into data for the purpose of getting feedback or data from external devices. The transmitters 310 may be comprised of any device or set of devices capable of transmitting electromagnetic radiation, whether through an electromagnetic conductor or wireless signal for the purpose of sending commands or data to external devices.
The Internal RAM/ROM 312 would normally correspond to volatile memory chips, although it may correspond to non-volatile memory in some instances. The Internal Long-term storage 314 comprising for example, a hard drive, would be used for example, to store the presentation software and the agenda file organizer software. In contrast, the Removable long-term storage 316 comprising for example, a CD-ROM, would be used to load the specific presentation of various speakers to prepare for instance, for a conference.
The pointing device 318 comprising for example a mouse, a trackball, a lightpen, or head movement detector gives control over the cursor to allow the user to interface with graphical user interfaces (GUI's). The keyboard 320 allows alphanumeric data to be sent for processing by the processing unit (CPU) 302 , used for example, to enter data about the speakers on a daily agenda or presentation data. The navigation buttons 322 comprise buttons which control the cursor, buttons which signal to execute a task such as advancing to the next slide, or buttons that are used to select appropriate files from a directory listing. The mode buttons 324 comprise for example, environmental adjustment buttons (for example lighting, temperature, air flow, etc.), shortcut mode buttons, Internet button, presentation button, black screen button, white screen button, and assistance required button. The power supply comprises a means for transmitting electrical energy from an energy source, such as, but not limited to, a battery, a wall outlet, a generator, or a solar panel, to the processing unit 302 through an electrical conducting material.
It is to be noted that as technology progresses, new interface, output, processing, computing devices, and input devices will be developed. The specific choices for hardware may be updated to reflect development in these areas.
While there are numerous valid combinations of steps to set up the Integrated Information Presentation Device to be used to give a presentation, the following is a list of some of the steps a presenter might follow in the use of the Integrated Information Presentation Device to facilitate a presentation. These exemplary steps are illustrated in FIG. 19 , attached.
1. Turn on the Integrated Information Presentation Device. Using telephone connection to audiovisual technical staff review preparations for presentation. 2. Insert media with presentation files into storage media device (CD, diskette, flash card, memory stick, etc.), using the Integrated Information Presentation Device's Agenda File Organizer software. Presentation file may have been edited prior to presentation utilizing Presentation Booth. 3. Open presentation file, check slides. 4. Adjust sizing of notes window as desired 5. Adjust room environment controls (e.g. lighting, blinds, AC/heat, sound) 6. Adjust clock and set timer for presentation. 7. Verify message center connection is working properly 8. Check, Internet connectivity and adjust accordingly, verify connection of any remote locations to the Integrated Information Presentation Device. Contributing presenters may participate using one or more presentation booths remotely connected to the Integrated Information Presentation Device. 9. Scroll through presentation file to desired starting point. 10. At designated time, begin presentation.
In addition, there are numerous valid combinations of steps to set up the Integrated Presentation Environment Assembly with Controls that can be utilized. The following is a list of some of the exemplary steps a presenter might follow in the use of the Integrated Presentation Environment Assembly with Controls. These steps are illustrated in FIG. 19 , attached.
1A. Power up the Integrated Presentation Environment Assembly with Controls 1. Turn on the Integrated Information Presentation Device. Using telephone connection to audiovisual technical staff review preparations for presentation. 2. Insert presentation storage media device (CD, diskette, flash card, memory stick, etc.), using the Integrated Information Presentation Device's Agenda File Organizer software. 3. Open presentation, check slides. 4. Adjust sizing of notes window as desired 5A. Adjust the environment controls of the Integrated Presentation Environment Assembly with Controls (lighting, blinds, AC/heat, sound) 6. Adjust clock and set timer for presentation. 7. Verify message center connection is working properly 8. Check Internet connectivity and adjust accordingly, verify connection of any remote locations to the Integrated Information Presentation Device. 9. Scroll through presentation to desired starting point. 9A. Set recording mode and insert recording media as appropriate 10. At designated time, begin presentation. 11. After review and playback, send to appropriate storage media, and/or facility storage drive/server, and other devices by via Internet, wireless or other means.
The Integrated Presentation Environment Assembly with Controls is related to the field of Training Devices, Presentation Devices, and to the field of Computing Devices (commonly called computers). Exemplary systems and methods are discussed that provide a simulated environment, provide for the taping of the session, and enhance the ability of speakers to present high quality presentations.
An exemplary embodiment of the Integrated Presentation Environment Assembly with Controls solves a number of problems speakers presently encounter in meeting facilities.
One exemplary implementation of the Integrated Presentation Environment Assembly with Controls is seen in FIGS. 9 and 10 . FIG. 9 is a “cut-away” side view showing a speaker during a practice session. The speaker may stand during the session or may sit on a chair (such as, but not limited to, a “bar-stool” chair). To activate the unit, a main power switch 108 is switched on to power the screen 104 , the camera 102 , and the PowerPodium device 1 (and video recording/playback unit 106 , if applicable). Lighting from the ceiling of the Integrated Presentation Environment Assembly with Controls illuminates the PowerPodium. The Integrated Presentation Environment Assembly with Controls may have, for example, a door or a curtain which can be shut/drawn to shield the speaker from external noise and light, or it may be an open unit if it is located in a low-traffic area. A set of headphones, other listening device, or other sound-retarding device may be given to the speaker in high-traffic areas to enable better concentration. If an enclosed unit is used, airflow regulators may be used to keep the environment suitable for use.
Another exemplary implementation of the Integrated Presentation Environment Assembly with Controls comprising the Integrated Information Presentation Device and the Integrated Presentation Environment Assembly with Controls. The Integrated Presentation Environment Assembly with Controls would act similarly to a docking station commonly used with laptops, with the Integrated Information Presentation Device interfacing with it. The Integrated Presentation Environment Assembly with Controls may have various actual environmental controls and/or the means to simulate various environmental controls, with all the appropriate connections to simulate and control the entire presentation area, or it may have a minimal number of connections (video out, etc). Because the Integrated Information Presentation Device is removable in this and similar embodiments, the same physical device could be used both in the Integrated Presentation Environment Assembly with Controls and in the presentation room.
When the Integrated Presentation Environment Assembly with Controls is installed at a location, a technician or facility employee is able take a picture of each of the available presentation rooms for use in the Integrated Presentation Environment Assembly with Controls. The pictures can be taken with a full audience if convenient, or it can be of the empty rooms. Minimally, a printout or developed shot can be mounted opposite the speaker in the Integrated Presentation Environment Assembly With Controls. In an alternative embodiment of the Integrated Presentation Environment Assembly with Controls, an Audience Simulation Display 104 such as, but not limited to, a video screen, capable of displaying an image, is used to display a static picture of an environment, with or without an audience, that approximates the atmosphere of the room the speaker will be using, for example, a generic classroom or auditorium. In a slightly more sophisticated setup, with a screen 104 capable of displaying visual images, a digitized static picture of the available rooms, with or without an audience, taken by a technician or facility employee the presenter can be displayed on the screen. This will enable the speaker to choose a setting that most closely matches the location of his or her presentation to provide a more authentic atmosphere. A technician may load an array of appropriate pictures in the display apparatus for selection by the speaker. Thus, when the speaker looks forward in the Integrated Presentation Environment Assembly with Controls, he or she will see a simulated audience (or at least the arrangement of seats). This feature may be enhanced in by having a video of a real audience (as opposed to a still picture) in a generic room or an actual facility room, or even an interactive audience (this may necessitate another software program to be loaded, not unlike some interactive video games) to provide as realistic an experience is possible. It is appreciated that as technology continues to advance, the simulated audience can continue to be more sophisticated, for example, a full audience with each member having different personalities, preferences, and backgrounds. When used to train speakers, an advanced simulated audience could have various scenarios ranging from ‘pleasant’ to ‘disaster,’ allowing the speaker to think through situations well before facing them in front of a live audience.
Once the Integrated Presentation Environment Assembly with Controls is activated and the speaker adjusts his seating and any materials he needs, the speaker will load his presentation file into the Integrated Information Presentation Device (Alternatively, the speaker's presentation may be already loaded into the Integrated Information Presentation Device by the site technician. If not, the speaker will need to load the presentation using one of the various removable media devices and software programs provided.). If the speaker desires to video tape this practice session, the Video Recording Unit 102 (for example, a Video Camera) can be started and the presentation can commence. During the practice presentation, the speaker can control the paging of slides in the same manner he would control them during the real presentation. Various combinations of features can be “activated” in a particular implementation of the Integrated Presentation Environment Assembly with Controls (also known as a Presentation Booth) at the time of purchase, or perhaps in an upgrade later on. The integrated environmental controls, which are integrated into the circuitry of the Integrated Presentation Environment Assembly with Controls, simulate (as much as can be simulated in a phone booth sized space) the control of the presentation environment. With an interactive Audience Simulation Display, you can control the “virtual lights,” the “virtual shades,” audience microphones, and speaker controls, just as you would in the presentation room. The messages the speaker might receive from an assistant during the presentation through the message center can be simulated through software, though the speaker would see no difference on the Integrated Information Presentation Device. The speaker could also practice using the remote control or any of the other peripheral devices as well.
Other uses of this invention include testing and training speakers while at seminars, classes, or forums on speaking, and providing a compact environment to record presentations on tape or transmit presentations over the Internet in situations where the speaker does not have an audience physically present with him. Multiple instances of the Integrated Presentation Environment Assembly with Controls may be used in a currently under-utilized area in the building (like a small basement room), enabling the facility to offer more features to their customers and better utilize their existing building space.
The exemplary Integrated Presentation Environment Assembly with Controls 100 may include, but is not limited to, the following elements:
A compartment 106 of adequate size, optionally with dimensions equal to a standard phone booth, or 1½ times the size of a phone booth. The compartment may be enclosed, partially enclosed, or open, and it may have doors, curtains or other means to provide more privacy or sound deadening. The compartment may have limited structural walls, similar to some models of payphones with limited privacy. Minimally, the compartment may be nothing more than an area next to the Integrated Information Presentation Device, video camera, and Audience Simulation display mounted on a wall or even a movable partition.
A main power switch 108 which turns on all electronic equipment in the Integrated Presentation Environment Assembly with Controls.
A Video camera 102 , which may focus on bead and shoulders only, zoom in for a close-up view of the speaker's face, or may provide a wide-angle view of the speaker. It is to be understood that as advances are made in image recording technology, they are easily incorporated herein.
An audience simulation display 104 , comprising a static picture, a video display unit, or an advanced image display. It is to be understood that as advances are made in display technology, they are easily incorporated herein.
The Integrated Information Presentation Device 1 , mounted in a podium, on a shelf, or other means of support, resting on a podium, shelf, or other means of support, or supported by other means which allow proper usage of the device.
A video recorder or video playback unit 106 , comprising a device similar to what is commonly known as a VCR (Video Cassette Recorder). The video playback unit may be used in conjunction with the video camera to record the presentation, or it may be used to play a previously recorded presentation.
Various real and simulated environmental controls to simulate the presentation room environment as closely as possible. The environmental controls include, but are not limited to, lighting, temperature, air flow, sound, and any, all, or none of these may be simulated instead of actual.
Thus an exemplary Integrated Presentation Environment Assembly with Controls 100 would have a working PowerPodium device 1 , video camera 102 , a display 104 , Video Playback Unit 106 , and a main power switch 108 .
The speaker can utilize the Integrated Presentation Environment Assembly with Controls sitting down or standing, as in FIG. 11 .
The speaker may have various levels of control over the simulated presentation environment and audience. This level of control may range from choices of static pictures of audience settings (classrooms, conferences, etc.), to fully simulated audiences with individual simulated people being controlled by using artificial intelligence simulation programs or algorithms. The Integrated Presentation Environment Assembly with Controls may also be integrated in such a way as to enable the environmental controls of the Integrated Information Presentation Device to interface with similar devices within the Integrated Presentation Environment Assembly with Controls (lights, air flow, etc) to provide a realistic experience for the speaker.
A video recording/playback unit 106 , such as, but not limited to a VCR (Video Cassette Recorder), is accessible to the speaker for recording a practice session using the camera 102 . This device may be unnecessary if the camera directly holds the recording tape. It may be desirable to have this unit since many cameras use different size tapes than many playback units commonly use. This unit could also be used to give immediate feedback to the speaker, although if demand for the Integrated Presentation Environment Assembly with Controls is high (or the cost per hour is high), the speaker may desire to take the video cassette to another video playback unit, such as in his hotel room. Depending upon the hotel's technological capabilities, the video may be made available to the speaker and/or others the speaker or conference may designate via the Internet or the hotel's internal network, to which the VCR may be connected.
An exemplary embodiment of the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices with many features is described. In particular, the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices comprises a transmitter 201 , shown connected to a generic handheld computing device 200 in FIG. 11 , a receiver base 202 , and software is described.
An exemplary embodiment of the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices is shown in FIG. 11 . In this figure, the speaker's Handheld Computing Device 200 is shown attached to the transmitter 201 . The receiver base 202 is physically separate from the transmitter 201 , which provides mobility to the speaker. While the transmitter 201 could be connected to the receiver base 202 through a long cable, it is more desirable to use wireless technology for communication. The Handheld Computing Device 200 may be the speaker's personal property or the property of the speaker's employer (although it need not be so, if the conference center provides a way to load his presentation on it), and since many handheld computing devices currently have incompatible interface ports, it may also be desirable for the speaker to own his or her own transmitter. This need not be mandatory, if the conference center either chooses a standard transmitter, or if it provides multiple types of transmitters. Handheld Computing Devices (a.k.a. Palm-tops, PDA's, Pocket Computers, etc.) are becoming increasingly more popular, especially as more useful programs are written for them. These devices are often used by business people to keep track of a list of contacts, a schedule of appointments, and e-mail. Since it is becoming increasingly common for traveling business people to have such devices, personalized to their liking, this new functionality would leverage the previous investment in Handheld Computing Devices. By enabling speakers to come to a site with a small package consisting of a Handheld Computing Device, a receiver base, and removable media containing presentation files, the burden of packing larger and more numerous devices is reduced greatly. If a speaker uses his or her own handheld computing device to present information, there is little or no training time, even if the facility has never been visited before.
The software portion of the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices will have various implementations to enable compatibility with popular handheld computing device operating systems, such as, but not limited to, Palm OS™ and Windows CE™. The software running on the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices will communicate with the external receiver base 202 by means of an electromagnetic transmission connection (the transmitter 201 ), such as, but not limited to, an RF connection, infrared port, or even a physical wire. Because of the mobility it gives the speaker, a wireless connection is more desirable.
The external receiver base 202 will receive the signal from the Handheld Computing Device 200 and transmit it to the projection device to be displayed to the audience. If electromagnetic radiation (such as radio waves) is used, care must be taken to ensure that one instance of the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices used in one presentation room does not interfere with another instance of the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices in the vicinity. This situation is avoided, for instance, by using varying frequencies or “activation strings” at the beginning of messages, among other techniques. If the receiver base 202 is owned by the conference facility, it is desirable for it to have the capability of selecting various frequencies to receive, thus giving more flexibility to those speakers who bring their own transmitters.
The use of the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices will enable a speaker to, for example, utilize the “primary” functions (i.e. speaker notes, current slide thumbnail, next slide thumbnail, slide sorter view, etc) of the Integrated Information Presentation Device (PowerPodium) on systems which do not have the Integrated Information Presentation Device installed. The Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices will also be preferred in situations in which the infrequency of presentations, small audience size, or limited budget makes purchasing a full Integrated Information Presentation System With Environmental Controls or even the Integrated Information Presentation Device impractical.
Navigation during the presentation is accomplished by means of a stylus 24 upon the touch-screen of the handheld computing device 200 . The stylus included with most Handheld Computing Devices may be used, if supplied; however, the stylus provided with the Integrated Information Presentation Device or Integrated Information Presentation System With Environmental Controls would be more advantageous to a speaker since it is equipped at one of its ends with a laser pointer.
Another exemplary embodiment of this device comprises pre-loading the presentation software and possibly the presentation data, on the receiver base 202 or even the projection unit. In this embodiment, the signals between the transmitter 201 and the receiver base 202 may comprise, for instance, navigation commands and commands to display, hide, select or move various items/slides during the presentation. This requires, despite any differences between them, the data and presentation software on both devices to be similar enough in appearance and function, or at least to use a common protocol, to enable the speaker to effectively communicate his presentation to the audience.
Optionally, a stylus FIG. 7 , # 24 enables the speaker to interact with the presentation screen, enabling, for example, notes to be “written” on the slides during the presentation. One possible embodiment of this device is a “dumb stylus,” which is used on a pressure sensitive or field feedback screen. Another embodiment is a “smart stylus” 67 which “reads” the part of the screen it is tracing and transmits this information back to either the receiver base 202 or handheld computing device through the transmitter for processing. A laser pointer device 70 may be embedded in the other end of the stylus 24 , the embedded laser pointer device 70 being activated or deactivated by the rotating of one end 69 B of the stylus 24 about the rotational switch 69 A, or a switch activated by the pressing of the clothing clip 68 on the side of the stylus 24 .
Optionally, an interface enables the speaker to access the Internet through either a physical wire or a wireless signal. Additionally, since some Handheld Computing Devices already have wireless connections to the Internet, it may be desirable to give the speaker a short-term Internet account to connect through the wireless connection for use in the presentation.
An exemplary embodiment of the Integrated Information Presentation System With Environmental Controls comprises of the Integrated Information Presentation Device (also known as a PowerPodium), the Integrated Presentation Environment Assembly with Controls (also known as a Presentation Booth), the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices, the stylus, and the remote control.
A second exemplary embodiment of the Integrated Information Presentation System With Environmental Controls is shown in FIG. 18 , comprising the stylus, the remote control, and the Integrated Information Presentation Device. Using this embodiment, the speaker will have all the functionality of an exemplary embodiment of the Integrated Information Presentation Device, the maneuverability provided by the use of an exemplary embodiment of the remote control, and the ability the select on a touch-screen and highlight on the audience screen using an exemplary embodiment of the stylus.
A minimal embodiment of the Information Presentation System With Environmental Controls comprises the Integrated Information Presentation Device.
An alternative minimal embodiment of the Information Presentation System With Environmental Controls comprises the Integrated Presentation Environment Assembly with controls.
An alternative minimal embodiment of the Information Presentation System With Environmental Controls comprises the Personal Handheld Computing Device Presentation System to Interact with Various Projection Devices.
The above-described presentation system can be implemented on a special purpose computer or on a separate programmed general purpose computer having a communications device. Additionally, the systems and methods of this invention can be implemented on a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element(s), an ASIC or other integrated circuit, a digital signal processor, a hard-wired electronic or logic circuit such as discrete element circuit, a programmable logic device such as PLD, PLA, FPGA, PAL, or the like. In general, any device capable of implementing a state machine that is in turn capable of implementing the flowcharts illustrated herein can be used to implement the various methods according to this invention.
Furthermore, the disclosed methods may be readily implemented in software using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation platforms. Alternatively, the disclosed system may be implemented partially or fully in hardware using standard logic circuits or VLSI design. Whether software or hardware is used to implement the systems in accordance with this invention is dependent on the speed and/or efficiency requirements of the system, the particular function, and the particular software or hardware systems or microprocessor or microcomputer systems being utilized. The systems and methods illustrated herein however can be readily implemented in hardware and/or software using any known or later developed systems or structures, devices and/or software by those of ordinary skill in the applicable art from the functional description provided herein and with a general basic knowledge of the computer and communications arts.
Moreover, the disclosed methods may be readily implemented in software executed on programmed general purpose computer, a special purpose computer, a microprocessor, or the like. In these instances, the systems and methods of this invention can be implemented as program embedded on personal computer such as JAVA® or CGI script, as a resource residing on a server or graphics workstation, as a routine embedded in a dedicated system, or the like. The system can also be implemented by physically incorporating the system and method into a software and/or hardware system, such as the hardware and software systems of a presentation server.
It is therefore apparent that there has been provided, in accordance with the present invention, systems and methods for enhanced presentation presenting. While this invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, it is intended to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of this invention. | An integrated information presentation system includes environmental controls that at least enhances the experience of giving a presentation. During the presentation, multiple controls are available which enable the presenter to have direct control of the presentation environment. The system makes it easier to give presentations using computer-aided text, images, and sounds, yet it is far from just a tool to be used during these events themselves. Using this system, it is possible for presenters to practice a presentation before actually giving it, to transmit and/or receive a presentation, either pre-recorded or live to/from a remote location(s), to record a presentation for later distribution, to view a pre-recorded or live presentation from a remote location(s), or to upload a video or audio message to a website. This system includes an exemplary integrated information presentation device “Power Podium”) and an Integrated Presentation Environment Assembly a “Presentation Booth”). | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority under 35 U.S.C. § 120 to U.S. Provisional Appln. No. 60/633,757, filed Dec. 7, 2004, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of polymer compositions, and in particular to compositions comprising at least one thermoplastic elastomer. The polymer compositions of the invention are useful in articles of manufacture that require flexibility and are fabricated with adhesives, including sporting goods, and particularly athletic shoes.
[0004] 2. Description of the Related Art
[0005] Several patents and publications are cited in this description in order to more fully describe the state of the art to which this invention pertains. The entire disclosure of each of these patents and publications is incorporated by reference herein.
[0006] Thermoplastic elastomers are high value materials that offer desirable properties together with the convenience of melt processability and the environmental advantages of recycling. Several genera of thermoplastic elastomers are known. Two that have achieved commercial significance are the block copolymers of ethers and amides (copolyetheramides) and those of ethers and esters (copolyetheresters).
[0007] Copolyetheramides and copolyetheresters offer unique dynamic mechanical properties, such as maintaining constant flexibility over a wide temperature range, and maintaining toughness at very low temperatures. Thus, despite their high cost, these materials have found a particular utility in the sporting goods and athletic shoe industries. For example, copolyetheramides are widely used in shoe parts such as sole plates, shanks, and various other components in which low hysteresis and substantially ideal elastic recovery properties are required.
[0008] In compound structures that comprise parts made of thermoplastic elastomers, the thermoplastic elastomers are typically fastened to the other components of the structure with adhesives. In the fabrication of athletic shoes, for example, solvent-based adhesives are usually applied to the parts comprising copolyetheramides. The adhesion is generally adequate; however, adhesion failure is not uncommon, especially since constant bending and flexing is often required of the parts made from thermoplastic elastomers. Adhesion failure is a major product defect. Therefore, improving the adhesion of thermoplastic elastomeric parts is a significant goal.
[0009] More importantly, driven by environmental concerns, industry is gradually phasing out solvent-based adhesives and substituting water-based adhesives or hot-melt adhesives. In this regime, adhering copolyetheramides and copolyetheresters to other substrates becomes even more difficult. In fact, copolyetheramides simply fail to attain adequate adhesion with water-based adhesives.
[0010] In light of the foregoing, it will be appreciated that an ongoing need exists to maintain the desirable dynamic mechanical properties of thermoplastic elastomers while improving their economic efficiency and their adhesion, particularly with water based adhesives
SUMMARY OF THE INVENTION
[0011] It has now surprisingly been found that blends of maleated ethylene copolymers with thermoplastic elastomers exhibit superior bonding strength without compromising key mechanical properties.
[0012] Accordingly, in a first aspect, the present invention provides a polymer composition comprising at least one thermoplastic elastomer and at least one maleated ethylene copolymer.
[0013] In another aspect, the present invention provides an article comprising the polymer composition of the invention.
[0014] In yet another aspect, the present invention provides a compound article, in which an article comprising the polymer composition of the invention is attached to a second article by means of an adhesive.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The following definitions apply to the terms as used throughout this specification, unless otherwise limited in specific instances.
[0016] The term “maleated ethylene copolymer”, as used herein, refers to copolymers that contain ethylene and residues possessing maleic acid functionality, that is, an alpha, beta-dicarboxylic acid moiety. The alpha, beta-dicarboxylic acid moiety may be in anhydride form; alternatively, it may be unneutralized, neutralized, or partially neutralized by at least one suitable cation.
[0017] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such.
[0018] In one embodiment, the present invention provides a polymer composition comprising at least one thermoplastic elastomer and at least one maleated ethylene copolymer.
[0019] Suitable thermoplastic elastomers for use in the present invention include, without limitation, copolyetheramides, copolyetheresters, and the like. Copolyetheramides are well known in the art, as described in U.S. Pat. No. 4,230,838, 4,332,920 and 4,331,786, for example. These polymers are comprised of a linear and regular chain of rigid polyamide segments and flexible polyether segments, as represented by the general formula
wherein “PA” represents a linear saturated aliphatic polyamide sequence formed from a lactam or amino acid having a hydrocarbon chain containing 4 to 14 carbon atoms, or from an aliphatic C 6 to C 9 diamine, in the presence of a chain-limiting aliphatic carboxylic diacid having 4 to 20 carbon atoms. The polyamide has an average molecular weight between 300 and 15,000 Daltons. In this formula, “PE” represents a polyoxyalkylene sequence formed from linear or branched aliphatic polyoxyalkylene glycols, mixtures thereof or copolyethers derived therefrom. The polyoxyalkylene glycols preferably have a molecular weight of less than or equal to 6000 Daltons. The number of repeat units, “n”, is preferably sufficient so that the polyetheramide copolymer has an intrinsic viscosity of from about 0.8 to about 2.05. The preparation of these polyetheramides comprises the step of reacting a dicarboxylic polyamide, the COOH groups of which are located at the chain ends, with a polyoxyalkylene glycol that is hydroxylated at its chain ends, in the presence of a catalyst such as a tetra-alkyl ortho-titanate having the general formula Ti(OR) 4 , wherein “R” represents a linear branched aliphatic hydrocarbon radical having from 1 to 24 carbon atoms. The softness of the polyetheramide block copolymer generally increases as the relative amount of polyether units is increased. For purposes of the present invention, the molar ether:amide ratio can vary from 90:10 to 10:90, preferably 80:20 to 60:40; and the shore D hardness is less than about 70, preferably less than about 60.
[0020] The copolyetheresters are discussed in detail in patents such as U.S. Pat. Nos. 3,651,014; 3,766,146; and 3,763,109. They are comprised of a multiplicity of recurring long chain units and short chain units joined head-to-tail through ester linkages, the long chain units being represented by the formula
and the short chain units being represented by the formula
where “G” represents a divalent radical remaining after the removal of terminal hydroxyl groups from a poly (alkylene oxide) glycol having a molecular weight of about 400 to about 6000 Daltons and a carbon to oxygen ratio of about 2.0-4.3. “R” represents a divalent radical remaining after removal of hydroxyl groups from a dicarboxylic acid having a molecular weight less than about 300 Daltons. “D” represents a divalent radical remaining after removal of hydroxyl groups from a diol having a molecular weight less than about 250 Daltons. The amount of short chain ester units is preferably from about 15 to about 95 percent by weight of the copolyetherester. The preferred copolyetherester polymers are those in which the polyether segment is obtained by polymerization of tetrahydrofuran and the polyester segment is obtained by polymerization of tetramethylene glycol and phthalic acid. The softness of the copolyetherester block copolymers also generally increases as the relative amount of polyether units is increased. For purposes of the present invention, the molar ether:ester ratio can vary from 90:10 to 10:90, preferably 80:20 to 60:40; and the shore D hardness is less than about 70, preferably less than about 60.
[0021] Certain thermoplastic elastomers that are suitable for use in the present invention are available commercially. These include PEBAX™ copolyetheramides, available from the Arkema Group of Paris, France (hereinafter “Arkema”), and Hytrel® copolyetheresters, available from E.I. du Pont de Nemours & Co. of Wilmington, Del. (hereinafter “DuPont”).
[0022] The polymer composition of the invention also comprises at least one maleated ethylene copolymer. Maleic acid functionality may be included in the maleated ethylene copolymer(s) by grafting, by direct copolymerization, or by a combination of grafting and direct copolymerization.
[0023] With respect to directly copolymerized maleated ethylene copolymers, dipolymers and copolymers of four or more comonomers are suitable for use in the present invention. Terpolymers are preferred, however. Terpolymers of ethylene, vinyl acetate or an acrylic ester and an alpha, beta unsaturated dicarboxylic acid are more preferred, and terpolymers of ethylene, an acrylic ester and an alpha, beta unsaturated dicarboxylic acid are still more preferred.
[0024] Copolymers of ethylene, methyl acrylate, and maleic anhydride are examples of preferred terpolymers. The preferred terpolymers comprise from about 60 wt % to about 85 wt % of ethylene, from about 15 wt % to about 39 wt % of the acrylic ester, and from about 1 wt % to about 8 wt % of the alpha, beta unsaturated dicarboxylic acid, based on the total weight of the ethylene copolymer. More preferred terpolymers comprise from about 70 wt % to about 85 wt % of ethylene, from about 15 wt % to about 29 wt % of the acrylic ester, and from about 1 wt % to about 3 wt % of the alpha, beta unsaturated dicarboxylic acid, based on the total weight of the ethylene copolymer.
[0025] Suitable acrylic esters include, without limitation, methyl acrylate, ethyl acrylate, n-butyl acrylate and iso-butyl acrylate. Suitable alpha, beta unsaturated dicarboxylic acid monomers include, without limitation, fumaric acid, maleic acid, maleic anhydride, and the esters and half-esters of maleic anhydride, such as ethyl hydrogen maleate. Maleic acid and its esters and half-esters are preferred.
[0026] Certain directly copolymerized maleated ethylene copolymers that are suitable for use in the present invention are available commercially. Lotader™ 3200, commercially available from Arkema, is an example of a terpolymer of ethylene, butyl acrylate, and maleic anhydride.
[0027] Ethylene copolymers suitable for use as substrates onto which maleic acid functionality may be grafted include, without limitation, copolymers of ethylene and a vinyl alkanoate, preferably ethylene/vinyl acetate copolymers. Alternatively, the copolymer may be a copolymer of ethylene and an acrylate ester, for example ethylene/ethyl acrylate copolymers, ethylene/methyl acrylate copolymers and ethylene/butyl acrylate copolymers. Similarly, the copolymer may be a copolymer of ethylene and a methacrylate ester, such as ethylene/methyl methacrylate.
[0028] In addition, the grafting substrate may be a copolymer of ethylene with carbon monoxide, optionally further including one of the aforementioned monomers, such as, e.g., ethylene/carbon monoxide, ethylene/alkyl acrylate/carbon monoxide, and ethylene/vinyl acetate/carbon monoxide copolymers. In ethylene/alkyl acrylate/carbon monoxide copolymers, the preferred alkyl groups are straight chain or branched groups including one to four carbon atoms. Ethylene/butyl acrylate/carbon monoxide (E/nBA/CO) copolymers are particularly preferred.
[0029] The more preferred grafting substrate copolymers are those of high polarity, such as ethylene/alkyl acrylate/carbon monoxide, ethylene/vinyl acetate/carbon monoxide, ethylene/vinyl acetate (EVA), and ethylene/acrylate copolymers. Still more preferably, the vinyl acetate content of the EVA copolymer and the ethylene/vinyl acetate/carbon monoxide copolymer is greater than about 15 wt % and less than about 40 wt %, based on the total weight of the respective copolymer. Likewise, the alkyl acrylate content of the ethylene/alkyl acrylate or ethylene/alkyl acrylate/carbon monoxide copolymer is also preferably greater than about 15 wt % and less than about 40 wt %, based on the total weight of the respective copolymer. In the case of ethylene/alkyl acrylate/carbon monoxide copolymer, the carbon monoxide content is preferably in the range of about 5 to about 15 wt %.
[0030] Any known grafting process may be used to produce a maleated ethylene copolymer for use in the present invention. Examples of suitable maleation processes are set forth in U.S. Pat. No. 5,106,916. Additional information pertaining to the preparation and use of maleated polyethylenes is available in U.S. Pat. No. 6,545,091.
[0031] Briefly, however, the preferred monomers to be grafted onto polymers are: maleic anhydride, maleic acid, half-esters of maleic anhydride, such as ethyl hydrogen maleate, itaconic acid and fumaric acid. More preferred monomers include maleic anhydride and its half-esters. The grafting can be carried out in solution, in dispersion, in a fluidized bed, or in the melt without a solvent, as described in European Patent Application No. 0,266,994. Melt grafting can be done in a heated extruder, a Brabender™ or a Banbury™ mixer or other internal mixers or kneading machines, roll mills and the like. The grafting may be carried out in the presence or absence of a radical initiator such as a suitable organic peroxide. The graft polymers may be recovered by any method that separates or utilizes the graft polymer. Thus, the graft polymer can be recovered in the form of precipitated fluff, pellets, powders and the like.
[0032] The preferred level of grafted monomer in the maleated ethylene copolymer is in the range of about 0.3 to 3.0 wt %, more preferably 0.5 to 1.5 wt %, based on the weight of the copolymer.
[0033] Ethylene copolymers can be produced by processes well known in the polymer art using either autoclave or tubular reactors. The copolymerization can be run as a continuous process in an autoclave as disclosed in U.S. Pat. No. 3,264,272; 4,351,931; 4,248,990; and 5,028,674 and International Patent Application WO99/25742. Tubular reactor-produced ethylene copolymer can be distinguished from the more conventional autoclave produced ethylene copolymer as generally known in the art. Tubular reactor-produced ethylene copolymer are well known to one skilled in the art such as disclosed in U.S. Pat. Nos. 3,350,372; 3,756,996; and 5,532,066; the description of which is omitted herein for the interest of brevity. See also, “High flexibility EMA made from high pressure tubular process,” Annual Technical Conference—Society of Plastics Engineers (2002), 60 th (Vol. 2), 1832-1836.
[0034] The compositions according to the invention preferably contain from about 60 to about 95 wt % of the thermoplastic elastomer(s), based on the total weight of the polymer composition, more preferably 70 to 90 wt %, and still more preferably 75 to 85 wt %.
[0035] It follows arithmetically that the compositions according to the invention preferably contain from about 5 to about 40 wt % of the maleated ethylene copolymer(s), based on the total weight of the polymer composition, more preferably 10 to 30 wt %, and still more preferably 15 to 25 wt %.
[0036] The polymer compositions of the invention may also include such additives as are conventional in polymer compositions, for example, antioxidants, UV stabilizers, flame retardants, plasticizers, pigments, fillers, reinforcements, processing aids, and the like. Suitable levels of these additives and methods of incorporating these additives into polymer compositions are known to those of skill in the art. See, e.g., the Modern Plastics Encyclopedia, McGraw Hill, (New York, 1994).
[0037] The polymer compositions of the invention may be made by blending the individual components by any suitable means known in the art. For example, the individual materials can be mixed with each other in molten form, such as by melt blending in an extruder. Alternatively, the individual materials can be blended with each other in a high shear mixing device, such as a two-roll mill or a Banbury mixer.
[0038] In another aspect, the present invention provides an article comprising the polymer composition of the invention. Preferred articles of the invention include footwear components such as sole plates and shanks. Such articles may be made according to methods that are well known in the art. For example, the polymer composition of this invention can be formed by normal thermoplastic forming methods such as extrusion, blown film extrusion, injection molding, rotational molding, thermoforming, or any other technique that will produce the desired shape. Injection molding is a preferred method of forming articles according to the invention.
[0039] In yet another aspect, the present invention provides a compound article, in which an article comprising the polymer composition of the invention is attached to a second article by means of an adhesive. The adhesive may be a water-based adhesive, a solvent-based adhesive, or a hot-melt adhesive. Preferred adhesives are available commercially from the National Starch Company through Dongsung NSC of Kyunggi, Republic of Korea (hereinafter “Dongsung NSC”). Preferably, the adhesive includes a polyurethane. The second article may be any article that is also compatible with the adhesive. Preferably, the second article comprises a rubber.
[0040] The compound article according to the invention may be made by any suitable means known in the art. For example, the article comprising the composition of the invention and the second article may both be placed in contact with an adhesive. Alternatively, the article comprising the composition of the invention may be pre-formed and at least partially coated with an adhesive when the second article is formed by molding it directly in contact with the adhesive. Likewise, the second article may be pre-formed and at least partially coated with an adhesive when the article comprising the composition of the invention is formed by molding it directly in contact with the adhesive.
[0041] Preferably, the polymer compositions of the present invention are used to make articles for use in sporting goods, and particularly, components of athletic shoes. It is to be understood, however, that the articles and methods described herein are considered to be within the scope of the invention, whether they are used in sporting goods or in a different application. Examples of suitable articles that may be fabricated from a polymer composition of the invention include, without limitation, sole plates, shanks, and the like. Also the polymer compositions of the present invention may be used for in-line skates, ski boots and bindings, and the like, which are compound articles according to the invention.
[0042] The following examples are provided to describe the invention in further detail. These examples, which set forth a preferred mode presently contemplated for carrying out the invention, are intended to illustrate and not to limit the invention.
EXAMPLES
[0000] 1. Materials
[0043] Pebax™ 7033, Pebax™ 6333 and Pebax™ 5533 were supplied by Arkema. The maleated ethylene copolymer is a maleic anhydride grafted terpolymer of E/nBA/CO (weight ratio of 60/30/10) containing about 1.0 wt % of maleic anhydride residues. The maleated ethylene-methyl acrylate copolymer (E/MA) is a maleic anhydride grafted E/MA (weight ratio of 76/24) containing about 1.0 wt % of maleic anhydride residues. The maleic anhydride grafting was conducted in a twin screw extruder in a similar process similar to that described in U.S. Pat. No. 5,106,916.
[0044] The test specimen of Comparative Example 1 is unalloyed Pebax™ 7033. The test specimen of Example 1 is an 80:20 blend of Pebax™ 7033 with the maleated ethylene copolymer, and the specimen of Example 2 is a 70:30 blend. The test specimen of Comparative Example 2 is unalloyed Pebax™ 5333. The test specimen of Example 3 is a blend of Pebax™ 5533, 36 wt. %, Pebax™ 6633, 56 wt %, the maleated ethylene copolymer, 8 wt. %, and the maleated ethylene-methyl acrylate copolymer, 6 wt %. The blends of Pebax™ and the maleated ethylene copolymer were prepared in a twin screw extruder. Test specimens (2.54 mm×15 mm×3.5 mm) were formed by injection molding at about 220° C. to 230° C.
[0000] 2. Standard Test Methods
[0045] Hardness was measured according to ASTM D792. Tensile modulus, tensile strength and tensile elongation were measured according to ASTM D638. Tear strength was measured according to ASTM D642C. Ross flex value was measured according to ASTM D1052. The peel strength specimens of Pebax™ and the Pebax™ blends, after bonding to polybutadiene rubber, were tested using a universal material testing machine available from the Instron Corporation of Canton, Mass. The cross head speed was 50 mm/min. The results of these measurements are set forth in Tables 1 and 2, below.
[0000] a. Solvent-Based Primer
[0046] The test specimens were first cleaned with methyl ethyl ketone (MEK) at room temperature, then a solvent-based primer was applied (Dongsung NSC D-PLY 160-2), followed by drying at 60 to 65° C. in a convection oven. A solvent-based polyurethane primer (Dongsung NSC W-104) was applied to the test specimens, which were then dried at 50 to 55° C. in an oven. A water-based polyurethane adhesive (Dongsung NSC W-01) was then applied to the primed test specimens, which were subsequently dried at 55 to 60° C., followed by degreasing the surfaces with toluene and further drying at 50 to 55° C. A solvent-based primer (Dongsung NSC D-PLY 007) was then applied to the test specimens, followed by a water-based polyurethane adhesive (Dongsung NSC W-01). Then the specimens were molded with polybutadiene rubber at a pressure of 30 kg/cm for 210 seconds, prior to measuring the peel strength.
[0000] b. Water Based Primer
[0047] The test specimens were first cleaned with methyl ethyl ketone (MEK) at room temperature, then a water-based polyurethane primer (Dongsung NSC W-104) was applied to the test specimens, which were then dried at 50 to 55° C. in an oven. A water-based polyurethane adhesive (Dongsung NSC W-01) was then applied to the primed test specimens, which were subsequently dried at 55 to 60° C., followed by degreasing the surfaces with toluene and further drying at 50 to 55° C. A water-based polyurethane primer (Dongsung NSC W-104) was then applied to the test specimen, followed by a water-based polyurethane adhesive (Dongsung NSC W-01). Then the specimen were molded with polybutadiene rubber at pressure of 30 kg/cm for 210 seconds, prior to measuring the peel strength.
[0000] 3. Results and Discussion
[0048] The compositions of Example 1 and Example 2 are well matched with Comparative Example 1 in each of the key properties listed in Table 1. For example, the test specimens of both Examples 1 and 2 displayed excellent Ross flex test results at room temperature and at −10° C.
[0049] Table 1 also includes the bonding strength of the test specimens of Comparative Example 1 and Examples 1 and 2 towards rubber, using both solvent-based and water-based adhesives. With the solvent-based adhesives, the bonding strength of the specimen of Example 1 toward rubber is in the range of 19.1 to 23.3 kg/cm, far better than that of the specimen of Comparative Example 1. With the water-based adhesives, the bonding strength of the specimen of Example 1 shows an improvement over that of the specimen of Comparative Example 1. The specimen of Example 2, with its greater content of maleated ethylene copolymer, shows significant improvement in its bonding strength towards rubber with water-based adhesives. The lower bonding strength of the specimen of Example 2 with the solvent-based adhesives is an unexpected result that may reflect a change in the nature of the surface of this specimen.
TABLE 1 Properties of Polymer Blends Comparative Example 1 Example 2 Example 1 Pebax ™ Pebax ™ Pebax ™ 7033/MEC* 7033/MEC 7033 (80/20%) (70/30%) Bonding (kg/cm) 10˜14 (pass, 19.1˜23.3 1.9˜3.5 solvent-based primer but frequent fail) Bonding (kg/cm) Fail 2.1˜4.2 (fail) 4.1˜7.0 (pass) water-based primer Hardness (Shore D) 69 57 55 Specific gravity (g/cc) 1.02 1.012 1.007 Modulus (kg/cm 2 ) 320 306 292 Tensile Strength(kg/cm 2 ) 435 332.6 303.5 Elongation (%) 395 375 325 Tear (kg/cm) 20.1 18.8 17.3 Flex Ross (cycle) Pass 100,000 Pass 100,000 Pass 100,000 at −10° C. Flex Ross (cycle) at RT Pass 150,000 Pass 150,000 Pass 150,000 *In Table 1, “MEC” is an abbreviation of “maleated ethylene copolymer.”
[0050] Table 2 includes the bonding strength of the test specimens of Comparative Example 2 and Example 3 towards rubber, using solvent-based primer. In order to obtain statistically significant results, 24 test specimens of each of Comparative Example 2 and Example 3 were produced for bonding strength measurements. As is set forth in Table 2, the composition of Example 3 shows an average bonding value of 10.5 kg/cm and a minimum bonding value of 6.4 kg/cm. The composition of Comparative Example 2 shows an average bonding value of 7.1 kg/cm and a minimum bonding value of 0.4 kg/cm. Out of 24 specimens, 7 specimens of Comparative Example 2 exhibited bonding strength less than 2.0 kg/cm, which is too low, indicating that this composition is vulnerable to failure in the contemplated applications.
TABLE 2 Bonding Strength of Polymer Blends Bonding (kg/cm), solvent- based primer Average Maximum Minimum value value value Comparative 7.1 14.1 0.4 Example 2 Example 3 10.5 14.9 6.4
[0051] While certain of the preferred embodiments of the present invention have been described and specifically exemplified above, it is not intended that the invention be limited to such embodiments. Various modifications may be made without departing from the scope and spirit of the present invention, as set forth in the following claims. | Polymer compositions having thermoplastic and elastomeric features are provided. These polymer compositions, which are also characterized by superior compatibility with water-based and solvent-based adhesives, comprise at least one thermoplastic elastomer and at least one maleated ethylene copolymer. The compositions of the invention are useful in articles of manufacture that require flexibility and are fabricated with adhesives, including sporting goods, and particularly athletic shoes. | 2 |
FIELD OF THE INVENTION
The invention relates to the field of data transmissions and in particular to devices and methods which provide packet network address resolution.
BACKGROUND TO THE INVENTION
Address resolution is a key function of network equipment such as routers and switches. The source, destination, and media access rights of network packets are usually determined using the addresses contained within the packets. Usually, forwarding decisions, such as where to deliver a data packet, are made based on at least one of the addresses carried in the data packet. These addresses are used as the key to determine from a database, containing address dependent information, which egress or exit port the packet should be sent to, or more generally, how the packet should be processed. Given that the forwarding decision is to be made for each packet, address resolution must therefore be performed for each packet. Address resolution entails extracting the different addresses from within the packet and using these addresses in a database lookup procedure to find the required routing information. The database lookup procedure can require up to several lookup operations based on source and destination addresses of several network protocol layers. Because modern switches and routers need to deal with a number of ports running at high speed, with each port receiving or transmitting multiple pockets, providing fast address resolution becomes a challenging problem to solve.
The problem of fast address resolution is exacerbated by the numerous lookup procedures used to perform required network routing functions such as MAC (medium access control) lookup and IP (internet protocol) longest prefix match lookup. Procedures such as hashing, multi-stage table lookup, and caching have been developed to perform these functions.
Ethernet layer 2 MAC address lookup and layer 3 IP longest prefix match are required in numerous networks. In the Ethernet standard, each network device is assigned a unique hexadecimal serial number, a MAC address, which identifies it on the network. Because of this scheme and the uniqueness of the MAC address of every device on the network, each network device can monitor network traffic and look for its own MAC address in each packet to determine if that packet should be decoded or not. Specific network devices, such as routers, switches and bridges, are able to determine the network source and destination of a packet simply by monitoring the MAC addresses within that packet. With this data, the network device can determine whether the packet should be decoded or not. By way of an example, a learning bridge can, by monitoring MAC addresses in packets, determine which addresses are on which side of a connection. By monitoring the source and destination MAC addresses in packets, a learning bridge can determine, when it receives a packet, whether that packet must cross the bridge or not.
Given the number of packets a network device receives, a fast MAC address lookup is desirable. One widely used procedure for MAC address lookup has been hashing. By way of example, if we wish to have B classes numbered 0,1, . . . , B- 1 , then we use a hash function h such that for each object x, h(x) is one of the integers 0 through B- 1 . The value of h(x) is the class to which x belongs. x is therefore the key and h(x) is the hash value of x. The “classes” are normally referred to as buckets such that it is customary to refer to x as belonging to bucket h(x).
With respect to MAC address lookup, such a hash structure is used. FIG. 1 illustrates the procedure. The 48 bit MAC address 10 is used to calculate a hash key 20 that indexes the hash table 30 . Each hash table entry 40 contains a head pointer to the linked list of hash buckets 50 for the MAC addresses with the same hash key. The hash bucket header contains the MAC address 55 , the next pointer for the linked list 57 , and the forwarding context data structure 59 that is defined by the application that uses the address resolution system.
The MAC address lookup procedure begins with the address extraction. The MAC address is extracted by simple offsetting—the MAC address is found at a specific predetermined offset from the beginning of each packet. The extracted MAC address 10 is used to calculate the hash key 20 . The head pointer of the hash bucket chain is fetched from the hash table 30 using the hash key 20 . The address resolution system recursively fetches the hash bucket header and compares the MAC address stored in the bucket header with the MAC address that is being looked up until either a match is found or the end of the linked list is reached. After finding a match, the address resolution system fetches the remaining part of the hash bucket and presents it as the lookup result.
IP addresses, on the other hand, are the actual addresses which determine the logical location of a network node on the network. Routers, devices which determine the route a packet must take to reach its destination IP address, must correctly determine for each incoming packet which port to send the packet and the next hop that packet must take. For each incoming packet, a search must be performed in the router's forwarding table to determine which next hop the packet is destined for.
One longest prefix match procedure that combines speed with ease of hardware implementability is the multistage lookup procedure outlined by Gupta et al. in “Routing Lookups in Hardware at Memory Access Speeds”, IEEE Infocom , April 1998. A modified version of the Gupta et al procedure simplifies the lookup procedure and simplifies its implementation.
In this modified version of the Gupta et al procedure, conceptually illustrated in FIG. 3, the IP address database contains three separate route tables and the route context table. The route tables RT 0 , RT 1 , and RT 2 are segmented to provide for routes of various prefix lengths. Route table RT 0 provides for all routes of prefix length 17 or less while route table RT 1 provides for all routes of prefix length 18 to 24 and route table RT 2 provides for routes of prefix length 25 and longer. All three route tables contain entries of identical format as shown in FIG. 2 . Each entry has two 16-bit records, each record containing two control bits, a VALID bit 62 and an INDIRECT bit 64 , and a 14-bit memory index 66 . The base addresses for the route tables are predetermined and set, making it easier to reference each route table independent of the others. Once the correct route is found, the memory pointer in the record points to an entry in the Route Context table RC. (It should be noted that in this example, a 32-bit memory width is assumed. Thus, each route table entry can accomodate two 16-bit records. However, this procedure can be adapted for implementation in any computer system. Ideally, each route table can be seen as simply a collection of 16-bit records.) Given a destination IP address, the procedure begins by extracting the most significant 17-bits 72 of the destination IP address contained in the input packet. The predetermined base address 73 of the first route table RT 0 is added to the 17 bits 72 extracted from the given destination IP address, thereby forming a complete memory address 74 to a selected entry in the first route table RT 0 . This first route table RT 0 contains entries for all established routes of 17-bit prefix length or less.
As noted above, each entry in the first route table RT 0 contains a 14 bit memory index 66 . For routes with prefix length 17 bits or less, the memory index 66 is a pointer into a route context table RC. For routes longer than 17 bits, the INDIRECT control bit 64 in the route table RT 0 entry is set, indicating that the 14 bit memory index 66 contained in the route table RT 0 table entry is to be used as a pointer to index into a second route table RT 1 . The index into route table RT 1 from the route table RT 0 table entry is concatenated with the following 7 bits 75 of the given destination IP address and the predetermined base address 76 of the second route table RT 1 to form a complete address 77 of a selected entry in the second route table RT 1 .
Since this second route table RT 1 contains entries having the same format as the entries in the first route table RT 0 , the INDIRECT control bit 64 in the entry in route table RT 1 designates whether the memory index 66 in the route table RT 1 entry points to an entry in the route context table RC or whether it is to be used as an index into a third route table RT 2 . For routes of prefix lengths 18 - 24 the INDIRECT control bit 64 in the route table RT 1 entry should not be set, thereby indicating that the memory index 66 in the route table RT 1 entry should point to an entry in the route context table RC. For routes with a prefix length longer than 24 , the INDIRECT control bit 64 should be set, thereby indicating that the memory index 66 in the route table RT 1 entry is to be used as a pointer to index a third route table RT 2 .
If the INDIRECT bit 64 is set in the entry in the second route table RT 1 , the least significant 8 bits 78 of the given destination IP address is concatenated with the memory index 66 found in the selected route table RT 1 entry and the predetermined base address 79 of the third route table RT 2 , thereby forming a complete address 81 of an entry in the third route table RT 2 . In this third and final route table RT 2 , the INDIRECT bit 64 is not used and the memory index 66 contained in the entry is used to index into the route context table RC.
If, in any of the above steps, the VALID bit 62 is not set, then the IP address being searched for is invalid and the search must terminate. If a specific IP address does not have an entry in the route table RT 2 , even after passing through route tables RT 1 and RT 0 , then that specific IP address is considered invalid and the search also terminates.
The route context table RC contains the addresses of exit ports. Through the modified Gupta et al procedure outlined above, an entry in the route context table RC is selected for a given destination IP address, thereby determining which exit port should be used by a packet with the given destination IP address. This defines the next hop that the data packet must take.
Given the above procedure, the steps taken to find a route context will be illustrated.
By way of example, assume that the route context RC table entries for six destination IP addresses A,B,C,D,E,and F are to be determined. For simplicity, assume that X 17 refers to the most significant 17 bits of the IP address X, that X 7 refers to the following 7 bits of the destination IP address X, and that X 8 refers to the least significant 8 bits of the same address. For this example, we can assume that the table entries for RT 0 , RT 1 , and RT 2 are as shown in FIG. 4 following the format outlined in FIG. 2 . For this example, the following examples will have the following meanings :
BA RTx —Base address of Rtx
RT 0 (x)—entry x in route table RT 0 (similar notations will be used for the other route tables and for the route context table)
Taking IP address A first, if BA RT0 +A 17 −>RT 0 ( 3 ) (meaning that adding the base address of RT 0 to the most significant 17 bits of A yields entry 3 in RT 0 ), then the index to RT 1 is 5 .
Therefore, from the table entries in FIG. 4 ,
BA RT0 +A 17 −>RT 0 ( 3 )=> BA RT1 +5 +A 7 −>RT 1 (5 +A 7 )=> RC ( 112 )
This means that the final end result is entry 112 in the Route Context table.
Similarly, we can follow the following operations for the other addresses:
BA RT0 +B 17 −>RT 0 ( 5 )−> RC ( 100 )
BA RT0 +C 17 −>RT 0 ( 8 )= BA RT1 +7 +C 7 −>RT 1 ( 7 )−>INVALID
BA RT0 +D 17 −>RT 0 ( 7 )−>INVALID
BA RT0 +E 17 −>RT 0 ( 6 )−> RC ( 110 )
BA RT0 +F 17 −>RT 0 ( 4 )= BA RT1 +6 +F 7 −>RT 1 (6 +F 7 )= BA RT2 +12 +F 8 −>RT 2 ( 12 )−> RC ( 119 )
We can summarize the results of the search for the route contexts of the addresses as follows:
A−>RC( 112 )
B−>RC( 100 )
C−>INVALID
D−>INVALID
E−>RC( 110 )
F−>RC( 119 )
The two above procedures for MAC address lookup and IP longest prefix match suffer from one drawback or another when implemented in either hardware or software using traditional methods used to increase the throughput of an address resolution system.
One traditional method is the use of a sequential processing unit. In this method, the logic is designed to follow the control path of the look-up flow chart with the address resolution process being completed in sequential steps, including database lookup and address extraction. Unfortunately, this method provides a low throughput.
Another traditional method is the use of a pipelined processing unit. In this method, the address resolution process is divided into a fixed number (N) of steps with the search context being passed along the pipeline as each step of the processing is completed. At most, N address look-up threads can be processed in parallel. However, to have an efficient pipeline, the process must be divided into a fixed number of processing stages with each stage requiring an equal amount of processing time. Unfortunately, most hash look-up procedures and multistage memory look procedures have an indeterministic but bounded number of look-up steps, with the next step being determined by the intermediate result of the previous step. The dynamic nature of such procedures therefore makes this static pipelining approach unsuitable.
A third method uses a channelized processing unit. Multiple parallel instances of this processing unit is replicated in a multi-channel system with each channel comprising separate address resolution search engines running in parallel to other channels. Ideally, system performance should scale with the number of processing units. However, this is not the case. Given N instances of identical processing units, the actual system performance speedup is between log 2 N and N/ln N (see Computer Architecture and Parallel Processing, K Hwang and Briggs, McGraw-Hill Publishing company, 1984, pp 27-29). Also, this method can be quite expensive given that either multiple parallel instances of RAM must be used to store the look-up database or a multi-port shared memory access controller is required to arbitrate the memory accesses among the search engines. While the multi-port shared memory structure may be efficient, having multiple separate search engines along with a memory access controller with a large number of ports is not.
Accordingly, given the unsuitability, inefficiency, and cost considerations of the traditional methods used to increase the speed of address resolution systems, what is required is a method or device that can be used with different lookup procedures such as hashing and multistage lookup without incurring the drawbacks of the traditional methods.
SUMMARY OF THE INVENTION
The present invention is a method and a module for executing different database lookup procedures for resolving network addresses. Separate modules are used for each database lookup procedure allowing multiple, independent lookup procedures to be implemented on the same system. Within each module, at least two processing units, each processing unit operating independently of one another and each processing unit coupled to a memory and to one another by data pipelines, divide the database lookup procedure into multiple stages. A feedback loop between at least two of these processing units is implemented using data pipelines, thereby allowing complex branching and looping functions between the processing units. Also within the modules, the data pipelines and the independently operating processing units allow multiple database lookup threads to execute independently of one another, thereby increasing system throughput.
By having at least two processing units per module, the modules are scalable within themselves and hence adaptable to different database lookup procedures. Furthermore, the feedback loop within the module allows for the implementation of database lookup procedures that have a dynamic number of steps.
Data pipelines also couple separate modules, allowing data exchange between the modules.
It should be noted that for the purposes of this application a data pipeline is defined as a hardware device or a software data structure that has the properties of a queue or of a FIFO (first-in first-out) list or register. By this definition, a data pipeline receives all incoming data at a receiving end and buffers this data in the order the data was received. The data pipeline then transmits the buffered data at a transmitting end, again in the order in which the data was received.
It should also be noted that a search context for the purposes of this application is defined as data required not only to identify a search but also to define that search. A search context therefore includes a search identifier that identifies the specific search thread in a multithreaded search system and search parameters that determine not only what is being sought but also determines the scope of that search.
In accordance with an embodiment of the invention, a module for executing a multiple step database lookup procedure includes a plurality of processing units, each processing unit executing at least one step in the multiple step database lookup procedure with at least two processing units being coupled to a memory containing a database and having multiple input and output ports, and a plurality of data pipelines which couple the plurality of processing units to each other and to external modules.
In accordance with another embodiment of the invention, a device for resolving the routing of network packets, with each packet containing at least one network address, includes a search engine comprised of a plurality of modules including at least one search module, each search module executing a specific database search lookup procedure which retrieves from a memory data related to the at least one network address.
In accordance with a third embodiment of the invention, a method of executing a multiple step address resolution procedure comprises:
a) receiving a search context at a search unit,
b) initiating a memory request using search data contained in the search context,
c) transmitting the search context to a compare unit,
d) receiving data at the compare unit, said data including:
the search context,
a memory result of the memory request initiated by the search unit,
e) determining at the compare unit if further searching is required based on the memory result and search data contained in the search context,
f) modifying at the compare unit the search context to produce a modified search context based on the memory result and if further searching is required,
g) transmitting the modified search context to the search unit if further searching is required,
h) transmitting the modified search context to an external unit if further searching is not required.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention may be obtained by reading the detailed description of the invention below, in conjunction with the following drawings, in which:
FIG. 1 is a block diagram of a hashing lookup procedure implemented by the invention,
FIG. 2 is a diagram illustrating the format of a route table entry,
FIG. 3 is a block diagram illustrating the modified Gupta et al procedure implemented by the invention,
FIG. 4 are sample route lookup tables used in the examples explaining the multistage route lookup technique,
FIG. 5 is a block diagram of a hardware module according to the invention,
FIG. 6 is a block diagram of a hardware implementation of an address resolution system using two modules according to the invention and implementing the hash lookup procedure and the modified Gupta et al procedure,
FIG. 7 is a flowchart diagram illustrating the steps taken by the address resolution system illustrated in FIG. 6 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 5, a module 1 for implementing database lookup procedures is illustrated. A memory request unit 90 is coupled to a compare unit 91 via a data pipeline 92 . The memory request unit 90 is also coupled to a memory 93 that contains the database 94 being accessed. Data pipelines 95 , 96 , 97 are also coupled to either the memory request unit or the compare unit 91 . The data pipeline 96 provides a feedback loop between the memory request unit 90 and the compare unit 91 . If a database search is insufficient or incomplete, the compare unit 92 can send the search back to the memory request unit 90 via the data pipeline 96 .
The data pipeline 95 is coupled to receive input data (normally a search context) from an external module and buffer and retransmit that input data to an input of the memory request unit 90 . Data pipeline 92 is coupled to receive an output of the memory request unit 90 for buffering and retransmission to an input of the compare unit 91 . The memory request unit 90 also has an output coupled to an input of the memory 93 for accessing the database 94 .
The compare unit 91 has an input coupled to receive data from the data pipeline 92 . The compare unit 91 also has an output coupled to the data pipeline 96 which provides a feedback loop for the module 1 . The data pipeline 96 buffers and retransmits an output of the compare unit 91 to an input of the memory request unit 90 .
The compare unit 91 also has an input from an output of the memory 93 . This input from the memory 93 receives the results of the memory request initiated by the memory request unit 90 . The compare unit can also receive an input from an external source 98 . Whether this external input is used or even present depends on the database lookup procedure implemented. The compare unit 91 has an output coupled to a data pipeline 97 . The data pipeline 97 is coupled to at least one other external module.
A database search starts with data pipeline 95 receiving a search context from outside the module. The search context includes a search identifier and search parameters. The data pipeline 95 , if there are other search contexts that have been previously received but not yet transmitted to the memory request unit 90 , buffers the received search context. Since the data pipeline 95 has the qualities of a FIFO list, the search contexts are transmitted to the memory request unit 90 in the order they are received by the data pipeline 95 .
Once the search context is received by the memory request unit 90 , it then determines from the search parameters contained in the search context the proper memory request to be initiated. This means that the memory request unit 90 determines what database entry needs to be requested and initiates that request. The memory request unit 90 , when it initiates the memory request, passes on to the memory 93 , an indicator as to the identity of the search. The memory request unit 90 , after initiating the memory request, transmits the search context to the data pipeline 92 for buffering and eventual transmission to the compare unit 91 .
In the memory 93 , after the memory request unit 90 has initiated the memory request, a memory request result is transmitted to the compare unit 91 along with the indicator as to the identity of the search.
At the compare unit 91 , once the search context is received from the data pipeline 92 the memory request result received from the memory 93 is matched with the proper search context using the indicator as to the identity of the search. The compare unit 91 then determines if further searching is required. If required, this can be done in conjunction with data received by the compare unit 91 from an outside source 98 . For example, if the search is for specific data such as a bit pattern, the outside source 98 transmits the desired bit pattern to the compare unit 91 . In this example, the compare unit 91 then compares the memory request result with data from the outside source 98 .
Depending on the result of the comparison, the compare unit 91 then transmits a modified search context to either the data pipeline 96 for further searching or to the data pipeline 97 for transmission to another module.
Alternatively, depending on the lookup procedure implemented, the compare unit 91 may simply check if a flag is set in the memory request result to determine if further searching is required.
If further searching is required, the compare unit 91 modifies the search context by changing the search parameters. Once the search parameters have been modified, the compare unit 91 transmits the modified search context to the data pipeline 96 for eventual retransmission to the memory request unit 90 . The memory request unit 90 then initiates a new memory request based on the modified search parameters contained in the modified search context.
It should be noted that the data pipelines 95 , 92 , 96 , and 97 have synchronization mechanisms which prevent them from receiving further data once their buffers are full. If, for example, data pipeline 92 has resources to buffer five search contexts, once five search contexts have been received and the buffers of data pipeline 92 are full, a signal is sent to the memory request unit 90 indicating the full condition of data pipeline 90 . When the memory request unit 90 receives this signal, it does not transmit any more search contexts to data pipeline 92 until the full signal is has been cleared by data pipeline 92 . Similar overflow prevention mechanisms are used with data pipelines 95 , 96 and 97 .
An alternative mechanism can take the form of a flag set by the data pipeline when the pipeline is full. Before sending data to the data pipeline, a processing unit can check if the flag is set. If the data pipeline is full, then the flag should be set, signalling to the processing unit not to transmit data. The processing unit therefore does not transmit data until the flag is cleared, indicating that the data pipeline is ready and capable of receiving further data.
Referring to FIG. 6, an address resolution system 100 using two search modules 110 , 120 implementing database lookup procedures is illustrated. The module 110 implements a hashing procedure for the MAC address lookup as outlined above. The module 120 implements the modified Gupta et al procedure also as outlined above. A third module 125 performs search result reporting procedures.
The address resolution system 100 performs a MAC address lookup by implementing a hashing procedure and performs the modified Gupta et al procedure for IP longest prefix match. The two modules 110 , 120 are contained in an address search engine 150 .
For clarity, FIG. 7 is a flow chart detailing the workings of the address resolution system 100 and more specifically, the workings of the modules 110 , 120 . Block 110 A details the course followed by module 110 while the block 120 A details the course followed by module 120 . Block 100 A details the actions of header control unit 130 illustrated in FIG. 6 .
Block 100 A shows the preliminary search function carried out by the header control unit 130 such as extracting the addresses to be searched and calculating the hash key.
Block 110 A shows the general steps of the hashing procedure carried out by the module 110 .
Block 120 A shows the general steps of the modified Gupta procedure as implemented by module 120 .
To initiate a search, the address resolution system 100 receives a network data packet and, using the header control unit 130 , extracts required addresses from the data packet. These required addresses can include a source MAC address, a destination MAC address, and a destination IP address.
Once the relevant addresses have been extracted by the header control unit 130 , a search context is formulated by the header control 130 to be transmitted to the data pipeline 140 . If the data packet is an IP data packet, the IP destination address is included in the search context along with a flag that indicates the need for a target IP search and a current step counter detailing which step in the modified Gupta procedure is being executed. If the current step counter is included in the search context, then the counter is initialized with a value of 0.
Also included in the search context are search identifiers assigned by the header control, and a MAC address to be searched. Since the hash procedure outlined above is used for the MAC address lookup, a hash table entry address, calculated by the header control 130 using the MAC address to be searched as the hash key, is also included in the search context. Thus, the search context contains an assigned search identifier, which can be the MAC address to be searched, along with the relevant search parameters such as the hash table entry address, and, if the data packet is an IP data packet, the destination IP address.
Once the search context is transmitted to the data pipeline 140 , the search context is buffered for retransmission to the address search engine 150 . The search context is transmitted to a preliminary processing unit 190 within the search engine 150 .
The preliminary processing unit 190 receives the search context. It then requests the hash table entry from a memory 200 using the hash table entry address contained in the search context. The requested hash table entry is then transmitted by the memory 200 to the processing unit 190 . The requested hash table entry contains the address of the first hash bucket header in the MAC address linked list.
The processing unit 190 then modifies the search context by inserting the address of the first hash bucket header in the linked list as part of the search parameters. The search context, containing the modified search parameters, is then transmitted to the data pipeline 210 for buffering and retransmission to a memory request unit s_hbread 220 .
The memory request unit s_hbread 220 extracts the search parameters from the search context received from the data pipeline 210 . The memory request unit s_hbread 220 then requests from the memory 200 the hash bucket header having the address contained in the search parameters. After initiating the memory request, the memory request unit 220 then transmits the search context to the data pipeline 250 for buffering and retransmission to the compare unit s_hpcomp 240 .
The memory request result transmitted to the compare unit s_hpcomp 240 from the memory 200 is a bucket header containing a MAC address and a pointer to the next bucket in the linked list as outlined in the explanation above regarding the hashing procedure.
The compare unit s_hpcomp 240 , once it receives the search context from the data pipeline 250 and the memory request result from the memory 200 pairs the memory request result with the proper search context. To determine if further searching is needed, the compare unit s_hpcomp 240 can receive from outside the module 110 the MAC address being searched. In FIG. 6 the compare unit s_hpcomp 240 receives the MAC address being searched from the header control unit 130 . Once the search context and memory request result have been paired, the compare unit s_hpcomp 240 matches the MAC address being searched, received by the compare unit s_hpcomp 240 from the header control unit 130 , with the MAC address contained in the memory request result. As an alternative to the external input, the MAC address being searched for can also be included in the search context.
If there is a match between the MAC address being searched for and the MAC address contained in the memory request result, then the compare unit s_hpcomp 240 modifies the search context to indicate a successful search. Also, the compare unit 240 inserts in the search context the address of the bucket header with the matching MAC address. This bucket header address with the matching MAC address is later used to retrieve the forwarding context of the MAC address being searched for. The search context is then transmitted to either the data pipeline 260 for reporting or to the data pipeline 280 for an IP longest prefix match. The compare unit 240 determines which data pipeline to transmit the modified search context by checking an IP data flag. This IP data flag can be received from the header control unit 130 along with the MAC address to be searched for or the data flag can be contained in the search context. The IP data flag indicates the presence of an IP data packet. If the flag is set, then the compare unit 240 transmits the modified search context to the data pipeline 280 . If the flag is not set then the compare unit 240 transmits the modified search context to the data pipeline 260 . The use of the IP data flag eliminates the need to determine whether the MAC address being searched for is a source or a destination MAC address. If the IP data flag is set, this is the only condition when the modified search context is transmitted to the data pipeline 280 .
If, on the other hand, there is no match between the MAC address contained in the memory request result and the MAC address being searched for, the compare unit 240 extracts the pointer to the next link in the linked list from the bucket header. This pointer is then used to modify the search parameters in the search context. Since the search parameters contain the address of the bucket header to be retrieved from memory, the pointer is used to modify the search parameters such that the next bucket header to be retrieved is the next bucket header in the linked list. After modification of the search parameters within the search context, the modified search context is transmitted to the data pipeline 230 for retransmission to the memory request unit s_hbread 220 where a new memory request will be initiated based on the modified search parameters.
Since the linked list of bucket headers are usually not infinite in length, the situation can arise wherein the MAC address in the bucket header does not match the MAC address being searched for with the linked list being exhausted. In this situation, the compare unit 240 modifies the search context to indicate that the MAC address search was unsuccessful. The modified search context is then transmitted to the data pipeline 260 for reporting the unsuccessful search, regardless of whether the IP data flag is set or not.
When the search context reaches the data pipeline 280 , it has reached the second module 120 . From this point on, the search engine 150 will be executing the modified Gupta et al procedure detailed above to search for an exit port for a specific IP address contained in the search context.
As shown in FIG. 6, second module 120 has a structure almost identical to that of the module 110 . The data pipeline 280 receives and buffers the incoming search contexts and sequentially retransmits the search contexts to the memory request unit s_rtread 270 . From the memory request unit s_rtread 270 , search contexts are transmitted and buffered by the data pipeline 310 . From the data pipeline 310 , search contexts are transmitted to the compare unit s_rpcomp 320 .
Depending on the results of the comparison at the compare unit s_rpcomp 320 , search contexts are then transmitted to either the data pipeline 290 for a further search or to the data pipeline 330 for reporting.
To fully understand the workings of the module 120 , one must follow a search context through the module. Assuming that a MAC address search was successful and that the IP data flag indicated the presence of an IP data packet, the search context is received by the data pipeline 280 from the compare unit 240 of the module 110 . The data pipeline 280 then transmits the search context to the memory request unit s_rtread 270 .
The memory request unit s_rtread 270 , when the search context is initially received, extracts the IP address contained within the search parameters. Once this is accomplished, the most significant 17 bits of the IP address are extracted further, in accordance with the first steps of the modified Gupta procedure as outlined above. These 17 most significant bits of the IP address are added to a predetermined base address of a first route table RT 0 to form a complete memory address of a selected entry in the first route table.
The memory request unit s_rtread 270 then initiates a memory request for the selected entry in the first route table using the complete memory address obtained.
The search context is then transmitted from the memory request unit s_rtread 270 to the data pipeline 310 for buffering and eventual retransmission to the compare unit s_rpcomp 320 .
The compare unit s_rpcomp 320 determines whether further searching is needed after it receives a result from the memory 200 of the memory request initiated by the memory request unit s_rtread 270 . Based on the contents of this result and the contents of the search context, the compare unit s_rpcomp 320 modifies the contents of the search context accordingly and transmits the modified search context to either the data pipeline 290 for further searching or the data pipeline 330 for reporting.
The compare unit s_rpcomp 320 examines the result in conjunction with the search context and the search parameters contained within the seach context. Since the result is an entry in the route table as outlined in the explanation of the modified Gupta et al procedure, the entry will have the format illustrated in FIG. 2 . The compare unit s_rpcomp 320 checks both the INDIRECT bit 64 and the valid bit 62 in the route table entry along with the value in the counter that details which step in the modified Gupta procedure is being executed. If the VALID bit 62 is not set, then the search terminates and the compare unit 320 modifies the search context to indicate that the IP address for which an exit port is being sought is an invalid address.
As noted in the explanation of the modified Gupta procedure above, if the INDIRECT bit 64 is set, then more searching is needed. A set INDIRECT bit 64 means that the address contained in the route table entry must be used as a pointer into the next route table.
If the compare unit s_rpcomp 320 determines that the IP address search is successful, that is if the VALID bit is set and the INDIRECT bit is not set, then the address contained in the route table entry received is to be used as a pointer to a route context table entry. The compare unit then copies the address contained in the route table entry to the search context. Also, the compare unit sets a flag within the search context which indicates to the reporting module 125 that the IP search was successful.
The decision table below (Table 1) sets out the actions of the compare unit s_rpcomp 320 given different conditions.
TABLE 1
Condition (s_rpcomp unit)
Operation
Valid bit NOT set
Invalid route table entry encountered, write
search context to the data pipeline 330
for reporting of the invalid condition
INDIRECT bit set and
More searching required.
current step counter < 2
Transmit modified context to data pipeline
(this means that the unit
290
has not received a route
table 2 entry)
Current step counter = 2
Maximum number of searches reached, no
(this means that the unit
more searching possible. Ignore the
has received a route table
INDIRECT bit and transmit modified
2 entry
search context to data pipeline 330
INDIRECT bit not set
Look up hit at this step.
Write modified search context to
data pipeline 330
Thus, from the table, if both the VALID and INDIRECT bits are set and the current step counter is less than 2, then the compare unit s_rpcomp 320 modifies the search context and transmits the modified search context to data pipeline 290 .
The compare unit s_rpcomp 320 modifies the search context by incrementing by one the current step counter in the search context. It then transmits the modified search context to data pipeline 290 . The data pipeline 290 then buffers and retransmits the modified search context to the memory request unit s_rtread 270 .
The memory request unit 270 , (after receiving the modified search context from data pipeline 290 ), uses the value of the current step counter contained within the search context to determine its actions. Since the module 120 implements the modified Gupta et al procedure, three route tables, RT 0 , RT 1 and RT 2 may be accessed along with 3 different base addresses and 3 different parts of the IP address to be extracted to formulate the complete memory address with the memory request to be initiated. The table below (Table 2) details the actions of the memory request unit 270 depending on the value of the current step counter.
TABLE 2
Current Step
Counter Value
Action
0
a) extract 17 most significant bits
(this means that the
(MSB17) of IP address
search is a brand
b) add MSB17 to the predetermined base address
new IP search)
of route table RT0
1
a) Extract next 8 most significant bits (8MSB) of
IP address
b) concatenate 8MSB with the index/pointer con-
tained in the route table entry and the
predetermined base address of route table RT1
2
a) Extract the 8 least significant bits (8LSB) of
IP address
b) concatenate 8LSB with the index/pointer
contained in route table entry and with the
predetermined base address of route table RT2
Then, after any of the actions listed above, the memory request unit 270 uses the complete address formulated according to Table 2 to initiate a memory request. The modified search context is then transmitted to the data pipeline 310 for buffering and retransmission to the compare unit s_rpcomp 320 .
The memory request unit s_rtread 270 can also receive search contexts and hence search requests from outside the module 120 . As can be seen from FIG. 6, the memory request unit s_rtread 270 can receive an auxiliary search request from an external source. Such an external request would comprise a search context with all the necessary search parameters.
Should the particular database lookup procedure being implemented require it, the IP address can be made available to the compare unit s_rpcomp 320 from the header control unit 130 . This extra input line into the compare unit s_rpcomp 320 is illustrated in FIG. 6 . Such a line can be used to double-check the integrity of the IP address in the search context.
The reporting module 125 receives the search contexts of completed searches from both modules 110 and 120 . As can be seen from FIG. 6, a memory request unit s_fetchresult 340 receives the search contexts of completed searches from the data pipelines 330 and 260 . The memory request unit s_fetchresult 340 is, along with a reporting unit 350 , within the reporting module 125 .
Once the memory request unit s_fetchresult 340 receives a search context of a completed search, it determines whether a memory request is required or not. If the search context indicates an unsuccessful search, because of either an invalid IP address or a MAC or IP address that could not be found, the memory request unit s_fetchresult 340 transmits the search context to the reporting unit 350 via the data pipeline 360 .
If, on the other hand, the search context indicates a successful search, the memory request unit s_fetchresult 340 determines what type of memory request to initiate. If the successful search was for an IP address, then the memory request unit s_fetchresult 340 initiates a memory request for not only the entry in the route context table RC for the IP address, but also for the forwarding context of the MAC address matched. If the successful search was simply for a MAC address, the forwarding context contained in the matched hash bucket will be retrieved. It should be remembered that the compare unit s_rpcomp 320 inserted the address contained in the route table entry in the search context once the compare unit s_rpcomp 320 had determined that the INDIRECT bit was not set. It should also be remembered that the compare unit s_hpcomp 240 had written in the search context the address of the bucket header with a MAC address which matched the MAC address being sought.
Thus the reporting module 125 retrieves both the route context of the IP address contained in the search context by having the memory request unit s_fetchresult 340 request the entry in the route context table using the pointer contained in the search context to request the rest of the hash bucket from the memory 200 .
After the memory request unit s_fetchresult 340 initiates the relevant memory requests, it transmits the search context to the data pipeline 360 . The data pipeline 360 then buffers and eventually transmits the search context to the reporting unit 350 .
The reporting unit 350 receives the results of the memory requests initiated by the memory request unit s_fetchresult 340 from the memory 200 .
If the search context received by the reporting unit s_reports 350 indicates an unsuccessful search, the reporting unit transmits an indication of both the unsuccessful search and the search identifier to circuitry 400 outside the search engine 150 .
If the search context received by the reporting unit s_report 350 indicates a successful search, the reporting unit s_report 350 matches the search context received with the memory result transmitted from the memory 200 . The reporting unit s_report 350 then transmits both the indication of the successful search and the results of that search, received from the memory 200 , to circuitry 400 outside the search engine 150 .
It should be noted that while the embodiment illustrated here is a hardware implementation of the invention, a software implementation is also possible. | An apparatus for executing a multiple step database lookup procedure, the apparatus including a plurality of processing units, at least two processing units being coupled to a memory containing a database to be looked up, and a plurality of data pipelines which couple the plurality of processing units to each other and to external apparatus, wherein each processing unit executes at least one step in the multiple step database lookup procedure. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to U.S. Provisional Application Ser. No. 60/561,494, filed on Apr. 13, 2004, and is a continuation in part of application Ser. No. 11/105,247, filed Apr. 13, 2005, entitled Rattle For Attracting Fish.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates in general to the field of fishing rattles and in particular to rattle to attract fish which rattle can be used alone or in combination with a fishing lure.
[0004] 2. Description of the Prior Art
[0005] Fishermen using a pole and fishing line have for many years sought ways to better their chances of catching fish. It is known that fish have a lateral line on their body that responds to sound. Accordingly, devices have been advanced in the prior art to use the sound responding lateral line to attract fish and help catch them. These prior art devices have involved myriad technologies including electronic generation of various sounds and simple beads within a tube that emit a clicking noise when shaken. The general consensus in the fishing sport and industry is that the use of sound does indeed attract fish. The prior art sound producing devices are used with hard fishing lures such as crank baits, spoons, etc. and soft fishing lure such as plastic worms , crawdads, frogs, and other artificial baits that fish are known to eat.
[0006] One prior art rattle is used with a bullet shaped weight attached to a soft plastic artificial lure as seen in U.S. Pat. No. 5,381,622. In this prior art device, a sleeve is incorporated within the body of the bullet weight. The forward and aft ends of the sleeve is provided with a cap. A cylindrical weight that is configured to slide on the sleeve. When the cylindrical member hits either the forward or aft cap, a clicking sound is generated that can be heard outside of the bullet weight. This particular rattle however requires a generous amount of movement of the weight in order to have the cylindrical member slide on the sleeve the distance needed to strike the end caps. There are disadvantages to the generous movement required to generate the clicking sound. The generous movement must for example, be intentionally caused and usually does not occur when a slight twitching of the rod occurs or when the weight's movement slightly deviates from being pulled in a straight line or when the weight encounters a rock or a weed that causes the weight to deviate from a straight line movement.
[0007] U.S. Pat. No. 5,428,919, by Enomoto, issued Jul. 4, 1995 discloses another type of a sliding annular member imbedded within a sinker that when moved either laterally or vertically, the annular member slides within a water tight air chamber striking one of the inner side walls of the sinker. Depending upon the location of the annular member within the air chamber and lateral movement of the sinker, it is possible that the annular may pivot and strike one inner wall; however, in general and under most conditions the annular will generate a noise by sliding within the air chamber rather than pivoting.
[0008] U.S. Pat. No. 3,848,353, by McClellan, issued Nov. 19, 1974, is another rattle, with an embodiment disclosing a pair of slugs (ordinary threaded nuts) within a chamber formed in a cylindrical member having a conical end. In this invention the slugs roll within the chamber causing one slug to strike one end of the chamber and the other slug strikes the other end of the chamber. In this embodiment, no provision is made to make the chamber water tight.
[0009] In prototype testing, it has been determined that the prior art rattles above noted are generally ineffective in performing their intended purpose. Either the noise produced is to too low or soft to be effectively heard outside the rattle, or the noise produced is intermittent, or the rattle is insufficiently sensitive to generate noise with slight motions of the fishing line.
[0010] Accordingly what is needed is an improvement rattle that emits a clicking sound when an artificial lure, either hard or soft, is slightly moved be it intentionally or during the normal action of the lure as it is pulled through the water or encounters a natural object in the water.
[0011] What is further needed is a rattle that is effective: that emits sufficiently loud noises; and, a rattle that produces more clicks in conjunction with slight movement of the fishing line and operates almost entirely by pivoting an internal weight.
[0012] The present invention is directed to such an improved rattle.
SUMMARY OF THE INVENTION
[0013] The above-stated objects as well as other objects which, although not specifically stated, but are intended to be included within the scope the present invention, are accomplished by the present invention and will become apparent from the hereinafter set forth in this specification, the claims and the drawings presented herein.
[0014] The present invention, in one embodiment comprises a unique rattle that is attachable to a fishing weight, which is sometimes called a sinker, or that is used with a fishing weight, or that is used with an artificial soft or hard fishing lure. The improved and unique rattle includes a hollow cylindrical member capped on both ends with a thin membrane with an annular member located within the hollow cylindrical member. The length of the hollow member in conjunction with the outer diameter of the annular member causes the annular member to strike one side and then the other side end producing a plurality of clicking sounds with slight movement of the fishing line. The slight movement of the rattle causes the annular member to pivot within the hollow cylindrical member and strike either of the cap ends, thereby emitting the clicking sounds. In another embodiment, a small diameter sleeve extends axially within the center of the hollow cylindrical member. In this embodiment, the annular member includes an internal diameter that is sufficiently large such that the sleeve does not interfere with the pivoting action within the hollow cylindrical member.
[0015] In accordance with the above, there has been summarized the more important features of the present invention in order that the detailed description of the invention as it appears in the below detailed description of the same, may be better understood.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawing, in which:
[0017] FIG. 1 illustrates, in cross section, an embodiment of the inventive rattle;
[0018] FIG. 2 illustrates a cross section of FIG. 1 taken through the line 2 - 2 thereof;
[0019] FIG. 3 illustrates, in cross section, the embodiment of FIG. 1 including a sleeve axially positioned within the body of the rattle;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functioning details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Additionally, the verbiage used herein is intended to better enable a person to understand the invention and therefore, such verbiage is not to be interpreted as limiting the invention.
[0021] The details of the improved rattle 10 are shown in FIGS. 1 and 2 . In this embodiment an annular body member 11 which comprises a hollow, substantially cylindrical member, or its equivalent, is fitted with end caps 12 . An annular or ring like member 13 is located within the hollow cylindrical body 11 . Annular member 13 is sized to have an outer diameter somewhat smaller that the internal diameter of the body 11 and such that when the annular member 13 rests vertically at one point against the internal diameter of body 11 . In this manner, the annular member 13 is allowed to pivot at the point it rests against the internal diameter of body 11 without interfering with the internal diameter of body 11 . The length of body 11 is sized such that a slight inclination of the rattle from the position shown in FIG. 1 , allows the annular member 13 to pivot and strike one of the end caps 12 . In practice, the internal length of body 11 , between the end caps 12 , can approximately be between the range of two or more times the thickness of annular member 13 but less than the external or outer diameter of the annular member 13 .
[0022] In prototype testing a length of the internal length of body 11 of approximately three to four times the thickness of annular member has been shown to be satisfactory. The outer diameter of body 11 is not necessarily of any particular size; however, practical considerations of the way the rattle 10 is used either alone or in conjunction with other fishing lure apparatus, bears on the size of the outer diameter of the body 11 as it is used in practice. For example, if the inventive rattle 10 is used with a prior art bullet weight the outer diameter of the rattle 10 or the body 11 is preferably approximately equal to the outer diameter of the bullet weight. If the rattle 10 is to be used in conjunction with an artificial hard lure such as a crank bait, the outer diameter of body 11 and the overall size of the rattle 10 is dictated by the size of the crank bait. The thickness of the wall of the body is also not a factor critical to the invention or its operation; but again, practical considerations will bear on the thickness. For example, the ability to sealingly connect the side caps 12 to body 11 is a practical factor. Body 11 can be configured to integrally include one end cap 12 with the other end cap 12 being sealingly secured to body 11 . Or, both end caps 12 can be sealingly secured to a hollow cylindrical configuration of body 12 . The wall thickness of the hollow member 11 is to be such so that it not readily crushed by ordinary handling; but, it is not be so thick that it causes the annular member to be too small and not generate sufficient noise.
[0023] Annular or ring-like member 13 is preferably to be of the largest size possible consistent with the need to sufficiently pivot and gain sufficient velocity to result in a reasonably loud noise. For example, if the annular member thickness relative to the length of the body member 11 is above 1 to 2, the pivoting velocity will probably be too slow to generate a sufficiently loud noise. Prototype testing has determined that a ratio of annular member thickness to body length below 1:2 and above 1:4 is satisfactory where the outer diameter of the annular member is only slightly smaller than the internal diameter of the body member. The main criteria being its ability to readily pivot within the body 11 when resting on a lower oriented point of the inner diameter of the body 11 and striking one of the end caps 12 .
[0024] Prototype testing has also determined that the annular member be as heavy as possible consistent however with practical concerns such as cost, and labor. This testing has further determined that an ordinary steel annular member such as a washer or a thin nut does not produce a desirably loud noise. Lead is sufficiently heavy as is tungsten.
[0025] In order to aid in the tilting or pivoting movement of the ring-like member 13 , it is preferable, but not necessary that the planer cross sectional configuration of the ring-like member 13 be substantially circular as seen in FIG. 1 . In this regard, any type of rounded surface that comes into contact with the inner diameter of the body member is satisfactory and preferable due to its ability to readily pivot. It is to be remembered that an object of the improved rattle is to be more sensitive to fishing line motion than the prior art. The ability to readily pivot enhances the sensitivity of the rattle. An annular member having a plurality of flats or any such equivalent configuration along its outer diameter will not have the sensitivity of an annular member having a rounded surface.
[0026] In combination with the above stated preferences, it has been determined that the wall thickness of the end caps that comprise the objects struck by the pivoting annular member is an important factor in order to result in satisfactory rattle. A relatively thin wall produces a louder sound than a relative thick wall, all other things being equal. Further, the advantages of a thin wall are markedly decreased should it be in contact with another object.
[0027] In use and operation of the inventive rattle 10 , a slight inclination of the rattle from the position shown in FIG. 1 will cause the annular member 13 to pivot within the body 11 and strike one of the end caps 12 thereby producing a clicking sound. Such inclination can result from the rattle 10 being intentionally or non intentionally moved. For example if the rattle 10 is attached to an end of a fishing line that is attached to a fishing pole, a slight twitching of the fishing pole will result in intentional up and down inclination of the rattle 10 and result in a plurality of clicking noises by the annular member pivoting back and forth striking the end caps 12 each time the pivoting occurs. Or, if the line is being retrieved and the rattle 10 encounters a weed or a rock or other natural object, an unintentional up and down inclination of the rattle will occur and cause the clicking sounds. The above described construction of the inventive rattle 10 and its resulting sensitivity is thusly intended to advantageously use, both the intentional and unintentional movement of the rattle 10 to produce the clicking noises and thereby advantageously attract fish. Prototype testing has shown that due to the unique pivoting construction and operation of the rattle 10 , very slight up and down inclinations will result in the producing of very audible clicking sounds of the type that has been demonstrated to attract fish.
[0028] The sensitivity of the inventive rattle 10 to produce fish attracting noises by slight movements of the rattle and the lure to which it can be attached is advantageous in murky waters as well as clear waters. While fishermen generally prefer to fish in clear water because of the belief that more fish are present in clear water, such belief is not necessarily true or at least some fish will be present in murky water. The sensitivity of the inventive rattle 10 will therefore allow fishermen to fish in murky waters as well as clear water and thereby broaden their scope of fishing and the ability to catch more fish,
[0029] FIG. 3 illustrates, in cross section, the embodiment of FIG. 1 including a sleeve 15 axially positioned within the body 11 of the rattle 10 B and through the end caps 12 . Sleeve 15 allows a fishing line (not shown) to pass through the rattle 10 B. Sleeve 15 is sealingly attached to end caps 12 . In this embodiment 10 of the inventive rattle, the inner diameter of the annular member 13 is sized so as not to interfere with the sleeve 15 or be restricted by the sleeve 15 during the pivoting motion of the annular member 13 . Such sizing knowledge is within that of a person of ordinary skill in the art of the invention.
[0030] While the invention has been described, disclosed, illustrated and shown in certain terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be nor should it be deemed to be limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breath and scope of the drawings and description provided herein. | An improved rattle for attracting fish includes a hollow cylindrical chamber that is sealingly closed by ultra thin end caps. An annular, ring like member is positioned within the closed chamber so as to rest on its edge on the inner diameter of the closed chamber. The chamber diameter is larger than the outer diameter of the annular member thereby allowing the annular member to pivot on its edge when the rattle is rocked back and forth along its axial axis. The length of the chamber is relatively short. The pivoting causes the annular member to strike the sides of the closed chamber thereby producing a type of clicking sound that is known to attract fish. The combination of the ultra thin end caps and short chamber provides for improved loudness and sensitivity to slight motions of the rattle. | 0 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention is related to highway barriers and safety systems and more particularly to cable safety systems and associated posts.
BACKGROUND OF THE INVENTION
[0002] Cable safety systems and cable barriers have been installed along edges of roadways and highways for many years. Cable safety systems and cable barriers have also been installed along medians between roadways and/or highways. Cable safety systems generally include one or more horizontal cables attached to support posts. For some applications cable safety systems and cable barriers may reduce damage to an impacting vehicle and/or injury to occupants of the impacting vehicle as compared with other types of highway safety systems and highway barriers.
[0003] Cable safety systems are often designed and installed with three cables mounted horizontally on a plurality of generally vertical support posts. The number of cables may vary depending on various factors such as the type of vehicles using the associated roadway and the hazard which required installation of the cable safety system. The length of a cable safety system is generally determined based on the adjacent roadside hazard. Each cable is typically installed at a desired height relative to the ground and with a desired spacing between adjacent cables. Associated support posts are installed with desired horizontal spacing between adjacent posts.
[0004] One recognized limitation of cable safety systems is excessive deflection of associated cables during vehicle impact. Deflection associated with a cable safety system may be larger than deflection of a convention W-beam guardrail when subjected to the same type of vehicle impact. Such deflection frequently determines maximum allowed spacing between adjacent posts for satisfactory performance of the cable safety system. Large deflection during a vehicle impact also increases the risk of the vehicle running over the cables and being exposed to the hazard which required installation of the cable safety system.
[0005] From full scale crash testing and from real life experience, it has been determined that keeping the length of unsupported cables as short as possible will generally reduce deflection. The longer the distance between adjacent posts supporting associated cables, the larger the deflection will generally be during a vehicle impact. An increased number of posts (shorter post spacing) will generally decrease deflection. However, shorter spacing between posts affects total cost of a cable safety system, not only material, but also installation cost.
[0006] High-speed films from full-scale crash testing of vehicles with cable safety systems demonstrate that posts installed immediately adjacent to the location of a vehicle impact with unsupported portions of the cables will bend and/or deform in response to forces placed on the posts by the cables. When a post is bent at an angle of about ten (10°) degrees from vertical, the upper cable of a typical three cable safety system will often slide out of its associated slot or hook and lose its retaining capabilities. After another couple of degrees of the post bending from vertical, the second cable will slide out of its associated slot or hook. Finally, the third cable will slide out of its associated slot or hook when the post is bent about twenty eight to thirty (28° to 30°) degrees from normal. When the cables are released from posts adjacent to the point of vehicle impact, deflection of the cables will increase significantly.
[0007] Vertical spacing between cables, vertical spacing of the cables relative to the associated roadway and horizontal spacing between adjacent posts are preferably designed and selected to allow the resulting cable safety system to satisfactorily function during a vehicle impact. Desired vertical spacing between cables and vertical spacing of cables relative to the ground may be obtained in a number of ways by using spacers, hooks, straps or other devices. The number of times an installer has to go to each post is of major concern since this not only takes time, but more importantly, exposes installers to the risk of being injured by traffic. Additional care must be taken with respect to design and installation of cable safety systems adjacent to curves in a highway or roadway and adjacent to inclines or slopes.
[0008] During the past several years, cable safety systems have been used as an alternative to traditional W-beam guardrail systems. These cable safety systems address some of the weaknesses of prior cable safety systems by using pre-stressed cables and/or reducing the spacing between adjacent posts to reduce deflection to an acceptable level. A consultant report “Dynamic Analysis of Cable Guardrail” issued in April 1994 by an ES-Consult in Denmark, established a model for which parameters affect performance and designing desired deflection of cable safety systems.
SUMMARY OF THE INVENTION
[0009] In accordance with particular embodiments of the present disclosure, the disadvantages and problems associated with cable guardrail safety systems have been substantially reduced or eliminated.
[0010] In accordance with particular embodiments of the present disclosure, a safety barrier comprises a plurality of posts spaced from each other and disposed adjacent to a roadway, each post having a cross section defined in part by a web and a pair of legs extending therefrom. Additionally, each post has one slot formed in the web of the post extending from an upper end of the post. The safety barrier further comprises a first cable and a second cable releasably engaged with and supported by the posts and disposed within each slot between the respective legs of each post. The safety barrier further comprises a third cable and a fourth cable each coupled to an exterior surface of the posts. Each slot has a first edge and a second edge with respective sloping surfaces operable to slid ably receive the first cable and the second cable therein. The sloping surfaces on the first edge of each slot provide a first projection and the sloping surfaces on the second edge of each slot provide a second projection. The posts and the first, second, third and fourth cables cooperate to prevent a vehicle from leaving the roadway.
[0011] In accordance with another embodiment of the present disclosure, a post for installing a cable safety system comprises a cross section defined in part by a web and a pair of legs extending from the web. The post also comprises a first end and a second end with a slot formed in the web starting at the first end an extending partially along the length of the post, the second end configured to be installed adjacent to a roadway. The slot has a first edge and a second edge and is sized to receive a first cable and a second cable therein. The post further comprises at least one restriction defined in part by respective sloping surfaces formed on each edge of the slot to increase retention time of the first cable and the second cable within the slot as the post is bent from a generally vertical position during a vehicle impact with the cables disposed within the slot. The post also comprises a first fastener coupled to a first exterior surface of the post, the first fastener size to receive a third cable and a second fastener coupled to a second exterior surface of the post, the second fastener sized to receive a fourth cable. The post also comprises at least one spacer disposed within the cross section of the post operable to maintain the cables at a desired spacing within the slot.
[0012] In accordance with yet another embodiment of the present disclosure, a method of installed a cable safety system comprises forming a plurality of posts with each post having a slot extending from an upper end of the post. The method also includes forming the slot with a first edge and a second edge. Additionally, the method includes forming respective tapered surfaces on the first edge to provide a first projection and forming respective tapered surfaces on the second edge to provide a second projection. The method also includes forming at least one restriction within each slot defined in part by the first projection extending from the first edge and the second projection extending from the second edge to increase retention of the cables within the slot as the respective posts are bent from a generally vertical position. The method further includes installing the plurality of posts spaced from each other proximate to the roadway. The method further includes releasably engaging a first cable and a second cable within the respective slot formed in each of the posts and coupling a third cable and a fourth cable to an exterior surface of the posts.
[0013] In accordance with yet another embodiment of the present disclosure, a method for manufacturing a support post for a cable safety system comprises forming a post with a first end and second end. The method also includes forming the post with a cross section defined in part by a web and a pair of legs extending therefrom. The method also includes forming a slot in the web extending from the first end of the post and forming the slot with a first edge and second edge. The method further includes forming respective tapered surfaces on the first edge to provide a first projection and respective tapered surfaces on the second edge to provide a second projection, the first projection extending from the first edge and the second projection extending from the second edge to increase retention of a first cable and a second cable in the slot as the post bends from a generally vertical position during a vehicle impact with the cable safety system. The method also includes forming at least one spacer disposed within the cross section of the post operable to maintain at least a first cable and a second cable at a desired spacing within the slot.
[0014] Technical advantages provided by particular embodiments of the present disclosure include providing a cable safety system that maintains engagement between posts and associated cables for a longer period of time as the posts are bent from a generally vertical position during a vehicle impact. A cable safety system incorporating teachings of the present invention also minimizes the number of times an installer has to go to each post to position associated cables at desired heights relative to each other and an adjacent roadway. The present invention reduces both the cost and the time required to install a cable safety system.
[0015] Technical advantages provided by particular embodiments of the present disclosure further include enabling cables and a metal portion of a support post to interact more quickly. This enables vehicles be more effectively redirected away from away from hazardous areas by enabling cables to provide resistance to vehicles impacting cable safety system sooner after impact.
[0016] Moreover, because of the innovative support post, a support post may be manufactured at a reduced cost compared with previous designs. In particular, the inclusion of four cables in cable safety system allows for a shorter overall height of support post. The inclusion of an additional cable connected to the support post at an appropriate height enables the top-most cable to be positioned higher relative to ground level than previous systems. A higher overall cable height enables a support post to be shorter overall. Additionally, the inclusion of four cables allows for the use of a thinner web in support post. Further, a cable safety system may be manufactured without punching holes in the bottom of support post, which may substantially reduces the manufacturing cost of support post.
[0017] In combination with four cables and other aspects of cable safety system, the smaller and thinner size of support post is effective to improve redirection of vehicles away from hazardous areas without causing serious injuries to the vehicle's occupants or other motorists. A smaller post in combination with a three-cable design would not have performed as effectively because a three-cable design may be less effective at preventing vehicles from summarizing or passing through cable safety system as compared to a four-cable design. A combination of a smaller and thinner support post may enable a support post to be manufactured at a weight of 5.7 pounds per foot, compared with a weight of 7.7 pounds per foot for previous designs, thereby enabling substantial cost savings during manufacture and maintenance.
[0018] As a result, particular embodiments of the present disclosure may provide numerous technical advantages. Particular embodiments the present disclosure may provide some, none, all, or additional technical advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A more complete and thorough understanding of the present invention and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
[0020] FIG. 1 a is a schematic drawing in elevation with portions broken away of a cable safety system incorporating teachings of the present invention;
[0021] FIG. 1 b is a schematic drawing showing a plan view with portions broken away of the cable safety system of FIG. 1 a;
[0022] FIG. 1 c is a schematic drawing in elevation with portions broken away of another cable safety system incorporating teachings of the present invention;
[0023] FIG. 1 d is a schematic drawing in section and in elevation with portions broken away of a below ground cable anchor assembly satisfactory for use with the cable safety system of FIG. 1 c;
[0024] FIG. 2 is a schematic drawing in section showing one example of a cable satisfactory for use in forming a cable safety system incorporating teachings of the present invention;
[0025] FIG. 3 is a schematic drawing in elevation with portions broken away showing one example of a post and attached cables incorporating teachings of the present invention;
[0026] FIG. 4 is a schematic drawing taken along lines 4 - 4 of FIG. 3 ;
[0027] FIG. 5 is an enlarged schematic drawing showing an isometric view with portions broken away of a post and cables incorporating teachings of the present invention;
[0028] FIG. 6 is a schematic drawing showing an isometric view of one example of a spacer incorporating teachings of the present invention;
[0029] FIG. 7 is a schematic drawing showing one method for installing the spacer of FIG. 6 with the post and cables of FIG. 5 ;
[0030] FIG. 8 a is a schematic drawing in section and in elevation showing one example of the results of a vehicle impacting a cable safety system;
[0031] FIG. 8 b is a schematic drawing in section and in elevation showing one example of the results of a vehicle impacting a cable safety system incorporating teachings of the present invention;
[0032] FIG. 9 is a schematic drawing in elevation with portions broken away showing another example of a post formed in accordance with teachings of the present invention;
[0033] FIGS. 10A-10I are schematic drawings in section showing further examples of posts incorporating teachings of the present invention;
[0034] FIG. 11 is a schematic drawing of a particular embodiment of cable safety system utilizing four cables;
[0035] FIGS. 12B and 12B is a schematic drawing showing a particular embodiment of a support post utilized in certain embodiments of a cable safety system; and
[0036] FIGS. 13A and 13B show schematic views of slots positioned in a support post, in accordance with particular embodiments of the present disclosure.
DETAILED DESCRIPTION
[0037] Preferred embodiments of the invention and its advantages are best understood by reference to FIGS. 1A-13B wherein like reference numbers indicate like features.
[0038] The terms “safety system or systems” and “barrier or barriers” are used throughout this application to describe any type of safety system and/or barrier which may be formed in accordance with teachings of the present disclosure. The term “roadway” is used throughout this application to include any highway, roadway or path satisfactory for vehicle traffic.
[0039] Various aspects of the present disclosure will be described with respect to cable safety system 20 . However, teachings of the present disclosure may be used to form a wide variety of cable safety systems and cable barriers. The present disclosure is not limited to cable safety system 20 as shown in FIGS. 1 a - 1 d.
[0040] Cable safety systems incorporating teachings of the present disclosure may be used in median strips or shoulders of highways, roadways or any other path which is likely to encounter vehicular traffic. The present disclosure may be used to form a wide variety of safety systems and barriers installed on a median between roadways and/or along the edge of a roadway. Cable safety system 20 may be installed adjacent to a roadway to prevent motor vehicles (not expressly shown) from leaving the roadway and to redirect vehicles away from hazardous areas without causing serious injuries to the vehicle's occupants or other motorists. The direction of traffic flow along the roadway is illustrated by directional arrow 22 .
[0041] Cable safety system 20 preferably includes a plurality of support posts 30 anchored adjacent to the roadway. Posts 30 may be anchored with the ground using various techniques. The number, size, shape and configuration of posts 30 may be significantly modified within teachings of the present disclosure. A plurality of cables 60 a, 60 b and 60 c may be attached to support posts 30 in accordance with teachings of the present disclosure. Support posts 30 support and maintain associated cable 60 a, 60 b and 60 c in a substantially horizontal position extending along an edge of the roadway. The length of cables 60 a, 60 b and 60 c may be up to 3,000 meters between anchors 22 and 24 . For other applications the length of cable 60 a, 60 b and 60 c may exceed 3,000 meters without an intermediate anchorage. Support posts 30 also maintain desired vertical spacing between cables 60 a, 60 b and 60 c and desired vertical spacing of each cable relative to the ground. Cable safety system 20 including support posts 30 satisfy the criteria of CHIRP Report 350 including Level 3 requirements.
[0042] Cable safety system 20 may be described as a flexible, substantially maintenance free system with designed low deflection of cables 60 a, 60 b, and 60 c during a vehicle impact. Support posts 30 preferably include a “rounded” and “soft” profile with cables 60 a, 60 b and 60 c placed within respective posts 30 . Forming cables safety system 20 in accordance with teachings of the present disclosure minimizes damage during a vehicle impact with cables 60 a, 60 b and 60 c. In some embodiments, cable safety system 20 includes three cables 60 a, 60 b and 60 c disposed in slot 40 of each post 30 . Cable 60 a, 60 b and 60 c are preferably disposed at different heights relative to the ground and relative to each other. Varying the vertical spacing between cables 60 a, 60 b and 60 c provides a much wider lateral catch area for vehicles impacting with cable safety system 20 . The vertical spacing between cables 60 a, 60 b and 60 c may be selected to satisfactorily contain both pickups and, to some extent, even larger vehicles with a relatively high center of gravity, as well as vehicles with a low front profile and low center of gravity. Cable safety system 20 may be satisfactorily used as a median, a single barrier installation along the edge of a roadway and at merge applications between adjacent roadways. For some applications cable safety system 20 may satisfactorily withstand a second impact before repairs have been made after a first impact.
[0043] Various types of cables and/or wire ropes may be satisfactorily used to form a cable safety system in accordance with teachings of the present disclosure. Cables 60 a, 60 b and 60 c may be substantially identical. However, for some applications each cable of a cable safety system formed in accordance with teachings of the present disclosure may have different characteristics.
[0044] Cables 60 a, 60 b and 60 c may be prefabricated in approximately three hundred (300) meter lengths with desired fittings (not expressly shown) attached with opposite ends of each cables 60 a, 60 b and 60 c. Tailor-made cables 60 a, 60 b and 60 c may then be delivered to a desired location for installation adjacent to a roadway.
[0045] Alternatively, cables 60 a, 60 b, and 60 c may be formed from a single cable stored on a large drum (not expressly shown). Cables stored on drums may often exceed three thousand (3,000) meters in length. Cables 60 a, 60 b, and 60 c may be cut in desired lengths from the cable stored on the drum. Appropriate fittings (not expressly shown) may be swaged or otherwise attached with opposite ends of the respective cable 60 a, 60 b and 60 c at an onsite location.
[0046] For some applications cable 60 may be formed from three groups of seven strands of wire rope. Cable 60 may have a modulus of elasticity of approximately 8,300 kg per square mm. The diameter of each strand used to form cable 60 may be approximately 3 mm. The diameter of cable 60 may be approximately 19 mm. Cables 60 a, 60 b and 60 c may be pre-stressed to approximately fifty percent (50%) of their designed or rated breaking strength. Cables 60 a, 60 b and 60 c may be installed between anchors 24 and 26 with approximately twenty thousand Neutrons of tension over a length of approximately three thousand (3,000) meters.
[0047] FIG. 1 d shows one example of a below ground anchor which may be satisfactorily used with a cable safety system incorporating teachings of the present invention. Respective holes 27 may be formed in the ground at desired locations for anchors 24 a and 26 a. A portion of each hole 27 may be filled with concrete foundation 28 . Anchor plate 29 may be securely engaged with concrete foundation 28 using various types of mechanical fasteners, including, but not limited to, a plurality of bolts 23 and nuts 24 . Anchor plate 29 may be formed at an appropriate angle to accommodate the design of cable safety system 20 a. Also multiple slots and/or openings (not expressly shown) may be formed in anchor plate 29 to receive respective end fittings 64 .
[0048] For the embodiment of the present invention as shown in FIG. 1 d, end fitting 64 a of cable 160 a is shown engaged with anchor plate 29 . Various types of anchor assemblies and cable end fittings may be satisfactorily used with a cable safety system incorporating teachings of the present invention. The present invention is not limited to anchor 24 a or end fittings 64 a as shown in FIG. 1 d.
[0049] One example of support posts 30 and cables 60 a, 60 b and 60 c which may be satisfactorily used to form cable safety system 20 in accordance with teachings of the present disclosure is shown in FIGS. 3 , 4 and 5 . Post 30 includes first end 31 and second end 32 . For this embodiment of the present disclosure, post 30 has a generally C-shaped cross section defined in part by web 34 with respective legs 35 and 36 extending therefrom. As best shown in FIGS. 5 and 7 , the extreme edge of each leg 35 and 36 opposite from web 34 are preferably bent inward to eliminate any sharp edges. For some applications post 30 may be formed using roll forming techniques. For some applications second end 32 may be installed in a concrete foundation or footing 100 such as shown in FIGS. 8 a and 8 b . Alternatively second end 32 may be inserted directly into the ground. One or more soil plates (not expressly shown) may be attached to post 30 proximate second end 32 when post 30 is installed directly into the ground adjacent to a roadway.
[0050] Slot 40 is preferably formed in web 34 extending from first end 31 towards second end 32 . The length of slot 40 is selected in part based on the desired vertical spacing of cable 60 c relative to the adjacent roadway. The length of slot 40 is also selected to accommodate the number of cables which will be installed therein and desired vertical spacing between each cable. Slot 40 may have a generally elongated U-shaped configuration defined in part by first edge 41 , second edge 42 and bottom 43 . For the embodiment of the present disclosure as shown in FIGS. 3-5 , first edge 41 and second edge 42 have a generally smooth profile and extend generally parallel with each other. In some embodiments, forming slot 40 within web 34 of post 30 may eliminate bolts, hooks or other mechanical attachments formed on the exterior thereof.
[0051] For some applications post 30 may be formed from metal sheet having a thickness of 4 mm, a length varying approximately from 700 mm to 1,600 mm, and a width of approximately 350 mm. The metal sheet may weigh approximately 7.8 kg per meter. For other applications post 30 may be formed from a metal sheet having a thickness of 4 mm, a length varying approximately from 700 mm to 1,600 mm, a width of approximately 310 mm and a weight of less 4.5 kg per meter. Post 30 may be installed adjacent to a roadway by either driving directly into the soil adjacent to the roadway or by placing end 32 of post 30 in a concrete foundation. See FIGS. 8 a and 8 b . For other applications a foot plate (not expressly shown) may be attached to second end 32 of post 30 for use in bolting or otherwise securely attaching post 30 with a larger foot plate (not expressly shown) cast into a concrete foundation or similar structure adjacent to a roadway.
[0052] For some applications cap 50 may be placed on first end 31 of post 30 . Retaining band 52 may be placed on the exterior of post 30 to provide additional strength. Retaining band 52 may be formed from various types of metals and/or composite materials. For some applications retaining band 52 may be formed from a relatively strong steel alloy to provide additional support to allow post 30 to handle side impact forces on edges 41 and 42 from cables 60 a, 60 b and 60 c during a vehicle impact.
[0053] During installation of cable safety system 20 , cable 60 c may be disposed within slot 40 resting on bottom 43 thereof. Since post 30 has a generally closed cross section defined in part by the bent edges of legs 35 and 36 , a relatively simple first spacer block 46 may be inserted or dropped into post 30 to rest upon cable 60 c. Block 46 may have a generally rectangular configuration with a thickness satisfactory for insertion within the cross section of post 30 . For some applications spacer block 46 may be formed from recycled material. The height of spacer block 46 is selected to correspond with the desired vertical spacing between cable 60 c and 60 b.
[0054] Cable 60 b may then be inserted into slot 40 after spacer block 46 has been disposed on cable 60 c. Second spacer block 48 may then be installed within post 40 with one end resting on cable 60 b opposite from spacer block 46 . The height of second spacer block 48 is preferably selected to correspond with the desired vertical spacing between cables 60 b and 60 a. Spacer block 48 may be formed from recycles material.
[0055] Cable 60 a may then be installed within slot 30 resting on spacer block 48 opposite from cable 60 b. One or more retaining bands 52 may be secured with the exterior of post 40 between cables 60 a and 60 b and/or cables 60 b and 60 c. Cap 50 may then be placed over first end 31 of post 30 .
[0056] FIG. 6 shows a single spacer 146 which may be satisfactorily used to position cable 60 a, 60 b and 60 c at a desired vertical spacings relative to each other within slot 40 . For the embodiment of the present disclosure as shown in FIG. 6 , spacer 146 has a generally I-shaped configuration. Recesses 160 a and 160 c may be formed in opposite ends of spacer 146 . Another recess 160 b may be formed in one edge of spacer 146 intermediate the ends thereof. The dimensions of recess 160 a, 160 b and 160 c are selected to accommodate cable 60 a, 60 b and 60 c. The distance between recess 160 a, 160 b and 160 c are selected to correspond with the desired vertical spacing between corresponding cable 60 a, 60 b and 60 c.
[0057] Spacer 146 may be formed from a wide variety of materials including polymeric materials, elastomeric materials, recycled materials, structural foam materials, composite materials, wood and/or lightweight metal alloys. For some applications spacer 146 may be formed from recycled rubber and/or other recycled plastic materials. The present invention is not limited to forming spacer 146 from any specific type of material or with any specific dimensions or configurations.
[0058] Typical installation procedures for a cable safety system incorporating teachings of the present invention includes installing posts 30 along with anchors 24 and 26 or anchor 24 a and 26 a at desired locations adjacent to a roadway and/or median (not expressly shown). Cables 60 a - 60 d may be rolled out and placed on the ground extending generally longitudinally between anchors 24 and 26 or anchors 24 a and 26 a. Spacers 146 , retaining bands 52 and end caps 50 may also be placed adjacent to each post 30 as desired for the specific installation. Cables 60 a - 60 d may include prefabricated fittings satisfactory for engagement with anchors 24 and 26 or anchors 24 a and 26 a. Alternatively, appropriate fittings (not expressly shown) may be attached with each end of respective cables 60 a - 60 d.
[0059] One end of each cables 60 a - 60 d may be connected with a respective first anchor. Appropriate tension may then be applied to each cable 60 a - 60 d corresponding to a value of approximately 95% of the desired tension depending upon anticipated ambient temperature and other environmental conditions. Each cable 60 a - 60 d may then be marked, cut and an appropriate fitting attached. The other end or the second end of each cable may then be coupled with a respective second anchor. Conventional procedures may be used to adjust the tension in cables 60 a - 60 d to the desired values. Appropriate spacers 146 may then be inserted within each post 30 . Retaining bands 52 and end caps 50 may then be attached to each post.
[0060] For some applications, cable 60 a, 60 b and 60 c may be attached with anchor 24 and extended horizontally through each slot 40 formed in the associated support post 30 . A respective spacer may then be inserted into each support post 30 to provide desired vertical spacing between cables 60 a, 60 b and 60 c. FIG. 7 is a schematic drawing which shows one example of installing spacer 146 within post 30 after cables 60 a, 60 b and 60 c have been placed within slot 40 .
[0061] FIG. 8 a is a schematic drawing which shows the results of a vehicle impact with cables 60 a, 60 b and 60 c adjacent to post 30 . The force of the impacting vehicle will tend to bend post 30 from a generally vertical position towards a horizontal position. As previously noted, cables 60 a, 60 b and 60 c will tend to slide from or be released from associated slot 40 as the angle of bending of post 30 from a vertical position increases. One aspect of the present disclosure includes forming one or more restrictions within each slot to help retain associated cables within the slot when a vehicle impacts the associated safety barrier. For example, support post 30 a is shown in FIG. 8 b with cable 60 a, 60 b and 60 c retained within slot 40 a by restrictions formed along edges 41 a and 42 a. As a result of the restrictions formed within slot 40 a, cables 60 a, 60 b and 60 c will be retained within slot 40 a when post 30 a is bent at the same angle from vertical as post 30 . See FIG. 8 b.
[0062] FIG. 9 is an enlarged schematic drawing showing post 30 a having slot 40 a form thereon with a plurality of restrictions and/or projections formed in each edge 41 a and 42 a. For the embodiment of the present disclosure as shown in FIG. 9 the location and configurations of the restrictions formed in edges 41 a and 42 a are selected to correspond generally with the desired location for associated cables 60 a, 60 b and 60 c.
[0063] FIGS. 10 a - 10 i are schematic drawings showing various cross sections for support posts incorporating teachings of the present disclosure. Post 130 a, 130 c, 130 d, 130 f, 130 g and 130 h do not have any sharp edges exposed to vehicle traffic traveling along an adjacent roadway. Slots 40 may be formed in each post 130 a - 130 h to receive respective cables therein.
[0064] FIG. 11 is a schematic drawing of a particular embodiment of cable safety system 20 utilizing four cables 60 to improve the prevention of motor vehicles from leaving the roadway and the redirection of vehicles away from hazardous areas without causing serious injuries to the vehicle's occupants or other motorists. In particular, cables 60 a, 60 b, 60 c, and 60 d of cable safety system 20 may prevent or reduce the likelihood of a low profile vehicle passing under cable safety system 20 in the event of an impact, while also minimizing the risk of higher-profile vehicles from passing over or through cable safety system 20 . The use of four cables 60 provides numerous advantages, including enabling a shorter and thinner support post 30 design, as well as enabling the cost-effective capture of more and varied types of vehicles upon impact with cable safety system 20 .
[0065] FIGS. 12A and 12B are schematic drawing showing a particular embodiment of support post 30 b utilized in certain embodiments of cable safety system 20 . FIG. 12 shows support post 30 b that accommodates four cables 60 (cables 60 a, 60 b, 60 c, and 60 d ). Cables 60 a and 60 b are positioned in slot 40 b. As previously noted, cables 60 a and 60 b will tend to slide from or be released from associated slot 40 as the angle of bending of post 30 from a vertical position increases. One aspect of the present disclosure includes forming one or more restrictions within each slot to help retain associated cables within the slot when a vehicle impacts the associated safety barrier. For example, support post 30 b is shown in FIG. 12A and 12B with cable 60 a and 60 b retained within slot 40 b by restrictions formed along edges 41 b and 42 b. As a result of the restrictions formed within slot 40 b, cables 60 a and 60 b will be retained within slot 40 b when support post 30 b is bent at the same angle from vertical as support post 30 b.
[0066] FIGS. 12A and 12B also show a particular embodiment of support post 30 b in which cables 60 c and 60 d are positioned on the outside of support post 30 b using fastener 38 . Fastener 38 may represent an eye bolt, hook bolt, or other suitable retainer for cable 60 . In an installed configuration, cable 60 c may be positioned on the side of support post 30 b closest to the roadway. Cable 60 d may be positioned on the opposite of support post 30 b on which cable 60 c is installed. That is, cable 60 d may be positioned on a side of support post 30 b closest to a median between roadways. For example, cable safety system 20 may be installed on or near a median between a southbound roadway and a northbound roadway. Cable 60 c is advantageously positioned on support post 30 b to prevent or reduce the likelihood of a northbound vehicle on the northbound roadway from crossing into the median upon impact with cable safety system 20 , and heading into southbound traffic on the southbound roadway. Cable 60 d is advantageously positioned on support post 30 b to prevent or reduce the likelihood of a southbound vehicle on the southbound roadway from submarining, or passing under, cable safety system 20 and heading into northbound traffic.
[0067] Cables 60 a, 60 b, 60 c, and 60 d may be advantageously positioned along relative heights of support post 30 b to minimize the risk of vehicles passing over, under, or through cable safety system 20 . In particular, from the lowest cable to the highest cable, cable 60 d may be positioned approximately one foot, six inches (1′-6″) from ground level. Cable 60 c may be positioned approximately two feet, six inches (2′-6″) from ground level. Cable 60 b may be positioned approximately three feet, two inches (3′-2″) from ground level. Cable 60 a may be positioned approximately three feet, six inches (3′-6″) from ground level. Advantageously placing cables 60 along these relative vertical positions of support post 30 b may prevent or reduce the likelihood of lower-profile vehicles, such as subcompact cars, from submarining, or passing under, cable safety system 20 . Further, higher-profile vehicles, such as pickup-trucks and vans, may be prevented from passing over, or through cable safety system 10 .
[0068] FIGS. 13A and 13B show schematic views of slots 40 a and 40 b positioned in support posts 30 a and 30 b, respectively. FIG. 13 a shows slot 40 a suitable for use in a three-cable cable safety system 20 . Slot 40 a accommodates cables 60 a, 60 b and 60 c. In particular embodiments, slot 40 a may be open at a top end, positioned at the top of post 30 a, and may have an overall length of eleven and thirteen sixteenths inches (11 13/16″). Slot 40 a may be one and three-eighths inches (1⅜″) wide at its widest extent, and may include three restrictions formed along edges 41 a and 42 a that are each thirteen sixteenths inches ( 13/16″) wide. As shown in FIG. 13A , cables 60 a, 60 b, and 60 c are each positioned in one of the areas of widest extent between the restrictions. The vertical distance between each restriction may be four and five sixteenths inches (4 5/16″). An opening of slot 40 a may be fifteen sixteenths inches ( 15/16″). In this configuration, support post 30 a may be four inches (4″) wide, with a distance from the center of slot 40 a to an edge of post 30 a of two inches (2″).
[0069] FIG. 13B shows a slot 40 b suitable for use in a four-cable cable safety system 20 . Slot 40 b accommodates cables 60 a and 60 b. Two additional cables (such as, for example, cables 60 c and 60 d ) may be positioned on the outside of support post 30 b, as discussed above. In particular embodiments, slot 40 b may be open at a top end, positioned at the top of support post 30 b, and may have an overall length of eight and one-half inches (8½″). Slot 40 b may be one inch (1″) wide at its widest extent, and may include two restrictions formed along edges 41 b and 42 b that are each thirteen sixteenths inches ( 13/16″) wide. Cables 60 a and 60 b are each positioned in one of the areas of widest extent between the restrictions. The vertical distance between each restriction may be four and five sixteenths inches (4 5/16″). An opening of slot 40 b at the top of support post 30 b may be fifteen sixteenths inches ( 15/16″) wide. In this configuration, support post 30 b may be three inches (3″) wide, with a distance from the center of slot 40 b to an edge of support post 30 b of one and one-half inches (1½″).
[0070] As compared with slot 40 a, slot 40 b has narrower width between edges 41 b and 42 b in which cables 60 are positioned. This reduced distance between edges 41 b and 42 b allows for cables 60 and support post 30 b to interact more quickly in the manner described above with respect to FIG. 8 . Because cables 60 and support post 30 b are able to start working more quickly in slot 40 b (as compared to cables 60 in slot 40 a and post 30 a ), vehicles may be more effectively redirected away from away from hazardous areas by enabling cables 60 to provide resistance to vehicles impacting cable safety system 20 sooner after impact.
[0071] Moreover, because of the smaller overall dimensions of support post 30 b, support post 30 b may be manufactured at a reduced cost compared with previous designs. In particular, the inclusion of four cables 60 in cable safety system 20 allows for a shorter overall height of support post 30 b. A fourth cable 60 enables the top-most cable 60 to be positioned higher relative to ground level than previous systems. A higher overall cable height enables support post 30 b to be shorter overall. Additionally, the inclusion of four cables 60 may allow for the use of a thinner web in support post 30 b. Additionally, cable safety system 20 may be manufactured without punching holes in the bottom of support post 30 , which may substantially reduces the manufacturing cost of support post 30 b.
[0072] In combination with four cables 60 and other aspects of cable safety system 20 , the smaller and thinner size of support post 30 b is effective to improve redirection of vehicles away from hazardous areas without causing serious injuries to the vehicle's occupants or other motorists. A smaller post in combination with a three-cable design would not have performed as effectively because cable safety system 20 would have been less effective at preventing vehicles from submarining or passing through cable safety system 20 as compared to a four-cable design. A combination of a smaller and thinner support post 30 b may enable support post 30 b to be manufactured at a weight of 5.7 pounds per foot, compared with a weight of 7.7 pounds per foot for previous designs, thereby enabling substantial cost savings during manufacture and maintenance.
[0073] A typical installation process in accordance with particular embodiments of the present disclosure is now described. Posts 30 and anchors 24 and 26 are installed at desired location adjacent to a roadway and/or median. Cables are rolled out and spacers are placed, retaining the band and cap at each post. Cables are connected with appropriate fittings if the cables do not include prefabricated fittings. One end of each cable is connected with anchor 26 . Each cable is tensioned to a value of approximately 95% of the desired tension depending upon temperature and other environmental conditions. Each cable is marked, and an appropriate fitting is cut and attached. Each end of the respective cables is connected with the second anchor 26 . The tension in the is adjusted cables to a desired level. Spacers are installed within each post. A retaining band and cap is attached at each post.
[0074] Although embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and alternations can be made herein without departing from the spirit and scope of the invention as defined by the following claims. | A safety barrier comprising is disclosed. The safety barrier comprises a plurality of posts spaced from each other and disposed adjacent to a roadway, each post having a cross section defined in part by a web and a pair of legs extending therefrom. Additionally, each post has one slot formed in the web of the post extending from an upper end of the post. A first cable and a second cable are releasably engaged with and supported by the posts and disposed within each slot between the respective legs of each post. A third cable and a fourth cable are each coupled to an exterior surface of the posts. The posts and the first, second, third and fourth cables cooperate to prevent a vehicle from leaving the roadway. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates to masks for eyes and more particularly to opaque eye shields similar to spectacles or sunglasses but designed to facilitate sleeping under conditions (as in airplanes, trains, and cars, for example) where the wearer's environment may be illuminated.
BACKGROUND OF THE INVENTION
[0002] The disclosure of U.S. Pat. No. Des. 388,812 to Miehe, et al. appears exemplary of conventional styles of sleeping masks. Such masks typically include a fabric or cloth body to which one or more elastic bands are attached. In use, the body is positioned over the eyes of the wearer and generally held in place when the elastic bands are stretched about the wearer's head. Additionally, because the body is wholly flexible, it conforms, more or less, to the contours of the face of the wearer in the region it covers.
[0003] Omission of a relatively rigid nose- or ear-piece of the mask of the Miehe patent, however, can result in slippage of the body of the mask in use. This slippage in turn may decrease the comfort of the wearer, potentially waking him or her from restful sleep. These flexible masks further lack any stylishness, resembling neither aesthetically-attractive spectacles nor sunglasses.
[0004] U.S. Pat. No. 4,411,263 to Cook describes infant eye shields designed as alternatives to the traditional practice of taping gauze pads over infants' eyes during hospital procedures. As with other conventional masks, the eye shields of the Cook patent are made of flexible cloth (or film) and omit any rigid nose- or ear-piece. Instead, the shields are adhered to the temples of infants using adhesive of selected peel and shear strengths, with such adhesive being utilized to maintain the shields in position.
[0005] U.S. Pat. No. 4,908,878 to Tarragano, incorporated herein in its entirety by this reference, details yet another light shield, although for use primarily (but supposedly not exclusively) with hospitalized adults. It too “is made entirely of soft, non-woven fabric sheeting,” intentionally omitting any more rigid plastic or other material. Loops attached to the masking region of the shield engage the ears of a wearer to retain the shield in place. Although the Tarragano patent mentions (without explanation) “ultrasonically welding” the periphery of the shield and its loops, it nevertheless fails to suggest having any rigid masking region or nose- or ear-piece or structure resembling conventional spectacles or sunglasses.
SUMMARY OF THE INVENTION
[0006] The present invention, by contrast, provides more rigid masks or shields intended to block all (or substantially all) visible light from the eyes of the wearer. Such masks do not include elastic bands, adhesive, or loops to maintain them in position in use. Rather, relatively rigid nose- and ear-pieces are employed, in some respects similar to those of existing spectacles and sunglasses.
[0007] Additionally unlike conventional shields, the eye-covering regions of the innovative masks likewise are relatively rigid in comparison with cloths or fabrics. Thus, masks of the present invention may be made of one-piece construction, molded of plastic or other suitable material into a unitary body. If desired, frames of the masks may have some flexibility, much as many spectacle frames currently do, to permit at least some adjustment for enhanced conformance to features of the wearers' heads.
[0008] It thus is an object of the present invention to provide eye masks lacking any need for elastic bands, adhesive, and loops to permit their retention in position.
[0009] It is also an object of the present invention to provide eye masks whose frames and contours can be similar to those of attractive or stylish spectacles or sunglasses.
[0010] It is another object of the present invention to provide eye masks having opaque material in place of lenses so as to block some or all visible light from penetrating the masks to the wearers' eyes.
[0011] It is a further object of the present invention to provide eye masks having nose-pieces, ear-pieces, or both made of material other than flexible cloth or fabric.
[0012] It is an additional object of the present invention to provide eye masks which may be molded of plastic material and which may be of one-piece construction.
[0013] It is yet another object of the present invention to provide eye masks which facilitate sleeping in places, such as in cars, airplanes, and trains or outdoors, where ambient light may be present.
[0014] Other objects, features, and advantages of the present invention will be apparent to those skilled in the art with reference to the remaining text and drawings of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a front elevational view of portions of an eye mask of the present invention.
[0016] [0016]FIG. 2 is a perspective view of portions of the eye mask of FIG. 1.
[0017] [0017]FIG. 3 is another perspective view of portions of the eye mask of FIG. 1.
[0018] [0018]FIG. 4 is a side view of portions of the eye mask of FIG. 1.
[0019] [0019]FIG. 5 is a perspective view of an alternate eye mask of the present invention.
DETAILED DESCRIPTION
[0020] FIGS. 1 - 4 illustrate an exemplary eye mask 10 of the present invention. Mask 10 typically includes eye-covering regions 14 and 18 , associated respectively with the left and right eyes of a wearer. Also incorporated into mask 10 are ear-pieces 22 and 26 and nose-piece 30 , the latter of which comprises either or both of bridge 34 and pads 38 and 42 . Ear-piece 22 is adapted to contact the left ear of a wearer, while ear-piece 26 contacts the wearer's right ear. Nose-piece 30 , by contrast, contacts the wearer's nose in use, with bridge 34 also functioning to connect regions 14 and 18 .
[0021] Preferred embodiments of mask 10 are molded of plastic material having sufficient rigidity to maintain its overall shape absent application of manual or other pressure. Some embodiments of mask 10 presently contemplated will not change shape during any portion of normal use. Other embodiments, however, may permit a wearer to flex or bend (at least slightly) either or both of ear-pieces 22 and 26 and bridge 34 to adapt mask 10 better to the characteristics of the wearer's head. In either event, by making regions 14 and 18 , ear-pieces 22 and 26 , and nose-piece 30 of the same material, mask 10 can be of one-piece construction whether molded or otherwise formed.
[0022] At least regions 14 and 18 should be opaque for optimal results. Creating these regions 14 and 18 of black material of sufficient thickness to prevent all (or substantially all) visible light from reaching the wearer's eyes is preferred in connection with mask 10 , although those skilled in the art are aware that materials or colors other than black may be utilized instead. Thus, although some embodiments of mask 10 may be solid black in color, others may be or contain other colors (and indeed may be multi-colored if appropriate or desired).
[0023] If ear-pieces 22 and 26 are formed of substantially rigid material and mask 10 is of one-piece construction, ear-pieces 22 and 26 will not fold compactly like corresponding ear-pieces of conventional glasses. These versions of mask 10 are contemplated as being sufficiently inexpensive so as to be disposable after use rather than requiring storage. Of course, regardless of cost they need not necessarily be disposed of following use, and other embodiments of mask 10 may include hinges or other suitable mechanisms allowing ear-pieces 22 and 26 to fold more or less parallel to the general plane containing regions 14 and 18 .
[0024] As noted earlier, ear-pieces 22 and 26 are designed to contact the wearer's ears when mask 10 is being used. The ear-pieces 22 and 26 of FIGS. 2 - 4 likely will contact only the upper portions of the wearer's ears, in the uppermost areas of connection of the ears to the head. As shown particularly in FIG. 4, such ear-pieces 22 and 26 are relatively straight. Ear-pieces 22 and 26 need not be so formed, however, but instead may include terminal hooks (in essence, they may be shaped so as to resemble a rotated letter “J”) to engage additional portions of the wearer's ears.
[0025] Additionally as shown in FIGS. 2 and 4, each of ear-pieces 22 and 26 may include a portion 46 or 50 of increased width near the junction of pieces 22 and 26 with regions 14 and 18 . Increased-width portions 46 and 50 may be useful in inhibiting visible light from reaching the eyes peripherally and thus, if present, advantageously may be made of opaque material. Portions 46 and 50 need not have width greater than the remainder of ear-pieces 22 and 26 , however.
[0026] Together with ear-pieces 22 and 26 , nose-piece 30 helps maintain the position of mask 10 on a wearer's head. Typically either not bendable or only modestly so, bridge 34 of nose-piece 30 is adapted to contact and rest against the bridge of the wearer's nose. Pads 38 and 42 , in turn, contact and rest against opposed sides of the wearer's nose. If in the form shown in FIG. 3, pads 38 and 42 may comprise curved, increased-thickness areas of respective regions 14 and 18 . Pads 38 and 42 may be formed otherwise, however, if appropriate.
[0027] [0027]FIGS. 1, 2, and 4 collectively illustrate ridges 54 and 58 , which may demarcate respective central sections 62 and 66 of regions 14 and 18 from frame 70 . If, hypothetically, lenses were substituted for central sections 62 and 66 , ridges 54 and 58 effectively could indicate or overlap the edges of the lenses adjacent the frame of the glasses. Thus, in embodiments of mask 10 where ridges 54 and 58 (or either of them) are present, the ridges 54 and 58 can simulate (at least aesthetically) the presence of lenses and thereby enable the mask 10 more to resemble spectacles or sunglasses.
[0028] [0028]FIG. 5, by contrast, details an alternative mask 10 ′ lacking any ridges 54 or 58 or demarcations between central sections 62 and 66 and the remainder of frame 70 in regions 14 and 18 . Frame 70 thus may be smooth throughout regions 14 and 18 , unlike conventional spectacles and sunglasses. This characteristic of mask 10 ′ may simplify its being molded, for example, while additionally creating a sleeker, potentially more attractive appearance for the mask 10 ′.
[0029] The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Further modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention. | Eye masks having nose- and ear-pieces similar to those of conventional spectacles and sunglasses are described. Such masks include eye-covering regions of opaque material but need not include elastic bands, adhesive, or loops to retain the regions in place while in use. The masks additionally may be made of one-piece construction if desired, molded of plastic or other suitable material into a unitary body. | 0 |
[0001] The present application is a continuation of application Ser. No. 10/735,343, filed Dec. 11, 2003; which is a continuation of application Ser. No. 09/419,641, filed Oct. 18, 1999, now U.S. Pat. No. 6,662,471; which is a continuation of application Ser. No. 09/149,142, filed Sep. 8, 1998, now U.S. Pat. No. 5,970,628; which is a continuation of application Ser. No. 08/542,251, filed Oct. 12, 1995, now U.S. Pat. No. 5,806,210; all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to multi-purpose athletic shoes and, more particularly, to athletic shoes with interchangeable/detachable rear soles that provide extended and more versatile life and better performance in terms of cushioning and spring.
[0004] 2. Description of the Prior Art
[0005] Athletic shoes, such as those designed for running, tennis, basketball, cross-training, hiking, walking, and other forms of exercise, typically include a laminated sole attached to a soft and pliable upper. The sole usually includes an abrasion-resistant, rubber outsole attached to a cushioning midsole usually made of polyurethane, ethylene vinyl acetate (EVA), or a rubber compound.
[0006] One of the principal problems associated with athletic shoes is wear to both the outsole and midsole. A user rarely has a choice of running or playing surfaces, and asphalt and other abrasive surfaces take a tremendous toll on the outsole. This problem is exacerbated by the fact that, with the exception of the tennis shoe, the most pronounced outsole wear for most users, on running shoes in particular, occurs principally in two places: the outer periphery of the heel and the ball of the foot, with heel wear being, by far, a more acute problem because of the great force placed on the heel during the gait cycle. In fact, the heel typically wears out much faster than the rest of the athletic shoe, thus requiring replacement of the entire shoe even though the bulk of the shoe is still in satisfactory condition.
[0007] Midsole wear, on the other hand, results not from abrasive forces, but from repeated compression of the resilient material forming the midsole due to the large force exerted on it during use, thereby causing it to lose its cushioning effect. Midsole compression is also the worst in the heel area, particularly the outer periphery of the heel directly above the outsole wear spot and the area directly under the user's calcaneus or heel bone.
[0008] Despite higher prices and increased specialization, no one has yet addressed heel wear problems in an effective way. To date, there is nothing in the art to address the combined problems of midsole compression and outsole wear in athletic shoes, and these problems remain especially severe in the heel area of such shoes.
[0009] Designs are known that specify the replacement of the entire outsole of a shoe. Examples include those disclosed in U.S. Pat. Nos. 4,745,693, 4,377,042 and 4,267,650. These concepts are impractical for most applications, however, especially athletic shoes, for several reasons. First, tight adherence between the sole and the shoe is difficult to achieve, particularly around the periphery of the sole. Second, replacement of the entire sole is unnecessary based upon typical wear patterns in athletic shoes. Third, replacing an entire sole is or would be more expensive than replacing simply the worn elements, a factor which is compounded if a replaceable, full-length sole for every men's and women's shoe size is to be produced. Finally, it would appear that the heel section, in particular, has entirely different needs and requirements from the rest of the shoe sole which derive in substantial part from its rate of deterioration.
[0010] Other designs, which are principally directed to shoes having a relatively hard heel and outsole (e.g., dress shoes), disclose rear soles that are detachable and which can be rotated when a portion of the rear sole becomes worn. Such designs, however, have never caught on in the marketplace because it is simply too easy and relatively inexpensive to have the entire heel on such footwear replaced at a commercial shoe repair shop.
[0011] It is difficult to adapt such “dress shoe” designs to athletic shoes for various reasons. One reason is that the soft, resilient materials utilized in athletic shoe soles make it extremely difficult to devise a mechanism for detachably securing heel elements to each other without adversely affecting the cushioning and other desired properties of the shoe. On the other hand, utilization of hard materials in athletic shoes tends to increase weight and decrease comfort and performance.
[0012] For example, U.S. Pat. No. 1,439,758 to Redman discloses a detachable rear sole that is secured to a heel of the shoe with a center screw that penetrates the bottom of the rear sole and which is screwed into the bottom of the heel of the shoe. Such a design cannot be used in athletic shoes because the center screw would detrimentally affect the cushioning properties of the resilient midsole and may possibly be forced into the heel of the user when the midsole is compressed during use. Furthermore, a center screw does little for peripheral adherence of the sole to the shoe heel in the case of resilient materials.
[0013] Another truism in the athletic shoe industry is that, while cushioning has received a lot of attention, spring has received very little, despite the fact that materials like graphite and various forms of graphite composite possess the proper characteristics for spring enhancement without increasing weight. One reason may be the perceived tendency of graphite or graphite composite to crack under stress. Yet another reason may be the increased cost associated with such materials. Yet another reason may be that the tremendous variation in body weight and spring preference of would-be users makes it commercially unfeasible to mass-market athletic shoes with graphite spring enhancement, given the countless options that would have to be offered with each shoe size. Since heel spring is largely ignored, it goes without saying that spring options are also non-existent.
[0014] Also absent from the marketplace are truly multi-purpose athletic shoes. Notwithstanding a few “run-walk,” “aerobic-run,” and all-court models, the unmistakable commercial trend appears to be increased specialization, with no apparent industry awareness of the fact that the use and function of an athletic shoe can be changed dramatically if it is simply given interchangeable rear soles. Similarly, no athletic shoe manufacturer has yet to offer varying heel cushioning firmness in each shoe size, despite the fact that consumer body weight for each shoe size spans a huge spectrum. While a few manufacturers offer width options in shoe sizes, varying firmness of cushioning in a single model or shoe size is nonexistent in the marketplace.
SUMMARY OF THE INVENTION
[0015] The present invention is directed to a shoe that substantially obviates one or more of the needs or problems due to limitations and disadvantages of the related art.
[0016] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the system particularly pointed out in the written description and claims, as well as the appended drawings.
[0017] To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the shoe in one embodiment includes an upper having a heel region and rear sole support attached to the heel region of the upper. The rear sole support includes a base, a first wall extending downwardly from the base and having a first groove, and a second downwardly extending wall opposite the first wall and having a second groove facing the first groove. A rear sole is detachably secured to the rear sole support with a mounting member attached to the rear sole and including at least one rim for engaging the first and second grooves. A locking member engages the rear sole support and one of the rear sole and mounting member to prevent rotation of the rear sole relative to the rear sole support during use.
[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a Respective view of one embodiment of a shoe of the present invention.
[0021] FIG. 2 is an Exploded perspective view of the heel structure for the shoe own in FIG. 1 .
[0022] FIG. 3 is a perspective view of a rear sole support for the heel structure shown in FIG. 2 .
[0023] FIG. 4 is a perspective view showing the underside of the rear sole support shown in FIG. 3 .
[0024] FIG. 5 is a perspective view of another embodiment of the shoe of the present invention.
[0025] FIG. 6 is a perspective view of a rear sole support for the shoe shown in FIG. 5 .
[0026] FIG. 7 is a perspective view showing the underside of the rear sole support shown in FIG. 6 .
[0027] FIG. 8 is a side view of a rear sole for the heel structure shown in FIG. 2 .
[0028] FIG. 9 is a perspective view showing the underside of the rear sole show FIG. 8 .
[0029] FIGS. 10 A-C are bottom views showing alternative ground-engaging surfaces-for the rear sole shown in FIG. 8 .
[0030] FIG. 11 is a side view of a mounting member for the heel structure shown in FIG. 2 .
[0031] FIG. 12 is a perspective view of a locking member for the heel structure shown in FIG. 2 .
[0032] FIG. 13 is a perspective view showing the opposite side of the locking member shown in FIG. 12 .,
[0033] FIGS. 14 A-C are top, perspective, and side views, respectively, of a flexible plate for the heel structure shown in FIG. 2 .
[0034] FIGS. 15 A-C are top, perspective, and side views, respectively, of another embodiment of a flexible plate for use in the heel structure shown in FIG. 2 .
[0035] FIGS. 16A and 16B are top and side views, respectively, of another embodiment of the flexible plate for use in the heel structure shown in FIG. 2 .
[0036] FIG. 17 is an exploded perspective view of another embodiment of the heel structure of the present invention.
[0037] FIG. 18 is a perspective view of a mounting member for the heel structure shown in FIG. 17 .
[0038] FIGS. 19A and 19B are perspective views of a locking member for the heel structure shown in FIG. 17 .
[0039] FIG. 20 is an exploded perspective view of another embodiment of the heel structure of the present invention.
[0040] FIG. 21 is an exploded perspective view of another embodiment of the heel structure of the present invention.
[0041] FIG. 22 is a perspective view of several of the heel components shown in FIG. 21 .
[0042] FIGS. 23 A-C are top, side, and bottom views, respectively, of outsole segment for the heel structure shown in FIG. 21 .
[0043] FIG. 24 is an exploded perspective view of another embodiment of the heel structure of the present invention.
[0044] FIG. 25 is a perspective view of another embodiment of a rear sole for use with the shoe of the present invention.
[0045] FIG. 26 is an exploded perspective view of another embodiment of a heel structure of the present invention.
[0046] FIGS. 27A and 27B are side and front views, respectively, of a wafer for use in the heel structure shown in FIG. 26 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference characters will be used throughout the drawings to refer to the same or like parts.
[0048] FIG. 1 illustrates an embodiment of the shoe of the present invention. The shoe, designated generally as 20 , is an athletic shoe principally designed for running, walking, basketball, tennis, and other forms of exercise.
[0049] As shown in FIG. 1 , shoe 20 includes an upper 22 , which is that portion of the shoe that covers the upper portion of the user's foot. The upper may be made of leather, a synthetic material, or any combination of materials well known in the art.
[0050] A forward sole 24 is attached to the forefoot region of the upper. The forward sole is a lightweight structure that provides cushioning to the forefoot region, and may include an abrasion-resistant rubber outsole laminated to a softer, elastomeric midsole layer. The forward sole is attached to the upper in a conventional manner, typically by injection molding, stitching or gluing.
[0051] In some conventional shoes, the forward sole (simply referred to in the industry as a “sole”) would extend from the forefoot region to the rear edge of the heel. In other conventional models, portions of the outsole and/or midsole are reduced or eliminated in certain non-stress areas, such as the arch area, to reduce weight. However, in a radical departure from conventional shoes, the shoe in an embodiment of the present invention incorporates a heel structure, including a detachable rear sole, that significantly alleviates heel wear problems associated with conventional soles and provides enhanced cushioning and/or spring.
[0052] An embodiment of the heel structure is shown in FIGS. 1 and 2 and includes a rear sole support 26 attached to the heel region of the upper 22 , a rear sole 28 detachably secured to the rear sole support 26 , a mounting member 60 for detachably securing the rear sole 28 to the rear sole support 26 , and locking members 90 for preventing rotation of the rear sole 28 relative to the rear sole support 26 during use. In addition, the heel structure may include a flexible plate 80 for providing spring to the heel of the user and reducing wear caused by midsole compression.
[0053] As shown in FIGS. 3 and 4 , the rear sole support 26 includes a substantially oval or elliptically-shaped base 30 , with somewhat flattened, medial and lateral sides, having a top surface that is attached to the upper by stitching, gluing, or other conventional means. The shape of such base is not limited, and could be circular, polygonal, or any variation of the foregoing. A front wall 32 extends downwardly from a front edge of the base 30 , and a rear wall 38 extends downwardly from a rear edge of the base 30 . Together, the front and rear walls define a recess that, as later described, receives means for detachably securing the rear sole to the rear sole support.
[0054] The front wall 32 includes a lip 34 turned toward the recess, with lip 34 and the recess side of wall 32 defining an arc-shaped front groove. The rear wall 38 includes a lip 40 turned toward the recess, with lip 40 and the recess side of wall 38 defining an arc-shaped rear groove otherwise substantially identical to and facing the front groove. The front and rear grooves have the same radius of curvature and together may constitute arcs of a common circle. At least one, and preferably both, of the front and rear grooves disclosed in FIG. 4 (and all drawings that disclose front and rear grooves), define a circular arc that is less than 180°. As shown in all of such drawings, both of such circular arcs also may substantially traverse the rear sole support 26 from its lateral to its medial side. The front and rear grooves may also be shaped to define arcs of a common circle having a diameter greater than the width of the rear sole support 26 or mounting member 60 or rear sole 28 or even the heel region of the upper 22 . The front and rear walls may be flush with the outer edge of base 30 and are spaced from each other on the medial and lateral sides of the base by a distance X, as shown in FIG. 4 , which may be slightly greater than the width of the rear sole support 26 or mounting member 60 or rear sole 28 .
[0055] The rear sole support also has a central opening 36 directly below the heel region of the upper. This central opening, which may be circular, oval, or virtually any polygonal shape, allows the heel of the user to be cushioned by the rear sole attached to the rear sole support or by the flexible plate 80 , instead of the firm material comprising the rear sole support.
[0056] The rear sole support may be composed of hard plastic, such as a durable plastic manufactured under the name PEBAX.™, graphite, a graphite composite, or other material having sufficient rigidity and strength to securely engage the rear solve attaching mechanism (discussed below). Injection molding or other conventional techniques may be used to form the rear sole support.
[0057] The rear sole support 26 may also include a heel counter 44 , as shown in FIG. 3 , for providing lateral stabilization to the user's heel. The heel counter extends upwardly from the edge of the base 30 in a contoured fashion and is preferably made of the same material as, and integral with, the rear sole support through injection molding or other conventional techniques.
[0058] As shown in FIGS. 1-4 , an arch bridge 46 may generally extend from the base 30 of the rear sole support to the forward sole for supporting the arch region of the foot. The arch bridge 46 is an optional feature composed of a firm, lightweight material. The arch bridge 46 is attached to the upper 22 and forward sole 24 by gluing or other conventional methods. The arch bridge 46 also may be composed of the same material as the rear sole support or a more flexible material and may be made integral with the rear sole support. Such one-piece construction of the arch bridge together with the rear sole support solves a major problem, and that is the tendency of an athletic shoe of conventional “full body” arch construction to curl or twist at the juncture of the hard rear sole support and the resilient forward sole. It also reduces the weight of the shoe by reducing or eliminating the midsole material, e.g., polyurethane or EVA, that would normally occupy the arch area of the shoe.
[0059] The rear sole support, heel counter, and arch bridge need not be made of a solid material. Holes or spaces may be created, at the time of manufacture, throughout the structure to decrease weight without diminishing strength.
[0060] As an alternative to the arch bridge 46 , the rear sole support 26 in all of the embodiments may include upper and lower horizontal walls 144 and 145 , as shown in FIGS. 5-7 , extending from, and preferably integrated with, front wall 32 . In this embodiment, the forward sole 24 extends into the arch region and is sandwiched between upper and lower walls 144 and 145 and against front wall 32 . It may then be further secured by gluing. As a further alternative, the rear portion of the forward sole may simply extend to the rear sole support, without upper and lower walls 144 and 145 , and be glued to the front wall 32 . Alternatively, the rear sole support 26 could have one wall like either 144 or 145 extending from and preferably integrated with it, but not both walls; or posts, rods, or other members, substantially parallel to the ground, could be substituted for walls and may extend from and be integrated with front Wall 32 into or along the surface of the midsole or outsole material in the forward sole and then secured by gluing. Other means may be employed as an alternative to the arch bridge 46 . An advantage to combining the rear sole support with walls 144 and/or 145 , or eliminating both of such walls entirely, and all other alternatives to the integral arch bridge, is that such options, unlike the integral arch bridge, permit manufacture of only one rear sole support suitable for either the left or right shoe, thus decreasing manufacturing costs.
[0061] The heel structure shown in FIG. 2 also includes a rear sole 28 detachably secured to the rear sole support. As shown in FIGS. 8 and 9 , rear sole 28 may include a ground-engaging outsole 48 laminated to a midsole 50 , which may be more resilient than the outsole, with both the outsole and midsole being more resilient than the rear sole support. The outsole, which may be composed of a rubber compound, provides abrasion resistance and some cushioning, while the midsole, which may be composed of a more resilient, elastomeric material such as polyurethane, ethylene vinyl acetate (EVA), HYTREL.™ (made by E.I. DuPont de Nemours & Co.), or other materials well known in the art, primarily provides cushioning to the heel during heel strike. Optionally, the rear sole could be comprised of a single homogenous material, or any number of layers or combinations of materials, including a material comprising air encapsulating tubes disclosed, for example, in U.S. Pat. No. 5,005,300.
[0062] The outsole 48 may be planar or non-planar. Preferably, the outsole, particularly on running shoe models, includes one or more tapered or beveled segments 52 , as shown in FIG. 8 , which when located at the rear of the shoe will soften and/or align heel strike during the gait cycle. The beveled segments 52 may be located at the front and rear portions of the rear sole, as shown in FIG. 10A , slightly offset from the front and rear portions, as shown in FIGS. 10B and 10C , or at any other location, depending on the preference of the user or any heel strike or wear pattern. The beveled segments 52 may also be aligned on a “special order” basis to deal with particular pronation or supination characteristics of the user.
[0063] As shown in FIG. 9 , rear sole 28 is elliptical or oval in shape, with somewhat flattened medial and lateral sides, with its length along the major axis of the shoe (when attached to the rear sole support and ready for use) being greater than its lateral width. As a result, the rear sole has a greater ground-engaging surface than if it were circular or equilaterally polygonal. Such increased ground-engaging surface provides greater stability, particularly if multiple or large beveled segments are used. However, the shape of the rear sole 28 may also be circular, polygonal, or otherwise. Regardless of the shape of the rear sole 28 , outsole 48 has an aggregate area having a substantially planar surface and multiple beveled surfaces non-planar with the planar surface. An aggregate area of the beveled surfaces is less than the remaining aggregate area of outsole 48 , as shown in FIGS. 2, 5 , 8 , 9 , 10 A-C, 17 , 20 , and 26 , to provide a stable ground-engaging surface for the wearer of the shoe. Rear sole 28 may or may not feature a hole in its center as shown in FIG. 9 , and preferably should not exist if flexible plate 80 (later discussed) is not used.
[0064] Rear sole 28 is detachably secured to the rear sole support 26 with a mounting member 60 . As shown in FIGS. 2 and 11 , mounting member 60 has a base layer 62 that is affixed to the top surface of the rear sole 28 with adhesive or other conventional means that will not degrade the cushioning/spring properties of the rear sole. There is an engaging layer 64 above base layer 62 and notch layer 74 A. Lateral sides 66 each contain protrusions 68 with bulbous ends. Front and rear ends 70 of the engaging layer 64 include circular arc-shaped rims 72 having substantially the same radius of curvature as the front and rear grooves of the rear sole support and engage the front and rear grooves of the rear sole support.
[0065] For the embodiments of the present invention relating to detachable rear soles, to attach the rear sole to the rear sole support, the rear sole, with the mounting member 60 attached (and, optionally, with a flexible plate 80 , discussed later, supported on the mounting member 60 ), is positioned relative to the rear sole support so that the front and rear rims of the mounting member are rotated in a circular manner no more than about 90°, about axis Y from their positions shown in FIG. 2 . The mounting member is centered between the front and rear grooves, then pressed against the bottom of the base 30 and rotated less than 180°, and generally no more than about 90° (clockwise or counterclockwise), so that rims 72 fully engage the front and rear grooves of the rear sole support defined by lips 34 and 40 seen in FIG. 4 . When the rear portion of the rear sole becomes worn, the rear sole can be rotated in a circular manner 180° so that the worn rear portion now faces toward the front of the shoe and occupies an area somewhat forward of the calcaneus where little or no weight of the user is applied. When the rotated rear portion of the rear sole also becomes worn, the rear sole may be detached and exchanged with the rear sole of the other shoe, since wear patterns of left and right heels are typically opposite. The rear sole may also be discarded and replaced with a new one with or without any rotation or exchange between left and right shoe.
[0066] The mounting member 60 may be made of any number of hard, lightweight materials that provide sufficient strength and rigidity to firmly engage the rear sole support, and support the flexible plate 80 if used. Examples of such materials include: hard plastic; PEBAX.™; HYTREL.™ in its hard format; graphite; and graphite, graphite/fiberglass, and fiberglass composites. Hardness of the mounting member may in fact be especially important if flexible plate 80 is used, because the peripheral edges of such plate need to press against a firm foundation if the central portion of such plate is to properly deflect under the weight of the user's foot and impart spring to the user's gait cycle. In any event, the mounting plate material is generally stiffer than the materials used for the rear sole midsole and outsole.
[0067] Base layer 62 may be entirely eliminated from the mounting member 60 shown in FIG. 2 , in which case the periphery of the top surface of rear sole 28 presses tightly against lips 34 and 40 of the rear sole support when engaged.
[0068] To prevent the rear sole from rotating relative to the rear sole support once engaged with each other, locking members 90 lock the mounting member to the rear sole support at the appropriate orientation. As shown in FIGS. 12 and 13 , locking member 90 includes a base 92 with a substantially planar inner surface 94 and an outer surface 96 contoured according to the sides of the rear sole support when attached thereto. A pair of L-shaped arms 98 extend from the base 92 (preferably from its top, e.g., from the external surface of the heel counter) and engage opposed openings 42 ( FIG. 2 ) in the rear sole support to pivotally attach the locking member 90 to the rear sole support. Openings 42 may also be formed in the heel region of the upper. When attached to the rear sole support, the locking members occupy the spaces (having a length X as shown in FIG. 4 ) between the front and rear walls of the rear sole support, as shown in FIG. 1 .
[0069] Apertures 100 are formed in the base 92 for receiving the protrusions 68 of mounting member 60 . The apertures have a small opening adjacent surface 94 , then expand in diameter within the base to a larger opening near surface 96 to accommodate the bulbous ends of the protrusions 68 . As a result, the protrusions “snap” into the apertures 100 to lock the locking members in position. In addition, projections 102 extend inwardly from opposite ends of base 92 and engage notches 74 in the mounting member between the front and rear ends and the lateral sides ( FIGS. 2 and 11 ) to prevent rotation of the rear sole when the locking members are in the position shown in FIG. 1 .
[0070] For the embodiment of the present invention relating to flexible plates, and as shown in FIG. 2 , mounting member 60 includes slots 76 for supporting a flexible plate 80 between the rear sole and the heel portion of the upper so that a portion of plate 80 is exposed through central opening 36 . The flexible plate, which may be made of a graphite composite or other stiff, but flexible, material, reduces heel-center midsole compression and provides spring to the user. The flexible plate is, of course, stiffer than the materials used for the outsole or midsole, but must be sufficiently flexible so as to not detrimentally affect cushioning of the user's heel. A graphite or graphite/fiberglass composite, including carbon or carbon and graphite fibers woven in an acrylic or resin base, such as those manufactured by Biomechanical Composites Co. of Camarillo, Calif., may be used.
[0071] As shown in FIGS. 14 A-C, flexible plate 80 includes front and rear edges 82 and 84 that are supported by slots 76 (see FIG. 2 ) in the mounting member. The flexible plate may have a substantially convex upper surface that curves upwardly between the front and rear edges to an apex 86 , which is preferably located below the calcaneus of the user when the rear sole is attached to the rear sole support. An aperture 88 may be provided at the apex 86 to increase spring.
[0072] The plate may also be flat or concave, and may be substantially hour glass-shaped, as shown in FIGS. 14 A-C, or H-shaped, as is the plate 180 shown in FIGS. 15 A-C. Other shapes are also contemplated as long as such shapes provide spring and reduce midsole compression of the rear sole. For example, FIGS. 16A and B show another hour glass-shaped flexible plate 280 with discrete upper and lower sections 282 and 284 .
[0073] When the flexible plate is used, the rear sole may be devoid of material in its center, as shown in FIG. 2 , to reduce the weight of the rear sole. If the center is devoid of material, a thin horizontal membrane (not shown), with or without a flanged edge, composed of plastic or other suitable material may be inserted into the void and attached to the walls of the void, by compression fit or otherwise, to seal the void and prevent moisture or debris from entering or collecting therein.
[0074] Apex 86 is located, in FIGS. 14C and 15C , slightly to the rear of the center of the major axis of plate 80 , so as to be positioned more directly beneath the center of the calcaneus. Thus, it will be necessary to remove and rotate plate 80 by 180° on an axis perpendicular to the major axis of the shoe when the rear sole is rotated, in order to keep the apex positioned directly beneath the calcaneus. However, plate 80 may be formed with the apex in any position to suit a user's preference. It may even be placed in the exact center of plate 80 so as to obviate the need for plate rotation when the rear sole is rotated.
[0075] Flexible plate 80 provides spring to the user's gait cycle in the following manner. During heel strike in the gait cycle, the user's heel provides a downward force against the plate. Since the peripheral edges of the plate are firmly supported by the mounting member, the interior portion of the plate deflects downwardly relative to the peripheral edges. As the force is lessened (with the user's weight being transferred to the other foot) the deflected portion of the plate, due to its elastic characteristics, will return to its original shape, thereby providing an upward spring force to the user's heel. Such spring effect will also occur whenever a force is otherwise applied to and then removed from the flexible plate (e.g., jumping off one foot, or jumping from both feet simultaneously).
[0076] The removability of the flexible plate allows the use of several different types of flexible plates of varying stiffness or composition. Thus, flexible plate designs and characteristics can be adapted according to the weight of the user, the ability of the user, the type of exercise or use involved, or the amount of spring desired in the heel of the shoe. Removability also permits easy replacement of the plate should deterioration occur, a concern in the case of virtually any truly spring-enhancing plate material.
[0077] The heel structure embodiment shown in FIG. 2 is but one of many embodiments contemplated by the present invention. While further embodiments are discussed below, additional embodiments are possible and within the scope of the invention. Unless otherwise noted, the structure, material composition, and characteristics of the heel components shown in FIGS. 1 and 2 apply to all of the embodiments.
[0078] One such embodiment is shown in FIGS. 17-19B . In this embodiment, rear sole support 126 is substantially identical to rear sole support 26 shown in FIG. 2 except that it has horizontal grooves 128 on the exterior surfaces of each of the downwardly extending walls and no holes 42 . The mounting member 160 shown in FIG. 17 is also identical to mounting member 60 shown in FIG. 2 except that protrusions 168 do not have bulbous ends.
[0079] Locking members 190 differ from those shown in FIG. 2 in that the hinges are eliminated. Instead, the exterior surfaces of each of the locking members 190 have a horizontal groove 192 that aligns with the exterior grooves 128 formed on the rear sole support. In addition, apertures 194 ( FIG. 19A ) are cylindrical in shape and need not have expanded interior portions since the protrusions 168 have no bulbous ends.
[0080] To lock the locking members in place, an elastic band 110 is stretched and fitted within the grooves 128 on the rear sole support and grooves 192 on the locking members. The elastic band 110 may be a separate component completely removable from the rear sole support, as shown in FIG. 17 , or permanently secured to the rear sole support by, for example, enclosing one of the grooves 128 after the elastic band has been inserted therein. Also, the band may be pushed or rolled upward above grooves 128 on the rear sole support prior to detaching locking members 190 , and then simply rolled downward to return to an in-groove position following reattachment. As a further option, the elastic band may be a removable or permanently attached strap fitted within the grooves and having opposing ends that may be latched together like a belt or ski boot latch.
[0081] As a further alternative (not shown), a U-shaped connector having opposite ends permanently attached to one end of both locking members 90 may be removably or permanently secured to the outer surface of either the front or rear wall of the rear sole support, as a substitute for the system involving hinges 98 on locking members 90 . The elastic band and other alternatives to the hinged locking member can be used in all of the embodiments of the invention.
[0082] If a flexible plate is not desired, the embodiment shown in FIG. 20 may be used to supply tore conventional midsole cushioning. In this embodiment, the mounting member 260 is identical to the mounting member 60 shown in FIG. 2 except that the base layer and slots 76 are eliminated. It should again be noted that the base layer 62 is an optional feature in all of the mounting member embodiments. In place of the rear sole 28 shown in FIG. 2 , a rear sole 200 has an abrasion-resistant outsole 202 laminated to a midsole layer 204 . On top of this midsole layer 204 are two additional midsole layers 206 and 208 , each layer being smaller than the layer upon which it rests, with midsole layer 208 sized to fit within the central opening 36 in the rear sole support 26 . Midsole layers 206 and 208 may comprise two separate pieces laminated together or a single piece molded or otherwise shaped to have two regions as shown.
[0083] In this embodiment, the mounting member 260 is adhered by gluing or other means to the top of the midsole layer 204 such that it surrounds and abuts against the sides of midsole layer 206 . It may be further secured to the sides of midsole layer 206 by gluing or other means. The manner of attaching the rear sole and mounting member to the rear sole support is identical to that describe with respect to the embodiment shown in FIG. 2 . In addition, the top midsole layer 208 may, but need not be, made circular to facilitate rotation of the rear sole when the midsole layer 208 is pressed into the central opening 36 . Alternatively, this layer may be severed from layer 206 and placed in opening 36 with the shoe in an inverted position. This may make installation easier if layer 208 is oval in shape, like opening 36 . It also permits replacement of layer 208 , should its cushioning properties deteriorate at a faster rate than the rest of the rear sole. Of course, this step would be accomplished before engagement of mounting member 260 with rear sole support 26 , which similarly could be accomplished while the shoe is in an inverted position in order that layer 208 does not fall out or dislodge during installation.
[0084] It should be noted that layers 204 , 206 , and 208 may be made of different cushioning materials, including without limitation air-filled chambers, gell-filled chambers, EVA or polyurethane, or any combinations thereof.
[0085] The rear sole support is designed to accommodate a variety of rear sole configurations, which vary according to the activity involved, the weight of the user, and the cushioning and/or spring desired by the user. Although additional rear sole configurations are discussed below, many other rear sole configurations may be used in conjunction with the rear sole support 26 .
[0086] One such example is shown in FIGS. 21 and 22 . In this embodiment, a rear sole 300 is a U-shaped member having substantially parallel walls 302 and 304 joined by a bend 305 . The member is composed of a stiff, but flexible, material that will provide spring to the heel of the user without sacrificing comfort. Materials such as those disclosed with respect to the flexible plate 80 may be used for the rear sole 300 .
[0087] Two layers of resilient midsole material 206 and 208 , which may be more resilient than the U-shaped member, are secured to the top of wall 302 by gluing or other means to provide cushioning to the heel of the user, and mounting member 260 is glued or otherwise attached to the top surface of top wall 302 to surround and abut against the sidewall of midsole layer 206 . It may also be attached to the side wall of layer 206 by gluing or other means. The mounting member may also be molded to the rear sole 300 as a one-piece structure. The midsole layers 206 and 208 , the mounting member 260 , and the rear sole support 26 (as well as optional features) are identical to those shown in FIG. 20 , and the manner and options for attaching the rear sole and mounting member to the rear sole support is the same, including without limitation the option of severing and separately installing layer 208 .
[0088] To protect the bottom ground-engaging surface of the U-shaped member and to provide cushioning, the rear sole may include an abrasion-resistant outsole which may be more resilient than the U-shaped member. As shown in FIG. 21 , the bottom wall 304 of the rear sole 300 includes holes 306 through which removable outsole segments 308 are inserted. The outsole segments 308 , which may be made of a rubber compound or other material typically used for outsole material, provide an abrasion-resistant layer for protecting the bottom surface of wall 304 . As shown in FIGS. 23 A-C, the outsole segments have a substantially conically-shaped top portion 316 , a cylindrical middle portion 318 , and a rounded ground-engaging portion 320 . The conically-shaped portion 316 snaps into openings 306 , and the bottom of the conically-shaped portion acts to retain the outsole segments in the openings. Alternatively, a one-piece outsole layer may be attached to the bottom surface of wall 304 , utilizing openings 306 and segments 308 , or eliminating both and utilizing gluing or some other means instead. Such outsole layer may then be permanent or removable.
[0089] The rear sole 300 provides spring to the heel of the user in the following manner. When the heel of the user strikes the ground, wall 304 will deflect toward wall 302 . Since the material is elastic, energy stored in bend 305 and wall 304 during deflection will spring bend 305 and wall 304 back to their original position as weight is shifted, thereby providing a spring effect to the user's heel. Stiffening members 312 or 312 A are optional elements that may be used to increase the spring generated by the rear sole 300 . The stiffening members include protrusions 314 that engage apertures 310 in the bend of the rear sole 300 . Alternatively, bottom wall 304 (shown with large hole in middle) may be solid to increase spring or may be tent-shaped as shown in FIG. 25 to further increase spring, with or without a stiffening member 412 .
[0090] Flexible plate 80 may also be used in conjunction with a rear sole very similar to that shown in FIG. 21 . As shown in FIG. 24 , rear sole 400 is identical to rear sole 300 shown in FIG. 21 except that it has an optional opening in the top wall to reduce the weight of the rear sole and allow additional space within which flexible plate 80 may flex. Alternatively, the bottom wall may be solid to increase spring or may be tent-shaped as shown in FIG. 25 to further increase spring, with or without a stiffening member 412 . Mounting member 360 is similar to that shown in FIG. 2 except that the base 62 is deleted. Again, flexible plate 80 rests in slots 376 formed in the mounting member and is exposed to the heel region of the upper via the central opening 36 in the rear sole support 26 .
[0091] Another rear sole option is shown in FIG. 25 . In this embodiment, rear sole 500 is identical to rear sole 400 shown in FIG. 24 except that it has a “tent-like” wall 506 extending from the bottom wall 504 toward top wall 502 . Wall 506 may have a top surface 508 , or may be devoid of material at this location. Wall 506 has the effect of increasing stiffness and, therefore, provides more spring than that of the rear sole 400 as shown. A stiffening member 412 may also be used to further increase spring. Stiffening member 412 is identical to member 312 shown in FIGS. 24 except that it has a slanted wall 413 to complement and press against the front sloped surface of wall 506 . Top wall 502 may have a central opening, as shown in FIG. 25 , or may be solid, such as wall 302 shown in FIG. 21 . Wall 506 may be used in any of the U-shaped rear sole embodiments.
[0092] Finally, an optional wafer 600 , usable in combination with any of the above embodiments incorporating a flexible plate, is disclosed in FIGS. 26-27B . As shown in FIG. 26 , wafer 600 is disclosed in conjunction with the heel structure shown in FIG. 2 . Wafer 600 is placed on the top surface of flexible plate 380 so that it is exposed to the heel region of the upper (not shown) via central opening 36 of rear sole support 26 . Wafer 600 is made of any suitable materials, such as those materials disclosed for the midsole layer or outsole layer of rear sole 28 , that provide cushioning to the heel of the user and which are more resilient than the flexible plate.
[0093] As shown in FIGS. 27A and 27B , wafer 600 includes knobs 602 and 604 that snap engage with corresponding openings 382 and 384 (see FIG. 26 ) in flexible plate 380 . Although two knobs are shown in this embodiment, any number of knobs may be used; in fact, the knobs may be eliminated entirely.
[0094] As shown in FIG. 26 , wafer 600 is oval in shape, although any shape is contemplated so long as it provides the desired cushioning to the heel of the user. If desired, the bottom surface 0 . 608 of wafer 600 may be concave in order to conform with the curved top surface of flexible plate 380 . The top surface 606 of wafer 600 may also be concave in order to conform with the contours of the heel region of the upper or the user's heel.
[0095] The wafer need not be attached to the flexible plate 380 . Instead, the wafer may, for example, be permanently attached to the bottom of the upper, secured within or made integral with a shoe sock liner (not shown), secured to the rear sole support, or attached at any other location that would be capable of cushioning the user's heel.
[0096] It will be apparent to those skilled in the art that various modifications and variations can be made in the shoe of the present invention without departing from the scope or spirit of the invention and that certain features of one embodiment may be used interchangeably in other embodiments. By way of example only, the rear sole support/locking member combinations shown in FIGS. 2 and 17 can be used in conjunction with any of the above-described rear sole configurations, and can be used with or without the flexible plate. Similarly, the arch bridge shown in FIGS. 1-4 , upper and lower horizontal walls shown in FIGS. 5-7 and other alternatives to the arch bridge discussed herein may be employed with any embodiment shown. Thus, it is intended that the present invention cover all possible combinations of the features shown in the different embodiments, as well as modifications and variations of this invention, provided they come within the scope of the claims and their equivalents. | A heel support for an athletic shoe that in one embodiment includes a recumbent-U shaped member to assist in shock absorption. The member may include a tent-shaped wall with an upper perimeter in contact with a non-ground-engaging member. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to wind power generation, and more particularly to a shaft brake mechanism of wind power generator.
In wind power generation, as the wind blows, the blades are driven to make the shaft of the generator rotate for converting kinetic energy into electrical energy. However, it is necessary to brake the shaft against rotation in some situations. Conventionally, an electromagnetic brake system is generally used to provide braking effect for the shaft. Such electromagnetic brake system must be continuously powered to keep providing braking effect or stop providing braking effect, allowing the shaft to rotate. As a result, a large amount of electrical energy is consumed for maintaining the function of such electromagnetic brake system.
Moreover, as shown in FIG. 10A , when a wind power generator operates in a condition that the rotational speed exceeds a nominal upper limit t 1 , the safety in operation will be threatened. Therefore, in the case that the wind speed exceeds a nominal upper limit t 2 of wind speed and the rotational speed of the shaft reaches the nominal upper limit t 1 , it is necessary to stop the system. In this case, the total power generation capacity of the wind power generator will be reduced and the natural wind power resource can be hardly fully utilized to cause waste of resource.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a shaft brake mechanism of wind power generator, in which the electrical power for providing braking effect for the shaft is much less than that of the conventional device. Therefore, the shaft brake mechanism of the present invention has energy-saving effect.
It is a further object of the present invention to provide the above shaft brake mechanism of wind power generator, in which a smaller force is input to create a greater output force for providing braking effect for the shaft. Therefore, the shaft brake mechanism of the present invention has power-saving effect.
It is still a further object of the present invention to provide the above shaft brake mechanism of wind power generator, which can naturally restrain the rotational speed of the shaft from proportionally increasing with the wind speed. Therefore, the wind power generator can still safely operate in a condition that the wind speed exceeds a nominal upper limit of wind speed. Accordingly, without modifying the nominal upper limit of rotational speed, the nominal upper limit of wind speed can increase to increase total power generation capacity.
To achieve the above and other objects, with respect to the energy-saving effect and power-saving effect, the shaft brake mechanism of wind power generator of the present invention includes: a shaft; an annular disc coaxially fixedly fitted around the shaft and synchronously rotatable with the shaft; a clamping section having two first fulcrums and two elongated rock arms each having a first end, a middle section and a second end, the middle sections of the rock arms being respectively pivotally connected with the first fulcrums, the clamping section further having two clamping members respectively pivotally connected with the first ends of the rock arms and rotatable between a clamping position and a releasing position, when positioned in the clamping position, the clamping members tightly abutting against two faces of the disc to brake the disc against rotation, when positioned in the releasing position, the clamping members moving away from the two faces of the disc, a resilient member being bridged between the second ends of the rock arms for resiliently keeping the clamping members in the releasing position; a link section having a second fulcrum and a bar member having a first end, a middle section and a second end, the first end of the bar member being pivotally connected with the second fulcrum, whereby the bar member is rotatable about the second fulcrum between a first position and a second position, the link section further having a push block with a substantially trapezoidal cross section, the push block having two lateral slopes respectively adjacent to the second ends of the rock arms, a middle section of the push block being pivotally connected with the middle section of the bar member, when the bar member is moved to the first position, the push block being urged to move toward the first ends of the rock arms and interpose between the second ends thereof, whereby the two lateral slopes push the second ends of the rock arms away from each other to make the clamping members move to the clamping position, when the bar member is moved to the second position, the push block being moved from between the second ends of the rock arms, whereby the resilient member applies a resilient force to the rock arms to restore the clamping members to the releasing position; and a drive section for supplying power to drive and reciprocally move the bar member between the first position and the second position.
With respect to the increase of the nominal upper limit of wind speed without modification of the nominal upper limit of rotational speed, the shaft brake mechanism of wind power generator of the present invention includes: a shaft; a pier having a seat body, a shaft hole being formed through the seat body, the shaft being coaxially rotatably fitted through the shaft hole; a hoof section having an annular base coaxially fitted around and fixedly connected with the shaft, the hoof section further having at least two hoofs each having a pivot shaft, the hoofs being respectively pivotally mounted on the base via the pivot shafts and positioned around the shaft at equal angular intervals, the hoofs being arranged in a pattern centered at an axis of the shaft with the pivot shafts parallel to the axis of the shaft, whereby the hoofs can be pivotally rotated about the pivot shafts between a braking position and a releasing position, at least one resilient member being bridged between the hoofs for resiliently restoring the hoofs from the braking position to the releasing position; and a ring-shaped drum fixedly mounted on the seat body of the pier, the shaft coaxially passing through the drum with the hoofs facing an inner circumference of the drum, the hoofs being synchronously rotated with the shaft, when a centrifugal force applied to the hoofs overcomes resilient force of the resilient member, the hoofs moving from the releasing position to the braking position where the hoofs abut against the inner circumference of the drum, whereby under frictional force between the hoofs and the drum, the shaft is restrained against rotation to prevent rotational speed of the shaft from unlimitedly increasing.
The present invention can be best understood through the following description and accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective assembled view of a preferred embodiment of the present invention;
FIG. 2 is a perspective exploded view of the first brake assembly of the preferred embodiment of the present invention;
FIG. 3 is a perspective assembled view of the first brake assembly of the preferred embodiment of the present invention;
FIG. 4 is a plane view of the preferred embodiment of the present invention, showing that the first brake assembly releases the shaft;
FIG. 5 is a plane view of the preferred embodiment of the present invention according to FIG. 4 , showing that the first brake assembly is actuated to brake the shaft;
FIG. 6 is a perspective exploded view of the second brake assembly of the preferred embodiment of the present invention;
FIG. 7 is a perspective assembled view of the second brake assembly of the preferred embodiment of the present invention;
FIG. 8 is a sectional view taken along line a-a of FIG. 7 , showing that the second brake assembly releases the shaft;
FIG. 9 is a sectional view according to FIG. 8 , showing that the second brake assembly naturally brakes the shaft when the rotational speed of the shaft increases;
FIG. 10A is a curve diagram showing that when the wind speed reaches the nominal upper limit t 2 , the shaft is braked and stopped; and
FIG. 10B is a curve diagram showing that without modifying the nominal upper limit of rotational speed of the shaft, the nominal upper limit of operational wind speed increases from t 2 to t 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Please refer to FIGS. 1 to 9 . According to a preferred embodiment, the shaft brake mechanism 10 of wind power generator of the present invention includes a board-like bed 20 , a first pier 30 , a second pier 40 , a shaft 50 , a first brake assembly 60 and a second brake assembly 70 .
The piers 30 , 40 are side by side disposed on the bed 20 . Each of the piers 30 , 40 has an upright plate-like seat body 31 , 41 in which a bearing is inlaid. The bearings of the piers 30 , 40 have central shaft holes, which are coaxially aligned with each other.
The shaft 50 is rotatably fitted through the shaft holes of the bearings and bridged between the piers 30 , 40 .
The first brake assembly 60 provides braking effect for the shaft 50 by means of disc brake technique. The first brake assembly 60 includes an annular disc 61 coaxially fixedly fitted around the shaft 50 between the piers 30 , 40 . The disc 61 is rotatable with the shaft 50 . The first brake assembly 60 further includes a clamping section 62 for tightly clamping the disc 61 to provide braking effect. The first brake assembly 60 further includes a link section 63 drivable by a drive section 64 for controlling the clamping section 62 to or not to provide braking effect for the shaft 50 .
To speak more specifically, the clamping section 62 has a U-shaped support 621 having a horizontal section and two upright sections. The horizontal section of the U-shaped support 621 is fixedly disposed on the bed 20 . Each of the upright sections has a free end serving as a first fulcrum 622 . The clamping section 62 further has two elongated rock arms 623 each having a first end, a middle section and a second end. The middle sections of the rock arms 623 are respectively pivotally connected with the first fulcrums 622 . Two clamping members 624 are respectively pivotally connected with the first ends of the rock arms 623 and rotatable between a clamping position and a releasing position. A resilient member 625 is bridged between the second ends of the rock arms 623 for resiliently keeping the clamping members 624 in the releasing position. To speak more specifically, each clamping member 624 has a clamping plate 6241 . Two linings 6242 are respectively attached to the opposite faces of the clamping plates 6241 . Two pivot blocks 6243 are respectively fixed on the other faces of the clamping plates 6241 . The pivot blocks 6243 are pivotally connected with the first ends of the rock arms 623 via pivot shafts.
The link section 63 has a rod-like second fulcrum 631 fixedly disposed on the bed 20 . The link section 63 further has a bar member 632 having a first end, a middle section and a second end. The first end of the bar member 632 is perpendicularly pivotally connected with the second fulcrum 631 , whereby the bar member 632 is rotatable about the second fulcrum 631 between a first position and a second position. The link section 63 further has a board-shaped push block 633 with a trapezoidal cross section. A middle section of the push block 633 is pivotally connected with the middle section of the bar member 632 . Two lateral slopes 6331 of the push block 633 respectively abut against the second ends of the rock arms 623 . Accordingly, when the bar member 632 is moved to the first position, the push block 633 is urged to move toward the first ends of the rock arms 623 and interpose between the second ends thereof. At this time, the two lateral slopes 6331 push the second ends of the rock arms 623 away from each other to make the clamping members 624 move to the clamping position. When the bar member 632 is moved to the second position, the push block 633 is moved from between the second ends of the rock arms 623 . At this time, the resilient member 625 applies a resilient force to the rock arms 623 to restore the clamping members 624 to the releasing position.
The drive section 64 has a linear actuator 641 mounted on the bed 20 . The drive section 64 has a power output shaft normal to an axis of the shaft 50 . The drive section 64 has a connection rod 642 having a first end and a second end. The first end of the connection rod 642 is perpendicularly fixedly connected with the power output shaft of the actuator 641 . The second end of the connection rod 642 extends into a slide slot 6321 formed at the second end of the bar member 632 and is slidable within the slide slot 6321 .
Accordingly, the drive section 64 can drive the push block 633 of the link section 63 to push and move the clamping members 624 to the clamping position where the linings 6242 tightly abut against two faces of the disc 61 . Under such circumstance, the disc 61 is restrained against rotation to provide braking effect for the shaft 50 . Reversely, the drive section 64 can also drive the push block 633 of the link section 63 to release the rock arms 623 from the push force. At this time, the resilient member 625 pulls the rock arms 623 to restore the clamping members 624 to the releasing position. Under such circumstance, the shaft 50 is permitted to freely rotate again.
It should be noted that in the first brake assembly 60 , the link section 63 is a second-class lever in which the point of resistance is between the fulcrum and the point of effort. Therefore, the force applied to the link section 63 by the actuator 641 is always smaller than the force exerted onto the clamping section 62 to provide braking effect for the shaft 50 . Moreover, the push block 633 has two lateral slopes for pushing the rock arms 623 . Therefore, only a little effort is required for providing braking effect for the shaft. In comparison with the conventional technique, the shaft brake mechanism of the present invention has power-saving and energy-saving effect.
The second brake assembly 70 includes a hoof section 71 annularly disposed on the shaft 50 and synchronously rotatable with the shaft 50 . The second brake assembly 70 further includes a ring-shaped drum 72 fixedly mounted on the second pier 40 and positioned around the hoof section 71 with the shaft 50 coaxially passing through the drum 72 . The shaft 50 can be restrained against rotation under frictional force between the hoof section 71 and an inner circumference 721 of the drum 72 .
To speak more specifically, the hoof section 71 has an annular plate-like base 711 coaxially fitted around and fixed with the shaft 50 . The hoof section 71 further has three hoofs 712 each having a pivot shaft 713 . The hoofs 712 are respectively pivotally mounted on the base 711 via the pivot shafts 713 and positioned around the shaft 50 at equal angular intervals. That is, the hoofs 712 are arranged in a pattern centered at the axis of the shaft 50 with the pivot shafts 713 positioned at 120-degree intervals. The axes of the pivot shafts 713 are parallel to the axis of the shaft 50 . Accordingly, the hoofs 71 can be pivotally rotated between a braking position and a releasing position. A resilient member 714 such as an extension spring is bridged between each two adjacent hoofs 712 for resiliently restoring the hoofs 712 from the braking position to the releasing position.
Each hoof 712 has a substantially arc-shaped hoof plate 7121 pivotally disposed on the pivot shaft 713 and a lining 7122 attached to a face of the hoof plate 7121 that faces the inner circumference 721 of the drum 72 . Accordingly, when the hoofs 712 are positioned in the braking position, the linings 7122 tightly attach to and abut against the inner circumference 721 of the drum 72 to apply a dynamic frictional force to the drum 72 . Under such circumstance, the shaft 50 is restrained against rotation.
When the hoof section 71 is synchronously rotated with the shaft 50 under wind power, a centrifugal force is created in direct proportion to the rotational speed of the shaft 50 . When the rotational speed of the shaft 50 is approximate to a nominal upper limit t 1 , the centrifugal force will overcome the pulling force of the resilient members 714 to make the hoofs 712 move from the releasing position to the braking position. The higher the rotational speed is, the tighter the linings 7122 abut against the inner circumference 721 and the greater the frictional force is, that is, the greater the resistance against the rotation of the shaft 50 is. Accordingly, the second brake assembly 70 can naturally restrain the rotational speed of the shaft 50 from proportionally increasing with the wind speed. As shown in FIG. 10B , without modifying the nominal upper limit t 1 of rotational speed, the nominal upper limit of operational wind speed can increase from t 2 to t 3 . Therefore, the operation time of the wind power generator can be prolonged to more efficiently utilize natural resource and increase total power generation capacity of the wind power generator.
The above embodiment is only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiment can be made without departing from the spirit of the present invention. | A shaft brake mechanism of wind power generator, including a first brake assembly and a second brake assembly independent from each other. The first brake assembly serves to provide braking effect for the shaft of the wind power generator against rotation. The second brake assembly serves to naturally restrain the rotational speed of the shaft from exceeding a nominal upper limit of rotational speed. Accordingly, the wind power generator can still safely operate in a situation that the wind speed exceeds a nominal upper limit of wind speed. Therefore, the wind speed range for the operation of the wind power generator is widened to increase the total power generation capacity thereof. | 5 |
This is a continuation of copending application Ser. No. 07/471,997 filed on Jan. 16, 1990, now U.S. Pat. No. 5,071,600.
BACKGROUND OF THE INVENTION
This invention relates to the preparation of thermally stable, substantially polycrystalline silicon carbide ceramic fibers derived from a polycarbosilane resin. The unexpected thermal stability of these fibers is achieved by the incorporation of boron prior to ceramification.
Silicon carbide ceramic fibers are well known in the art for their mechanical strength at high temperatures. As such, they have found a broad array of utilities such as reinforcement for plastic, ceramic or metal matrices to produce high performance composite materials or the formation of fibrous products such as high temperature insulation, belting, gaskets and curtains.
Several methods have been developed to manufacture such fibers. For instance, it is well known that organosilicon polymers may be spun into a fiber, infusibilized (cured) to prevent melting and ceramified at elevated temperatures. Unfortunately, this method often introduces substantial amounts of oxygen or nitrogen into the fiber through incorporation in the polymer or introduction during spinning, infusibilization or ceramification. When these fibers are heated to temperatures above 1400° C., the oxygen and nitrogen is lost causing weight loss, porosity and decreased tensile strength.
Recently, polycarbosilane preceramic polymers which have a Si-C skeleton have been utilized to minimize the incorporation of nitrogen and oxygen. Yajima et al. in U.S. Pat. Nos. 4,052,430 and 4,100,233, for example, teach a method of producing silicon carbide fibers by spinning, infusibilizing and pyrolyzing various polycarbosilanes. Nippon Carbon Co., moreover, utilize this technology to produce a SiC ceramic fiber under the trade name NICALON™. These fibers too, however, are known to contain about 9-15% oxygen and, thus, degrade at temperatures as low as 1200° C. (see Mah et al., J. Mat. Sci. 19, 1191-1201 (1984)
The addition of other elements to polycarbosilanes has also been suggested as a means to improve the mechanical strength of SiC based bodies. For example, Yajima et al. in U.S. Pat. No. 4,359,559 disclose the production of polymetallocarbosilanes by mixing a polycarbosilane with a titanium or zirconium containing organometallic compound. Similarly, Yajima et al. in U.S. Pat. No. 4,347,347 teach the formation of an organometallic block copolymer composed of a polycarbosilane portion and a polymetallosiloxane portion wherein the metallic element is titanium or zirconium. Yajima et al. in U.S. Pat. No. 4,342,712 also teach the formation of titanium, silicon and carbon-containing ceramic fibers from a block copolymer of polycarbosilane and a titanoxane.
Yajima et al. in U.S. Pat. No. 4,248,814 teach a process for producing ceramic bodies comprising (1) preparing a polycarbosilane partly containing siloxane bonds by heating a mixture of a polysilane with 0.01 to 15 weight percent polyborosiloxane, (2) mixing the resultant polycarbosilane with a ceramic powder and (3) sintering at a temperature of from 800° C. to 2000° C. This process, however, fails to teach the formation of ceramic fibers.
Yajima et al. in U.S. Pat. Nos. 4,220,600 and 4,283,376 teach the formation of a polycarbosilane partly containing siloxane bonds by a process comprising adding 0.01 to 15 weight percent polyborosiloxane to a polysilane and then heating. This polycarbosilane can then be spun, cured and pyrolyzed to form silicon carbide ceramic fibers. Pyrolysis temperatures up to 1800° C. are disclosed in the reference but the examples only teach pyrolysis up to 1300° C.
The incorporation of these elements, however, is often accompanied by various problems. For instance, high temperature and pressure is often necessary to cause the incorporation. The yields of the resulting polymers are often low. Additionally, the elements often bond to the silicon though intermediate oxygen linkages so that increasing amounts of oxygen are present in the polymer. Further, silicon carbide based fibers so produced are typically composed of extremely fine crystalline grains; heating the fibers to temperatures of 1300° C. or higher causes growth of the grains which results in a decrease in mechanical strength of the fibers.
Takamizawa et al. in U.S. Pat. No. 4,604,367 teach the preparation of an organoborosilicon polymer by mixing an organopolysilane with an organoborazine compound, spinning fibers and then ceramifying the fibers by heating to temperatures in the range of 900°-1800° C. However, the actual examples in this reference only show heating up to 1300° C. and the tensile strength of the fibers is reported to drop off dramatically when heated above 1500° C. (note the graph on the cover of the reference)
Takamizawa et al. in U.S. Pat. No. 4,657,991 teach the formation of SiC fibers by using a composition comprising a polycarbosilane and a silmethylene polymer which may be copolymerized with an organometallic compound containing boron, aluminum, titanium or zirconium. After spinning the above composition, the fibers are pyrolyzed to between 800° and 1500° C. The inventors therein teach that pyrolysis at temperatures above 1500° C. decreases the mechanical strength of the resulting fiber due to grain size growth.
The present inventors have now unexpectedly found that thermally stable, substantially polycrystalline SiC fibers can be formed from polycarbosilanes with greater than about 0.2% boron incorporated therein and firing said fibers to greater than about 1600° C.
SUMMARY OF THE INVENTION
The present invention relates to a method for the preparation of thermally stable, substantially polycrystalline silicon carbide fibers. The method may comprise initially forming a fiber from a preceramic polymer comprising a polycarbosilane resin with at least about 0.2% by weight boron incorporated therein. The fiber is next infusibilized to render it non-melting and then pyrolyzed at a temperature of greater than about 1600° C. in a nonoxidizing environment.
Alternatively, the method may comprise forming a fiber from a preceramic polymer comprising a polycarbosilane resin. The fiber is then infusibilized and/or pyrolyzed in a manner such that at least about 0.2% by weight boron is incorporated therein. The thus treated fiber is then pyrolyzed at a temperature of greater than about 1600° C. in a non-oxidizing environment.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is based on the discovery that polycarbosilane fibers which have at least about 0.2% by weight boron incorporated therein and which have been fired to a temperature greater than about 1600° C. form a substantially polycrystalline fiber which retains its strength at high temperatures. These fibers have at least 75% crystallinity, a density of at least about 2.9 gm/cc and a very low residual oxygen and/or nitrogen content.
The present inventors have found that both oxygen and nitrogen are eliminated from the fiber at temperatures above about 1400° C. which is believed to result in an initial weakening of the fiber. However, when boron is incorporated into fibers and said fibers are pyrolyzed above about 1600° C., it is believed the fibers undergo a densification process which decreases porosity and strengthens the fiber.
The boron may be incorporated into the fibers of the invention either prior to fiber formation and/or during at least one of the infusibilization step or the initial heating period for pyrolysis. The amount of boron necessary to achieve the desireable characteristics of such fibers is at least about 0.2% by weight with at least about 0.6% by weight being more preferred. Furthermore, it is desirable that the boron in the fibers be substantially uniformly distributed throughout the fibers. Each method of incorporation will be discussed in more detail infra.
The preceramic polymers used in the practice of this invention are polycarbosilane resins which contain a Si-C skeleton. Suitable polymers are described, for instance, by Yajima et al. in U.S. Pat. Nos. 4,052,430 and 4,100,233, both of which are incorporated herein in their entirety. The preferred polycarbosilane contains repeating (--SiHCH 3 --CH 2-- ) units and can be purchased commercially from the Nippon Carbon Co.
If boron is to be incorporated prior to formation of the fiber, a boron-containing compound may, for example, be included in the polymerization process or said compound may be reacted into the polycarbosilane after its formation. Alternatively, a boron-containing compound may be simply uniformly mixed with the polycarbosilane prior to spinning.
The above polymers useful in the invention are generally solids at room temperature, can be readily spun into small diameter fibers, can be rendered infusible such that the polymer will remain in fiber form during pyrolysis, and will yield a ceramic composition in which the carbon to silicon ratio is slightly greater than 1 to 1. More preferably, these solid polymers have softening points less than about 100° C., thereby rendering them readily extrudable for conventional fiber spinning techniques.
Alternatively, a liquid polycarbosilane may be utilized to spin the fibers. However, when fibers are spun in this manner, they are generally solidified by rapid curing immediately after exiting the spinning apparatus.
The polycarbosilanes may be formed into fibers by any conventional spinning technique. For instance, such techniques as melt spinning, dry spinning or wet spinning may all be used in the practice of this invention.
The spun fibers formed in this manner are then generally drawn to diameters of less than about 100 micrometers. More preferably, said fibers are drawn to diameters of about 10-50 micrometers. Fibers of this size are generally more flexible than larger fibers and, thus, can be more readily woven into reinforcing matrices for composite materials.
The fibers formed above are then infusibilized to prevent melting during pyrolysis. If no boron is to be incorporated during this process, the fibers may be infusibilized, for example, by simply heating them to a temperature in the range of about 50° to about 200° C. in air. Alternatively, said fibers may be infusibilized by exposure to gamma irradiation, ultraviolet light or an oxidizing agent such as nitric oxide.
Preferably, however, the boron is incorporated into the fibers during said infusibilization step by exposure to a boron containing gas. This may be accomplished at relatively low temperatures of between about 25° to about 200° C. and below the softening point of the polymer. While the use of higher temperatures may increase the rate of infusibilization, exceeding the softening point of the polymer during this process may destroy the integrity of the fiber. It has, however, been found that as the cure proceeds, the softening temperature of the polycarbosilane increases so that the curing temperature may be raised as the polymer cures. The exposure time necessary to cure the fibers is variable depending on the cure gas, the polymer utilized, the diameter of the fibers and the concentration of boron in the curing atmosphere.
In one embodiment of the invention, the spun fiber is exposed to a diborane-containing gas which diffuses into the surface of said fibers and through to their cores and deposits boron therein at a temperature of from about 50° to about 200° C. Diborane concentrations of from about 0.01 to about 1.0 percent by volume diluted in an inert gas such as argon have been found to provide an atmosphere which will infusibilize the fiber while incorporating the desired concentrations of boron. Exposure to the above atmosphere should be for a time sufficient to permit the boron to diffuse substantially uniformly throughout the fiber to provide concentration levels of at least about 0.2% by weight.
In a second embodiment of the invention, the spun fiber is infusibilized by sequential exposure to a boron containing gas such as boron trifluoride, boron tribromide or boron trichloride and then to an amine such as ammonia. Preferably, both the boron containing gas and the amine gases are diluted in an inert gas such as argon or nitrogen. The boron containing gas is preferably present in the curing atmosphere at a concentration in the range of from about 10 to about 30% by volume and the amine is preferably present in the range of from about 1 to about 15% by volume. The fibers are generally exposed to these environments at a temperature in the range of about 25° to about 200° C. for a period of from about 4 to about 24 hours.
In a third embodiment of the invention, the spun fibers may be cured by exposure to an atmosphere containing nitric oxide followed by exposure to an atmosphere containing boron trichloride or diborane. Nitric oxide concentrations in the range of from about 1 to about 10% by volume diluted in an inert gas such as argon have been found to be useful when followed sequentially by exposure to either boron trichloride or diborane in the concentrations set forth supra. (The nitric oxide cure process is generally described in U.S. Pat. No. 4,847,027 which is incorporated herein in its entirety) The fibers are generally exposed to these environments at a temperature in the range of about 25° to about 200° C. for a period of from about 4 to about 24 hours.
After infusibilization, the fibers are pyrolyzed by heating to temperatures greater than about 1600° C., and preferably at a temperature of about 1800°-1850° C. in a non-oxidizing environment. It has been found that both oxygen and nitrogen are eliminated from the fibers at temperatures above about 1400° C. which is believed to result in an initial weakening of the fiber. However, upon reaching temperatures in excess of about 1600° C., it is believed the fibers undergo a densification process which decreases porosity and strengthens the fiber. Temperatures in excess of about 2000° C. are not preferred as there is undesirable grain size growth of the silicon carbide ceramic which adversely affects fiber strength.
The time for which the fibers are held at a particular maximum temperature should be sufficient to reduce oxygen and/or nitrogen content of the fibers to below about 0.5% by weight. For example, if the fibers are heated to about 1800° C., it has been found that temperature should be maintained for about 1 hour.
If boron is to be incorporated into the fibers during pyrolysis, it may occur during the initial stages of this process. For instance, the boron may be incorporated by exposure to a boron containing gas such as diborane during the time that the fibers are being heated up to the temperature at which pyrolysis and ceramification begins.
Typically, pyrolysis becomes significant at about 400° C. so that as the polymer is subjected to temperatures above about 400° C., the incorporation of boron becomes increasingly difficult. Accordingly, if boron is incorporated after the infusibilizing step, it is preferred to treat the fibers with a boron containing gas at a temperature below about 400° C. for a time sufficient for the desired amount of boron containing gas to diffuse into the fibers.
The boron containing gases which may be incorporated during the early stages of pyrolysis may include, for example, diborane or various other boron hydrides such as tetraborane or pentaborane, borazine and/or trichloroborazine. These compounds are generally utilized in small concentrations and diluted in inert gases as described supra. The fibers are generally exposed to these atmospheres at temperatures in the range of from about 50° to about 500° C. for about 1 to about 24 hours. After this period, the pyrolysis proceeds as described supra.
In addition to the methods described above, it is also within the scope of this invention to incorporate boron during more than one of the above steps (for example, during polymerization and during infusibilization) as well as in any other manner which would produce fibers with at least about 0.2% boron by weight.
The ceramic fibers which result from the process of this invention have at least 75% crystallinity and have a density of at least about 2.9 gm/cc, which represents about 90-95% of the theoretical density of SiC. The fibers also have a smooth surface structure and a grain size less than 0.5 micrometers, typically less than 0.2 micrometers. Virtually all of the oxygen and/or nitrogen originally present in, or introduced into, the fibers is removed by the high temperature pyrolysis step. Less than about 0.5%, and preferably less than about 0.2%, by weight oxygen and/or nitrogen remain.
The following non-limiting examples are included in order that one skilled in the art may more readily understand the invention.
The polycarbosilane utilized in the following examples was obtained from Nippon Carbon Co. It was dissolved in hexane, filtered through a 0.2 micron filter and dried before spinning. Argon, nitrogen and ammonia were obtained from Scott Specialty Gases. Boron Trichloride was obtained from Matheson Gas. All firings were performed on a tray made from Grafoil™ (Union Carbide). The Grafoil™ was fired up to 1200° C. for 2 hours in argon prior to use.
Cures were performed on a manifold with three gas/vacuum inlets (the mixing chamber) connected to a 1 inch inside diameter tubular Pyrex™ or quartz reactor (the curing chamber) with an outlet end oil bubbler. Gas flow was measured via flow meters. Teflon™ tubing was employed to transport gases to the mixing chamber. Pyrolyses were carried out in a Lindberg 2 inch or 4 inch inside diameter tubular furnace under argon with a standard ramp rate of 1° C./minute from ambient temperature to 1200° C.
High temperature pyrolysis studies were conducted under argon in a 2 inch Astro graphite tube furnace. High temperature pyrolysis runs were performed at 1800° C. under argon for 1 hour and were always preceded by a burn-out run.
All fiber testing was performed on an Instron 1122 machine. Elemental analyses were carried out on a CEC 240-XA elemental analyzer and oxygen analyses were carried out on a LECO analyzer. Scanning Electron Microscopy evaluation was performed on a Joel T300 at 15 Kev accelerating voltage.
EXAMPLE 1
A sample of polycarbosilane resin was melt spun at about 280° to about 320° C. on an in-house monofilament device with an orifice diameter of 0.01 inch and extruded therefrom.
The formed fibers were infusibilized by sequential treatment with BCl 3 and ammonia. During the initial phase, the fibers were treated with BCl 3 diluted in argon (volume ratio of 0.15 BCl 3 :0.35 Ar) while heating from 25° to 140° C. over 4 hours. The resultant fibers were cooled to ambient temperature and then further treated with ammonia diluted in argon (volume ammonia to argon ratio of 0.15:1.0) for 15 hours. The infusibilized fibers were pyrolyzed to 1200° C. under argon at a rate of 1° C./minute. The black fibers which were produced were easily separable and had an average tensile strength of 215±49 Ksi, elastic modulus of 25.0±3.1 Msi and diameters of 7.7±0.5 micrometers.
The infusibilized fibers were then further pyrolyzed in an argon atmosphere at 1800° C. for 1 hour to produce separable black fibers which had become well densified. The ceramic fibers had an average tensile strength of 236±72 Ksi, elastic modulus of 32.0±2.4 Msi, diameters of 6.8±0.2 micrometers and densities in the range of about 2.8 to about 2.94 g/cc. The crystallite size was between about 500 to about 600 angstroms. (compared to Nicalon™ which produces crystallites larger than 1000 angstroms under similar conditions) As can be seen, the mechanical strength of the fibers was not adversely affected by pyrolysis at 1800° C.
For comparison, Nicalon fiber was pyrolyzed to 1800° C. under the same conditions described above. The resultant fibers crystallized and barely retained their physical integrity. The fibers were too weak to be tested.
EXAMPLE 2
A sample of polycarbosilane resin was melt spun in the same manner as Example 1. The formed fibers were infusibilized by sequential treatment with NO and diborane. During the initial phase, the fibers were treated with NO diluted in argon (volume ratio of 0.1 NO:2.0Ar) while heating from 25° to 200° C. over 24 hours. These fibers were then transferred to a Lindberg furnace and subjected to diborane treatment at 180° C. The infusibilized fibers were pyrolyzed from 180° to 1200° C. under argon at a rate of 1° C./minute. The black fibers which were produced were separable and had an average tensile strength of 247±47 Ksi, elastic modulus of 27.7±1.3 Msi and diameters of 7.4±0.2 micrometers.
The infusibilized fibers were then further pyrolyzed in an argon atmosphere at 1800° C. for 1 hour to produce black fibers. The ceramic fibers had an average tensile strength of 164±47 Ksi, elastic modulus of 25.7±1.3 Msi, and diameters of 6.9±0.0 micrometers.
For comparison, Nicalon fiber was pyrolyzed to 1800° C. under the same conditions described above. The resultant fibers crystallized and barely retained their physical integrity. The fibers were too weak to be tested.
EXAMPLE 3
A sample of polycarbosilane resin was melt spun in the same manner as Example 1. The formed fibers were infusibilized by sequential treatment with NO and BCl 3 . During the initial phase, the fibers were treated with NO diluted in argon (volume ratio of 0.1 NO:2.0 Ar) while heating from 25° to 200° C. over 24 hours. These fibers were cooled to room temperature and then treated with BCl 3 diluted in argon (volume ratio of 0.15 BCl 3 :0.35 Ar) while heating from 25° to 140° C. over 4 hours. The infusibilized fibers were pyrolyzed from 180° to 1200° C. under argon at a rate of 1° C./minute. The black fibers which were produced were separable and had an average tensile strength of 271±63 Ksi, elastic modulus of 25.9±1.9 Msi and diameters of 8.8±0.3 micrometers.
The infusibilized fibers were then further pyrolyzed in an argon atmosphere at 1800° C. for 1 hour to produce black fibers. The ceramic fibers had an average tensile strength of 243±19 Ksi, elastic modulus of 39.1±1.6 Msi, and diameters of 7.8±0.2 micrometers. | This invention relates to the preparation of thermally stable, substantially polycrystalline silicon carbide ceramic fibers derived from a polycarbosilane resin. The unexpected thermal stability of these fibers is achieved by the incorporation of boron prior to ceramification. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a drive shaft serving for the pivoting of the reed teeth about a pivot for a wave-type loom in which the reed teeth are formed of elongated thin blades, the wide sides of which are perpendicular to the shaft and which have one edge resting against the shaft.
Wave-type or undulating looms with blade-shaped reed teeth are known in which the latter are so moved by means of screw shafts, i.e. drive shafts which have a helical profile, that they as a whole carry out an undulatingly progressive movement and thereby beat the filling threads against the fell of the cloth. It is also known to use the undulatingly progressive movement of the reed teeth simultaneously for advancing the filling thread insertion members or shuttles.
In these undulating looms, the blade-shaped reed teeth have their wide sides perpendicular to the screw shafts which swing or pivot them about a pivot shaft around which they swing to lie with their narrow sides on the drive shafts. Accordingly, there is the danger that during the course of operation the blades will gradually work their way into the drive shafts producing thin grooves in the latter. As a result, the amount of swing or pivoting motion of the blades becomes inaccurate which in turn causes an irregular beat-up of the cloth.
It has been attempted to produce screw shafts of steel and provide them with a hardened chrome layer in order to prevent the formation of grooves. This measure however has failed to produce the desired results. In particular it has been found that in the case of metal reed teeth, contact rust is formed or wear of the reed teeth takes place.
For this reason screw shafts whose outer layer consists of plastic have been employed. If the plastic is arranged over an inner core of metal in such a shaft, the shaft is imparted the necessary strength. However, the blades still cut-in to such an extent that the life of the screw shaft must be considered insufficient for use on a loom. Since the reed teeth extend between the warp threads, when one of the customary types of lubrication is used, the cloth to be formed is dirtied. Furthermore, a resinification of the reed teeth takes place whereby the movement of the reed teeth is strongly impeded with the result that an increased load is exerted on the screw shaft by the reed teeth during operation.
The closest prior art known to applicants in connection with this application is U.S. Pat. No. 3,687,171.
SUMMARY OF THE INVENTION
The above discussed disadvantages are avoided by the present invention. The invention is characterized by the fact that the drive shaft for the swinging or pivoting of the reed teeth of a traveling wave or an undulating loom is provided with at least one groove which extends along the length of the shaft, and that a supply of a lubricant is present within the groove.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in further detail on the basis of the following examples and with reference to the drawings, in which:
FIG. 1 shows a vertical cross-sectional view through an arrangement of swingable reed teeth;
FIGS. 2 and 4 show side views of portions of screw shafts for producing the swinging of the reed teeth;
FIGS. 3 and 5 show cross-sectional views of screw shafts according to FIGS. 2 and 4, respectively, taken at right angles to the run of the screw shafts;
FIG. 6 is a cross-sectional view through the axis of rotation of the reed teeth;
FIGS. 7 and 8 show cross-sectional views which show further developments of the shaft in accordance with the invention; and
FIG. 9 shows a side view of a portion of the screw shaft of FIG. 8.
DESCRIPTION OF PREFERRED EMBODIMENTS
A large number of reed teeth 12 are arranged swingable about a pivot shaft 11 which is shown in cross-section in FIG. 1. Reed teeth 12 have the shape of thin elongated blades whose wide sides are positioned perpendicular to the pivot shaft 11, the reed teeth being positioned at small regular distances from each other. Two screw or reed teeth drive shafts 13, 14 serve to swing or pivot the reed teeth 12 about pivot axis 11. Each of these screw shafts is provided with a profile 15, 16 which extends helically along the shaft (see FIGS. 2 and 4). In this connection the profiles 15, 16 of the shafts 13 and 14 supplement each other in the manner that upon their rotation in the direction indicated by the arrows 21, they continuously rest against the reed teeth 12 whereby the latter are always held and positively guided in their swinging movements as they are pivoted around the shaft 11.
The reed teeth 12 extend through the shed formed by warp threads 17. Between adjacent reed teeth 12 there are arranged one or more warp threads 17. A large number of sheds is present over the width of the loom. In each individual shed there is provided a filling introduction member or shuttle 18. The woven cloth is designated by 19.
In addition to the beating-up of the filling threads, the movement of the reed teeth 12 towards the cloth can also be used for the advancing of the shuttles 18. For this purpose the shuttles are provided with an oblique rear edge. When the reed teeth 12 strike against this rear edge, they force the shuttles 18 forward. The movement of the reed teeth 12 towards the cloth serves in particular for the beating of the filling threads coming from the shuttles 18 against the fell of the cloth. For this beating-up of the filling threads, a considerable force must be exercised on the reed teeth 12 by the screw shaft 13. During the operation of the loom, this force represents the greatest load acting on the screw shaft 13.
In FIG. 2 a portion of a screw shaft 13 is seen as viewed from the side. The screw shaft 13 consists of a center piece 20 of metal which is surrounded by a jacket 22 consisting of plastic. (See FIG. 3.) The profile 15 serves to produce swinging movements of the reed teeth 12. For the sake of completeness, a single reed tooth 12 is also included in the drawing. The metal center piece 20 is not shown in FIG. 1.
When the shafts 13, 14 turn in the direction of rotation indicated by the arrow 21 when the loom is in operation, the reed teeth 12 are thereby caused to carry out swinging motions which take place around the pivot axis 11. The extreme positions of the reed teeth 12 are shown in dash-dot line and designated A and B. The swinging motion of the reed teeth 12 in the direction towards the cloth 19 is effected by the pressing of the profile 15 against the reed tooth 12 and the movement of the reed tooth 12 away from the cloth 19 takes place by the pressing of the profile 16 against the reed tooth 12. As a result of this manner of operation, grooves can in time be produced on the surface of the screw shafts 13, 14 or in the pivot shaft 11.
As mentioned at the start, different types of solution were tried out, in which connection the idea of effecting the beating-up of the filling thread by means of rotating disks also came up. As compared with this, however, swinging reed teeth 12 have the substantial advantage that they strike the filling thread with a movement which is perpendicular to the cloth 19 and the beating edge and that the warp threads 17 remain at all times between the reed teeth 12 so that the dipping of disk parts between the warp threads, necessary upon each rotation in the case of rotating disks, together with the great disadvantages caused thereby are not present.
It has now been found that a great increase in the life of the shafts 11, 13, and 14 is obtained if only extremely slight lubrication is provided. In this connection, it has been found that a minimal dosaging of the lubricant must be used for the lubrication. To accomplish this, a groove 24 is arranged in the screw shaft 13 and a wick-like lubricant holder is inserted in the groove 24, it being impregnated with a lubricant. The lubricant holder must be of such a nature that it contains as much lubricant as possible but only gives off an extremely small amount of lubricant. A lubricant holder in the form of a stuffing box packing consisting of textile braid which has a relatively dense surface has proven advantageous. The amount of lubricant therein can amount to more than 50% of the volume of the support. It may consist of flexible material but should be as resistant as possible to wear.
As already mentioned, the greatest pressure on the reed teeth 12 is necessary for the beating-up of the filing thread. It is most advantageous for the groove 24 to be arranged directly in front of the point of greatest pressure. In the embodiment shown in FIGS. 2 and 3, the reed tooth 12 rests against the screw shaft 13 in the region 25, when the beating-up of the thread takes place. With the direction of rotation indicated by 21, the groove 24 containing the lubricant is accordingly somewhat in front of this region 25 whereby the lubricant is transferred upon each revolution from the groove 24 to the reed tooth 12 and from the reed tooth to the region of action 25.
In FIGS. 4 and 5 the screw shaft 14 is shown. Over a metal center 26 there is arranged a jacket 27 of plastic having the profile 16. In the groove there is similarly present a holder or holder means impregnated with a lubricant, said holder advantageously also being in the shape of a wick-like structure.
In the case of the screw shaft 14, the greatest load is present when the reed tooth 12 is accelerated out of its beating-up position, i.e. in the region 31. However, directly in front of this region as referred to the direction of rotation 21, the jacket 27 is relatively thin so that it is advisable to move the groove 30 forward to such an extent that it comes to lie in a relatively thicker part of the jacekt 27. The transfer of the lubricant from the groove 30 via the reed tooth 12 to the region of pressure 31 is nevertheless assured.
Upon the swinging movements of the reed teeth 12, an edge of the reed teeth rests or abuts with friction also against the shaft 11. It is therefore advisable to provide a similar lubrication for this shaft 11. As shown in FIG. 6, the shaft 11 is provided with two grooves 32 which extend parallel to the axis 37 of the shaft 11 and are arranged opposite each other with respect to the shaft, and in each of which there is a lubricant holder. In this connection it may be mentioned that the conditions in connection with the shaft 11 are less critical. This is due to the fact that the relative speed between the edge of the blade 12 resting on the shaft and the surface of the shaft 11 is smaller than in the case of the shafts 13, 14.
It has been found, particularly in the case of the screw shafts 13, 14, that after a certain period of operation of for instance several months, the lubricant has migrated to the outside and the lubricant support has become dry, particularly in its inner region. It appears that the centrifugal force caused by the rotation plays an essential part in this. Another advantageous embodiment thus provides a special storage space for lubricant.
FIG. 7 shows the lubricant support or holder means 33 located in the groove 24. Along the inner side or bottom surface of the groove 24 there is provided a second groove 34 serving as storage space and extending parallel to the groove 24. The groove 34 is filled with a lubricant 35 so that the latter passes slowly during the operation of the loom through the wick 33 of the lubricant holder means and contributes to a proper amount of lubrication being automatically dispensed.
Another example of a storage space for lubricant is shown in FIGS. 8 and 9. In FIG. 9 the lubricant holder is not shown. In accordance with this example bore holes 36 are provided at relatively small distances apart along the groove 24, lubricant 35 being introduced into said bore holes. In this case also during the operation of the loom, the lubricant migrates slowly towards and into the lubricant holder means 33. There it distributes itself in the longitudinal direction of the holder means as a result of capillary forces.
As lubricant there is recommended in particular one that evaporates as slowly as possible. Furthermore, it should be as resistant chemically as possible and be adapted to the material of which the screw shaft is made. For this purpose highly viscous greases are suitable, such as for instance those employed for vacuum pumps. Greases which contain natural wax or paraffin wax have also proven suitable.
Polyoxymethylene type plastic has proven to be particularly suitable as material for the jackets 22, 27 as well as for the shaft 11.
It will be appreciated that various changes and modifications may be made within the skill of the art without departing from the spirit and scope of the invention illustrated, described, and claimed herein. | Shaft arrangement for the swinging of reed teeth in a wave-type loom in which at least one lubricating groove extends the length of the shaft that drives the swinging of the reed teeth. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to a method for fluorinated compounds, fluorinated compounds produced by the method, fluorinated polymers obtained from the fluorinated compounds, and optical or electrical materials using the fluorinated polymers.
[0003] 2. Related Art
[0004] Fluorinated polymers are useful materials that are used in various applications, for example, plastic optical fibers and photoresist materials, or surface modifiers. However, the synthetic processes of fluorinated polymers are complicated and costly.
[0005] A fluorinated polymer is obtained by polymerization of a fluorinated compound having a polymeric unsaturated group. As an example of fluorinated polymers, 1,3-dioxolane derivatives and the like are disclosed in U.S. Pat. No. 3,308,107, U.S. Pat. No. 3,450,716; Izvestiya A Kademii Nank SSSR, Seriya Khimicheskaya. pp. 392-395, February 1988 by V. S. Yuminov et al. and pp/938-, April 1989 by V. S. Yuminov et al; and the like.
[0006] However, 1,3-dioxolane derivatives that have been conventionally known are limited to the structures of a compound represented by the following formula (A) disclosed in U.S. Pat. No. 3,978,030, a compound represented by the following formula (B) disclosed in JP-A No. 5-339255, and the like. In these compounds, only a specific substitutional group can be located at a specified site on a five-membered ring of dioxolane.
[0007] In Formula (B), R f 1′ and R f 2′ each independently represent a polyfluoroalkyl group having 1 to 7 carbon atoms.
[0008] Such structural limitation results from the synthetic processes employed to form the polymers. For example, in a conventional method for synthesis of the compound represented by the above formula (A), only one fluorine-containing group may be located on a 1,3-dioxolane ring, and the fluorine-containing group that can be introduced is limited to a trifluoroalkyl group. In a conventional method for synthesis of the compound represented by the above formula (B), one polyfluoroalkyl group that can be introduced into a 1,3-dioxolane ring is located at each site of 4- and 5-membered rings, that is, the number of polyfluoroalkyl group is inevitably limited to two in total. Further, a material used for synthesizing the fluorinated compound represented by formula (B) is a compound represented by the following formula (C), and it is difficult to synthesize such compound.
SUMMARY OF THE INVENTION
[0009] The present inventors have developed the following synthetic methods, therefrom have derived useful and novel fluorinated compounds, and optical or electrical materials using the polymers. The present invention will be described below.
[0010] A first aspect of the present invention is a method for producing a fluorinated compound represented by the following formula (3), the method comprising a step of fluorinating, in a fluorine-based solution under a fluorine gas atmosphere, a compound obtained by reacting at least one of kind of compound represented by the following formula (1) and at least one kind of compound represented by the follwing formula (2):
[0011] wherein in formula (1), X represents a hydrogen atom or a fluorine atom, and Y represents an alkyl group having 1 to 7 carbon atoms or a polyfluoroalkyl group having 1 to 7 carbon atoms; and in formula (2), Z represents a hydroxyl group, a chlorine atom, or a bromine atom, and R 1 to R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 7 carbon atoms or a polyfluoroalkyl group having 1 to 7 carbon atoms.
[0012] Wherein, in formula (3), R ff 1 to R ff 4 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms.
[0013] A second aspect of the present invention is the method for producing a fluorinated compounds according to the first aspect, wherein the fluorine gas atmosphere is a mixed atmosphere of nitrogen gas and fluorine gas, and a proportion of the nitrogen gas with respect to the fluorine gas is in a range from 2 to 4.
[0014] A third aspect of the present invention is the method for producing a fluorinated compounds according to the first aspect, wherein, in the step of fluorinating, a reaction temperature is kept in a range of 0 to 5° C., and stirring is carried out
[0015] A fourth aspect of the present invention is a fluorinated compound represented by the following formula (4):
[0016] wherein, in formula (4), R ff 1 and R ff 2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms, and n represents an integer from 1 to 4.
[0017] A fifth aspect of the present invention is a fluorinated polymer obtained by polymerization of the fluorinated compound according to the fourth aspect.
[0018] A sixth aspect of the present invention is an optical or electrical material comprising the fluorinated polymer according to the fifth aspect.
[0019] A seventh aspect of the present invention is an optical or electrical material according to the sixth aspect, wherein the optical material is an optical wave guide, an optical lens, a prisms, a photo mask, or an optical fiber.
[0020] A eighth aspect of the present invention is a compound represented by the following formula (5):
[0021] wherein, in formula (5) X represents a hydrogen atom or a fluorine atom, Y represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or a polyfluoroalkyl group having 1 to 7 carbon atoms, and R 1 to R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or a polyfluoroalkyl group having 1 to 7 carbon atoms.
[0022] A ninth aspect of the present invention is a compound represented by the following formula (6):
[0023] wherein, in formula (6), X represents a hydrogen atom or a fluorine atom, Y represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or a polyfluoroalkyl group having 1 to 7 carbon atoms, R 3 or R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or a polyfluoroalkyl group having 1 to 7 carbon atoms, and n represents an integer from 1 to 4.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a graph showing refractive indexes of polymers synthesized by Examples 2 and 4.
[0025] FIG. 2 is a graph showing the material dispersion of the polymer synthesized by Example 2.
[0026] FIG. 3 is a graph showing the optical transmission of the polymer synthesized by Example 4.
DETAILED DESCRIPTION OF THE INVENTION
[0000] 1. Method for Producing Fluorinated Compounds
[0027] A description will be given of a method for producing fluorinated compounds, that are 1,3-dioxolane derivatives, according to the present invention.
[0028] In the production method of the present invention, a fluorinated compound that uses 1,3-dioxolane derivatives, represented by the following formula (3), is produced using the following formulae (1) and (2) in a fluorine-based solution in a flow of fluorine gas.
[0029] In Formula (1), X represents a hydrogen atom or a fluorine atom. From the viewpoint of ready availability, X is preferably a hydrogen atom. Y represents an alkyl group having 1 to 7 carbon atoms, preferably 1 to 3 carbon atoms, or a polyfluoroalkyl group having 1 to 7 carbon atoms, preferably 1 to 3 carbon atoms, more preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Specially preferably, Y represents an alkyl group having 1 to 3 carbon atoms
[0030] In Formula (2), Z represents a hydroxyl group, chlorine atom, or bromine atom.
[0031] In Formula (2), R 1 to R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or an polyfluoroalkyl group having 1 to 7 carbon atoms. After the compound represented by Formula (1) and the compound represented by Formula (2) are made to react with each other, hydrogen atoms that form a product are all fluorinated. Therefore R 1 to R 4 may be hydrogen atom, alkyl group, or polyfluoroalkyl group. More preferably, R 1 to R 4 each independently represent a hydrogen atom, or an alkyl group having 1 to 7 carbon atom because of cost-effective. Specifically preferably, R 1 to R 4 each independently represent a hydrogen atom, or an alkyl group having 1 to 3 carbon atom. R 1 and R 2 may be bonded to each other to form a ring.
[0032] In Formula (3), R ff 1 to R ff 4 each independently represent a fluorine atom, or a perfluoroalkyl group having 1 to 7 carbon atoms. Preferably, R ff 1 to R ff 4 each independently represent a fluorine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms. R ff 1 and R ff 4 may be bonded to each other to form a ring.
[0033] Reaction schemes of these compounds are exemplified below, but the present invention is not limited to the same.
[0034] The production process of the present invention is broadly divided into, preferably, at least four steps as below.
(1) a step in which the compound represented by the above formula (1) and the compound represented by the above formula (2) are made to undergo dehydration or dehydro halogenation reaction; (2) a step in which the above compounds are fluorinated in a fluorine-based solution; (3) a step in which a carboxylate salt is produced by a base; and (4) a step of heating in order to decarboxylate the obtained carboxylate salt.
[0039] These four steps (1) to (4) will be described below in detail.
[0000] Step (1):
[0040] It is preferable that the compound represented by Formula (1) and the compound represented by Formula (2) are made to react with each other at an equimolar ratio. The compounds represented by Formula (1) may be used either singly or in combination of two or more. Further, the compounds represented by Formula (2) may be used either singly or in combination of two or more.
[0041] Moreover, since the above is an exothermic reaction, these compounds are preferably made to react with each other while being cooled. Other reaction conditions are not particularly limited, and prior to the subsequent step (2), a purification process such as distillation is also preferably added.
[0000] Step (2):
[0042] In this step, hydrogen atoms of the compound prepared by the step (1) are all substituted with fluorine atoms. To that end, preferably, the hydrogen atoms are directly fluorinated in a fluorine-based solution. As for such direct fluorination, refer to Synthetic Fluorine Chemistry, Eds by G. A. Olah, R. D. Chambers, and G. K. S. Prakash, J. Wiley and Sons. Inc. New York (1992), by R. J. Lagow, T. R. Bierschenk, T. J. Juhlke and H. kawa, Chaper 5: Polyether Synthetic Method.
[0043] The fluorine-based solution is not particularly limited. For example, 1,1,2-trichlorotrifluoroethane, polyfluorobenzene, and the like are preferable. Specific examples thereof include Fluorinert FC-75, FC-77, FC-88 (produced by 3M Corporation), and the like. The ratio of fluorine-based solution to the compound prepared by the step (1) is 2-10 times (mass ratio), more preferably, the ratio is 3-4 times.
[0044] The fluorination is carried with fluorine gas diluted with nitrogen gas. The ratio of nitrogen gas to fluorine gas is preferably 2-6 times (volume ratio), more preferably, the ratio is 2-4 times larger than fluorine gas.
[0045] The compound obtained through the step (1) is dissolved in the fluorine-based solvent (the weight ratio of the compound to the solution is 0.40-0.50). The solution is added slowly into the fluorine-based solution under F 2 /N 2 stream. The addition rate is preferably 0.3 ml/min. to 20 ml/min., more preferably 0.5 ml/min. to 10 ml/min.
[0046] The reaction of the step (2) is carried out by controlling temperature. The reaction temperature should be under 5° C., preferably at between 0° C. and 5° C. During step (2), the solution is preferably well stirred.
[0000] Step (3):
[0047] A carboxylate salt is produced from the fluorine compound obtained by step (2) by a base. As the base, potassium hydroxide, sodium hydroxide, cesium hydroxide, and the like are preferable. Potassium hydroxide is more preferable.
[0000] Step (4):
[0048] The obtained carboxylate salt is heated and decarboxylated. The heating temperature is preferably in the range of 250° C. to 320° C., and more preferably in the range of 270° C. to 290° C.
[0049] In the production method of the present invention, other steps in addition to the above steps (1) to (4) can be added.
[0000] 2. Method for Producing Fluorinated Polymers
[0050] The above fluorinated compound undergoes radical polymerization in accordance with an ordinary method, thereby allowing production of a fluorinated polymer. A peroxide is preferably used as a radical catalyst, but in order that a fluorine atom of the fluorine compound may not be substituted with a hydrogen atom, a perfluoroperoxide is used.
[0000] 3. Fluorinated Compound
[0051] In the production method of the present invention, a hydrogen atom can be substituted with a perfluoro group or a fluorine atom at an arbitrary site on a 1,3-dioxolane ring, and perfluoro-2-methylene-1,3-dioxolane represented by the following formula (3) can be obtained.
[0052] In Formula (3), R ff 1 to R ff 4 each independently represent a fluorine atom, or a perfluoroalkyl group having 1 to 7 carbon atoms. Preferably, R ff 1 to R ff 4 each independently represent a fluorine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms.
[0053] The compound represented by Formula (3) can be easily polymerized using a peroxide. Further, this compound has a five-membered ring and is a stable material. In the case of a six-membered ring, ring-opening is liable to occur at the time of polymerization, and therefore, a resulting polymer becomes a mixture. In this case, physical properties such as heat resistance are liable to deteriorate.
[0054] Further, a compound represented by the following formulae (4) is a novel compound.
[0055] R ff 1 and R ff 2 each independently represent a fluorine atom, or a perfluoroalkyl group having 1 to 7 carbon atoms, and n represents an integer of 1 to 4, preferably, an integer of 1 to 2.
[0000] 4. Method for Producing Fluorinated Polymers
[0056] The above fluorinated compound undergoes radical polymerization in accordance with an ordinary method, thereby allowing production of a fluorinated polymer. A peroxide is preferably used as a radical catalyst, but in order that a fluorine atom of the fluorine compound may not be substituted with a hydrogen atom, a perfluoroperoxide is used.
[0000] 5. Application of Fluorinated Polymer
[0057] A polymer obtained by polymerization of the compound represented by Formula (4) can be suitably used for optical or electrical materials. This polymer has a high glass transition temperature and it is amorphous material. Therefore, such polymer can be suitably used for plastic optical fibers, light wave guides, optical lenses, prisms, photo masks, and the like, more suitably used for plastic optical fibers, light wave guides material, optical lenses.
EXAMPLE 1
Synthesis of perfluoro-4-methyl-2-methylene-1,3-dioxolane
Preparation of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane
[0058] A 3L 3-necked flask equipped with a water-cooled condenser, a thermometer, a magnetic stirrer and a pressure-equalizing dropping funnel were made usable. The flask was charged with 139.4 g (1.4 mol) of a mixture of 2-chloro-1-propanol and 1-chloro-2-propanol. The flask was cooled to 0° C. and methyl trifluoropyruvate was slowly added thereto. After addition, the reaction mixture was stirred for additional 2 hours. Then 100 ml of DMSO and 194 g of potassium carbonate were further added during one hour. Stirring was continued for another 8 hours, thereby obtaining a reaction mixture. The reaction mixture obtained was poured into 1 L of water. Dichloromethylene extracts were combined with the organic phase. Subsequently, the reaction mixture was dried with magnesium sulfate. After removing the solvent, 245.5 g of crude product was obtained. The crude product was fractionally distilled at reduced pressure (12 Torr), and 230.9 g of pure product of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane was obtained. The boiling point of the pure product was 77 to 78° C., and the yield was 77%.
[0059] HNMR (ppm): 4.2 to 4.6, 3.8 to 3.6 (CHCH 2 , Multiplet, 3H), 3.85 to 3.88 (COOCH 3 , multiplet, 3H), 1.36 to 1.43 (CCH 3 , multiplet, 3H);
[0060] 19 FNMR (ppm): −81.3 (CF3, s, 3F).
Fluorination of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane
[0061] A 10 L stirring-reactor vessel was loaded with 4 liters of 1,1,2-trichlorotrifluoroethane. The nitrogen flow was set at 1340 cc/min and the fluorine flow was set at 580 cc/min, thereby making the interior of the stirring-reactor vessel under a nitrogen/fluorine atmosphere. After 5 minutes, 290 g of the prepared 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane was dissolved to 750 ml of 1,1,2-trichloro-trifluoroethane solution, and then this solution was added into the reactor at a rate of 0.5 ml/min. The reactor vessel was cooled to 0° C. After all the dioxolane was added over 24 hours, the fluorine flow was stopped. After purging with nitrogen gas, an aqueous KOH solution was added to the reactor until it turned to slight alkali.
[0062] After removing volatile materials under reduced pressure. The residue was further dried under reduced pressure at 70° C. for 48 hours, thereby obtaining a solid reaction product. The solid reaction product was dissolved in 500 ml of water and excess of hydrochloric acid was added to obtain two phases, that is, an organic phase and a water phase. The organic layer was separated and distilled under reduced pressure. As a result, perfluoro-2,4-dimethyl-1,3-dioxolane-2-carboxylic acid was produced. The boiling point of the main distillate was 103 to 106° C./100 mmHg. The overall fluorination yield was 85%.
Synthesis of perfluoro-4-methyl-2-methylene-1,3-dioxolane
[0063] Perfluoro-2,4-dimethyl-2-potassium carboxylate-1,3-dioxolane was obtained by neutralization of the above distillate with an aqueous KOH solution. The potassium salt was dried at 70° C. under vacuum for one day. The salt was decomposed with a stream of nitrogen or argon atmosphere at 250 to 280° C. to yield the product which was collected in a trap cooled to −78° C., thereby obtaining perfluoro-4-methyl-2-methylene-1,3-dioxolane (yield: 82%). The product had the boiling point of 45° C./760 mmHg, and was identified using 19 FNMR and GC-MS as below.
[0064] 19 FNMR: −84 ppm (3F, CF 3 ), −129 ppm (2F, ═CF 2 );
[0065] GC-MS: m/e244 (Molecular ion) 225, 197, 169, 150, 131, 100, 75, 50.
[0066] Synthetic schemes according to Example 1 are schematically shown below.
EXAMPLE 2
Polymerization of perfluoro-4-methyl-2-methylene-1,3-dioxolane
[0067] 100 g of perfluro-4-methyl-2-methylene-1,3-dioxolane and 1 g of perfluorobenzoyl peroxide were charged in a glass tube, which was then degassed and refilled with argon in two vacuum freeze-thaw cycles. The tube was sealed and heated at 50° C. for several hours. The content became solid. Further the tube was kept to be heated at 70° C. over night and 100 g of a transparent bar was obtained.
[0068] The transparent bar was dissolved in Fluorinert FC-75 (produced by 3M Corporation) and a thin film of polymer was obtained by casting the solution on a glass plate. The glass transition temperature of the polymer was 117° C. The polymer was completely amorphous. The transparent bar was purified by precipitation from the hexafluorobenzene solution by adding chloroform thereto. The glass transition temperature of the product was increased to 133° C.
[0069] The refractive indexes at various wavelengths were shown by the line of A in FIG. 1 , and the material dispersion of the polymer was shown in FIG. 2 . It can be seen from such refractive indexes that the obtained polymer is suitable for optical fibers, optical waveguides, and photo masks.
EXAMPLE 3
Synthesis of perfluoro-4,5-dimethyl-2-methylene-1,3-dioxolane
Synthesis of 2,4,5-trimethyl-2-carboxymethyl-1,3-dioxolane
[0070] A reaction mixture: 2.0 mol of 2,3-butanediol, 2.0 mol of methyl pyruvate, 10 g of a cation exchange resin (H form), and 1 L of absolute benzene were refluxed until no more water came to be produced in a flask fitted with a Dean-Stark trap, thereby obtaining 2,4,5-trimethyl-2-carboxymethyl-1,3-dioxolane. The yield was 75% and the boiling point of the product was 45° C./1.0 mmHg.
[0071] 1 HNMR: 1.3 ppm (6H, —CH 3 ), 1.56 ppm (3H, —CH 3 ), 3.77 ppm (3H, OCH 3 ), 3.5 to 4.4 ppm (m, 2H, —OCH—).
Synthesis of perfluro-2,4,5-trimethyl-2-carboxylic acid-1,3-dioxolane
[0072] 500 g of the obtained 2,4,5-trimethyl-2-carboxymethyl-1,3-dioxolane was fluorinated with fluorine gas diluted with nitrogen in Fluorinert FC-75 (trade name) as described in Example 1. After completion of the reaction, nitrogen gas was purged for 30 minutes. The obtained mixture was then treated with an aqueous KOH solution to form an organic phase and a slightly-alkaline water phase. The water of the water phase was removed under reduced pressure, and a solid material was thereby obtained. The solid material obtained was acidified with concentraded hydrochloric acid and distilled out, thereby obtaining perfluoro-2,4,5-trimethyl-2-carboxylic acid-1,3-dioxolane. The yield was 85%, and the boiling point was 61° C./2.5 mmHg.
Synthesis of perfluoro-4,5-dimethyl-2-methylene-1,3-dioxolane
[0073] Perfluoro-2,4,5-trimethyl-2-potassium carboxylate-1,3-dioxolane was obtained by neutralization of the above distillate with an aqueous KOH solution. The obtained potassium salt was dried at 70° C. under vacuum for one day. The salt was further decomposed with stream of nitrogen or argon at 250 to 280° C. to yield the product which was collected in a trap cooled to −78° C. As a result, perfluoro-4,5-dimethyl-2-methylene-1,3-dioxolane was obtained (yield: 78%). The boiling point of the product was 60° C. The product was identified using 19 FNMR and GC-MS.
[0074] 19 FNMR: −80 ppm (6F, —CF 3 ), −129 ppm (2F, ═CF 2 );
[0075] GC-MS: m/e294 (Molecular ion).
[0076] Synthetic schemes according to Example 2 are schematically
EXAMPLE 4
Polymerization of perfluoro-4,5-dimethyl-2-methylene-1,3-dioxolane
[0077] 10 g of the perfluoro-4,5-dimethyl-2-methylene-1,3-dioxolane obtained by Example 3 and 80 mg of perfluorobenzoylperoxide were charged in a glass tube, which was then degassed and refilled with argon in three vacuum freeze-thaw cycles. The tube was sealed and heated at 50° C. for one day. The content became solid and the tube was kept to be heated at 70° C. for 4 days. 10 g of a transparent bar was obtained.
[0078] The transparent bar was purified by dissolving a part thereof in a hexafluorobenzene solution and also by precipitation from a hexafluorobenzene solution with chloroform being added thereto. The yield was 98% or greater. Solution polymerization of the monomer was performed in Fluorinert FC-75 (trade name) using perfluorobenzoyl peroxide as an initiator.
[0079] 19 FNMR of the obtained polymer was −80 ppm (6F, —CF 3 ), −100 to −120 ppm (2F, main chain) and −124 ppm (2F, —OCF). The refractive indexes of the obtained polymer are shown by the line B in FIG. 1 , and the optical transmission thereof in the range of 200 to 2000 nm is shown in FIG. 3 . It can be seen from such refractive indexes and optical transmission that the obtained polymer is suitable for optical fibers, optical wave guides, and photo masks.
EXAMPLE 5
Synthesis of perfluoro-4,5-cyclotetramethylene-2-methylene-1,3-dioxolane
[0080] Synthesis of 2-methyl-2-methoxycarboxyl-4,5-cyclotetramethylene-1,3-dioxolane:
[0081] A reaction mixture: 100 g (1 mol) of 1,2-cyclohexanediol, 204 g (2 mols) of methyl pyruvate, 1.5 L of absolute benzene, and 10 g of a cation exchange resin (H form) was refluxed until no more water came to be produced in a flask fitted with a Dean-Stark trap. The cation exchange resin was removed by filtration. The product was distilled at 65° C./5 mmHg, thereby obtaining 2-methyl-2-methoxycarboxyl-4,5-cyclotetramethylene-1,3-dioxolane. The yield was 50 to 60%.
Fluorination of 2-methyl-2-methoxycarboxyl-4,5-cyclotetramethylene-1,3-dioxolane
[0082] The obtained 2-methyl-2-methoxycarboxyl-4,5-cyclotetramethylene-1,3-dioxolane was fluorinated in a fluorinated solvent, Fluorinert FC-75 (trade name) with F 2 /N 2 as described in Example 1. After completion of the reaction, by removing the solvent and produced hydrogen fluoride, and then treating the fluorinated product with an aqueous KOH solution, perfluoro-2-methyl-2-potassium carboxylate-4,5-cyclotetramethylene-1,3-dioxolane was obtained. The obtained potassium salt was dried by heating at 60° C. under reduced pressure (yield: 75%) and the dried potassium salt was decomposed at 250° C. in the nitrogen gas atmosphere. The product; perfluoro-4,5-cyclotetramethylene-2-methylene-1,3-dioxolane was collected in a trap cooled to −78° C. and the yield thereof was 85%. The boiling point of the product was 60° C. The product was identified using 19 FNMR and GC-MS.
[0083] 19 FNMR: −137 ppm (2F, ═CF 2 ), 126 to 134 ppm (8F, CF 2 ), −125 ppm (2F, OCF);
[0084] GC-MS: m/e360 (Molecular ion).
[0085] Synthetic schemes according to Example 5 are schematically shown below.
EXAMPLE 6
Polymerization of perfluoro-4,5-cyclotetramethylene-2-methylene-1,3-dioxolane
[0086] 10 g of the perfluoro-4,5-cyclotetramethylene-2-methylene-1,3-dioxolane obtained by Example 5 and 80 mg of perfluorobenzoyl peroxide were charged in a glass tube, which was then degassed and refilled with argon in two vacuum freeze-thaw cycles. The tube was sealed and heated at 50° C. for 12 hours. The content of tube became solid and the tube was kept to be heated at 70° C. over night. 10 g of a transparent rod was obtained.
[0087] The resulting polymer was completely amorphous and transparent. The refractive indexes of the polymer were 1.3160 (632.8 nm) and 1.3100 (1544 nm), and the glass transition temperature thereof was about 160° C.
[0088] 19 FNMR: −120 to −140 ppm (8F, CF 2 ), −100 to −118 ppm (2F, main chain), and 120 ppm (2F, —OCF). It can be seen from the viewpoint of a high glass transition temperature that the obtained polymer is less subject to heat deformation, and is suitable for electrical materials, optical fibers, optical wave guides, and the like.
EXAMPLE 7
Synthesis of perfluoro-4,5-cyclotrimethylene-2-methylene-1,3-dioxolane
Synthesis of 2-methyl-2-methoxycarboxyl-4,5-cyclotrimethylene-1,3-dioxolane
[0089] A reaction mixture: 102 g (1 mol) of 1,2-cyclopentanediol, 204 g (2 mols) of methyl pyruvate, 1.5 L of absolute benzene, and 10 g of a cation exchange resin (H form) was refluxed until no more than water came to be produced. After the cation exchange resin was removed by filtration, the product was distilled at 67° C./20 mmHg, thereby obtaining 2-methyl-2-methoxycarboxyl-4,5-cyclotrimethylene-1,3-dioxolane. The yield was 60 to 70%.
Fluorination of 2-methyl-2-methoxycarboxyl-4,5-cyclotrimethylene-1,3-dioxolane
[0090] The obtained 2-methyl-2-methoxycarboxyl-4,5-cyclotrimethylene-1,3-dioxolane was fluorinated in a fluorinated solvent, Fluorinert FC-75 (trade name) with F 2 /N 2 as described in Example 1. The reaction product was treated with potassium hydroxide to thereby produce perfluoro-2-methyl-2-potassium carboxylate-4,5-cyclotrimethylene-1,3-dioxolane. The potassium salt obtained was dried by heating at 60° C. under reduced pressure. The yield was 82%. The dried potassium salt was decomposed at 260° C. in the flow of argon gas. The crude product was distilled at 85° C. to produce perfluoro-4,5-cyclotrimethylene-2-methylene-1,3-dioxolane (yield: 79%).
[0091] Synthetic schemes according to Example 7 are schematically shown below.
EXAMPLE 8
Polymerization of perfluoro-4,5-cyclotrimethylene-2-methylene-1,3-dioxolane
[0092] 20 g of the perfluoro-4,5-cyclotrimethylene-2-methylene-1,3-dioxolane obtained by Example 5 and 150 mg of perfluorobenzoyl peroxide were charged in a glass tube. The polymerization was carried out as described in Example 2. A transparent amorphous polymer was obtained. The glass transition temperature of the polymer was found to be 150° C.
[0093] As described above, the polymers obtained are highly transparent and amorphous and also have a high glass transition temperature, and therefore, they are found as excellent materials that can be used for various applications of optical fibers, electrical materials, and the like. | A production method of fluorinated compounds, for producing a compound represented by formula (3) in a fluorine-based solution in a flow of fluorine gas after reaction of at least one type of compounds represented by formula (1) and at least one type of compounds represented by formula (2). Similarly, fluorinated compounds represented by formula (4) prepared by the fluorination of compounds obtained by the reaction of formula (1) and formula (2)′. The fluorinated polymers obtained by the polymerizations of formula (3) and (4) compounds are useful as an optical or electrical materials.
wherein R 1 , R 2 , R 3 ,R 4 , R ff 1 , R ff 2 , R ff 3 , R ff 4 , X, Y, Z, and n are defined in the specification respectively. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates, in general, to top-supported doors, and more particularly to resilient doors suitable for cold storage rooms.
BACKGROUND OF THE INVENTION
[0002] So-called horizontal sliding doors include at least one door panel that is suspended by a carriage that travels along an overhead track. The door panel may be manually or automatically moved from a blocking position to an unblocking position along the overhead track. Wider door openings are often spanned by having two bi-parting door panels. In some instances, the amount of overhead track required to extend beyond the door opening is reduced by having the door panel vertically divided into a number of coupled (e.g., over-lapped, hinged) vertically-separated leaves that take up less horizontal space when moved to the unblocking position.
[0003] Cold storage lockers are often accessed through a door opening closed by a sliding door. The panels for this purpose are typically transparent vinyl sheets, minimally insulated flexible panels or foam filled rigid panels. The transparent vinyl sheets are selected to reduce the likelihood of damage to the door. In particular, such doors are used in institutional (e.g., warehouse) setting wherein palletized cargo is moved in and out of a cold storage locker by forklift. Another advantage to these doors is that forklift operators can see what is on the other side of the door before opening the door. Although providing damage resistance, these types of panels have a very low insulation value and are too flexible to provide an effective air seal between the environments on either side of the opening. Because of the properties of the material, the transparent vinyl sheets may develop a warp that prevents a good seal. Air pressure differentials will cause leakage due to the lack of a compressive seal between the door panels and the doorframe. This will allow a significant amount of warm moist air to enter the cold storage locker and/or refrigerated air to be lost into an unrefrigerated space. Consequently, such door systems are less efficient to operate and can suffer from ice accumulation in the cold storage locker.
[0004] Rigid door panels are often used, especially in the United States, in order to reduce the operating costs of a cold storage locker. The rigid panel provides a consistent surface to seal to the doorframe. The thickness of the rigid door panel is selected to provide a specific amount of insulation. While these rigid door panels provide an effective closure, impact by a forklift can cause damage to the door system that would make them inoperative and limit access to the cold storage locker.
[0005] Attempts have been made to provide a damage resistant door panel for a sliding door system that also provides sufficient insulation. Resilient door panels have been suggested which have sufficient thickness to insulate like a rigid door panel, but yield to a degree when impacted by a forklift. While the panel itself achieves a degree of insulation, the insulation capability of the overall door system suffers from poor sealing between panels and poor sealing between a panel and the doorframe. Specifically, the stiffness of each door panel tends to be less than that of a rigid door panel, and thus presents less of a compressive contact to a doorframe gasket to achieve a seal. To achieve a seal with this type of panel different devices have been tried. Interlocking gaskets can be damaged as the door is pulled away from the casing. In addition they require rigid plates in the door panel for attachment which makes the panel heavier and less resilient. Others have used wall mounted guide tracks to pull the middle of the door back. This adds additional cost, makes installation more difficult and does not address sealing of the entire edge of the door; it only forces a seal at the top, bottom and middle. Because of the application it is difficult to add electrical wiring to the panel because it is flexible and could be torn open and damage or expose wiring. Condensation control on the panel is typically done using resistance wire but that will does not work because of the panel design. Others have tried using external heaters and blowers that are an inefficient means of controlling the condensation.
[0006] Consequently, a significant need exists for an improved door system that is suitable for institutional cold storage lockers by providing significant thermal insulation, efficient condensation control yet being resistant to damage from impacts.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention overcomes the above-noted and other deficiencies of the prior art by providing a resilient door panel for a sliding door system that achieves a good seal to a doorframe by attracting the door panel. The compressive seal is achieved without reliance upon a rigid back surface of the door panel, or upon the weight of the door panel. Therefore, materials and assembly methods may be selected for a desired resilience, insulation and economy of manufacture.
[0008] In one particular aspect of the invention, a resilient door panel is used in a closure system. A seal formed between a doorframe and the door panel is effectively achieved by attracting the door panel to the doorframe either pneumatically or magnetically. Eliminating the need for rigid components in the door panel enables the use of numerous manufacturing approaches, such as bagged foam sheets, bagged poured foam door panels, and even unbagged foam doors that self-skin. Thereby, the manufacturing steps are greatly reduced and thus the cost of each door panel.
[0009] In another aspect of the invention, an approach to keeping the door seals free of ice is provided that is particularly suitable to resilient door panels. In particular, since the resilient door panel readily flexes, it is desirable to eliminate electrical wiring in the door panel that may be damaged during impact. Thus, heating of a door panel periphery by electrical resistive heating is eliminated;
[0010] however, it is desirable to ensure that the seals between the doorframe/door panel, door panel/floor and door panel/door panel does not accumulate frost. Otherwise, the door system drive mechanism or the seal may be damaged in attempting to overcome a frozen seal. The door system may fail to open altogether if sufficiently stuck to stall the drive mechanism. Other problems associated with frost accumulation include achieving a poor seal with the resulting economic inefficiencies and safety and appearance issues related to accumulating ice and moisture.
[0011] In yet a further aspect of the invention, an automated door system includes a door position sensor that senses the door panel being in a closed position with a periphery of a door panel registered to a doorframe. A door positioning system responds to the door position sensor indicating that the door has been impacted by resetting the door panel to an open position, thereby mitigating possible damage to the door system.
[0012] Thus, in another aspect of the invention, a frost control system is incorporated into the closure system to warm the refrigerated air from the cold storage locker, which advantageously tends to contain less water vapor than air from the unrefrigerated side of the door. The warmed air is directed through an air passage to proximity of a periphery of the door panel and its seal to the doorframe. In particular versions of the invention, this air passage includes passing inside of the door panel.
[0013] These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
[0015] [0015]FIG. 1 is front exploded perspective view of a damage resistant door system for an institutional cold storage locker.
[0016] [0016]FIG. 2 is a diagrammatic view of a frost resistant sealing system of the door system of FIG. 1.
[0017] [0017]FIG. 3 is a top diagrammatic view of an astragal between the two door panels of the door system of FIGS. 1 - 2 .
[0018] [0018]FIG. 4 is a front view of a doorframe-mounted portion of a frost control system of the door system of FIG. 1.
[0019] [0019]FIG. 5 is side cross sectional view along line 5 - 5 of FIG. 1 exposing an air passage of the frost control system passing through both the doorframe-mounted portion and a door panel.
[0020] [0020]FIG. 6 is a cross sectional, detail view taken along line 6 - 6 of the air channel and gasket seal of the door system of FIG. 1.
[0021] [0021]FIG. 7 is an exploded perspective view of a resilient, laminated door pad with a cover removed for the door system of FIG. 1.
[0022] [0022]FIG. 8 is an exploded perspective view of the door panel of FIG. 1 including the resilient laminated door pad of FIG. 7.
[0023] [0023]FIG. 9 is a cross sectional view along line 9 - 9 of a magnet embedded portion of the door panel of FIG. 8.
[0024] [0024]FIG. 10 is a cross sectional view along line 10 - 10 of a bottom edge air passage of a sill of the door panel of FIG. 8.
[0025] [0025]FIG. 11 is an exploded view of the door mounted gasket assembly of the door system of FIG. 1.
[0026] [0026]FIG. 12 is a horizontal cross sectional view along line 12 - 12 of FIG. 1 illustrating a passive gasket system of the door system.
[0027] [0027]FIG. 12A is a horizontal cross sectional view along line 12 - 12 of FIG. 1 illustrating an alternative, active gasket system of the door system.
[0028] [0028]FIG. 12B is a horizontal cross sectional view along line 12 - 12 of FIG. 1 illustrating an alternative, loop gasket system of the door system.
[0029] [0029]FIG. 13 is a diagrammatic view of an alternative frost control system including recycled warmed air for the door system of FIG. 1.
[0030] [0030]FIG. 14 is a diagrammatic view of an alternative air-stiffened door panel for the door system of FIG. 1.
[0031] [0031]FIG. 15 is a horizontal cross sectional view of the door panel of FIG. 14.
[0032] [0032]FIG. 16 is a further alternative air stiffened door panel for the door system of FIG. 1.
[0033] [0033]FIG. 17 is a perspective, partially cutaway view of an alternative bagged, poured foam door panel for the door system of FIG. 1.
[0034] [0034]FIG. 18 is a horizontal cross sectional view of the bagged, poured foam door panel of FIG. 17.
[0035] [0035]FIG. 19 is front diagrammatic view of the door panel of FIG. 17 being filled with poured foam.
[0036] [0036]FIG. 20 is a perspective, partially cutaway view of a further alternative fixture for forming an unbagged, poured foam door panel for the door system of FIG. 1.
[0037] [0037]FIG. 21 is a front cross sectional view along line 21 - 21 of the fixture and foam attachment device of FIG. 19.
[0038] [0038]FIG. 22 is a perspective view of a completed self-skinning door panel formed in the fixture of FIG. 19.
[0039] FIGS. 23 A-F are top view diagrams of a damage resistant door system incorporating an auto-reset feature.
DETAILED DESCRIPTION OF THE INVENTION
[0040] Turning to the Drawings wherein like numbers denote like components throughout the several views, in FIGS. 1 - 3 , a closure system, depicted as a bi-parting horizontal sliding door system 10 , advantageously includes fully resilient door panels 12 , 14 for damage resistance that are affirmatively sealed to a doorframe 16 by an attraction sealing system, depicted as a magnetic sealing system 18 , to effectively separate a warm space 20 from a cold space 22 (e.g., a cold storage locker). As shown particularly in FIG. 1, the door panels 12 , 14 are supported by and power actuated by an overhead carriage 24 , as is generally understood by those skilled in the art.
[0041] With particular reference to FIG. 2, the sliding door system 10 advantageously includes a frost control system 26 for preventing accumulation of ice on a sealing gasket 28 on the doorframe 16 . Cold air from the cold space 22 passes through and is warmed by an air passage 30 that includes an air channel 32 in a periphery of each door panel 12 , 14 . In particular, the cold air is drawn through an intake manifold 34 , which is encompassed and warmed by an upstream electric heater 36 , into an air mover, depicted as a blower fan 38 driven by an electric motor 40 . The upstream heater 36 provides dry, warm air to the blower fan 38 , allowing the blower fan 38 to operate in an environment that promotes its reliability. Pressurized air from the blower fan 38 is then directed through an exhaust manifold 42 , which is advantageously encompassed by a downstream electric heater 44 that further warms the air to a temperature sufficient to keep the sealing gasket 28 frost free, although it will be appreciated that one heater may be sufficient in some applications or that the heating is performed in the air mover.
[0042] With particular reference to FIG. 3, an astragal contact 46 between the right door panel 12 and the left door panel 14 is depicted. In the nearly closed position as depicted, a concave, vertical recess 48 of the left door panel 14 receives a vertical rounded end 50 of the right door panel 12 . A vertical The recess 48 and rounded end 50 define a vertical astragal air channel 52 that is in communication with a horizontal air channel 54 of the right door panel 12 and with a horizontal air channel 56 of the left door panel 14 . Thereby, leading edges 58 , 60 respectively of panels 12 , 14 contact each other for a good sealing between the warm and cold spaces 20 , 22 while also directing warned air downward throughout the astragal contact 46 to prevent frost accumulation.
[0043] With particular reference to FIG. 4, the exhaust manifold 42 is shown separating into right and left outlet ports 62 , 64 for directing warmed air to a respective door panel 12 , 14 (not shown in FIG. 3). Also depicted is a down-and-in track 66 of the overhead carriage 24 that presents the door panels 12 , 14 into compressive contact with the outlet ports 62 , 64 and a horizontal gasket assembly 68 of the sealing gasket 28 , yet avoid frictional wear as the door panels 12 , 14 are positioned.
[0044] In FIG. 5, the right outlet port 62 is depicted as positioned to communicate with the horizontal air channel 54 in the right door panel 12 via back face air passage 70 . Also depicted in more detail is the overhead carriage 24 .
[0045] In FIG. 6, the horizontal air channel 54 in the door panel 12 is shown proximate to the horizontal gasket assembly 68 . In this illustrative version, the door panel 12 is compressed into the horizontal gasket assembly 68 without having to use magnetic attraction. Thus, the horizontal gasket assembly includes a resilient plug 72 between its over surface and a heated support structure 74 .
[0046] In FIG. 7, the resilient portions of the door panel 14 are shown. In particular, a composite pad 76 is formed from two flexible neoprene sheets 78 , 80 , selected for a high degree of resilience for impacts, which are glued respectively to each side of a more rigid polyethylene slab 82 , selected for holding the shape of the pad 76 and for receiving a drilled horizontal air channel 54 and routered vertical air channel (both not shown in FIG. 7) about its trailing edge 84 . Permanent magnets 82 are embedded in the back neoprene sheet 78 .
[0047] Alternatively, a composite pad (not shown) may be formed from a rigid material of polyurethane insulation, typically used in rigid door panels, in place of the polyethylene slab 82 . Flexibility is achieved by dividing the urethane insulation into a plurality of mosaic, tile-like pieces. The pieces are held in place between the neoprene sheets 78 , 80 . The size of the pieces may advantageously be chosen for the desired degree of flexibility. For example, the tile size may be reduced at lower portions more prone to impact. Moreover, for a given thickness, the urethane has a higher insulation value than polyethylene. Thus, if more flexibility is desired, the thickness of the panel may be reduced without sacrificing insulation. Alternatively, the same thickness of the panel may be maintained with a realized increase in economic efficiency.
[0048] It will be appreciated that a number of materials may be used depending upon the degree of insulation, flexibility, thickness, cost, chemical environment, etc. Additional examples include a silicone sheet, a bead board, cross linked polyethylene, etc.
[0049] In FIGS. 6 and 8, the assembled pad 74 is shown with a cover 84 of polyvinyl chloride (PVC) fabric that is glued over the pad 74 . The assembly is attached with adhesive and mechanical fasteners to a structural member 86 across the top of the pad 74 . Attachment members 88 spaced along the top of the structural member 86 are fastened to a roller assembly 90 , which rides on the track 66 of the overhead carriage 24 (shown in FIG. 4).
[0050] In FIG. 9, one permanent magnet 82 is shown embedded in an assembled panel 12 .
[0051] In FIGS. 8 and 10, a bottom sill 92 is shown wherein a bottom structural member 94 is affixed to the bottom of the pad 74 . Perforated supports 96 space the pad 74 above the bottom structural member 94 and defines the bottom portion of the air channel 32 in the door panel 12 .
[0052] In FIGS. 11 - 12 , the magnetic sealing system 18 of the gasket seal 28 is shown in greater detail. A frame casing 98 is mounted to a front face of a wall 100 that defines a door opening 102 . For instance, the casing 98 may comprise metal sheeting encasing a wood beam as is generally known. The wood may be replaced with another core material such as urethane to avoid problems associated with use of wood in a moist environment (e.g., swelling, bacteria growth, rotting). If plastics are used, the covering material may be adhered to the core material to minimize thermal distortion. This can be done by injecting the core material into a preformed cover or wrapping a cover of a preformed core and bonding it to the core. Advantageously, the casing 98 may comprise formed or extruded material (metal, plastic, fiber reinforced composites) as strength, stiffness or temperature conditions dictate.
[0053] An aluminum extruded guide 104 cradles two resistive electrical cables 106 , 108 and is held in place between a ferrous strip 110 and a front surface 112 of the casing 98 by fasteners 114 . A primary gasket 116 of PVC or other flexible reinforced fabric is bolted through a strip 117 to the front surface 112 and is wrapped over the ferrous strip 110 and a spacer block 118 , over which a secondary gasket 120 is placed and held in place by an angled bracket 122 . The secondary gasket 120 may alternatively be positioned outboard of the primary basket 116 as well as inboard at the door opening as depicted. Fasteners 124 pass through the bracket 122 , secondary gasket 120 , primary gasket 116 , spacer block 118 to attach to an inner surface 126 of the casing 98 . When the door panel 12 draws near its closed, blocking position, the magnets 82 draw the door panel 12 toward the ferrous strip 110
[0054] [0054]FIG. 12A depicts an active magnetic attraction system 128 that provides additional control features over the previously described passive magnetic attraction system 18 . A gasket seal 130 that incorporates the active magnetic attraction system 128 is similar to that described for FIG. 12 with an electromagnet 134 mounted to a ferrous or non-ferrous strip 110 . In the case of a non-ferrous strip, the door pad 12 tends to stay in place under the magnetic attraction between the permanent magnet 82 and the electromagnet 134 . When opening the door panel 12 , the electromagnet 134 may be advantageously polarized to the same magnetic pole as the adjacent face of the permanent magnet 82 , thereby repulsing the door panel 12 . The repulsion assists in overcoming any frost present and tends to hold the panel 12 away during movement to avoid frictional damage. The electromagnet 134 may assist in pulling the door close enough to the ferrous strip 110 that the permanent magnets 82 in the door will thereafter hold the door in place without the help of the electromagnet. When the door opens, the pole on the electromagnet 134 can be reversed to break the seal and make it easier for the door to open.
[0055] It will be appreciated that the door panel 12 may include a ferrous target (not shown) rather than a permanent magnet wherein the electromagnet 134 actively holds the door panel 12 closed and is deactivated when opening the door panel 12 .
[0056] [0056]FIG. 12B depicts a low-wear gasket system 18 a, similar to the magnetic sealing system 18 of FIG. 12 except that the main gasket is no longer under pressure from a magnet assembly thereby eliminating a source of friction and wear to the door panel 14 . Instead, the magnetic attraction feature has been provided separately as a rearwardly projecting, trailing edge magnetic flap 131 that acts as its own primary seal. A loop 133 of PVC fabric is attached along the full height of the trailing edge of the door panel 14 and is directed inwardly toward the wall 100 . A small permanent magnet 82 a, affixed to the inside of the loop 133 , is registered to be attracted to a ferrous plate 135 attached to a vertical, outward edge of the frame casing 98 . In addition to eliminating the frictional wear from the secondary gasket 120 , this trailing edge magnetic flap 133 may accommodate a door panel 14 with additional flexibility and curve. Moreover, the permanent magnet 82 a is advantageously small in that its amount of magnetic field strength need only be great enough to draw a rather light weight flap 133 into contact with the ferrous plate 135 rather than to draw the entire door panel 14 into contact.
[0057] Returning to FIG. 2, the operation of the door system 10 generally begins with the door panels 12 , 14 closed as depicted, with permanent magnets 82 drawing the door panel 12 into contact with the gasket seal 28 . A door controller 136 energizes resistive electrical cables 106 , 108 in the gasket seal 28 to assist in frost control. The door controller 136 also energizes the motor 40 to turn the blower fan 38 to draw cold, dry air from the cold space 22 into the air passage 30 . Specifically, in the intake manifold 34 , the cold air is partially warmed by the upstream electrical heater 36 to keep the blower fan 38 and motor 40 in an optimum temperature range. Also, the pressurized air is further warmed by the downstream electric heater 44 . The door controller 136 may closed-loop control the temperature of the warmed air with a temperature sensor 138 , such as depicted in the intake manifold 34 . It will be appreciated that one or more sensor may be used to optimize the temperature in various regions of the air passage 30 . The warmed air is passed through the outlet port 62 into the air channel 32 in the door panel 12 . The warmed air passes through the astragal passage air channel 52 with the panel 14 and around the periphery of the door panel 12 proximate to the gasket seal 28 and thereafter is vented into the warm space 20 . The door controller 136 may condition activation of the frost control system 26 on confirming that the door panel 12 is closed, as sensed by a switch 140 .
[0058] In response to user actuation of an opening device, depicted as a door pull rope switch 142 , the door controller 136 deactivates the frost control system 26 and may activate the electromagnet 134 (if present) (not shown in FIG. 2) to repulse the door panel 12 . The door controller 136 then actuates a door motor 144 , such as a two-speed, three phase electric brake motor, that is coupled to the door panel 12 . It will be appreciated that a single speed motor with a variable frequency drive may be used as another alternative. Once opened, the door controller 136 awaits until user actuation of the door pull rope switch 142 to close the door panel 12 . The door controller 136 may monitor a sensed pneumatic pressure on one or both leading edges 58 to reverse or stop the door motor 144 as a safety feature. The door controller 136 may also monitor stalling of the door motor 144 indicative of system failure or other blockage, such as by monitoring motor current “I” with a current sensor 146 . It will be appreciated that due to the flexible nature of the door panel 12 , monitoring of motor current may be sufficient without a pneumatic sensor on the leading edge.
[0059] In FIG. 13, an alternative door system 148 illustrates additional features that may be incorporated into a pressurized frost control system 150 . Recycling the pressurized air rather than venting the air into the warm space 20 may advantageously reduce the amount of electrical power required to keep the door panel 12 warm. Another advantage or use would be to air stiffen the door panel 12 by inflating air tubes 152 in the door panel 12 .
[0060] Air recycling is shown with a return passage 154 from the door panel 12 to an upstream intake 156 of the blower fan 38 . A check valve 158 may be included in the intake manifold 34 to prevent inadvertent porting of return air into the cold space 22 . In addition, a pressure relief check valve 160 may advantageously be included in the return passage 154 to prevent damage to the door panel 12 such as during an impact.
[0061] In FIGS. 14 - 15 , an air-stiffened door panel 162 is depicted wherein the warmest air is first directed around the periphery for gasket warming purposes and also allowed to pressurize vertical air tubes 164 In FIG. 16, an alternative air-stiffen door panel 166 includes a porous or quilted central portion 168 that is pressurized.
[0062] In FIGS. 17 - 19 , a bagged, poured foam door panel 170 is depicted as an alternative to glued foam laminate construction. A bag cover 172 includes a plurality of vertical dividers constructed of a material similar to the bag 174 that control the flow of uncured foam so that the resulting door panel 170 has the desired shape. Thereby, use of a large fixture may not required. Moreover, large shipping containers may be avoided by shipping an unfilled bag cover 172 with a supply of uncured foam (not shown) that is used on location. Features such as permanent magnets (not shown) may be affixed to the bag cover 172 .
[0063] In FIGS. 20 - 22 , an unbagged, poured foam door panel 176 that may have advantages in reducing cost of manufacturer by eliminating the bag cover. A fixture (not shown) positions hanger structures 178 and other door hardware 180 until injected foam 182 cures onto these elements, the hanger structures 178 may be of various forms that facilitate a large surface area attachment to the foam with horizontal protrusions to resist pull-out, for instance, a “tree root” like structure, perforated plate, or simple bar with cross pieces etc. A self-skinning flexible foam advantageously attaches to the hanger structures 178 and forms a wear resistant surface without the additional manufacturing step of attaching a cover.
[0064] FIGS. 23 A-F depict operation of an auto-reset feature of a damage resistant door system 200 that may advantageously be incorporated into applications that are automatically actuated. In FIG. 23A, the door system 200 is depicted in its normal, closed position with left pad 202 abutting right pad 204 , thereby closing a door opening 206 . The distal lower portions of the left and right pads 202 , 204 are each inwardly held by left and right restraining devices 208 , 210 against left and right doorframes 212 , 214 , respectively, forming a seal against corresponding left and right gaskets 216 , 218 .
[0065] In the illustrative embodiment, the restraining devices 208 , 210 are rollers but could be any device protruding upwards on the front side of the panels 202 , 204 . These restraining devices 208 , 210 may be attached to the floor or to the door casing. In the latter configuration, the restraining device may require that a bracket go under the door to hold the restraining device. It should be appreciated that the left and right restraining devices 208 , 210 may have application in manually opened door systems as well as automatically opened door systems, especially when significant air pressure differential exist at times across the door opening or when the door pads 202 , 204 are sufficiently flexible as to needing an urging at their lower portions to seal against the doorframe 212 , 214 . In some applications, the normal travel of the door panels 202 , 204 may maintain the respective restraining device 208 , 210 in contact, avoiding any damage when the leading edge of the door panels 202 , 204 encounters the restraining device 208 , 210 when closing. In other applications, the door panels 202 , 204 at their most open position are not in contact with the restraining devices 208 , 210 . Thus, guides (not shown) may inwardly direct the leading edge of the door panels 202 , 204 to counter any outward deflection of the lower portion of the door panel 202 , 204 .
[0066] Although the restraining devices 208 , 210 advantageously assists in sealing the flexible door panels 202 , 204 , mitigating damage from impacts is enhanced by having the restraining devices 208 , 210 sufficiently low as to allow an outwardly forced door panels to pop over the restraining device 208 , 210 .
[0067] Sufficient lateral travel in the overhead carriage (not shown in FIG. 23A) thus allows the door to be reinserted between the restraining devices 208 , 210 and doorframe 212 , 214 when cycled fully open and then closed.
[0068] In some applications it is advantageous to retain a normal operation wherein the door remains at all times in contact with the restraining device 208 , 210 , avoiding impacts to the leading edge, while also providing for the resetting after the door panel 202 , 204 is forced outward during an impact. Moreover, it is a further advantage for the door to begin to open when a forklift impacts the door panel 202 , 204 to thereby minimize the amount of deflection required for the vehicle to pass through.
[0069] To that end, a capability for sensing that the door panels 202 , 204 have achieved a fully closed position with an effective seal is provided by left and right sensors, depicted as left and right magnetic field transducers 220 , 222 (e.g., Hall effect transducers) that sense the proximity respectively of left and right magnets 216 , 218 in respective pads 202 , 204 . Signal lines 224 , 226 to each transducer 220 , 222 respectively communicate to a control system (not shown) that respond to the sensed position. It will be appreciated that sensing the magnets 216 , 218 takes advantage of magnets that also assist in sealing the door panel 202 , 204 to the doorframe 212 , 214 . However, other types of sensors may be used, such as mechanical limit switches, optical sensors, etc.
[0070] In FIG. 23B, an impact is illustrated at arrow 228 as coming inside the cold storage space, forcing the door pads 202 , 204 outward. The selection and placement of sensors 220 , 222 may advantageously detect impacts from both directions. For instance, an impact from either direction may tend to draw the lower, trailing edge of the door pad 202 , 204 upward and inward, which may detected by various proximity sensors. Alternatively, the impact from either direction may pull the lower, trailer edge of the door pad 202 , 204 completely out from the doorframe 212 , 214 and restraining device 208 , 210 , which may be detected by a limit switch. As yet a further alternative, multiple sensors on each side may be used to detect impact from either direction.
[0071] In FIG. 23C, the impact has caused each door pad 202 , 204 to ride over the respective restraining device 208 , 210 . Also, the door system 200 has responded to the sensed impact by beginning to auto-set by opening the door pads 202 , 204 .
[0072] In FIG. 23D, the door pads 202 , 204 have been drawn to a fully open position, wherein the leading edges are beyond the respective restraining devices 208 , 210 . The pads 202 , 204 are thereafter maintained in this position for a period of time or until sensed as having swung back toward the doorframe 212 , 214 under the influence of gravity, as depicted in FIG. 23E.
[0073] In FIG. 23E, the door system 200 has closed the pads 202 , 204 , completing the auto-reset back to the condition that existed prior to the impact. It will be appreciated that closing may be contingent upon a timer typically sufficient for any impacting vehicle to have left the door opening 206 . Alternatively or in addition, automatic closing during auto-reset may be contingent upon sensing an unimpeded door opening, such as by an unblocked optical beam across the door opening 206 .
[0074] While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art.
[0075] For example, while air warming of the entire periphery of a door panel may be advantageous, in some applications only one, two or three edges may be warmed. For instance, a upper edge and a trailing edge may rely solely on electrical warming in the doorframe as sufficient, whereas the leading edge and bottom edge are internally warmed by air.
[0076] While a magnetic attraction is depicted and described for advantageously compressively sealing the door panel to the doorframe, it will be appreciated that other approaches may be employed to attract the door panel to the doorframe. For example, pneumatic suction may created about the doorframe that is presented to pull in the periphery of the door panel.
[0077] While air warming of the door panel has been advantageously depicted, it should be appreciated that other warming techniques may be employed that do not rely upon electrical wiring in the door panel. For example, inductive targets may be embedded or affixed to the periphery of a door panel. A radiated electromagnetic signal from the doorframe may then be used to inductively couple power into the inductive targets to cause resistive heating in the door panel.
[0078] Air stiffening of the door panel 12 may also be provided separate from a frost control system. For example, separate air tubes dedicated for use as air stiffening bladders may be pressurized and left pressurized rather than recycling the air for heating.
[0079] Synergy exists between using these aspects of the invention together in a door system for a cold storage locker; however, it will be appreciated that aspects of the present invention may be used separate and apart from the other features.
[0080] For instance, separating environments may be very desirable for soundproofing or preventing airborne particulates from passing through the doorway. Another example is coolers that are maintained above freezing. Consequently, the effective sealing of the door panel by attraction may be employed without the need for a frost control system. As a further example, the configuration of how the door panels is positioned may provide sufficient affirmative urging into sealing contact with the doorframe that an attraction capability is not required, although the elimination of frost at the sealing contact may still be desired.
[0081] It will be appreciated that aspects of the present invention have application to door systems that fold individual panels in an according fashion in order to require less lateral travel when opened. Furthermore, aspects of the present invention have application to door systems that are not supported from an overhead track.
[0082] In the illustrative embodiment of FIGS. 23 A-F, the door system 200 includes both restraining devices 208 , 210 and door position sensors 220 , 222 that may be used in an auto-resetting feature. Although a door closed and sealed sensing capability is disclosed in combination with a physical restraining capability, it will be appreciated that door-positioning sensing has applications without the physical restraining capability. For instance, a failure indication may be given to operators when a situation is detected where the door should have achieved full travel yet a seal is not achieved. Furthermore, automatic opening of the door upon impact may advantageously reduce damage to the door system even if restraining devices are not present. | A door system for a cold storage locker has increased resistance to damage when by including resilient door panels that flex when hit by a forklift. A high degree of insulation is achieved by the choice and thickness of the resilient foams therein. Also, the resilient door panels are magnetically attracted to a gasket seal on a doorframe to provide an affirmative seal. Active magnetic control may enhance the attraction or repulsion of the door panel. Frost control is realized by warming air from the cold storage locker and passing it through air channels in the door panel proximate to the gasket seal and down an astragal interface between door panels. Door panels of laminate, bagged poured foam formation, and self-skinning foam formation give further reduced cost of manufacture and shipping. | 4 |
CROSS REFERENCE TO PRIOR APPLICATION
This application is a continuation-in-part of our pending application Ser. No. 764,170 filed Jan. 31, 1977, and now abandoned and hereby incorporates by reference the subject matter of such prior application.
BACKGROUND OF THE INVENTION
This invention relates to apparatus for liquid portioning and/or liquid transferring and specifically to a multichannel pipette and to replaceable tip containers for use with such a multichannel pipette.
In many laboratory determinations, apparatus is needed to transfer small precisely measured amounts of liquid from one tube into another. The system must be simple, rapid, economical, and precise. Transfer of small liquid quantities from one container into another has increased in laboratory applications particularly in connection with many liquid dosages and diluting series utilized in Bacteriology, Immunohaematology, Mycology, Mycoplasma, Parasitology, Rickettsia, Serology, Virology and V.D. Serology.
Liquid transfer may of course be performed in single tube pipettes either of the simple glass tube type or of the adjustable automatic type. When it is desirable to transfer given amounts of liquid from and to a multiplicity of sample containers it is far more economical to utilize apparatus which can transfer several samples simultaneously.
There are prior art systems which permit the transfer of more than one sample. In the system related to the registered trademark "Cooke Microtiter," a plate is used that has 8×12 pits, and the titration from one pit into another is performed by means of one or several microdiluters. These single microdiluters are either held in the hand, or several of them are held in a device which is handheld. Alternatively, they may be mounted in an automatic device placed in a machine. The mixing of the liquid in a pit is performed by rotating the microdiluter back and forth. The microdiluter transfers liquid so that the sample or reagent, due to capillary force, adheres to the calibrated tip portion of the microdiluter. Most commonly, in this system, volumes of 25 and 50 ul are used. The "Cooke Microtiter" involves several drawbacks:
The microdiluters of the system cannot be precisely calibrated, because the filling of the tip portion takes place by capillary force and the tip portion may not empty completely because of dirt, scratches in the glass or other mechanical problem in the tip portion of the device. The residue remaining in the microdiluters can result in contamination of other samples. Because of this, careful cleaning of the microdiluters is necessary after each use. This is expensive and can lead to errors if the cleaning substance is not thoroughly removed.
It is also difficult to vary the volume of this device since there are eight to twelve different volumes of microdiluters and the correct volume must be on hand for each application. This can be both cumbersome and expensive.
Another system on the market is a multichannel pipette sold under the trademark, "Finnpipette." Such a device is disclosed in U.S. Pat. No. 3,855,868. This device utilizes replaceable tip containers. To avoid the problem of contamination and also to avoid the necessity of an expensive and time consuming washing or cleaning after each use.
This device is adjustable over a wide range of volumes by a micrometer adjustment which can provide the necessary precision. It can also be conveniently held and operated in one hand.
Prior art tip container elements were formed in a structure in which several tip containers were connected by a rigid support or connection plate. A tip container element with such a rigid construction can be fitted to the tip cones of only one configuration of a multichannel pipette. Since a multichannel pipette may be constructed with different numbers and arrangements of tip cones depending upon the desired end use, flexibility is needed in the configuration of arrays of tip containers. The present invention provides this needed flexibility.
The present invention improves the above described prior art devices in several important ways. First, it provides an improved arrangement of replaceable tip containers which makes such tip containers easier to use with various multichannel pipette configurations. Second, it provides interchangeable precalibrated handles which can be attached to the body portion of a multichannel pipette. The use of such precalibrated handles avoids the necessity for the accurate setting of the micrometer adjustment of the prior art "Finnpipette" device and permits less skilled laboratory personnel to achieve accurate results quickly and easily.
SUMMARY OF THE INVENTION
A multichannel pipette has a body portion which includes a body housing having first and second opposed ends. A plurality of tip containers for holding liquid communicate with the first end of the body housing. A plurality of cylinders having first and second ends are disposed within the housing with the first end of each of the cylinders communicating with one of the tip containers. A plurality of pistons have first and second ends and each of the second ends of the pistons extend into and are movable within one of the cylinders. A plurality of O rings are included. One of these O rings is disposed within each of the cylinders surrounding and in contact with each of the pistons. Spring bias means are provided to bias the O ring against the second end of the cylinder. A movable member is disposed within the housing and is connected to the first end of each of the piston rods.
A plurality of interchangeable handles are provided. Each handle is preadjusted to dispense a predetermined volume of liquid from the tip containers. Each such handle includes a housing which has first and second opposed ends. A rod is disposed within the housing and has a first end which extends through the first end of the housing. A push button is attached to the first end of the rod. Second spring bias means are provided to bias the rod so that the push button extends a predetermined maximum distance from the housing.
First connecting means are provided to detachably connect the handle housing to the body housing. Second connecting means are provided to detachably connect the second end of the rod to the movable member so that the movable member and the pistons are depressed in response to the depression of the push button to dispense a predetermined quantity of liquid from the tip containers.
An additional feature of the invention is a tip container element which is detachably connectable to the tip cone elements of a multichannel pipette. The tip container element includes a plurality of truncated conical tip containers, which are connected together in a linear configuration. Each of these tip containers includes a base portion which is detachably connectable to one of the tip cone elements of the multichannel pipette. Connecting means are disposed between the base portions of the adjacent tip containers which make up the tip container element. These connecting means include at least one flexible strip-like member having a length greater than the distance between the adjacent cone tip elements of the multichannel pipette.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a multichannel pipette having the interchangeable handle of this invention.
FIG. 2 is a partially cut away frontal view of the multichannel pipette, showing one embodiment of the tip container element of this invention.
FIG. 3 is a perspective view of a second embodiment of the tip container element.
FIG. 4 is a perspective view of a third embodiment of the tip container element.
DETAILED DESCRIPTION
FIG. 1 shows a multichannel pipette. The body portion 1 is provided with tip cone elements 2. Tip containers 3 are detachably connected to the tip cone elements. The handle part 4 includes, as visible in FIG. 1, a button 5, a button stem 6, and a secondary rest 7. The button 5 is pressed against the secondary rest 7, as the tip containers 3 of the multichannel pipette are submerged to the depth of about 0.5 to 1.0 cm in a liquid to be pipetted. Then, when the button 5 is allowed to rise to the upper position, due to the bias force of a first spring, the pistons suck a certain volume of the liquid from the pits 9 of the pit plate 8 into each tip container 3. The tip containers 3 are then emptied into the appropriate place, such as the next row of pits in the pit plate by pressing button 5 against the secondary rest 7 and continuing to press thereby depressing the button 5 some distance more against the secondary rest 7, which is biased upwardly by a second spring. After the tip containers have been emptied, the spring force restores the button 5 to its upper position.
FIG. 2 shows a 4-channel pipette. The handle part includes a housing 10, a calibration nut 11, with a space for a key 12 therein, a secondary rest 13, a button stem 14, a button 15, a secondary spring 16, which rests against a rest 17 for the secondary spring, placed in the housing 10. Secondary spring biases secondary rest 13 into its upper position to define stroke length "a." By turning the calibration nut 11 clockwise or anti-clockwise, it is possible to adjust the stroke length a of the button stem 14 so as to correspond a certain predetermined volume. The housing 10 of the handle part is by means of a thread fastened to the body portion 19. The body portion 19 includes a support disk 21 for the pistons 20, to which disk the activating rod 22 of the handle is fastened. The activating rod 22 is forced to the upper position by the bias force of a primary spring 23. The bottom plate 24 of the pistons 20 is fastened to the support disk 21. Support springs 25 force the pistons 20 against the support disk 21. The pistons 20 can move somewhat in the lateral direction. The force of the support springs 25 of the pistons 20 is dimensioned so that it is higher than the friction force created by the corresponding O ring 26 which surrounds each piston 20 and seals the piston in cylinder 28. The pistons 20 move in cylinder spaces 27 of their own. The cylinder space 27 is surrounded by a cylinder housing 28, which connects to and communicates with the tip cone 29. The O ring 26 is supported against the end 30 of the cylinder housing 28 by an O ring support 31 and is biased in place by a support spring 32. The force of the support spring 32 is higher than the frictional force caused by the O ring 26 of the piston 20. The cylinder housings 28 and the tip cones 29 constituting their extensions are fastened to a support disk 33, which is, on the other hand, fastened to the body portion 19.
The bases of the conical tip containers 34 are detachably connected over tip cone elements 29 to form an airtight seal with such elements. In accord with the present invention, the bases of the tip containers 34 are linked together in a linear configuration by small flexible connecting members or isthmuses 35 to form a tip container element 34(a). The connecting members are preferably longer than the distance between adjacent tip cone elements 29. This will cause the connecting members 35 to bow slightly as shown in FIG. 2 when the tip containers are connected to the tip cone elements 29.
When the individual tip containers 34 have their bases connected together by connecting member 35 they form elongated tip container elements 34(a) which nest inside of each other for easy packing and shipping. Projecting members 36 may be provided on the conical outer surface of each tip container. The presence of projecting members 36 prevents an excessively tight packing of the tip container elements within each other during shipping. Tip container elements such as those of FIG. 2, including connecting members 35 and projections 36 can be manufactured by injection molding from any flexible plastic material. Many such materials are known to those skilled in this art.
A user may cut or tear the tip container element 34(a) through one of the connecting members 35 at any desired point to detach any desired number of tip containers to fit a given configuration of tip cones on a multichannel pipette. Since the connecting members 35 are preferably made somewhat longer than necessary, a tip container element including a given number of tip containers can be used with pipettes having differing distances between their cone tips 29. Since the plastic material used for the tip container elements is flexible, the connecting element can be made to bow more or less depending on the distance between the tip cone elements.
A second more elaborate tip container element 13(a) is shown in FIG. 3. This element is configured to fit a multiple channel pipette having four tip cones. In this embodiment, two parallel flexible connecting members 15(a) are provided. A plurality of cross members 12(a) extend between the connecting members 15a. The individual tip containers 14(a) extend downwardly from the center of each cross member 12(a).
As in the embodiment of FIG. 2, the configuration shown in FIG. 3 may be made in any desired length by injection molding of a flexible plastic material. Again, the length of the connecting members 15(a) between the cross members 12(a) is made longer than necessary so that connecting members 15(a) bow out as much as necessary when attached to a configuration of tip cones. The connecting members 15(a) can again be cut or torn to provide a tip container element of the desired length.
The portions of the cross members 12(a) which extend outwardly from the tip containers together with the connecting members 15(a) define handle extensions. These handle extensions permit the user of the pipette to mount and dismount the tip container element 13(a) without the need to touch any of the tip containers 14(a). This is advantageous both to prevent contamination of the liquid to be pipetted by contact with tip containers which have been touched or to prevent contamination of the user's hands by contact with potentially dangerous substances which have been pipetted.
A third embodiment of the tip container element of this invention is shown in FIG. 4. This embodiment 16(a) includes continuous parallel connecting members 19(a) which extend along the sides of the element and cross members 20(a) extending between the connecting members 19(a). The cross members 20(a) differ in configuration from those employed in the embodiment of FIG. 3. The connecting members 20(a) include two relatively narrow strips 22(a) at their points of connection with the parallel connecting members 19(a) and an enlarged central portion 24(a) disposed about the point of connection with each of the tip container elements 18(a). The central portion 24(a) is preferably a four sided planar surface such as a square or rectangle with the opening 21(a) to the tip container approximately at its center. As a result of the configuration of the cross members 20(a) apertures 26(a) in the approximate shape of the Roman numeral I are defined through the planar surface 17(a) of the tip container element 16(a) between each adjacent tip container element 18(a).
As in the prior embodiments, the device of FIG. 3 is preferably injection molded of a suitable flexible plastic material. Because of the apertures, 26(a), the connecting members 19(a) are again free to flex or bend when attached to an arrangement of tip cones. Although the element 16(a) is configured for four tip containers it is to be understood that this element can be made in any reasonable desired length and can be torn or cut through apertures 26(a) to obtain an element of the desired length.
The extending portions, such as connecting members 19(a) of the embodiment 16(a) of FIG. 4 form handle extensions by which the device can be mounted on or removed from a multichannel pipette. The advantages of this feature were discussed above with reference to the embodiment of FIG. 3.
As in the embodiment shown in FIG. 2, the tip container elements of FIG. 3 and FIG. 4 may be nested for economical shipping. If desired, projections such as 36 in FIG. 2 may be added to the sides of the individual tip container elements in these embodiments to prevent too tight a packing of these elements. | A multichannel pipette is disclosed having an improved arrangement of replaceable tip containers in which the individual tip containers are connected together by flexible connecting members which are deformable to permit connection of the tip containers to differing configurations of tip cones. | 1 |
This application is a continuation of Ser. No. 09/293,010, filed on Apr. 16, 1999, now U.S. Pat. No. 6,176,042.
BACKGROUND OF THE INVENTION
The invention relates to gates and in particular unlocking of gates.
Gates are useful to inhibit undesired access through the gate while permitting relatively easy access if desired. Child safety gates are useful to help prevent injuries to children by inhibiting access through the gate by a child while permitting easy access through the gate by an adult. These gates can be mounted, e.g., in doorways, in hallways, between a wall and a stairway railing, or between two stairway railings (such as on a deck). With the gate in place, children are inhibited from accessing areas that are undesirable for the child to access. For example, it may be desirable to inhibit a child from accessing a kitchen, where toxic cleaners may be stored, or a stairway that the child may fall down. Safety gates can also inhibit children from gaining access to a pet or vice versa. A door of the gate can permit access if the door is moved to provide a passageway through the gate.
SUMMARY OF THE INVENTION
The invention provides a mechanism to guard against children undesirably opening a gate and also provides hands-free unlocking and opening of a gate. Among other uses the invention is highly effective in providing an obstruction to help prevent children or animals from accessing an area that it is undesirable for the child or animal to access. For example the invention can be used to block a doorway, hallway or other passageway.
In general, in one aspect, the invention provides an apparatus including a pair of frame members adapted for mounting to opposing surfaces of a passageway. A door is mounted to at least one of the frame members for movement between a closed position, in which the door and frame members substantially traverse the passageway, and an open position, in which a portion of the passageway is free of the door and frame members, the portion being large enough to permit passage of an adult therethrough. A lock is coupled to at least one of the frame members and adapted to retain the door in the closed position, the lock including an actuator adapted to release the lock to permit movement of the door from the closed position toward the open position upon application to the actuator of a force of at least a predetermined weight of a child.
Implementations of this aspect of the invention may include one or more of the following features. The actuator is disposed near a bottom portion of a frame member when the pair of frame members are mounted to the opposing surfaces. The predetermined weight is approximately 40 pounds. The lock is adapted to couple a frame member to the door near both a top of the door and a bottom of the door.
The actuator is adapted to move a recess camming surface, defining a portion of a recess, relative to and against a detent camming surface, of a detent that is biased into the recess when the door is in the closed position and the lock is in a locked position, to substantially remove the detent from the recess. The door is pivotally mounted to the frame about a pivot axis and the detent is a pin that is biased radially outward from the pivot axis. A substantially U-shaped frame includes the frame members and a cross member, the frame members being first and second arms forming sides of the U and the cross member connecting the arms and forming a bottom of the U, the door being pivotally attached to the first arm, and the actuator includes a bracket slidably carried by the second arm and including the recess camming surface. The door includes another pin, and the actuator includes a foot pedal, coupled to the bracket and movably mounted to the frame, including a foot pedal camming surface that provides a wall of a foot pedal recess and that moves relative to and against a pin camming surface, of the another pin that is biased radially outward from the pivot axis and into the foot pedal recess when the door is in the closed position and the lock is in the locked position, to substantially remove the another pin from the foot pedal recess when the foot pedal moves relative to the frame. The arms extend away from the cross member and away from each other.
In general, in another aspect, the invention provides a safety gate for use in a doorway, hall, or the like. The safety gate includes a substantially U-shaped frame having first and second arms connected by a cross member, the frame providing a passageway between the arms above the cross member. A bracket is movably coupled to the second arm and provides a bracket recess, a part of the bracket recess being provided by a bracket camming surface. A foot pedal is coupled to the bracket and movably coupled to the frame near the bottom end of the second arm. A spring is coupled to the foot pedal and requires a predetermined force to change a length of the spring. A door is pivotally mounted to the first arm along a pivot axis and includes a pin biased away from the pivot axis and configured to be received by the bracket recess, the door substantially preventing an infant from passing through the passageway when the pin is received by the bracket recess. When the foot pedal is moved toward a bottom of the frame in a gate-opening direction, the bracket camming surface bears against the pin to move the pin substantially out of the bracket recess.
Implementations of this aspect of the invention may include one or more of the following features. The predetermined force is about a weight of a three-year-old child. The passageway extends from a first side of the frame to a second side of the frame, and a portion of the foot pedal is disposed on the first side of the frame and another portion of the foot pedal is disposed on the second side of the frame. The first and second arms are adapted to engage opposing surfaces and extend from the cross member and away from each other such that when the arms are coupled to the surfaces such that the arms extend substantially perpendicular to the cross member, a force of less than about 40 pounds applied to the gate is insufficient to slide either arm relative to a respective one of the surfaces.
The bracket and the foot pedal are slidably carried by the second arm. The pin is a first pin, the foot pedal provides a foot pedal recess, partially provided by a foot pedal camming surface, the door includes a second pin biased away from the pivot axis and configured to be received by the foot pedal recess, and when the foot pedal slides relative to the frame in the gate-opening direction, the foot pedal camming surface bears against the second pin to move the second pin substantially out of the foot pedal recess.
In general, in another aspect, the invention provides an apparatus for use with a door movably mounted to a frame member between an open position and a closed position. The apparatus is adapted to inhibit the door from moving from the closed position toward the open position while in a locked position and to change to an unlocked position to permit the door to move from the closed position toward an open position if a force of at least a predetermined weight of a child is applied to the apparatus.
Implementations of this aspect of the invention may include one or more of the following features.
The door includes a door member having a door member camming surface and the apparatus includes an apparatus camming surface. The apparatus is further adapted to move the apparatus camming surface relative to the door when the force is applied to the apparatus and to remain substantially fixed relative to the door otherwise. The apparatus camming surface is configured and disposed to cause one of the camming surfaces, biased into a recess provided at least partially by the other camming surface, to be substantially removed from the recess. A portion of the apparatus is adapted to be slidably carried by the frame. The apparatus includes a bracket, slidably coupled to the frame, and an actuator to which the force is applied, the bracket including the apparatus camming surface. The recess is a first recess, the member is a first member, and the member camming surface is a first member camming surface, and the actuator includes an actuator camming surface configured and disposed to cause one of the actuator camming surface and a second member camming surface of a second member of the door, biased into a second recess provided at least partially by the other one of the actuator camming surface and the second member camming surface, to be substantially removed from the second recess when the force is applied to the apparatus. The apparatus comprises a foot pedal to which the force is applied.
Various aspects of the invention may provide one or more of the following advantages. A gate can be unlocked in a hands-free manner. A gate can also be unlocked and opened in a hands-free manner. Accidental opening of a gate can be guarded against. Undesired opening of a gate by a child or an animal such as a pet can also be guarded against.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an assembled safety gate, in a closed position, according to the invention.
FIG. 2 is an exploded perspective view of some of the components of the safety gate shown in FIG. 1 .
FIG. 3 is a cross-sectional view of the safety gate shown in FIG. 1 taken along line 3 — 3 shown in FIG. 1 .
FIG. 4 is a top perspective view of a foot pedal support shown in FIG. 2 .
FIG. 5 is a bottom perspective view of a foot pedal shown in FIGS. 1 and 2.
FIG. 6 is a perspective view of a bracket shown in FIGS. 1 and 2.
FIG. 7 is an enlarged portion of the cross-sectional view of the safety gate shown in FIG. 3 as indicated by line 7 — 7 , with the bracket shown in FIG. 6 in a locked position.
FIG. 8 is view similar to that shown in FIG. 7 but with the bracket shown in FIG. 6 in an unlocked position.
FIG. 9 is a perspective view of a wrench for use with the gate shown in FIG. 1 .
DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1, a gate 10 includes a frame 12 , a door 14 , a foot pedal 16 , and a bracket 18 . The gate 10 is adapted to be mounted between opposing surfaces 11 , 13 , 15 , and 17 , e.g., opposing sides of a doorway, walls of a hallway, or railings of a stairwell. With door 14 in a closed position 19 (as shown), frame 12 and door 14 are sized to substantially block the passageway in which gate 10 is disposed. When disposed in the passageway, gate 10 provides spaces between bars of the frame 12 and door 14 , and between frame 12 and the surfaces between which gate 10 is disposed, that are too small for children to fit through. Door 14 is pivotally mounted to frame 12 by an upper hinge 20 and a lower hinge 70 along a pivot axis 74 . Thus, door 14 can be pivoted from closed position 19 , shown in solid lines, to open positions such as open positions 22 and 24 indicated in simplified form with dashed lines. Positions 22 and 24 are not necessarily fully-open position. Door 14 can be pivoted from the closed position 19 in a direction 26 toward open position 22 and in a direction 28 from open position 22 toward closed position 19 . Similarly, door 14 can be pivoted in a direction 30 from a closed position 19 toward open position 24 and in a direction 32 from open position 24 toward closed position 19 . Foot pedal 16 and bracket 18 provide a locking and unlocking mechanism as described below.
As shown in FIG. 2 (that shows some but not all components of gate 10 ), gate 10 includes components in addition to frame 12 , door 14 , foot pedal 16 , and bracket 18 . Gate 10 also includes a linkage 34 , a bias spring 36 , a mounting assembly 38 , a pad 40 , a foot pedal support 42 , and a frame support 44 . Door 14 includes a barrier 46 , an upper assembly 48 and a lower assembly 50 .
Frame 12 is substantially U-shaped with two hollow D-shaped arms 52 and 54 connected at their respective bottoms by a cross member 56 . Arms 52 and 54 are also connected to cross member 56 through two extensions 58 and 60 and two bars 62 and 64 , respectively. Arms 52 and 54 and bars 62 and 64 extend away from cross member 56 , and slightly outward, away from each other, in directions 57 and 59 . Angles 61 and 63 between arms 52 and 54 and cross member 56 are slightly greater than 90°. Arms 52 and 54 are angled outwardly to provide a spring force such that a predetermined force is needed to move arms 52 and 54 inward to extend perpendicularly from cross member 56 . The predetermined force is selected to secure gate 10 between surfaces 11 and 13 and to inhibit children from overcoming the friction produced between gate 10 and surfaces 11 and 13 . Bars 62 and 64 are shaped and disposed to provide gate 10 with an appropriate width for substantially filling a passageway having a width between about 29 inches and about 34 inches. For example, bars 62 and 64 can provide a width of about 29 inches for frame 12 . The top of arm 52 is adapted to receive hinge 20 (FIG. 1) for pivotal connection to door 14 at an upper pivot point 66 of barrier 46 . Cross member 56 provides a hole 68 for receiving hinge 70 (FIG. 1) for pivotal coupling to door 14 at a lower pivot point 72 of barrier 46 such that door 14 can be pivotally coupled to frame 12 along pivot axis 74 (FIG. 1 ). Arm 54 is shaped to receive spring 36 and linkage 34 in an opening 76 that extends along the length of arm 54 . Upper slots 78 and 79 (only slot 78 shown) in arm 54 are sized to receive a rivet 80 and lower slots 82 and 83 (only slot 82 shown) are sized to receive a rivet 84 . Holes 86 and 88 (only hole 86 is shown) are sized to receive pins 90 and 92 , respectively. Pins 90 and 92 can extend into, but not all the way through, opening 76 of arm 54 .
Referring to FIGS. 2 and 3, spring 36 and linkage 34 are received in opening 76 of arm 54 , with spring 36 resting on pins 90 and 92 (indicated by dashed lines in FIG. 3 ). A lower portion 94 of linkage 34 is received by an interior 96 of spring 36 . A ledge 97 of linkage 34 rests on top of spring 36 . Spring 36 is configured such that with linkage 34 resting on top of spring 36 and attached to foot pedal 16 and foot pedal support 34 , a predetermined force is required to be exerted downwardly on linkage 34 as indicated by arrow 100 to compress spring 36 . This predetermined force is preferably greater than a typical weight of a three year old child, e.g., approximately 40 pounds.
Referring also to FIG. 4, linkage 34 is connected to foot pedal support 42 by rivet 84 . Support 42 provides holes 102 and 104 for receiving rivet 84 . Support 42 is configured to fit over a flat side 106 (FIG. 2) of D-shaped arm 54 , with arm 54 being received by a recess 108 of support 42 .
As shown in FIGS. 2 and 5, foot pedal 16 is configured to fit over a rounded side 110 of D-shaped arm 54 and to couple to pedal support 42 (FIG. 4 ). Pedal 16 is adapted to receive support 42 in a recess 112 and to snap on to support 42 . A U-shaped opening 114 in the top of the pedal 16 is shaped to slidably receive curved side 110 of arm 54 . On the outside of a closed end 116 of pedal 16 , a recess 118 is provided by several walls of pedal 16 . One of these walls is an angled wall 120 that provides a camming surface 121 , connected to a flat surface 123 , for engaging and interacting with a camming surface 168 of a pin 122 of lower assembly 50 (FIG. 2 ).
As shown in FIGS. 2 and 3, lower assembly 50 includes pin 122 , a cap 124 , and a spring 126 . Pin 122 as shown has a cylindrical shape, but other types of shapes, such as rectangular, are acceptable. Cap 124 is adapted to receive spring 126 and pin 122 and to be received by a hollow end 128 of barrier 46 . When gate 10 is assembled, pin 122 is biased by spring 126 to be received by recess 118 (FIGS. 3 and 5) of pedal 16 . Assembly 50 is similar to assembly 48 which will be described in more detail below.
Referring also to FIG. 6, a hole 129 in linkage 34 receives rivet 80 that couples linkage 34 through slots 78 and 79 in arm 54 to bracket 18 . Bracket 18 receives rivet 80 in two holes 132 and 134 (only hole 132 shown in FIG. 6 ). The bracket 18 provides a U-shaped recess 130 adapted to fit over curved side 110 of arm 54 . On the outside of a rounded end 136 , bracket 18 provides a recess 138 . Recess 138 is provided by several walls, including a wall 140 that provides an angled camming surface 141 and is connected to a flat surface 143 . Recess 138 is shaped such that when bracket 18 is received by rounded side 110 of arm 54 , bracket 18 can slide along the length of arm 54 .
Bracket 18 is guided for sliding along the length of arm 54 by arm 54 and rivets 84 and 80 received by slots 82 and 83 , and 78 and 79 , respectively. Slots 82 , 83 and 78 , 79 limit the range of motion of rivets 84 and 80 , and therefore limit the range of motion of linkage 34 relative to arm 54 . This in turn limits the range of motion of pedal 16 and bracket 18 relative to frame 12 and door 14 .
Referring to FIGS. 2, 6 and 7 , door 14 includes barrier 46 and upper and lower assemblies 48 and 50 .
Barrier 46 is made of, e.g., plastic and includes two hollow cross members 220 and 222 connected (e.g., sonically welded) to several bars 224 . Bars 224 are separated by distances too small for infants of crawling age or older (e.g., older than 4 months) to fit through.
Upper assembly 48 includes a pin 142 adapted to be received by recess 138 of bracket 18 , a cap 144 adapted to be received by barrier 46 , and a spring 146 . Like pin 122 , pin 142 as shown has a cylindrical shape, but other types of shapes, such as rectangular, are acceptable. Pin 142 has an end camming surface 148 configured to contact and slide against a wall 150 , camming surface 141 of wall 140 , and a flat surface 143 , of bracket 18 . Cap 144 fits inside an opening 152 (FIG. 2) of barrier 46 and has an end portion 154 that butts up against the end of top cross member 220 of barrier 46 . Pin 142 slidably fits within a hole 158 in cap 144 . A flared region 160 of pin 142 provides a recess 162 for receiving an end of spring 146 . The other end of spring 146 fits over a post 164 of cap 144 . Spring 146 biases pin 142 in a direction away from pivot access 74 (FIG. 1) and away from barrier 46 and toward bracket 18 in a direction transverse to pivot access 74 as indicated by an arrow 166 (see also FIG. 1 ). With door 14 in closed position 19 (FIG. 1) as shown, spring 146 biases pin 142 into recess 138 .
Referring to FIGS. 2, 3 , and 5 , lower assembly 50 is configured similarly to upper assembly 48 , with spring 126 and pin 122 received by cap 124 , and pin 122 biased toward foot pedal 16 and into recess 118 . Pin 122 , similar to pin 142 , has a surface 168 adapted to be a camming surface to engage, interact with, and slide against a bottom surface 170 and surfaces 121 and 123 of pedal 16 .
Referring to FIGS. 2 and 7, assembly 38 includes a cap 172 , a nut 174 , a knob 176 , a rod 178 , an end piece 180 , and a pad 182 . Cap 172 fits inside an opening 184 of extension 60 of frame 12 and an end 186 of cap 172 butts up against an end of extension 60 . Cap 172 includes a sleeve 188 with a finger 190 having a tab 192 at its end. An inner diameter 194 of sleeve 188 is sized to accommodate an outer diameter 195 of rod 178 . Tab 192 is disposed to interfere with rod 178 and finger 190 is adapted to flex to allow tab 192 to be moved to a position such that tab 192 will not interfere with rod 178 . Rod 178 has a threaded body 196 extending at least about three inches and over substantially the entire length of rod 178 except for a head 198 . Over head 198 and a portion of body 196 is the end piece 180 . End piece 180 provides a circular recess 200 into which pad 182 can be inserted and attached, e.g., by an adhesive. Pad 182 is made of e.g., a high friction elastomeric such as rubber. Knob 176 provides an opening 202 for receiving body 196 of rod 178 . Knob 176 also provides an opening 204 into which nut 174 can be press fit. Nut 174 provides a threaded inner opening 206 adapted to mesh with threaded body 196 of rod 178 . Knob 176 provides an outer surface 208 adapted to be gripped and turned by a user. Three other assemblies similar to assembly 38 are provided (FIG. 1) for insertion into an open end of extension 58 and open ends of cross member 56 (FIG. 1 ).
Referring to FIG. 2, pad 40 is adapted to be mounted to two bars 224 of barrier 46 . Pad 40 is shaped and disposed to be pushed by, e.g., an adult's knee. Pad 40 can be snapped on to bars 224 at various positions.
Frame support 44 is adapted to rest on a flat surface such as the floor and to receive cross member 56 of frame 12 . Support 44 provides an opening 210 along its length sized to receive cross member 56 of frame 12 .
A wrench 300 , as shown in FIG. 9, is provided with gate 10 . Wrench 300 has an open end 302 with an inner opening 304 shaped to receive knob 176 (FIGS. 2 and 7) and to engage outer surface 208 (FIG. 7) of knob 176 so that knob 176 can be turned using wrench 300 . Wrench 300 has a flat handle 306 of a thickness 308 .
Referring to FIGS. 1-7, pieces of gate 10 can be made as follows. Frame 12 and barrier 46 are welded of steel in the configurations shown. Foot pedal 16 , bracket 18 , foot pedal support 42 , pad 40 , and frame support 44 are injection molded acrylonitrile butadiene styrene (ABS). Holes and slots provided by frame 12 can be machined after frame 12 is injection molded or can be formed as part of the injection molding. Caps 172 , knobs 176 , and end pieces 180 are also molded ABS. Springs 36 , 126 and 146 are made of steel, as well as rivets 80 and 84 , nut 174 , and rod 178 .
Gate 10 can be assembled as follows. Linkage 34 is inserted into interior 96 of spring 36 . Linkage 34 and spring 36 are inserted into opening 76 of arm 54 and positioned by inserting pins 90 and 92 into holes 86 and 88 respectively. Foot pedal support 42 is fit onto square side 106 of arm 154 and positioned so that hole 102 and hole 104 align with slot 82 and slot 83 . Rivet 84 is inserted through hole 102 in support 42 , slot 82 in arm 54 , hole 98 in linkage 34 , slot 83 in arm 54 , and hole 104 in support 42 , and flattened in a conventional manner. Foot pedal 16 is fit onto rounded side 110 of arm 54 and snapped onto foot pedal support 42 . Bracket 18 is fit onto rounded side 110 of arm 54 and rivet 80 inserted through hole 132 in bracket 18 , slot 78 in arm 54 , hole 128 in linkage 34 , slot 79 in arm 54 , and hole 134 in bracket 18 and flattened in a conventional manner.
Referring to FIGS. 2 and 7, assembly 38 is assembled and coupled to extension 60 . End piece 180 is injection molded over head 198 and pad 182 is glued into recess 200 of end piece 180 . Cap 172 is press fit into extension 60 . Nut 174 is pressed fit into opening 204 of knob 176 to form a knob assembly 212 (FIG. 7 ). Rod 178 is inserted through knob assembly 212 by turning rod 178 to thread nut 174 onto body 196 of rod 178 . Rod 178 is inserted into sleeve 178 of cap 172 . As rod 178 is inserted into sleeve 188 , threads on body 196 will interfere with tab 192 . Finger 190 will flex to allow tab 192 to move out of the way of threads on body 196 to allow rod 178 to be inserted into sleeve 188 . Other assemblies similar to assembly 38 are similarly assembled and coupled to extension 58 and ends of cross member 56 of frame 12 .
Pad 40 is snapped to a desired location of bars 224 of barrier 46 . Alternatively pad 40 can be permanently fixed by, e.g., sonic welding to barrier 46 . Frame 12 is inserted into frame support 44 such that cross member 56 is received by opening 210 .
Referring to FIGS. 2, 3 , and 7 , upper assembly 48 is assembled and coupled to barrier 46 , which is coupled to frame 12 . Pin 142 is inserted through hole 158 provided in cap 144 . Spring 146 is inserted into cap 144 through an opening 244 (FIG. 2) provided in the top of cap 144 . Spring 146 is placed into recess 162 of flared end 160 of pin 142 and also placed over post 164 of cap 144 . Cap 144 is inserted into opening 152 in an end of barrier 46 and attached to, e.g. by press fitting into, barrier 46 . Lower assembly 50 is similarly assembled, inserted into opening 128 in barrier 46 , and attached to barrier 46 . Barrier 46 is attached, e.g., by riveting, to hinges 20 and 70 (FIG. 1) which are attached to frame 12 e.g., by riveting.
Referring to FIGS. 1-9, in operation, gate 10 is mounted between opposing surfaces and adjusted to fit snugly between the opposing surfaces. To adjust the fit between the opposing surfaces, assembly 38 is adjusted such that pad 182 is pressed firmly against one of the opposing surfaces. Coarse or “macro” adjustment of assembly 38 can be accomplished by pulling rod 178 or pushing rod 178 in directions 214 or 216 . This can be accomplished, e.g., by pulling or pushing on knob assembly 212 . When rod 178 is pulled or pushed in directions 214 or 216 , threads on threaded body 196 of rod 178 will interfere with tab 192 , and finger 190 will flex to allow tab 192 to move out of the way of the threads on threaded body 196 . Fine or “micro” adjustment of rod 178 in directions 214 or 216 can be accomplished by turning knob assembly 212 (e.g., using wrench 300 ) in an appropriate direction until assembly butts up against cap 172 . Further rotation of assembly 212 in this direction causes threads on nut 174 to mesh and interact with threaded body 196 to move rod 178 in direction 214 . Rotation of assembly 212 in the opposite direction will cause rod 178 to move in direction 216 . Each of the other three assemblies 38 on gate 10 can be adjusted in similar fashion. Knob assemblies 212 of assemblies 38 at the top of frame 12 are adjusted until arms 52 and 54 move inward (opposite to directions 57 and 59 ) such that angles 61 and 63 become approximately 90°.
Wrench 300 is used to indicate that gate 10 has been properly secured. Handle 306 is pressed flat against surface 143 of bracket 18 and slid downward toward cross member 56 between bracket 18 and cap 142 . When this is done and assemblies 38 at the top of gate 10 are adjusted properly, handle 306 will contact and encounter resistance from (or will not fit between) bracket 18 and cap 142 due to the selected thickness 308 of handle 306 . Handle 306 thus provides a feeler gauge that indicates that gate 10 is properly secured between surfaces 11 and 13 . When gate 10 is properly secured, at least a desired minimum of static friction exists between pads 182 and surfaces 11 and 13 . For example, enough friction may exist such that a force of less than about 40 pounds against gate 10 will be insufficient to slide pads 182 relative to surfaces 11 or 13 . Also, when gate 10 is properly secured, pins 142 will be sufficiently received within recesses 138 , when gate 10 is in closed position 19 , to inhibit undesired opening of gate 10 . Assemblies 38 can be adjusted to securely fit gate 10 within passageways of about 29 inches to about 34 inches wide.
If gate 10 is in a locked position (FIGS. 1 and 7 ), with door 14 in the closed position 19 and pins 122 and 142 in recesses 118 and 138 , door 14 can be moved to an open position by pressing on foot pedal 16 and concurrently pressing on door 14 . To remove the pins 142 and 122 from their respective recesses 138 and 118 to unlock door 14 , foot pedal 16 , foot pedal support 42 , and linkage 34 provide an actuator for actuating engagement and relative motion of the camming surfaces 121 , 168 , 141 , and 148 . Foot pedal 16 is pressed, e.g., by stepping on foot pedal 16 . When a downward force is exerted on foot pedal 16 that exceeds the required force to compress spring 36 (FIGS. 2 and 3 ), foot pedal 16 will move downward. This also causes linkage 34 , and therefore also bracket 18 , to move downward. Foot pedal camming surface 121 (FIG. 5) will slide against camming surface 168 (FIG. 2) and push pin 122 toward pivot axis 74 , out of recess 118 , and onto flat surface 123 (FIG. 5 ). Similarly, camming surface 141 will slide against camming surface 148 of pin 142 , pushing pin 142 out of recess 138 of bracket 18 and onto flat surface 143 as shown in FIG. 8 . With pins 122 and 142 no longer in recesses 118 and 138 , door 14 is in an unlocked position (FIG. 8) and very little force is needed to move door 14 toward open positions 22 or 24 . The user presses against door 14 , e.g., against pad 40 , to pivot door 14 toward an open position.
If door 14 is in an open position, door 14 can be rotated to the closed position 19 and automatically secured or locked in the closed position 19 . Foot pedal 16 , foot pedal support 42 (FIG. 2 ), linkage 34 (FIGS. 2 and 3 ), bracket 18 , and assemblies 48 and 50 (FIG. 2 ), form a lock for securing door 14 in closed position 19 with respect to frame 12 . Door 14 is moved, e.g., by pushing pad 40 , toward the closed position 19 . As door 14 is rotated from open position 22 toward closed position 19 , camming surfaces 148 and 168 of pins 142 and 162 engage with and slide against camming surface 219 (FIG. 6) of bracket 18 and camming surface 220 (FIG. 5) of foot pedal 16 , pushing pins 142 and 122 toward pivot axis 74 . When door 14 reaches closed position 19 , pins 142 and 122 are spring biased into recesses 138 and 118 respectively. Once pins 142 and 122 are in recesses 138 and 118 , door 14 is in a locked position and is substantially prevented from pivoting toward an open position unless foot pedal 16 is pressed with a sufficient force to compress spring 36 . Similarly, when door 14 is in open position 24 , door 14 can be rotated to closed position 19 , with engaging surfaces 148 and 168 sliding against and engaging with camming surfaces 218 (FIG. 6) and 222 (FIG. 5) of bracket 18 and foot pedal 16 , respectively.
Other embodiments are within the scope and spirit of the appended claims. For example, extension arms can be provided to allow gate 10 to be secured in passageways larger than 34 inches. | An apparatus includes a pair of frame members adapted for mounting to opposing surfaces of a passageway. A door is mounted to at least one of the frame members for movement between a closed position, in which the door and frame members substantially traverse the passageway and an open position, in which a portion of the passageway is free of the door and frame members, the portion being large enough to permit passage of an adult therethrough. A lock is coupled to at least one of the frame members and adapted to retain the door in the closed position, the lock including an actuator adapted to release the lock to permit movement of the door from the closed position toward the open position upon application to the actuator of a force of at least a predetermined weight of a child. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 61/732,034, filed on Nov. 30, 2012, and entitled “Portable Reverse Osmosis Water Purification System,” the disclosure of which is incorporated by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to water purification systems. More specifically, the present disclosure relates to a portable reverse osmosis water purification system.
BACKGROUND
[0003] Reverse osmosis is a filtration method that removes many types of large molecules and ions from solutions by applying pressure to the solution when it is on one side of a selective membrane. More formally, reverse osmosis is the process of forcing a solvent from a region of high solute concentration through a semipermeable membrane to a region of low solute concentration by applying a pressure in excess of the osmotic pressure. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. The membrane is selective in that large molecules or ions are not allowed through the pores in the membrane, but allows smaller components of the solution (such as the solvent) to pass freely. Reverse osmosis filtration has various applications, including drinking water purification, wastewater purification, food industry uses (e.g., for concentrating food liquid), and health care uses (e.g., electrodialysis systems).
SUMMARY
[0004] In one aspect of the present disclosure, a method for operating a reverse osmosis fluid purification system includes receiving an input fluid at an input of the purification system, and performing a fluid purification run cycle on the input fluid. The fluid purification cycle includes pumping the input fluid through a membrane with a pump at a first pressure and first flow rate to generate product fluid and waste fluid. The product fluid is provided to an external system and the waste fluid is provided to a drain port. The membrane is then rinsed after performing the fluid purification run cycle by providing the input fluid to the pump and pumping the input fluid through the membrane at a second pressure less than the first pressure and a second flow rate greater than the first flow rate for a predetermined period of time.
[0005] In another aspect, a method for operating a reverse osmosis fluid purification system includes initiating a disinfection cycle and draining an internal tank to a minimum level. Input fluid is pumped from a fluid source through a membrane to generate product fluid and waste fluid. The flow of the input fluid from the fluid source is then terminated. The product fluid is directed to the internal tank until the internal tank is filled to a maximum level. The flow of the input fluid from the fluid source is then terminated. An amount of the product fluid is pumped from the internal tank through the membrane until the product fluid in the internal tank is at an intermediate level between the minimum and maximum levels. The amount of product fluid pumped from the internal tank forces fluid residing in the fluid path from the pump through the membrane and to the drain port.
[0006] In a further aspect, a method for operating a reverse osmosis fluid purification system includes disconnecting the fluid purification system from a fluid source and waste port, transporting the fluid purification system to a storage location, and connecting the fluid purification system to an electrical source at the storage location. A storage heat cycling mode is then performed in which the product fluid in the internal tank and system is repeatedly heated and circulated through portions the reverse osmosis fluid purification system.
[0007] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic view of an embodiment of a reverse osmosis water purification system illustrating water flow during a water purification cycle with varying fluid pressures.
[0009] FIG. 2 is a schematic view of the reverse osmosis water purification system illustrating water flow during a shut down flush after the water purification cycle.
[0010] FIG. 3 is a schematic view of the reverse osmosis water purification system illustrating water flow during steps of a pure water storage and purge of the reverse osmosis membrane.
[0011] FIG. 4 is a schematic view of the reverse osmosis water purification system illustrating water flow during a recurring heat mode after disconnecting the system from water feed and waste lines.
[0012] While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0013] FIG. 1 is a schematic view of an embodiment of a reverse osmosis water purification system 10 according to the present disclosure. The system 10 purifies a given feed water (by way of reverse osmosis) for use in various applications, such as hemodialysis. The system 10 possesses monitoring for feed water pressure, feed water quality, feed water temperature, pump outlet pressure, product water pressure, product water temperature, product water quality, and membrane performance (percent rejection). A pump provides the pressure required to push water through the reverse osmosis membrane and against a fixed orifice. Fluid controls provide a means of managing flow rates and pressures.
[0014] The system 10 includes a pressure sensor 11 , a reverse osmosis membrane 12 , a valve body 14 including an orifice 16 and solenoid valve 18 , a valve body 20 , check valves 22 and 24 , a valve body 26 , a check valve 28 , a pump 29 , a valve body 30 , a pressure sensor 31 , solenoid valves 32 and 34 , a valve body 36 , a quality sensor 38 , a valve body 40 , a pressure sensor 42 , a quality sensor 44 , a check valve 46 , a tank vent valve 48 , a valve body 50 , an internal tank 52 , a thermal switch 54 , level sensors 56 , 58 , and 60 , a heater 62 , check valves 64 and 65 , solenoid valves 66 and 68 , a check valve 70 , and an external connection 72 . The system 10 also includes a product water output 80 , a return input 82 , an overpressure output 84 , a drain output 86 , and a feed water input 88 . The valve bodies 14 , 20 , 26 , 30 , 36 , 40 , and 50 are configured to control flow rates and pressures in the system 10 . The operation of the system 10 is controlled by a controller (not shown) that is programmed to operate the components of the system 10 to provide various functionalities (e.g., water purification, sanitization, etc.).
[0015] The membrane 12 is connected to the pump 29 at the input of the membrane 12 . The pump 29 controls the fluid pressure through the system 10 . The pump 29 controls water pressure input to the membrane 12 . In some embodiments, the pump 29 includes a variable frequency drive. In some embodiments, the pump 29 has a pump pressure of about 160-200 pounds per square inch (psi) (1.10-1.24 MPa). The pressure sensor 11 measures the pressure of the fluid provided to the input of the membrane 12 . In some embodiments, the output of the pressure sensor 11 is used to control the operation of the pump 29 . For example, the pressure sensor 11 may be configured to shut down the system 10 if the sensor 11 detects an overpressure condition.
[0016] In some embodiments, the membrane 12 is a single membrane comprised of a polymeric material. The membrane 12 may include a dense layer in a polymer matrix, such as the skin of an asymmetric membrane or an interfacially polymerized layer within a thin-film-composite membrane, where the separation of the product water from the waste water occurs. The membrane 12 may have a variety of configurations including, for example, spiral wound or hollow fiber configurations.
[0017] The outputs of the membrane 12 are connected to the valve body 14 (via a waste output) and valve body 40 (via a product output). The solenoid valve 18 of the valve body 14 remains closed during normal operation, such that drain water from the output of the membrane 12 passes through the orifice 16 . During a heat sanitization process, the solenoid valve 18 opens to help maintain the system 10 at a predetermined pressure during the sanitization process.
[0018] The output of the valve body 14 is provided to the check valve 22 via the valve body 20 . The check valve 22 is controlled in some embodiments to reduce flow and maintain a minimum pressure in the fluid path. The output of the check valve 22 is in fluid communication with the check valve 24 via the valve body 26 . In some embodiments, the check valve 24 is controlled in some embodiments to maintain a minimum pressure sufficient to block flow to the drain output 86 . The output of the check valve 24 is connected to the drain output 86 via the valve body 20 . The drain output 86 may be connected to a receptacle or other system for proper disposal of the drain fluid.
[0019] An output of the valve body 26 is also connected to the inlet of the check valve 28 , which located between the feed water fluid path from the input 88 and the fluid path of the drain output 86 and, in some embodiments, is configured to allow waste fluid flow to supply the pump 29 with water, such as during low pressure operation conditions. The output of the check valve 28 is connected to the solenoid valve 34 via the valve body 30 . During a normal water purification cycle, as illustrated in FIG. 1 , the solenoid valve 34 cycles with depending on the level of water in the tank 52 . During heating and chemical sanitization modes of operation, described in more detail below, the solenoid valve 34 operates to isolate the pump 29 .
[0020] The solenoid valve 32 is connected between the feed water input 88 and the valve body 30 . The feed water input 88 may be connected to any pre-filtered fluid source that provides untreated water to the system 10 for purification. The solenoid valve 32 is configured to control the flow of feed water into the system 10 from the feed water input 88 . The pressure sensor 31 monitors the fluid pressure in valve body 30 and in some embodiments is configured to shut down the system 10 if the feed water from the feed water input 88 falls below a threshold pressure.
[0021] The product water output of the membrane 12 is connected to the solenoid valve 66 via the valve body 40 . The solenoid valve 66 is configured to divert product water away from the product water output 80 during certain operations of the system 10 . For example, during system run startup flush, the solenoid valve 66 is closed until the system 10 is producing product water below a water quality set point (e.g., as measured in μS). During heat sanitization and chemical modes, the solenoid valve 66 cycles to direct fluid throughout the system 10 to ensure proper cleaning and disinfection. During normal operation, illustrated in FIG. 1 , the solenoid valve 66 is open to allow product water to be provided to the external connection 72 via the product water output 80 . The external connection 72 may be coupled to a system that uses the product water, such as a hemodialysis machine.
[0022] The pressure sensor 43 is connected between the membrane 12 and the solenoid valve 66 and is configured to monitor the pressure of the product water provided from the membrane 12 . If an overpressure condition is detected by the pressure sensor 43 , the system 10 may respond to reduce the pressure and may be shut down.
[0023] The quality sensor 44 monitors the quality and temperature of the product water after it exits the membrane 12 . The product water quality measured by the quality sensor 44 can be reviewed (e.g., on a screen associated with the system 10 ) during normal operation. An additional display for review is a system calculated percent rejection comparison between the unpurified water flowing in valve body 36 and the purified product water flowing in valve body 40 .
[0024] The input of the check valve 46 is connected between the output of the membrane 12 via the valve body 40 , and the output of the check valve 46 is connected to the input of the internal tank 52 via the valve body 50 . The check valve 46 is controllable to prevent backflow of water in the internal tank 52 into the product water provided to the product water output 80 . The check valve 46 also provides a pressure regulation for the line from the membrane 12 to the product water output 80 .
[0025] The solenoid valve 68 provides fluid flow resistance during normal operation to the unused product water returning from the external connection 72 . In some embodiments, the solenoid valve 68 provides a backpressure to maintain the product water at a pressure of approximately 35 psi (0.241 MPa). During heating operation, the solenoid valve 68 is opened and provides full free flow.
[0026] The return input 82 provides an input to return product fluid via the external connection 72 to the system 10 . For example, in a hemodialysis application, the return input 82 allows fluid not used during dialysis to be returned to the system 10 for re-purification. The return input 82 may also be used to return fluid to the system 10 during heat and chemical cleaning modes of the system 10 .
[0027] The internal tank 52 receives water from the check valve 46 and/or the return input 82 . The vent valve 48 is configured to allow airflow to and from the tank 52 , but not water from the tank 52 . The temperature of the water in the internal tank 52 is monitored by the thermal switch 54 . If the water in the tank 52 exceeds a fixed threshold temperature, the thermal switch 54 provides an indication to the system controller and also removes the control signal from the heater 62 power supply circuit. The level of the fluid in the internal tank 52 is measured by the level sensors 56 , 58 , and 60 . The level sensor 56 is triggered when water in the tank 52 is at or above a maximum water level, the level sensor 58 is triggered when water in the tank 52 is at or below an intermediate water level, and the level sensor 60 is triggered when the water in the tank 52 is at or below a minimum water level. The heater 62 is operable to heat the water in the tank 52 . The check valve 64 is at the outlet of the tank 52 and prevents pump 29 feed water from being fed back into the tank 52 .
[0028] The check valve 65 is connected between the tank 52 and the overpressure output 84 and is configured to prevent the tank 52 from over-pressurizing. The check valve 70 is connected between the drain output 86 and the overpressure output 84 and is configured to relieve pressure in the drain line when the drain output 86 is not connected or not functional.
[0029] FIG. 1 illustrates the water flow during a water purification cycle, in conjunction with water quality monitoring and run flush activities, in which the system 10 purifies feed water supplied at the feed input 88 and provides product water at the external connection 72 via the product water output 80 . In this process, the solenoid valves 18 and 68 and check valves 65 and 70 are closed, while the solenoid valves 32 , 34 , and 66 and check valves 22 , and 24 are open. In some embodiments with lower feed water pressure at input 88 , check valves 28 and 64 open and allow water flow to support the supply to pump 29 . The water from the feed water input 88 is fed through solenoids 32 and 34 via valve bodies 36 and 30 to the pump 29 and forced through the membrane 12 at a pressure controlled using pressure sensor 11 and the pump 29 . In some embodiments, the pressure of the feed water at the input side of the membrane 12 is about 160-180 psi. The product water from the membrane 12 is then provided to the product water output 80 , and the non-recirculating waste or drain water flows through the check valves 22 and 24 to the drain output 86 .
[0030] FIG. 2 is a schematic view of the reverse osmosis water purification system 10 illustrating water flow during a shut down flush after the water purification cycle according to an embodiment of the present disclosure. During the shutdown flush, the membrane 12 is rinsed to clear the membrane surface of high concentration feed water. In some embodiments, the shut down flush is performed automatically and cannot be overridden by the operator of the system 10 .
[0031] In the shut down flush mode, the solenoid valves 18 , 32 , and 34 are open, while the solenoid valves 65 , 66 , 68 , and 70 are closed. Additionally, the check valves 22 , 24 , 28 , 46 , and 64 are open. Thus, the flow path from the membrane to the product water output 80 is closed to divert the product water to the tank 52 . The speed of the pump 29 is controlled to supply the feed water applied by the pump 29 at a pressure less than the pressure during the normal water purification cycle. This allows low pressure, high flow rate water to rush across the outer surface of the membrane 12 . The flushing water flows through the membrane 12 , out the waste output of the membrane, to the drain output 88 . In some embodiments, the shut down flush is performed on the membrane 12 for a programmed period of time. For example, in one implementation, the shut down flush is performed for at least about one minute.
[0032] FIG. 3 is a schematic view of the reverse osmosis water purification system 10 illustrating various water flow paths during a pure water purge, heat sanitization, and or chemical induction of the reverse osmosis water purification system 10 , according to embodiments of the present disclosure. Specifically during the pure water purge step, a contained amount of pure product water is produced and captured. A portion of this captured pure water is then used to force or purge out the high concentration water from the membrane 12 and the waste fluid flow paths to the drain port 86 . The remaining volume of pure water is used for recirculation during heating or chemical induction modes of operation. Specifically, in the chemical mode of operation, a container of chemical sterilant is connected between external connection 72 and the product output 80 for chemical induction by the system 10 . In this induction process the solenoid valves 34 , 66 and 68 are opened, and the solenoid valves 18 and 32 are closed. Additionally, the check valves 22 , 28 , 46 and 64 are opened, and the check valves 24 , 65 , and 70 are closed. This arrangement allows chemical to be circulated through the system 10 . Specifically in the heat recirculation mode of operation, the solenoid valves 66 , 68 and 34 are opened, and the solenoid valves 18 and 32 are closed. Additionally, the check valves 64 , 28 , 22 and 46 are opened, and the check valves 24 , 65 , and 70 are closed. In some embodiments, the chemical is heated to provide increase the efficacy of the sterilant (e.g., at least about 70° F.).
[0033] Upon selecting the chemical or heat mode of operation, standing water in the internal tank 52 is provided to the drain output 86 until the level of water in the tank 52 is at a minimum level. For example, the internal tank 52 will be drained until the level sensor 60 no longer senses water in the tank 52 . The solenoid valves 32 and 34 are then opened to allow the feed water from the feed water input 88 to be provided to the pump 29 , and the system 10 is operated in a normal water purification mode as described previously, but the product water is diverted to the internal tank 52 to refill the tank 52 to a maximum level. For example, product water will be diverted into the internal tank 52 until the level sensor 56 senses water. The solenoid valve 32 is then closed, and the system 10 is operated to again consume the water in the tank 52 down to an intermediate level between the maximum level and the minimum level. For example, product water in the tank 52 is provided to the pump 29 to be forced through the membrane 12 until the water in the tank 52 drops until the level sensor 58 no longer senses water in the tank 52 . In some embodiments, the amount of water consumed in from the tank 52 to reach the intermediate level is sufficient to displace the water in the flow path between the tank 52 and the drain output 86 .
[0034] FIG. 4 is a fluid flow schematic view of the reverse osmosis water purification system 10 illustrating water flow specifically during a recurring heat mode after the purge step and after disconnecting tubing lines from water feed 88 and waste line 86 , according to an embodiment of the present disclosure. When the water purification system 10 is going to be stored for an extended period of time, it is important to maintain the system 10 in a sanitized state such that the system 10 is ready for use when needed. In the recurring heat mode, the solenoid valves 68 and 34 are opened, solenoid valve 18 is closed, and solenoid valve 66 is alternatingly opened and closed in predetermined intervals to allow fluid flow and even heating in the flow paths between membrane 12 product output and system 10 product output 80 , past the product supply port 72 , and on to return port 82 . And alternately the product divert path through check valve 48 and valve body 50 , with both flows returning to tank 52 for re-heating. Additionally check valve 48 allows the tank 52 to breath or exchange air as needed during the heating process.
[0035] The operator of the system 10 can initiate a recurring heat mode when the system 10 is ready to be transported to a storage location. In some embodiments, when the recurring heat mode is initiated, the system 10 may execute a pure water purging step as described above with regard to FIG. 3 . This puts product water into the tank 52 for the recurring heat mode. A display (not shown) associated with the system 10 may then provide the operator with instructions for relocating the system 10 to a storage location to initiate the recurring heat mode. The operator disconnects the feed water line from the feed water input 88 and the drain connection from the drain output 86 , and the system 10 from an electrical source that powers the system controller and other system components. The system 10 is then transported to the storage location and re-connected to an electrical source. The operator can then complete the steps to cause the system 10 to operate in the recurring heat mode while being stored with no ties to feed water or waste connections.
[0036] When started, the recurring heat mode begins by operating pump 29 and the heater 62 to circulate and heat the water in the system 10 to a predetermined temperature. In some embodiments, the predetermined temperature is at least about 176° F. When the system 10 reaches the predetermined temperature, the system 10 cycles the heater 62 to maintain the water at the predetermined temperature for a predetermined period of time. In some embodiments, this predetermined period of time is at least about 30 minutes. After this time, the system 10 allows the water to cool by halting the heating process and continuing to circulate the water through the system 10 . The system may then initiate another heat cycle to heat the water to the predetermined temperature, regardless of the standing system temperature. The system 10 may be programmed by the operator to set the frequency at which the recurring heat cycle is run. In some embodiments, in the event of a failure of the power source while the system 10 is in the recurring heat mode, or resting, waiting for the next recurring heat mode trigger, the system 10 will automatically re-initiate the recurring heat mode upon the return of power, starting with circulation and heating of the water in the system 10 .
[0037] When the system 10 is to be used, the operator can cancel or abort the recurring heat mode. When canceled, the system 10 will exit from the recurring heat mode. If the water in the system 10 is above a programmed temperature (e.g., 105° F.) when the recurring heat mode is canceled, the system 10 enters a cool down mode until the water in the system is below the programmed temperature. The system 10 can then be run by the operator for a period of time (e.g., ten minutes), after which time the system 10 is ready for dialysis use.
[0038] Attached to this application as Appendix A is a document entitled “Mar Cor Purification, Millenium HX Reverse Osmosis Unit, Operation and Maintenance Manual,” which describes aspects of the system 10 and processes described herein, as well as the user interface, housing, and other features of the system 10 . The information in Appendix A supplements the information discussed herein.
[0039] Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof | In a reverse osmosis fluid purification system, an input fluid is received at an input of the purification system, and a fluid purification run cycle is performed on the input fluid. The fluid purification cycle includes pumping the input fluid through a membrane with a pump at a first pressure and first flow rate to generate product fluid and waste fluid. The product fluid is provided to an external system and the waste fluid is provided to a drain port. The membrane is then rinsed after performing the fluid purification run cycle by providing the input fluid to the pump and pumping the input fluid through the membrane at a second pressure less than the first pressure and a second flow rate greater than the first flow rate for a predetermined period of time. | 0 |
DESCRIPTION
[0001] The invention relates to a method for processing mailpieces, whereby the mailpieces are sorted by at least one automated sorting installation.
[0002] The invention also relates to a device that is suitable for carrying out the method.
[0003] The invention is based on the objective of determining, in the most reliable manner possible, mailpieces for which insufficient payment or no payment at all has been made.
[0004] According to the invention, this objective is achieved in that an automated checking procedure is carried out to ascertain whether the mailpiece has the expected postage and in that the completion of the checking of the mailpiece is marked by applying a code onto the mailpiece.
[0005] The payment assurance code is a marking that contains information on the result of each checking procedure that has been performed.
[0006] As a matter of principle, any payment assurance codes can be used. However, it has been found that the use of 2-digit payment assurance codes is suitable for recording all relevant payment assurance events and for integrating them into the further processing of the mailpieces, especially their sorting.
[0007] The use of such a payment assurance code can serve for further process control, for example, to systematically divert mailpieces in case of suspicion of fraud, or else to direct them to additional checking steps that differ from each other and that are a function of the payment assurance code. Moreover, the application of a payment assurance code makes it possible to ensure that a mailpiece only undergoes the payment assurance procedure once and/or that it is only recorded one single time in a mailpiece recording system.
[0008] For this purpose, it is especially advantageous that, in processing the mailpiece, a processing machine checks whether the mailpiece is marked with a payment assurance code.
[0009] An effective recording of all mailpieces that avoids double recording can be advantageously achieved in that data record components of the mailpieces that are not marked are recorded in a data processing system.
[0010] Such a processing step is, for example, a preliminary sorting in a mail center for incoming mail and in a mail center for outgoing mail.
[0011] Another processing step is, for example, a fine sorting in a mail center for incoming mail and in a mail center for outgoing mail.
[0012] Additional advantages, special features and practical refinements of the inventions ensue from the subclaims and from the following presentation of preferred embodiments of the invention.
[0013] The depicted execution forms of the method and embodiments of the device allow the recording and utilization of mailpiece-related data for the process control and for the execution of the processing steps as a function of the acquired data.
[0014] The payment assurance system according to the invention records all machine-readable mailpieces. When an uncoded mailpiece is coded as it passes through the machine, the data is stored in the payment assurance system. When a coded mailpiece is fed into the machine, then data is only recorded if an after-coding has been applied. The recognition of already existent coding is carried out by checking means which, by checking at least one surface, ascertain whether the mailpiece contains a code.
[0015] An especially suitable means for checking is offered by the expanded utilization of automation in the mail centers in order to obtain more detailed information for each automatically processed mailpiece. The result is, on the one hand, the additional diverting of mailpieces into “payment assurance compartments”. On the other hand, data from the reading and checking procedures in the machines is collected and kept on hand for the processes involving each automatically processed mailpiece.
[0016] An especially important feature is the optimization of the procedures in the mail centers and in all of the adjacent areas.
[0017] The invention makes it possible to acquire information for numerous, preferably for all, payment modalities that are possible for the mailpieces.
[0018] The checking of the types of postage can be carried out in various checking steps that are adapted to the particular type of postage.
[0019] The checking of postage generated by means of sender franking machines (SFM) is preferably carried out as follows:
[0020] First of all, the type of postage is identified and checked, in the most automated way possible.
[0021] It is especially advantageous to identify and check the type of postage in an address reading machine (ARM) or in an integrated reading and video coding machine (IRVM).
[0022] Mailpieces that, during the execution of the payment assurance process, deviate from an expected pattern, generate a payment assurance warning. Such mailpieces are handled separately, in particular, they are diverted locally from the mail sequence at a suitable place. It is especially suitable to divert them to the fine sorting machines.
[0023] Diverting the mailpieces to a fine sorting machine has the advantage that the fine sorting machine has more compartments available for the differently diverted mailpieces. This makes it possible to selectively divert the mailpieces involving different scenarios, for example, approximately 10, that have to be considered within the context of payment assurance.
[0024] When mailpieces are examined that have postage that was generated with sender franking machines, preferably all of the postage imprints are recorded.
[0025] An especially advantageous local checking of mailpieces that have been franked with sender franking machines is carried out with the criteria of the machine sorting programs, especially retroactively, optionally manually and on the basis of a positive/negative file.
[0026] The checking of mailpieces having digital postage indicia allows an especially effective checking of the proper franking of the mailpieces, thanks to the large volume of information contained in the digital postage indicia.
[0027] Due to the preferred modality of generating such digital postage in personal computers (PC), this franking modality is referred to below as PC franking. The embodiments, however, also apply to other digital postage indicia that can be generated, for example, by means of suitable large-scale printers or by franking machines that are configured for printing digital postage indicia.
[0028] Another advantage of checking the authenticity of digital postage indicia is the possibility of an automated identification and checking of the type of postage.
[0029] In particular, mailpieces are locally diverted into a sorting machine, especially into a fine sorting machine. Here, mailpieces that trigger a payment assurance warning within the scope of a checking procedure are diverted.
[0030] The further process steps take place essentially according to the preceding example.
[0031] For the payment assurance, the mailing data of the customers who frank their mailpieces by means of PC franking is compiled and supplied in compressed form. The supply of data, for example, customer data, positive and negative file, is to be integrated into the application database franking and into the Postage Point. This is where the mailing data is associated with the customer data.
[0032] The various checking methods are embodiments of a process, involving the recording of the individual mailpiece, the subsequent coding of the mailpiece as a function of the result of a step of a payment assurance method and, if applicable, the diverting of mailpieces that are suspected of non-compliance with the prescribed postage requirements.
[0033] An especially advantageous embodiment of the invention is characterized in that each mailpiece is only read once in the payment assurance system in order to prevent the mailing data from being recorded twice.
[0034] Taking preferred operational sequences into consideration, the following processes for machine-readable and machine-processable mailpieces have been defined:
When an uncoded mailpiece—franking modalities “sender franking machine (SFM)” or “PC franking (PC-F)”—is coded as it passes through the machine, the data is recorded for the payment assurance system. When a coded mailpiece is fed into the machine, no recording is carried out for the payment assurance system (unless an after-coding has been applied). The recognition of an already existent coding is ensured by the technical capabilities at hand. Special rules apply in the case of linear code scanning.
[0039] No coding takes place in the operation mode “LCS OFF” (linear code scanning OFF). However, the postage indicium is read, evaluated and the result is recorded for the payment assurance system. In this case, mailpieces that generate a payment assurance warning can be diverted into a preliminary sorting compartment of the address reading machine (ARM).
[0040] The processing of the mailpieces in mail centers is shown below. Fundamentally, the depicted processing of the mailpieces is suitable for all mail centers.
[0041] The initial processing of a mailpiece in a mail sorting installation, especially in an address reading machine that is integrated into such an installation, results in the recording in the payment assurance system. The coding here depends on the target information and on the machine readability. The mail volumes in the reject compartment of the address reading machine, for example, are not recorded for payment assurance data. Subsequently, processing is carried out once again in the integrated reading and video coding machine (IRVM) or in the video coding machine (VCM). In this embodiment, at the end of the processing in the integrated reading and video coding machine or video coding machine, the mail volume in the reject compartment is not recorded for the payment assurance system in the outgoing mail center (OMC) operation.
[0042] After the last run, the mailpieces in the reject compartment of the integrated reading and video coding machine or video coding machine go to the residual manual sorting station.
[0043] Mailpieces with a payment assurance warning that are returned to the conveying sequence are preferably sorted in the integrated reading and video coding machine or video coding machine by the sorting program of the fine sorting machine (FSM).
[0044] Preferably, this is done in that the address reading machines and the fine sorting machines, or rather the integrated reading and video coding machines, are operated in a special mode that suppresses the sorting according to the payment assurance code contained in the code (“payment assurance (PA) OFF”).
[0045] It is likewise advantageous for the fine sorting machines (FSM), in which there are compartments for diverting the mailpieces with payment assurance features, to be provided with the function “payment assurance (PA) OFF”.
[0046] The processing of uncoded mailpieces with
residual manual sorting (RMS) E+1 COOP mailpieces (LR pre-sorting) mailpieces for address reading machine or integrated reading and video coding machine (incoming mail center—IMC)
by means of the address reading machines, or the integrated reading and video coding machines, in the incoming mail centers results in recording in the payment assurance system of the incoming mail center, as long as they are coded. In this case, the coding depends on the target information and on the machine readability.
[0050] The decision as to whether a mailpiece is coded or uncoded is made by a pre-barcode reader that is integrated into the sorting installation.
[0051] It is especially advantageous for mailpieces that are already coded not to be recorded once again in the payment assurance system and, at the same time, to ensure that all of the uncoded mailpieces are (retroactively) recorded whenever possible.
[0052] It is advantageous to ensure that all payment assurance warnings that become necessary within the scope of the coding in the incoming mail center are encrypted with codes for the positions T1 and T2 that are different from the coding in the outgoing mail center. It is advantageous to also provide the function “payment assurance (PA) OFF” for the sorting and coding aggregates in the incoming mail center as well.
[0053] The mail volumes in the reject compartment of the sorting installation are not recorded for the payment assurance system and they are transported to the residual manual sorting station in the incoming mail center (IMC).
[0054] For a mail volume that was processed in the outgoing mail center (OMC) without linear code scanning and that was already recorded for the payment assurance system in the outgoing mail center, it applies that operational processing in the incoming mail center is only allowed to be carried out in the residual manual sorting station or by means of the sorting program “IMC LCS OFF”, since otherwise—due to the lack of the master code—recording in the system for additional information about mailpieces (AIM) and coding in the incoming mail center would be carried out again.
[0055] The mail volume from linear code scanning OFF programs in the outgoing mail center has to arrive at the incoming mail center in appropriately marked mail containers (MCnr) so that they can be distinguished from the mailpieces that have been recorded by the sorting installation of the incoming mail center. A sorting program “IMC LCS OFF” would prevent data from being recorded twice for the system for additional information about mailpieces because here the recording in the system for additional information about mailpieces would be switched off.
[0056] The checking steps described below are especially well-suited for carrying out the individual checking modalities.
[0057] The mailpieces are fed in a readable manner to a unit of the sorting installation, for example, a coding machine. The pre-barcode reader checks whether the mailpiece has a complete barcode. Mailpieces with complete barcodes enter the normal conveying sequence and are not recorded in the system for additional information about mailpieces. With all of the other mailpieces, the image of each mailpiece is transmitted to the image management module (IMM) and to the connected sender franking machine and 2D barcode reading unit. The image management module and the reading unit check the presented image. If it is a mailpiece with a sender franking machine (SFM) imprint, then the SFM identification and the SFM postage indicium are read.
[0058] If the sender franking machine imprint or parts thereof cannot be read, then a payment assurance warning is automatically coded and the mailpiece is diverted into the “SFM identification not readable” or “SFM postage indicium not readable” payment assurance compartments in the fine sorting machine. If the sender franking machine imprint (SFM identification and the SFM postage indicium) was read, then a procedure checks whether the sender franking machine identification has been recorded in a negative file or in a positive file and/or if the mailpiece has insufficient postage.
[0059] If the sender franking machine identification is in the negative file, then a payment assurance warning is coded and the mailpiece is diverted into the “SFM negative file” payment assurance compartment in the fine sorting machine.
[0060] If the sender franking machine identification is not in the negative file, then a procedure checks whether it is in the positive file. If the sender franking machine identification is not in the positive file, then a payment assurance warning is coded onto the mailpiece and the mailpiece is diverted into the “SFM not in positive file” payment assurance compartment in the fine sorting machine.
[0061] If the sender franking machine identification is in the positive file, then the amount of postage is checked. If the mailpiece has insufficient postage, then a payment assurance warning is coded onto the mailpiece and the mailpiece is diverted into the “SFM insufficient postage” payment assurance compartment in the fine sorting machine.
[0062] If the sender franking machine identification is not in the negative file but rather in the positive file, and if there is sufficient postage, then the mailpiece is coded without a payment assurance warning and it is fed into the normal conveying sequence.
[0063] In a preferably local database, all of the mailpieces identified as coming from a sender franking machine are recorded and the identification is registered with the appertaining postage. This data is supplied for the evaluation and issuing of the local production report.
[0064] In a local payment assurance system, a production report is issued daily, it is augmented by the results of an after-processing of the mailpieces, for example, of a local database, with the following content:
[0065] 1. Time axis (evaluation after the beginning or end of the shift with a window of time of approximately 15 minutes)
[0066] 2. Fine sorting machine (machine data)
[0067] 3. Number of mailpieces per payment assurance event (by machine/after-processing)
[0068] 4. Number of mailpieces per payment assurance compartment (by machine/after-processing)
[0069] 5. Payment assurance codes
[0070] 6. Additional information:
Number of the mail center Date of issue Beginning and end of the recording (time of day)
[0074] The local reports are transmitted to a central database (central system for additional information about mailpieces) every workday after the distribution has been completed and after the input of the supplementary entries.
[0075] In a central payment assurance unit, for example, a central database, essentially the appertaining data of several processing centers is stored and, for each sender franking machine identification, a customer production report having the following content is drawn up:
[0076] 1. Time axis, for example, on the basis of the processing cycles in a mail center
[0077] 2. Sender franking machine identification
[0078] 3. Customer data (Uniform Customer and Product (UCP) number, name, address)—the data is made available by the franking database
[0079] 4. Franking data, including the number of after-processing procedures per payment assurance amount
[0080] 5. Optionally, payment assurance events and diverting data, including after-processing
[0081] 6. Display of mail volume and production, including after-processing
[0082] The data of the customer production report is transmitted to the franking database in order to issue the production account report.
[0083] For each sender franking machine identification, the franking database automatically compresses its own data as well as the data that has been transmitted by the central system for additional information about mailpieces every workday:
cumulative postage amount spent cumulative amount of the paid value cards/value charges.
[0086] On a fixed schedule, the franking database compares the sum of the stamped amounts and the sum of the paid value cards/value charges for each sender franking machine identification read-in during the specified reporting period. If the results of the comparison between the read-in and the paid amounts exceed certain defined limit values, then the franking database automatically exports the data of that particular sender franking machine identification into an “alarm file” that is evaluated and further processed.
[0087] Moreover, the appertaining customer data is entered into the negative file so that it can be updated daily and transmitted to the local payment assurance system via the central payment assurance system.
[0088] Mailpieces that appear to have a digital postage indicium (PC-F) are presented to the advanced color recognizer (ACR). The advanced color recognizer analyzes the front of the mailpiece and compares patterns in an attempt to recognize a familiar type of postage (SFM, PC-F, etc.)
[0089] If PC-franking as the franking modality is recognized, the mailpiece is aligned in Compartment 1 or 2 so as to be readable for the further processing in the coding machines.
[0090] The mailpieces are fed to the coding machine so as to be readable. The pre-barcode reader checks whether the mailpiece has a complete barcode.
[0091] Mailpieces with complete barcodes enter the normal conveying sequence and are not recorded in the system for additional information about mailpieces. With all other mailpieces, the image of each mailpiece is forwarded to a central image management module (IMM) and to the connected sender franking machine and 2D-barcode reading unit. The image management module and the reading unit check the presented image. If it is a PC-franked mailpiece, the 2D-barcode is read.
[0092] If the 2D-barcode cannot be read, then a payment assurance warning is automatically coded and the mailpiece is diverted into the “PC-F negative file/barcode not readable” payment assurance compartment in the fine sorting machine.
[0093] Once the 2D-barcode has been read, and after the decryption of the cryptostring, the following checking procedures are carried out:
checking the PC-franking version checking the Postage-ID comparing the license number with the negative file comparing the hash values checking the date in the 2D-barcode checking the minimum postage
[0100] If the PC-franking version is invalid, then a payment assurance warning is coded and the mailpiece is diverted into the “PC-F version/date/insufficient postage” payment assurance compartment in the fine sorting machine.
[0101] If the PC-franking version is valid, then the Postage-ID is checked. If the postage-ID is invalid, then a payment assurance warning is coded onto the mailpiece and the mailpiece is diverted into the “PC-F suspicion of forgery” payment assurance compartment in the fine sorting machine.
[0102] If the Postage-ID is valid, it is automatically compared to the negative file. If the postage-ID is in the negative file, then a payment assurance warning is coded onto the mailpiece and the mailpiece is diverted into the “PC-F negative file/barcode not readable” payment assurance compartment in the fine sorting machine.
[0103] If the license number is not in the negative file, the hash value is compared. If the hash value is not in order, a payment assurance warning is coded onto the mailpiece and the mailpiece is diverted into the “PC-F suspicion of forgery” payment assurance compartment in the fine sorting machine.
[0104] If the hash value is in order, then the date in the 2D-barcode is checked. If the date in the 2D barcode differs by more than one day from the actual date, then a payment assurance warning is coded onto the mailpiece and the mailpiece is diverted into the “PC-F version/date/insufficient postage” payment assurance compartment in the fine sorting machine.
[0105] If the date in the 2D barcode is valid, then the minimum postage is checked. If the mailpiece has insufficient postage, a payment assurance warning is coded onto the mailpiece and the mailpiece is diverted into the “PC-F version/date/insufficient postage” payment assurance compartment in the fine sorting machine.
[0106] The system recognizes the amount of the postage from the barcode and compares it to the stored values.
[0107] If the 2D-barcode of the PC-franked mailpiece was readable, if the PC-franked version and the Postage-ID are valid and if there is no entry in the negative file, if the hash value and the date are valid and the postage is sufficient, then the mailpiece is coded without a payment assurance warning and it is fed into the normal conveying sequence.
[0108] Mailpieces for which a manual reading and checking procedure with a hand-held scanner confirms that the Postage-ID is invalid or that the hash value comparison is not correct, are correctly diverted. The mailpieces are taken out of the conveying sequence for evidentiary purposes.
[0109] Mailpieces for which a manual reading and checking procedure with a hand-held scanner confirms that the mailpiece has insufficient postage are returned to the sender or else they receive the necessary supplementary postage and are delivered to the recipient.
[0110] Mailpieces for which a manual reading and checking procedure with a hand-held scanner confirms that the Postage-ID is supplied in the negative file are removed from the conveying sequence.
[0111] In a preferably local database, all mailpieces identified as PC-F are recorded and registered. This data is provided for the evaluation and issuing of the local production report.
[0112] In a local payment assurance unit that is especially provided with a local database (local system for additional information about mailpieces), a production report—augmented by the results of an after-processing of the mailpieces—is automatically drawn up, for example, daily by the person who checks for compliance with the General Terms and Conditions, and this report has the following content:
[0113] 1. Time axis (evaluation after the beginning or end of the shift with a window of time of preferably at least 15 minutes)
[0114] 2. Fine sorting machine (machine data)
[0115] 3. Number of mailpieces per payment assurance event (by machine/after-processing)
[0116] 4. Number of mailpieces per payment assurance compartment (by machine/after-processing)
[0117] 5. Payment assurance codes
[0118] 6. Additional information:
Number of the mail center Date of issue Beginning and end of the recording (time of day)
[0122] The transmission of the local reports to the central system for additional information about mailpieces is preferably carried out every workday after the distribution has been completed and after the input of the supplementary entries.
[0123] In a central payment assurance unit, which preferably interacts with a central database, essentially the appertaining data of several processing centers is stored and, for each license number, a customer production report having the following content is drawn up:
[0124] 7. Time axis (=mail center-day)
[0125] 8 License number
[0126] 9 Customer data (UCP number, name, address)—the data is supplied by the franking database
[0127] 10. Franking data, including the number of after-processing procedures per payment assurance amount
[0128] 11. Optionally payment assurance events and diverting data, including after-processing
[0129] 12. Display of mail quantity and production, including after-processing
[0130] In order to be able to draw up a production-postage amount report in the franking database, the spent postage amounts calculated on the basis of the utilization profile from the Postage Point are transmitted to the database and collected there. The time intervals depend on when the customer last had contact with the Postage Point (at the latest every three months).
[0131] Once the most recently requested postage amount of every single customer has been transmitted from the Postage Point to the franking database and once the production reports for each customer are available, sorted according to license number, then the franking database automatically generates a daily updated production postage amount report, sorted according to license number:
[0132] 1. License number
[0133] 2. Cumulative franking amount of all mailpieces recorded in the customer production report (production value)
[0134] 3. Spent postage amount calculated on the basis of the utilization profile
[0135] 4. Postage amount from the Postage Point
[0136] Preferably daily, the cumulative franking amount of all mailpieces recorded in the production report for each customer is compared to the postage amount from the Postage Point and the results are stored. If the production value according to the report is higher than the postage amount, then the franking database automatically exports the customer data into an “alarm file”. Moreover, the customer data is entered into the negative file so that this file is updated daily and can be transmitted via the central payment assurance system—central system for additional information about mailpieces—to the local payment assurance system—local system for additional information about mailpieces.
[0137] A local checking means is available for the processing of the diverted mailpieces. The local checking means consists of a data acquisition unit, a graphic display unit, one or more input units, a scanner and optionally additional peripherals such as a printer for printing labels and mail scales.
[0138] This device can be employed individually in the direct vicinity of the alignment and sorting machines. The data feed or network feed takes place via existing interfaces (traffic lights) in the production.
[0139] Processing programs that are modularly adapted to the franking modalities (for example, sender franking machines and PC-franking) support the recording, evaluation and documentation of the detected franking modalities.
[0140] The connected hand scanners (wireless/hard-wired) provide information on the characteristics as well as on the decrypting of the 2D barcode with the support of a crypto-server.
[0141] The mail scales serve to check the payment, a (planned) label printer allows the production of stickers for returning mailpieces, or for printing labels to collect additional postage due.
[0142] The embodiments shown here are intended only by way of example.
[0143] The depicted method for processing mailpieces and the device shown can have a large number of different embodiments in order to fulfill different functions.
[0144] In all of the embodiments, the use of payment assurance codes provides effective protection of the postal service provider against misuse and it links this protection to comprehensive data protection of the customer of the postal service provider while ensuring full compliance with postal confidentiality requirements.
Term Definition 2D barcode Two-dimensional matrix code that is printed onto the mailpiece and that contains mailpiece-specific information in machine-readable form. Sender Actual contractual partner of Deutsche Post. Party required to make the postal conveyance payment. Does not have to be identical to the party mailing or producing a mailpiece. ACR → Advanced color recognizer Advanced color recognizer Technical device for recognizing stored postage stamps (and optionally other types of postage) on the basis of a simple image. Sender-recipient relation Who sends mailpieces within Germany to which postal code region? Who sends mailpieces abroad? Sender-franked Mailpieces that are printed with the postal conveyance payment by the mailing party, using a franking machine for purposes of payment. Sender franking machine Technical device for franking mailpieces. The required payment is printed directly onto the mailpiece. The frank- ing machine user buys a “credit” from the postal service provider. With each franking imprint, the credit is reduced by the amount set on the machine. Sender postage cancella- Cancellation of the postage stamp with an imprint by the tion producer prior to mailing (only for the Infopost and Info- letter products) SFM identification 7-character alphanumeric identification of the sender franking machine of a customer of the postal service pro- vider. The first position contains a letter that identifies the manufacturer of the machine, the next 6 characters iden- tify the customer of the postal service provider. GT&C examiner An employee in the mail center. During the operation, he checks whether the mailpieces that have been submitted for conveyance are in compli- ance with the “General Terms and Conditions (GT&C) of the Deutsche Post”. ARM Address reading machine AM Alignment and stamping machine Address field The area on an envelope that is detected by the reading means of the address reading machine/integrated reading and video coding machine in order to read the address (street, house number, P.O. Box, postal code and city) of the recipient. Diverting Mechanical diverting of certain mailpieces into a compart- ment intended for this purpose. Barcode Barcode with which the recipient address and the payment assurance warning is coded. 2D barcode Recognition feature of the PC-franking modality 2D barcode reader Reading device in the image management module (IMM) that can read, decrypt and check the barcode Cash franking Making a cash payment for a mailing at a branch of Deutsche post. The mailpieces receive a postage indicium as proof of payment. Conveying sequence Term for all of the processing steps that a mailpiece undergoes in the mail center. BMF Federal German Ministry of Finance: issuer of the postage stamp Mailpieces All mailpieces that are processed via the mail centers: let- ters, postcards, books, goods, Infopost/catalog, Info- letter/catalog, bulk mail, mail for the blind (free of charge) Additional mail services The sender can make use of one or more additional ser- vices for some products in exchange for payment of an additional fee. Additional services are: registered, drop-off registered, addressee-only, return receipt, C.O.D. These additional services call for a handling of the mailpieces that differs from the normal processing. MC Mail center OMC window of time The time that is available for a mail center to process the mailpieces until the vehicles leave (main sequence). AMS Additional mail services CCCS Customer Care Center Software; distribution information system that is used by the business-customer service (CallCenter) in Bielefeld, Germany for the documentation of communication with customers. Hand-held sensor Technical device for manually checking the authenticity of postage stamps FRANKING database The FRANKING database (FDB) contains customer-spe- (FDB) cific data of all sender franking machine and PC-franking customers, and it is the basis of the automatic payment assurance. Direct Marketing Center The Direct Marketing Centers handles customers with a (DMC) mail volume of up to 25,000 German marks per year. The objective of the Direct Marketing Center is to generate a larger volume of advertising mail. DP franking Data processing (DP) program of the customer that, after certain information has been entered, determines the amount to be paid for that particular mailpiece and prints this onto the mailpiece. The individual mailpieces are numbered consecutively. The total payment for a mailing is withdrawn from the customer's account by the compe- tent regional accounting center. Mailing party The producer of a mailpiece. Does not have to be identical to the sender. MC for mailing The mail center that is in the area where the postal cus- tomer mails his mailpieces. Mailing date The date on which the customer mails a mailpiece, for example, at a postal service branch. Collection of fee for Payment for the effort on the part of the Deutsche Post in postage due collecting the insufficient postage. UCP no. Uniform customer and product number. Recipient Addressee of a mailpiece. Not a contractual partner of the Deutsche Post. Payment The amount that has to be paid to the Deutsche Post for the service of conveying a mailpiece; types of postage Date of recording The date on which a mailpiece passes through the sorting machine Investigation office Organizational unit of the Deutsche Post; responsible for the preliminary investigation of incidents that are detrimental to the Deutsche Post and that are caused by internal persons (employees) and external persons. In criminal cases, it is the liaison between the Deutsche Post and the public prosecutor's office. PA Payment assurance: all measures that contribute to the Deutsche Post receiving the payment it is owed for the services it has provided. PA compartment Compartment of the fine sorting machine that is available for diverting mailpieces out of the payment assurance system. Branch regional Organizational unit of the Deutsche Post, liaison between management the franking machine manufacturer, the franking machine owners and the MAIL COMMUNICATION business- customer service. Fluorescence Component of postage stamps; chemical substance that becomes visible as a result of irradiation with ultraviolet light and that is needed in the stamping machines so as to recognize postage indicia and to align the mailpieces. Franking Postal term for the payment of the amount required for the conveyance of a mailpiece. Franking modalities Payment options for the conveyance of mailpieces. The following distinction is made: postage stamps, sender franking, cash franking, data processing franking, franking service, PC-franking Postage indicium Marking on a mailpiece indicating that the payment for the total mailing has been paid in cash at an office of the Deutsche Post. The postage indicium contains the name of the office. The value of the mailpiece payment is not indicated. Franking imprint Imprint applied onto the mailpiece by means of a franking machine as proof of payment. The franking imprint con- sists of: payment stamp showing the sender franking machine identification, the mailpiece payment, the words “Deutsche Post AG” or “Deutsche Bundespost” and the drawing of the Post Horn, the date stamp indicating the date and the agreed-upon mailing location (postal code and place), the advertising field of the sender. Infopost or Infoletters contain the supplement “postage paid” in the franking imprint or the product information. Currently, the imprint is applied in red ink. For purposes of better machine-readability, a more high-contrast blue ink will be used in the future. Franking machine Sender franking machine FPIL Franking party InfoLine (FPIL), a database analysis tool of the payment assurance in the Mail Business Division of the Deutsche Post. It utilizes the data of other Business Divisions acquired within the scope of the sender franking and organizes as well as compresses this data under the aspect of payment assurance. FSM Fine sorting machine OL Oversized letters BCS Business-customer service MAIL COMMUNICATION, in Bielefeld, Germany. Responsible for all contractual matters having to do with sender franking machines. Maintains the master data of the “franking” database. Hand-held scanner Technical device for reading a 2D barcode. It is employed for checking purposes with PC-franking if the barcode reader malfunctions or else for checking purposes. Hash value Function for encrypting data that is transmitted via the Internet (Storage) history The stored versions of files are archived separately and logically with their appertaining storage date. IRVM Integrated reading and video coding machine IMM Image Management Module Transit time The time duration for conveying a mailpiece from the time it is mailed by the customer to the time it is delivered to the recipient. The postal service has laid down certain transit times for its products as its quality target. Transit time delay Prolongation of the transit time due to certain events. LCS Linear code scanning Local system Here: local computer for additional information about mailpieces in each mail center Marketing plan In the marketing plan, target specifications are defined for the sales and turnover of each product of the Deutsche Post. Master function Central access to the local computer for additional information about mailpieces Minimum franking value Corresponds to the payment of the “cheapest” form of mailing. At the current time, this is Infopost Standard National = 0.47 German marks Additional postage due In case of insufficient postage: additional payment = collection fee + difference from the correct franking. As a matter of principle, insufficiently franked mailpieces are diverted in the outgoing mail center and returned to the sender. If no sender information is available, the mail- pieces are delivered with additional postage due. Negative file In dubious cases, the negative file contains certain sender franking machine identifications (if applicable, also permissible ones) and customer data of the PC-franking. This file is created and maintained centrally. PC-F customer system The PC-F customer system comprises the hardware and software that are used by the customer for PC-franking. PC-F PC-franking PC-franking New form of franking at the Deutsche Post with which customers can use a conventional PC with a printer and additional software and, if applicable, hardware as well as an Internet access in order to be able to print “digital post- age indicia” onto domestic letters, etc. Postal code cluster Individual postal codes will be combined into postal code clusters within the scope of the project for additional information about mailpieces in order to reduce the data stock and to render it more transparent. Postage amount The amount that is loaded electronically into a “wallet” in the PC-franking customer system and used for the produc- tion of postage indicia. Positive file The positive file contains all of the permissible sender franking machine identifications with the appropriate postal code according to the date stamp. It is provided centrally by the FRANKING database (FDB) every day and updated by the MAIL COMMUNICATION business- customer service, in Bielefeld, Germany. Postage Point The Deutsche Post makes a Postage Point available on the Internet through which postage amounts can be loaded. Mail suppression Unauthorized removal of mailpieces from the operating sequence; criminal offense. Pre-barcode reader Component of the mail sorting installation that scans all mailpieces for the presence of codes. This makes it possi- ble to avoid double coding as well as to apply after-coding by diverting the mailpiece into a separate compartment. PS Postage stamp; type of postage RMS Residual manual sorting Key data (PC-F) The key data consists of a random number and the specification ID. The specification ID contains informa- tion on the identity of the customer, on the specification itself and on the validity of the postage indicia produced with this specification. The key data is made available in the Postage Point. Scoring model Models that automatically trigger actions in case of significant changes. Example: if the utilization pattern of a customer changes, the distribution employee in charge should be notified. SF Super-fluorescence SFS Super-fluorescence sensor Mailpieces without code Mailpieces that have no address and payment assurance coding S/Cmp Standard/compact mailpiece Mwc Mailpiece without code Super-fluorescence Substance that makes it possible to check the authenticity of postage stamps by means of a super-fluorescence sen- sor or a hand-held sensor. Super-fluorescence sensor Technical device in the alignment machine that checks the authenticity of postage stamps. Sales Economic index: sales = quantity * unit price; here: 1. Value of the conveyed mailpieces (total of individual payments of all mailpieces that have been mailed by a customer) 2. Credit purchased from the Deutsche Post by the cus- tomer (e.g. purchased value cards for a certain franking machine) Sales analysis For individual customers, the following sums (sales) are compared: ”Value of the mailpieces that have been mailed” (sum of the postage values) and payments collected from the cus- tomer (e.g. purchased value charges for franking machines). Insufficient postage Shortfall of the payment required for a mailpiece accord- ing to the General Terms and Conditions. Example: the required payment for a standard letter is 1.10 German marks, but the mailpiece is only franked with 0.80 German marks. VCM Video coding machine Verification Verification by checking the correctness. The mailpieces that are automatically diverted out of the system are checked manually by the GT&C examiner to ensure that the diverting was correct. Specification ID Number generated in the Postage Point that contains information about the identity of the customer, about the specification and about the validity of the postage indicia produced with this specification. Central distribution Employee of the central distribution control department controller (Dept. 142) in the center. AIM Additional Information about Mailpieces | Disclosed herein are a method and device for processing postal articles. According to the disclosure, the method includes automatically verifying whether a postal article has an expected prepayment and placing a verification on the postal article where the postal article has the expected prepayment. | 1 |
FIELD OF THE INVENTION
The present invention relates to a device. A plurality of partially overlapping paddles are pivotably fastened on an endless holder for guiding printed products.
DESCRIPTION OF THE PRIOR ART
A device for delivering printed products from a folding apparatus of a web-fed rotary printing press is known from CH 682 230 A5. This device consists of an endless chain conveyor, on each of whose links a paddle and a clamping element are each arranged. One printed product is respectively received between the paddle and the clamping element and is deposited at another processing station.
The object of the present invention is based on providing a device which delivers printed products in an imbricated or overlapping manner on a delivery belt.
In accordance with the present invention, this object is attained by using a printed product guiding device which utilizes a plurality of pivotable paddles attached to an endless holder. The paddles or blades are partially overlapping and define an arrangement of printed product receiving pockets.
The advantages which can be achieved by means of the present invention reside, in particular, in that, assuming the same production speed, each printed product which has fallen into a paddle pocket can have a dwell time which is several times longer than in a pocket of, for example, a known prior art paddle wheel. Even at high production speeds, the printed products can be steadied and aligned after having been received in the paddle pockets of the present invention.
Because of the pivoting movement of the paddles, the printed products slide more slowly, and therefore are placed in better alignment, on the delivery belt. This is advantageous in particular when using non-curved paddles, which can be produced in a simple manner.
With a further embodiment of the invention, the dwell time of the printed products in the paddle pockets can be extended by means of the arrangement of a delivery path. The printed products can be pushed out of the paddle pocket more gently by means of this arrangement and an improved delivery quality can therefore be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is represented in the drawings by means of several preferred embodiments and will be described in greater detail in what follows.
Shown are in:
FIG. 1, the schematic representation of a lateral view of a delivery device in a first preferred embodiment with two chain wheels;
FIG. 2, a representation analogous to FIG. 1, but of a second preferred embodiment with more than two, for example three, chain wheels;
FIG. 3, an enlarged representation of the paddle chain in accordance with FIG. 1, which is guided around the upper chain wheel, but with a lever system which reduces the deflection of the paddle tips when the paddle chain is reversed;
FIG. 4, a lateral view of two paddles with the paddle chain symbolically represented;
FIG. 5, a lateral view of the paddle chain with tongues, but without paddles; and in
FIG. 6, a schematic representation of a lateral view of a delivery device in a third preferred embodiment with a paddle wheel, which has a plurality of paddles.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A delivery device 2 for printed products is arranged underneath an outlet wedge, for example, of a known belt guide system 1 , as seen in FIG 1 . The delivery device 2 has two spaced wheels, each respectively fastened on a shaft 4 , 6 , with the wheels being used for guiding a carrier or traction means. The wheels are designed as chain wheels 7 , 8 , for example, and the traction means is provided as an endless roller chain 11 , for example. The shafts 4 , 6 of the chain wheels 7 , 8 are seated or supported at their left and right ends on lateral frames—A lateral frame 3 is represented in FIGS. 1 and 2. The chain wheels 7 , 8 are arranged one on top of the other, so that the roller chain 11 extends approximately vertically with respect to the direction of a product take-away conveying installation, for example a delivery belt 9 extending in the horizontal direction. The first chain wheel 7 is located in the vicinity of the end of the belt guide system 1 which feeds products to the delivery device 2 . The second chain wheel 8 is arranged in the vicinity of the delivery belt 9 which takes products away from the delivery device 2 .
The chain wheels 7 , 8 together conduct the endless roller chain 11 , which has paddles 12 on its chain links 22 as seen more clearly in FIG 3 . The paddles 12 are fastened on the chain links 22 in such a way, that the paddles 12 partially overlap in the manner of fish scales paddle pockets 13 , for receiving printed products, are formed between each two paddles 12 arranged one behind the other. These product receiving paddle pockets 13 are open opposite the direction of movement of the roller or paddle chain 11 again as shown in FIGS 1 and 2 .
The first chain wheel 7 can be designed as a reversing wheel and the second chain wheel 8 as a drive wheel for the paddle chain 11 . The paddle chain 11 moves in a counterclockwise direction in such a way that a printed product released by the belt system 1 can fall into each paddle pocket 13 .
The distance between the upper and lower chain wheels 7 , 8 can be greater than the distance between five paddles 12 , for example, or also be a multiple of a diameter of a chain wheel 7 or 8 . A plurality of paddles 12 can be arranged on the paddle chain 11 , for example 35 to 45 such paddles 12 can be carried on the chain 11 .
Because of the force of gravity, the printed products can align themselves on a vertical, straight alignment and steadying path A, located between the first and second chain wheel 7 , 8 viewed in the running direction of the claim 11 . Further alignment of the products takes place on a subsequent curved steadying path B extending in the vertical direction. Alignment of the products in the pockets 13 takes place entirely on the paths A and B.
In accordance with another preferred embodiment, it is possible to arrange two smaller chain wheels, not specifically represented, in place of the second chain wheel 8 used in configuration shown in FIG. 1 . In place of the large radius r 8 of the claim wheel 8 , there would therefore be two smaller radii available for reversing the traction means. The traction means or chain 11 then would extend horizontally between the two smaller radii, for example. A delivery path would then be formed. It is also possible to provide known technical means for aligning the printed products. In this way a defined spacing between the printed products is achieved.
The delivery belt 9 , which is itself known per se, is designed in such a way that the upper belt 14 travels in the same direction as the direction of rotation of the second chain wheel 8 .
A guide device 16 can be provided along the steadying tracks A, B and is used for supporting the ends of the printed products projecting out of the paddle pockets 13 . For example, this guide device 16 can have a plurality of rods arranged next to each other and each extending in the vertical direction.
A known product removed device 15 , for use in slipping the printed products out of the pockets 13 is arranged underneath the second chain wheel 8 and extends about at an angle, of approximately 135° in respect to a horizontal line 10 .
In accordance with a second preferred embodiment of the present invention there is provided a delivery device 21 above the delivery belt 9 . This second printed product delivery device 21 is generally similar to the first printed product delivery device 2 with the primary difference being that a further, or third chain wheel 18 arranged on a third shaft 17 is provided. Now two chain wheels 8 , 18 are located above the delivery belt 9 as shown in FIG. 2 . The two chain wheels 8 , 18 can be arranged at a relatively large distance, but can also be positioned closely one behind the other. A plurality of paddles 12 , for example 50 to 60, can be arranged on a paddle chain 19 in this second delivery device 21 .
Together, the chain wheels 7 , 8 , 18 guide the endless roller or paddle chain 19 , which is designed analogously to the paddle chain 11 of the first delivery device 2 . Because of the arrangement of the third chain wheel 18 , a delivery path D is created between the second chain wheel 8 and the third chain wheel 18 , along which a gradual, or a gentle removal of the printed products out of the paddle chain 19 is made possible. This is achieved in that the paddle chain 19 moves on a line 25 which is held parallel in respect to the upper belt 14 of the delivery belt 9 in the area of the printed products delivery path D. A product removal device 20 is arranged at a larger obtuse angle of approximately 150° in respect to the parallel line 25 . The delivery quality of the printed product is improved in this way.
The second or the third chain wheels 8 or 18 can be used as the drive wheel.
Depending on the width of the printed products, several chain wheels 7 , 8 , 18 will be arranged at axial distances from each other on each shaft 4 , 6 , 17 , each of the chain wheels 7 , 8 , 18 support endless paddle chains 18 and together they receive the printed products in a paddle pocket 13 .
Other traction means, such as belts, toothed belts or cables can be used in place of roller chains 11 or 19 in the first two embodiments 2 and 21 .
The paddle chain 11 , 19 can be designed as described in a manner as follows, and as shown, for example in FIGS. 3 to 5 . The chain links 22 are alternatingly designed as inner links 38 or as outer links 39 , as depicted in FIG. 5 . Each chain link 22 is connected by means of chain bolts 23 with the neighboring chain link 22 . Selected ones of the chain links 22 have tongues 34 pointing in the direction of the paddles 12 and separated longitudinally from adjacent tongues 24 at a clear distance e of two chain links 22 as seen in FIGS. 4 and 5. The tongues 24 are fastened alternatingly and opposite each other on both inner links 38 and on an outer links 39 of claim 11 or 19 . The tongues 24 respectively each have a bore for receiving a common bolt 26 . The bolt 26 supports a two-armed paddle holder 27 , which is pivotably seated on the chain link 22 .
A first arm or paddle arm 41 of the paddle holder 27 receives the paddle 12 , which has a paddle tip 28 . A second arm or control arm 29 pointing in the direction of the paddle chain 11 , is for example embodied to be L-shaped, i.e. as an angled lever. The end of the second or control arm 29 points in the direction opposite the tongues 24 and is connected with a first end 31 of a coupler 32 , or of a coupler 33 with these couplers 32 and 33 being shown in FIG. 3. A second end 34 of the coupler 32 , or of the couple 33 , is hingedly connected with the seventh trailing chain bolt 23 .
Each coupler 32 , 33 is generally U-shaped, for example. So that the couplers 32 , 33 do not interfere with each other when their ends overlap, they are oriented so they face each other with their open U-shaped elements. Moreover, the couplers 32 are arranged on one side of the paddle chain 11 , 19 in the conveying direction, and the couplers 33 are arranged on the other side of the paddle chain 11 , 19 .
The paddle holders 27 are designed in such a way that a projection 37 extending in the vicinity of a paddle bottom 36 is narrower than an opening between the two angled control arms 29 . The projection 37 of a paddle holder 21 can therefore be introduced into the opening between the two control arms 29 . A solid guidance of the individual chain links 22 is provided in this way. Therefore the paddles 12 partially overlap each other.
The paddle holders 27 , and therefore the paddles 12 , are pivotably seated on the paddle chain 11 , 19 because of the arrangement of the couplers 32 , 33 between the control arms 29 of the paddle holders 27 and a trailing chain bolt 23 of the paddle chain 11 , 19 . Therefore a radius r 28 of a curve, through which the paddle tips 28 , including the couplers 32 , 33 , pass in the reversing area of the paddle chain 11 , 19 , is less than would be the case without the inclusion of the couplers 32 , 33 . This is of particular advantage in the reversing area of the paddle chain 11 , 19 around the lower chain wheel 8 shown in FIG. 1, because the printed products are delivered to the delivery belt 9 by gentle removal, which aids in increasing the delivery quality.
In order to achieve a comparatively small radius r 28 of the paddle tips 28 in the reversing area of the paddle chain 11 , 19 , it is also possible to attach freely rotatable control rollers on the control arms 29 , instead of the couplers 32 , respectively arranged between the control arms 29 and the paddle chain 11 . These control rollers will then roll off, frictionally connected, on a control cam fixed in place on the lateral frame. The result of this is that a radius r 29 of a curve, through which the ends of the control arms 29 pass in the reversing area of the paddle chain 11 , 19 , is less than a radius of a chain wheel 7 , 8 .
It is furthermore possible to attach a clamping device in the paddle bottom 36 of each paddle holder arm 41 , which clamps the printed product after it has been placed into the paddle pocket 13 and only releases it again prior to reaching the removal device 15 , 20 .
Such a clamping device can consist of a movable clamping jaw, on which a spring force acts, and which acts against the fixed paddle holder arm 41 . For example, by means of a cam-controlled lever arm, the movable clamping jaw can be temporarily brought into an opening position, i.e. for picking up and releasing printed products.
In accordance with a third preferred exemplary embodiment of the present invention, as seen in FIG. 6, a steadying path C extending in a vertical direction has a curved section. Here, an endless carrier, for example a ring-shaped paddle holder 42 of a paddle wheel 43 , is used. The paddle holder 42 is supported by means of spokes 44 , which are connected with a hub 46 in a radial direction. The paddle wheel 42 has a plurality of paddles 12 , for example 35 to 65 paddles 12 , on the circumference of its ring-shaped paddle 12 holder 42 . The paddles can be designed straight, or also can be slightly curved. The printed products are delivered in an imbricated or shingled manner on a delivery belt 9 by means of a removal device 47 .
While preferred embodiments of a device for guiding printed products in accordance with the present invention have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that a number of changes in, for example, the type of printing press used to print the products, the type of belt guide system used to supply the printed products to the device for guiding the printed products, and the like may be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the following claims. | Printed products are guided from an infeed to a delivery belt by a plurality of partially overlapping paddle blades. The paddle blades are secured to an endless carrier such as a chain or a toothed belt. The printed products are deposited on the delivery belt in a smooth, gentle manner as they slip out of the pockets defined by the adjacent overlapping paddles. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to and claims priority under 35 U.S.C. 119(e) to U.S. Application Ser. No. 61/393,665, filed Oct. 15, 2010, entitled “BALLISTIC ARMOR SYSTEM,” the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to light weight armor components having enhanced capability to deflect and damage ballistic projectiles and threats.
2. Description of the Related Art
In recent years armor designs have moved away from homogeneous metallic plates. Current designs often use a range of materials, including: metals (e.g. steel, aluminum, titanium), ceramics (e.g. alumina, boron carbide, silicon carbide), and various fibers and polymers (e.g. aramids, polyethylene, S-2 glass). U.S. Pat. Nos. 5,149,910 and 4,739,690 exhibit this approach.
U.S. Pat. No. 4,739,690, entitled “Ballistic Armor with Spall Shield Containing an Outer layer of Plasticized Resin,” describes the use of layers of different materials to progressively manage the absorption of energy from a projectile. The contents of these and the other patents referenced in this application are incorporated by reference in their entirety.
U.S. Pat. No. 5,149,910, entitled “Polyphase Armor with Spoiler Plate,” describes the use of a corrugated spoiler plate to initiate a “chain of events” as part of an overall armor solution that consists of a spoiler plate, alumina ceramic cells, and an aluminum backing. U.S. Pat. No. 5,736,474, entitled “Multi-Structural Ballistic Material,” describes embedded structures intended to alter a bullets path and/or divert by crush the bullet structure. This patent specifies the use of ballistic resistant woven and nonwoven fibers that act as packaging and support for the divert structures, and serve to absorb energy directly. Accordingly, modern armor solutions employ a variety of materials to arrest ballistic threats.
SUMMARY OF THE INVENTION
In one embodiment of the invention, there is provided an armor having at least one serrated plate or louvered plate assembly. The serrated plate has a base, recessed lands, raised lands, and columnar projections extending from the recessed lands to the raised lands to form serrations on the serrated plate. The louvered plate assembly includes a series of flat plates, oriented at an oblique angle with respect to the ballistic threat.
In one embodiment of the invention, there is provided a method for projectile neutralization. The method includes impacting the projectile on at least one serrated plate having a base, recessed lands, raised lands, and columnar projections extending from the recessed lands to the raised lands, or impacting the louvered plate assembly that includes a series of flat plates oriented at an oblique angle with respect to the ballistic threat. The method includes reducing a kinetic energy of the projectile and re-orienting the projectile upon rupture through the at least one serrated plate or louvered plate assembly.
In one embodiment of the invention, there is provided a system for projectile neutralization. The system has an armor plate (serrated or louvered) configured to reduce a kinetic energy of the projectile and re-orient the projectile upon rupture through the armor plate. The system has a projectile-receptor configured to capture the projectile after rupture through the armor plate.
It is to be understood that both the foregoing general description of the invention and the following detailed description are exemplary, but are not restrictive of the invention.
BRIEF DESCRIPTION OF THE FIGURES
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1A is a depiction of the composition and construction of a .50 caliber AP M2 bullet;
FIG. 1B is a depiction of a projectile impact orientation on an armor panel;
FIG. 2 is a photographic depiction showing three of the projectiles from Table 1;
FIG. 3 is a depiction of a serrated armor plate of the invention showing a size, a depth of serration, a width of serration of the plate;
FIG. 4 is a detailed cross section of a serrated armor plate of the invention;
FIG. 5 is a depiction of a double-sided serrated armor plate of the invention showing a size, a depth of serration, a width of serration of the plate;
FIG. 6 is a depiction of a specific single face serrated design of the invention;
FIG. 7 is a depiction of 1) a concave serrated design of the invention and 2) a contoured serrate design of the invention;
FIG. 8 is a depiction of computer simulation results of a hardened steel serrated plate interaction with a 0.50 AP M2 projectile;
FIG. 9 is a depiction of an armor system of the invention having multiple serrated plates and a projectile receptor.
FIG. 10 is a depiction of a louvered plate assembly invention showing a size, an angle, and an arrangement of the assembly;
FIG. 11 is a detailed cross section of a louvered plate assembly;
FIGS. 12A and 12B are depictions of a specific design of the invention; and
FIG. 13 is a depiction of computer simulation results of a louvered plate assembly interaction with a 0.50 AP M2 projectile.
DETAILED DESCRIPTION OF THE INVENTION
The inventors have performed testing and simulation studies examining the effect of projectile impact on armor surfaces and the projectile penetration into the armor.
Armor materials are arranged in various configurations to form systems that are intended to maximize projectile defeat for minimum areal density and volume. Arrangements are also dictated by the operational limitations of component materials. For example, ballistic-grade ceramics components are brittle and may experience catastrophic failure if subjected to what would be typical, safe, operational loads for the same components made from polymers or metals, e.g. ceramic body armor plates dropped to the ground by a wearer after being removed. U.S. Pat. No. 7,604,876 is an example of a solution intended to mitigate the fragility of ceramic armor components, and is also described in U.S. Pat. No. 6,408,734. Another example is the degradation of ballistic resistance of aramid fiber in damp environments due to the hygroscopic nature of the fiber.
There is a broad range of ballistic threats, and armor systems are most often designed to address a specific class of threat; more aggressive threats require heavier armor. Projectile threats have two primary forms: 1) bullets fired from small arms and machine guns, 2) fragments created by the explosion of metal cased ordnance. The nature and effectiveness of ballistic threats is generally a function of four projectile parameters: composition, mass, velocity, shape. Table 1 provides parameters for threats typically under consideration when evaluating armors intended for protection of military/police/infrastructure assets and personnel. FIG. 2 is a photograph showing three of the projectiles from Table 1.
There are numerous US Government standards that classify threats and armor protection levels, such as National Institute of Justice (NIJ) Standard 0108.01. The US Department of Defense (DoD) issues various specifications for ballistic protection of individual weapons, transport, and materiel systems, and individual body armor systems. These DOD standards are often unified with North Atlantic Treaty Organization Standards as Standardization Agreements (STANAG), e.g. STANAG 4241 Ed. 2 Bullet Impact, Munitions Test Procedures.
Threats of harder composition, higher mass, and higher velocity require heavier and/or more complex forms of armor. Long, slender bullet shaped projectile that impact tip first are more effective at defeating armor than shorter projectiles of the same mass, composition, and impact velocity. The ratio of projectile mass to the area of contact during impact is termed “sectional density.” All other parameters held equal, lower sectional density creates lower the pressures in an armor material, and thus less penetration results.
Bullet “ball” projectiles are composed of a copper alloy jacket, and lead filler that typically makes up more than 90% of the mass of the bullet. The relatively soft composition ball rounds tend to deform and expand when impacting armor. This expansion increase sectional density and may lead projectile breakup. Both changes result in less penetration potential for a given armor system.
Bullet “Armor Piercing” (AP) projectiles are composed of hardened metal cores such as hardened steel or tungsten carbide. FIG. 1A illustrates the composition and construction of a .50 caliber AP M2 bullet. The steel core for this bullet has a hardness of 63 on the Rockwell C scale. The resistance of the AP core deformation and/erosion hard core AP bullets is very effective in defeating various armor designs.
The inventors have performed testing and simulation studies examining the effect of projectile impact orientation relative to armor surface normal and the influence with regard to penetration into armor. There is particular influence for bullets as compared to fragment threats. Specific variables include the angle of projectile trajectory relative to the armor surface normal defined as “impact obliquity”, and the angle of the projectile long axis relative to the trajectory is defined as projectile “yaw”, see FIG. 1B .
Deviation from zero obliquity and zero yaw influences penetration in four primary ways: 1) sectional density affect, 2) tendency to deflect/redirect momentum, 3) increase in penetration path length, 4) tendency to induce yaw in the projectile. This fourth effect, induced yaw, can lead to bullet instability characterized by ever increasing yaw. Projectile sectional density is reduced as a yawing projectile penetrates armor, which leads to lower interface pressures and less penetration potential.
Evaluation of armor against ordnance fragment threats is typically accomplished using Fragment Simulating Projectiles (FSP) as surrogate for actual fragmenting metal bomb casings. FSPs enable consistent, controlled launch velocities and stable flight to achieve accurate hit points during armor testing. FSP relevant modern military armor systems are defined under DOD specification MIL-DTL-46593B and NATO STANAG 4496. Some of the defined fragment sizes and weights are shown in Table 1. Fragment threats, and by extension FSPs, differ from bullets in three key ways: 1) lower sectional density, 2) steel composition, 3) higher test velocities.
Compared to bullets, the lower sectional density of fragments is more than compensated for by higher impact energy. Due to relatively ductile steel composition, fragment deformation during armor penetration also differs from that of bullets. Fragments show some of the expansion, i.e. “mushrooming,” that lead core bullets exhibit.
TABLE 1
Ballistic threats for armor evaluation
Diameter
Overall Length
Mass
Velocity
Energy
Threat
Standard
(mm)
(mm)
(g)
Composition
(m/s)
(kJ)
.22 cal
DTL-
5.5
2.54
1.1
Steel, RHC 2
2530 4
3.5
FSP
46593B
30
.30 cal
DTL-
7.52
3.45
2.9
Steel, RHC 2
2530 4
9.1
FSP
46593B
30
.50 cal
DTL-
12.6
5.7
13.4
Steel, RHC 2
2530 4
43
FSP
46593B
30
20 mm
DTL-
20
22.9
53.8
Steel, RHC 2
2530 4
172.3
FSP
46593B
30
STANAG
4496
14.3
15.56
18.6
Steel, RHC 2
2530 4
59.6
14.3 mm
30
FSP
9 mm,
NIJ
9
15.5
8
Lead, FMJ 3
427
0.7
Ball
0108.01,
Bullet
Level II
7.62 mm
NIJ
7.62
32.5
9.7
Lead, FMJ 3
839
3.4
M59 Ball
0108.01,
Bullet
Level III
.30-06 AP 1
NIJ
7.62
35.6
10.8
Steel, RHC
869
4.1
M2 Bullet
0108.01,
63, FMJ 3
Level IV
.50 cal AP
STANAG
12.9
58.7
45.3
Steel, RHC
854
16.5
M2 Bullet
4241
63, FMJ 3
1 AP, Armor Piercing, characterized by a hardened steel core
2 RHC, Hardness on Rockwell C scale
3 FMJ, Full Metal Jacket, Jacket is typically a soft copper alloy
4 Gurney velocity limit for fragments formed by military high explosive
From these studies and the simulations described below, armor components have been developed which exhibit an enhanced capability to deflect and damage ballistic projectiles and threats as compared to conventional armor plates. Moreover, the armor components of the inventions (as compared to conventional armor) are lighter in weight. Indeed, one key design goal for armor is to minimize the mass of the armor per unit area of coverage, or areal density, e.g. 1b/ft 2 , and thus the burden on vehicles, aircraft, etc. The basic operational principle of these systems is to provide resistance that absorbs energy from projectiles and brings its momentum to zero within the armor assembly.
Moreover, the armor components of the invention can provide protections against a broad range of threat projectiles, and effectiveness against “armor piercing” projectiles are highly desired. According to the present invention, the armor components can exhibit improved tolerance to multiple impacts and overall robustness through the use of ductile materials. The armor of the present invention has applications in vehicle and aircraft armor, body armor and shields, shielding of buildings and materiel, containment of shrapnel, and other applications. The armor of the present invention is useful in a stand-alone capacity, or as an appliqué to augment existing armor systems.
In one embodiment of the invention, there is provided a serrated armor plate which is configured in size, depth of serration, width of serration, and material of the plate to deflect and damage ballistic projectiles upon entry. As shown in FIGS. 3 and 4 , the plate contains recessed lands and raised lands with columnar tapered projections extending from the recessed lands to form the raised lands.
In another embodiment of the invention, there is provided a louvered plate system which is configured in overall size, width of each louvered plate, angle of each louvered plate, and material of the plate to re-orient and damage ballistic projectiles upon entry. As shown in FIGS. 10 and 11 , the plates are flat, at a non-zero angle, and arranged in a series such that there is no open passage for a projectile having a flight path near 90 degrees, relative to the overall plate array.
A serrated surface armor component or a louvered plate armor component and configurations for employing either component in a protective armor system have been developed. The serrated surface or louvered plate system both act on projectiles in two advantageous ways:
1) Induce yaw and instability in high sectional density projectiles, e.g. armor piercing bullets; and 2) Create stress concentrations in impacting projectiles that result in projectile break up.
Advantages of each include:
1) Enhanced performance under multiple impacts (multi-hit); 2) Eliminating this use of brittle ceramics to produce pressures high enough to cause projectile fracture,
a. Reduced cost, and b. Increase multi-hit performance;
3) Effective against a broad range of threats, including lead and steel core bullets, AP bullets, and fragment; and 4) Effective as a retrofit to enhance existing armor systems.
The serrated component in one embodiment can be considered as a set of serrate “teeth” extending outward from a supporting surface. Serrate teeth may extend from one of both sides of a supporting surface. FIGS. 4 and 5 illustrate the design. The geometric serrated design in one embodiment of the invention is based on the following parameters, illustrated in FIG. 4 :
Y1, Overall component thickness
Y2, Tooth height
X1, Tooth pitch
X2, Gap width
Θ1 and Θ2, Tooth slopes
These parameters define the width and pitch of the lands, the taper angle of the columnar projections, and the thickness of the entire serrated plate and the base of the serrated plate. These parameters may be varied to maximized component effectiveness while minimizing areal density. Design variations may be driven by the nature of the ballistic threat, or threat set. The above parameters can be adapted to enable the serrated plates to function in a dual purpose role as both an armor protection component and also in carrying structural loads.
Tooth pitch, X1, and Tooth gap, X2, vary as a function of threat projectile diameter(s). Larger diameter threats and AP threats are given more weighting in determining these parameters. For instance, X1 and X2 are 13 mm and 10 mm, respectively, in a design solution where the most aggressive threats are .50 cal AP and 14.3 mm fragment.
Tooth taper angles Θ1 and Θ2 may individually range from 0° to 45°. Dissimilarity in Θ1 and Θ2 produces advantageous asymmetric forces on the projectile in the instances where it impact near one-half X2. Therefore, unequal Θ1 and Θ2 is the most desirable design. Development works shows that 0° Θ1 and Θ2 produces high induced yaw and projectile damage, but has a lower efficiency in terms of areal density.
As shown in FIG. 5 , there is provided in this invention a dual serrated armor plate configuration having a serration configuration provided on both sides of the armor plate. This configuration provides additional deflection capability and/or provides for additional resistance of the plate to the projectile.
FIG. 6 illustrates a specific single face serrated design. In this particular example, the serrated armor plate of the invention has been realized in a design made of a hardened steel alloy where X1 was 13 mm, X2 was 10 mm, Y1 was 6.4 mm, Y2 was 4.7 mm, Θ1 was 20 , and Θ2 was 0 . During the inventors' development of the armor of the invention, plates of this design were machined from 4130 alloy steel. Heat treat hardening to approximately 47 on a Rockwell C scale was done after machining.
In another particular example, the serrated armor plate of the invention has been realized in a design made of ANSI 4340 grade steel hardened to HRC 52, where X1 was 3 mm, X2 was 4.4 mm, Y1 was 7.6 mm, Y2 was 5.5 mm, Θ1 was 20 , and Θ2 was 0 .
In another particular example, the serrated armor plate of the invention has been realized in a design made of ANSI 4340 grade steel hardened to HRC 52, where X1 was 14.1 mm, X2 was 11.3 mm, Y1 was 9.5 mm, Y2 was 7.4 mm, Θ1 was 20 , and Θ2 was 0
In the case of the dual faced design, characterized by serrates on both sides of the base surface, the shape and orientation of the teeth may be the same or different on each side. The relative angle between the teeth ridges may range from 0° to 90°. Teeth on each side may be aligned or offset.
The louvered plate component can be considered as a series of flat angled plates in the armor system. FIGS. 10 and 11 illustrate the design. The geometric louvered plate design in one embodiment of the invention is based on the following parameters, illustrated in FIG. 11 :
w, Overall plate width
t. Overall plate thickness
Z1, plate pitch
Z2, plate overlap width
Θ3, plate angle
These parameters define the overall plate dimensions and the positioning of the plates. These parameters may be varied to maximize component effectiveness while minimizing areal density. Design variations may be driven by the nature of the ballistic threat, or threat set. The above parameters can be adapted to permit louvered plates to function in a dual purpose role as both an armor protection component and also in carrying structural loads.
Plate width and thickness, w and t, vary according to the severity of the threat, i.e. sufficient width and thickness is necessary to turn/break up the given projectile. Plate pitch and overlap width, Z1 and Z2, must be sized to ensure no gaps exist between plates, as viewed at 90 degrees to the overall array, and plates can withstand multiple threat impacts without tearing completely apart. Plate angle, Θ3, can be between 0 and 90 degrees, where most effectiveness is expected between 30 and 60 degrees.
In one embodiment, the louvered plates are anchored in place using lightweight, rigid support structure designed to localize threat damage and increase effectiveness against multiple projectiles impacting in series and in close proximity. FIGS. 12A and 12B show two specific support structure configurations. The specific application shown in FIG. 12A employs support structure including aluminum honeycomb core and fiberglass facesheets to encapsulate the plates. In this particular design, the plates are hardened AISI 4340 steel where w=2″, t=0.118″ and Θ3=45 degrees. The specific application shown in FIG. 12B employs support structure including stamped aluminum panels, foam core, and fiberglass facesheets to encapsulate the plates. In this particular design, the plates are AISI 4340 steel, hardened to 48 on a Rockwell C scale, where w=2″, t=0.118″ and Θ3=48 degrees.
In one embodiment of the invention, the serrated or louvered armor components of the invention may be comprised of materials appropriate for the identified ballistic threats, operating environment, and structural requirements. Appropriate metals may include steel, aluminum, titanium, beryllium, copper, and their alloys. Specific alloys include hardened AISI 4340 and 4130 steel, Ti-6AL-4V titanium (ASTM Grade 5), 7075-T6 aluminum, 7039-T64, 2195-BT aluminum, 2139-T8 aluminum. Serrated or louvered armor components made of these metals are relatively ductile compared to typical ceramic strike faces. Damage propagation is much lower in these metal solutions, relative to ceramics, thus armor performance is improved in multiple hit scenarios, e.g. .50 cal AP M2 “triple shot” evaluation described in STANAG 4241.
Composites comprised of fibers in a supporting matrix may also be used for serrated or louvered plate construction. Candidate fibers include glass, aramid, carbon, basalt, boron, polypropylene, and ultra high molecular weight polyethylene. Ceramics such as alumina, silicon carbide, boron carbide, titanium nitride, and titanium diboride might also be used to for all or part of the serrated or louvered armor component.
Appropriate processes for serrated plate fabrication are based on the material and geometry. Metal serrated plates might be machined or forged, with intermediate or post-process heat treatment as required. Large scale production of steel serrated plates can employ hot-rolling processes. For aluminum, components can be formed using extrusion. Composite serrated plate components might be formed using molds or pultrusion. Metal and/or ceramic components might be embedded in composite bulk geometries.
Serrate component plates may be curved, as illustrated in FIG. 7 , to provide conformation to protected assets. Serrate teeth may be straight or curved as illustrate in FIG. 7 . In one embodiment of the invention, the serrated plate of the armor assembly is formed into curved sections, as shown in FIG. 7 . The curved section provides additional strength to the serrated plate. The curved section provides additional projectile-resistance to the serrated plate. In one particular example, the serrated armor plate of the invention has been realized in a design made of 4340 steel, where X1 was 13 mm, X2 was 10 mm, Y1 was 6.4 mm, Y2 was 4.7 mm, Θ1 was 20 , and Θ2 was 0 and R (the radius of curvature) was 0.5 m.
In one embodiment of the invention, the serrated plate of the armor assembly is formed into conformal sections, as shown in FIG. 7 . Here, in this embodiment, the serrated plate can be made to conform around objects such as gun portals or sight windows to permit the armor not to interfere with the offensive utility of the vehicle being protected.
Because the individual plates in the louvered plate system are typically flat, the fabrication process focuses on plate arrangement and integration with support structure. Curved louvered plate systems can also be used in curved applications similar to those described for the serrate component as illustrated in FIG. 7 .
In one embodiment of the invention, the serrated or louvered plate components can be used in a system designed for a particular projectile (or range of projectiles) to maximize protection from the projectile threat. In one embodiment of the invention, the serrated or louvered plate components can be used to augment existing armor systems. In the case of existing systems, the serrated or louvered plates would be employed as an appliqué. One or more serrated plates our louvered plate systems can be applied. In this appliqué capacity, the serrated plate(s) or louvered plate system acts to initiate damage to a projectile, “pre-conditioning” the projectile, thus making the existing armor more effective and elevating the protection level of the overall system.
The attributes of the invention are more fully understood in light of the following non-limiting discussion of the function of the serrated plate of the armor assembly. FIG. 8 depicts results from a computer simulation of a hardened steel serrated plate interaction with a 0.50 AP M2 projectile entering at 2800 fps. In this simulation, the serrate armor plate was made of ANSI 4340 grade steel hardened to HRC 52, where X1 was 13.4 mm, X2 was 10.6 mm, Y1 was 7.6 mm, Y2 was 5.5 mm, Θ1 was 20 , and Θ2 was 0 .
As seen from FIG. 8 , the projectile upon entry on the recess land pierces the base of the serrated plate. With the pitch between lands being less than the width of the projectile, the sides of the projectile collide with the tapered columns and the raised lands. The interaction of the projectile with the tapered columns and the raised lands rotates the projectile such that more and more of the projectile must break through the serrated plate. Further, as the projectile progresses through the serrated plate under this rotation considerable drag resistance builds as the projectile now presents a larger areal projection to interact with the ruptured serrated plate. The net effect is to slow and turn the axis of the projectile such that its encounter with any material underneath the serrated plate is with reduced velocity and without the point of the projectile aligned on axis for penetration of the material underneath.
In one embodiment of the invention, one or more serrated plates can be used in an armor system. FIG. 9 illustrates this type of system. This system has been built and has been tested. This design uses the 4130 steel plates spaced approximately 2.5″ apart, and 2.5″ separation from a backing. The backing is a 1.25″ thick 7075-T6 aluminum. The tested assembly has a glass fiber/epoxy overwrap to provide environmental protection. The overall dimensions were 18″ on the sides and a thickness of less than 7″. In this arrangement, the serrated plates acted to induce yaw and to fragment a 0.50 AP M2 threat. While a significant part of the threat velocity is retained, the fractured and rotated pieces have a lower sectional density and disposed momentum. These affects allow the backing plate to arrest the threat, while incurring minimal damage.
Testing and computer simulations indicate that a system composed of two serrate steel plates and an aluminum back, and a system areal density of less than 38 pounds per square foot, can arrest a .50 caliber AP M2 projectile impacting with a velocity of approximately 2800 feet per second, and obliquity and yaw of less than 2 degrees.
FIG. 9 depicts more specifically results from a computer simulation of an armor system design using first and second single-side serrated plates and an underlying aluminum plate. This armor system design as noted above has been built and has been tested. The computer simulation shows the calculated projectile response. In this simulation, a 0.50 AP M2 projectile enters a first serration plate at 2800 fps. In this simulation, the first serrate armor plate was made of HHA steel, where X1 was 14.1 mm, X2 was 11.3 mm, Y1 was 9.5 mm, Y2 was 7.4 mm, Θ1 was 20 , and Θ2 was 0 . In this simulation, the second serrate armor plate was made of HHA steel, where X1 was 14.1 mm, X2 was 11.3 mm, Y1 was 9.5 mm, Y2 was 7.4 mm, Θ1 was 20 , and Θ2 was 0 . The second serrated plate is disposed such that its serrations are rotated with respect to the serrations of the first plate. In this simulation, the first and second plates have their respective serrations disposed rotated orthogonally. In this simulation, the projectile impact velocity is 854 m/s, 0° yaw and obliquity for a 0.50 AP M2 projectile.
As seen from FIG. 9 , the projectile upon penetration of the first serrated plate is slowed and rotated. The projectile upon penetration of the second serrated plate is further slowed and rotated. As shown in FIG. 9 , the projectile then impacts a ductile material such as aluminum where its kinetic energy is dissipated, and the projectile is stopped.
In one embodiment of the invention, as shown in FIG. 9 , the armor assembly includes a projectile receptor disposed underneath one or more serrated plates to stop the projectile. The projector receptor is made of a ductile component which provides resistance that absorbs energy from projectiles and brings its momentum to zero within the armor assembly, yet has a limited damage radius compared to ceramics. Specific alloys include hardened AISI 4340 and 4130 steel, Ti-6AL-4V titanium (ASTM Grade 5), 7075-T6 aluminum, 7039-T64, 2195-BT aluminum, 2139-T8 aluminum.
Similarly, FIG. 13 depicts results from a computer simulation of a hardened steel louvered plate system interaction with a 0.50 AP M2 projectile entering at 2800 fps. In this simulation, the louvered armor plate was made of ANSI 4340 grade steel hardened to HRC 52, where Z1 was 1.4″, Z2 was 0.25″, w was 2″, t was 0.118″, and Θ3 was 48 . The steel plates are held in place by a series of aluminum supports similar to that depicted in FIG. 12B . The backing plate, or projectile receptor, is located approximately 4″ from the bottom of the louvered plate system, including high hard armor (HHA) per Mil-A-46100, backed with composite laminate.
Moreover, in one embodiment of the invention, the serrated or louvered plates are also made of a ductile component. The advantages of ductility are significant in both the forward serrate or louvered components and the rearward catch panel (as noted above). Remarkably, a ductile serrated or louvered plate is as effective as ceramics in “breaking” hardened projectiles, but the ductile serrate or louvered plate is more robust than a ceramic. Ceramics tend to fracture catastrophically, with a failure radius many times the diameter of the impacting projectile. Effectiveness within this radius is severely reduced. On the other hand, a ductile serrated or louvered plate would have a much smaller damage radius, and this be less vulnerable to subsequent impacts.
Numerous modifications and variations of the invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | An armor and a system for projectile neutralization. The armor has at least one serrated plate or louvered plate system. The serrated plate has a base, recessed lands, raised lands, and columnar projections extending from the recessed lands to the raised lands to form serrations on the serrated plate. The louvered plate system has a series of angled plates, a base, a top and a support structure connecting the louvered plates with the base and the top. The system has a serrated or louvered armor plate configured to reduce a kinetic energy of the projectile and re-orient the projectile upon rupture through the armor plate, and has a projectile-receptor configured to capture the projectile after rupture through the armor plate. Projectiles which impact on the serrated or louvered plate system have a kinetic energy thereof reduced and become re-oriented upon rupture through the serrated or louvered plate system. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This U.S. patent application is the U.S. national phase, under 35 USC 371, of PCT/EP2005/051975, filed Apr. 29, 2005; published as WO 2005/108079 A1 on Nov. 17, 2005; and claiming priority to DE 10 2004 021 606.1, filed May 3, 2004, the disclosures of which are expressly incorporated herein by reference.
FIELD OF THE INVENTION
The present invention is directed to devices of a printing press having a rotation transmitter for introducing a liquid or gaseous medium into a rotating component of a printing press. The device includes a rotor, which is arranged to rotate with the rotating component of the printing press, and a stator that is secured against rotation. At least one channel section is provided in both of the stator and the rotor.
BACKGROUND OF THE INVENTION
Rotation transmitters are generally known, such as, for example, the devices which are disclosed in EP 0 570 786 B1 and in EP 0 544 815 B1. Rotation transmitters of this general type are typically used, though are by no means exclusively used, for transferring compressed air into a forme cylinder. Such a transference of compressed air is done to be able to, for example, actuate a clamping body for use in fastening the printing plates to the forme cylinder, by use of the compressed air. A plate clamping body of this type, that is appropriate for fixing a printing plate on the forme cylinder, is generally known from WO 02/43962 A2, for example.
US 2003/0172820 A1; EP 0 562 269 A, and DE 42 09 341 C2 each disclose a rotating introduction system for printing presses. The contact surfaces of the rotor and stator are arranged in the axial direction of the rotating introduction system.
SUMMARY OF THE INVENTION
The object of the present invention is to provide devices of a printing press having a rotation transmitter for use in introducing a liquid or gaseous medium into a rotating component of a printing press.
This object is attained, according to the present invention, by the provision of a rotation transmitter which has a rotor, that is arranged to rotate with the rotating printing press part, and a stator which is fixed against rotation. At least one channel is provided in each of the rotor and the stator. The liquid or gaseous medium is caused to flow through the stator channel, and through the rotor channel, when the two are aligned. The rotor channel and the stator channel each extend axially.
One advantage of the device with a rotation transmitter, in accordance with the present invention, is that a contact surface between the rotor and the stator, and the sealing joint resulting between them, may be sealed in a considerably easier fashion. In contrast to the generally-known rotation transmitters, in which the rotor and the stator come into contact with one another on cylindrical surfaces, the axial orientation of the rotation transmitter, in accordance with the present invention, allows for flat contact surfaces to be provided, which flat contact surfaces may be produced in a cost-effective manner and which may be sealed using simple sealing procedures.
The rotation transmitter in accordance with the present invention offers considerable advantages, especially when several different functional elements on the printing press part must be supplied with compressed air, although this supplying of compressed air must not necessarily occur on all of the functional elements at the same time. This is the case, such as, for example, when several printing plates are to be attached to one forme cylinder. The fastening of the various printing plates to the forme cylinder must not occur at the same time. By appropriately arranging or positioning the first channel sections in the stator in a circular array, around the rotational axis of the rotor, it is possible for the inlet openings, which are embodied, for example, in segments, of various second channel sections, to be selectively connected by rotating the forme cylinder against the first channel sections. In this manner, it is possible for a plurality of various functional elements to be actuated, using only a few control valves, with the various control valves being selectively connected to their respectively assigned functional elements by rotating the printing press part.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention is shown in the drawing and is described in greater detail below.
Shown are:
FIG. 1 a schematic side elevation view of a forme cylinder with a rotation transmitter in accordance with the present invention; in
FIG. 2 an enlarged cross-sectional view of a portion of the forme cylinder of FIG. 1 and showing the fixing device of the forme cylinder; in
FIG. 3 various possibilities for the pressurization of the fixing device of the forme cylinder in accordance with FIG. 1 in a first position; in
FIG. 4 a schematic view of a stator of the rotation transmitter on the forme cylinder in accordance with FIG. 1 ; in
FIG. 5 a schematic view of a rotor of the rotation transmitter in accordance with the present invention, on the forme cylinder in accordance with FIG. 3 , rotated by 180°; in
FIG. 6 a schematic, perspective depiction of a rotor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a schematic depiction of a forme cylinder 01 having a rotation transmitter 02 attached to a first end of the forme cylinder 01 and being usable for transmitting compressed air from a compressed air supply, which is not specifically shown, into the forme cylinder 01 . A total of eight printing plates 03 , 04 , 06 , 07 , 08 , 09 , 11 , and 12 may be attached to the circumference of the forme cylinder 01 . The printing plates 03 , 04 , 06 , and 07 , are arranged one next to the other in the axial direction on one side of the circumference of the forme cylinder 01 . The printing plates 08 , 09 , 11 , and 12 are arranged in a similar manner on the other side of the circumference of the forme cylinder 01 . The printing plates 03 and 08 are arranged one after the other, in a direction of rotation of the forme cylinder 01 , as are the printing plates 04 and 09 , the printing plates 06 and 11 , and the printing plates 07 and 12 . Instead of the depicted four printing plates being arranged next to one another in the axial direction of the forme cylinder 01 , it is naturally also possible for two, three, five, six, seven, or eight such printing plates to be arranged next to one another in the axial direction on a forme cylinder 01 .
Eight printing plate end fixing devices 13 , which may each be individually activated, are provided in the barrel of the forme cylinder 01 and are utilized for fixing or securing the respective printing plates 03 to 12 to the forme cylinder 01 . The structure and function of the fixing devices 13 will be explained below with reference to the depiction in FIG. 2 .
On its jacket or circumferential surface, the forme cylinder 01 has two diametrically spaced channels 14 , which are each pointing radially inwards and which are extending in the axial direction of the forme cylinder 01 . The beveled ends of two printing plates, which are arranged one after the other in the direction of rotation of the forme cylinder 01 , such as, for example, the beveled ends of the printing plates 03 and 08 , extend into the channel 14 . The diametrically opposite channel 14 , which is also provided in the forme cylinder 01 for fixing the other ends of both of the printing plates 03 and 08 , is embodied in a functionally complimentary fashion.
One beveled end of a printing plate, such as, for example, the beveled end of the printing plate 08 in FIG. 2 , is hooked into the channel 14 in a form-fitting manner. A clamping piece 16 , that is spring loaded by a spring 17 , is used to fix the other beveled end of another printing plate, such as, for example, the beveled end of the printing plate 03 in FIG. 2 . A pressure hose segment 18 is arranged between the clamping element 16 and a counter bearing 19 . This pressure hose segment 18 is provided for opening the clamping piece 16 . Channel sections 21 are usable to provide the various pressure hose segments 18 with compressed air. By increasing the pressure in the pressure hose segment 18 , it is possible for the clamping piece 16 to be pivoted against the spring force of the spring 17 . The result is that the beveled end of the printing plate 03 is released. The printing plate end fixing device 13 may also have several clamping pieces 16 , i.e., it may be constructed in several parts. Each such printing plate end fixing device 13 is to be understood to mean the entire fixing device 13 for one printing plate 03 , 04 , 06 , 07 , 08 , 09 , 11 , and 12 .
As can also be seen from FIG. 1 , an assigned pressure hose segment 18 is provided for each printing plate 03 to 12 . In one preferred embodiment, a total of eight different forme cylinder channel sections 21 are provided in the interior of the forme cylinder 01 , which forme cylinder channel sections 21 connect a rotor 22 of the rotation transmitter 02 to the various pressure hose segments 18 .
The rotor 22 is preferably in the shape of a circular disc, as may be seen in FIG. 6 . A pin of the forme cylinder 01 protrudes through the rotor 22 so that the rotor 22 of the rotation transmitter 02 rotates with the forme cylinder 01 .
A stator 23 of the rotation transmitter 02 which, for example, may be attached to the frame of a printing press in a rotationally secure manner is aligned with the rotor 22 of the rotation transmitter 02 , as seen in FIG. 1 . The stator 23 of the rotation transmitter 02 is connected to an air supply by the use of four first channel sections 24 , with a pressure regulator valve being provided in each such channel section 24 for regulating the pressure of the compressed air which is supplied to the stator 23 . The stator 23 of the rotation transmitter 02 is mounted in an axially displaceable fashion and is pushed away from the rotor 22 by a spring force provided by spaced plate springs 26 . To bring the stator 23 axially into contact with the rotor 22 , a pressure line 27 is loaded with compressed air such that the resulting air pressure pushes the stator 23 to the left in the axial direction and into contact with the rotor 22 of the rotation transmitter 02 .
FIG. 5 shows the four different pressure hose segments 18 and the manner in which they are provided with compressed air by the rotor 22 of the rotation transmitter 02 in a second position. The rotor 22 was rotated by approximately 180° with respect to the forme cylinder 01 .
In the top view of the contact surface 33 of the stator 23 , as shown in FIG. 4 , there is depicted the arrangement of the outlet openings 28 , 29 , 31 , and 32 into which the first channel sections 24 on the stator 23 empty.
In FIG. 3 , the actuation of the pressure hose segments 18 , when these pressure hose segments 18 are being pressurized, for opening the plate end fixing devices 13 for the printing plates 03 , 04 , 06 , and 07 , is shown by way of example. In the case of the forme cylinder 01 , the only printing plates that are removed are those with a plate end fixing device 13 that points or is facing upwards. None of the plate end fixing devices 13 that point downwards must be opened. Four different compressed air supplies, with their associated pressure regulation valves, which must be switched each time, are sufficient to actuate the eight different plate end fixing devices 13 which are situated on the forme cylinder 01 . To implement this economizing measure in a structural fashion, the outlet openings 28 and 29 as well as the outlet openings 31 and 32 are arranged on two different concentrically arranged circular lines around the rotational axis 34 of the forme cylinder 01 , as may be seen in FIGS. 3 and 5 .
Four arcuately-shaped, radially outwardly located compressed air inlet openings 36 , 37 , 38 , and 39 are formed on the rotor 22 and are assigned to the two compressed air outlet openings 28 and 29 that are arranged on an outer circular line. Four arcuately-shaped, radially inwardly located compressed air inlet openings 41 , 42 , 43 , and 44 are formed on the rotor 22 and are assigned to the two compressed air outlet openings 31 and 32 arranged on an inner circular line. By correspondingly rotating the rotor 22 , two of the outer, arcuately-shaped compressed air inlet openings 36 to 39 or two of the inner, arcuately-shaped compressed air inlet openings 41 to 44 may always be connected to the compressed air supply of the first channel segments 24 by the outlet openings 28 to 32 . The inlet openings 36 to 39 and 41 to 44 and/or the outlet openings 28 to 32 may have elastic sealing material or may be provided with an elastic seal as depicted in FIG. 6 with respect to the rotor 22 .
If, for example, the printing plates 03 , 04 , 06 , and 07 , which are all located on one circumferential side of the forme cylinder 01 , should be removed from the forme cylinder 01 , the forme cylinder 01 is rotated for a sufficient length of time so that the cylinder channel 14 points perpendicularly upwards. This position of the forme cylinder 01 corresponds to the position of the rotor 22 which is shown in FIG. 3 . In this position, the stator 23 , with its contact surface 33 , which is shown in FIG. 4 , is pressed, in a pressure-tight manner, against the contact surface of the rotor 22 such that compressed air may flow out of the outlet opening 28 of stator 23 , which is indicated in FIG. 3 into the inlet opening 36 of the rotor 22 , compressed air may flow out of the outlet opening 29 of stator 23 , which is indicated in FIG. 3 , into the inlet opening 37 of the rotor 22 , compressed air may flow out of the outlet opening 31 of stator 28 , which is indicated in FIG. 3 into the inlet opening 43 , and compressed air may flow out of the outlet opening 32 of stator 23 , which is indicated in FIG. 3 into the inlet opening 44 . In this position, the four other outlet openings 41 , 42 , 38 , and 39 on the rotor 22 are not connected to the compressed air supply.
If the four other pressure hose segments 18 are then to be connected to the compressed air supply, in order to be able to now actuate the plate end fixing devices 13 for the printing plate ends on the printing plates 08 , 09 , 11 , and 12 , the rotor 22 , together with the forme cylinder 01 , is rotated by approximately 180°. The rotor inlet openings 38 , 39 , 41 , and 42 on the compressed air supply are now connected to the stator outlet openings 28 , 29 , 31 , and 32 , whereas the rotor inlet openings 36 , 37 , 43 , and 44 are no longer being supplied with compressed air. Thus, by rotating the forme cylinder 01 through 180°, the compressed air supply is switched, as may be seen in FIG. 5 .
Because the inlet openings 36 to 44 are structured in the shape of an arc, the various, plate end fixing devices 13 may each be actuated in an angle range of approximately 60°, such that the rotor 22 does not have to be positioned absolutely precisely aligned relative to the stator 23 . It is also possible, for example, for the rotor to be rotated by −15° to +45′ when the stator 23 is engaged in order to allow a printing plate to be mounted or removed when the plate end fixing device 13 is open.
FIG. 6 shows a schematic, perspective depiction of the rotor 22 .
While a preferred embodiment of devices of a printing press having a rotation transmitter, for introducing a liquid or gaseous medium into a rotating component of a printing press, in accordance with the present invention has been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example, the source of the liquid or gaseous medium, the specific structure of the printing formes and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims. | A rotating element of a printing machine is connected to a rotation transmitter that is usable to introduce a liquid or a gaseous medium into the rotating element. The rotation transmitter includes a rotor that is rotatable with the rotating element, and a stator that is secured against rotation. At least one stator channel section cooperates with at least one rotor channel section to provide a fluid flow path for the medium into the rotating element. Axially oriented and mutually opposite contact surfaces, which are against one another when the liquid or gaseous medium is introduced into the rotating element of the printing machine, are provided on the rotor and on the stator. | 1 |
SUMMARY OF THE INVENTION
This invention relates generally to strip oiling systems for lubricating strip material prior to feeding of the material into a machine tool or the like, and deals more particularly with such a system wherein a distribution device is provided for distributing oil longitudinally of upper and lower rollers adapted to be turned as a result of the strip material being fed therebetween.
The general object of the present invention is to provide a strip oiling system capable of depositing films of oil on both the upper and lower surfaces of a continuously moving strip of metal or the like. Such a strip must be so lubricated prior to undergoing the forming process in most types of machine tools for forming articles from said strip material.
A more specific object of the present invention is to provide a device for distributing oil uniformly along the axis of an upper roller of such a system, and to thereby provide a uniform film of oil on the upper surface of the strip.
These objects, and others which will be apparent to those skilled in the art, are achieved in the system disclosed herein. In its presently preferred form the system comprises a continuous flow system which may be vacuum controlled to maintain a predetermined level of oil in an oil bath associated with a bottom roller, which serves to apply a uniform film of oil to the underside of the strip. The moving strip rotates the bottom roller, and also rotates a top roller which applies a similar oil film to the strip upper surface. A novel oil distributing device in the form of a tension spring oriented parallel to and above the axis of the upper roller can be stretched slightly to meter oil downwardly between its convolutions onto the upper roller. A supply of excess oil is continuously conveyed through the spring to the oil bath associated with the lower roller. The vacuum control system includes a first control chamber having an upper region at subatmospheric pressure above the surface of the oil in the chamber. A standpipe has its upper end in communication with said upper region and its lower end is in the oil bath to define the level of oil desired to be maintained therein. Means is also provided for replenishing oil drawn from the control chamber by the distribution device, through a trap or the like, and said replenishing means preferably comprises an inverted container and an associated supply line with a second standpipe in the control chamber. Oil is continuously available to replace oil withdrawn from the control chamber, and the level of oil in the control chamber is determined by the height of the lower end of said secondary supply standpipe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical elevational view with portions broken away illustrating an oil distributing device and associated oiler system incorporating the present invention.
FIG. 2 is a sectional view taken generally on the line 2--2 of FIG. 1 and also shows in schematic fashion the strip-like workpiece being unwound from a reel and passing through the device of the present invention prior to being fed into a machine tool or the like.
DETAILED DESCRIPTION
Turning now to the drawing in greater detail, FIG. 2 shows in schematic fashion a reel or coil of strip material, as indicated generally at 10, which strip material may comprise sheet metal or the like to be fabricated into articles of stamped or drawn configuration in a conventional machine tool, as indicated. In accordance with the present invention an oiler system is provided for applying a film of oil or other lubricant to both the upper and lower surfaces of the strip S as the strip is fed from the reel 10 to the machine tool.
The oiler system includes a generally open rectangular frame 14 through which the strip S of sheet metal or the like is adapted to be fed, and the motion of the strip S serves to rotate an upper roller 16 in a counterclockwise direction as indicated generally by the arrow in FIG. 2, and to rotate a lower roller 18 in the opposite direction or clockwise direction as indicated in FIG. 2. The lower roller 18 turns in an oil bath, indicated generally at 20, which oil bath serves as a sump for the excess fluid delivered to the upper roller 16 by the novel oil distribution device housed in the upper portion of the rectangular frame 14 and described in greater detail hereinbelow. The oil bath 20 is contained in a channel-shaped member 22 comprising the lower portion of the rectangular frame 14. The end walls of the sump for the oil bath 20 are defined by the vertical members 24 and 26. These vertical members 24 and 26 cooperate with channel-shaped elements 28 and 30, and more particularly with flanges thereof, said flanges being welded to the end members 24 and 26 respectively, to define an upwardly open box-like structure the inner walls of which define vertically elongated slots 32 best shown in FIG. 2 such that axle portions 34 and 36, of the upper and lower rolls 16 and 18 respectively, can be rotatably supported therein. These rollers 16 and 18 preferably include bushings 38,38 on these axles 34 and 36 such that the bushings are received in the said slots 32,32 and the axles 34 and 36 are rotatably received in these bushings.
Each of the rollers, 16 and 18, is of identical construction and includes a central core 40 attached to its associated axle, 34 and 36 respectively, and a plurality of annular pads 42,42 are mounted on the cores 40,40 to provide oil absorbent rollers such that the oil can be effectively picked-up from the sump or oil bath 20 associated with the lower roller 18 for example, and applied to the under surface of the strip S, and so that oil dripped downwardly onto the upper roller 16 can be similarly applied to the upper surface of the strip S as these rollers are rotated in response to translation of the strip.
In order to provide for sufficient frictional contact between the rollers and the strip a tension spring 44 acts between the axles 34 and 36 associated with the upper and lower rollers, 16 and 18, in order to urge these rollers toward one another. Thus, the rollers can accommodate strips of various thickness without the need for adjustments having to be made to the apparatus in the event of setting up the machine tool to accommodate strips of different thicknesses. The rollers 16 and 18 are supported in the same way at both their respective ends as best shown in FIG. 1, similar parts being denoted by similar reference numerals.
The generally rectangular frame 14 also includes an upper channel-shaped member 46 having depending channel leg portions 46a and 46b loosely received or otherwise attached to the leg portions of the upright channel members 28 and 30 associated with the sides of the rectangular frame 14. The flanges 29,29 of channels 28 and 30 are preferably provided with upper edges for supporting the web of the channel 46. Such configuration permits the removal of the upper channel member 46, and the associated oil distributing device to be described, with the result that the apparatus of the present invention can be conveniently cleaned or otherwise repaired with a minimum downtime.
Turning now to a more detailed description of the device for distributing oil in a uniform manner longitudinally of the upper roller 16, said device comprises a coil type tension spring 50 having its convolutions normally adjacent one another. The spring 50 is so mounted in the frame 14 such that it can be stretched in order to provide spaces between the adjacent convolutions in order to drip oil downwardly onto the upper roller 16 located therebeneath at a rate which can be controller to maintain a particular desired rate of flow. The oil may be dripped directly onto the roller or a wick device 12 may be provided to avoid any tendency for a low viscosity oil to splash when dripped directly onto the upper roller 16. Thus, the wick 12 or the roller 16 can be considered to be a lubricant applying means of elongated configuration.
The oil distribution device includes means for bypassing excess oil to the sump 20, and said means for bypassing such oil comprises the passageway defined by the internal cavity within the tension spring 50 such that oil may be continually bypassed to flow through the spring and out through the open left hand end as viewed in FIG. 1, with the result that the excess oil is dumped downwardly into the sump 20 referred to above. Means is provided for supplying oil to the distribution device, and said means includes supply means and a means for feeding oil at a rate which can be varied but which rate will always be in excess of the oil distributed to the upper roller 16.
Still with reference to the oil distribution device associated with the upper roller 16, it will be apparent that the tension spring 50 has its longitudinal axis above and substantially parallel to the axis of rotation of the upper roller 16. The spring 50 is supported at its right hand end by a collar 52 clamped to the spring, and a support rod 54 has an upturned right hand end portion 56 which is nonrotatably received in an opening in said collar 52 and has a threaded end for receiving a nut 58. The rod 54 passes through the interior passageway defined by the spring 50, and has a threaded left hand end portion 55 adapted to receive a nut 60 such that the left hand end portion of the rod can be secured to the channel-shaped support member 46, and more particularly to a depending web 46a provided for this purpose in the channel 46.
Means is provided for stretching the left hand end of the spring so that the clearance between at least some of its convolutions can be increased to thereby increase the rate at which oil is dripped onto the upper roller 16 and hence to the strip S, or workpiece therebelow. Preferably, said spring supporting means comprises the above-mentioned rod 54 and also a spring clamping collar 62, which collar is secured to the left hand end portion of the spring 50, but which collar is slidably received in the fixed frame 14 so as to be movable longitudinally with respect to the rod. It is a feature of the present invention that means is provided for adjustably positioning the movable collar 62 in a predetermined position in order to maintain a desired rate of flow of the oil downwardly onto the upper roller 16. Preferably, the means for movably or adjustably supporting the collar 62 comprises a lead screw 64 rotatably supported in the depending web 46a and having an end portion threadably received in an opening 62a in the collar 62. In order to prevent rotation of the collar 62, an upwardly projecting pin 62b is provided in the collar 62 and is slidably received in a longitudinally elongated slot 46c provided for this purpose in the upper frame member 46.
The right hand end portion of the oil distribution device communicates directly with an elbow 70 associated with the oil supply means to be described in order to admit oil to the right hand end of the spring 50 such that oil flows through the center portion of the spring and is bypassed in order to provide oil to the sump 20. A desired rate of flow of some of said oil is provided for downwardly through the spring convolutions depending upon the adjustment made by the lead screw 64.
Turning now to a more detailed description of the oil supply means for the distributing device, which device not only distributes oil to the upper roller 16 but also bypasses oil to the sump 20 associated with the lower roll 18, the oil supply means of the present invention includes means for maintaining the level of oil in the sump 20. Said means for maintaining the level of oil in the sump includes a standpipe 72 having its lower end 72a at the desired height for the liquid in the sump, and a closed control chamber 74 having a head space 76 at subatmospheric pressure above the surface of the oil in the chamber, which head space 76 communicates with the upper end 72b of the standpipe 72. Oil is provided to the elbow 70 associated with the right hand end of the distributing device through a short intermediate pipe 78 having its lower end connected directly to the elbow 70 and having its upper end defining a portion of a trap defining structure, the inlet of which trap is arranged inside the control chamber 74 and the outlet of which trap comprises the pipe 78. A second strandpipe 80 is provided with its lower end at a desired oil level in the control chamber, and a conventionally operated vacuum type reservoir means indicated generally at 82 has a connecting line 84 which serves to provide a continuous source of oil to the control chamber 74. The supply means 82 merely comprises an inverted jug of oil, and this jug functions in the manner of the conventional office water cooler. Air is bubbled up through the oil to replace the oil withdrawn through standpipe 84, providing a very simple and uncomplicated source of oil for the control chamber 74. The trap defining structure associated with the control chamber 74 comprises a flow restricting passageway 86 defined by an inverted channel-shaped member 88 associated with the upper end of the pipe 78 such that a relatively small cross sectional area of flow for the viscous oil is provided between the outer wall of the pipe 78 and the downturned right hand flange of the channel member 88. This trap defining structure assures that oil is provided at a sufficient rate to accommodate the oil distributed by the device which includes the tension spring 50, and also that oil is bypassed through the spring to the lower sump 20 in order to maintain the level of fluid in the sump 20 as dictated by the position of the lower end of the standpipe 72.
From the foregoing description it will be apparent that oil can be applied to only the lower surface of the strip simply by adjusting the tension spring 50 to fully closed position for bypassing all oil and feeding such oil to the sump 20. Not quite so apparent is the fact that oil can also be provided to only the upper surface of the strip S. Some oil would have to be continually bled from the sump 20, in order to accomplish this result, but merely providing a controllable leak in the sump would permit this result to be quite readily achieved. In such a system one might also want to provide a back-up roller for the underside of the sheet against which the upper roller 16 could act.
The upper roller, or lubricant applying means 16 may receive oil directly from the opening between the convolutions of the tension spring 50, or the wick device 12 provided with one end encircling the spring and the other end tangentially engaging the roller 16 to reduce splashing of the oil. The wick device 12 could be employed without the roller 16 to apply oil directly to the workpiece or strip S within the scope of the present invention. | A strip of sheet metal moves horizontally between upper and lower felt rollers, turning them in opposite directions so that the lower roller continuously picks up oil from an oil bath. Oil is dripped down onto the upper roller from a device which is continuously provided with oil from a reservoir. The distribution device provides for an excess of oil to be bypassed and deposited into the oil bath below, and the level of the oil in the bath is used to control the flow of oil to the distribution device. The device comprises a tension spring so supported above the upper roll that oil from the reservoir flows into one end, and depending upon the spacing between the spring convolutions, a portion flows out through these convolutions, and the remainder is bypassed through the other end into the oil bath. A uniform distribution of oil along the axial extent of the upper roller is made possible by the spring type distribution device. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to vehicle suspensions in general, and more particularly to an arrangement for regulating the level and inclination of a vehicle.
There are already known various constructions of level and inclination regulating arrangements for vehicles. An arrangement of this type usually includes at least two pneumatic or hydropneumatic resilient elements each of which is associated with a different wheel of an axle or a side of the vehicle. The resilient elements include a movable separating piston which is loaded on its one side by the wheel load and on its other side by a supporting pressure of a gas cushion which is confined in a housing and supports the separating piston.
Resilient elements of this type render it possible to achieve level and inclination regulation of the vehicle by adjusting the oil quantity or the gas amount to a static change in the wheel load during the loading and unloading of the vehicle, and to a quasi-static change render the wheel loading in driving conditions which are influenced by mass forces during the negotiation of curves or during breaking or acceleration.
In a known hydraulic-pneumatic resilient arrangement of this type, which is disclosed in the published German patent application No. DE-AS 11 22 286, a level and an inclination regulation for a four-wheel vehicle is achieved by using three level regulating devices arranged between the wheels and the superstructure. Such regulating arrangements influence the oil quantity by adding oil to or removing oil from the oil quantity. The resilient arrangement further includes four filling regulators each of which is connected with a separating piston and which are operative for displacing the separating pistons back toward a central position by adding or removing gas. Both the oil quantity and the gas amount are variable and, therefore, the expense incurred in constructing the position regulating arrangement of this type is disadvantageously high.
There is also known, from the published German patent application No. DE-OS 34 27 902, a regulating arrangement of the above-mentioned type with a fitting adjustment of the gas amount, in which position regulating elements are provided which are respectively associated with the individual ones of the resilient elements and which detect the position of a separating piston with respect to a desired position and, when a deviation from such a desired position is encountered and detected, cause gas to be discharged from the resilient element through a discharge conduit into a low-pressure accumulator, or cause gas to be supplied to the respective resilient element through a supply conduit from a high-pressure accumulator which is being charged with relatively high pressurized gas by a compressor which withdraws the gas from the low-pressure accumulator.
In addition thereto, there are provided, for a resilient group including two resilient elements which provide a supporting moment in driving conditions that are influenced by mass forces, respective devices which effect direct gas flow from the gas cushion of that one of the resilient elements which is extended into the gas cushion of the other resilient element which is retracted, wherein the connections of the discharge conduits to the low-pressure accumulator and of the supply conduits to the high-pressure accumulator are closeable. A multitude of auxiliary means in the form of two gas accumulators, two compressors and a plurality of regulating elements in the discharge and supply conduits are required in this construction, in a very expensive manner, for the achievement of the level of inclination regulation.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art.
More particularly, it is an object to the present invention to provide a level and inclination arrangement for vehicles, which does not possess the drawbacks of the known arrangements of this type.
Still another object of the present invention is to devise an arrangement of the type here under consideration which is significantly simplified in its construction relative to those of the prior art.
It is yet another object of the present invention to design the above arrangement in such a manner as to achieve highly accurate and properly sensitive vehicle level or inclination adjustment, despite the simplified construction of the arrangement.
A concomitant object of the present invention is to construct the arrangement of the above type to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet reliable in operation.
In keeping with these objects and others which will become apparent hereafter, one feature of the present invention resides in a level and inclination regulating arrangement for a vehicle which comprises a compressor having an inlet chamber and an outlet chamber; at least two pneumatic or hydropneumatic resilient elements each associated with one wheel of an axle of the vehicle and including a movable separating piston which is acted upon at one side by the wheel load, and a housing confining a gas cushion which exerts pneumatic pressure on and supports the separating piston at the other side; supply and discharge conduit means connecting each of the gas cushions with the outlet chamber and with the inlet chamber of the compressor, respectively; at least one accumulator incorporated into at least one of the supply and discharge conduit means as a separate branch thereof which communicates with the respective one of the outlet and inlet chambers; position regulating elements respectively associated with the resilient elements and operative for detecting the position of the separating piston with respect to a desired position and for controlling the discharge of gas from the respective gas cushion into the discharge conduit means and the supply of gas from the supply conduit means into the respective gas cushion in dependence on the deviation of the respective separating piston from the desired position thereof; and control valve means for selectively including the accumulator into and excluding the same from the connection through the one of the supply and discharge conduit means.
Advantageously, the accumulator is a low-pressure accumulator and is incorporated in the discharge conduit means; and a static level regulation takes place when the control valve means connects the gas volume of the low-pressure accumulator, while the compressor directly transfers gas from the gas cushion of that of the resilient elements which is extended into the gas cushion of the other of the resilient elements that is retracted when the control valve means disconnects the gas volume of the low-pressure accumulator for an immediate compensation for a lateral inclination during dynamic driving movements. According to another aspect of the present invention, the accumulator is a high-pressure accumulator and is incorporated in the supply conduit means, and a static level regulation takes place when the control valve means connects the gas volume of the high-pressure accumulator, while the compressor directly transfers gas from the gas cushion of that of the resilient elements which is extended into the gas cushion of the other of the resilient elements that is retracted when the control valve means disconnects the gas volume of the high-presssure accumulator for an immediate compensation for a lateral inclination during dynamic driving movements. It is, however, particularly advantageous when the control valve means includes first and second control valves for selectively incorporating the accumulator into the supply and discharge conduit means, respectively, to serve as one of a low-pressure and a high-pressure accumulator, and when a static level regulation takes place when the pressure in the accumulator is lower than that in the respective resilient element with the first control valve being open and the second control valve being closed, and when the pressure in the accumulator is higher than that in the respective resilient element with the first control valve being closed and the second control valve being open, while the compressor directly transfers gas from the gas cushion of that of the resilient elements which is extended into the gas cushion of the other of the resilient elements that is retracted when both of the first and second control valves disconnect the gas volume of the accumulator for an immediate compensation for a lateral inclination during dynamic driving movements.
It is advantageous in this context when both of the first and second control valves are open for load equalization; and when there are further provided additional valve means in at least one of the supply and discharge conduit; means for automatically closing off gas flow through the first control valve when the pressure in the accumulator exceeds that in the resilient element, in response to such reduced pressure in the resilient element, and through the second control valve when the pressure in the accumulator is below that in the resilient element, in response to such increased pressure in the resilient element. Advantageously, the position regulating elements are constituted by self-positioning control slides that are connected with the respective separating piston. It is also advantageous when each of the resilient elements includes a cylinder and a piston movable in the cylinder, and abutments which delimit the extent of displacement of the piston of the resilient element to an effective range, and when the resilient elements fully support the vehicle superstructure and stabilize the same during driving conditions which are influenced by mass forces.
According to another advantageous concept of the present invention, there is provided a level adjustment device which is selectively switchable on and off, while the compressor transfers gas directly from the gas cushion of that of the resilient elements which is extended into the gas cushion of the other of the resilient elements that is retracted when the control valve means disconnects the gas volume of the accumulator for an immediate compensation for a lateral inclination during dynamic driving movements, independently of the operation of the level adjustment device but when the level adjustment device is shut off.
What is common to all of the constructions according to the present invention is that, when the compressor function is switched on and a passage through the control valve means is opens, there is obtained an adjustment of the gas amount in the gas cushions of the resilient elements to a reduced carried load by supplying gas from a gas accumulator either directly or through the compressor, and an adjustment of the gas amount in the gas cushions of the resilient elements to an increased carried load by discharging gas into a gas accumulator either directly or through the compressor, until there is achieved the desired position of the separating pistons and a so-called level volume in the gas cushions. When the accumulator is selectively useable as a low-pressure and a high-pressure accumulator, one of the control valves of the control valve means must be closed while the other is open, in dependence on the loading condition of the gas in the respective gas cushion. However, both of these control valves can be open when it is assured that, when the pressure in the gas accumulator exceeds that in the respective gas cushions, the first connecting means is closeable by means of additional blocking means which is responsive to excess pressure and, when the pressure in the gas accumulator is below that in the respective gas cushions, the second connecting means is closeable by means of additional blocking means which is responsive to lowered pressure.
After the performance of the level adjustment in the above-discussed manner, the control valves are advantageously closed, and an inclination regulation can be accomplished in the following manner.
In the two resilient elements which constitute a resilient group, the separating piston of the resilient element which is extended is displaced out of the desired position and the separating piston of the resilient element which is retracted is displaced into the gas cushion by the driving conditions influenced by the mass forces, wherein the gas amount in the extended resilient element deviates by the amount of the outward displacement volume and the gas amount in the retracted resilient element deviates by the amount of the inward displacement volume from the level amount. When the compressor function is switched on, the position regulating elements, which detect the position of the separating piston or the gas cushion volume in any known manner, connect the discharge conduit of the extended resilient element through the inlet chamber and the outlet chamber of the compressor with the supply conduit of the retracted resilient element. As a result, there can take place, with the aid of the compressor, gas transfer from the extended to the retracted resilient element, wherein the gas volume of the extended resilient element is reduced in the direction toward the level volume, and the gas cushion of the retracted resilient element increases in the direction toward the level volume. It is a characteristic feature of the present invention that, given the same level volumes in both of the resilient elements and isothermal condition changes of the gas, the level volume is simultaneously obtained again in both of the resilient elements as soon as there is transferred a gas amount which is determined by the pressure reduction in the previously extended resilient element, the corresponding pressure increase in the previously retracted resilient element, and the amount of the level volume. This amount of gas will be designated here as a trimming amount. However, even if the change instate is Polytropic, the level volume will be achieved in each of the resilient elements substantially simultaneously, as soon as the trimming amount is transferred.
The gas transfer from the extended into the retracted resilient element can be achieved with a low energy consumption and so quickly that the superstructure remains practically parallel to the roadway even if the vehicle is subjected to conditions which are influenced by mass forces.
After the termination of the above-mentioned driving condition, there occurs during travel in a straight course a return flow of the trimming amount from the previously retracted resilient element into the previously extended resilient element, so that the level volume is again achieved in both of the resilient elements.
When resilient elements at the two sides of a vehicle axle form a resilient group, it is possible to achieve, by using the above-mentioned gas transfer, a righting of the superstructure up to the level position, that is, generally, parallel to the roadway, so that the same inward and outward displacement strokes are available while driving through a curve as during travel along a straight course. In this manner, therefore, the driving safety and driving comfort can be improved in an advantageous way.
It can be proven that the compressor output is so small that its contribution to the energy consumption of a motor vehicle is to b taken into consideration only in terms of a minute percentage proportion. The energy consumed by the compressor has only a negligible impact on the fuel consumption, inasmuch as the operation of the compressor occurs during the travel on relatively straight roads only at considerably spaced time intervals. The compressor work can be reduced when the drive of the compressor is provided with means which accepts and releases energy, for instance, in the form of a gyrating mass which stores energy during backflow of the gas and releases energy during the gas transfer.
When more than two of the resilient elements are combined into a resilient group, for instance, in a four-wheel vehicle which is fully equipped with a resilient arrangement according to the present invention, the outlet conduits of all of the resilient elements scan be commonly connected to the outlet chamber, while the inlet conduits of the resilient elements can be commonly connected to the inlet chamber of the compressor, and connecting conduits to the aforementioned gas accumulator may be provided and equipped with closing valve devices. Then, in all driving conditions which are influenced by mass forces, that is, during the driving through curves as well as during acceleration or deceleration, the superstructure can be righted in the above-discussed manner up to the position in which it is parallel to the roadway, or can be maintained parallel thereto, in that the trimming amount which is required in each instance is withdrawn from the extended resilient elements and is transferred into the retracted resilient elements, or it flows back, all of this happening when the closing devices are closed.
Actually, the gas transfer and the gas back flow could also take place during the above-mentioned driving conditions even if the closing devices were open. However, a constant gas exchange with the gas container would be connected with this expedient, and this is not desired and would require much more compressor output than the operation with the closing devices assuming their closed states.
When the separating pistons of all of the resilient elements have reached their desired positions and no trimming gas amount is needed, the compressor, which in this case would be equipped with a correspondingly large idle space which limits the compression ratio, could also operate constantly. Even other means which are known from the compressor design and construction field could be provided for the purpose of an interrupted gas flow when the compressor is running.
Inasmuch as the required trimming amounts are relatively small and the resistance coefficients of a gas flow are in any event rather low, the discharge and supply conduits may be made with relatively small inner diameters, for instance, in passenger cars, with diameters substantially corresponding to those usually employed in the conventional brake lines of a hydraulic brake facility.
In an advantageous manner, it is possible, in a fully loaded application of the present invention for an axle or for all axles or wheels of the vehicle, to dispense with other currently customary resilient stabilizing means which become effective mainly in curves or during acceleration or deceleration of the vehicle, for instance, in the form of torsion bars, when no or only a negligible tilting of the superstructure takes place in vehicles of this type due to the correspondingly rapid transfer and return flow of the trimming amount of gas. It is further advantageous that, in this manner, there can be avoided the hardening of the individual wheel suspensions by such stabilizing resilient means.
When a distribution of the superstructure weight takes place in a motor vehicle equipped with more than three wheels, for instance, with four wheels, to four fully loaded hydropneumatic resilient elements and all of the resilient elements are provided independently of one another with a level regulator each, there can occur a dangerous equilibrium condition in which two resilient elements which are situated diagonally oppositely to one another would carry the superstructure by themselves or almost by themselves and the wheels which are associated with the two other resilient elements would have no or only a small degree of roadway surface adherence. This driving condition is eliminated in the known hydropneumatic fully loaded suspensions mostly in such a manner that two resilient elements of one axle are connected with one another on the oil side and only three elevation regulators are being used. In the regulating arrangement according to the present invention, the gas cushions of the individual resilient elements are connected with one another from time to time during oscillations of the superstructure, so that the above-mentioned equilibrium situation, which is connected with the loss of the roadway surface adhesion, cannot occur. Rather, an optimum distribution of the superstructure weight to all four wheels is automatically adjusted in an advantageous manner with the respective center of gravity location, in that pressure differences in the gas cushions of the resilient elements are equalized up to the smallest possible pressure difference, wherein one of the resilient elements always reaches the level volume last.
When the wheel loads of the associated resilient elements are very different, for instance, those of the front axle and those of the rear axle, or also for different reasons the piston surfaces which carry the wheel load and are reduced to the wheel, are chosen to have different sizes, even the level volumes are advantageously chosen to be proportional to the piston surfaces, inasmuch as the trimming amounts of such resilient elements have the same magnitude in this case.
During concurrent vehicle movement, for instance, even during dipping or pitching or wobbling oscillations, a direct gas exchange is possible due to the presence and action of the position regulating elements between the gas cushions of simultaneously outwardly or inwardly moving resilient elements having different pressures, as a result of which there could occur undesirable wheel load changes. In order to avoid this, check valves can be interposed between the discharge conduits and the inlet chamber of the compressor, these check valves opening toward the inlet chamber, and/or between the supply conduits and the outlet chamber of the compressor, such check valves then closing in the direction toward the outlet chamber.
The check valves arranged upstream of the inlet chamber thus prevent gas exchange between simultaneously extended resilient elements, and the check valves arranged upstream of the outlet chamber thus prevent gas exchange between simultaneously retracting resilient elements.
When it is required, in a vehicle with a suspension according to the present invention for four or more wheels, that the wheel loads of two or more resilient elements have the same magnitude, there can be provided connecting conduits between the supply conduits or between the discharge conduits. A a result of this expedient, a gas exchange takes place during each inward or outward displacement of the associated resilient elements and established equal wheel loads. When this operation is to be performed with a delay, the connecting conduits can be provided with respective throttling devices. In an arrangement of these connecting conduits, there is maintained the stabilizing effect that the compressor transfers gas from the outwardly displaced into the inwardly displaced resilient elements for compensation of vehicle tilting. The same wheel loads can also be achieved when the check valves are omitted or are provided with throttling openings, for instance, in the form of leakage gaps.
Further details, explanations and exemplary numerical values, especially also for proving the small compressor output required, which are not required for the understanding of the present invention, can be ascertained from the German patent application No. DE-OS No. 36 04 068 which, published on Aug. 13, 1987.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described below in more detail with reference to the accompanying drawings in which:
FIG. 1 is a somewhat diagrammatic partially sectioned front side elevational view of a resilient group including two resilient elements which are associated with a low-pressure accumulator, with separating pistons in their desired positions.
FIG. 2 is a view similar to FIG. 1 but only of a fragment of the resilient group and with the separating pistons retracted due to an increased load an a closing device shown open;
FIG. 3 is a view similar to FIG. 2 but with the separating pistons extended due to a reduced load;
FIG. 4 is a view similar to FIG. 3 but with one of the separating pistons retracted and the other extended due to driving conditions influenced by mass forces, and with the closing device closed;
FIG. 5 is a view similar to FIG. 1 but having resilient elements of modified constructions, which cooperate with an accumulator of an arbitrary pressure, the accumulator acting as a low-pressure accumulator in this instance;
FIG. 6 is a view similar to FIG. 5 but only of a fragment threre of and with the separating pistons extended, the accumulator acting as a high-pressure accumulator in this instance; and
FIG. 7 is a partially sectioned developed view of an arrangement of the present invention including position regulating elements and check valves in on inlet chamber and in on outlet chamber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail, and first to FIGS. 1 to 6 thereof, it may be seen that they depict two resilient elements or units of a resilient group. These resilient elements are to be considered as left and right resilient elements of a vehicle axle. The same reference numerals have been used to identify the corresponding parts on the left and on the right. Unless necessary for better understanding of the construction, the reference numerals have not been duplicated. On the other hand, when it is required to differentiate between the corresponding parts, then the reference numeral identifying the respective part on the right side of the arrangement is supplemented with a prime, while the one on the left side of the arrangement is not.
A resilient group according to FIG. 1 is provided with two hydro-pneumatic resilient elements or units 101 and 101'. The resilient elements 101 and 101' are provided with respective connecting locations in the form of connecting pins 114 and 115. Each of the resilient elements 101 and 101' is provided with an oil quantity 103 which is confined in a working cylinder 102. A working piston 104 is slidingly received in the working cylinder 102, passes to the exterior of the working cylinder 102 through a cylinder lid 109 which is provided with a seal 108, and is operative for displacing oil out of the interior of the working cylinder 102. Each of the resilient elements 101 and 101' is further provided at a side thereof which is opposite to the respective working piston 104 or 104' with a respective gas cushion 107 and 107'. The gas cushion 107 or 107' is sealing separated from the oil quantity 103 by a separating piston 105 and is confined in a housing 106 which includes an outer wall 119. The housing 106 receives the oil which is displaced by the working piston 104 out of the working cylinder 102. The oil quantity 103 is subdivided into two parts by a partitioning wall 150 which is provided with throttling orifices 154 that serve for oscillation damping.
Each of the resilient elements 101 and 101' further includes a position regulating element in the form of a control slide 121 which is held on the separating piton 105 by means of a control rod 140 and which is slidingly displaceable with respect to a control sleeve 122 which is located within the connecting pin 114 that is connected with the outer wall 119. The control sleeve 122 is provided with an upper control opening 124 which communicates with a discharge conduit 112 or 112', and with a lower control opening 125 which communicates with a supply conduit 113 or 113'. The control sleeve 122 has a free space 157 situated upwardly of the control slide 121 and connected with the gas cushion 107 or 107' by a channel 156 provided in the control rod 140.
The discharge conduits 112 and 112' of the two resilient elements 101 and 101' are commonly connected with an inlet chamber 126 of a compressor 116, and the supply conduits 113 and 113' are commonly connected with an outlet chamber 127 of the compressor 116. The compressor 116 includes an inlet valve 135, an outlet valve 136 and a compression chamber 137. A low-pressure accumulator 110 is connected with the inlet chamber 126 of the compressor 116 through a connecting conduit 138 which is provided with a closing arrangement in the form of a turnable slide 117. The turnable slide 117 includes an open passage. In FIG. 1, the separating pistons 105 at the right and at the left are in their desired positions, in which both of the control openings 124 and 125 are closed by the control slide 121, so that no gas exchange is possible between the respective gas cushions 107 or 107' and the low-pressure accumulator 110.
When, as shown in FIG. 2 of the drawings in which reference numbers raised by 100 relative to those used in FIG. 1 are being used to identify corresponding parts, the separating pistons 205 and 205' are resiliently displaced inwardly or upwardly as shown, the lower control openings 225 and 225' are uncovered by the control slides 221, and there exists a connection of the gas cushions 207 and 207' of the two resilient elements 201 and 201' through the supply conduits 213 and 213' the outlet chamber 227, the outlet valve 236, the compression space 237, the inlet valve 235, the inlet chamber 226 and the then open turnable slide 217 with the low pressure accumulator 210. When the compressor 216 is in operation, the outlet chamber 227 serves as a gas source and there can occur a return displacement of the separating pistons 205 and 205' into their desired positions shown in FIG. 1 of the drawings in any arbitrary succession, and a level regulation by an increase of the gas amounts in the gas cushions 207 and 207'.
When, as shown in FIG. 3 of the drawings in which reference numbers raised by 100 relative to those used in FIG. 2 are being used to identify corresponding parts, the separating pistons 305 and 305' are resiliently displaced outwardly or downwardly as shown, the upper control openings 324 and 324' are uncovered by the control slides 321, and three exists a connection of the gas cushions 307 and 307' through the discharge conduits 312 and 312', the inlet chamber 326, and the then open turnable slide 317 with the low pressure accumulator 310 which acts as a gas sink, so that there can occur a return displacement of the separating pistons 305 and 305' into their desired positions shown in to FIG. 1 of the drawings in any arbitrary succession, and a level regulation by a decrease of the gas amounts in the gas cushions 307 and 307'.
When, as shown in FIG. 4 of the drawings in which reference numbers raised by 100 relative to those used in FIG. 3 are being used to identify corresponding parts, the left separating piston 405 is resiliently displaced upward and the right separating piston 405' is resiliently displaced, downwardly as considered in the illustrated position for instance during the performance of a right turn, due to the additional loading of the resilient element 401 and its attendant retraction and the reduced loading of the resilient element 401' and its attendant extension, the lower control opening 425 at the left and the upper control opening 424' at the right are uncovered by the respective control slides 421 and 421', and there exists a connection of the gas cushion 407 at the left with the gas cushion 407' at the right through the left supply conduit 413, the compressor 416 and the right discharge conduit 412'. Under these circumstances, the turnable slide 417 is closed, as shown in FIG. 4, after the level regulation of the carried load has been accomplished in the manner discussed above in conjunction with FIGS. 2 or 3 of the drawings, and no connection exists between the gas cushions 407 and 407' and the low-pressure accumulator 410. At this time, there can be accomplished a return displacement of the separating pistons 405 and 405' into their desired positions by transfer of a trimming amount of gas with the aid of the compressor 416 from the right to the left, that is, from the gas cushion 407' whose gas amount is reduced into the gas cushion 407 whose gas amount is increased, and there thus can occur a righting of the superstructure up to the desired position. When, after the completion of the right turn, the additional loading of the resilient element 401 and the reduced loading of the resilient element 401' are discontinued, the position of the separating pistons 405 and 405' is reversed, and there exists a connection of the left gas cushion 407 with the right gas cushion 407' through the left discharge conduit 412, the compressor 416 and the right supply conduit 413'. At this time, there can be accomplished a return of the separating pistons 405 and 405' by the return transfer of the trimming amount of gas, with or without the aid of the compressor 416, from the left to the right, that is, from the gas cushion 407 whose gas amount is reduced again into the gas cushion 407' whose gas amount is increased again.
The resilient elements have additional features which do not fall within the scope of protection of the present invention and will not be discussed here.
Turning now back to FIG. 1 of the drawings, it may be seen that each of the working pistons 104 and 104' is provided with a piston head 141 which is guided in the working cylinder 102 and is sealed with respect to the latter by a sliding seal 142. The working pistons 104 and 104' form with the working cylinder 102 an annular pumping space 143 whose pumping piston is constituted by an annular surface 153 of the piston head 141. An oil accumulator 146 is disposed between the cylinder lid 109 and the partitioning wall 150. The oil accumulator 146 surrounds the working cylinder 102 and is surrounded by an outer pipe 120. The oil accumulator 146 is provided at its lower portion with an oil filling 148 and at its upper portion with a gas filling 147 which is under pressure. A free oil upper level 149 is situated between the oil filling 148 and the gas filling 147. The pumping space 143 is connected with the oil filling 148 through a suction valve 144 and with the oil quantity 103 through a pressure valve 145. In addition, the pumping space 143 is connected with the oil quantity 103 through a throttling opening 131 which passes through the working cylinder 102 and is controlled by the piston head 141. In the position shown in FIG. 1 of the drawings, the throttling opening 131 is open half by the piston head 141. During swinging movements of the working piston 104, oil is drawn from the oil accumulator 146 and is supplied into the oil quantity 103, and oil flows back from the oil quantity 103 into the oil accumulator 146 through the throttling opening 131 as soon as the piston head 141 uncovers the throttling opening 131 during the resilient extension of the working piston 104. Herein, there is accomplished an equilibrium and an oil level regulation is effected, wherein the regulated level may correspond to the illustrated position of the resilient piston 104. The work performed by the pumping space 143 constitutes a load-depended damping and improves the damping properties.
In the arrangement of FIG. 5, in which the reference numbers have once more been increased by 100 with respect to those employed in FIG. 4, the parts of the arrangement group of FIG. 1 have been identified by reference numerals only in the case of need according to the invention, a gas container 510, which is effective as a low-pressure accumulator, is connected through a connecting conduit 538 which is equipped with a first turnable slide 517 with an inlet chamber 526 of a compressor 516, and through a second connecting conduit 539 which is provided with a second turnable slide 518 with the outlet chamber 527 of the compressor 516. The connecting conduit 538 opens via inlet channel 560 which is closeable by a valve 561 into a valve chamber 564 which is in open communication with the gas container 510. A valve spring 563 has the effect that a valve gap 562 exists between the inlet channel 560 and the valve 561. Because of this, when the turnable slide 517 is open, as illustrated, there can be accomplished a return displacement of the separating pistons 505 and 505' in exactly the same manner as described above in conjunction with FIG. 2 of the drawings. The connecting conduit 539 opens via an outlet opening 572 into a valve chamber 570 which is provided with a holding component 571 for a valve 567, and chamber 570 is connected through an outlet channel 566 which is closeable by the valve 567 with the gas container 510. A valve spring 569 is provided and is constructed to be so weak that, at a predetermined excess pressure of the gas cushions 507 and 507', the valve 567 keeps the outlet channel 566 closed. Thus, despite the open condition of the turnable slide 518, as illustrated, and the reduced pressure in the gas container 510, there can be accomplished return displacement of the separating pistons 505 and 505' due to the flow through the supply conduits 513 and 513'. When there is encountered the case that the pressure in the gas container 510 is higher than that in the gas cushions 507 and 507' and thus the gas container 510 is effective as a high-pressure accumulator, the valve gap 562 can remain open under the influence of the valve spring 563, the valve 567 is displaced outwardly against spring 569 by the excess pressure in the gas container 510, and an increase in the gas quantities in the gas cushions 507 and 507' can take place directly from the gas container 510 through the outlet channel 566 which is open under these circumstances.
In the arrangements according to FIG. 6, in which some of the reference numbers have once more been increased by 100 with respect to those employed in FIG. 5, there is accomplished a blowing-off of gas from the gas cushions 607 and 607' through the outlet conduits 612 and 612', the then operating compressor 616, the then open turnable slide 618 an the valve chamber 570 against the elevated pressure of the gas container 610. Herein, a valve gap 568 exists between the valve chamber 570 and the outlet channel 566 due to the influence of the valve spring 569. The excess pressure in the gas container 610 holds the inlet channel 560 closed by means of the valve 561 against the correspondingly elected weak spring force of the valve spring 563. Thus, despite the open condition of the turning slide 517 and the excess pressure in the gas container 610, it is possible to achieve the return displacement of the separating pistons 605 and 605' due to the action of the outlet conduits 612 and 612'.
The resilient elements 501 and 501' exhibit other features which do not fall under the scope of protection of the invention and will not be discussed here. The working pistons each are constructed as a stepped piston 504 which is guided in a working cylinder 502 and is sealed by a seal 542. The stepped piston 504 has a piston rod 552 which extends to the exterior of the working cylinder 502 through a cylinder lid 509 which is equipped with a seal 508. The large circular surface 541 of the stepped piston 504 displaces oil out of the oil quantity 503 that is enclosed in the working cylinder 502 and that is subdivided by a separating wall 550 provided with throttling openings 554. The piston rod 552 forms with an working cylinder 502 an annular space 528, from which the annular surface 559 displaces oil into an oil accumulator 546 which surrounds the working cylinder 502 through openings 523 arranged a the region of the cylinder lid 509. Herein, the oil accumulator 546 is provided at its lower portion with an oil filling 548 and at its upper region with a gas filling 547 which is subjected to pressure, while a free oil upper level 549 is present between the two fillings 548 and 547. The force exerted by the pressure of the gas filling 547 on the annular surface 559 acts as a pulling force for the piston rod 552, so that the resilient elements 501 and 501' are subjected to a carrying load equal to the pressure force with which the gas cushion 507 acts on the large circular surface 541 less the pulling force of the annular surface 559.
The piston rod 552 which is hollow forms a pump space 543, into which there extends a pumping plunger 551 which is connected to the intermediate wall 550 by means of a ball joint 558. The pumping plunger 551 is sealed by a seal 529. The pumping space 543 is connected with the annular space 528 through a suction valve 544 and with the oil quantity 503 through a pressure valve 545, and is additionally connected with the pressure accumulator 546 through a throttling opening 531 provided in the working cylinder 502 and controlled by the stepped piston 504. The pumping plunger 551 and the pumping space 543 have the same effects as described above with respect to the annular surface 159 and the pumping space 143 of the resilient elements according to FIG. 1.
Throttling openings 154 or 554 provided, according to FIGS. 1 or 5, in the intermediate walls 150 or 550, serve for a determination of the resilient and damping actions. These throttling openings 154 or 554 produce speed-dependent damping forces. Load-dependent damping forces are constituted in the self-pumping resilient elements, in a known manner, by the pumping work of the annular surface 159 of the piston head 141 according to FIG. 1 or of the pumping plunger 551 according to FIG. 5, and they can be varied by the size of the respective pumping surface or also by the throttling resistances of the suction and pressure valves 144 and 145 or 544 and 545. In the regulation in accordance with this invention, the gasside connection of the resilient elements has an influence on the damping forces, especially during low-frequency superstructure oscillations. Namely, when pressure differences are encountered, during alternating oscillations (compare FIG. 4) of a superstructure or during oscillations of the same sence (compare FIGS. 2. and 3), in the gas cushions of the associated resilient elements and a gas transfer takes place from one to the other of the resilient elements, the carried loads of the resilient elements are changed thereby and difference forces are created which appear as damping forces. This situation can be utilized for the determination of the resilience and damping, especially also in that the response sensitivity which determines the oscillations without gas transfer is varied during the return of the separating pistons toward their desired positions, in that, for instance, the overlaps of the control slide 121 and of the control openings 124 and 125 are selected to be correspondingly large. As a result of this, it can also be prevented that, when the pressure differences between the associated resilient elements are considerable, too much gas would flow in a disturbing manner from the gas cushion having the higher pressure to the gas cushion having the lower pressure. In order to influence this, throttling devices or locations may also be provided in the supply conduits or in the discharge conduits.
Two presumably frontward pneumatic resilient elements 1 and 2 which are shown in FIG. 7 include gas cushions 21 and 22 which are enclosed in housing 91 and 92 which correct respective upper separating pistons 11 and 12 with associated lower separating pistons 11' and 12' for movement together and apart. The pistons 11 and 12 or 11' and 12' are loaded toward one another by the pressure exerted thereon by the wheel load and away from each other by the pneumatic pressure of the gas cushions 21 and 22. Two presumably rearward pneumatic resilient elements 3 and 4 include gas cushions 23 and 24 which are enclosed in housing 93 and 94, and separating pistons 13 and 14, which are loaded at the side of hydraulic working cylinders 95 that are filled with oil by the wheel load and at the opposite side by the pneumatic pressure of the gas cushions 23 and 24. The gas cushions 21, 22, 23 and 24 are connected with position regulating elements 31, 32, 33 and 34 of a known construction, which detect the position of the separating pistons 11, 12, 13 and 14 and, in response to a deviation from a desired position, establish a communication with discharge conduits 41, 42, 43 or 44 or with supply conduits 51, 52, 53 or 54. Each of the discharge conduits 41, 42, 43 and 44 individually opens into an inlet chamber 86 of a compressor 82 through check valves 61, 62, 63 and 64 which open in the direction toward the inlet chamber 86. Each of the supply conduits 51, 52, 53 and 54 individually opens into an outlet chamber 88 of the compressor 82 through check valves 71, 72, 73 and 74 which close in the direction toward the outlet chamber 88. The compressor 82 includes a compressing piston 83 and a compressor cylinder 84, from which an inlet valve 85 connects to the inlet chamber 86 and an outlet valve 87 leads into the outlet chamber 88. A connecting conduit 80 is provided between the discharge conduits 41 and 42 at the region of the check valves 61 and 52. The connecting conduit 80 is equipped with a throttling arrangement 81.
The position regulating elements 31, 32, 33 and 34 are so arranged and switched that, in the event of a deviation of the separating pistons 11, 12, 13 and 14 from their desired positions which has been caused by the respective resilient element having been extended, they establish connection of the gas cushions 21, 22, 23 and 24 with the discharge conduits 41, 42, 43 and 44, and, in the event of a deviation caused by the resilient element being retracted, they establish connection of the gas cushions 21, 22, 23 and 24 with the supply conduits 51, 52, 53 and 54. The compressor 82 delivers gas directly from the gas cushions of the resilient extended resilient elements into the gas cushions of the resiliently retracted resilient elements in order to compensate for the vehicle tilting during dynamic vehicle movements. At this time, one or more of the check valves 61, 62, 63 and 64, and 71, 72, 73 and 74 open. For instance, when the resilient elements 2 and 4 are resiliently retracted and the resilient elements 1 and 3 are resiliently extended during a right-hand turn, gas is withdrawn from the gas cushions 22 and 24 through the discharge conduits 42 and 44 and supplied with the aid of the compressor 82 through the supply conduits 51 and 53 into the gas cushions 21 and 23, until the desired position of the separating pistons 11, 12, 13 and 14 is reached again. Herein, the check valves 62 and 64 which are interposed in the discharge conduits 42 and 44 prevent in an advantageous manner a pressure equalization between the gas cushions 22 and 24, while the check valves 71 and 73 associated with the supply conduits 51 and 52 prevent a gas equalization between the gas cushions 21 and 23. When, in accordance with the curve of the turn, the previously resilient extended resilient elements 2 and 4 become resiliently retracted and the previously resilient retracted resilient elements 1 and 3 become resiliently extended, gas flows from the gas cushions 21 and 23 through the discharge conduits 41 and 43 and the supply conduits 52 and 54 into the gas cushions 22 and 24, until the desired position of the separating pistons 11, 12, 13 and 14 is reached again. Herein, a position pressure differential exists for the return flow, and the compressor 82 may, but need not, be in operation. When the resilient elements 3 and 4 are resiliently extended and the resilient elements 1 and 2 are resiliently retracted as a result of a braking operation, the transport of the gas occurs in a manner which is the same as discussed above from the gas cushions 23 and 24 into the gas cushions 21 and 22 and, after the termination of the braking operation, gas transfer takes place instead back from the gas cushions 21 and 22 into the gas cushions 23 and 24. During braking in a curve, there occurs in a corresponding manner a gas transfer diagonally between the gas cushions 21 and 24, on the one hand, and the gas cushions 22 and 23, on the other hand.
When the carried loads of the resilient elements 1 and 2 are to be equal to one another, this is achieved by the connecting conduit 80 in that, during simultaneous resilient extension of both of the resilient elements 1 and 2 during pitching or diving of the motor vehicle, the pressure of the gas cushions 21 and 22 are connected to one another by means of the connecting conduit 80 through the discharge conduits 41 and 42. The connection of the gas pressures can be delayed in a desired manner by the throttling arrangement 81.
The subject matter of the construction according to FIG. 7 is exclusively inclination regulation, while a level regulation can be achieved in the manner discussed previously.
The inner spaces of the connecting conduits leading from the gas cushions to the position regulating elements constituted parts of the resiliently acting gas quantities. When these conduits are connected by the position regulating elements with the discharge or supply conduits, even the internal spaces of the discharge and supply conduits become part of the resiliently acting gas quantities. A a result of this, the resiliently acting gas quantities can be deleteriously influenced under certain circumstances. to avoid this, the distance of the position determining elements from the compressor may be small or at least smaller than the distance of the resilient elements from the compressor. So, for instance, the position determining elements can be shifted very closely to the compressor and the influence of the gas quantities contained in the discharge and supply conduits on the resiliently acting gas quantity can be fully or substantially eliminated.
While the present invention has been described and illustrated herein as embodied in a specific construction of a motor vehicle suspension, it is not limited to the details of this particular construction, since various modifications and structural changes are possible and contemplated by the present invention. Thus, the scope of the present invention will be determined exclusively by the appended claims. | A level and inclination regulating arrangement for a vehicle includes a compressor having an inlet chamber and an outlet chamber. At least two pneumatic or hydropneumatic resilient elements are each associated with one wheel of an axle of the vehicle and include a movable separating piston which is acted upon at one side by the wheel load, and a housing confining a gas cushion which exerts pneumatic pressure on and supports the separating piston at the other side. Supply and discharge conduits connect each of the gas cushions with the outlet chamber and with the inlet chamber of the compressor, respectively. An accumulator is incorporated into at least one of the supply and discharge conduits which communicates with the respective one of the outlet and inlet chambers. Position regulating elements are respectively associated with the resilient elements and are operative for detecting the position of the separating piston with respect to a desired position and for controlling the discharge of gas from the respective gas cushion into the discharge conduit and the supply of gas from the supply conduit into the respective gas cushion in dependence on the deviation of the respective separating piston from its desired position. A control valve selectively connects the accumulator with and disconnects the same from the connection through the respective one of the supply and discharge conduits. | 8 |
This is a continuation of application Ser. No. 07/181,430 filed on Apr. 14, 1988, abandoned as of the date of this application.
BACKGROUND OF THE INVENTION
This invention relates to genetic engineering of agriculturally useful microorganisms.
Certain naturally occurring microorganisms, e.g., microorganisms of the genus Klebsiella, e.g., Klebsiella pneumoniae, and microorganisms of the genus Rhizobium, e.g., R. meliloti and R. japonicum, are capable of converting atmospheric nitrogen into ammonia (“nitrogen fixation”). It has been proposed that the slow-growing soybean-colonizing bacterial species, known for decades as Rhizobium japonicum, be reclassified as Bradyrhizobium japonicum, to distinguish it from faster growers such as R. meliloti, R. phaseoli, etc. Other newly discovered, fast-growing soybean colonizers previously classified as Rhizobium fredii are now known and in all the claims as R. japonicum. Rhizobium herein refers to all Rhizobium and Bradyrhizobium species. R. japonicum, as used herein with reference to the Figures and preferred embodiments, means the slow-growing bacteria now known as B. japonicum, and genetic constructions devised therefrom. K. pneumoniae, a facultative anaerobe, can fix nitrogen in a free-living state, while Rhizobium and Bradyrhizobium species normally require a symbiotic relationship with leguminous plants.
The transcendent importance of nitrogen fixation in sustaining the biosphere has been recognized for much of the present century. In the last two or three decades the world's human population has outstripped the ability of natural nitrogen fixation processes, spontaneous and biological, to support adequate food production, so that more than 30% of the world's population now depends on artificial nitrogenous fertilizer for its minimal nutrition.
In addition to Rhizobium and Klebsiella species, prokaryotes naturally able to fix nitrogen include obligate anaerobes (e.g., Clostridium pasteurianium ), obligate aerobes (e.g., Azotobacter vinelandii ), photosynthetic bacteria (e.g., Rhodospirillum rubrum ), and some strains of blue-green algae (e.g., Anabaena cylindrica ).
A symbiotic relationship can exist between Rhizobium and legumes (e.g., soybeans or alfalfa). Such a relationship begins with host-symbiont recognition and penetration of the root by Rhizobium, and culminates in the differentiation of the bacterium into the nitrogen-fixing “bacteroid” form within the root nodule. It is only in the bacteroid form that nitrogen is fixed by Rhizobium. Rhizobium species exhibit host-range specificity: for example, R. japonicum infects soybeans, and R. meliloti infects alfalfa.
The plant species commonly used in commercial agriculture cannot fix their own nitrogen unless in symbiotic association with nitrogen fixing microorganisms and are thus reliant, in general, on the addition of nitrogenous fertilizers. However, the symbiotic relationships between legumes and Rhizobium have long been exploited in commercial agriculture. Various strains of Rhizobium are currently sold commercially, to be used as “inoculants” to increase the yields of legume crops such as soybean, alfalfa, and closer. Rhizobial inoculants have been sold in significant volume in the U.S. since 1959, and it has been estimated by the USDA that 50% of the total U.S. acreage of soybean crops and 80% of alfalfa crops are inoculated.
Although rhizobial products are used to such an extent in this country, the existing products are believed not to be very effective in promoting yield increases. One reason for this might be poor competition between the introduced strains and those strains indigenous to the soil.
In nitrogen fixing microorganisms there are genes coding for products involved in the nitrogen fixation pathway. In K. pneumoniae, these genes are known as the “nif” genes. Analogous sets of genes are present in other nitrogen fixing species (perhaps arranged differently in each species). The nif genes of K. pneumoniae are arranged in sequence in 7-8 operons. One operon contains the structural genes coding for the protein subunits of the major enzyme in the nitrogen fixation pathway, nitrogenase. The nitrogenase operon is composed of a promoter (the nifH promoter); the three subunit structural genes, nifH, nifD, and nifK; and the nifT and nifY genes, of unknown function. Another operon is composed of a promoter and the nifL and nifA genes. The nifA gene encodes a transcriptional activator protein, the nifA protein, which is required for the expression of all operons containing the nif genes, except its own. The nifL gene codes for a protein which renders the nifA transcriptional activator protein nonfunctional, and thus serves to repress nitrogen fixation. (References herein to the nifA gene, the nifL promoter, and the nifH gene and promoter are intended to include DNA derived from K. pneumoniae, as well as functionally equivalent DNA derived from any other nitrogen fixing bacteria.)
Buchanan-Wollaston et al., 1981, Nature 294:776 report an investigation of the role of the nifA gene product in the regulation of nif expression. A variety of Klebsiella pneumoniae strains were transformed with either of two plasmids constructed to permit constitutive expression of the nifA gene product. In pMC71A the nifA gene was cloned into the tetracycline resistance gene of the plasmid pACYC184 and transcribed from the promoter of the tetracycline resistance gene. In pMC73A, the nifA gene was cloned into the kanamycin resistance gene of the plasmid pACYC177 and transcribed from the promoter of the kanamycin resistance gene. Expression of nifA from these plasmids was tested in a mutant-strain of K. pneumoniae which does not express normal nifA activity. Both plasmids were observed to complement the nifA mutation. Constitutive nif expression in the presence of NH4 + (a negative effector of nif transcription initiation) was also examined by measuring β-galactosidase activity in a K. pneumoniae strain using a genomic fusion of the nifH promoter in reading frame with the lacZ gene.
SUMMARY OF THE INVENTION
The present invention provides a strategy for improving crop yields, involving increasing nitrogen fixation in nitrogen fixing bacteria via genetic engineering.
In general, the invention features a vector for transforming a host microorganism which contains DNA encoding one or more proteins capable of effecting the conversion of atmospheric nitrogen into ammonia in the microorganism, the vector being capable of increasing the capacity of the microorganism to so convert atmospheric nitrogen, the vector including a gene encoding an activator protein capable of activating the transcription of that DNA, the activator protein-encoding gene preferably being under the transcriptional control of an activatable promoter sequence.
Microorganisms transformed with the vector have an improved capacity to fix nitrogen. The activator protein which is normally present in only a limited amount is, by virtue of the vector, produced in a much greater amount which results in increased production of nitrogenase from the nif genes of the host microorganism (although too great an amount of the activator protein can actually be detrimental to plant growth). Thus, even in the presence of a nifL-like repressor protein, there is sufficient overproduction of nifA protein to activate nitrogenase production. Furthermore, the use of an activatable promoter allows for high levels of nifA protein production at the time the host cell initiates nitrogen fixation.
Alternatively, the same effect can be achieved by placing the inserted nifA gene under the transcriptional control of a constitutive promoter, e.g., the promoter of a bacterial gene for kanamycin resistance.
Nitrogen fixing bacteria transformed with a vector of the invention, living in association with legume crops with which the bacteria can live symbiotically, can increase the yields of those crops by virtue of the improved nitrogen fixation provided by the bacteria.
The invention also features a method for stably integrating, by homologous recombination, a DNA sequence into a silent region of the Rhizobium chromosome. This method can be used for integrating a cloned gene of the invention, capable of increasing the microorganism's ability to convert atmospheric nitrogen, or any other desired gene.
Other features and advantages of the invention will be apparent from the following description of preferred embodiments thereof, and from the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
We now describe preferred embodiments of the invention, after briefly describing the drawings.
Drawings
FIG. 1 is a diagrammatic representation of the vector pRmB3.8H, containing the R. meliloti nifA gene.
FIG. 2 is a diagrammatic representation of the vector pRAR566, containing the R. japonicum nifA gene.
FIGS. 3 and 5 are diagrammatic representations of the vectors pMW122 and pJB81, containing the R. meliloti nifH promoter.
FIG. 4 is a diagrammatic representation of the construction of the vector pMW113, containing the R. japonicum nifD promoter.
FIG. 6 is a diagrammatic representation of the construction of vector pJB124, containing the R. meliloti fixA promoter.
FIGS. 7 a - 7 d are diagrammatic representations of vectors containing the K. pneumoniae nifH(a), K. pneumoniae nifE(b), K. pneumoniae nifU(c), and K. pneumoniae nifM(d) promoters.
FIG. 8 is a diagrammatic representation of the construction of the broad host-range vector pJB151.
FIG. 9 is a diagrammatic representation of pJB110, a vector used in the construction of the vector of FIG. 10 .
FIG. 10 is a diagrammatic representation of the vector pJB111, containing the R. meliloti nifA gene fused to the kanamycin resistance gene promoter.
FIG. 11 is the nucleotide sequence of the 5′ end of the R. meliloti nifA gene (A) and oligonucleotides (B, C) used in the construction of derivatives thereof.
FIG. 12 is a diagrammatic representation of the vector pMW142 containing the R. japonicum nifH promoter fused to the R. meliloti nifA gene.
FIG. 13 is a diagrammatic representation of the construction of the vector pJB154, containing the cat promoter fused to the R. meliloti nifA gene.
FIG. 14 is a diagrammatic representation of the vector pMW148, containing the R. japonicum nifH promoter fused to the R. meliloti nifA gene preceded by a synthetic Shine-Dalgarno sequence.
FIG. 15 is a diagrammatic representation of the vector pJB191, containing the R. meliloti nifA gene preceded by a synthetic Shine-Dalgarno sequence and fused to the cat promoter.
FIG. 16 is a diagrammatic representation of an insertion vector.
FIG. 17 is the nucleotide sequence of a synthetic linker containing a majority of the R. meliloti nifH leader sequence.
FIG. 18 is a diagrammatic representation of vector pIC-20H and derivatives thereof.
FIG. 19 is a diagrammatic representation of the construction of pMW153, containing the nifD promoter and the nifH synthetic leader fused to the nifA gene.
Vector Components
As mentioned above, the vectors of the invention contain several essential DNA regions and sites, now described in greater detail.
Transcriptional Activator Gene and Promoter Sequence
According to the invention, a plant's ability to assimilate nitrogen by virtue of its symbiotic association with a nitrogen fixing bacterium is increased by the introduction of a bacterium, preferably Rhizobium, which has been transformed with a vector which contains a gene for an activator protein, under the transcriptional control of a promoter, preferably an activatable promoter. Any suitable activator protein can be used, in conjunction with any suitable promoter. The most preferred activator protein gene/promoter combination is a nifA gene, under the transcriptional control of a nif promoter, e.g., a nifH promoter. The following is a more detailed description of the nif system and the operation,of these two components in nature and according to the invention.
As is mentioned above, the product of the nifA gene is a transcriptional activator protein required for the initiation of transcription of the promoters of all the nif operons except its own. The gene product of nifL acts as a repressor of nif transcription by combining with the nifA protein and inactivating it, preventing the activation of nif transcription and expression of the nitrogen fixation pathway. The nifL repressor is, in its active form, able to sequester the nifA protein only under intracellular conditions of high fixed nitrogen or oxygen concentration. Under conditions of low intracellular fixed nitrogen concentration, the nifL repressor is inactive. The nifA and nifL protein thus make up a feedback inhibition loop which shuts down nitrogen fixation when fixed nitrogen and oxygen are present at high concentrations.
Another nif operon is composed of nifH, nifD, nifK, nifY and nifT. The first three genes of the operon code for subunits of the chief enzyme of the nitrogen fixation pathway, nitrogenase. Of all the nif operon promoters, the nifH promoter probably has the highest affinity for the nifA activator protein; the nifH promoter binds the activator so tightly that, if multiple copies of the nifH promoter (carried on plasmids) are introduced into a cell, they will titrate out all of the nifA protein present. This high affinity is believed to be the reason the nifH promoter is the strongest of the nif promoters.
The nifA gene, engineered to be transcribed under the control of the nifH promoter, effects an increased intracellular concentration of nifA protein. This increased concentration cannot occur naturally because the feedback inhibition system causes derepression of the nif system and increased nitrogenase production with concomitant nitrogen fixation independent of intracellular fixed nitrogen or oxygen concentrations.
Although the nifA gene is substantially homologous between species, the sequences are not identical. Thus, it is preferable according to the invention to employ a nifA gene or portion thereof identical to that of the host microorganism (e.g., the R. meliloti gene in an R. meliloti host). There can be employed either the intact nifA gene or a derivative in which the corresponding N-terminal domain, which may be involved in binding the nifL repressor, is deleted. Deletion of this domain renders the nifA protein a more efficient promoter activator. Drummond et al. (1986, EMBO J. 5:441) aligned the amino acid sequences of the nifA proteins of R. meliloti and K. pneumoniae and showed that there are domains of homology separated by less similar segments of variable lengths. The N-terminal homologous domains of the nifA proteins (collectively referred to as domain A which extends from amino acid 10 to amino acid 163 of R. melitoti nifA, and from amino acid 22 to amino acid 182 of K. pneumoniae nifA, Drummond et al., supra.) were determined to be functionally involved with the repression of nifA promoter activation. We found that the deletion of a region encompassing amino acids 2 through 166, which includes domain A, rendered the nifA protein a more efficient transcriptional activator, probably due to the lack of the repressor binding region.
In addition to regulated (i.e., activatable) promoters such as the nif promoters, a promoter which can constitutively effect transcription of the nifA gene, e.g., the readily available promoter from the kanamycin resistance gene can also be used.
Selectable Marker
Because transformation of microorganisms with plasmids is a relatively rare event, plasmids of the invention preferably contain a DNA region which encodes a selectable marker protein for the identification of transformants. This marker protein can be any protein which can be expressed in host cells and which enables the phenotypic identification of microorganisms which express the protein. Preferred marker proteins are proteins which confer resistance to one or more antibiotics, e.g., chloramphenicol. Transformants are those microorganisms able to grow in the presence of the antibiotic.
Plasmid Construction
Plasmids can be constructed using a number of different combinations of promoters and nifA genes. The R. meliloti nifA gene, in combination with any of several promoters, is used for transformation of R. meliloti; the B. japonicum nifA gene, in combination with suitable promoters, is used with B. japonicum.
NifA Genes
R. meliloti nifA Gene
The R. meliloti nifA gene is obtained from a 2.4 kb HgiAI fragment of plasmid pRmB3.8H (FIG. 1, and described in Szeto et al., 1984, Cell 36: 1035). The sequence of the R. meliloti nifA gene is given in Buikema et al., 1985, Nuc. Acid Res. 13: 4539.
B. japonicum nifA Gene
The nifA gene of B. japonicum 110 is located immediately upstream of the putative fixA gene. Using a 20-mer oligonucleotide based on the B. japonicum fixA coding sequence (5′ CCGGACTCGGCGCAGATCCG3′) as a probe, we determined that both genes are located on a 5.4 kb HindIII-BamHI fragment of the B. japonicum genome. To isolate this fragment, B. japonicum DNA was digested with BamHI and separated on a sucrose gradient. Fractions containing large (20-25 kb) fragments showed the highest levels of hybridization to labelled 20-mer probe. This DNA was digested with HindIII and ligated into pBR327 that had been treated with HindIII, BamHI, and alkaline phosphatase. The 5.4 kb fragment, which includes both the nifA and fixA genes, was recovered from an E. coli transformant on a plasmid called pFCC301. A 3.46 kb HincII-PstI fragment spanning the nifA gene was removed from pFCC301 and cloned into the BglII site of pJB120 (derived from pACYC184 by changing the Tagl site between the Shine-Dalgarno (SD) sequence and transcription start site to BglII, FIG. 6) after conversion of the termini to BamHI sites using oligonucleotide linkers. This subcloning was done to separate the fixA gene from the nifA fragment. The resulting plasmid, pRAR566, is the storage vector for the B. japonicum nifA gene (FIG. 2 ). The nucleotide sequence of the nifA gene was determined and is given in Thony et al, 1987, Nucl. Acid Res. 15:8479.
R. meliloti nifA gene with domain A deleted
Plasmid pJB203, with domain A of the nifA gene deleted, and the naturally occurring Shine-Dalgarno sequence replaced with a superior synthetic SD sequence was constructed as described below. pJB182, which contains a modified form of the nifA gene fused to the E. coli cat promoter was used as the starting plasmid. Plasmid pJB182 was derived by replacing the natural SD sequence of the nifA gene in plasmid pJB160 with a synthetic SD sequence that has a stronger binding affinity for ribosomes and then replacing the fixA promoter of pJB160 with the cat promoter. The natural sequence of the 5′ end of the nifA gene, and 61 base pairs extending upstream, are shown in FIG. 11, Panel A. A synthetic DNA fragment which encodes a more efficient SD sequence (shown in Panel B) was cloned into the DNA sequence of Panel A, following digestion of pJB160 with BglII and FspI (partial) to remove the natural SD sequence, creating pJB180. An SphI site was introduced into pJB180 at the 3′ end of the linker fragment. The fixA promoter of pJB180 was then replaced by the cat promoter, creating pJB182.
The deletion of domain A from pJB182 was achieved by the following procedure. The sequence extending from amino acid position 2 through amino acid position 168 of the nifA protein was deleted by cleaving pJB182 with SphI and EcoRI and replacing the deleted fragment with the oligonucleotide shown in Panel C of FIG. 11 . This resulted in the deletion of all of domain A and re-created the last four amino acids of the linker region between domains A and C (amino acids 169-172) and the first seven amino acids of domain C preceding the EcoRI site (amino acids 173-179). The resulting plasmid is pJB203.
Promoters
Various promoters have been isolated for ligation to the above or other nifA genes, and in order to express the nifA gene at suitable levels to cause increased nitrogen fixation. Certain guidelines can be followed to determine if a promoter is likely to produce optimal nifA expression. These guidelines are not meant to exclude any potentially useful promoters and it is recognized that exceptions to these guidelines will be found. Nevertheless, the guidelines can be generally applied to the process of choosing appropriate promoters for increased production of nifA leading to an increased nitrogen fixing capacity.
In general, strong constitutive promoters should be avoided. We have discovered that the production of nifA above an optimal level is detrimental to plant growth. Strong unregulated expression of the nifA gene results in the production of levels of nifA protein that inhibit the growth of the plant. Similarly, strong homologous promoters (i.e., promoters found naturally in the same bacterium) should be avoided. A strong homologous promoter will also lead to the production of excessive amounts of nifA, which are detrimental to the plant. Thus, we have found that strong heterologous promoters (i.e., promoters not naturally occurring in the bacterium) are the most suitable for providing increased nifA production, at a level that is beneficial, not deleterious, to the plant. Nif promoters are generally less active in a nonhomologous environment, and therefore, a strong nif promoter in a heterologous host will express adequate, elevated, levels of nifA protein. Examples of such promoters follow.
B. japonicum nifH Gene Promoter
The nucleotide sequence of the B. japonicum nifH promoter is described in Fuhrmann and Hennecke, 1984, J. Bact. 158:1005. Referring to FIG. 3, the B. japonicum nifH promoter is carried on pBJ33 (obtained from Barry Chelm at Michigan State University), on a SalI insert in pBR322.
A region containing the B. japonicum nifH promoter was isolated on a 0.15 kb BglII-HgiAI fragment. The HgiAI end was converted to a BamHI site using a linker, and this fragment was cloned into the BamHI site of pBR322 to give pMW115. The BamHI-SalI fragment of pMW115, with the BamHI site converted to BglII by a linker, was cloned into the ClaI-SalI site of pSUP104, a broad host-range vector described by Simon et al. in Molecular Genetics of the Bacteria Plant Interaction 98-106, A. Puhler ed. 1983; and Puhler et al. U.S. Pat. No. 4,680,264, hereby incorporated by reference. The ClaI site was converted to BglII using a linker, to give pMW116 (FIG. 3 ).
The B. japonicum nifH (and nifA, see below) promoter contains conserved putative upstream nifA binding sequences, described in Buck et al., 1986, Nature 320: 374. Deletion or mutation of these conserved sequences has been shown to result in a decrease in promoter strength in E. coli (Alvarez-Morales et al., 1986, Nucl. Acid Res. 14: 4207). The B. japonicum nifH promoter contains two upstream nifA binding sites, one located at −111 and the other at −140 relative to the +1. On analysis, pMW116 was found to contain only the binding site at position −111. The other site, located at −140, was inadvertently deleted.
In order to clone the nifH promoter including the −140 site, the vector pMW116 was modified in order to include both upstream nifA binding sequences, as follows. A 1.85 kb HindIII-SalI fragment from pBJ33 containing both putative upstream binding sequences was cloned into the HindIII-SalI site of pMW116, replacing a fragment which contained only one binding sequence (FIG. 3 ). The resulting plasmid, pMW122, was partially BamHI digested, filled in and religated, in order to eliminate the BamHI site upstream from the nifA binding sequences. The resulting plasmid, pMW126, allowed for cloning into the BamHI linker site downstream from the B. japonicum nifH promoter, and serves as a storage vector for the B. japonicum nifH promoter.
Activation of nifH Promoted Gene Expression
Data presented in Table 1 show a comparison of the level of gene expression from the nifH promoter of either K. pneumoniae or R. meliloti when activated with one of three versions of the nifA gene product. In the test plasmids, all forms of the nifA gene are expressed from the E. coli cat promoter. Referring to FIG. 13, pJB135 containing the nifA gene with its natural SD sequence was constructed by cloning the BqlII fragment from pJB131 (derived from pJB110, infra, by changing one NruI site 24 bp past the end of the nifA gene to a BglII site), containing the nifA gene, into BglII digested pJB120. The nifA protein expressed from pJB135 causes expression of lacZ from the nifH promoter at a level only slightly higher than background. In pJB182, in which the nifA gene is fused to the synthetic SD sequence, expression of the lacZ gene from the R. meliloti promoter is increased approximately 2.4-fold above background. The increase in β-galactosidase expression is much more pronounced when the synthetic SD sequence is fused to the nifA gene which has been deleted for domain A (pJB203). In this case, expression from the nifH promoter is enhanced 15-fold above background.
TABLE I
Activation of promoters by nifA protein
K.p. nifH P::lacZ
R.m. nifH P::lacZ
(pJB31)
(pVSP9)
pJB120
2.1
850
pJB135
3.3
909
pJB182
16.4
2028
pJB203
1853.0
12649
B. japonicum nifD Gene Promoter
The nucleotide sequence of the B. japonicum nifD promoter is described in Kaluza and Hennecke, 1984, Mol. Gen. Genet. 196:35. Referring to FIG. 4, the B. japonicum nifD promoter is carried on pRJ676Δ1 (obtained from Barry Chelm), a derivative of pRJ676 (Hennecke, 1981, Nature 291:354). The B. japonicum nifD promoter was isolated from pRJ676Δ1 on the 370 bp AhaIII to BglII fragment. The AhaIII end was converted to BamHI using a linker. The BamHI-BglII fragment was then subcloned into the BamHI site of pACYC184 to give pMW113. The tetracycline resistance promoter was deleted by cutting with ClaI and BamHI and inserting a BglII linker to give pMW114. This gave a tailored version of the B. japonicum nifD promoter, allowing genes to be expressed from the nifD promotor by inserting them into the BglII site of pMW114. The XbaI-SalI fragment of pMW114 was cloned into XbaI+SalI cut pSUP104, to give pMW117.
Chloramphenicol acetyl transferase (cat) promoter
The nucleotide sequence of the E. coli cat promoter is given in Alton et al., 1979, Nature 282:864. The promoter for the cat gene is a constitutive promoter carried on pJB120, which was constructed by converting a TaqI site of pACYC184 (FIG. 4) to a BglII site using an oligonucleotide linker. This site lies between the transcriptional start and the SD sequence of the cat gene and provides a convenient location for cloning genes under cat promoter control.
R. meliloti nifH Gene Promoter
The nucleotide sequence of the R. meliloti nifH gene promoter is given in Sundaresan et al., 1983, Nature 301:728. Referring to FIG. 5, there is shown plasmid pJB81, containing the R. meliloti nifH promoter. pJB81 was constructed by first cloning a 680 bp SalI-SphI fragment from pRmR2 (Ruvkun et al., Nature, 1981, 289:85) into SalI-SphI digested pACYC184, then digesting the resulting plasmid (pJB80) with SphI and HindIII and ligating in SmaI linkers. This created a unique SmaI site immediately downstream of the R. meliloti nifH promoter sequence.
R. meliloti fixA Gene Promoter
The nucleotide sequence of the R. meliloti fixA gene promoter is given in Earl et al., 1987, J. Bact. 169:1127. The R. meliloti fix gene cluster was isolated on a 5 kb EcoRI fragment from plasmid pWB1083 (obtained from F. Ausubel, Buikema et al., 1983, J.Mol. Appl. Genet., 2:249). This EcoRI fragment was cloned into the EcoRI site of pACYC184 (FIG. 4) to give pJB117 (FIG. 6 ). A MaeI site was identified at the +2 position relative to the transcription start site. The fixA promoter region was removed from pJB117 by cleavage with MaeI, conversion of the MaeI ends to BglII ends with synthetic linkers, and then EcoRI and BglII digestion. The fragment containing the fixA promoter region was ligated into EcoRI+BglII digested pJB120 to create pJB124 (FIG. 6 ).
K. pneumoniae nifH Gene Promoter.
The nucleotide sequence of the K. pneumoniae nifH gene promoter is given in Sundaresan et al., (1983, Nature 301:728) and Scott et al., (1981, J. Mol. Appl. Genet. 1:71). The K. pneumoniae nifH promoter was isolated from pKA3 (pACYC184 having a 0.6 kb EcoRl-BglII fragment of pVW16, described by Buchanan-Wollaston et al., 1981, Mol. Gen. Genet. 184:102, inserted at the EcoRI site) on a 471 bp EcoRI-SacII fragment and cloned into ClaI and BamHI digested pSUP104, resulting in pRK37 (FIG. 7 a ).
The fragment containing the nifH promoter also contained part of the nifJ promoter region which is transcribed in the opposite direction from a site further upstream. The nifH promoter was thus cloned independent of the nifJ promoter region by removing the Ncol-BamHl fragment from pRK37 and recloning it into Ncol-BamHl digested pJB120. The resulting plasmid is designated pRK372.
K. pneumoniae nifE Gene Promoter.
The nucleotide sequence of the K. pneumoniae nifE gene promoter is described in Beynon et al., 1983, Cell 34:665. The K. pneumoniae nifE promoter was isolated on a SmaI-HincII restriction fragment from pVW10 (pBR322 containing the EcoRI-SalI nifE promoter fragment of K. pneumoniae inserted at the EcoRI-SalI sites; Beynon et al. Cell 34:665). The SmaI-HincII ends were converted into ClaI and BamHI ends and inserted into ClaI+BamHI digested pSUP104, creating pRK11. (FIG. 7 b ).
K. pneumoniae nifU Gene Promoter.
The nucleotide sequence of the K. pneumoniae nifU gene promoter is described in Beynon et al., (id.). The K. pneumoniae nifU promoter was isolated from pMC11 (pBR322 containing the nifU fragment from K. pneumoniae ) on a BamHI-SacII fragment and cloned directly into the BamHI-SacII sites of pSUP104, to create pRK3B (FIG. 7 c ).
K. pneumoniae nifM Gene Promoter.
The nucleotide sequence of the K. pneumoniae nifM gene promoter is given in Beynon et al., (id.). The K. pneumoniae nifM promoter was subcloned on a XhoI-SalI fragment from pMC12 (pBR322 containing the EcoRI-PstI nifM promoter fragment of K. pneumoniae, Beynon et al. Cell, supra.) into the SalI site of pSUP104, resulting in pRK415. The promoter for the tetracycline resistance gene was subsequently removed by deleting plasmid sequences between the ClaI site and the SphI site. The resulting plasmid is designated pRK415Δ (FIG. 7 d ).
Construction of Broad Host Range Vector pJB151
Fusions of nifA genes to suitable promoters are transformed into Rhizobium using broad host range vectors, for example, pSUP104. We found that pSUP104 may have an inherent detrimental effect on nitrogen fixation when transformed into R. meliloti. Referring to FIG. 8, we therefore chose to use a derivative of a different broad host range vector, pRK290 (Helinski U.S. Pat. No. 4,590,163, hereby incorporated by reference), which we showed had no such detrimental effect. The derivative vector, pJB151, was constructed as follows.
We began with plasmid pWB5, made by inserting the kanamycin resistance gene and a multiple-cloning site polylinker into the EcoRI site of pRK290 (FIG. 8 ). The kanamycin resistance gene was removed by BamHI digestion, and the plasmid was religated to give pJB151. The polylinker remained at the former EcoRI site, providing a number of convenient restriction endonuclease sites for the insertion of promoter::nifA fusions. Any of the fusions described below can be inserted into pJB151, at any of several sites.
Construction of Promoter::nifA Gene Fusions
Kan Promoter:: R. meliloti nifA
pVW60 contains the Tn5 kanamycin resistance structural gene and its constitutive promoter. It was constructed by ligating the HindIII-SalI fragment from pMS1000 (Filser et al., 1983, Mol. Gen. Genet. 191:485) into HindIII and SalI digested pBR327. The HindIII-SalI fragment of pVW60 was excised and cloned into the HindIII-SalI site of pACYC184 (FIG. 4) yielding pJB98.
The HgiAI fragment carrying the R. meliloti nifA gene was isolated from pRmB3.8H (FIG. 1 ). BglII linkers were added so that the fragment could be cloned into pJB98 at the BglII site, which lies between the structural gene for kanamycin resistance and its promoter. This step yielded pJB110 (FIG. 9) in which the R. meliloti nifA gene is constitutively expressed from the Tn5 kanamycin resistance gene promoter.
In order to insert the desired construction into the broad host range vector pSUP104, pJB110 was digested with HindIII and SmaI and the HindIII-SmaI fragment containing the Tn5 kanamycin resistance gene promoter:: R. meliloti nifA gene fusion was isolated and cloned into the HindIII-NruI site of pSUP104 to yield plasmid pJB111 (FIG. 10 ).
The insert fragment carried on pJB110 and pJB111 also contains a portion of the R. meliloti nifB gene, including its promoter. The presence of the nifB promoter could be detrimental to increasing nitrogen fixation since, as a nitrogen-regulated promoter, it contains a binding site for nifA protein, and would serve to titrate nifA protein away from the promoters to which it is desired that nifA protein bind. We therefore subcloned the nifA gene from pJB110, on a restriction fragment not containing the nifB promoter, as follows.
An NruI site was discovered to be located 24 bp downstream from the end of the nifA gene, in addition to three other NruI sites within the plasmid. pJB110 was digested partially with NruI; full-length linear DNA was isolated, and a BglII linker was ligated in. This resulted in four derivatives that had new BglII sites. Plasmid pJB131 was the derivative which contained a BglII site in the desired location. This permitted the nifA gene to be isolated on a 1.7 kb BglII fragment free of the nifB promoter. The above described procedure can also be performed on pJB111, to yield the same BglII fragment.
Referring to FIG. 11 Panel A, an additional change was made to increase expression of the R. meliloti nifA gene, involving the Shine-Dalgarno (SD) sequence. The natural SD sequence preceding the nifA gene is a relatively weak ribosome binding site based on a comparison with other known SD sequences. We chose to replace the original SD sequence of the nifA gene in pJB160 (carrying a R. meliloti fixA promoter:: R. meliloti nifA gene fusion; see above, and FIG. 6) with a synthetic DNA sequence that more closely resembles the E. coli 16S RNA ribosome binding site. pJB124 was cleaved with BglII and ligated with the above described BglII nifA fragment of pJB98 to form pJB140; the BglII site, downstream of nifA gene was changed to PstI, using linkers, to form pJB152; and an EcoRl site upstream of the fixA promoter in pJB152 was changed to HindIII, to give pJB160. This DNA was partially digested with FspI, which cuts just after the first ATG of the nifA gene. A 39 bp fragment was synthesized having a BglII sticky end on the 5′ terminus. The sequence of the synthetic DNA recreates the original ATG and the FspI restriction site, as well as changing the SD sequence. Ligation of FspI digested plasmid with the synthetic fragment was followed by BglII digestion (to cut the gene just upstream of the natural SD) and religation to insert the new SD sequence. A clone was selected which had the linker inserted in the correct location. This plasmid is pJB180. Another plasmid derived from pJB180 which contains a cat promoter in place of the fixA promoter is pJB182.
B. japonicum nifH:: R. meliloti nifA
The 1.7 kb BglII fragment from pJB131 containing the R. meliloti nifA gene with its natural SD sequence was cloned into the BamHI site of pMW126 to give pMW128, in which the nifA gene is under the control of the B. japonicum nifH promoter. To transfer the fusion into a pRK290-based vector, the SalI fragment was removed from pMW128, and the termini were converted to ClaI sites with linkers, followed by ClaI+XbaI digestion. The 3.4 kb ClaI-XbaI fragment, containing the entire B. japonicum nifH promoter and the two upstream binding sequences in addition to the R. meliloti nifA gene, was cloned into ClaI+XbaI digested pJB151 (FIG. 8) to yield plasmid pMW142 (FIG. 12 ).
Cat promoter:: R. meliloti nifA (original SD)
The nifA gene was excised from pJB131 on a 1.7 kb BglII fragment and cloned into the BglII site of pJB120, adjacent to the cat promoter, to give pJB135 (FIG. 13 ). To transfer this to pJB151, a PvuII fragment containing both the cat promoter and the nifA gene was excised from pJB135. The ends were converted to HindIII by the addition of synthetic linkers and the fragment was cloned into the HindIII site of pJB151, resulting in pJB154 (FIG. 13 ).
B. japonicum nifH::new SD/ R. meliloti nifA
The R. meliloti nifA gene preceded by the synthetic SD sequence was removed from pJB182 by the following method. The plasmid was cleaved with PstI and the site was converted to a BglII site with a synthetic linker. Subsequent digestion with BglII released a 1.7 kb fragment containing the nifA gene. This fragment was ligated with BamHl digested pMW126 to give pMW145 in which the R. meliloti nifA gene was under the control of the B. japonicum nifH promoter in a pSUP104 vector backb one. The HindIII-XbaI fragment of pMW145 which spans the nifA gene including the synthetic SD sequence, was cloned into HindIII+XbaI digested pMW142 (FIG. 12 ), thereby replacing the authentic nifA gene fusion in a pRK290 derived backbone. The final plasmid is designated pMW148 (FIG. 14 ).
Cat::new SD/ R. meliloti nifA
The R. meliloti nifA gene was cloned under control of the cat promoter by removing the BglII-PstI fragment from pJB180 and ligating it with BglII+PstI digested pJB167 (derived by digesting pTR1300, 1986, J. Virol. 60:1075, with BglII, and ligating the fragment containing the lac genes into BglII-digested pJB120, to give pRK1301; the NcoI site following the lacZ gene was converted to PstI to give pJB163, and the XmnI site was converted to HindIII to give pJB167), a cat::lacZ fusion vector, resulting in the replacement of the lacZ gene. The cat promoter::nifA fusion was then removed from the new construct (pJB182) by digestion with HindIII and PstI and cloned into HindIII+PstI digested pJB151 (FIG. 8 ). This resulted in plasmid pJB191 (FIG. 15 ).
Cat:: B. japonicum nifA
The cat promoter:: B. japonicum nifA fusion construct (pRAR566) was described above. To reclone the fusion into pJB151, the PvuII fragment was excised from pRAR566, the ends were converted to HindIII with synthetic linkers and then ligated into the HindIII site of pJB151 (FIG. 8) to generate pRAR576.
Microorganism Hosts
Any Rhizobium or Bradyrhizobium strain is a suitable host, particularly one that is an effective nodulator. Suitable hosts for transfer of recombinant plasmids include the following: R. meliloti strain RCR2011, strain SU47 and strain 41; B. japonicum strain USDA 136; B. japonicum strains USDA 110 and USDA 123; R. fredii strain USDA 205. These and many other known strains are publicly available from the ATCC or from the Rothamsted Collection of Rhizobium (Rothamsted Experimental Station, Harpenden, Hertfordshire, U.K.). In addition, the IBP World Catalogue of Rhizobium Collections (Allen et al., 1973, International Biological Programme, London) provides a listing of inocula available worldwide.
Certain indigenous strains can be isolated from the field as representing dominant species (Jenkins et al., 1985, Soil Science of America J., 49:326; Phillips et al., 1985, p.203). Many other strains are known which are highly competitive and effective nodulators. These strains are, of course, considered to be included in the invention.
Transfer of Plasmids to Rhizobium by Triparental Cross
Recombinant plasmids are transferred to the desired host Rhizobium species by a triparental cross, utilizing the helper plasmid pRK2013 (Figurski and Helinski 1979, Proc. Nat. Acad. Sci. U.S.A. 76:1648) as follows. The plasmids were first transformed into E. coli strain, e.g., MM294 (ATCC #33625; 1968, Nature, 217:1110) by conventional methods. Cultures of the recipient Rhizobium strain, E. coli /pRK2013 (which supplies tra and mob functions in trans), and the E. coli strain transformed with a nif recombinant plasmid are mixed on LA agar plates and incubated overnight at 30° C. for conjugation. Such crosses result in the transfer of the plasmids into the host Rhizobium strain by conjugation. Transconjugants are selected on medium containing the appropriate selection for the recipient Rhizobium strain and the nif recombinant plasmids. Plasmid pRK2013 is not stable in Rhizobium and hence is not recoverable from the cross.
Integration
In order to ensure that the constructs described above will be maintained in host cells, and to avoid variation in plasmid retention from strain to strain, it is beneficial to integrate the promoter::gene fusions into the chromosome of an appropriate host rather than maintain them as extrachromosomal elements. Such integration helps to overcome variations observed in plasmid retention, which make it difficult to correlate nifA levels in the bacteroid with changes in plant biomass. Therefore, vectors for the integration or insertion of nif gene fusions into the bacterial chromosome were constructed.
One type of insertion vector is able to cause insertion of DNA at a specific location in the bacterial genome. Such site-specific insertion vectors not only allow transfer of the cloned genes to the bacterial host, but preferably also have some system of instability. One such system is termed marker rescue, where integration of the desired sequences into the chromosome gives rise to a selectable phenotype. An example is the vector pRK290, or a derivative thereof. This vector becomes unstable in the presence of an incompatible plasmid. Thus, marker rescue can be used to select for cells with integrated vector sequences after introducing an incompatible plasmid into the cell containing the vector (see below).
A genomic region of the host chromosome is identified for integration of the desired DNA. Preferably this region is symbiotically silent, i.e., nodule infectiveness, as well as effectiveness, is maintained. The insertion of a desired DNA sequence at a chosen site in the host chromosome should also have little or no effect on the growth of the bacteria, and all metabolic and catabolic activities, other than those specifically altered by the insertion, remain at about wild-type levels.
The vectors preferably contain a “cassette” which comprises all of the elements destined for integration. In this way, the components of the cassette can be replaced with other analogous components using the same vector backbone. The cassette preferably includes (1) a transcriptional promoter fused to a desired gene or genes, particularly genes involved in the enhancement of nitrogen fixation, for example the nifA gene, to form an operon, (2) a selectable marker gene for the selection of integrants carrying the cassette, (3) transcriptional and translational termination signals flanking or, in some cases, intervening between the above described genes to prevent transcriptional read-through from promoters in the adjacent chromosomal DNA and to prevent overexpression of chromosomal genes located downstream of the inserted cassette, and (4) approximately 3-6 kb of flanking DNA sequences homologous to a silent region of the host genome. These flanking sequences, referred to herein as the “homology region”, facilitate the integration of foreign DNA by reciprocal recombination.
Components of the integration vector are described in detail below.
Components of an Integration Vector
Cassette-Carrying Vector
pIC-20H was chosen as the initial cloning vector for construction of the cassette because it is a relatively small plasmid which contains an extensive polylinker. pIC-20H is a pUC derived plasmid with a polylinker containing approximately 16 unique restriction sites located within the β-galactosidase gene (FIG. 18) (Marsh et al., 1984, Gene 32, 482). Any other vector is equally suitable in this invention.
The “homology region”
R. meliloti integration vector
In order to identify a symbiotically silent region of the R. meliloti chromosome, we selected a mutant having a defect in a known pathway that did not appear to suffer in growth or symbiotic associations with plants. The chosen pathway, which is not crucial for cell growth, leads to the degradation of myo-inositol to utilizable carbon sources (Anderson et al., 1971, J. Biol. Chem. 246:5662.). The first step in this pathway is catalyzed by an NAD+-dependent dehydrogenase (inositol dehydrogenase) which is inducible only by myo-inositol. This pathway is not induced by other polyols and should not be active under normal growth conditions, since inositol is not naturally present in soils. The selected mutant in the inositol utilization pathway, designated Rm Ino 1 , was generated by Tn5 insertion mutagenesis of R. meliloti strain 1021 followed by selection for the inability to utilize the sugar myo-inositol as its sole carbon source.
A number of other polyol dehydrogenases are known that are induced by oneor more specific polyols (Primrose and Ronson, 1980, J. Bact. 141:1109) and that are not required under normal growing conditions or when in symbiotic association with a plant. These and other symbiotically silent regions of the chromosome may also serve as suitable sites for the integration of heterologous DNA, and may either encode or regulate an enzyme of the chosen pathway or affect transport of the polyol.
The enzyme inositol dehydrogenase (IDH), which is responsible for the conversion of inositol to a utilizable carbon source, was assayed in Rm Ino − and compared with the activity in R. meliloti 1021, the wild-type parent. No detectable activity was expressed in the mutant strain. However, in plant biomass assays no detectable differences were observed between the mutant strain and the R. meliloti 1021 parent. A DNA region involved in the utilization of myo-inositol (the site of Tn5 insertion) was thus selected as an appropriate site for integration of nif fusions into the Rhizobium genome. This silent genetic region is universally applicable for integrating DNA sequences and should not be limited to DNA sequences of the invention described here.
In order to construct a vector for integration of a DNA segment into a specific genomic location, it is necessary to isolate and clone the homology region. The nifA fusions can then be inserted within this sequence, leaving flanking sequences on either side. Homologous recombination with genomic sequences on either side of the cassette results in its insertion into the genome.
To isolate the selected homology region, a cosmid bank was prepared from R. meliloti DNA by cloning fragments of a partial Sau3A digestion into the BamHI site of pRAR512. PRAR512 was derived from pLAFR1, (Friedman et al., 1982, Gene 18, 289) by inserting a BamHI linker at the EcoRI site which recreates an EcoRI site on either side of the BamHI site. Fragments inserted at the BamHI site can be excised by EcoRI digestion. The cosmid bank was crossed into the Rm Ino 1 strain and individual clones tested for complementation of the Ino − phenotype on media containing myo-inositol as the sole carbon source. Only those Rm Ino 1 mutants carrying the corresponding complementing DNA sequences were able to grow.
Four complementing cosmids were isolated and mapped to localize the Tn5 insert using BamHI and EcoRI restriction endonucleases. The overlap between the four cosmids determined the approximate location of the Tn5 element within the cloned region. Southern blots were performed using the region of Rm Ino 1 DNA containing the Tn5 insert as a probe to confirm the presence and to determine the location in each cosmid of sequences that complement the Ino 1 mutant host. (This probe was prepared from the EcoRI insert of pMW161, constructed by cloning EcoRI fragments of R. meliloti 1021 Ino 1 mutant DNA into pBR327 and selecting for kanamycin resistance in E. coli (Tn5 contains no EcoRI sites and carries the gene for kanamycin resistance)). The location of Tn5 in the Ino 1 mutant was determined by comparing probe hybridization to EcoRI fragments of the cosmid clones with hybridization to the EcoRI fragments of pMW161. Tn5 was found to be inserted within a 6.2 kb EcoRI fragment containing genetic sequences involved in utilization of myo-inositol. This was confirmed by transforming a vector carrying this fragment into the Rm Ino 1 strain and assaying for its ability to complement the Ino 1 phenotype. This fragment is an example of a suitable silent region for use in an insertion vector.
B. japonicum insertion vector
A silent region of the B. japonicum chromosome was discovered within the nif gene cluster. A plasmid carrying the nif cluster, and used as an insertion vector, was obtained from the Boyce Thompson Institute for Plant Research. This plasmid, pREV1000 (Legocki et al., 1984, PNAS, 81, 5806), can generally be used for integration of DNA into the Bradyrhizobium chromosome by homologous recombination between sequences on the vector and sequences in the chromosome. A 3.4 kb region of B. japonicum DNA carried on pREV1000 is interrupted by a unique HindIII site for the convenient insertion of nifA expression cassettes. Insertion of DNA within this region of the B. japonicum chromosome does not appear to affect its growth or nitrogen fixing capabilities.
Promoter::nifA fusions
Fusions of nif promoters to the nifA genes were constructed as described above. These constructs were modified to contain a universal mRNA leader sequence preceding the ATG codon of the nifA gene in order to avoid variations in nifA expression resulting from variations in the 5′ end of the mRNA. By attaching a universal leader sequence to the nifA qene, the transcripts synthesized are identical, independent of the promoter used. The only variable in the fusion, therefore, is the promoter, thus permitting accurate quantitation of promoter strength. To achieve uniformity, it was necessary to make all of the fusions directly between the −1 position of each promoter and the +1 position within the universal leader sequence. An example of such a construction follows.
The R. meliloti nifH leader sequence was chosen because the levels of protein translation from the nifH transcript are high in plant nodules. A synthetic linker (FIG. 17) was constructed which contains the sequence of the nifH leader, and extends from a BglII sticky 5′ end to a Fspl 3′ end. This synthetic linker was used to replace the nifA leader region in pJB182 according to the following strategy. pJB182 was digested with Fspl (FIG. 11) and ligated with the synthetic nifH leader; the plasmid was then digested with BglII to regenerate the BglII end of the synthetic linker and to remove the nifA leader within the plasmid. The BglII ends of the linker and the plasmid were then ligated to create pJB200. The resulting nifH leader::nifA gene fusion is preceded by a unique BglII site for convenient insertion of any promoter fragment that has BglII or BamHI ends.
Following insertion of a promoter fragment, the promoter sequence up to the +1 position of the mRNA is then precisely fused to the +1 site within the nifH leader, using the BssH2 site within the nifH leader and a second site within the promoter fragment. The plasmid is digested with BssH2 and the promoter-leader junction fragment is replaced with a synthetic oligonucleotide that recreates this junction by aligning the +1 position of the promoter with the +1 position within the nifH leader.
The B. japonicum nifD promoter was engineered to precede the nifH leader sequence in pJB200 by the following series of steps. pMW121 (carrying the nifD promoter sequence) was partially digested with SphI in order to cleave only at the site just upstream of the promoter sequence. The site was converted to a KpnI site with synthetic linkers and the plasmid was then redigested with BglII to cleave just downstream of the nifD promoter. The BglII-KpnI promoter fragment of pMW121 was cloned in place of the cat promoter, which precedes the R. meliloti nifA gene, in pJB200. pJB200 was treated by partial digestion with HindIII to cut at the site just upstream of the cat promoter. This site was rendered blunt and converted to a KpnI site with a KpnI linker; the plasmid was then digested with BglII to remove the cat promoter and ligated to the BglII-Kpnl nifD promoter fragment. The resulting plasmid is pMW153. pMW153 is then digested with SphI and BssH2. This fragment is replaced with a synthetic oligonucleotide to create a precise promoter-leader fusion.
The engineering of the B. japonicum nifH promoter:: R. meliloti nifA gene fusion was performed in a similar manner, by removing the nifH promoter from pMW126 as follows. pMW126 was digested with EcoRI, the site was rendered blunt and converted to a KpnI site with a linker; the plasmid was then digested with KpnI and BamHI and the fragment was cloned into BglII and KpnI digested pJB200. (The KpnI site was created by partially digesting pJB200 with HindIII and inserting a KpnI linker.) The resulting plasmid is pMW154. To create a proper fusion between the +1 position of the promoter and the nifH leader, an oligonucleotide was synthesized having BssH2 sites on either end. This fragment was cloned into pMW154 that had been digested with BssH2 at two locations, within the promoter and also within the leader sequence. The resulting plasmid is pMW190.
For convenience, we have prepared all promoter::nifA fusions with flanking KpnI sites because this enzyme does not cut within the R. meliloti nifA gene or any of the promoter fragments used, and is a unique site in the integration vector polylinker sequence.
Selectable Marker
Any desired selectable marker is suitable in this invention. For example, the selectable marker used below is the spectinomycin/streptomycin antibiotic resistance operon obtained from plasmid pHP45Ω (Prenthi et al, 1984, Gene 29:303). pHP45Ω was constructed by isolating the omega fragment (containing the antibiotic resistance genes) from the IncFII plasmid, R100.1 (Jacob et al., DNA Insertion Elements, Plasmids, and Episomes, eds. Bukhari, Shapiro, and Adhya, Cold Spring Harbor, N.Y., 1978, pp. 607-664), and cloning it into a pBR322 derivative. This set of resistance genes is flanked by short inverted repeats carrying the T4 transcription termination and translation stop signals and a polylinker sequence. The region can be removed from pHP45Ω on a 2.0 kb fragment by digestion with any of a number of restriction enzymes. For construction of the vector of this invention, we isolated the EcoRI restriction fragment and cloned it into EcoRI digested pMW152 (see following section) to create pMW155 (FIG. 18 ).
Termination Signals
Transcription termination signals are well known in the art and any desired signal is suitable in this invention. For example, a 1.1 kb fragment carrying the T1/T2 transcriptional terminators from the rrnB operon of E. coli (Brosius et al., 1981, J. Mol. Biol. 148:107) was obtained from the vector pEA300 (Molecular Cloning, A laboratory Manual 1982, eds. Maniatis, Fritsch and Sambrook) and cloned into SmaI digested pIC-20H, creating pMW152 (FIG. 18 ).
The promoter::nifA gene fusions inserted into the KpnI site of the pIC-20H are flanked by transcription termination signals (from the omega fragment and T1/T2) to prevent transcriptional read-through into the adjacent Rhizobium genomic DNA. It is preferable to use different flanking termination signals so as to avoid a recombination event within the cassette.
Process of Integration
Once the dassette is constructed, any suitable vector is used to transfer the cassette into the desired host. A number of restriction sites are available in the polylinker sequence for removal of the cassette from pIC-20H. Integration is induced by standard procedures. The following is an example demonstrating the use of pRK290 (Helinski, U.S. Pat. No. 4,590,163) as the cloning vector.
The cassette, containing the B. japonicum nifA promoter:: R. meliloti nifA gene fusion and the omega fragment is removed from the pIC-20H based vector on an XbaI fragment (the EcoRV site in the pIC-20H polylinker was converted to an XbaI site) and cloned into the SpeI site of the pRK290 derivative, pMW184. (pMW184 was derived from a pRK290 based plasmid containing the 6.2 EcoRI inositol fragment by first digesting with HpaI and Bal 31 to remove the Tn5 sequence, then inserting SpeI linkers to create a unique site for cloning of the integration cassette.) This construct, which now contains the cassette flanked by the homology region, and an incompatible plasmid, e.g., pJB251, carrying the gentamycin resistance selectable marker gene, are introduced into the R. meliloti host RCR2011. (pJB251 was derived from pPH1 (Hersh et al., 1984, Plasmid 12:139) by doing a partial HindIII digestion to delete the spectinomycin gene and then selecting for gentamycin r , and screening for spectinomycin s .) Recipients are selected for expression of both spectinomycin and gentamycin resistances. Since the two plasmids are incompatible, these genes will only be expressed simultaneously if the cassette has integrated into the chromosome or if the vectors have recombined with each other. To distinguish between the two cases, the transformants are screened for tetracycline sensitivity, i.e., loss of the pRK290-derived vector, and for the lack of ability to grow on myo-inositol as a carbon source, indicating that the cassette has integrated into the genome. The DNA of the integrants is then analyzed by conventional procedures to confirm that integration has occurred.
The recipient host is subsequently cured of the pJB251 plasmid by allowing the strains to nodulate alfalfa, re-isolating the bacteria and screening for those that were spectinomycin resistant and gentamycin sensitive. These isolates are then tested on alfalfa to determine the effect on plant biomass.
Microorganisms and Legumes
The species of modified nitrogen fixing bacteria employed depends on the plant species to be inoculated. Generally, it is preferred that the same bacterial species which naturally associates with the plant species be employed as the host species for the vector of the invention. For example, where the legume is alfalfa ( Medicago sativa ), the modified host bacterium is preferably R. meliloti; where the legume is soybean ( Glycine max ), the bacterium is preferably R. japonicum; where the legume is the bean Phaseolus vulgaris, the bacterium is preferably R. phaseoli; and where the legume is clover, the bacterium is preferably R. trifolii. In addition to Rhizobium species, the invention can be applied to other natural nitrogen-fixing bacterial species, as well as to microorganisms into which nitrogen fixing genes have been inserted via recombinant DNA techniques.
Inoculation of Plants
Inoculation of plant seeds with recombinant Rhizobium can be performed by the following procedure, (See “A Manual for the Study of Root Nodule Bacteria”, ed. Vincent, 1970, Blackwell Scientific Publishers, Oxford and Edinborough, pp.113-131 for general procedures.). Raw seeds are sterilized in a 10% solution of Sodium Hypochlorite for 20 minutes followed by extensive rinsing with distilled water. Seeds are then spread into a pot containing sterilized vermiculite and placed in the dark for 4 days to germinate. To prepare the inoculant, YM+ media containing the appropriate antibiotics is seeded with Rhizobium cells and grown for 30 hours. The culture is centrifuged to pellet the cells and resuspended in sterile distilled water to a final concentration of about 1×10 9 cells/ml. The cells are diluted 125× into sterile mineral salts and used to inoculate the 4-day old germinated seedlings. (The final concentration of Rhizobium in each pot is approximately 1×10 7 cells/ml). The plants are watered appropriately, including once per week with mineral salts. After 4 weeks the plants are harvested.
Commercial Uses of Rhizobia
Product form
Inoculants of rhizobial cultures are used commercially to increase the yields of legume crops and are available in several forms. In one form, cultures are absorbed on a carrier of peat or clay, then applied to seeds as a very thin coating. If mixed with lime and binder, legume seeds become covered with a relatively thick coating, adding up to 50% to the weight of the seeds.
In the second method, cultures are available in a liquid form or preabsorbed on peat for application during planting. Finally, Rhizobia can be absorbed on large particle size peat for direct application in a seed furrow of a planter box.
Production
Rhizobium cultures are grown in standard aerobic fermentations and are then generally combined with a carrier of fine powdered peat or clay. This is done by mixing a volume of cell suspension into a specially selected grade of peat or clay, and allowing a certain amount of time for absorption during which the cells continue to grow on the carrier. Cell numbers might increase ten-fold in the peat and with proper storage, these cultures can be held up to nine months before use.
Deposits
Plasmids/pJB111 was deposited in the American Type Culture Collection, Rockville, Md. on Nov. 21, 1984. The above deposit has been given ATCC Accession No. 39931.
Applicants' assignee, BioTechnica International, Inc., acknowledges its responsibility to replace this culture should it die before the end of the term of a patent issued hereon, 5 years after the last request for a culture, or 30 years, whichever is the longer, and its responsibility to notify the depository of the issuance of such a patent, at which time the deposit will be irrevocably made available to the public. Until that time the deposit will be made available to the Commissioner of Patents under the terms of 37 CFR Section 1.14 and 35 USC Section 112.
Other embodiments are within the following claims. | Method for increasing the rate of conversion of atmospheric nitrogen into ammonia in a microorganism of the genus Rhizobium, by increasing the intracellular level of an activator protein which is capable of activating the transcription of DNA of the microorganism encoding one or more proteins capable of effecting such conversion in the microorganism. | 2 |
FIELD OF THE INVENTION
This invention relates to body support structures and, more particularly, to multi-laminar mattresses, cushions, and lumbar support systems composed of a plurality of discrete chambers sealed to a fluid flow control panel which provides fluid flow conduits for selective inflation of the chambers.
BACKGROUND OF THE INVENTION
Many inflatable mattresses and cushions are used to provide added comfort and support to individuals who are in a sitting or supine position for a prolonged period of time. Some of these mattresses and cushions are adapted to be placed upon a hospital bed or upon wheelchair seats to reduce the likelihood of developing bedsores.
Inflatable air mattresses adapted to prevent bedsores are disclosed by Chamberland in U.S. Pat. No. 4,896,389 and Afeyan in U.S. Pat. No. 4,914,771. Each mattress is formed of two sheets of plastic material comprising of a plurality of elongated pillows adjacent to and parallel to each other which are formed by folding the upper sheet and a base portion having two air distribution channels or plenums disposed along the full length of both sides of the mattress. The ends of the pillows communicate with the plenums. A pumping means provides air flow to the plenums via a tubular hose to inflate all pillows of the mattress to a constant uniform pressure.
It is known in the art to use inflatable mattresses or sheets having separate zones of pillows which can be independently pressurized to reduce the likelihood of developing bedsores. Each zone is alternately inflated and depressurized to vary the load upon the portion of the person's body in contact with the mattress. At present, such mattresses generally employ a number of discrete tubular hoses and fittings connected to each of the pillows to be alternately inflated and deflated. This construction, however, is cumbersome to use and difficult and time consuming to manufacture.
An inflatable sheet disclosed by Grant in U.S. Pat. No. 5,263,211 is another example of the use of independent zones of cells that are alternately inflated and deflated. The inflatable sheet comprises two sheets of plastic material sealed together to form two independent sets of interdigitated fluid cells. The arrangement of the cells and the dimensions thereof are limited because the cells act as both the cushioning means and the conduit to supply air to the cells.
SUMMARY OF THE INVENTION
It is the principal object of this invention to provide an inflatable multi-laminar structure with an economical means for selective inflation of the chambers of the structure.
It is another object of this invention to provide an inflatable multi-laminar structure constructed to enable the chambers that form the structure to be inflated in various sequences, patterns or configurations.
According to the present invention, a unitary fluid flow control panel of a generally planar, multi-laminar construction is composed of synthetic plastic layers sealed together at predetermined locations to provide for a plurality of predetermined fluid flow conduits for connection to a variable pressure source for the fluid, at least one layer of the panel also being provided with a predetermined pattern of apertures therethrough to provide fluid communication with at least one of the conduits. The panel has sealed thereto in generally coplanar relationship, an inflatable structure including a plurality of fluid orifices adapted to be disposed in registered relation with the apertures. A release material is selectively disposed in a preselected pattern on an interior surface of the panel to provide conduit paths and to prevent sealing of the interior surfaces of the conduits when sealing of the inflatable structure onto the panel.
The above and other objects and advantages of this invention will become more readily apparent when the following description is read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cushion in an inflated condition of the type which embodies the present invention;
FIG. 2 is a cross-sectional view taken along line 2--2 of the cushion of FIG. 1;
FIG. 3 is a cross-sectional view taken along line 3--3 of the cushion of FIG. 1;
FIG. 4 is a top plan view of the cushion of FIG. 1 during a step in the manufacture thereof;
FIG. 5 is a cross-sectional view taken along line 5--5 of the cushion of FIG. 4;
FIG. 6 is an exploded perspective view, illustrative of the method of manufacture of the cushion of FIG. 1;
FIG. 7 is a top plan view of an alternative embodiment of the cushion of FIG. 1;
FIG. 8 is a cross-sectional view taken along line 8--8 of the cushion of FIG. 7, and
FIG. 9 is a cross-sectional view taken along line 9--9 of the cushion of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An inflatable cushion 8 of the type embodying the invention is illustrated in FIG. 1 and formed entirely of flexible thermoplastic material, such as polyurethane, polyvinyl chloride, or the like. As shown, the cushion 8 comprises a plurality of discrete, contiguous and parallel chambers 10 and 10' secured at 12 to a preformed planar fluid flow control panel 14.
The control panel 14, as shown, generally includes two independent conduits 30 and 30' adapted for alternately inflating and deflating the inflatable chambers 10 and 10' sealed thereto. Each of the conduits 30 and 30' extend longitudinally along the control panel 14 generally parallel to opposite side edges 15 and 16 thereof. A pumping means (not shown), adapted to alternately provide fluid under pressure to one of the conduits 30 and 30' while substantially simultaneously exhausting the fluid from the other of the two conduits 30 and 30'. Thereafter, in a predetermined time sequence, the cycle would be reversed so that if the first cycle involved supplying high pressure fluid to conduit 30' while exhausting the fluid by connection of conduit 30 to a vacuum source, in the next cycle, conduit 30 would be connected to the high pressure side of the pump and conduit 30' to the vacuum side thereof. Referring to FIGS. 2 and 3, the conduits 30 and 30' are in fluid communication with the chambers 10 and 10' through apertures 38 and 38' disposed in the upper sheet 34 of the control panel 14 and a fluid orifice 29 and 29' disposed through the lower wall portion 22 of each chamber. The chambers 10 and 10' are sealed to the control panel 14 such that the orifices and apertures are sealed in registered relation to each other to provide the means for fluid communication therebetween. The apertures 38 and 38' are disposed in the control panel 14 in a predetermined pattern (see FIG. 6) such that the each conduit 30 and 30' communicates with every other chamber. The features of this embodiment will hereinafter be referenced by their generic number.
No matter the complexity of the number and locations of the fluid conduits 30 and apertures 38 required to communicate with the chambers, the control panel 14 may be easily changed by simply varying its sealing pattern. The flow control panel 14 allows for the chambers 10 to be disposed in a variety of arrangements or patterns on the control panel 14 with a plurality of conduits 30 disposed therein to provide a simple, cost effective means to selectively interconnect predetermined groups of chambers.
Another important aspect of this invention, as best illustrated in FIG. 5, is that the cushion 8 is assembled as a planar structure to thereby reduce the time and cost to fabricate the cushion. Referring to FIG. 6, this, in part, is accomplished by coating the inner surface 53' of the chambers 10 with a release or barrier material 56 to prevent the inner surfaces thereof from sealing together when the preformed chambers are sealed to the preformed control panel 14. In addition, the inner surface 60 of layer 36 is coated with release material 31, as shown in FIG. 6, to prevent the sealing together of the opposed surfaces of layers 34 and 36 when the chambers 10 are sealed to the upper surface 62 of layer 34 of the flow control panel.
The preformed, inflatable chambers 10, as shown in FIG. 6, may be formed by a lower sheet 22 and an upper sheet 53 sealed together about their peripheral edges to form, when inflated, a generally elongated fluid chamber of oval cross-section (FIG. 2). The inner surface 53' of the upper layers is coated with a barrier material 56. Each chamber 10 has at least one fluid orifice 29 disposed at a predetermined position in the lower portion 22 of the chamber to provide fluid intercommunication between the chamber 10 and a conduit 30 of the flow control panel 14. Mounting tabs 24 (FIGS. 4 and 6) extend outwardly at opposite ends of the lower layer 22 of the chambers with eyelets 26 disposed therein for temporarily securing the chambers in place to the flow control panel 14 during the sealing and assembly process, to be described hereinafter. A perforation or score line 28 disposed between the tab 24 and the lower layer 22 of the chamber 10 provide easy removal of the tab once the chamber is permanently sealed to the flow control panel 14.
The flow control panel 14 provides a planar surface for securing the chambers 10 thereto and in fixed contiguous relation to each other while providing fluid distribution conduits 30 of planar configuration, except when actually in use to inflate the chambers, between an inflation opening or valve means 32 and the chambers.
In the preferred embodiment shown in FIGS. 5 and 6, the flow control panel 14 comprises an upper sheet 34 and lower sheet 36 of thermoplastic material, in stacked edge-to-edge relationship and sealed together with release material 31 therebetween to define a plurality of independent conduits 30 which may be arranged in any predetermined pattern for interconnection of various groups of chambers 10. It should be recognized by one skilled in the art that the control panel 14 may be formed of a single, folded sheet of material.
The inner surface 60 of the lower sheet 36 of the flow control panel 14 is coated with a release material 31 over the area that will define the conduits 30 to prevent the inner surfaces of the conduits from sealing or adhering together so as to not block or limit fluid flow therethrough. The release material 31 prevents sealing of the inner surfaces of the conduits when the chambers 10 are sealed to the outer surface 62 of the upper sheet 34 of the flow control panel 14 at 12. In addition, the release material overcomes the tendency of the inner surfaces of the sheet material 34 and 36 from blocking or adhering together when the control panel is deflated for long periods of time. In the alternative, the inner surface of the conduits 30 may simply be coated at locations within the conduits disposed below the seal 12.
The upper sheet 34 of the control panel 14 has a plurality of fluid communication apertures 38 disposed along the conduits 30 in a predetermined pattern. The chambers 10 are sealed to the control panel 14 about the orifices 29 which are disposed in registered relationship to the apertures 38. The apertures 38 are arranged such that each independent conduit 30 communicates with every other chamber 10, as best shown in FIGS. 1 and 4, and which allows for the two independent groups of chambers to be inflated at different pressures and/or at different times. Moreover, as heretofore described, the two groups of chambers 10 and 10' may be alternately inflated and deflated using a pumping means (not shown) connected to the inflation openings or valve 32 and 32'.
The flow control panel 14 also includes perforation or score lines 40, (FIGS. 4, 5 and 6) adapted to be readily separated, that longitudinally extend along opposite side edges 37 thereof to define two registration strips 42. In the embodiment shown in FIG. 4, a plurality of equi-spaced eyelets 44 are longitudinally disposed along the length of each strip. The longitudinal distance between the eyelets 44 determine the position or lateral spacing between adjacent chambers.
Referring to FIG. 4, the eylets 44 of the control panel 14 and the eyelets 26 of the mounting tabs 24 of the chambers 10 are adapted to engage a plurality of registration posts or pins 49 extend from a planar surface 47 to temporarily secure and properly position the chambers 10 and the flow control panel 14 in coplanar relationship during assembly thereof.
Referring to FIG. 6, one method of manufacturing the cushion 8 depicted in FIG. 1 is to independently prefabricate the chambers 10 and flow control panel 14 and then, simply assemble the preformed chambers and flow control panel together, as a coplanar structure, to form the operable cushion 8. To fabricate the flow control panel 14, both the upper and lower sheets 34 and 36 of thermoplastic material may be perforated or scored to define the registration strips 42 that longitudinally extend along the opposing sides 37. The eyelets 44 disposed therein are cut or punched out. The apertures 38 in the upper sheet 34 are then cut or punched out in a predetermined pattern. The inner surface 60 of the lower sheet 36 is coated with a release material 31, as described hereinafter, over the area that defines the conduits. The sheets 34 and 36 are then stacked in edge-to-edge relationship and sealed around the edges 46 (FIGS. 4 and 5) of the conduits 30 using RF energy. In the alternative, the sheets of the control panel 14 may be laminated together by heat-sealing the entire panel whereby the sheets seal together except for the areas coated with release material 31 to thereby form the conduits 30. Heat-sealing the entire panel 14 allows for the conduits 30 to be rerouted by simply changing the pattern of the release material.
Each of the chambers 10 are formed by preferably die-cutting each layer of sheet material to the desired shape. It should be recognized by one skilled in the art that the chambers may be of any shape, such as circular, oval, elliptical or polygonal, without departing from this invention. The lower portion 22 of each chamber includes a fluid communication orifice 29 and mounting tabs 24 which are separated from the chamber 10 by perforation or score lines 28.
The release material, as discussed above, may be applied, such as disclosed in my earlier U.S. Pat. No. 5,022,109, by conventional printing techniques, such as silk screening, rotogravure or flexographic process. Preferably, the coatings are applied as a composition in a liquid dispersion medium of an organic solvent or water base with a dispersed phase of freely divided microscopic particles of a polyethylene, a polytetrafluoroethylene (Teflon) or silicone on the order of five microns in diameter. With the release material firmly bonded to the sheets, the polyethylene, Teflon or silicone particles thereof will inhibit the sealing of the coated areas in the abutted portions of the two sheets engaged by the sealing dies.
After the control panel 14 and chambers 10 have been formed, the control panel is then fitted upon a flat planar surface 47 that has a plurality of registration pins 49 of sufficient height to extend through the eyelets of the registration strips 42 and the eyelets in the tabs 24. In this way, the chambers 10 will be positioned accurately on the outer surface 62 of the upper layer 34 of the flow control panel 14. Each tab 24 may then be spot-sealed to the registration strip 42 at 50, as shown in FIGS. 4 and 5 between the eyelet 26 and the perforations 28. After sealing the chambers 10 to the control panel as shown at 12 of the drawings, they are then permanently secured to the flow control panel 14 with the fluid orifices 29 of the chambers 10 disposed and registered in sealed relation with the fluid apertures 38 of the fluid control panel.
After such sealing operation, the registration strips 42 may be readily removed from the assembly by tearing along the perforated lines 40 and the superimposed score lines 28 of the mounting tabs 24.
Referring to an alternative embodiment of the control panel 14, is shown in FIGS. 7-9 and comprises a plurality of elongated chambers 10 and generally circular chambers 80 sealed to the control panel.
The control panel 14 may comprise three or more layers or sheets of thermoplastic material sealed in stacked edge-to-edge relationship to form a plurality of tiers 77 and 78 which provide conduits therebetween. This embodiment comprises three sheets 70, 71, and 72 sealed together to form an upper tier 77 and lower tier 78, as best shown in FIGS. 8 and 9. The upper and intermediate sheets 70 and 71 form the upper tier and provides conduits 74 and 75 therebetween. The intermediate sheet 71 and lower sheet 72 form the lower tier 78 and provide conduit 76 therebetween. Conduit 76 laterally traverses conduits 74 and 75 which longitudinally extend along the sides of the control panel 14. The conduit 76 extends transversely across the panel 14 intermediate the ends of the longitudinal conduits 74 and 75. The lower conduit 76 communicates with the chambers 80 via apertures 79 disposed in the upper and intermediate sheets 70 and 71 to provide fluid communication between the conduit 76 and chambers 80.
Although the fluid flow control panel 14 provides fluid communication to the chambers 10 of an inflatable body support structure, it should be apparent to one skilled in the art that the flow control panel be used to inflate a plurality of chambers or bellows sealed thereto to selectively actuate or manipulate valves or switches for various control applications.
Although the invention has been shown and described with respect to an exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions, and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention. | A control panel for an inflatable structure includes a multi-layer planar fluid flow control panel sealed together at predetermined locations to define at least one fluid flow conduit with at least one layer of the panel having a plurality of apertures located in a predetermined pattern that communicate with the conduits. A plurality of discrete, inflatable chambers are sealed in planar orientation to the upper surface of the control panel to form the structure. The apertures of the panel are sealed in registered relationship with the fluid orifices to thereby permit fluid communication between the chambers and conduits of the control panel for selective inflation and deflation thereof. The interior surface of the control panel and chambers is selectively coated with a release material to prevent closure of the conduits and enable coplanar sealing of the chambers onto the panel about the perimeter of the apertures and orifices when disposed in registered relation. | 1 |
The present invention is concerned with a nonimaging concentrator for light. More particularly, the invention is concerned with a solar energy concentrator or collector having an absorber concentrically disposed with a glass housing enabling nonimaging light concentration, such as a evacuated cylindrical reflector tube. This absorber geometry also includes a gap loss reduction V groove which is positioned in a complementary manner relative to a wedge shaped heat conductor fin coupled to the absorber.
Nonimaging concentrators and their advantages are well known in the art (see, for example, U.S. Pat. Nos. 3,957,031; 4,002,499; 4,003,638; 4,230,095; 4,387,961; 4,359,265; and 5,289,356 incorporated by reference herein). In these previous methodologies, the device is constructed using a given absorber shape, usually a cylindrical tube, and then the appropriate nonimaging reflector is designed. This emphasis was therefore primarily on developing new reflector designs to optimize collector efficiency. There has recently been made available new types of high performance absorber materials which can even be disposed on flexible substrates. These absorbers have an absorbtance typically greater than 90% over the solar spectrum, while the hemispherical emittance at operating temperatures is quite low.
It is therefore an object of the invention to provide an improved nonimaging solar collector and method of use thereof.
It is another object of the invention to provide a novel nonimaging solar collector having an absorber concentrically disposed within a glass housing enabling nonimaging light concentration.
It is a further object of the invention to provide an improved nonimaging solar collector having an outer housing and a concentrically disposed tubular absorber with a radially coupled wedge shaped heat conduction fin.
It is also an object of the invention to provide a novel nonimaging solar collector having a cylindrical reflector and tubular absorber coupled to a conically shaped cross sectional heat conductor.
It is yet another object of the invention to provide an improved solar collector having an absorber concentrically disposed within a reflector and coupled conical cross section heat conductor.
It is still a further object of the invention to provide a solar collector utilizing absorbers having high efficiency and which are disposable on flexible substrates designed to optimize collection properties.
It is another object of the invention to provide a method and article of manufacture for providing high solar collector efficiency with a concentric heat exchange channel design which enables easy construction and assembly without need for solar tracking drives.
Other objects and advantages of the invention will be apparent from the detailed description and drawings described hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a prior art solar collector with a flat fin conductor;
FIG. 2 illustrates a prior art nonimaging solar collector of 35° acceptance angle with an absorber disposed noncentrically within a cusp shaped reflector;
FIG. 3A illustrates a cross-sectional view along 3A--3A on FIG. 3D of a nonimaging solar collector having an absorber concentrically disposed within a cylindrical reflector with a V-groove gap loss suppresser and the absorber further includes a coupled heat conductor fin having a conically shaped cross section;
FIG. 3B shows a ray trace for the collector of FIG. 3A; FIG. 3C illustrates a perspective view of the solar collector of FIG. 3A; and FIG. 3D illustrates a plot of thermal performance of the 40° V-groove collector of FIG. 3A and the 35° ICPC collector of FIG. 2 when displaced from ideal positioning;
FIG. 4 illustrates another version of the collector of FIG. 3 but with increased angle of acceptance;
FIG. 5 illustrates a variation on the solar collector of FIG. 3 but without the V-groove gap loss suppresser element;
FIG. 6A illustrates a nonimaging collector with a concentric tubular absorber and raised reflector contour providing a five degree acceptance angle and FIG. 6B illustrates a ray trace for the collector of FIG. 6A;
FIG. 7 illustrates angular acceptance properties of the collector of FIG. 6.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A nonimaging solar collector constructed in accordance with the invention is shown in FIGS. 3-6 and indicated generally at 10. Several prior art collector designs are shown for comparison in FIGS. 1 and 2. The prior art collector 12 of FIG. 1 has heat conductor fins 14 and 16 which both radiate heat so that thermal performance is poor at temperatures above about 100° C. Prior art nonimaging collector 18 of FIG. 2 has relatively good thermal performance at elevated temperatures, but absorber 20 is noncentrically disposed and requires manufacture of a somewhat intricate reflector geometry 22.
The inventive nonimaging solar collector 10 includes an outer glass tube housing 24 which is transparent, allowing entry of light rays 26 (see FIG. 3B) into the evacuated interior of the housing 24. The housing 24 is shown as cylindrical in shape but can take on other geometries suitable for the functions described herein. The light rays 26 either directly strike absorber tube 28 or reflect from reflector surface 32 to impinge upon the absorber tube 28 and thereby concentrate the collected light. In the preferred embodiment this absorber tube 28 can be shapes other than shown in the figures but is concentrically positioned relative to the housing 24. The absorber tube 28 further can include a wedge shaped heat conductor 30 (see FIG. 3C) which in cross-section collectively appears with the absorber tube 28 as an "ice cream cone" geometry, as noted in FIGS. 3A, 3B, 4 and 5.
In a preferred embodiment (see FIGS. 3, 4 and 5) reflector surface 32 includes a gap loss reduction V-groove 34. This groove 34 suppresses energy absorption gap loss which would otherwise occur when there is a space between the reflector surface 32 and the wedge shaped heat conductor 30. In FIG. 3A the angle of acceptance for the absorber is about 40° which would make the collector 10 suitable for east-west orientation without need of any solar tracking mechanism. This particular angular acceptance with the associated V-groove 34 provides excellent tolerance for vertical positioning errors in placement of the absorber 30, as well as good tolerance for horizontal displacements (see FIG. 3D).
The collector 10 of FIG. 4 has a smaller radius of curvature for the reflector surface 32, resulting in a wider, 70° angle of acceptance. This embodiment would allow the collector 10 to be suitable for north-south or east-west orientation without need of any solar tracking device.
The collector 10 of FIG. 5 is the limiting case of the embodiments of FIGS. 3 and 4 where the radius of curvature of the reflector surface 32 is coincident with the inner surface of the glass tube housing 24. This embodiment has an acceptance angle approaching 90°. This form of the collector 10 further simplifies the construction procedure for manufacture of the collector 10.
In the embodiment of FIGS. 6A and 6B, the reflector surface 32 has a relatively large radius of curvature such that the angle of acceptance is about 5° and would require some crude solar tracking device, operative either continuously or intermittently. This design includes a small cusp arising from the small angle of acceptance. The thermal performance is quite good at elevated temperatures. FIG. 7 shows the efficiency versus incident angle of the embodiment of FIG. 6 for concentration factors of two, three, four and five with reflection or Fresnel losses ignored. Concentrations of about four are achieved with efficient 5° acceptance properties.
Thermal performance for the illustrated embodiments of the figures are shown in Table I below. Calculations have been performed based on an average meteorological year in Albuquerque, N.M. The emittance assumed for the absorber is 0.05 at T=100° C. and an absorbtance of 0.95.
TABLE I__________________________________________________________________________Thermal Performance 5° ICPC 40° ICPC 40° VG 70° VG 90° Circle Flat FinProperty (FIG. 6) (FIG. 2) (FIG. 3) (FIG. 4) (FIG. 5) (FIG. 1)__________________________________________________________________________Concent. 4.00 1.47 1.16 1.01 0.94 0.46Gaploss ˜0% 0% 0.25% 0.5% 4% 4%Thermal 82.4 62.6% 67.4% 70.1% 68.5% 64.6%Efficiency(T = 100 C.)Thermal 79.7 57.6% 61.0% 62.7% 60.6% 50.8%Efficiency(T = 150 C.)Thermal 76.1 50.8% 52.2% 52.5% 49.8% 32.8%Efficiency(T = 200 C.)Thermal 71.1 42.0% 40.8% 39.3% 35.9% 12.7%Efficiency(T = 250 C.)North South Required No No Yes Yes YesOrientationAllowedNeed Yes Yes Yes Yes No NoReflectorInsertReflector Yes Yes Yes Yes Yes NoSilveringRequiredConcentric Yea No Yes Yes Yes YesGlass-to-Metal SealsShaping of Yes Yes No No Yes YesGlass TubeAllowedActive Yes No No No No NoTrackingRequired__________________________________________________________________________
In construction of the collector 10, it is also preferable to utilize several classes of high performance solar absorber coatings on the absorber tube 28 and the heat conductor 30. Coatings can be, for example, cermets having a very low emittance (about 0.02 at 20° C.) and a high absorbtance (about 0.92) over the solar spectrum. Cermets are conventional materials which have layers of dielectric materials which contain a particular fraction of metal composition disposed on a metal reflector layer having an anti-reflection coating. The top layers have lower metal fractions in the dielectric material than those layers below them. The higher metal fraction layer at the bottom absorbs more energy because visible light passes through the top layers easily. The emission of black body radiation (>2 mm wave length) is however reflected by the cermet dopant quite efficiently. Thus, emission of radiation from the bottom layer is trapped inside the absorber material, and only the low doped top layer radiates away heat. The graded metal content increases the amount of atoms seen by the incoming light so more is absorbed and also reduces the number of atoms which can radiate away heat.
Another class of materials useful as absorbers are certain ceramics which can easily be made using vacuum deposition. For example, conventional layers of TiN x O y and SiO 2 /TiN x O y can be deposited onto an aluminum or copper substrate until a set amount of accumulation has been measured. Both of these types of materials have a TiN x O y layer about 53 nm thick on a substrate. The second type of absorber material has a 90 nm layer of SiO 2 added. The thermal properties of such materials are very favorable for use as solar absorbers. On copper substrates an absorbtance of 0.90 or higher can be achieved with an emittance of 0.06 at T=200° C. while aluminum substrates achieve absorbtance as high as 0.95 and an emittance of 0.03 at T=100° C.
The above described preferred embodiments utilize a concentrically disposed absorber tube within a cylindrical reflector housing which has been evacuated. The absorber tube further includes a wedge shaped heat conduction fin coupled to the absorber, and preferably includes an absorber layer (absorbtance greater than 0.90) with low emittance (less than about 0.05) to achieve a very efficient solar collector. The simplicity of this basic design allows easy manufacturing, reducing construction costs thereby making solar collector usage more practical.
Further advantages and features of the invention will be appreciated by reference to the claims set forth hereinafter. While preferred embodiments have been described, it will be clear to those of ordinary skill in the art that changes and modifications can be made without departing from the spirit and scope of the invention in its fullest aspects. | A nonimaging solar collector. A method and article of manufacture of a solar collector includes an outer housing transparent to light, a reflector element positioned within the outer housing, an absorber concentrically disposed relative to the outer housing, and a heat conduction fin coupled to the absorber and having a wedge shape which tapers to a smaller thickness as a function of increasing radial separation from the absorber. | 5 |
[0001] This is a non-provisional application claiming the benefit of provisional application Ser. No. 60/219,197 entitled, User Interface For Online Product Configuration and Exploration, filed Jul. 19, 2000, which is hereby incorporated by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates generally to graphical user interfaces for product configuration and exploration. More specifically, the present invention relates to a system and method for integrating a variety of search information and generating multiple views of a product and/or product collection to facilitate accurate and effective access of information over an electronic network.
[0004] 2. Description of Related Art
[0005] The worldwide acceptance of the Internet represents a turning point in electronic business by providing an easy-to-use technological solution to the problem of information publishing and dissemination. As the electronic business market grows, more and more customers are able to get instant access over the World Wide Web to information regarding various products, services, and even their own words. In addition, customers can compare and shop globally around the clock.
[0006] Access to such a plethora of information facilitates comparison shopping, which means a business customer could very easily change suppliers. As a result, customer loyalties have become harder to win. For many companies, the challenge is becoming how to provide high quality personalized customer services to not only retain customers but to attract new customers as well.
[0007] Personalized customer services can best be realized by establishing trusted relationships between a business and its customers. In such a relationship, customers will always be able to count on the customer support center for satisfying their needs. This, however, requires investment in staffing and retaining sufficient numbers of experienced human agents to staff customer support centers. Given the fluctuating nature of customer requests, it is extremely difficult for any business to control the personnel cost of offering such services.
[0008] The World Wide Web is a powerful medium which makes it possible to offer such personalized services with a minimum use of personnel resources. Various companies offer software which enables online customers to obtain product information and conduct transactions without the involvement of human agents. Despite the advancement of personalization and knowledge management technologies however, it is still difficult for customers to quickly access relevant and accurate information, whether it is related to products or services, due to an often overwhelming amount of information provided. Existing solutions are useful only when the navigation structure is simple and visitors are familiar with the content. Usually, the problem is not in the availability of relevant information but, rather, its accessibility. Whether it is a prospective customer interested in product information, or an existing customer accessing online help and/or service information, their primary goal is to access relevant and accurate information as quickly as possible.
[0009] Most business web sites offer three independent modes for accessing product information: browsing, query, or human assistance modes. In the browsing mode, navigation aids such as trees, tabs, and lists are provided and the user is expected to find his way through the given navigation structure. This is possible only when the user understands the product line. In the query mode, the user enters a query and is then presented with a list of relevant documents in the order of their relevance. If the user is lucky, some of the top documents in the list may be relevant to his/her needs. If not, s/he may be forced to either wade through a long list of the remaining documents or simply give up. Finally, some web sites may offer a “Call Expert” button to access a human expert, but the user must explain everything from the beginning in order to be assisted, which is time-consuming and only adds to his/her frustration.
[0010] Once a user decides which product to buy, most business web sites offer only standard configurations of each product to try to simplify the presentation of information for users. Some sites offer a product configurator for sophisticated users, however, in this case, users are expected to provide an answer for each of a series of detailed questions. Often several rounds of trial and error are required before users can finalize their product configuration. A typical example of this online product configurator are reservation systems offered by online travel agencies, in which users are expected to know detailed information in advance such as the date and time of travel, destinations, etc., in order to finalize their travel itinerary.
[0011] The above problems due to inefficient and ineffective product exploration and product configuration cannot be solved by current personalization technologies based on information such as customer profiles, community statistics, and customer records. These personalization features create dynamic customized web pages, and provide personalized navigation support. However, they offer little or no help in situations where users only have vague or ill-defined ideas about what they would like to buy, when they do not completely comprehend the product line, or when they are not familiar with the terminology used by the business. In addition, although a particular web site may be personalized to some extent for a particular user, there is often still much more information (for example, about products) than a typical user needs.
[0012] Accordingly, an efficient and effective data search technique for providing improved product exploration and configuration to provide users with relevant and accurate information, is highly desirable.
SUMMARY OF THE INVENTION
[0013] The present invention provides an improved user interface for product exploration and product configuration in which a seamless integration of browsing, query, and human assistance is provided which is customized to the knowledge level of each individual user.
[0014] Advantageously, since product information is available via multiple views in the present invention, a user is able to browse using views appropriate for his/her needs. Each view may be represented by a tab on the user interface. Each tab may be comprised of various colors according to the relevance of the documents under each tab (view) with respect to the entered query. In addition, relevance indicators are provided for each sub-category under a view, which the user can use as a guide to quickly navigate to a sub-category which has the most relevant documents.
[0015] If the user is still not familiar with a website's layout, s/he can type in a query. The system then orders documents based on relevance to the entered query. Unlike commercial search engines, a system according to the present invention utilizes the structure of indexes and the user's profile and context information, to produce effective results. For example, a user may indicate in his/her profile that certain areas of information are not of interest, and the system will display any documents under those areas in, for example, a de-emphasized manner. Thus, users avoid looking at documents which are not consistent with their profile.
[0016] Overall, a user interface for product exploration and configuration according to the present invention: 1) offers different users different sets of views, each of which provides a unique and independent perspective of the product line or product information, 2) maps information from one view to other views to facilitate selective refinement while browsing, and 3) summarizes the intention and knowledge level of users to human agents, thus providing seamless transition from self-help mode to agent-assistance mode without the need for users to explain everything from the beginning.
[0017] A user interface according to an aspect of the present invention includes a hypertext browser coupled with a multi-view product browser and a query interface. The hypertext browser is used to display search/browsing results as well as to browse product catalogs or an information space such as, for example, the World Wide Web.
[0018] The multi-view product browser allows users to see how a selected list of products or product information maps to different but independent perspective of their concerns (views), each of which is represented by a tab. Users can expand or shrink this list of products/product information by entering a search query, and/or selecting or deselecting sub-categories under a view. Sub-categories may be displayed, for example, as a hierarchical tree structure, an image map, a 3D model, etc. Each view provides a unique and independent user perspective of the product content.
[0019] Advantageously, users can start product exploration or configuration from the view they find easiest to understand or move from one view to another as they gain an understanding. A system according to the present invention advantageously offers users the ability to find products or product information accurately and effectively, even though the user only has vague or ill-defined ideas about what he/she would like to buy, does not completely comprehend the product line, or is not familiar with the terminology used by the business. In each view, users may select/deselect various sub-categories, which in turn may increase or decrease the space of selected product content.
[0020] In one aspect of the present invention, a system for accessing information is provided comprising: a server system comprising a product database; a user profile database for storing user profiles; and a domain model for modeling a set of views associated with product information stored in the product database, wherein said product database, the user profile database and the domain model are stored in a storage device; and a client system comprising a multi-view product browser for rendering a set of views stored in the storage device, each view comprising a perspective of product data, said product data being organized under sub-categories under each view, wherein as the user searches through the set of views, the multi-view product browser maps information from each view to other views for refining said information; and a hypertext browser for generating relevant data from said product data based on at least one of a user query, domain knowledge, and the user profile, wherein a degree of relevance is reflected for each view, the sub-categories under each view and the relevant data with respect to the user query.
[0021] In another aspect of the present invention, a method of accessing information comprising the steps of: rendering a set of tabs on a user interface, each tab comprising a perspective of product data, wherein said product data is organized under sub-categories under each tab; generating relevant documents from said product data with respect to a user query, wherein a degree of relevance is reflected for each tab, the sub-categories under each tab, and the relevant documents with respect to the user query; and locating the relevant documents under the set of tabs, wherein as a user searches through the set of tabs, information from each tab is mapped to other tabs for refining the relevant documents.
[0022] In yet another aspect of the present invention, a method of accessing information comprising the steps of rendering a set of tabs on a user interface, each tab representing a perspective of information of a product line, wherein as a user searches through the set of tabs, information from each tab is mapped to other tabs for refining said information; and summarizing actions of each user in a user summary, wherein if the user clicks on a help button provided on the user interface, said user summary is displayed to an agent.
[0023] These and other aspects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 illustrates an exemplary user interface window according to an embodiment of the present invention.
[0025] [0025]FIG. 2 depicts an exemplary user interface window in which a user query is entered according to an embodiment of the present invention.
[0026] [0026]FIG. 3 shows an exemplary user interface window in which a relevant document is mapped into the multi-view product browser according to an aspect of the present invention.
[0027] [0027]FIG. 4 depicts an exemplary user interface window in which the hypertext browser returns a list of relevant product documents with respect to the sub-category “Filling and Dosing” according to an aspect of the present invention.
[0028] [0028]FIG. 5 is an exemplary user interface in which the relevant product documents are mapped into a different view according to an aspect of the present invention.
[0029] FIGS. 6 - 9 are exemplary user interfaces for showing how a list of relevant product information is mapped into various views according to an aspect of the present invention.
[0030] [0030]FIG. 10 depicts an exemplary block diagram depicting a method for updating the relevance of each sub-category and each view.
[0031] [0031]FIG. 11 depicts an exemplary user summary window showing user intention and knowledge level, which is displayed on the screen of a human agent when a user requests for either anonymous help or in-person help.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] It is to be understood that the exemplary system modules and method steps described herein may be implemented in various forms of hardware, software, firmware, special purpose processors, or a combination thereof. Preferably, the present invention is implemented in software as an application program tangibly embodied on one or more program storage devices. The application program may be executed by any machine, device or platform comprising suitable architecture. It is to be further understood that, because some of the constituent system modules and method steps depicted in the accompanying Figures are preferably implemented in software, the actual connections between the system components (or the process steps) may differ depending upon the manner in which the present invention is programmed. Given the teachings herein, one of ordinary skill in the related art will be able to contemplate or practice these and similar implementations or configurations of the present invention.
[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. In other instances, well known process steps have not been described in detail in order not to unnecessarily obscure the present invention.
[0034] [0034]FIG. 1 illustrates an exemplary user interface window 100 according to an embodiment of the present invention. User interface window 100 comprises a hypertext browser 102 (which can be, for example, a hypertext markup language browser) for displaying browsing results to browse product information (catalogs) or an information space such as the World Wide Web. In addition, the hypertext browser can display search results in response to a user query, and/or also take into account the user profile information and domain knowledge.
[0035] A multi-view product browser 104 allows users to see how, for example, a selected list of product information maps to various independent perspectives of their concerns (views) 106 , each of which is represented by a tab or a “hotspot”. Each view 106 provides a unique and independent user perspective of product data (e.g., unique and independent perspectives of each product line or product information). For example, here there are four views: “Systems”, “Instrumentation”, “Solutions”, and “More”. Each of these views includes sub-categories 108 which provide more detailed information about each view. The sub-categories can be displayed, for example, as a hierarchical tree structure, an image map, a 3-D model, etc. For example, if the “Systems” tab is selected, a hierarchical tree structure (as shown here by sub-category 108 ) may be displayed.
[0036] It is to be noted that the views may be rendered based on the user profile, community statistics and/or historical data. Community statistics may comprise, for example, a user's characteristics such that the user can be characterized based on his/her preferences to belong a particular group of people. Historical data may comprise, for example, past actions of the user while on the website.
[0037] The user interface may also include a browsing format selector 116 in which the user may select a browsing format based on, for example, the site's content or the user's profile. Here, the browsing format selector 116 is set on, for example, “content” which presents the user interface 100 in a browsing format based on the web site's content. Alternatively, it is to be appreciated that the user interface 100 may be presented in, for example, a format according to a user profile by setting the browsing format selector to “profile”.
[0038] In a preferred embodiment, the user interface 100 also allows users to discuss their specific needs and/or problems with a human agent by seeking either anonymous help or in-person help. For example, the user interface includes a Request Tip button 110 for requesting anonymous help, in which a human agent is asked to try to find useful/relevant information pertaining to the user's customer actions summary. If the human agent is successful, s/he then directs any relevant web content to be displayed on the user's screen.
[0039] The user interface 100 includes a Discuss button 112 for requesting in-person help in which an online web conference session is invoked between the user and a human agent. Unlike the anonymous mode where a user receives anonymous help (without the need to identify him/herself), the in-person mode offers live/interactive help over the Internet. Both the Request Tip button and the Discuss button offer a seamless transition from a self-help mode to an agent-assisting mode. In both the anonymous help and in-person help cases, a human agent on a business site receives a call from a user, reviews a customer actions summary generated by the server and displayed on the agent's screen, and then tries to assist the user who made the request based on the information shown in the customer summary.
[0040] User interface 100 also includes a query interface 114 where a user may enter a search query to expand or narrow down the amount of product information according to the user's particular interests. A document filter interface 118 may also be provided to filter a list of returned documents (product information) according to, for example, whether they are highly relevant, somewhat relevant, or with respect to a user profile.
[0041] In a preferred embodiment, the tabs of each view 106 can have different color shades according to each view's relevance with respect to, for example, an entered search query.
[0042] Advantageously, users can start product exploration or configuration from the view they find easiest to understand, and can move from one view to another while the information of each view is mapped seamlessly into a next view.
[0043] [0043]FIG. 2 depicts an exemplary user interface window 200 in which a user query is entered according to an embodiment of the present invention. Here, for example, a search query “bottle filling and dosing” is entered in the query interface 114 . Results of the search pertaining to the search query are displayed by the hypertext browser 102 as selected product information 202 . Preferably, the selected product information 202 is separated into, for example, two different categories indicating, for example, “important” 204 or “less important” 206 information. Preferably, the different categories are distinguished in some way, for example, they can be highlighted in two different colors or written in different fonts.
[0044] In addition, a relevance bar indicator 208 is preferably provided to indicate the relevance of each of the sub-categories 108 with respect to the entered search query. The relevance indicator may comprise, for example, a horizontal bar (as illustrated by 208 ) which can be shaded/colored in to show a ratio of relevant product information with respect to all product information indexed under each sub-category. For example, the amount which the bar is shaded in can reflect a ratio of that sub-category's importance with respect to the search query, e.g., a bar with a larger portion of shaded/colored space indicates that the sub-category it represents is more relevant to the search query than a bar with a smaller portion of shaded/colored space.
[0045] [0045]FIG. 3 shows an exemplary user interface window in which a relevant document 301 is mapped into the multi-view product browser 104 according to an aspect of the present invention. Here, for example, the document “Packaging Filling and Dosing” is under the “Solutions” view. The relevance indicators demonstrate an increased relevance of the “Intro: Packaging” and “Filling and Dosing” sub-categories.
[0046] The user may then for example, set the sub-category “Filling and Dosing” as relevant. The system will then automatically add all documents indexed under “Filling and Dosing”, even though they were not initially included in the list of all relevant documents. FIG. 4 depicts an exemplary user interface window in which the hypertext browser 102 returns a list of relevant product documents 401 with respect to the sub-category “Filling and Dosing” according to an aspect of the present invention. Here, there are, for example, ten relevant product documents 401 .
[0047] [0047]FIG. 5 is an exemplary user interface in which the relevant product documents 401 are mapped into a different view 106 according to an aspect of the present invention. For example, here, the relevant documents 401 are mapped onto the “Systems” view 501 , thus narrowing the list 401 to 8 documents 503 which are both relevant to the entered user query “Bottle filling and packaging” and which fall under the “Systems” view 501 .
[0048] The user may then view documents under each sub-category of the mapped view, using, for example, the relevance indicators 208 as a guide for indicating the most relevant sub-categories. For example, in FIG. 5, the PLC sub-category 505 has a relevance indicator which indicates that it contains a particular ratio of relevant documents that fall under the PLC sub-category. The relevant PLC documents will be displayed by the hypertext browser as a result of selecting the PLC sub-category 505 .
[0049] The present invention also offers a custom brochure feature in which a user may indicate which documents he is interested in as he explores the website, and these documents of interest will be “collected” (for example, for a group printout at a later time). Advantageously, since the present invention includes information which links these collected documents to their respective sub-categories, the custom brochure feature can automatically generate a “table of contents” which links to the collected documents being selected by the user. This table of contents (e.g., list of respective sub-categories) organizes the selected documents and allows the user to see how his separate selected documents of interest relate to each other.
[0050] FIGS. 6 - 9 are exemplary user interfaces for showing how a list of relevant product information is mapped into various views according to an aspect of the present invention. FIG. 6 depicts a list of sub-categories 601 appearing under an “Operation” view 603 . Selecting a sub-category 605 results in a relevant list 607 having four documents.
[0051] [0051]FIG. 7 shows a relevant list 701 which results from mapping the relevant list 607 into a “Performance” view 703 . Here, for example, the user selects “High” and “Medium” sub-categories 705 under the “Performance” view, which results in a list of three possible product documents 701 which conform to the user's requests so far (i.e., which fit both under the sub-category 605 and the sub-categories 705 .
[0052] The user can further refine his/her search by selecting another view, for example, in FIG. 8 a “Requirements” view 801 is selected and specific requirements 803 desired by the user are entered. This results in narrowing down the list of relevant documents to just one document 805 . In addition, it is to be appreciated that the user can go back under a previous view to further refine any desired qualities.
[0053] Advantageously, a system and method according to the present invention offers users the ability to select products or product information despite the users lack of knowledge of the details of or answers to questions about which products or product information they are looking for. The present invention enables information to be presented from_multiple perspectives that are each a unique description of the information and are cross-linked to each other.
[0054] [0054]FIG. 9 is an exemplary block diagram illustrating a method for generating search results according to an aspect of the present invention. Any free-text search engine 901 can be used to find a relevant list of products or product information (for example, selected product information 202 ) from a product (catalog) database 903 based on an entered user query 905 .
[0055] A relevance optimizer 907 then classifies the retrieved list into a list 913 of the “important” 204 and the “less important” 206 categories based on a user profile stored in a user profile database 909 , and a domain model 911 . The “important” 204 product information is, for example, information which is of interest to the user (based on the user profile) and which is not isolated in the domain model 911 . The domain model 911 comprises a complete set of multiple views 106 , each of which further includes a hierarchical list of sub-categories. Links from a list of product or product information to a set of sub-categories are created during an authoring process and stored in the product catalog database 903 .
[0056] [0056]FIG. 10 depicts an exemplary block diagram depicting a method for updating the relevance of each sub-category and each view. In a preferred embodiment, the relevance of each view as well as each sub-category is determined using the list 913 and the domain model 911 . Initially, the relevance of each sub-category under each view is determined in step 1001 by computing recursively the ratio of “important” vs. the total of all product information that are indexed under the sub-category. If this ratio is above a pre-determined threshold, the sub-category can be highlighted and the ratio shown using the relevance bar indicator 208 . The relevance of each view can then be shown (step 1003 ) by altering, for example, the color, shade and/or pattern of each tab 106 according to the accumulated relevance ratios of all corresponding sub-categories under each view. Advantageously, these color (and/or shade/pattern)-coded views and highlighted sub-categories give users an idea about which views and sub-categories to look under for relevant information, thus enabling a more efficient search.
[0057] According to one aspect of the present invention, a method is provided for interactively selecting/deselecting a sub-category. The preferred embodiment allows users to select a sub-category (essentially making a sub-category relevant) or to deselect a sub-category (i.e., making a sub-category irrelevant). The former case occurs when users feel a particular sub-category contains products or product information that is very relevant to their needs. In such a case, the preferred embodiment makes all product or product information indexed under this sub-category “important”, and updates the list 913 and the relevance of each view and each sub-category accordingly (e.g., such that if a view or sub-category now contains a higher ratio of important products/product information, the relevance indicators of each view and sub-category are updated to reflect this).
[0058] In addition, if a particular sub-category is not considered relevant by a user, the user may deselect that sub-category. In this case, the preferred embodiment removes all products or product information indexed under this category from the previous list 913 , and updates the selected product information 913 and the relevance of each view and each sub-category accordingly. It is to be appreciated that a sub-category can be set as relevant or not relevant (irrelevant) manually by the user as the user selects or does not select (deselects) various sub-categories. As the user manually selects or deselects a sub-category within one view, the importance of sub-categories within another view may be automatically modified to reflect the change.
[0059] [0059]FIG. 11 depicts an exemplary user summary window 1100 showing user intention and knowledge level, which is displayed on the screen of a human agent when a user requests for either anonymous help 110 or in-person help 112 . A preferred embodiment of the user summary window 1100 includes a text summary 1101 , a URL field 1103 , and a “Go” button 1105 . The text summary 1101 displays, for example, a summary of the user's search requirements (i.e., the user's intentions and knowledge level) to assist the agent in understanding the needs of the user. If the agent finds information pertinent to the needs of the user, the agent can enter, for example, a URL field 1103 and send the URL to the user by pressing the “Go” button 1105 .
[0060] Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the present invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims. intended to be included within the scope of the invention as defined by the appended claims. | A system and method for providing a user interface for product exploration and product configuration in which a seamless integration of browsing, query, and human assistance is provided which is customized to the knowledge level of each individual user. Product information is displayed on a web site under multiple views represented by a tab on the user interface. If the user is not familiar with a web site's layout, s/he can type in a query, and documents based on relevance to the entered query will be returned. Relevance indicators are provided to indicate a relevance of each view, for each sub-category under a view, and a degree of relevance of the returned documents based on the user query. Actions of each user are summarized in a user summary, wherein if the user clicks on a help button provided on the user interface, said user summary is displayed to an agent. | 6 |
BACKGROUND OF THE INVENTION
The invention relates to spectacle frames of the split rim type, usually made of metal materials, with the rim member having a cross sectional indentation to hold the beveled edge of the lens securely. The split allows the opening of the rim when inserting or removing a lens, and endpieces are attached to the ends of the split, by solder or other means, in order to provide a method for locking the split in a closed position.
It is important that the ends of the split be held firmly together so that the lens will be locked securely in place. A lens falling out of a frame is a major inconvenience to the wearer, and frequently results in the expense of a broken lens having to be replaced. Whatever means is used for holding the split closed must not only keep the frame closed tightly, but at the same time allow the frame to be opened for occasions where the replacement of a lens may be necessary.
In the history of related art, screws have been by far the most commonly used method for holding these described endpieces together and keeping the split rim tightly closed around the lens. Unfortunately, it is very common for such screws to gradually work loose, causing a lens in some cases to fall out. Even in cases where the lens may not fall out, it is still possible that the lens can rotate within the frame, thus altering the optical properties of the glasses when prescription lenses are involved. It is particularly critical that the cylinder axis of a lens for the correction of astigmatism is maintained in the proper rotational alignment to be effective. Therefore, even minor loosening of the frame is undesirable.
The threads of the typically tiny screws used, as well as the receptor threads in the eyeglass frame, often cause additional problems by stripping out. Quite frequently a perfectly good frame can be rendered useless only because of stripped threads. A nut and bolt combination can often provide a makeshift solution to this problem, but is generally unattractive and is also subject to loosening.
Many previous attempts have been made to solve the drawbacks of screws for this application, but have been either ineffective or have introduced other disadvantages. The continued predominance of the use of screws in this regard is a strong indication of the failure of previously proposed methods to adequately fulfill all of the requirements of spectacle frames.
Designs using clips which slide or snap either onto the eyewire endpieces (patent #'s 308,344 & 2,006,917) or over the screw to prevent it from backing out ( #1,882,153) have been proposed. Another approach has been the bending of certain parts to prevent loosening of the frame (#735,917) or turning of screws (#2,740,327). The problems introduced by these designs are numerous. In some cases they make insertion of the lenses during assembly of the eyeglasses awkward, which is an important consideration for the many optical laboratories which provide one hour service, where ease and speed of assembly are required. In other previous attempts the option of replacing a lens which may have been accidentally broken is impractical, particularly when parts of the frame must be restraightened and bent again during the lens replacement, leading to problems with metal fatigue. Sometimes the extra parts attached to the frame may be bulky and compromise the visual appeal of the eyewear, which is an important consideration of eyeglass wearers. In other previously designed systems, springs have been used to maintain a closing force on the opening in the eyewire (#'s 3,473,839, 3,609,018, 4,256,387, 4,360,252 & 4,813,775). None of these approaches solve the problems of screws without introducing others. In many cases, the frames are designed so that they can only be partly opened for lens insertion or removal. This can lead to problems and even hazards when trying to insert or remove glass lenses which can chip under these circumstances, thus causing lens spoilage. Some of the designs are not suitable for frames made of thin metal materials, therefore having limited application to only certain other types of frames. In other cases, the design does not allow any tolerance for lenses having anything but an absolutely precise fit for the frame. If the lenses are even the slightest amount too large, the device will not allow closure of the frame. Other methods, such as toggle levers or cam type arrangements have also been proposed ((#'s 2,730,012, 2,73,709 & 2,754,724) but are generally too bulky in appearance to be suitable for delicate frames made of thin materials. Soldering the frame closed has even been proposed (#2,104,503), but this is clearly impractical because of the adverse effects the high temperatures would have on plastic lens materials, as well as difficulties with lens replacement. Still another approach has been the design of frames where the screws are mounted transversely to the plane of the lens (#'s 1,590,719 & 3,762,804). These designs still use conventional screws, however, and in addition sometimes make assembly of the glasses more difficult because the frame must be held in a tightly closed position while the screw is being inserted. Those skilled in the art will readily admit the difficulty of holding a frame closed and keeping the lens positioned properly while simultaneously trying to engage the threads of a tiny screw into the frame.
SUMMARY OF THE INVENTION
The principle object of the invention is to provide an improved method for securely holding closed eyeglass frames of the split rim type, without loosening over time.
Another object is to allow easy replacement of lenses without the need for any tools not already at the disposal of optical technicians.
Still another object is to provide a device where slightly oversized lenses can still be mounted in the eyeglass frame.
These and other objects will become evident as the specifications for various advantageous embodiments of the device and their operation are explained in detail.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows part of a spectacle frame having a rim design as seen from the side of the frame which would face the wearer.
FIG. 2 is a detailed elevated perspective drawing of the rim split in a slightly open position, with the first and second endpieces attached to the rim at the ends of the split.
FIG. 3 is a perspective drawing of the connecting device used to hold the endpieces together.
FIG. 4 shows the opposite face of the lower endpiece as was seen in FIG. 2.
FIGS. 5 & 6 show the outside face of the second endpiece illustrating two possible embodiments.
FIG. 7 shows part of a spectacle frame with a different temple attachment design than the frame in FIG. 1.
FIGS. 8 & 9 show cross sections along the line 8-9 in FIG. 7 of two additional embodiments.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 partially shows a spectacle frame in which the lenses are held by a split rim (1), with two endpieces (2 & 3) secured to the ends of the split by solder or other means, which are used to hold the split in the normally tightly closed position.
FIG. 2 shows, in detail, the two endpieces of the split rim (1) when the split is in the open position. Positioned in the outside face of the first endpiece (2a) is a cylindrically shaped bore or chamber (4) which extends only partially through the endpiece. Centered on the same axis is a smaller diameter bore (5) which extends through the remainder of the endpiece and out the other side. A flat shelf (6) is positioned at the bottom of the larger bore or chamber, the plane of the shelf being perpendicular to the axis of the cylinder bores. Slot shaped openings (7) extend radially outward from the center of the smaller bore as far as the perimeter of the large diameter bore.
The inside face of the second endpiece (3b) can be seen below and in close proximity to the first endpiece. The second endpiece also contains a cylindrical bore (8) of the same diameter as the small diameter bore (5) in the first endpiece, as well as slot shaped openings (9) extending radially outward from the bore, of substantially the same dimensions and oriented in the same direction as the analogous openings (7) in the first endpiece. FIG. 3 shows a connecting device, where a compression type spring (10) surrounds a cylindrical shaft (11), which at one end has a screw type slotted head (12) and at the other a pair of perpendicularly aligned lugs (13). The shaft of the connecting device is of a diameter just large enough to allow a snug fit in the smaller diameter bores located in the endpieces but not so large as to prevent free rotation within the bores. The diameter of the connecting device head and spring is slightly smaller than the larger bore in the first endpiece, so that the bore can act as a chamber to house the spring and the screw head can be recessed therein.
FIG. 4 shows the outside face (3a) of the second endpiece, with the small diameter bore (8) and slot shaped openings (9) as described above, and in addition, two depressions (14) in the otherwise smooth surface of the outside face, oriented at 90 degrees to the slot shaped openings and of the same length and width as the same openings.
When the inside faces of the endpieces are placed together to close the split, it can be seen that the slot shaped openings (7 & 9) will be in perfect alignment with each other. The connecting device can be then be inserted, lugged end first, into the chamber opening on the outside face of the first endpiece, and through the use of a suitable screw driver, can be pushed so that the lugs will be urged into and all the way through the aligned slot shaped openings of the second endpiece. At this time, the spring (10) of the connecting device will occupy the space in the chamber formed by the large diameter bore (4) and will be compressed between the shelf (6) and the connecting device head (12).
The dimensions of the endpieces and connecting device are such that when the insertion has reached the point where the spring is fully compressed, the lugs will have passed completely through the second endpiece and slightly beyond the outside face thereof. Upon rotation of the screw driver engaged in the head, the connecting device can be rotated until the lugs are aligned with the depressions on the outside face of the second endpiece, and upon release of pressure from the screw driver the connecting device will then hold endpieces together firmly by the tension of the spring between the shelf in the chamber of the first endpiece and the head of the connecting device. The engagement of the lugs in the depressions will keep the connecting device in a locked position due to the tension of the spring, unlike an ordinary screw which could rotate and back out over time.
A second embodiment, not illustrated, is also possible, in which the connecting device in FIG. 3 contains only one lug instead of two. Consequently, only one of the two slot shaped openings are necessary in the endpieces as shown in FIGS. 2 and 4 for such an embodiment.
FIG. 5 shows the outside face of the second endpiece (3) attached to the end of the eyewire (1) for a third embodiment, which also utilizes a connecting device with only one lug and endpieces with only one slot, as described in the second embodiment. In this third embodiment, the surface of the second endpiece over which the lug would rotate (17) is not flat, but would gradually slope upwards from the slot (9) to the depression (14). The part of this surface next to the slot would be somewhat recessed into the face of the endpiece, and the amount of recess would decrease in the direction of the depression (14) until it is become raised to the point where it is substantially flush with the rest of the endpiece face just as it reached the depression (14). Thus, as the connecting device is rotated the effect of this sloping surface will be to gradually increase the tension on the spring and pull the frame closed tightly, until the lug reaches the depression (14) and is locked therein. This will aid in closing the frame by gradually increasing the force as the screw head of the connecting device is rotated.
The same principle is used in a fourth embodiment, of which the outside face of the second endpiece is illustrated in FIG. 6. The outside face of the second endpiece for this embodiment differs from the one in from the previously described embodiment in that there are two sections of recessed sloping surface (17 & 18) divided by a first depression (14) between the two sloping sections and the second depression (19) at the far end of the second sloping surface.
When the connecting device is first inserted, the lug will protrude through the slot (9) as in previously described embodiments. Upon rotation of the connecting device the lug will slide up the recessed sloping surface (17) until it reaches the first depression (14). In situations where the lenses have been edged slightly too large for the frame, this first locked position of the connecting device may provide adequate tension on the spring to hold the frame closed securely. If the lenses are the exact size of the frame, the connecting device can then be rotated further in the same direction, causing the lug to slide further upward along the second sloping surface (18) to a second locked position in the depression (19) at the end. This embodiment would therefore be able to cope with lenses which were made slightly too large for the frame, which is not an uncommon situation encountered by opticians or technicians while assembling eyeglasses.
In FIG. 6, there are two locked positions as defined by the two depressions (14 & 19) which are located 120 degrees apart, but the same or a greater number of positions at different combinations of angles would be possible.
FIG. 7 shows the eyewire (1) and the outside face of the first endpiece (2a) of a frame utilizing a different method of temple attachment than in FIG. 1. In this type of frame the end of the temple (15) is located between recessed portions of the two endpieces, rather than being connected by means of a separate bracket as for the frame illustrated in FIG. 1. In a fifth embodiment employing the type of temple attachment illustrated in FIG. 7, two connecting devices are used, of which the heads (12) can be seen; the one towards the lower left holds the eyewire tightly together, while the one towards the upper right acts as a pivot on which the temple end rotates.
A cross section of this fifth embodiment along the line 8-9 in FIG. 7 is shown in FIG. 8. Attached to the rim (1) are the endpieces (2 & 3), which are tightly together in the closed position. The connecting device springs, in a compressed state, can be seen located within the chambers formed by the large bores (4) in the first endpiece beneath the heads (12) of the connecting devices. The connecting device is the two lugged type, and the lugs (13) can be seen engaged in the depressions in the outside surface of the second endpiece (3). In this case the connecting device on the left provides tension for holding the eyewire tightly closed, while the connecting device on the right serves to hold the temple end (15) firmly between the endpieces while at the same time acting as a pivot for reciprocating movement of the temple.
FIG. 9 shows an additional embodiment, similar to the one in FIG. 8 but in this case the temple end (15) is held by a screw (16), the head of which is flush with the top of the temple end. This allows the split in the frame to be opened without having to remove the temple, which would make reassembly of the glasses less awkward when lens replacement was required. When the frame is in closed position, the temple retaining screw will be held tightly beneath the first endpiece, thereby preventing possible loosening of the temple attachment. Thus, this embodiment will address the problems of the loosening of both eyewire and temple attachment screws.
While only a few embodiments of the present invention have been shown and described, it is apparent that numerous alterations, omissions and additions may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims. | This disclosure refers to the securing of lenses in an ophthalmic mounting having a split rim eyewire using a spring loaded connecting device. | 6 |
This application is a national phase of, and claims priority from, PCT Application No. PCT/IL2008/000885, filed on Jun. 29, 2008, which claims priority from U.S. Provisional Application No. 60/958,297, filed on Jul. 5, 2007, all of which are hereby incorporated by reference as if fully set forth herein.
FIELD OF THE INVENTION
The present invention relates to an apparatus, device and a method for harvesting a blood vessel, and in particular, to such an apparatus, device and method employing an ultrasonic blade.
BACKGROUND OF THE INVENTION
Heart disease is known as the leading cause of death in the United States. The National Center for Health Statistics reported over 2.4 million deaths in the US in the year 2001, with heart disease being the leading cause with 700,142 cases. This accounts for 38.5% of all deaths in the United States in that year. According to the National Institutes of Health, heart disease is also the leading chronic preventable disease in the US today, outpacing all other preventable conditions. In statistical terms, the number of US cases affected by heart disease is 64,400,000, or 22.6% of the US population, with an associated cost of the disease for 2004 exceeding $368.4 billion.
Heart disease is defined as any disorder that affects the heart's ability to function properly, and is most commonly caused by narrowing or blockage of the coronary arteries, which supply blood to the heart itself. The treatment for coronary artery disease is mainly by angioplasty and surgical revascularization, known as coronary artery bypass graft (CABG). Due to the nature of the disease, CABG has become one of the most commonly performed procedures in the world. According to the American Heart Association's Heart Disease and Stroke statistics, 467,000 CABG surgeries comprising 346,000 men and 121,000 women were performed in the United States in 2003. This number increased to about 600,000 cases in 2005.
During a CABG surgery, vessels are connected to the heart to bypass the coronary artery blockages. Of those vessels, or conduits, the internal mammary artery (IMA) is the primary and the most preferred by surgeons for the bypass procedure. The IMA is harvested from the chest wall near the sternum and attached to the heart to supply blood to the area supplied by the blocked vessel experiencing hypo-perfusion.
The IMA (also known as the internal thoracic artery or ITA) is a major conduit for use in coronary artery bypass graft. The IMA is located on the interior surface of the chest on each side starting from the neck down, originating at the subclavian artery and ending at the superior epigastric artery. The IMA supplies blood to the chest wall including the ribs, sternum and breasts.
The mammary artery is an important conduit for bypass surgery as it is an artery rather than a vein; accordingly it has the lowest risk of thrombosis and occlusion among all other conduits. Consequently the state of the mammary artery has important prognostic value, and a well harvested and good flowing mammary artery determines the successful outcome of the surgery.
One of the reasons the IMA is a preferred conduit for CABG is due to its special properties and characteristics that differentiates it from other vessels. For example, in the inner layer of the IMA, the endothelium is thicker in this artery compared to other arteries; therefore, this vessel is rich in endothelial cells. Endothelial cells are responsible for the arterial features of a vessel, being active in production of multiple substances that actively mediate the arterial wall activity and maintenance of the vessels integrity. Due to these specific properties, the mammary artery has the best outcome as a graft in CABG. These outcomes are translated as the patency rate of 90% in 10 years when a mammary artery is used as a graft compared to 50% patency rate of a vein graft. Therefore, when planning a CABG, a mammary artery graft is always preferred and is almost always attached to the most important coronary artery, the left anterior descending artery (LAD).
The first stage of CABG is the preparation of the conduits for bypass. This stage includes harvesting the mammary artery (IMA) from the chest wall and harvesting veins from the leg. Surgeons primarily use the conventional method where the chest cavity is opened.
During conventional CABG the surgeon opens the chest by sawing the sternum at the midline. The pleura covering the artery and the lungs is then opened or retracted laterally exposing the IMA. This procedure provides the surgeon with a direct visual of the IMA, while half of the chest is pulled back and elevated with a retractor. Once the IMA is exposed, the surgeon uses electrocautery to divide the artery with its accompanying veins and some tissue as a pedicle or as a single vessel (skeletonized). The IMA side branches are usually divided following the application of a metal clip close to their origin on the artery and cauterization on the chest side. When the artery is divided superiorly up to its origin and inferiorly down to its bifurcation, it is cut at its lower end and at this time its tip is prepared and ready to be attached to the coronary artery that is being bypassed
This traditional technique can be used to harvest each of the mammary arteries, left and/or right. The conventional harvesting procedure takes 15 to 40 minutes. Complications associated with the conventional technique include injury to the vessel itself or to the chest wall. Vessel injuries include bleeding during or following the harvest, direct injury to the artery or thermal injury with decreased flow, while the thermal injury to the chest wall causes sternal wound hypoperfusion with and infection. Any such complications might impede vessel flow and leave it unusable as a conduit for bypass. Furthermore, opening the chest cavity itself is detrimental to the patient, both increasing the risk of the operation and also increasing the recovery time required.
Although minimally invasive techniques are available for harvesting the artery, such as the endoscopic technique which is used as part of the totally endoscopic coronary artery bypass (TECAB) surgery, these techniques have many drawbacks. For example and without limitation, the procedure requires extensive training, it is very time consuming and it requires expensive and specialized equipment. In this method robotic arms are used to harvest the IMA through small incisions on the side of the chest wherein visualization is facilitated by video means. Harvesting using the robotic technique lasts for 60 to 70 minutes. When compared to the conventional technique and despite the cosmetic advantageous, the risk of injury using the robotic technique is higher. The increased risk is primarily due to the limited field of view and limited range of motion of the robotic arms provided by this method. Furthermore, there is also a higher risk of bleeding during the harvest that may require further medical intervention, such as chest opening to control the bleeding.
A well harvested artery obtained with minimal damage to the chest wall has significant effects on postoperative course. As being a major blood supplying artery to the chest wall, there is some compromise of the chest wall blood supply after harvesting the artery and diverting the flow to the heart instead of the chest wall. The combination of this relative hypo-perfusion with surgical intervention serves as a risk for surgical wound infection, a complication that results in high morbidity and mortality rates. This risk is significantly higher in patients with diabetes (40% of CABG patients), who already suffer a microcirculation damage associated with diabetes.
SUMMARY OF THE INVENTION
There is an unmet need for, and it would be highly useful to have, an apparatus, device and method for harvesting a blood vessel by using an ultrasonic blade which will be capable to work also in a minimally invasive 25 approach, for example for harvesting of the internal mammary artery in preparation for CABG procedure.
The present invention overcomes these drawbacks of the background by providing an apparatus, device and method suitable for dissecting a blood vessel using either minimally invasive or conventional techniques. By 30 “dissecting” it is meant cutting, coagulating or harvesting the blood vessel or tissue thereof.
In some embodiments, there is provided an apparatus, device and method for harvesting the internal mammary artery (IMA) in a minimally invasive endoscopic procedure or alternatively in an open chest procedure.
A preferred embodiment of the present invention relates primarily to a system for performing IMA harvesting from the chest wall as a conduit for coronary artery bypass graft surgery. Preferably, the apparatus, device and method may be applicable for both open chest and minimally invasive techniques. The preferred embodiment of the present invention provides a heart surgeon with a fast and reliable tool that preferably shortens the harvesting time, therefore reducing the risk of injury. For example, the harvesting time experienced during a conventional open chest surgical procedure takes from 15 to 40 minutes, while using the robot assisted minimally invasive harvesting techniques requires 60 to 70 minutes; however, the device according to a preferred embodiment of the present invention is expected to reduce the IMA harvesting time, without limitation to optionally up to about 15 minutes, more preferably up to about 10 minutes and most preferably up to about 5 minutes.
Preferably, the present invention provides an apparatus, device and method for harvesting the mammary artery (IMA) either through conventional procedure having a fully open chest, or using minimally invasive surgery techniques through a small incision, in a fast and reliable fashion.
According to a preferred embodiment of the present invention the harvester is introduced to the chest cavity and placed in the appropriate harvesting site thereafter beginning to progressing along the mammary artery. Most preferably, the device according to the present invention dissects and divides the IMA preferably using a camera providing a real time depiction of the harvesting procedure (although optionally through direct visual contact by the surgeon, for example during open chest surgery).
Preferably and optionally, harvesting the IMA is facilitated with the use of an ultrasonic scalpel. Most preferably, the ultrasonic scalpel according to the present invention provides increased precision, minimal charring, minimal lateral thermal tissue damage, improved hemostasis and consequently lower risk of bleeding.
Preferably, an ultrasonic scalpel achieves coagulation and tissue dissection at lower temperatures than standard diathermy. Preferably, the potential advantages of ultrasonic scalpel includes less lateral tissue damage, minimal smoke and no electrical energy passed to or through the patient. Optionally, other forms of scalpel may be used, for example including but not limited to an optical scalpel, comprising lasers which may be integrated with the device of the present invention. Preferably the lasers are low power lasers, in place of the ultrasonic scalpel.
Preferably, the ultrasonic scalpel functions to convert electrical energy into mechanical energy resulting in longitudinal oscillation of the blade at about 45 KHz to about 500 KHz. Preferably, the ultrasonic scalpel achieves coagulation and tissue dissection at lower temperatures than standard diathermy.
Without wishing to be limited in any way, the device according to the present invention provides improved patient safety as no electric current is passed through the patient. Accordingly, the risks associated with the direct use of electric current are avoided. Preferably, the device according to the present invention prevents thermal injury to the IMA during the harvesting process. Thermal injury may also lead to increased risk of spasm, flow compromisation and malperfusion of the target coronary vessels following bypass.
Preferably, the apparatus, device and method of the present invention provides a short harvesting time which further minimizes the chest wall injury and reduces the extent to which the blood supply is compromised, therein lowering the risk of wound infection particularly important in high risk patient groups that may also suffer from one or more other diseases, for example including but not limited to diabetes, peripheral vascular disease, obesity and the like.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples provided herein are illustrative only and not intended to be limiting. Implementation of the method and system of the present invention involves performing or completing certain selected tasks or steps manually, automatically, or a combination thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in order to provide what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
FIG. 1 is a perspective view of a schematic diagram of the IMA harvester according of an exemplary device according to the present invention;
FIG. 2 is a side view of a schematic diagram of the arm of the IMA harvester according of an exemplary device according to the present invention;
FIG. 3 is a close up perspective view of a schematic diagram of the 30 arm of the IMA harvester according of an exemplary device according to the present invention;
FIG. 4 is a top down view of a schematic diagram of the arm of the IMA harvester according of an exemplary device according to the present invention;
FIG. 5 is a close up frontal view of a schematic diagram of the arm of the IMA harvester according of an exemplary device according to the present invention;
FIG. 6 is a close up planar view of a schematic diagram of the control box of the IMA harvester according of an exemplary device according to the present invention;
FIG. 7 is a close up perspective view of a schematic diagram of the control box of the IMA harvester according of an exemplary device according to the present invention;
FIG. 8 is an exemplary method for harvesting an artery according to the present invention;
FIG. 9 is a perspective view of the device according to a preferred embodiment of the present invention while harvesting the IMA within the chest cavity.
FIG. 10 is a close up view of FIG. 9 depicting the dissector of the present invention while harvesting the IMA;
FIG. 11 is a back view of FIG. 10 ;
FIG. 12 is a frontal view of FIG. 10 ;
FIG. 13 is a perspective view of FIG. 10 taken from the harvester's camera according to an optional embodiment of the present invention;
FIG. 14 shows another exemplary, illustrative, non-limiting 25 embodiment of the harvester;
FIG. 15 is a schematic block diagram of an exemplary, illustrative, non-limiting embodiment of a system according to the present invention; and
FIG. 16 shows an external view of a portion of the system of FIG. 15 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is of an apparatus, device and method for dissecting a blood vessel, for example for efficient harvesting of the IMA artery in preparation for CABG. The principles and operation of the present 5 invention may be better understood with reference to the drawings and the accompanying description.
A preferred embodiment of the present invention provides for a device for efficient harvesting of the internal mammary artery (IMA) in preparation for CABG. Preferably, the device of the present invention 10 comprises a dissector head, a controllable arm and a control unit. Optionally, auxiliary devices may be coupled to the device of the present invention. Preferably, the auxiliary devices act as accessories to the device of the present invention. For example, auxiliary devices may optionally include but is not limited to a computer, display, processor, memory, 15 auxiliary power source, optical energy source, RF power source, communication port, ultrasound power source, ultrasound generator, ultrasound transducer (preferably a piezoelectric transducer) or the like.
Preferably, the dissector head is fluidly connected to the controllable arm that is then stably connected to the control unit. Preferably, the 20 connection between the dissector head and the controllable arm is mediated by at least one or more connectors preferably providing full range of motion of the dissector head relative to the controllable arm. Optionally, a plurality of connectors may be used to provide a full range of motion, preferably providing 180 degree range of motions between the controllable arm and 25 dissector head. For example, the connector mediating the fluid connection between the dissector head and the arm may optionally include but is not limited to any type of joint such as a ball and socket joint, a rotating hinge, a hinge, pneumatic actuators or the like as is known in the art.
Optionally, at least one or more connectors may be controlled 30 automatically, manually, or semi-automatically. For example, manual control may be facilitated by a user's control of the range of motion optionally utilizing a grip lock to set a given range of motion or lock on a particular position. Similarly, automatic and semi-automatic control may be facilitated by the use of at least one or more motors to control the relative position of the dissector to the arm, preferably in a full 360 degree range of motion.
The arm is preferably stably fixed to the control unit. Optionally, the range of motion of the connection between the arm and dissector is controlled by the control unit. Most preferably, the control unit comprises manual, semi-automatic and automatic means for controlling the range of motion of the dissector head relative to the arm.
Preferably, the dissector head according to the present invention is adapted for dissecting a blood vessel, for example for dissecting and harvesting the IMA from the chest wall. Optionally and preferably the dissector head comprises two parallel jaws connected on either side of the controllable arm, therein preferably forming a right and a left jaw, respectively. Preferably the right and left jaw are separated by up to about 5 cm. Most preferably the jaw separation distance is controllable ranging from about 2 mm to up to about 5 cm, although depending upon the location and size of the camera, the minimum jaw separation distance is preferably at least about 1 cm.
Furthermore, the size of the pedicle preferably ranges from about 5 mm to about 5 cm, more preferably from about 1 cm to about 4 cm.
Preferably, each jaw set comprises two extending arms protruding from a base that preferably perpendicular relative to the horizontal plane of the controllable arm. Optionally, each protruding arm is about 2 cm to 5 cm long, most preferably each protruding arm is between 2 cm to 4 cm long and most preferably it is about 3 cm long. Optionally the base is up to 5 cm in length, optionally it is between about 3 cm and 5 cm, preferably the base is at least 3 cm in length, and most preferably it is 4 cm long.
Preferably, the horizontal distance between the left and right jaws is controllable and mediated by a controllable connector. Preferably the right and left jaw are separated by up to about 5 cm. Optionally, the jaw separation distance is controllable ranging from about 2 mm to up to about 5 cm, although as noted above, depending upon the size and location of the camera, the minimum distance is preferably at least about 1 cm. Most preferably, the controllable jaw separation distance is between about 1.5 cm to up to about 3.5 cm from the internal side of the right and the left jaws. Preferably, the controllable connector provides at least one or more, and preferably all, of vertically oriented pivoting, vertical and horizontal positioning control of the right and left jaws. For example, the controllable connector may be a motorized connector having control means at the control unit for example including but not limited to a joystick, dial, peddle or button. Optionally, the controllable connector may form a bridge to horizontally connect the right and left jaws.
Preferably, each jaw set comprises two extending jaw arms protruding from a base that is preferably perpendicular relative to the horizontal plane of the controllable arm. Optionally a first jaw arm is fluidly connected to the vertical base, preferably forming an obtuse angle optionally about 90 degrees to about 120 degrees relative to the base. Optionally, the base and the first extension (jaw arm) form a single member, optionally referred to as the superior jaw. The superior jaw is optionally and preferably fixed. Optionally, a second jaw arm forms an inferior jaw that is preferably fluidly connected to the jaw base. Optionally, the second jaw arm is pivotally connected to the base with a pivot preferably providing the inferior jaw arm controllable motion relative to the jaw base. Optionally and preferably, the inferior jaw movement causes an object to be dissected with a dissecting modality, preferably an ultrasonic scalpel, such as for example including but not limited to the pedicle, or the like tissue, to be squeezed between the fixed superior jaw arm and the movable (preferably pivotable) inferior jaw arm. Preferably, the inferior jaw member movement is pivoted relative to the base provides the dissector head with the ability to control the jaw opening between the inferior and superior jaw members. Optionally, the jaw arm movement provides a scissor like motion.
Optionally both superior and inferior jaw arms may be individually pivotally joined at the common base. Optionally, the superior jaw may be pivoted at the upper portion of the base while the inferior jaw may be pivoted at the lower portion of the base. Also optionally, each jaw arm is attached to the base by an offset; if pivotal motion is provided, preferably pivoting occurs at the offset. Alternatively, pivoting may occur between the jaw arm and the offset.
Preferably the parallel jaws are used to manipulate and dissect the IMA from the surrounding tissue by forming scissor like movements along the length of the harvested artery, most preferably the IMA. Preferably, dissection and harvesting of the IMA is provided by an ultrasonic scalpel blade that preferably extends at least partially along the inferior edge of the superior jaw. Optionally, the ultrasonic scalpel blade edge extends alternatively on the superior edge of the inferior jaw or jaws.
Also optionally the superior edge of the inferior jaw features an ultrasonic blade; however preferably the superior edge of the inferior jaw features a fixed blade. The two positions may also optionally switched, in which the superior jaw features the fixed blade and the inferior jaw features the ultrasonic scalpel blade. Each such ultrasonic scalpel blade preferably features a transducer although optionally two such blades may share a transducer.
Optionally, the jaw arms (superior and inferior) are closed before the ultrasonic scalpel blade is activated; also optionally such activation may be manual or automatic.
Preferably and optionally, the interior face of at least one jaw arm comprising an ultrasonic blade providing an ultrasonic scalpel edge along the interior face edge of the jaw arm. Most preferably, the interior face of the jaw arm which features the ultrasonic scalpel comprises the ultrasonic transducer providing one or more ultrasonic scalpel edges.
Optionally, the jaws may be further provided with an extension of the ultrasonic blade extending to the distal end of at least one jaw arm. Preferably such an extension is provided for the superior jaw arm.
Preferably, the ultrasound transducer producing the ultrasonic energy in the scalpel edges may be fixed in the arm or control unit. Preferably, the ultrasonic scalpel utilized is as known and accepted in the art. Preferably, the ultrasound transducer produces a frequency of about 45 KHz to about 500 KHz.
Most preferably, an ultrasonic scalpel is provided on each of the right and left jaws and on each of the respective jaw arms. A preferred embodiment of the present invention comprises a dissection head with a plurality of ultrasonic scalpel surfaces; most preferably, four scalpel surfaces are featured on the interior face of each of the jaw arms.
Preferably, the distance between the right and left jaws is controllable and most preferably the distance may be defined based on the anatomy of the harvested IMA. Optionally, the distance between the right and left jaws is automatically adjusted but is preferably manually adjusted, optionally and preferably according to the IMA anatomy. This adjustment is preferably performed upon entry on the chest at the beginning of the harvest procedure and is more preferably only performed once. Optionally and preferably, the distance between the right and left jaws is manually adjusted, preferably by a surgeon, according to IMA anatomy. Most preferably the distance between the right and left jaws is controllably adjusted upon entry into the chest wall.
Preferably, the dissector head movement is controllable throughout the IMA harvest. Most preferably, the dissector head movement is controllable allowing it to progress along the length of the IMA and in keeping with the IMA anatomy, chest curvature, or the changes in angles. Optionally, the dissector head movement is automatically determined. Optionally, the dissector head movements are manually controlled.
Most preferably, the jaws are manually activated by an operator handle, preferably disposed in the control unit. Preferably the operator handle is operated by the surgeon and is a manual procedure. Most preferably, the manual manipulation of the operator handle are translated to the motion of the right and left jaw. Most preferably, such manual manipulation activates the jaws and the ultrasound transducers to generate an ultrasonic scalpel edge along the interior edge of each of the jaw arms while providing them with scissors like motion along the IMA path. Preferably, the operator handle provides the dissector head with sufficient degrees of freedom providing motion resembling that of a wrist.
Preferably, the dissector head comprises a bridge that connects the right and left jaws providing a means for fixing the jaws relative to one another and relative to the controllable arm. Optionally, the bridge may comprise a camera, light source, horizontal hinge, vertical hinge, pusher (described in greater detail below), and a controllable connector.
Optionally, the bridge may form a means for connecting the controllable arm to the dissection head as discussed above. Preferably, the bridge provides both vertical and horizontal motion providing a user with controllable range of motion.
A preferred embodiment of the present invention comprises a pusher that is preferably disposed between the right and left jaw of the dissector head. Most preferably, the pusher is disposed adjacent to the right jaw. The pusher provides a means to manipulate the IMA directly, while keeping the arterial tension during IMA harvesting. The pusher comprises a telescopic rod, an ultrasonic scalpel blade and a motor. Most preferably, the distal end of the pusher is provided with an ultrasonic scalpel to manipulate arterial branches of the IMA as the dissector advances along the length of the IMA.
As its name suggests, the pusher pushes the artery downward, thereby maintaining tension and also straightening the artery for ease of cutting and harvesting. In addition, the pusher may be used to push away redundant tissue. The redundant tissue might be confusing and may be misleading for the surgeon without maintaining the artery under tension in a straightened position. Also if a camera is present, the pusher may be used to maintain the line of sight of the camera.
Preferably the pusher motor is utilized to control both the telescopic and vertical movements of the telescopic rod. Optionally and preferably, the movement and range of motion of the pusher are controllable by controlling the pusher motor. Preferably, the control means is provided by the control unit and may for example include but is not limited to joystick, dial, button, switch or the like means to control at least one or more preferably a plurality the pusher's range of motions. Optionally, the pusher motor is an electrical actuator motor, activated by switch or joystick on the control handle.
Optionally the telescopic rod is extensible up to about 3 to 4 cm forming an ultrasonic scalpel edge of about 12 mm.
A preferred embodiment of the dissector head according to the present invention comprises at least one camera optionally disposed on the dissection head bridge. Most preferably, the dissector head comprises a camera providing an operator with a visual depiction of the harvesting process as it is taking place. A camera preferably provides a visual depiction of the IMA anatomy allowing the operator to properly manipulate the dissector within the chest cavity, while monitoring the dissector's movements along the IMA path. Preferably, the camera utilized is a digital pin hole camera that may be disposed with the body and most preferably sufficiently small to allow use within the chest cavity. Optionally, the camera is a state of the art camera such as that utilized in endoscopic procedures or the same as used in the digital webcams or camcorders.
Most preferably, the camera comprises a light source providing the operator with sufficient field of view. The light source is preferably a state of the art light sources as is known and accepted in the art, for example including but not limited to a LED (light-emitting diode), fiber optic or the like. Optionally, the light source may be integrated with the camera. Optionally, the light source may be independent of the camera.
Most preferably, the camera's field of vision may be visualized on an auxiliary display screen. Optionally, the camera may be connected to the display screen by wired or wireless means as is known and accepted in the art. For example, the camera may be linked to an external display screen 5 using a USB (Universal Serial Bus) connection through an appropriate port disposed on the control unit.
An optional embodiment of the present invention provides for a plurality of cameras disposed within the dissector head. Optionally, at least one or more cameras may be disposed on the inferior or superior jaw arms; however, as at least the tips (or latter portions) of the jaw arms are to be inserted into the tissue, the camera placement should be such that the functionality of the arms and also of the camera(s) is not significantly reduced or altered. Optionally, at least one or more camera may be disposed along the pusher.
An optional embodiment of the present invention provides for at least one camera that may be interchangeably placed between various location within the dissector head, for example including but not limited to right jaw, left jaw, pusher, base, bridge, jaw arm, inferior jaw arm or the like.
A preferred embodiment of the present invention provides for a control unit that preferably provides control for the different facets and mechanisms of the dissector head. Most preferably, the control unit comprises a plurality of control switches and buttons to control the movement of the pusher motor and jaws, providing power to the ultrasonic scalpel, provides means to connect to the camera to an external display.
The control unit preferably comprises a power switch, joystick, manual operator handle, locking handle and a plurality of auxiliary ports.
Preferably, the joystick is utilized to control the activity of the pusher motor providing both telescopic and vertical movement to the pusher as well as controlling the ultrasonic scalpel preferably disposed therein.
Preferably, the manual operator handle provides an operator means to manually maneuver the jaws along the length of the IMA.
Preferably, the locking handle provides an operator means to set the position of the dissection head once it has been set.
Preferably a mains power switch provides power to the system particularly for the automatic manipulation of the jaws, ultrasonic scalpel.
Optionally and preferably the control unit comprises a plurality of auxiliary ports for example including but not limited to communication ports, power ports, USB (universal serial bus), wireless USB, wireless communication port, ultrasonic scalpel port, optical, IR (infrared), RF (radio frequency), fiberoptic, video, audio or the like peripheral port. Optionally, one or more ports provide the operator with the ability to couple additional tools to the device of the present invention.
Optionally, the device and apparatus according to the present invention is made in whole or in part from medical grade metals and/or plastics for example including but not limited to aluminum, titanium, stainless steel, nitinol or the like materials, composites or alloys thereof as is known and accepted in the art. The jaws are also preferably made of the above materials; the blades of the ultrasonic scalpel are preferably made of a metal, composite, alloy or other combination of metals; however, they may optionally be covered in plastic. Preferably, the materials used are sterile, and are optionally sterilizable (for example through autoclaving or another procedure) as is known and accepted in the art. Optionally, the embodiments of the present invention may be composed in whole or in part of single use or multi use materials.
Referring now to the drawings, please note that the same figure labels are used throughout the specification to refer to the same or similarly functioning components.
FIG. 1A shows an IMA harvesting device 100 according to the present invention comprising dissection head 110 , arm 102 and control unit 140 . Although harvesting device 100 is described as a device for harvesting 30 IMA, it should be noted that in fact it may optionally be used for many different types of tissue dissection and operations. Preferably, dissection head 110 is used within the chest cavity to harvest an IMA (not shown) wherein arm 102 is used to help navigate and direct dissection head 110 through the chest cavity while transferring control instructions, for example including but not limited to movement and positioning instruction and power source from control unit 140 .
FIG. 1B depicts an apparatus 101 comprising IMA harvesting device 100 of FIG. 1A further comprising auxiliary devices through a plurality of auxiliary ports. For example, display 170 is preferably used to display the video captured through an optional camera (not shown) preferably mounted within dissection head 110 . Ultrasound power source 160 is optionally and preferably attached through a different auxiliary port.
FIG. 2 depicts a close up side view of dissection head 110 in greater detail. Dissection head 110 is controllably coupled to arm 102 through a moveable joint 104 . Joint 104 may optionally be realized in the from of a ball and socket, moveable hinge, motor or the like that are optionally automatically controlled with a motor or more preferably manually controlled by an operator using control unit 140 (not shown).
Dissection head 110 comprises a pair of superior jaws 114 and inferior jaws 112 that are joined through a jaw base 113 . Optionally, superior jaw 114 is fixedly joined with jaw base 113 while inferior jaw 112 is connected to jaw base 113 with pivot 120 . Pivot 120 preferably provides inferior jaw 120 with rotation about the pivot axis allowing a user to control the opening formed between the superior jaw 114 and the inferior jaw 112 . Pivot 120 therefore provides the movement of the inferior jaw 112 relative to base 113 and superior jaw 114 producing the scissor motion utilized for harvesting and dissecting the IMA (not shown).
One or both of superior jaw 114 and inferior jaw 112 optionally comprises an ultrasonic scalpel; in the embodiment shown, both superior jaw 114 and inferior jaw 112 feature such a scalpel for the purpose of illustration only and without any intention of being limiting. The inferior jaw 112 comprises ultrasonic scalpel 122 along its interior face edge. Similarly, superior jaw 114 comprises ultrasonic scalpel 124 along its interior face edge. Preferably, a plurality of ultrasonic face edges are utilized to dissect the tissue in harvesting the IMA; however, alternatively each of inferior jaw 112 and superior jaw 114 features only one ultrasonic blade edge (not shown). Also optionally, only inferior jaw 112 or superior jaw 114 is present, but features a plurality of ultrasonic blade edges (not shown). Also optionally, each such ultrasonic blade is exposed or is only partially covered by a “housing” (not shown), for example for greater ease of attaching and detaching the blades.
Optionally and preferably, at least one jaw of inferior jaw 112 or superior jaw 114 has at least two degrees of freedom with respect to jaw base 113 and/or arm 102 . More preferably, one jaw (most preferably the jaw featuring an ultrasonic scalpel 122 or 124 ) has at least two degrees of freedom. Most preferably, the jaw only has two degrees of freedom.
Also optionally and preferably, each pair of jaws 112 and 114 has at least two degrees of freedom with respect to the arm 102 .
Dissection head 110 further comprises pusher 116 , preferably providing the dissected IMA with tension, thereby allowing the jaws 112 and 114 to continuously harvest without undue burden. Preferably, pusher 116 is telescopic and is moveable in the vertical axis. Preferably, the movements, both telescopic and vertical, provided by pusher 116 are mediated by pusher motor 128 . Preferably, pusher motor 128 is controlled by control unit 140 (not shown). Optionally, the pusher motor 128 is an electrical actuator motor, activated by switch or joystick on the control handle (not shown).
Preferably, pusher motor 128 is disposed on bridge jaw 108 that joins jaw base 113 . Jaw base 113 is further provided with a horizontal adjustment 118 preferably allowing jaw base 113 to move horizontally about bridge 108 .
FIG. 3 depicts a close up perspective view of dissector head 110 according to a preferred embodiment of the present invention. The 30 perspective view reveals camera 130 and light source 132 that are optionally disposed on bridge 108 and between the right pair of jaws 115 and the left pair of jaws 117 . Preferably, camera 130 is a pin hole digital camera comprising a light source 132 . Camera 130 provides an operator with visualization of the harvesting procedure preferably in near real time, optionally and preferably content depicted by camera 130 may preferably be broadcast to an external display 170 , as depicted in FIG. 1B . Optionally, no camera 130 is present and/or is detachably removable.
FIG. 3 further provides a closer depiction of pusher 116 that comprises an ultrasonic scalpel 126 . Preferably ultrasonic scalpel is utilized to harvest an IMA (not shown).
Bridge 108 preferably mediates and connects left pair of jaws 117 and right pair of jaws 115 . Bridge 108 further comprises horizontal adjustment 119 providing horizontal adjustment to control the distance between left pair of jaws 117 and right pair of jaws 115 .
FIG. 4 is a top down view of the IMA harvester according of an exemplary embodiment according to the present invention wherein pusher 116 is more clearly depicted. Pusher ultrasonic scalpel 126 is preferably utilized to facilitate the harvesting of an IMA without damaging the harvested artery. Optionally, a further ultrasonic scalpel 127 and 129 may be disposed in an optional embodiment of the present invention at the distal edge of the inferior jaws 112 and superior jaws 114 , providing a further means to dissect the artery.
Optionally and preferably, one or more (and more preferably all) of the components of dissector head 110 (according to any embodiment herein) are replaceable and/or disposable, most preferably including without limitation camera 130 , the ultrasonic transducers (not shown), the pusher 116 , inferior jaws 112 and superior jaws 114 , and the blades of ultrasonic scalpels 126 , 127 and 129 .
FIG. 5 provides a close up frontal view of the harvester 100 according to an exemplary embodiment of the present invention.
FIGS. 6 and 7 provide close up planar view of control unit 140 of the harvester 100 according to an optional embodiment of the present invention.
A preferred embodiment of the present invention provides for a control unit 140 that preferably provides control for the different facets and mechanisms of the dissector head 110 . Most preferably, the control unit 140 comprises a plurality of control switches and buttons to control the movement of the pusher motor and jaws, providing power to the ultrasonic scalpel, and optionally providing means to connect to the camera to an external display (if such a camera is present).
Control unit 140 comprises a controller 142 , a power switch 154 , pusher joystick 146 for controlling the movements of the pusher (not shown), manual operator handle 144 , locking handle 148 (for locking the dissector unit or head (not shown)) and a plurality of auxiliary ports.
Preferably, pusher joystick 146 is utilized to control the activity of the pusher motor 128 (not shown) providing both telescopic and vertical movement to the pusher 116 as well as controlling the ultrasonic scalpel 126 (not shown) preferably disposed therein.
Preferably, the manual operator handle 144 provides an operator means to manually maneuver the jaws along the length of the IMA.
Preferably, the locking handle 148 provides an operator means to set the position of the dissection head once it has been determined.
Preferably a mains power switch 154 provides power to the system particularly for the automatic manipulation of the jaws, ultrasonic scalpel.
A plurality of auxiliary ports is optionally available through controller 142 as depicted in FIG. 1B . The present close up view depicts optional auxiliary ports for example including but not limited to mains power supply 156 , a USB camera port 158 and the ultrasonic scalpel port 154 .
FIG. 8 depicts an exemplary method according to the present invention wherein the IMA is harvested in preparation for a CABG procedure. In stage 802 the chest is opened sufficiently to permit entry of the harvester device according to the present invention; optionally the chest may be opened through either thoracotomy or sternotomy or other means known and accepted in the art, or alternatively a small incision may be made for minimally invasive surgery. In stage 804 the harvester according to the present invention is introduced into the chest cavity. In stage 806 the artery is located optionally and preferably utilizing the camera disposed within the dissector head according to an optional embodiment of the present invention. However, if a minimally invasive technique is not being used, then the camera may optionally be omitted. In stage 808 the two jaws are positioned on each side of the artery, preferably at a location along the artery where the artery is most visible. Optionally and preferably during stage 808 the locking handle is placed and locked into place, most preferably until the artery's anatomy depicts need for realignment or handle locking, for example during stage 812 below for fine tuning. In stage 810 the distance between the right and left jaws are adjusted, preferably in accordance with the anatomy of the IMA being harvested. In stage 812 the tips of the jaws then inserted into the fascia on each side, possibly activating the ultrasonic scalpel to facilitate the entry and the jaws are activated slowly until slight development of the pedicle.
In stage 814 the jaws are incorporated with the ultrasonic scalpel edges on each side of the artery, and the camera (if present) is focused and pointed on the midline on the inferior surface of the artery.
In stage 816 , full activation of the jaws is instituted, while the jaws are kept symmetrically on each side of the artery using the camera view and/or through visual control from the surgeon, for example for open chest surgery. In stage 818 the fascia is continuously divided and the flap develops further, the pusher is activated by the joystick in the control unit to keep the pedicle in tension downward making the jaws activities more efficient and separating the artery from the chest wall. In stage 820 the harvesting procedure continues with the aid of the pusher, jaws and optionally camera, while the operator looks for instances where IMA might have branches coming off on the IMA's posterior surface and penetrates to the chest wall, then this branch will be cauterized using an ultrasonic scalpel at the edge of the pusher which is controlled by the joystick in the handle.
The dissector is advanced proximally to the either side of the mammary artery while the motion of the jaws is continuing to complete the harvest. The active parts of the jaws with ultrasonic scalpel are located on the internal side of the jaws. Approximation and scissor movement of the jaws cuts and divides the mammary artery with its fascia on each side, while the branches on each side are cauterized with the ultrasonic scalpel.
In stage 822 the exact direction and location of the dissector is monitored either through direct visual contact by the surgeon, or optionally with the camera which is placed in between the jaws (for example for minimally invasive surgery). If the present, the camera is focused on the artery in the center of the field maintains the two jaws in parallel to the path of the mammary artery, and also maintains symmetrical pedicle dissection on each side.
In stage 824 as the harvest continues the device according to the present invention is adjusted to anatomy specific to the harvested IMA. For example, as the dissector proceeds, the curvature of the chest or the angles change and the dissector head will be adjusted accordingly during the progress.
In stage 826 the artery is disconnected from its distal end and preferably prepared for grafting by being divided at the distal end. The artery stays connected at its proximal end, while the distal end of the artery is then preferably attached to the heart.
FIGS. 9 to 13 provide a visual depiction of the use of device according to the present invention as described in FIG. 8 . FIG. 9 is a depiction of the insertion of the IMA dissector 100 through the chest wall and placed adjacent to the IMA about to be dissected, effectively as described in Stages 802 to 808 . IMA 200 is shown within the chest cavity 202 as dissector unit 110 (or head) is moved into position for dissection.
FIG. 10 provides a close up view of FIG. 9 wherein dissector head 110 is activated to harvest IMA 200 within the chest cavity 202 using ultrasonic scalpel 124 on superior jaws 114 that surround IMA 200 .
FIG. 11 provides a back view of FIG. 10 wherein IMA 200 is clearly visualized and is being harvested with the use of pusher 116 and pusher ultrasonic scalpel 126 , while maintaining jaws 114 and 112 aligned around IMA 200 , as depicted in Stages 816 to 822 .
FIG. 12 provides a frontal view of FIG. 10 wherein camera 130 and pusher 116 are readily visualized in monitoring IMA 200 as depicted in Stage 822 of FIG. 8 .
FIG. 13 provides a physician view as depicted by camera 113 , optionally and preferably visualizing IMA 200 on an auxiliary external monitor 170 of FIG. 1B (not shown).
FIG. 14 shows another embodiment of the device of FIG. 1 , shown as a harvesting device 1400 featuring a dissector controller 1402 in the form of a joystick as shown. This joystick is actually a second joystick for harvesting device 1400 and preferably separately controls the motion of the dissector head 110 .
FIG. 15 is a schematic block diagram of an exemplary, illustrative, non-limiting embodiment of a system according to the present invention. As shown, a system 1500 features a dissector unit 1502 , which may optionally and preferably be implemented according to any of the embodiments of the dissector head as described herein. Dissector unit 1502 is controllably connected to an adjustable connecting arm 1504 and is preferably controlled by the user through a harvester hand piece 1506 . Optionally and more preferably, further control is provided by a foot pedal 1508 or other separate control for controlling functionality of ultrasonic generator 1510 .
Dissector unit 1502 preferably features one or more ultrasonic transducers 1512 , for which power is provided by ultrasonic generator 1510 . Each ultrasonic transducer 1512 preferably provides ultrasonic power to one or more ultrasonic scalpel blades 1514 . Such an implementation, in which ultrasonic transducer 1512 is located very close to ultrasonic scalpel blade(s) 1514 , is preferred for minimally invasive surgery, as it permits a small, compact dissector unit 1502 to provide power at the location needed. An ultrasonic shock absorber 1520 is also preferably provided in order to absorb any energy from ultrasonic blades 1514 .
Dissector unit 1502 also optionally and preferably features a mechanical control unit 1540 for providing mechanical control of the jaws (not shown).
A camera 1516 preferably provides images or other visual information to a display 1518 , which may optionally be a computer monitor, television screen or video screen, or any other type of display.
Harvester hand piece 1506 also preferably includes a mechanical control unit 1522 , which preferably also controls movements of dissector unit 1502 , more preferably including movements of the jaws (not shown) featuring ultrasonic scalpel blade(s) 1514 . Harvester hand piece 1506 also preferably includes an electronic control unit 1524 , for providing electronic control to dissector unit 1502 (for example for controlling the motor for the pusher (not shown), controlling functionality of ultrasonic scalpel blade(s) 1514 and so forth).
FIG. 16 shows an external view of a portion of the system of FIG. 15 . As shown, a dissector unit 1600 (which may for example optionally be implemented as shown in FIG. 15 ) preferably features an ultrasound unit 1602 , for containing the ultrasonic transducer(s) and any electronics required thereof. Ultrasound unit 1602 is connected for transmitting ultrasonic energy to at least one ultrasonic scalpel blade 1614 . Optionally, a gripping arm 1608 holds the tissue with sufficient tension for the operation of ultrasonic scalpel blade 1614 .
A mechanical unit 1604 preferably includes all of the mechanical controls, for example for controlling the movements of upper jaw 1610 and lower jaw 1612 .
Ultrasound unit 1602 is also preferably connected to an arm 1606 , as is also shown in the other embodiments provided herein and as previously described.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. | The present invention relates to an apparatus, device and a method for harvesting blood vessels, and in particular, to such an apparatus, device and method in which the internal mammary artery (IMA) is harvested for coronary artery bypass graft (CABG) surgery using a minimally invasive approach or a conventional procedure. | 0 |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to powder coating technology which can be used to produce hard, uniform coatings through the heat curing of a powder uniformly applied to a surface. In particular, it relates to the production of a coating composition and to its application to a surface which coating composition, after heating, forms a shiny, reflective metallic appearance. The preferred powder coating is based on aluminum flakes and a thermosetting resin.
Bright, shiny, metallic finishes are desirable in many commercial applications. The major source of these shiny finishes is chemical or electrical plating of metals such as chrome. However, chemical coating processes such as chrome treatments have environmental and economic drawbacks. Chromium is a major source of heavy metal contamination and is expensive to produce. With this in mind, a great deal of attention has been given to producing shiny coatings with powder compositions. Powder coatings are generally produced by mixing a binder with other constituents which can be melt mixed, cooled, and pulverized to provide a powder material that is easily applied to a conductive surface. The powder or surface is then heated to cause the powder coating composition to melt and flow to form a continuous coating.
The powder coating compositions are most commonly applied through electrostatic spray coating or fluidized bed coating. In the electrostatic spray process, the coating composition is dispersed in an air stream before being subjected to a high voltage field in which the particles pick up an electrostatic charge. The charged particles are then attracted to a grounded or charged substrate. The coated substrate is then heated to a temperature sufficient to melt the powder coating and to cause it to flow providing a smooth, even finish.
Fluidized bed coating makes it possible to apply films as thick as about 2.5 mm. In this method, the powder coating composition is fluidized in a fluidized bed by passing a fluidizing gas stream into a vessel containing the powder coating. A substrate is heated in an oven to a temperature above the melting point of the powder coating and is then dipped into the fluidized bed. The powder coating particles contact the hot surface, then melt and flow on the substrate surface. See generally, Kirk-Othmer, Concise Encyclopedia of Chemical Technology, pp. 944-945 (1985).
One attempt to achieve a chrome-like finish has been through the incorporation of aluminum particles or aluminum flake into powder coating compositions. However, mere incorporation of aluminum flake into powder coating compositions has not produced a highly shiny, reflective chrome-like appearance as measured by the high reflectance of conventional chrome electroplating without special and additional processing techniques and additives.
Powder coating composition and processes for the production of such powder compositions are needed which can form a glossy, highly reflective metallic finish that appears to be as shiny as chrome plate.
U.S. Pat. No. 5,045,114 describes a powder product that results from a process of preparing a powder coating material which can be applied to a substrate to form a coated article having a glossy, high reflective, metallic finish. The process comprises milling a resinous binder and about 1 to 12 parts of aluminum particles per 100 parts of binder, whereby the resinous binder and aluminum particles are milled and then separated from both milling media and oversized particle to produce a powder coating composition having a particle size between about 5 to 250 microns. Such powder coating materials, when applied and melt formed on a substrate surface, can exhibit high gloss, high reflectance and a metallic finish. The powder coating compositions can comprise (a) a resinous binder, (b) about 1 to about 12 parts of leafing aluminum particles per 100 parts of binder, and (c) an effective amount of a fluidizing agent per 100 parts of binder which are modified in accordance with the invention. The resinous binder and the aluminum particles are milled and then separated from the milling media and oversized particles to produce a powder coating material having a particle size between about 5.0 and about 250 microns. The aluminum flakes in all examples are provided as a paste of aluminum flakes in mineral spirits.
U. K. Patent No. 1,404,556 titled Particulate Coating Compositions and Coated Articles Prepared Therefrom describes a dry particulate composition comprising a fusible epoxy or acrylic resin and flake particles (selected from titanium nitride flake, nickel sulfide flake, cobalt sulfide flake and manganese sulfide flake, with the flakes embedded in the resin particles or affixed to their surface. Combination with aluminum flake, copper, bronze, brass, chromium and nickel flakes are also shown. The flakes and resin powder are mixed under shear conditions to reduce the size of the flake and to affix the flake to the resin. Pebble mills and any other type of high shear mixer is suggested. Examples show ball milling of the flake and resin particles (Example 1) and melting of the resin and particles in a roll mill (Example 2). A gloss over ninety is asserted to be the result of the process, with Example 2 showing a 20° gloss of 100.
U.S. Pat. No. 5,187,220 describes a thermosetting resin based coating powder containing metal flakes. The powder and flake are mixed at a temperature in the range above the softening temperature of the thermosetting resin, but below the melting temperature of the thermosetting resin, while the powder and flake composition is subjected to mechanical shear forces sufficient to prevent agglomeration of the coating powder particulates.
SUMMARY OF THE INVENTION
A method of manufacturing powder coating compositions, the powder coating compositions, and cured coatings made from the coating compositions are described. The method of preparing the coating compositions comprises combining a preformulated thermally softenable resin powder (having a defined T g ) and highly reflective particles, such as a non-leafing or leafing metallic flake, mica, optically variable pigments and the like (and mixtures of these pigments, particles and flakes), and then mixing the powder and flake under high shear conditions and assuring that the average temperature of the mixture remains below the T g of the resin during the high speed mixing process. The temperature may be maintained below the T g of the resin by repeatedly stopping (or slowing) the mixing (which would have low production efficiency, but would still produce an improved product) or by cooling the mixing equipment where the mixture is present. The process produces compositions which are more stable than compositions previously made by ball milling using aluminum flakes `pasted` in solvent or plasticizer, e.g., mineral spirit, and provides coatings with a high degree of reflectivity. The process of the present invention can be used with pasted or non-pasted flakes and may display an improved performance, at least over some ball milled non-pasted powder coating systems. The process may be summarized as a process for the manufacture of a powder coating material comprising the steps of:
providing as a mixing mass of both particulate resin binder having a T g and reflective particles within a container,
mixing the mixing mass under high speed mixing conditions which are capable of elevating the temperature of the mixing mass above the T g of the resin, and
controlling heat in the mixing mass during mixing to keep the temperature of the mixing mass below the T g of the resin during mixing (at least to a degree so that agglomeration of the resin particles is prevented).
The process of the present invention deagglomerates the reflective particles from each other and associates the reflective particles with the resin particles, yet allows the process to be performed for extended periods of time to increase the gloss (reflectivity) of the coated product. The flakes or particles do not necessarily fuse (e.g., by melt-stick adhesion) to the resin particles, but may only distribute themselves over the surface of the particles with surface tension, electrostatic or other physical attachment means. Fusion of the reflective particles to the polymer or resin particles (as with bonded powder coatings) may be subsequently effected or may occur to some degree with impact bonding, but is not essential to the practice of the present invention. The term association includes both this superficial physical attraction and attachment or contact and also includes actual melt stick adherence or impact fusion of the reflective particles to the resin particles. There is an eventual point of diminishing return in the blending process. Additional reflectivity can not be achieved or reflectivity begins to decrease because of excessive breakdown of the reflective pigments. However, this point is only gradually reached and can be readily determined by routine experimentation.
A powder coating composition made by this process may comprise, for example, thermally softenable resin particles having a number average diameter of between about 5 to 500 or 5 to 250 microns, preferably between about 15 to 60 microns, reflective particles, pigments and/or flakes (preferably leafing metallic flakes) having a number average maximum diameter of between about 4 and 45 microns, and preferably having less than 2% or less than 1% by weight of resin of any liquid petroleum products. There is an expectation that the powder can be prepared having less than 5% by number of its reflective pigments, particles and/or flakes (e.g., leafing metallic flakes) agglomerated with other flakes which agglomeration would reduce gloss. The composition may be alternatively described as a powder coating composition comprising thermally softenable resin particles having a number average diameter of between about 15 and 60 microns, reflective pigments, particles and/or flakes (e.g., non-leafing or leafing metallic flakes) having a number average maximum diameter of between about 4 and 45 microns, and having less than about 1% or less than 2% by weight of resin of any liquid petroleum products, the powder when coated onto a surface in a continuous manner (e.g., at a thickness of at least about 5 microns or at least about 10 microns) and melted and cured, providing a reflectivity of at least 400 at 20 degrees viewing angle.
The powder coating composition may be used in a process for providing a reflective surface on a substrate comprising applying the powder coating composition onto the surface, melting the resin in the powder coating composition, and hardening said resin to form a coating having a reflectivity at 20 degrees viewing angle of greater than about 400.
DETAILED DESCRIPTION OF THE INVENTION
The invention concerns a powder coating composition which comprises (a) a resinous binder, (b) about 0.5 to 12 parts of reflective particles (for example reflective metal, preferably shiny metal, and most preferably shiny aluminum particles, mica, optically variable pigments, and the like) per 100 parts of binder, and (c) optionally an effective amount of a fluidizing agent per 100 parts of binder, whereby the resinous binder and reflective particles are blended at high shear mixing rates to produce a powder coating composition having a particle size between about 5 to about 60 microns (numerical average particle diameter for all particles).
The terminology referred to herein as "high shear" or "high speed" mixing can be related to many different factors within the process, and is not merely a function of tip speed and/or revolutions per minute, even though it is convenient and accurate to refer to those values in describing the high speed shearing and speed of the blades within the blender/mixer. The high speed procedure actually can be further described with respect to the energy/time (work) which is being put into the mixture by blending and shearing forces (as opposed to, for example, direct heat energy). In selecting a blender and conditions of operation, there are at least three issues which should be considered in the manufacture of product. The blades (usually measured by tip speed) should achieve a sufficient speed to deagglomerate the flakes (e.g., the aluminum flakes). This value appears to be at least about 2,500-3,000 feet per minute, preferably at least above 3,000 feet per minute at the tip. Two other considerations in the process are related to the energy input from the blender. These two other considerations are the rate of energy applied to the blender (which can be expressed as horsepower per pound of product). As this value is increased, the time in the blender needed to achieve the higher gloss values of the present invention decreases. Additionally, a minimum amount of work must be applied to the product to achieve the high gloss levels. As the total amount of energy applied to the material over a fixed rate of time is increased (without raising the materials temperature over the glass transition temperature or melt temperature of the polymer), the amount of agglomeration is reduced and the gloss increases.
With three separate blenders, the Welex™ (model no. TGAHK8), Mixaco™ (Model no. CM 3-12), and Bepex™ (Turbulizer TC-8), mentioned above, the rate of energy applied to the powder blend was calculated based upon the amount of material in the blender and the power draw of the motor. The power was adjusted, based on the no load power required for the blenders. The power value used in the calculation is the approximate actual amount of energy applied to the powder.
The batch blenders (Welex and Mixaco blenders) operate on substantially the same principles. Each blender has two blades. The bottom or pumping blade creates a vortex of powder. The powder flows up the walls of the container. The top of the mixing vessel has a deflector or is cone shaped. This feature forces the powder that has traveled up the wall of the vessel to fall back to the center of the vortex. The overall mixing pattern is a recirculation of powder in the container. The second blade or dispersion blade is mounted above the pumping blade and is close to the diameter of the mixing vessel (e.g., within 0.6 to 2 cm). This is where the dispersion of the reflective particles occurs. There tend to be three benefits to this flow pattern. The powder is continually recirculated to create a well-mixed powder. The pumping blade forces the powder through the high shear zone. The vortex flow of powder on the wall of the mixing vessel maximizes the heat transfer to the jacket.
The Bepex blender uses some of the same principles, but operates in a continuous manner. The blades in the blender are within 0.6 to 2 cm of the vessel walls. The rotation of the blades or paddles in the container creates a layer of powder on the wall of the container. This maximizes the heat transfer from the powder to the jacket. The paddles can be adjusted to retain or forwardly direct the powder through the blender. By setting the paddles in a configuration which will retain the powder, the residence time for the mixture can be increased and more work performed on the powder. Paddles prior to the retaining blades create the high shear forces in a shear zone for dispersion of the flakes in the resin. All of the systems used required a minimum tip speed for the dispersion blade of at least about 3000 feet per minute. This speed creates the necessary shear stress in the mixing zone required to disperse the reflective particles.
______________________________________BLENDER TYPE RANGE, Horsepower/pound______________________________________WELEX ™ 0.05-0.12 MIXACO ™ 0.25-0.50 BEPEX ™ 0.15-1.0______________________________________
The energy rate per pound of product was calculated based upon the power required for the blender, the blend time, and the amount of material in the batch (or through put) in the blender. As this number is increased under controlled temperature conditions, the gloss of the product increases (asymptotically to a finite limit, of course).
The resinous binder may be either a thermoplastic resin or a thermosetting resin. Generally, the binder is a material which will flow smoothly at elevated temperatures and which will then cure (thermoset) or solidify (thermoplastic) to a final, smooth, even, solid form. Cure may be initiated by the heating or by irradiation applied after or during coating of the powder.
The terms T g , softening point and melting point are often used within the field of polymer chemistry and should be understood in considering the practice of the present invention. The term T g represents the glass transition temperature for the polymer. Usually when the term T g is used without any further description, it refers to the first order glass transition temperature. As polymers may comprise units of different properties (either randomly or precisely positioned within the polymer chain, as in graft or block copolymers), different segments may exhibit different glass transition temperatures. There might be a second order glass transition temperature or a third order glass transition temperature. At each order of the glass transition temperature, there is a relaxation of internal constraints on the polymer and it becomes more plastic (e.g., flowable by shear forces), softer or more pliable. The polymer has not reached a truly fluid state upon attaining T g , and so it is not considered to have melted. The term softening point (especially where differentiated from melting point) is usually a temperature significantly different from to the first order T g . Although not all manufacturers make separate references to the softening temperature and the T g , where references are made, the softening point tend to be significantly higher than the T g . For example, in the materials catalogue and product data sheets of EMS (e.g., for Grilesta V 76-14 Powder Coating Resin), the softening point of the resin is more than 20° C. higher than the T g of the resin. Other resins display such differences with at least 10 or more 0° C. difference between the softening point and the T g . This difference is readily understood as the T g is determined by attainment of a specific viscosity which is not particularly flowable or soft, while the softening point measures an actually observed softening of the resin, thereby requiring a higher temperature.
Representative, non-exclusive, thermoplastic resins include vinyl homo- and copolymers, such as polyethylene, polypropylene, ethylene copolymers, e.g., polyethylene-C 3-8 olefin copolymers, polyvinyl chloride, metallocene based copolymers, polyvinylidene fluoride, ethylene-vinyl acetate, aromatic vinyls, e.g., polystyrene and styreneacrylonitrile resins; polyacrylics, such as polyacrylates and polymethacrylates, e.g., polymethylmethacrylate and polyethylmethacrylate; cellulosics, such as cellulose ethers and cellulose esters; polyesters, such as polynaphthalene terephthalate, poly(alkylene terephthalate), e.g., polyethylene terephthalate; polysiloxanes, polyurethane resins, and polyamides, such as nylon.
The thermosetting resins used in the present invention may be either addition reaction cure or condensation reaction cure thermosetting resins. Representative, non-exclusive, thermosetting resins include epoxies such as diglycidyl ethers of bisphenol A and epoxy cresol/novalacs; phenolic resins, such as novolacs and resols; polyurethanes, such as polyester resins with blocked isocyanate groups; saturated polyesters such as saturated terephthalic acid based polyesters and carboxylated polyesters; and acrylics based on crosslinkable acrylate resins such as carboxyl terminated resins, polysiloxanes and other silicon resins, selfcrosslinking etherified methoxylated resins based on acrylamides and/or methacrylamides. Polyester resins, such as those derived from isophthalic anhydride/glycol and trimellitic anhydride/glycol are also examples of useful materials. Some of these thermosetting resins may not display a traditional T g because they are crosslinked and are more crystalline in nature, showing a sharp melting or softening point. In the practice of the invention with such sharp melting point materials (e.g., where the T g or softening point of the polymer approaches or equals the melting point), the temperature must be maintained below the softening or melting temperature, preferably at least 5 or at least 10° C. below the softening or melting temperature. Most of these thermosetting resins require the use of a curative to achieve a final crosslinked structure, but some of these, e.g., selfcrosslinking etherified methoxylated resins based on acrylamides and/or methacrylamides, will selfcrosslink when subjected to elevated temperatures. Photoinitiation salts and compositions may also be provided to enable cure only upon irradiation. Such photoinitiators, for example, may include free radical initiators and the like. Examples of chemical classes of these photoinitiators include, but are not limited to arylonium salts (e.g., diaryl iodonium, triaryl sulfonium, phosphonium, diazonium), triazine, biimidazoles, benzophenones, benzoin ethers, and the like. The coupling of thermosetting resins and curative agents is well known to those skilled in the coatings art, and any such coupling can be used in the present invention which does not detrimentally affect the metallic finish of the present coating. For purposes of calculating proportions of components in thermosetting systems, curatives are included in the term "binder". Diluents and inert fillers such as coating aids, flow control agents, other binders (e.g., thermoplastic binder mixed with the thermoset resins), dyes, pigments, antistatic agents,, UV absorbers, UV stabilizers, antioxidants, catalysts, anionic or cationic initiators, acid releasing compounds, base releasing compounds, and the like may be present within the resin composition or the powder composition.
In the final, solid form, the resinous binder has a uniform content of reflective particles, such as metallic, e.g., bronze, gold, copper, brass, titanium, silver, or aluminum or metal-coated particles/metal coated films which are preferably introduced as leafing or non-leafing aluminum flakes. Leafing flakes such as leafing aluminum particles or flakes are coated with a material, e.g., stearic acid, and when applied to a surface, the particles can orient in an interleaved structure parallel to the surface of the finished coating. This can result in a highly lustrous and reflective coating. Aluminum flakes are preferably introduced at less than about 50 microns in diameter. The diameter, or more properly the maximum diameter of the metallic particles may have to be determined statistically as they tend to be high aspect ratio particles or flakes, with two major dimensions (width and length) and one minor dimension (thickness) which may be multiples or orders of magnitude smaller than the two major dimensions. When the dimension or diameter of the aluminum flakes are discussed, the maximum average diameter (e.g., either the maximum of width and length or the average of width and length, are referred to. The average width and length may be determined by statistical measurement of the surface area of the flakes, assuming the surface area to be provided by a circle, and "averaging" the width and length by determining what diameter would have provided that area to the flake.) More preferably, the aluminum flakes have a number average particle size of about 1 to about 45 microns, more preferably between 4 and 45 microns, and still more preferably between 5 and 40 microns. Most preferably, the aluminum flakes are sized such that 99.9% pass through 325 mesh screen, i.e., a diameter of less than about 45 microns, most preferably between 8 and 20 or between 10 and 17 microns.
Preferably, the leafing aluminum flakes are introduced as a dry flake rather than the paste of aluminum and solvents having at least about 40 wt-% aluminum flake and more preferably about 60 to 70 wt-% aluminum flake described in U.S. Pat. No. 5,045,114. Preferably, the metal such as the aluminum is introduced in a quantity to provide about 1 to 15 parts of aluminum particles per 100 parts of polymer, binder or resin. This percentage may be considered with or without consideration of the leafing agent (e.g., the stearic acid) used on the flakes.
The use of solvents or viscous liquid carrying agents solvent should be avoided for a number of reasons. These types of agents promote agglomeration and instability in the powder compositions, and may detrimentally affect the other components of the powder coating composition. These undesirable solvents include petroleum-based solvents such as mineral spirits, petroleum spirits, petroleum benzin, petroleum ether, ligroin, refined solvent naptha or mixtures thereof.
In addition to the above, other constituents may be incorporated into the coating composition. Such constituents include flow control agents, scavengers, fluidizers, UV stabilizers, anti-oxidants and fillers. Flow control agents are known in the polymer art and are generally incorporated into the powdered coating composition to improve the flow of the resin as it is melted to provide a smoother finish of the final solid coating. The fluidizer generally comprises inert particulates including inorganic oxide particles such as silica, alumina, zirconia or titania spheres. Fluidizer, if used, would be present as less than 5% by weight of the polymer, preferably less than 2% by weight of the polymer (binder), and more preferably less than 1% by weight of the polymer.
The process of the present invention may be described as follows. Mix a powder resin having a T g , e.g., with particle sizes less than about 500 microns, preferably less than about 250 microns, more preferably less than about 100 microns and most preferably less than about 60 (e.g., 10 to 60 microns) or less than 50 microns, such as between about 10 and 50 microns, between about 20 and 50 microns or between about 30 and 50 microns) with leafing metallic flakes, then blending the resin and flakes as a mixing mass at high shearing, without allowing the average temperature of the mixing mass to rise above the T g of the resin. The prevention of the temperature of the mixing mass from rising above the T g of the resin has been found to provide beneficial effects and avoid harmful effects during the mixing operation. Such beneficial effects include dispersion of the reflective particles and increased reflectivity (gloss) in the cured film. Harmful effects would include melting of the resin, sticking of the resin and agglomeration of the reflective particles and resin. One commercial process blends the resin powder and leafing aluminum flake at high shear speeds, allowing the mixing mass temperature to exceed the T g of the resin. The high speed blending is terminated when significant agglomeration of the resin and flakes has begun. This cessation is to be differentiated from other processes called bonded powder where, after the coating powder has been formed (by the conventional process with some agglomeration), the powder composition is heated briefly (as by additional blending) or allowed to remain at the elevated temperature within the blending process to bond resin to the aluminum flakes to assertedly reduce separation of the flake and binder and avoid disuniformity within the composition. It has been found in the practice of the present invention that sustaining high shear mixing above the T g will cause significant agglomeration and (where thermal curative are present) could even cause some premature cure of the resin, while entirely stopping the high speed shearing when T g is initially reached fails to deagglomerate all of the metal flakes. The failure to deagglomerate the flakes causes loss of reflective power and the possibility of irregularities in the coating because of the clumped particles.
In the present invention, by maintaining an average temperature for the mixing mass which is below the T g of the resin, the high speed shearing may be continued longer, there is less agglomeration, and the powder produces higher gloss as compared to compositions which use the same flakes and resins, and allow the mixing mass temperature to exceed the T g of the resin. The temperature of the mixing mass may be maintained below the T g of the resin by stopping the high speed shear mixing intermittently to allow the temperature to decrease (or even removing the mixing mass entirely from the mixing bowl to a cooling environment), reducing the speed of mixing intermittently to moderate the temperature, or most preferably to provide cooling mechanisms to the mixing mass container or environment so that the temperature of the mixing mass during high speed shear blending is maintained at a low temperature, that is a temperature below the T g of the resin. There are a number of physical effects and phenomena which exist in the resin and the mixing procedure which lead to preferences during this temperature control. Local heating may occur during the high speed shear mixing, especially around the shaft or fins, so local temperatures may exceed the T g of the resin even though the average mixing mass temperature may be at or below the T g of the resin. For this reason, it is desirable to maintain the average mixing mass temperature at a temperature significantly below the T g of the resin. For example, it is preferred that the average temperature of the mixing mass be maintained at a temperature at least about 1° C. below the T g of the resin, more preferably that the average temperature of the mixing mass be maintained at a temperature at least about 2° C. or at least about 3° C. below the T g of the resin, and most preferably that the average temperature of the mixing mass be maintained at a temperature at least about 5° C. or at least about 6-10° C. below the T g of the resin. The effects of potential localized heating around the shaft may be minimized by providing a cooling mechanism to the shaft. With localized temperature control such as this, the average mixing mass temperature may be allowed to approach the T g of the resin more closely.
The cooling can be done by air cooling, liquid cooling, electrical or electronic cooling (e.g., Peltier devices), or any other mechanism which can remove heat from the mixing mass during the high speed shear mixing procedure. Even chemical coolant reactions could be theoretically used, although it would be desirable to have as few extraneous materials present in the resulting composition. As noted above, the use of petroleum products such as the mineral spirits adversely affects properties of the powder composition. Thus, powder compositions with less than about 5% by weight of liquid, distillate or viscous petroleum products are preferred, preferably less than about 2% or less than about 1% or less than about 0.5% by weight of the resin, more preferably less than about 0.1% or less than about 0.01% of the resin, and most preferably the powder compositions have no liquid or viscous petroleum products present.
A general preferred range for such ingredients would include 50-90% by weight polymer (preferably 70-86% by weight), 5-50% by weight crosslinking agent (preferably 14-30% by weight), 0 to 3% flow agent, preferably 0.3 to 3% by weight flow agent (more preferably ) 0.5 to 1.5% by weight flow agent), 0.2 to 4% degassing agent, preferably 0.2 to 2.0% degassing agent (more preferably 0.3 to 1.5% by weight), and 0.8 to 8% by weight leafing aluminum flake (preferably 0.8 to 6%, or 0.8 to 3% by weight).
The cured coatings of the present invention have been found to provide coatings with high gloss. As noted in U.S. Pat. No. 5,045,114, the gloss provided in that system was about 357 at 20 degrees and 469 at 60 degrees (e.g., Table IV, Example IV). The commercial product using that process technique (milling with mineral spirits present) provides a gloss of about 550 at 20 degrees. In the practice of the present invention, dry powder coating compositions having gloss levels over 400, over 450, over 500, over 550 and over 600, up to levels exceeding 900 have been obtained. The powder coating compositions also exhibit reduced agglomeration as compared to compositions made by some other methods without using paste aluminum. For example, fewer than 8%, and preferably fewer than about 5% of the flakes are agglomerated with other flakes in the practice of the present invention. By non-agglomerated with the leafing flakes of the present invention it is meant that less than 15% of the surface area of a flake is adhered (not merely overlying the other flake, but actually bound thereto) to another flake, thereby masking its surface. An agglomerated flake therefore has at least 15% of its surface covered by another flake in an adhered manner, rather than merely lying on top of the flake. Gloss may be measured, and has been measured in data presented herein, on a BYK-Gardner gloss meter, which had been calibrated for white and black on calibration tiles specific for the gloss meter. Multiple readings were taken (and unless otherwise indicated, averages reported) with 3 readings for 3×5 panels, 5 for 4×6 panels, 7 for 4×9 panels and 8 readings for 6×12 inch panels. The procedure used was that indicated by the manufacturer in which the desired incident angle was selected by the appropriate button on the gloss meter, a statistic mode was selected, the sample platform was lowered, the statistic function was cleared, the sample was placed on the sample platform under a spotlight, the sample platform was raised, and the results were read.
As noted, the suppression of the temperature in the process may be effected by any convenient means. The most convenient means is the provision of cooling apparatus which surrounds the mixing area. The high speeds of the mixing apparatus, and the high shearing forces of the fins, blades or propellers, creates a large amount of heat within the system. It is primarily this heat which causes the temperature to tend to rise above the T g of the resin. In some processing equipment for the high speed mixing of powder coating compositions, heating systems are actually provided to increase the temperature or increase the rate at which the higher temperatures are achieved, or to bond the powdered resins and flakes. This heating above the T g of the resin is actually contrary to the benefit of the mixing procedure as found in the practice of the present invention. Any conventional cooling system which is capable of controlling the temperature of the mixing mass during the high speed mixing is useful. The heat may be withdrawn from the container holding the mixing mass, the mixing mass directly, or by cooling the air or environment around the mixing mass. The process of the present invention, by selection of available commercial equipment, can be performed in either a batch or continuous process manner.
EXAMPLES
Background Study Examples 1-4
The effects of varying shear rates, tip speeds (which have a relationship to work performed on the system), duration of the blending process, and the number of repetitions of the blending process were examined. A standard mixture of organics (the thermally curable resin) and leafing aluminum pigments were used in all of the evaluative examples. The resin selected and the leafing aluminum flake used were provided as a resin premix in all examples, unless otherwise indicated as:
78.9% by weight Polyester resin (isophthalic anhydride (IPA)/glycol; e.g., as manufactured by DSM, UCB, EMS or Ruco, Inc.) having a T g of about 55-63° C.,
17.3% by weight E-caprolactam blocked isophorone diisocyanate,
1.2% by weight Acrylic flow agent,
0.8% by weight benzoin degassing agent, and
1.8% by weight leafing aluminum flake.
Volumes of the resin premix were placed into a laboratory Welex Blender (model no. TGAHK8), a specific blending speed selected (1,500; 2,000; 2,500; and 3,000 revolutions per minute [r.p.m.]), the resin premix was heated up by the energy of the blending action on the resin mass. Blending was stopped and the aluminum oxide fluidizer was added to the heated resin mass before the T g of the resin was reached (a targeted temperature of about 48° C. was chosen), and the mixture was blended for an additional fifteen seconds to assure that the fluidizer was evenly distributed. The process is usually performed with the flakes and the resin already in the blender prior to initiation of the high shear mixing, at least for the purpose of convenience. The materials may be added to the blender as alternative layers in the blender prior to initiation of the blending. The powder mass was then dumped from the blender and subsequently used in a standard powder coating procedure at various coating thickness values, and data (including gloss at 20 and 60 degrees) taken. The results are shown in TABLE 1 below.
Sample 1, 2,500 grams resin premix, 0.2% by weight aluminum oxide fluidizer, 1500 r.p.m., resin temperature of 48.2° C. upon addition of aluminum oxide fluidizer, and end temperature of 46.7° C.
Sample 2, 2,500 grams resin premix, 0.2% by weight aluminum oxide fluidizer, 2000 r.p.m., resin temperature of 48.2° C. upon addition of aluminum oxide fluidizer.
Sample 3, 2,500 grams resin premix, 0.2% by weight aluminum oxide fluidizer, 2500 r.p.m., resin temperature of 50.0° C. upon addition of aluminum oxide fluidizer.
Sample 4, 2,500 grams resin premix, 0.2% by weight aluminum oxide fluidizer, 3000 r.p.m., resin temperature of 49.3° C. upon addition of aluminum oxide fluidizer.
TABLE 1______________________________________SAMPLE THICKNESS ATI DOI 20° GLOSS 60° GLOSS______________________________________#1 2.5-3.2 mil 41 191 247 #2 2.6-2.8 mil 36 189 243 #3 2.8-3.3 mil 42 206 260 #4 2.8-3.6 mil 37 195 248______________________________________
Sample 1 was blended for 21.5 minutes, sample 2 for 8 minutes, sample 3 for 5 minutes, and sample 4 for 2.75 minutes.
The shear forces provided by the blending at 2,500 r.p.m. appeared to provide the best reflectance results on this composition in a single pass through the blender with the Temperature of the mixing mass maintained below the T g of the resin.
Examples 5-10
The effects of repeated blending of the resin/flake mixture at 2,500 r.p.m. while maintaining the temperature of the mixing mass below the T g of the resin was then examined. All of the samples were performed without the addition of fluidizing agent. Sample 5 comprised the mixture with a single pass through the blender for 4.5 minutes at 2,500 r.p.m. with an endpoint temperature of 48.2° C.
Sample 6 took the end product of Sample 5 and performed a second blending operation for 5 minutes at 2,500 r.p.m. with an endpoint temperature of 48.0° C.
Sample 7 took the end product of Sample 6 and performed an additional blending operation for 4.5 minutes at 2,500 r.p.m. with an endpoint temperature of 48.0° C.
Sample 8 took the end product of Sample 7 and performed an additional blending operation for 4.5 minutes at 2,500 r.p.m. with an endpoint temperature of 48.2° C.
Sample 9 took the end product of Sample 8 and performed an additional blending operation for 4.5 minutes at 2,500 r.p.m. with an endpoint temperature of 49.2° C.
Sample 10 took the end product of Sample 9 and performed an additional blending operation for 4.0 minutes at 2,500 r.p.m. with an endpoint temperature of 48.1° C.
TABLE 2______________________________________SAMPLE THICKNESS 20° GLOSS 60° GLOSS______________________________________#5 4.0-4.8 mil 228 332 #6 4.3-4.9 mil 280 376 #7 3.0-3.3 mil 321 400 #8 2.2 mil 378 431 #9 4.2-4.6 mil 422 444 #10 4.6-4.9 mil 483 475______________________________________
Although there were some variations of gloss values within each sample dependent upon the thickness of the coatings (e.g., in Sample #3, a coating thickness of 2.8-3.3 mil provided 200 gloss of 206 and 600 gloss of 260), the clear trend of the data shows that increasing the amount of high shear blending (here by repetition of the blending operations) while maintaining the temperature of the mixing mass below the T g of the resin improved the gloss.
A commercially available product produced by ball milling of wet (mineral spirits) aluminum flake in resin produced 3.0-3.4 mil coatings having 20° gloss of 555 and 60° gloss of 379. The coating, however, had a fairly grainy appearance.
Examples 11-28
The effects of cooling the blending equipment to moderate the temperature of the mixing mass so that the T g of the resin was never exceeded, and the blending could be continued indefinitely was examined. 3750 g batches of resin (the same as used in Example 1) and leafing aluminum were premixed and used in each example. A sample of the powder was removed from the Mixaco™ blender at 10 minute intervals, sieved through a 140 mesh screen, sprayed through an Anoda™ electrostatic cup gun with the setting at 2 Barr pattern air/1 Barr flow air/60 kv, the powder being sprayed to a thickness of 2.0-4.0 mil and measured for gloss at 20 and 60 degrees (as the average of three readings), with the powder cured at 400° F. for fifteen minutes. Four different blade configurations were used in the examples, 1) a single straight blade (dispersion blade), 2) two straight blades (90 degree offset), 3) a single 30° bent blade, and 4) a single straight blade (dispersion blade) and a single bent blade in a ninety degree offset.
______________________________________Single Straight Blade SAMPLE TIME (min.) 20° GLOSS 60° GLOSS______________________________________11 10 238 302 12 20 307 348 13 30 383 382 14 40 418 407 15 50 465 428 16 60 507 449______________________________________
______________________________________Two Straight Blades SAMPLE TIME (min.) 20° GLOSS 60° GLOSS______________________________________17 10 278 328 18 20 365 381 19 30 431 418 20 40 495 449 21 50 592 483 22 60 630 495______________________________________
______________________________________Single Bent Blade SAMPLE TIME (min.) 20° GLOSS 60° GLOSS______________________________________23 10 482 436 24 20 655 503 25 30 742 528 26 40 807 549 27 50 827 553 28 60 856 564______________________________________
______________________________________Single Bent Blade and Single Straight Blade SAMPLE TIME (min.) 20° GLOSS 60° GLOSS______________________________________29 10 432 417 30 20 553 479 31 30 691 508 32 40 764 534 33 50 787 544 34 60 817 547______________________________________
The single bent blade composition was continued for 70, 80 and 90 minute intervals, and some marginal increase in gloss was found (e.g., maximum increase of 20 in 20° gloss, and maximum increase of 12 in 60° gloss.
A Hosokawa Bepex Turbulizer™ blender was also run at 4,000 r.p.m. and cooled for various samples, with similar results (e.g., 20° gloss range of 603-628 and 60° gloss range of 490-500). A single run at 4,200 r.p.m., without any attempt at optimization, also displayed reduced gloss from the best results at 2,500 to 4,000 r.p.m. (e.g., 20° gloss range of 379-389 and 60° gloss range of 397-402). This apparatus was run in a continuous operation with mix fed into one end and blended product removed at the other end.
The efficiency of the different blenders can be seen in the difference between relative values between the hp/pound and the hp-hours/pound used by the equipment.
______________________________________BLENDER TYPE RANGE, Horsepower-hours/pound______________________________________WELEX ™ 0.02-0.06 MIXACO ™ 0.05-0.10 BEPEX ™ 0.05-0.10______________________________________
It is believed that at least 0.01 horsepower-hours/pound, preferably at least 0.02 horsepower-hours/pound, more preferably at least 0.04 or 0.05 horsepower-hours/pound, still more preferably at least 0.07 or at least 0.08 horsepower-hours/pound, and most preferably at least 0.09 or at least 0.10 horsepower-hours/pound should be applied to the mixture of binder and flake while maintaining the temperature of the mixture mass below the T g or melt temperature of the polymer to gain the best benefits of the present invention. Of course, a limit to gloss will be attained, but values in excess of 800 and 900 have been achieved, as shown by the examples.
It is to be noted that the energy rates listed above are higher input rates than the natural heat loss rate of the blenders without modification. All blenders had to be run with external cooling means. In these experiments all blenders were run with cooling water flowing through a jacket system, with the jacket surrounding the mixing chamber. Any other means of removing heat and cooling the mixing chamber are functional, of course. The mixture mass, usually through cooling of the mixing chamber or other areas of the blender could be performed by indirect or direct cooling with a jacket system. An indirect system could be a jacket or coil (e.g., or electronic Peltier system) on the outside of the mixing chamber, or a jacket or other cooling system within the mixing chamber (but insulated so that it would not react with the materials within the chamber). The cooling fluid could be a liquid or gas. Direct cooling would encompass such actions as the addition of inert components into the mixture mass within the blender. Heat would be removed by evaporation of the inert material. The use of cooled gas flows, liquid nitrogen, dry ice, and the like would be one way of effecting that process. Chilled air (not preferred because of the oxygen content) or relatively inert gases could be directed through the blending chamber to remove the heat generated.
The following examples evaluate the effects that variations in the blades within a single mixer may have on the gloss development while maintaining the temperature of the mixing mass below the T g of the polymeric resin. A Mixaco batch blender was used in the examples. A similar resin/flake composition as used in Examples 11-28 were used here.
______________________________________ 30° Blade 45° Blade Time Avg. Temp. 30° Blade Avg. Temp. 45° Blade Minutes O.sub.C 20 degree gloss O.sub.C 20 degree gloss______________________________________ 0 1 79 1 79 30 26 475 22 415 45 35 636 26 520 60 33 694 26 615 75 35 733 24 702 90 38 651 24 749______________________________________
Other efforts were made to attempt to evaluate controlling conditions on the provision of high gloss compositions from these materials. The same materials which provided a high gloss composition in the practice of the present invention with high shear mixing with temperatures maintained below the Tg of the resin would not produce gloss of similar quality when materials were first extruded, then ground in a conventional grinder with temperatures maintained below the Tg of the resin. For example, 20 degree gloss less than 100 was typically obtained.
Different reflective particles, such as manufactured by US Aluminum, Obron Atlantic and Toyal leafing flakes were used in high shear mixing processes. Resin particle compositions of both blocked polyurethane compositions and polyester/triglycidylisocyanurate were used with success.
Example 29
This Example evaluates the use of a pasted aluminum reflective particle (flake) in a high shear mixing process according to the practice of the present invention. A composition comprising 98.5% by weight of the same polymer resin particles used in Example 1 and 1.5% by weight of pasted aluminum flake was used in this example. A Welex blender (fully cooled by a water flow jacket) was used with 20 minutes at 2500 rpm, 30 minutes at 3000 rpm, 10 minutes at 3500 rpm, and 15 minutes at 4000 rpm. Samples were taken at different time intervals to evaluate the reflectivity at 20 and 60 degree gloss.
______________________________________Sample No. Time (min.) 20° Gloss 60° Gloss R.P.M.______________________________________1 5 224 313 2500 2 10 257 360 2500 3 15 253 368 2500 4 20 253 373 2500 5 25 281 381 3000 6 30 284 390 3000______________________________________
As can be seen from these data, the gloss at 20 degrees increased most significantly with the pasted flake powder composition at the higher mixing speeds under cooled conditions. These pasted flake compositions were not optimized. Using 2.6% by weight pasted aluminum flake in a different curable resin composition with 50 minutes at a lower mixing rate (2500 rpm in the fully cooled Welex mixer) produced only a gloss of 99 at 20 degrees. Higher concentrations of pasted flakes seemed to provide higher gloss under similar mixing conditions.
The powder coating compositions with liquid petroleum products (e.g., from the pasted aluminum flakes) tend to be tacky and prone to agglomeration over time as compared to the non-pasted systems. | A method of manufacturing powder coating compositions, the powder coating compositions, and cured coatings made from the coating compositions are described. The method of preparing the coating compositions comprises combining a preformulated thermally softenable resin powder (having a defined T g ) and a reflective pigments (such as a non-leafing or leafing metallic flake, mica, optically variable pigment, and the like) and then mixing the powder and flake under high shear conditions and assuring that the average temperature of the mixture remains below the T g of the resin during the high speed mixing process. The powder coating compositions are free of pasted aluminum flake and comprise thermally softenable resin particles having a number average diameter of between 15 and 60 microns, leafed metallic flakes having a number average maximum diameter of between 4 and 45 microns, said powder when coated onto a metallic surface in a thickness of at least 10 microns and melted and cured, providing a reflectivity of at least 400 at 20 degrees viewing angle. The resultant coating may also be free of the plasticizer, solvent or thickener used in pasted aluminum. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/434,137, filed on May 1, 2009, which is a continuation of U.S. patent application Ser. No. 11/039,908 filed on Jan. 24, 2005, now abandoned, which was a divisional of U.S. patent application Ser. No. 09/925,433, filed on Aug. 10, 2001, now U.S. Pat. No. 6,855,154, which claims priority to U.S. Provisional Patent Application No. 60/224,361, filed Aug. 11, 2000. The entire disclosures of these prior applications are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to systems and processes for treating an aneurysm, and more particular to an endovascular system and process for collapsing an aneurysm.
BACKGROUND OF THE INVENTION
[0003] Aneurysm treatments have been proposed using a wide variety of processes and devices, which have enjoyed various levels of success and acceptance. Such systems and processes include aneurysm clips, intravascular coils, intravascular injections, detachable intravascular balloons, and the like.
[0004] These prior devices, however, have proven to be difficult to employ, oftentimes do not lend themselves to deployment in all sizes of aneurysms, can be imprecise in their deployment, their installation can be very time consuming, risk rupture of the aneurysm because they increase its size, can risk recanalization and/or migration of the device in the patient's vasculature, and may not treat the mass effect that the aneurysm may have caused. Furthermore, the presence of adhesions in the aneurysm makes it difficult to collapse the aneurysm. There therefore remains an unmet need in the art for systems and processes which do not suffer from one or more of these deficiencies.
SUMMARY OF THE INVENTION
[0005] According to a first aspect of the invention, a method of treating an aneurysm in a patient comprises the steps of advancing a compressed clip through the distal end of a catheter and into the aneurysm, expanding portions of the clip inside the aneurysm, and folding a distal segment of the clip on itself together with the adjacent wall of the aneurysm as it becomes dislodged from the stretching bar.
[0006] According to a second aspect of the invention, a system useful for treating an aneurysm in a blood vessel of a mammalian patient, the aneurysm having a neck, a wall, and a cavity, comprises an elongated shaft having a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, and including at least one lumen extending therethrough, and a self-expanding frame positioned at the distal end of the shaft, the frame including a plurality of self-expanding sections and at least one joint, each of the plurality of self-expanding sections having an unbiased, expanded condition and a biased, collapsed condition, each of the plurality of self-expanding sections being foldable about one of the at least one joint when in a biased, collapsed condition.
[0007] According to a third aspect of the invention, a catheter useful for accessing a vascular location adjacent to an aneurysm, comprises a hollow shaft including a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, a port in a distal portion of the shaft, and including at least one lumen extending therethrough. and an inflatable member mounted on the shaft adjacent to the shaft distal end, the inflatable member in fluid communication with the shaft at least one lumen, the inflatable member including a proximal end, a distal end, and a wall between the proximal end and the distal end which extends to the shaft so that the shaft port is directly exposed to the exterior of the balloon, the wall delimiting a central working channel.
[0008] According to a fourth aspect of the invention, a method of treating an aneurysm in a patient comprises the steps of advancing a compressed clip through the distal end of a catheter and into the aneurysm, expanding portions of the clip inside the aneurysm, and folding a distal segment of the clip on itself together with the adjacent wall of the aneurysm as it becomes dislodged from the stretching bar.
[0009] Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of embodiments constructed in accordance therewith, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention of the present application will now be described in more detail with reference to preferred embodiments of the apparatus and method, given only by way of example, and with reference to the accompanying drawings, in which:
[0011] FIGS. 1 a and 1 b illustrates longitudinal and cross-sectional views of an exemplary embodiment of an apparatus in accordance with the present invention;
[0012] FIG. 2 illustrates the apparatus of FIG. 1 in use according to an exemplary method;
[0013] FIG. 3 illustrates a step later than that illustrated in FIG. 2 in the exemplary method;
[0014] FIGS. 4 a and 4 b illustrate a step later than that illustrated in FIG. 2 in the exemplary method, utilizing two embodiments of apparatus illustrated in FIG. 1 ;
[0015] FIGS. 5 a and 5 b illustrate two embodiments of apparatus in accordance with the present invention;
[0016] FIGS. 6 a - 6 c illustrate successive steps of use of an apparatus in accordance with the present invention;
[0017] FIG. 7 illustrates a vascular aneurysm after collapse thereof in accordance with the present invention;
[0018] FIG. 8 illustrates a distal end of yet another embodiment of a device in accordance with the present invention;
[0019] FIG. 9 illustrates a side elevational view of a catheter in accordance with the present invention;
[0020] FIG. 10 illustrates a top plan view of the catheter of FIG. 9 ;
[0021] FIGS. 11-17 diagrammatically illustrate several steps of treating an aneurysm in accordance with an aspect of the present invention;
[0022] FIGS. 18-21 diagrammatically illustrate several steps of treating an aneurysm in accordance with another aspect of the present invention;
[0023] FIG. 22 illustrates a distal end of yet another embodiment of a device in accordance with the present invention; and
[0024] FIGS. 23-28 diagrammatically illustrate several steps of treating an aneurysm in accordance with yet another aspect of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Apparatus and methods in accordance with the present invention have numerous advantages over prior aneurysm clips and methods. Among these advantages, immediate closure of an aneurysm can be achieved with a relatively easy-to-use method. The apparatus and methods can be used to treat all aneurysms regardless of the size or the neck width, and can achieve precise locational deployment and decreased procedure time. The risk of rupture can be decreased, since the aneurysm volume is never increased. Additionally, occlusion of the aneurysm neck can be achieved by a balloon in case rupture does occur. Decreased risk of distal embolization, little or no risk of recanalization or migration, strengthening of the arterial wall at the site of the aneurysm, good visualization of the device during and after deployment, and immediate elimination of any mass effect the aneurysm may have caused can also be achieved.
[0026] Referring to the drawing figures, like reference numerals designate identical or corresponding elements throughout the several figures.
[0027] FIGS. 1 a and 1 b illustrate a first exemplary embodiment of a system in accordance with the present invention. The system 100 includes a triple lumen catheter 102 having a sidewall 104 and three lumenae 106 , 108 , 110 extending longitudinally therethrough. An inflatable member 112 , such as a balloon. is positioned adjacent a distal end 114 of the catheter, and is in fluid communication with one of the three lumenae, e. g., lumen 106 . A collapsible element or clip 116 is removably mounted to the distal end of the catheter and is movable between a retracted and collapsed condition, illustrated in FIG. 1 a, and an extended and expanded condition, illustrated in FIGS. 4 a , 4 b , 5 a , and 5 b . In order to effect collapse and expansion of the clip 116 , a longitudinally movable stretching bar 118 extends proximally from the distal end of the catheter, and preferably extends both within the clip 116 and the one of the catheter lumenae, e.g., lumen 108 .
[0028] The system 100 also preferably includes a flexible portion in the distal end of the catheter 102 so that the catheter can more easily navigate the sometimes tortuous paths encountered during endovascular procedures. By way of example and not of limitation, a spring 120 can be incorporated into the distal portions of the catheter 102 , preferably proximal of the balloon 112 , to permit the catheter to more easily flex and bend. A pair of steering wires 122 are attached to the catheter distal to the flexible portion 120 and to a steering mechanism or station 124 at the proximal end of the catheter. Steering mechanisms for catheters have previously been proposed in the patent literature, and therefore a detailed description of station 124 will be omitted herein.
[0029] The catheter 102 also preferably includes at least one, and more preferably, several distal side perfusion holes 126 which are in fluid communication with one of the three lumenae, e.g., lumen 110 . The catheter also includes a one way valve 128 positioned distally of the balloon 112 and also in fluid communication with one of the lumenae. Valve 128 is oriented to permit a vacuum drawn in the catheter to suction through the valve, for purposes which will be explained in greater detail below. In accordance with one preferred embodiment, both the side holes 126 and the valve 128 are in fluid communication with the same lumen; because the one way valve 128 only permits flow into the catheter through the valve, perfusion of fluid, e.g. contrast agent, through the side holes 126 will not exit out the catheter through the valve.
[0030] Turning briefly to FIGS. 5 a , 5 b , and 6 a - 6 c, further details of clips in accordance with the present invention are illustrated. In general, clips in accordance with the present invention are releasable from the catheter or other deployment device inside an aneurysm. The clips also have a collapsed condition into which the clips are biased by their own structures, and an expanded condition into which the clips must be moved. FIGS. 5 a and 5 b illustrate two different versions of a clip 116 in an expanded condition, with the stretching bar 118 extending through the catheter 102 and through the clip 116 . As illustrated in FIGS. 5 a and 5 b , the stretching bar 118 also includes a thread, wire, or the like 130 which is connected to the distal most end of the stretching bar and extends proximally through the catheter 102 , preferably within the stretching bar itself.
[0031] The stretching bar 118 includes at least one, and preferably several telescoping sections 132 a - f of decreasing outer diameter. Thus, section f can slide into section e, section e into section d, and so forth, when the wire 130 is pulled proximally. The clip 116 includes at least one, and preferably several rings 134 a - f which are releasably held on the outer surface of the stretching bar 118 , e.g., by a friction fit, a frangible coupling, or the like. To each ring 134 a set of arms 136 are attached so that the arms can articulate and fold in toward the stretching bar, in a manner somewhat similar to an umbrella. An outer trellis or covering 138 extends between the opposite ends of the arms.
[0032] In order to deploy the clip 116 , the distal end of the catheter 102 is positioned in the neck of an aneurysm, as illustrated in FIG. 2 . The stretching bar, which is already in its own expanded condition, is pushed distally, carrying with it the collapsed clip 116 . As the clip exits the distal end of the catheter, as through a distal port 140 , successive sections of the clip expand outward until the clip is fully exposed and outside of the catheter. The wire 130 is then pulled proximally, causing the sections of the stretching bar to telescope into one another, with the distalmost section 132 f moving proximally first into the next most distal section 132 e. As the distalmost end of the section 132 f moves into the distalmost end of the section 132 e, the ring 134 which was received on the section 132 f is pulled off of the stretching bar, leaving that distalmost section of the clip collapsed proximally against the adjacent section. The wire 130 is pulled proximally until each of the sections 132 has telescoped into the adjacent section, causing a collapsing cascade of the clip sections proximally. When the proximalmost section of the stretching bar has been retracted, the clip is left fully collapsed and separated from the stretching bar and the deployment device, e.g., catheter 102 . FIGS. 6 a - c illustrate successive views of this serial collapse of the clip from a side view, while FIG. 7 schematically illustrates the completely collapsed clip in situ.
[0033] According to additional embodiments, the releasable connections between the arms 136 and the stretching bar 118 can be formed as twist locks, meltable connections, for which a resistive heater is positioned at each arm and voltage source is connected thereto, or the like as will be readily appreciated by one of ordinary skill in the art.
[0034] Turning now to FIG. 8 , yet another embodiment of a clip in accordance with the present invention is illustrated. Clip 200 includes a longitudinally extending hollow, preferably cylindrical shaft 202 which extends to a closed, and optionally sealed, distal end 204 . A self-expanding frame 206 is mounted about the distal portions of the shaft 202 , and includes a number of segments which can fold about a number of collapsing joints 208 . Preferably, the joints 208 are positioned in an alternating fashion on different sides of the clip 200 , so that the clip can be folded up in an accordion-type manner. When each of the segments of the frame 206 fold about each joint 208 , that segment folds onto an adjacent segment, as described in greater detail below. Each joint 208 includes a laterally extending leaf spring which has an unbiased, V-shaped orientation and a biased, flat orientation. Because of the presence of the spring in each joint 208 , each segment is biased to fold upon itself, as illustrated in the drawing figures. A stiffening wire, stretching bar, or mandrel 210 extends through each of the segments of the frame, and prevents the springs of each of the joints 208 from folding each segment upon itself, as described in greater detail below.
[0035] The stiffening wire or stretching bar 210 extends longitudinally through the shaft 202 . The wire or bar 210 allows the practitioner to straighten or laterally collapse the frame 206 ; that is, when the bar/wire/mandrel 210 is pushed distally against the distal end 204 , the frame 206 can be stretched and collapsed, and proximal retraction removes this force on the frame and permits the frame to expand. Self-expanding frames are well known to those of skill in the art, such as those known for use in constructing vascular stents, and therefore the constructional details of frame 206 are omitted from this description for brevity's sake. As described in greater detail below, the self-expanding frame is constrained from expanding when advanced through the vasculature because the frame is carried in a catheter shaft which is sized to prevent the frame from expanded until the clip is moved out of the catheter. Such a practice is also known in the art of vascular stents, which are typically carried in a collapsed condition inside a carrier catheter, and thereafter pushed out of the catheter which permits them to expand.
[0036] Preferably, at least portions of the shaft 202 are configured so that upon rotation of the shaft about the longitudinal axis, the shaft is released from the frame 206 . By way of example and not of limitation, distal portions of the shaft 202 can include a detent which will pass through correspondingly sized and shaped holes in the sections of the frame 206 only when the shaft is rotated to align the detent and hole. Other suitable mechanisms will be readily apparent to those of skill in the art.
[0037] FIGS. 9 and 10 illustrate side elevational and top plan views, respectively, of a catheter 220 which is useful for accessing and positioning a clip, such as clip 200 , in an aneurysm 10 . The catheter 220 includes a longitudinally extending shaft 222 dimensioned and formed of materials so that it can traverse the vasculature of the patient to be positioned immediately next to an aneurysm that the practitioner intends to treat. An inflatable balloon 224 is mounted on the distal end of the shaft 222 , and includes proximal 226 and distal 228 inflatable portions. A central working channel 228 is formed in the balloon 224 by a portion 246 of the wall of the balloon extending inward to the shaft 222 . Preferably, at least one, and more preferably several radiopaque markers 230 are located around the central working channel 228 so that its position in the patient can be monitored fluoroscopically.
[0038] The catheter 220 also preferably includes a mechanism or the like which directs a clip radially outward through the working channel 228 when the clip is pushed distally through the shaft 222 . According to one exemplary embodiment, this mechanism can be a ramp shaped surface formed in the lumen of the shaft 222 , so that when the clip is pushed distally through the shaft, the clip's distal motion is converted into radial motion out of the shaft and into the working channel. According to yet another exemplary embodiment, a deflectable tube 234 can be mounted on the shaft at the base of the working channel 228 , and a steering thread 232 is attached to the tube 234 . The steering thread extends proximally through the shaft 222 and exits the shaft or is otherwise made available to the practitioner to manipulate. Upon proximal pulling on the steering thread 232 , the tube 236 can be deflected to point toward the central working channel 228 , thus directing any clip, such as clip 200 , which is pushed through the tube 234 into the working channel.
[0039] Several lumenae extend through the shaft 222 . A suction lumen 236 extends from a distal port 248 , located where the working channel 228 meets the shaft 222 , to a proximal fitting or suction end 238 , and includes a lock 242 . The lock 242 is operable to seal the lumen 236 so that a relative vacuum can be maintained in the lumen. For example, lock 242 can be a stopcock valve. A proximal fitting 244 leads to another lumen of the shaft 222 , and is the lumen which leads to the deflectable tube 234 and is the lumen in which the clip, e.g., clip 200 , is longitudinally advanceable. Thus, the clip 200 can be loaded through the fitting 244 or the tube 234 , into the shaft 222 with proximal portions of the clip extending proximally out of the fitting 244 . In this orientation. the clip is in a collapsed condition because the internal dimensions of the lumen are selected to constrain the clip from self-expanding. Thereafter, the clip can be advanced distally, through the tube 234 and laterally into the working channel 228 .
[0040] FIGS. 11-17 illustrate several steps in an exemplary method in accordance with the present invention which utilizes clip 200 and catheter 220 , and are described in more detail below.
[0041] Turning now to FIG. 22 , yet another embodiment of a clip in accordance with the present invention is illustrated. Clip 300 includes a longitudinally extending hollow, preferably cylindrical shaft (not illustrated) which contains a wire/bar/mandrel 308 to move the clip into an aneurysm. A pair of circular or oval self expanding frames 302 , 304 are mounted on the end of the clip 300 , and include a spring activated collapsing joint 306 . See FIG. 27 and FIG. 28 . As in other embodiments herein, radiopaque markers 310 are preferably provided on the frames to assist in positioning the clip 300 in the aneurysm neck 12 . The diameter of the self expanding frames is broader than the diameter of the neck. See FIG. 25 through FIG. 28 . The joint 306 includes at least one, and preferably a plurality (two are illustrated) leaf springs, as described above. The springs are oriented with both ends on one lateral side of the each of the frames, Le., a first V-spring is mounted on the right side of the frames as illustrated in FIG. 22 , and a second V-spring is mounted on the left side of the frames. Thus, when unconstrained by a carrying catheter, such as catheter 220 , the frames tend to open up to the orientation illustrated in FIG. 22 and form a barrier 312 . The clip is therefore self expanding. The frames support a lattice 309 A and 309 B. The alignment of the lattice cross structure 309 A of the distal frame 302 can be offset from the alignment of the lattice cross structure 309 B for the proximal frame 304 . Hence when the frames are brought together by collapse of the joint 306 , the combined frames form a barrier across the aneurysm neck. See FIG. 28 .
[0042] Another aspect of the present invention includes methods of treating an aneurysm. Several embodiments of methods in accordance with the present invention will now be described with reference to several of the drawing figures, and with reference to several of the exemplary devices described herein. The methods of the present invention are not restricted to the particular devices described herein, but may be performed using other devices which are employable into an aneurysm cavity and onto the outer surface of which the aneurysm wall can be collapsed. By way of example and not of limitation, vascular coils, such as those described in the numerous U.S. patents to Guglielmi et al (see, e.g., U.S. Pat. No. 6,083,220), can be used as a device in the methods of the present invention.
[0043] A first exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, the steps of:
1. Perform a road-mapping arteriogram with measurement of the three dimensional size of an aneurysm 10 and its neck 12 within the small and tortuous neurovascular systems. 2. Access the aneurysm neck using a steerable catheter, e.g. catheter 102 . 3. Lock the distal end of the catheter in a position perpendicular to the center of the neck transverse axis. 4. Slowly inflate a balloon mounted on the distal end of the catheter with a diluted contrast medium up to the previously measured size of the neck (see FIG. 2 ). 5. Verify complete occlusion of the neck 12 by injection of contrast agent through side holes in the catheter positioned just proximal to the balloon, and simultaneously applying suction through a one-way valve at the distal end of the catheter. When no inflow of the contrast into the catheter is demonstrated together with deformation of the aneurysm with the suction, the aneurysm neck is completely closed. 6. With the neck completely closed, continue suction to almost complete collapse of the aneurysm by creating a vacuum within the aneurysm (see FIG. 3 ). 7. Obtain transverse and longitudinal measurement of the aneurysm, e.g. using MRI, CT scan, or the like. 8. Advance a compressed clip, the size of which has been chosen according to the previous measurements, through the distal end of the catheter. The clip, which is constructed using a principal similar to a self-expanding vascular stent, will start to expand as it is advanced into the aneurysm. The transverse axis of the clip is preferably maintained parallel to the longitudinal axis of the artery 14 from which the aneurysm 10 is arising (see FIGS. 4 and 5 ). 9. Maintain the vacuum within the aneurysm with continuous suction to ensure adherence of the aneurysm wall to the sides of the clip ( FIG. 6 a ). 10. Begin proximal pulling of the wire or thread mounted within the stretching bar to telescope the very distal segment into the next proximal segment (see FIG. 6 b ). 11. The distal segment of the clip, which folds on itself if not stretched from both ends as described above, will start folding on itself together with the adjacent wall of the aneurysm as it becomes dislodged from the stretching bar (see FIG. 6 c ). The aneurysm wall is held to the outside of the clip by the suction. 12. By repeating the process described in steps 10 and 11 , successive segments of the stretching bar and clip will continue to fold and complete collapse of the aneurysm will be achieved. (see FIG. 7 ) The catheter can then be withdrawn.
[0056] A second exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, the steps of:
1. Perform a road-mapping arteriogram. 2. Obtain measurements of the aneurysm, the neck of the aneurysm, and the parent artery. 3. Using a transvascular approach, e.g., a right femoral approach, position the balloon catheter 200 in the parent artery (using the guidance of the radiopaque markers on the periphery of the central working channel) with the distal segment of the balloon distal, e.g., immediately distal, of the aneurysm neck, and the proximal segment proximal, e.g., immediately proximal, to the aneurysm neck (see FIGS. 9-11 ). 4. Slowly inflate the balloon to achieve occlusion of the parent artery both proximal and distal to the neck. 5. Pull the steering thread within the catheter shaft to direct the steerable section of the catheter to a position as close and as perpendicular as possible to the neck (see FIG. 12 ). 6. Apply a moderate amount of suction using a suitable device, e.g., a syringe attached to a lock mounted on the proximal end of the catheter to decompress the aneurysm; activate the lock to maintain the relative vacuum in the aneurysm (see FIG. 10 ). 7. Stiffen the distal segment of the aneurysm clip with the stiffening wire by pulling on the proximal segment of the wire and then push it until it reaches the sealed top of the clip. 8. Push both the stiffening wire and the clip into the aneurysm cavity, firmly holding both of these elements together; the self-expanding frame of the clip will start to expand as the clip is deployed (see FIG. 13 ). 9. Apply strong suction through the catheter to collapse the aneurysm wall completely around the expanded clip (see FIG. 14 ). 10. Turn off the vacuum lock at the proximal end of the catheter while applying strong vacuum to the catheter lumen to ensure that a vacuum is maintained within the aneurysm to assist, and preferably ensure, that the aneurysm wall adheres to the outside of the clip. 11. Start pulling the stiffening wire through the sealed proximal end of the catheter to release the most distal segment of the clip, which will fold onto itself about the joint because of the action of the springs in the joints, together with the adjacent aneurysm wall which is held by the vacuum (see FIGS. 15 , 16 ), which may be at least in part assisted by the force of the vacuum pushing inward on the frames of the clip. 12. Repeat steps 10 and 11 so that successive segments or sections of the clip continue to fold and at least partial, and preferably complete, collapse of the aneurysm will be achieved (see FIG. 17 ). 13. Rotate the shaft, e.g., counterclockwise, to dislodge the shaft from the collapsed segment(s) of the clip.
[0070] A third exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, the steps of the above described second embodiment, with the following modification. The clip is positioned at the neck of the aneurysm and the very proximal end of the aneurysm segment. Only the portion of the clip that is in the aneurysm is folded, leaving the rest of the aneurysm decompressed but not fully collapsed onto the outer surface of the clip (see FIGS. 18-21 ). This and other aspects of the invention can be particular useful in the treatment of aneurysms which include adhesions, which make complete collapse of the aneurysm wall difficult because they make the wall less pliable.
[0071] A fourth exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, utilizing the clip 300 (see FIG. 22 ) in the following manner and including the steps of:
1. Perform steps 1 - 6 as described in the second embodiment above. 2. Introduce the distal segment of the clip 300 to a point just distal of the neck of the aneurysm 10 , i.e., just inside the aneurysm cavity (see FIG. 25 ). FIG. 25 shows the diameter of the expanded distal segment of the clip to be larger than the diameter of the aneurysm neck 12 . 3. Apply strong suction and lock it in to maintain vacuum in the aneurysm cavity. 4. Pull the distal segment 302 of the clip to push (fold) down the aneurysm neck 12 (see FIG. 26 ). 5. Introduce the proximal segment 304 of the clip into the parent artery 14 , e.g., through a catheter 220 , just proximal of the neck and permit or cause the joint of the proximal segment to collapse thereby compressing the neck (see FIG. 27 ). 6. Dislodge the pushing wire by turning it, e.g., in a counterclockwise direction (see FIG. 28 ). The double frame of the proximal and distal clip occludes the flow of blood into the aneurysm. The double frame comprises a barrier 312 to an aneurysm created by the self expanding distal and proximal segments installed and forming a barrier across the aneurysm neck. The combined effect of the proximal and distal frame of the clip is to form a permanent barrier across the neck of the aneurysm to impede or obstruct the blood flow to the inside sac of the aneurysm leading to thrombosis and occlusion of the aneurysm. Also the lattice of the frame acts as a scaffolding for the lining of the vessel to grow causing permanent sealing of the aneurysm.
[0078] As will be readily appreciated by one of skill in the, the present invention also extends to the combination of a deployment catheter, such as catheter 220 , with any of the embodiments of the aneurysm clips described herein to access and treat an aneurysm.
[0079] While the invention has been described in detail with reference to preferred embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. Each of the aforementioned published documents is incorporated by reference herein in its entirety. | A collapsing clip including a plurality of collapsed self expanding wire frame segments is contained within the distal end of a catheter. The clip can be delivered to the neck of an aneurysm within the neurovascular system using a catheter. The collapsing clip impinges the distal and proximal framed wire segments onto the neck of the aneurysm. The framed wire segments are inter positioned so that the diamond shaped spaces between the wires are substantially blocked. The neck of the aneurysm is blocked by the distal and proximal framed wire segments forming a barrier. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a miniature motor exhibiting reduced sliding loss on the end face of an oil-impregnated bearing which receives a thrust load of a rotor generated due to rotation of the motor, as well as to a method for manufacturing the miniature motor.
2. Description of the Related Art
A miniature motor having a worm reduction-gear functions such that a drive torque output from the motor is transmitted to a worm via a motor shaft, from the worm to a worm wheel, which is a helical gear, and from the worm wheel to an external load via an output shaft of the worm wheel. Upon startup of clockwise or counterclockwise rotation of such a miniature motor having a worm reduction-gear connected to an external load, a thrust force of the worm joined to the motor shaft acts in such a direction as to withdraw the shaft from a motor casing. As a result, the motor rotates while a washer on the shaft is pressed against a bearing.
In such a case where a worm is employed in a torque transmission system for transmission of torque to an external load, rotation of a motor induces a thrust load, and in some cases the minimum startup voltage of the motor increases due to a sliding loss associated with a frictional resistance between a washer on a rotor and the end face of an oil-impregnated bearing subjected to the thrust load. When the motor involving such a sliding loss is to be started, a greater amount of power is required as compared with a case of a motor that does not involve such a sliding loss. Therefore, in the case where a miniature motor having a worm reduction-gear is used to drive, for example, an air conditioner damper for use in an automobile, the miniature motor has involved a problem of failure to start up when the battery voltage is low as a result of, for example, low temperature.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the above-mentioned problem, and to provide a miniature motor in which, even when a thrust load is induced by rotation of the motor, a sliding loss on the end face of an oil-impregnated bearing subjected to the thrust load is reduced to thereby avoid a problem of an increased minimum startup voltage of the motor or a problem of large power required for startup of the motor.
Another object of the present invention is to provide a method for manufacturing such a miniature motor.
To achieve the above object, the present invention provides a miniature motor comprising a closed-bottomed cylindrical motor casing having a cylindrical bearing support portion projecting from a central portion of the bottom of the motor casing, a motor-casing-side bearing accommodated in the bearing support portion, a casing cover fitted to an open end portion of the motor casing, a casing-cover-side bearing accommodated in a central portion of the casing cover, and a rotor rotatably supported by means of the motor-casing-side bearing and the casing-cover-side bearing. The end face of the motor-casing-side bearing is concentrically polished in a circumferential direction at at least a portion which, when the rotor is urged toward the motor casing, abuts a washer provided on a shaft of the rotor.
The present invention also provides a method for manufacturing a miniature motor, comprising the steps of providing the motor casing having the motor-casing-side bearing accommodated in the bearing support portion of the motor casing; setting the motor casing in a casing rest while a motor-casing-side bearing is accommodated in the bearing support portion of the motor casing; coaxially pressing a rotating polishing rod against the end face of the motor-casing-side bearing at at least a portion which abuts a washer provided on a shaft of the rotor, so as to concentrically polish the portion in a circumferential direction; and attaching the rotor in a completed form and the casing cover to the motor casing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing an example of a miniature motor having a worm reduction-gear to which the present invention is applicable;
FIG. 2A is an enlarged sectional view of “A” of FIG. 1 ;
FIG. 2B is a view showing the end face of a bearing which abuts an adjustment washer;
FIGS. 3A and 3B are views similar to FIGS. 2A and 2B , respectively, showing a modified example of the bearing;
FIG. 4 is a view for explaining a method for concentrically polishing the end face of the bearing; and
FIG. 5 is a graph showing measurement results.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a view exemplifying a miniature motor having a worm reduction-gear to which the present invention is applicable. FIGS. 2A and 2B show the detail of “A” of FIG. 1 . Such a miniature motor can be used in an electric unit for driving, for example, an air conditioner damper for use in an automobile. In FIGS. 1 and 2 , reference numeral 1 denotes a closed-bottomed cylindrical motor casing of metal. A magnet 2 , which provides stator magnetic poles, is fixedly attached to the inner circumferential surface of the motor casing 1 . A bearing support portion 6 , which is a cylindrical protrusion for accommodating a bearing 3 , is integrally formed at a central portion of the bottom of the motor casing 1 . A casing cover 22 of metal is fitted to an open end portion of the motor casing 1 . A support portion is integrally formed at a central portion of the casing cover 22 . A bearing is press-fitted into the support portion, and a shaft stopper is accommodated within the support portion. Brushes 21 and terminals connected to the brushes 21 are attached to the casing cover 22 via a resin holder. A core 12 , windings 13 , and a commutator 14 are mounted on a shaft 11 , thereby forming a rotor. Reference numeral 7 denotes a bushing of resin or metal for axially positioning the rotor. Reference numeral 8 denotes an oil stoppage washer. An adjustment washer 15 is sandwiched between the oil stoppage washer 8 and the bearing 3 .
A worm 16 , which partially constitutes a reduction gear, is firmly fitted to a distal end portion of the shaft 11 projecting outward from the motor casing 1 . A helical gear 17 , which serves as a worm wheel, is meshed with the worm 16 . Drive torque output from the motor is transmitted to the worm 16 via the shaft 11 , from the worm 16 to the helical gear 17 in the reduction gear, and from the helical gear 17 to an external load via an output shaft of the helical gear 17 .
The above-described configuration is of an ordinary miniature motor, except for the structure of the bearing 3 . The structure of the bearing 3 according to the present invention will be described with reference to FIGS. 2A and 2B showing the detail of “A” of FIG. 1 . FIG. 2A is an enlarged sectional view of “A” of FIG. 1 . FIG. 2B shows the end face of the bearing 3 which abuts the adjustment washer 15 . As shown in FIGS. 2A and 2B , the bearing 3 of a sintered alloy is accommodated in the cylindrical bearing support portion 6 , which is integrally formed at a central portion of the bottom of the metallic motor casing 1 .
The bearing 3 is configured such that the entirety of the oil-impregnated end face thereof is substantially flat. In order to reduce frictional resistance on the self-lubricating end face of the bearing 3 , at least a portion of the end face which abuts the washer 15 is concentrically polished so as to be smoothed in the circular direction. That is, the end face of the bearing 3 is not necessarily polished over the entire surface, but may be polished up to a diameter that is not greater than the outside diameter of the bearing 3 and slightly greater than the outside diameter of the adjustment washer 15 . FIG. 2B shows the end face of the bearing 3 . In FIG. 2B , reference numeral 4 denotes a concentrically polished portion, and reference numeral 5 denotes an unpolished portion.
FIGS. 3A and 3B are similar to FIGS. 2A and 2B , respectively, but show a modified example of the bearing 3 . The bearing 3 of FIGS. 3A and 3B is configured such that a portion of its end face which abuts the adjustment washer 15 protrudes from the end face. The top face of the protrusion is flat. A through-hole is formed in the bearing 3 so as to allow the shaft 11 to extend therethrough. Only the flat top face of the protrusion abuts the adjustment washer 15 . In application of the present invention to the bearing 3 , the entire top face of the protrusion is concentrically polished.
FIG. 4 is a view for explaining a method for concentrically polishing the end face of the bearing 3 . The motor casing 1 is set in a casing rest 30 while the bearing 3 is accommodated in the bearing support portion 6 of the motor casing 1 . Next, a rotating polishing rod 31 is coaxially pressed against the end face of the bearing 3 to thereby concentrically polish the end face. In this case, the diameter of a portion to be polished is greater than the outside diameter of the adjustment washer 15 and not greater than the outside diameter of the bearing 3 . Polishing brings about a level difference between the polished portion and an unpolished portion. When the level difference between the polished portion and the unpolished portion falls within a range of 1 μm to 5 μm, the polishing amount can be judged to be optimal, because the rough end face of the bearing 3 can be completely smoothed without involvement of adverse effect on productivity, and an oil-producing porous portion can be left. When the level difference is insufficient, the end face remains rough, and thus an expected effect of polishing is not attained. When the level difference is excessively large, dust of polishing increases and raises a problem (e.g., generation of unusual noise). Further, polishing time increases, thereby impairing production efficiency. The above-mentioned degree of polishing is also applicable to the bearing 3 of FIG. 3 . Since polishing reduces the height of the protrusion, the degree of polishing can be judged from the reduction of the height.
Preferably, the casing rest 30 , in which the motor casing 1 is set, is not firmly fixed, but is rendered movable within a predetermined range, so that the end face of the bearing 3 is in full contact with that of the polishing bar 31 at all times in the process of polishing. Such movable arrangement can be attained, for example, in the following manner: the casing rest 30 is elastically supported in a support 32 by use of spring. If the casing rest 30 is immovable, and the motor casing 1 or the bearing 3 is inclined, the end face of the polishing rod 31 will unevenly abut that of the bearing 3 . As a result, polishing cannot be performed in a complete circular area, but is performed in a semicircular or arcuate area.
Since only one end face of the bearing 3 must be polished, a selected end face of the bearing 3 is usually polished before attachment to the motor casing 1 . However, this method requires an operator or system to confirm which end face has been polished, when the polished bearing 3 is attached to the motor casing 1 , thereby impairing production efficiency. Therefore, polishing (in the circular direction) the bearing 3 after attachment to the motor casing 1 allows better handling and provides better production efficiency as compared with a case of polishing the bearing 3 before attachment to the motor casing 1 .
FIG. 5 shows the results of a test conducted on motors which were configured under the following conditions.
Dimensions and characteristics of motor: motor casing diameter: 24 mm; motor casing length: 31 mm; shaft diameter: 2 mm; no-load rotational speed: 3000 rpm; stopping torque: 100 gf·cm; rated voltage: 12 V
Bearing: oil-impregnated, sintered iron-copper bearing (an oil-impregnated, sintered porous bearing mainly formed of metal powder); outside diameter: 5.5 mm; inside diameter: 2.0 mm; thickness: 2.0 mm; lubricant: poly-α-olefin oil
Washer: material: polyethylene terephthalate (PET); outside diameter: 3.4 mm; inside diameter: 2.0 mm; thickness: 0.2 mm
The motors which were configured under the above conditions according to the present invention were measured for the minimum startup voltage while the rotor was withdrawn toward the motor casing by a force of about 2 kgf. The measurement results are shown in FIG. 5 above the rightmost expression “POLISHED (CIRCULARLY) (PRESENT INVENTION).” As mentioned above, the motors are of a rated voltage of 12 V. However, FIG. 5 shows that the motors are started at an average voltage of 6.2 V, a maximum voltage of 7.1 V, and a minimum voltage of 5.5 V. Thus, the motors exhibit sufficient performance according to the standard (9 V or less).
The measurement results shown in FIG. 5 above the leftmost expression “UNPOLISHED (CONVENTIONAL)” are of the motors which were configured and measured under the same conditions as those mentioned above except that the bearings were not polished. FIG. 5 shows that the motors are too high in startup voltage to satisfy the standard (9 V or less).
The measurement results shown in FIG. 5 above the central expression “POLISHED (LINEARLY) (REFERENCE EXAMPLE)” are of the motors which were configured and measured under the same conditions as those mentioned above except that the bearings were polished linearly; specifically, the end faces of the bearings were polished linearly (the bearings were arranged linearly and polished along the linear direction of arrangement). In general terms, the motors show good measurement results; i.e., the motors satisfy the standard (9 V or less). However, some of the motors fail to satisfy the standard. In a word, mere polishing is insufficient. Polishing must be performed in the circular direction.
Employment of the present invention reduces a sliding loss on the bearing even when the washer is pressed against the bearing, so that the minimum startup voltage does not rise to a problematically high level, thereby avoiding a failure to start when the battery voltage drops as a result of low temperature. | A miniature motor includes a closed-bottomed cylindrical motor casing having a cylindrical bearing support portion projecting from a central portion of the bottom of the motor casing, a motor-casing-side bearing accommodated in the bearing support portion, a casing cover fitted to an open end portion of the motor casing, a casing-cover-side bearing accommodated in a central portion of the casing cover, and a rotor rotatably supported by means of the motor-casing-side bearing and the casing-cover-side bearing. The end face of the motor-casing-side bearing is concentrically polished at at least a portion which, when the rotor is urged toward the motor casing, abuts a washer provided on a shaft of the rotor. The above structure reduces sliding loss on the end face of an oil-impregnated bearing which receives a thrust load of the rotor generated due to rotation of the motor. | 5 |
GOVERNMENTAL INTEREST
The invention described herein may be manufactured, used and licensed by or for the Government for Governmental purposes without the payment to me of any royalty thereon.
BACKGROUND OF THE INVENTION
Various means have been used in the past to control both the flow rate and the stream pattern of fluids from a nozzle. Prior art designs required an operator in order to adjust flow rate and pattern to work against the line pressure. In high pressure applications such as used in fire hose nozzles, large forces and/or sophisticated and complex mechanisms are frequently required in order to control the flow and stream pattern settings of the valve. Prior art large high pressure fire hose nozzles generally require several men to hold and control the flow rate and stream pattern settings. The complexity of prior art adjustable nozzle designs has prohibited the use of independent selection of flow and spray pattern control designs to low cost garden hose nozzle applications.
PRIOR ART STATEMENT
The present invention greatly furthers the state of the art disclosed in the U.S. Pat. No. 2,799,466 and patent application, Ser. No. 897,304 filed on Apr. 18, 1978, now U.S. Pat. No. 4,194,694. The present device provides for an infinitely variable independently controlled fluid flow rate from the nozzle full open to full closed position without the need for a separate shut off valve, and for a similar independently controlled stream pattern from fine spray to straight stream. In contradistinction the above references allow only infinitely variable flow from the valve full open to full closed positions and stream pattern which cannot be varied independent of the flow rate.
SUMMARY OF THE INVENTION
This invention relates to a device for independently controlling both fluid flow and stream pattern in a high pressure fluid control valve nozzle. Flow control is achieved by utilizing a vented piston valve member and balanced fluid pressure forces on the fore and aft sections of a piston valve member to open and close the nozzle orifice with a minimum of operator effort. Stream pattern control is achieved by utilizing an axially located fluid stream pattern deflector located at a fore end of a nozzle seat member and attached to a threaded control rod with an aft end control knob which is easily rotated to vary the fluid stream pattern. While the flow control and stream pattern control systems are interrelated into a single overall design, each may be operated independently from the other. The present invention solves the problems aforementioned in the prior art high pressure adjustable nozzles by providing independent fluid flow control and stream pattern control with a relatively small and inexpensive device which is simple to operate, small of size and weight, and reliable in performance due to reduced complexity of construction.
The present invention provides an independently operated adjustable fluid flow control means and independently adjustable stream pattern control means for a high pressure fluid control valve nozzle. Fluid flow rate is variably controlled by creating a line pressure unbalanced on fore and aft sections of a vented piston valve member. The stream pattern is independently variably controlled in a range between fine spray and straight stream by a stream pattern deflector.
This invention also provides an adjustable nozzle which has an independently operated adjustable fluid flow control means and independently adjustable stream pattern control means for a high pressure fluid control valve nozzle wherein the cost for manufacture is substantially reduced from prior art.
The present invention provides an independently operated adjustable fluid flow control means and an independently adjustable stream pattern control means for a high pressure fluid control valve nozzle of substantially reduced weight and size from prior art nozzles having similar flow and stream pattern capabilities.
In addition the present invention provides an independently operated adjustable fluid flow control means and independently adjustable stream pattern control means for high pressure fluid control valve nozzle which does not require substantial operator force to overcome high line pressure.
The present invention provides an independently operated adjustable fluid flow control and adjustable stream pattern control means for a high pressure fluid control valve nozzle which is more adaptable for remote control operation.
The present invention provides an independently operated adjustable fluid flow control means and independently adjustable stream pattern control means for a high pressure fluid control valve nozzle which can be economically adapted to garden hose nozzle design.
Further it is an object of this invention to provide an independently operated adjustable fluid flow control means and independently adjustable stream pattern control means for a high pressure fluid control valve nozzle which can conserve the use of water by allowing the operator to reduce the flow rate but still maintain the desired stream pattern.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following descriptions taken in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawing is a partial cutaway longitudinal diametral cross-sectional view of an adjustable high presssure fire hose nozzle configuration.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing, the adjustable high pressure cylindrical shaped nozzle body member 10 is hydraulically fixedly attached to an internally threaded hose connector 12 by two or more "U" shaped tube handles 14. A fluid flow control cap 16 has an internally threaded control cap thread 18 therein. Fluid flow control cap 16 is threadly disposed on externally threaded nozzle body aft end 20 of the exterior of nozzle body member 10. An internally threaded fluid flow control sleeve 22 is fixedly and axially disposed in fluid flow control cap 16. The fluid flow control sleeve 22 is slidably fitted into an axially located aft sleeve hole 24 in nozzle body member 10. An "O" ring 26 is operatively positioned in nozzle body member aft end 20 to seal and prevent leakage of the flowing fluid contained in rear nozzle body cavity 28. A nozzle seat member 30 is threadedly attached to the internally threaded nozzle body member fore end 32 of the nozzle body member 10 with an annularly shape sealing gasket 34. Sealing gasket 34 is positioned between the members 30 and 10 respectively to prevent leakage of the flowing fluid. A cylindrical piston valve member 36 is axially slidably disposed within the nozzle body member 10. The piston fore end 38 cooperates with the nozzle seat member 30 in controlling fluid flow from a full closed to full open position. The piston fore end 38 is conically tapered so that it makes circular contact with a conically convergent nozzle section 37 at the nozzle seat 40. The piston valve member 36 conically concave aft end 42 cooperates with the fluid flow control sleeve 22 whose position relative to the aft end 42 is determined by rotation of the fluid flow control cap 16. A plurality of radially positioned piston guide pins 44 are located on a middle outside surface section of the piston valve member 36. Piston guide pins 44 help center the piston valve member 36 within the nozzle seat member 30 to insure uniform circular flow cross-sectional area across the nozzle seat 40. When in an open position, a controlled clearance space 46 is maintained between the exterior wall 48 of cylindrically shaped piston shoulder 50 of the piston valve member 36 and the interior wall 52 of the central cavity of nozzle body member 10 to allow fluid to enter rear nozzle body cavity 28 and to exert pressure on the aft end 42 of piston valve member 36. A cylindrical fluid stream pattern deflector member 54 is slidably axially located within piston valve member 36 and fixedly connected at rear end 57 to the control rod forward end 56 of a fluid stream pattern control rod 58 by a transversly positioned connector pin 60. The control rod aft end 62 of control rod 58 is connected to a fluid stream pattern control knob 64. A control rod threaded section 66 is operatively disposed on a center portion of the fluid stream pattern control rod 58 to cooperate with the internally threaded fluid flow control sleeve 22 to slidably position the fluid stream pattern deflector member 54 in an axially disposed piston deflector slide bore 68. The flowing fluid, as indicated by arrow 70 enters internally threaded hose connector 12 then divides as shown by arrows 72 and proceeds into a plurality of "U" shaped tube handles 14 at the tube handle inlets 74 and exits the "U" shaped tube handles 14 at the tube handle outlets 76 in the direction shown by arrow 78. The flowing fluid flows through the piston fluid flow-passage 80 and exits through the nozzle seat member 30 when piston valve member 36 is in an open position. A positioning pressure balance on the fore and aft ends 38 and 42 of piston valve member 36 is obtained by a fluid pressure relief passage across the control sleeve fore end 82 of the fluid flow control sleeve 22 and the fluid flow control sleeve piston seat 84 of the piston valve member 36. A pressure relief piston passage aft end bore 86 in piston valve member 36 allows fluid pressure to be relieved into the piston deflector slide bore 68. Fluid passes then into a plurality of radially positioned pressure relief passage holes 88 of the fluid stream pattern deflector member 54 and exits through the deflector pressure relief passage divergently shaped fore end 90 via axial relief bore 91.
In operation, the fluid flow is adjusted by rotating the fluid flow control cap 16 and the fluid stream pattern is adjusted by rotating the fluid stream pattern control knob 64. In this manner, the fluid flow and the fluid stream pattern are independently adjusted in any combination of fluid flow from closed to full open and fluid stream pattern from fine spray to straight stream.
When the fluid flow control cap 16 is rotated to the closed position, as shown, the fluid pressure source when attached to hose connector 12 allows the fluid pressure to act through the "U" shaped tube handles 14 into the annular piston fluid flow passage 80. From passage 80 the fluid pressure is contained on the surface 39 of piston valve member 36 which is in contact with the nozzle seat member 30 at the point of the nozzle seat 40. The fluid pressure also acts in the rear nozzle body cavity 28 between the aft end 42 of the piston valve member 36 and the nozzle body member 10 since the controlled clearance space 46 between the interior wall 52 of the nozzle body member 10 and the exterior wall 48 of the piston valve member 36 provides a restricted fluid passage. With the fluid flow control cap 16 in the closed position, the fluid pressure cannot be relieved through the relief passage consisting of piston passage aft end bore 86, piston deflector slide bore 68, deflector pressure relief passage holes 88 and finally deflector pressure relief passage fore end 91, since the control sleeve fore end 82 of fluid flow control sleeve 22 of the fluid flow control cap 16 is in contact with piston valve member 36 at the fluid flow control sleeve piston seat 84. In the above described fluid flow closed position the fluid pressure in rear nozzle body cavity 28 which is equal to the flowing fluid inlet pressure to the piston fluid flow passage 80, acts over the wetted cross-sectional area of the aft end 42 of piston valve member 36 causing a closing force larger than the opposing opening force caused by the same pressure acting over the smaller wetted cross-sectional area of the fore end 39 of piston valve member 36 between the contact line of the nozzle seat 40 and the full diameter of the exterior wall 48.
When the fluid flow control cap 16 is rotated to any selected open position, the control sleeve fore end 82 is moved to the left and away from the fluid flow control sleeve piston seat 84. This allows the fluid pressure in rear nozzle body cavity 28 to be vented through pressure relief passage aft end bore 86, piston deflector chamber bore 68, pressure relief passage holes 88 and deflector pressure relief passage fore end 91. With a reduced fluid pressure in rear nozzle body cavity 28 the closing forces on the piston valve member 36 drop below the opening forces and the piston valve member 36 moves off its nozzle seat 40 allowing fluid flow to exit from the nozzle seat member 30. The piston valve member 36 continues to move to the selected open position until a force balance on each side of the piston valve member 36 is reached. In this balanced position a throttling of the relief passage across the flow control sleeve seat 84 causes the reduced pressure in cavity 28 needed to balance the opening and closing forces on the piston valve member 36. The reduced pressure results since the cross-sectional area of the controlled clearance between the interior wall 52 and the exterior wall 48 is less than the cross-sectional area of the pressure relief passage down stream of the fluid flow control sleeve seat 84. By turning the fluid flow control cap 16 in a closing direction, pressure is increased in rear nozzle body cavity 28 upsetting the force balance on the piston valve member 36 with a resulting movement of the piston valve member 36 to a force balance position which results in reduced fluid flow.
With any selected fluid flow setting of the fluid flow control cap 16 described above, the fluid stream pattern control knob 64 may be rotated to change the fluid stream pattern exiting from nozzle seat member 30. Since the fluid stream pattern deflector member 54 is rigidly attached to fluid stream pattern control rod aft end 62 which in turn is rigidly attached to the fluid stream pattern control knob 64, rotation of the fluid stream pattern control knob 64 causes a movement with resulting change in position of the fluid stream pattern deflector member 54. The intentional movement of the fluid stream pattern deflector nozzle 54 to the right or left by clockwise or counterclockwise rotation of the fluid stream pattern control knob 64, results from engagement of the control rod thread section 66 with the thread inside the fluid flow control sleeve 22. Moving the fluid stream pattern deflector member 54 to the left or onto the piston deflector slide bore 68 causes the flowing fluid stream pattern to change from a spray position toward a straight stream position which is reached when the fluid stream pattern deflector member 54 is moved completely into the aft end 69 of piston deflector slide bore 68.
It is noted that parallel positioned spray baffles 92 on the inside fore end of the nozzle seat member 30 assist the fluid stream pattern deflector member 54 in deflecting back a portion of the fluid spray to eliminate obtaining a normally undesirable hollow spray cone pattern.
It is also noted that the low operating torque forces and the readily accessible positions of the fluid flow control cap 16 and the fluid stream pattern control knob 64 make the addition of state of the art remote actuators simple and inexpensive. Remote control of the fluid flow and the stream pattern are required when fire hose nozzles are placed in positions such as high snorkel ladders and platforms where firemen may not venture due to fire and other hazards. It is further noted that the fluid stream pattern control knob 64 and the control rod thread 66 can be simply eliminated and replaced by a state of the art piston actuator, not shown, with the capability of cycling the fluid stream pattern deflector member 54 rapidly in and out of the deflector chamber 68 with resulting rapid cycling of the fluid stream pattern from straight stream to spray. This is advantageous in remote agricultural irrigation applications and may be advantageous in fire fighting and other applications. A flow indicator such as an arrow, not shown, may be placed on the fluid flow control cap 16 and matched to flow rate settings marked on the outside exposed portion of the aft end of the nozzle body member 10. These flow rate settings allow an operator to select a desired flow rate, generally given in gallons per minute (gpm). Also included as a setting is a "flush" position which is normally at the maximum flow position and is used by the operator to flush out any obstructions or foreign matter that may have entered the fire hose and lodged in the nozzle seat 40. An indicator on the fluid stream pattern control knob 64 not shown, can be used to alert an operator as to which direction to turn control knob 64 in order to obtain the straight stream and spray (sometimes referred to as fog) positions.
While there has been described and illustrated specific embodiments of the invention, it will be obvious that various changes, modifications and additions can be made herein without departing from the field of the invention which should be limited only by the scope of the appended claims. | An adjustable fluid control valve utilizes a fluid flow controlling piston in cooperation with a rotatable cap which causes fluid pressure to move the piston to any desired nozzle fluid flow control setting from closed to full open. The piston contains a fluid stream deflector which moves in cooperation with a manually adjusted knob to independently vary the nozzle fluid stream pattern to any desired adjustment from fine spray to straight stream. The simple, easy and quick adjusting cap and knob allows the fluid control valve operator to independently select and change fluid flow rates and nozzle spray patterns as desired. | 1 |
FIELD OF THE INVENTION
[0001] This invention relates to proximity sensing systems and methods. Such systems and methods are useful for managing power consumption in an electronic device, as well as for other purposes.
BACKGROUND OF THE INVENTION
[0002] Power management is becoming increasingly important as electronic devices place greater reliance on battery power. Portable computers, personal data assistants (PDAs), tablet computers, cellular phones, pagers, and wireless computer peripherals are only a few examples. While components of such devices are becoming increasingly power hungry, the demand for longer intervals between battery replacement or recharging has increased. Indeed, many devices are often turned on for ready usability but left idle for significant periods of time. Accordingly, there is an increasing need for systems and methods that reduce or slow battery depletion.
[0003] Wireless peripheral devices intended for use with a host computer are becoming more common. In particular, cursor control (pointing) devices such as a computer mouse can be made wireless by inclusion of a battery power source within the device and providing a wireless data link to a personal computer or other device via, e.g., an infrared or RF transmitter/receiver pair. Without effective power management, however, continuously operating a wireless peripheral can rapidly deplete the device's battery power, thereby requiring frequent battery replacement or recharging.
[0004] A common method of minimizing power consumption is to configure a device to “sleep” when it is not being used. In other words, a device may turn off many of its components during periods of non-use, and turn those components back on when the device is used. In a wireless computer mouse employing mechanical encoder wheels moved by a roller ball, sleep can occur by powering down the mouse's transmitter and receiver components, as well as other components not currently needed. The mouse can then periodically sample the encoder wheels for movement. When a change is detected in encoder wheel position between sampling intervals, the device “wakes up” and reactivates any powered-down components. This sampling occurs at a rate that is fast in comparison to human response time (on the order of 50 millisecond (msec) intervals); moving the mouse thus “wakes” the device without a perceptible delay. After experiencing a designated period of no motion, the mouse can then go back to sleep. The inactive intervals between sampling allow the average power use during “sleep” to be very small.
[0005] In another line of technological development, cursor control devices utilize optical surface tracking systems in lieu of conventional encoder wheel arrangements. Exemplary optical tracking systems, and associated signal processing techniques, include those disclosed in commonly owned U.S. Pat. No. 6,172,354 (Adan et al.) and copending application Ser. No. 09/692,120, filed Oct. 19, 2000, and Ser. No. 09/273,899, filed Mar. 22, 1999. Optical tracking can provide more reliable and accurate tracking by eliminating moving parts (e.g., a ball and associated encoder wheels) which are prone to malfunction from the pick-up of dirt, oils, etc. from the tracked support surface and/or a user's hand. On the other hand, optical tracking requires considerable power for driving the circuitry used to illuminate a trackable surface and to receive and process light (image information) reflected from the trackable surface.
[0006] Although optical mice and other cursor control devices are an improvement over devices relying upon mechanical encoder wheels, sampling mouse motion as a method of “waking” a sleeping optical mouse is problematic. To determine motion, the imager must be powered and compare at least two successive images to determine motion. This requires a motion detector's illuminating LED to be turned on for a significant amount of time. The resultant power use is thus greater than that of a sleeping mechanical mouse. There is thus a need for alternative methods and systems that sense when a mouse (or other input device) is needed and wake the device. Proximity detection is one such alternative. Instead of sampling the mouse's (or device's) motion detector elements for movement, detection of a user's approaching hand can be used as an indicator that the mouse must wake up.
[0007] Various types of user proximity detectors are known and used in power management systems and other applications. For example, Mese et al. U.S. Pat. No. 5,396,443 discloses power saving control arrangements for an information processing apparatus. More specifically, the Mese et al. patent describes various systems for (1) detecting the approach (or contact) of a user associated medium to (or with) the apparatus; (2) placing a controlled object of the apparatus in a non-power saving state when such contact or approach is detected; and (3) placing the controlled object in a power saving state when the presence of the user associated medium (i.e., a stylus pen or part of a user's body) is not detected for a predetermined period of time. The '443 patent describes various types of approach/contact sensors. Among these, various “tablet” type sensor systems are described, including electromagnetic, capacitance, and electrostatic coupling tablets. In one embodiment, a contact or approach detecting tablet, and a flat display panel, may be integrally formed with a housing of the information processing apparatus.
[0008] Sellers U.S. Pat. No. 5,669,004 discloses a system for reducing power usage in a personal computer. More specifically, a power control circuit is disclosed for powering down portions of a personal computer in response to user inactivity, and for delivering full power to these portions once user activity is detected via one or more sensors. The components to which power is reduced (or removed) are components which can respond almost immediately to being turned on. On the other hand, components which require a period of time to come up to full operation (e.g., disk drive motors, monitor, main processor) are driven to full power. In the primary embodiment that is disclosed, the sensor is a piezoelectric sensor fitted into a keyboard. Sellers discloses that sensors may be positioned at other locations on the computer (a monitor, mouse, trackball, touch pad or touch screen) and that various other kinds of sensors (capacity, stress, temperature, light) could be used instead of piezoelectric sensors.
[0009] Commonly owned U.S. patent application Ser. No. 09/948,099, filed Sep. 7, 2001, discloses capacitive sensing and data input device power management systems and methods. In the disclosed embodiments, capacitive proximity sensing is carried out by detecting a relative change in the capacitance of a “scoop” capacitor formed by a conductor and surrounding ground plane. The conductor may be a plate provided in the form of an adhesive label printed with conductive ink. Charge is transferred between the scoop capacitor and a relatively large “bucket” capacitor, and a voltage of the bucket capacitor is applied to an input threshold switch. A state transition from low to high (or high to low) of the input threshold is detected, and a value indicative of the number of cycles of charge transfer required to reach the state transition is determined. The presence or absence of an object or body portion in close proximity to or in contact with a device can be determined by comparing the value with a predetermined threshold. The predetermined threshold can be adjusted to take into account environmentally induced changes in capacitance of the scoop capacitor.
SUMMARY OF THE INVENTION
[0010] The present invention provides a simple system and method for proximity detection representing an alternative to the capacitive sensing systems and methods described in Ser. No. 09/948,099. The invention is described by way of a particular implementation in a wireless computer mouse using optical tracking, but can be implemented in other forms and in other contexts. The invention detects proximity of a hand, other body part or other object by measuring output from a phototransistor or other device that generates, in response to an electromagnetic illumination, a voltage or other output that varies with time of illumination. When electromagnetic radiation from an adjacent illuminating source is reflected by an object into the receptor, the output of the receptor rises more quickly than the output would rise in response to ambient conditions alone. The output is sampled at multiple points during a sampling period, and an indication of the relation of each sample to a threshold value is recorded. To compensate for detector output rise over time that would occur in ambient conditions (i.e., with no reflected energy from the adjacent illumination source), two series of samples are recorded. The first series is taken in ambient conditions (the illuminating source off), and the second series is taken with the illuminating source activated. The sequence of recorded output indications from the “on” series is compared to the sequence of recorded output indications from the “off” series, and if the change is above a designated level, an object is determined to be near.
[0011] In one embodiment of the invention, a phototransistor (PTR) is used as a receptor, and an infrared light emitting diode (IR LED) is used as an illumination source. A series of bits is recorded with the IR LED off, with a “0” bit stored for each sample where the PTR voltage is below a threshold voltage and a “I” stored for each sample where the PTR voltage is at or above the threshold voltage. A second series of bits is recorded with the IR LED on, and the results compared. If the difference in “1” bits is above a designated level, an “object-near” condition has occurred (i.e., object is recognized to be near).
[0012] According to another aspect of the invention, a second sensor (e.g., a second receptor/illuminating source pair) is added, and an object-near condition is not recognized unless both sensors detect the object. In this manner, false detections can be avoided when a user device (e.g., a computer mouse) is positioned next to a stationary object (e.g., a coffee cup or other desktop object). According to another aspect of the invention, the voltage sample series can be tested for noise or other anomalous results, and the series discarded if corrupted.
[0013] These and other aspects of the invention will be apparent from the following description of the invention, taken in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a diagrammatic perspective view showing location of components in one embodiment of the invention.
[0015] [0015]FIG. 2 is a schematic diagram of the detection circuitry in one embodiment of the invention.
[0016] [0016]FIG. 3 is a graph illustrating differences in the voltage rise time for a PTR when an object is near and when an object is far.
[0017] [0017]FIG. 4A is a graph showing voltage rise over time for a PTR in a condition of low ambient light with no hand in proximity, and with the IR LED inactive.
[0018] [0018]FIG. 4B is a graph showing voltage rise over time for a PTR in a condition of low ambient light with no hand in proximity, and with the IR LED active.
[0019] [0019]FIG. 5A is a graph showing voltage rise over time for a PTR in a condition of low ambient light with a hand in proximity, and with the IR LED inactive.
[0020] [0020]FIG. 5B is a graph showing voltage rise over time for a PTR in a condition of low ambient light with a hand in proximity, and with the IR LED active.
[0021] [0021]FIG. 6A is a graph showing voltage rise over time for a PTR in a condition of high ambient light with no hand in proximity, and with the IR LED inactive.
[0022] [0022]FIG. 6B is a graph showing voltage rise over time for a PTR in a condition of high ambient light with no hand in proximity, and with the IR LED active.
[0023] [0023]FIG. 7A is a graph showing voltage rise over time for a PTR in a condition of high ambient light with a hand in proximity, and with the IR LED inactive.
[0024] [0024]FIG. 7B is a graph showing voltage rise over time for a PTR in a condition of high ambient light with a hand in proximity, and with the IR LED active.
[0025] [0025]FIG. 8 is a flow chart of the operation of one embodiment of the invention.
[0026] [0026]FIG. 9 is a continuation of the flow chart shown in FIG. 8.
[0027] [0027]FIG. 10 is a continuation of the flow chart shown in FIG. 9 from one branching point.
[0028] [0028]FIG. 11 is a continuation of the flow chart shown in FIG. 9 from another branching point.
[0029] [0029]FIG. 12 is a continuation of the flow charts of FIGS. 10 and 11.
DETAILED DESCRIPTION OF THE INVENTION
[0030] An exemplary application of the invention within a computer input device is presented. Specifically, a wireless, optically tracking computer mouse is described by way of example. However, the invention has much wider-ranging application, and can be used in numerous devices wherein it would be advantageous to conserve battery power during periods of non-use. The invention also has a useful application in other data input devices—portable and non-portable, wireless and wired, self-contained and peripheral (e.g., to a host computer). The invention finds particularly useful application (but is not limited to) battery powered devices which are intermittently used and generally left on over extended periods of time so as to provide ready usability when demand so requires. Such devices include (but are not limited to) portable computers, personal data assistants (PDAs), tablet computers, cellular phones, pagers and wireless computer peripherals, e.g., mice and keyboards. Moreover, the proximity sensing aspects of the present invention are not limited to power management, and can be implemented in virtually any device (data input device or otherwise) where it is desired to determine the presence or non-presence of an object or body portion in close proximity to another object. By way of example and not limitation, this includes many applications where other types of proximity sensors have been used: water valve actuation in toilets; faucets and drinking fountains; automatic door control systems; alarm systems; security lock systems and safety interlock systems, etc.
[0031] [0031]FIG. 1 is a block diagram of one embodiment of the invention implemented in a wireless optical mouse 10 . Although not shown, mouse 10 includes circuitry for communication with a personal computer (PC), optical movement detection means, a battery, and other structures, the details of which are unnecessary for a full understanding of the invention. As is known in the art, mouse 10 is configured to be grasped by a user's hand and moved on a generally flat surface. In order to detect the approach of a user's hand, mouse 10 includes one or more detector pairs, each of which comprises an infrared light emitting diode (IR LED) and a phototransistor (PTR), the operation of which is described in more detail below. A first detector pair 20 , shown in block form, is located on a side of mouse 10 . A second detector pair 30 , also shown in block form, is located on the top of mouse 10 . In order for mouse 10 to wake up, both detector pairs must detect the approach of a user's hand. Requiring detection of approach to the side and to the top of mouse 10 prevents mouse 10 from remaining awake if mouse 10 is “parked” next to a coffee cup or other desktop object that might trigger detector pair 20 located on the side. Detector pairs 20 and 30 are connected to and communicate with electronic circuitry located on circuit board 50 . Although shown as a separate circuit board in FIG. 1, the detection circuitry of the invention could also be located on (or incorporated into) a circuit board having other components and functions. A “tail light” 40 , which illuminates to indicate that the mouse is awake, may also be included. Detector pairs 20 and 30 , tail light 40 and electronic components of circuit board 50 are powered by a battery (not shown).
[0032] [0032]FIG. 2 is a schematic diagram of detector pairs 20 and 30 , tail light 40 and the electronic components of circuit board 50 . Microcontroller 51 can be a PIC16F84-04/P, available from Microchip Technology Inc. of Chandler, Ariz., operating at 4 MHz, with power supplied by voltage source Vdd. In an exemplary embodiment, Vdd=3.5 volts. Microcontroller 51 includes tri-state ports 52 and 53 . The type of microcontroller is not critical to the invention, and indeed, a dedicated controller is not required. Firmware for the invention can be incorporated into the code of a more complex system, and the tri-state ports can be any standard pins on a generic controller or ASIC. The clock for microcontroller 51 is set using resonator 61 , which can be a generic ceramic resonator with internal capacitive loading. Detector pairs 20 and 30 can be IR reflective sensor modules such as the QRD1114 module available from Fairchild Semiconductor Optoelectronics Group (formerly from QT Optoelectronics) of South Portland, Me. Module 20 comprises IR LED 21 and phototransistor (PTR) 22 . Similarly, module 30 comprises IR LED 31 and phototransistor (PTR) 32 . Port 54 (through 2N3904 transistor 62 ) activates tail light 40 (which can be a visible LED) during wake-up mode. Although not needed for operation of the invention, 1 mega ohm resistors 23 and 33 loading phototransistors 22 and 32 can be included so as to provide a convenient location to set an oscilloscope probe for testing. These loads have no effect on the circuit since they are in parallel with tri-state port 52 and 53 input impedances, which are in the range of 20 kilo ohms. Ports 52 and 53 connected to phototransistors 22 and 32 are switched between this 20K impedance input mode and a low impedance output mode which grounds the microcontroller pin. Ports 55 and 56 are drive pins for IR LEDs 21 and 31 , and are toggled high and low to create current pulses in IR LEDs 21 and 31 . This drive current is internally limited at 50 mA by the microcontroller. Resistors (not shown) can be placed in series with IR LEDs 21 and 31 to slow down the rise time of the phototransistors when the IR LEDs are active. This permits the invention to span a wide range of LED efficiencies and PTR sensitivities by matching LED/PTR pair gain to added series resistance. In the described embodiment with no added series resistance, LED pulses last for approximately 50 μsec and are repeated approximately every 50 msec. The rise time characteristics of the QRD1114 are compatible with the timing requirements of a human user interface. The on-time for the sampling time is 50 μsec, and during this period, the voltage ramp for each PTR should cross the threshold voltage for microcontroller 51 when the target (the user's hand) is within 2 inches of the module/sensor and the peak LED current is 50 mA.
[0033] As is known in the art, illumination causes charging of a PTR's internal capacitance. This charging results in a ramping voltage across the PTR as the illumination continues. The rate of charging a PTR's internal capacitance, which corresponds to the slope of the voltage ramp, varies with the intensity of the electromagnetic illumination of the PTR (whether infrared or visible light). In order to reset a PTR's voltage to zero, the PTR is “clamped” by grounding the PTR. When a PTR is “unclamped” and exposed to illumination, it will begin generating a voltage ramp which can be sampled and measured. Referring to FIG. 2, as PTR 22 is unclamped and illuminated, the output voltage of PTR 22 can be incrementally measured at port 52 during a sampling period. For all measured voltages below a threshold voltage V threshold , microcontroller 51 can be configured to store a “0”. For all measured voltages above V threshold , microcontroller 51 can be configured to store a “1”. PTR 32 operates in a similar manner, and its output voltage is measured at port 53 . FIG. 3 is a graph illustrating this operation. For each of measurements 1-5 on the line labeled “object far,” the voltage is below V threshold when sampled at port 52 (or 53 ), and a “0” is stored. For each of measurements 6-8, the voltage is equal to or above V threshold when sampled, and a “1” is stored. If the illumination is more intense, such as may occur when IR radiation is reflected from a nearby object (such as a hand), the voltage rises more quickly, resulting in a steeper ramp. Referring again to FIG. 3, the steeper ramp labeled “object near” describes the voltage rise when a nearby object reflects IR radiation into the PTR, causing more intense illumination. In this case, measuring the voltage at the same time increments results in a “0” stored for measurements 1-3, and a “1” stored for measurements 4-8. If each series of measurements is stored as a sequence of bits, with the first measurement as the most significant bit (MSB) and the last measurement as the least significant bit (LSB), the first series would be “00000111” and the last would be “00011111”. Interpreting these series as 8-bit binary numbers and converting to decimal numbers, the “object near” event produced a sensor response of 31 , and the “object far” event produced a sensor response of 7. As seen in this example, placing the first measurement bit in the MSB position and the last bit in the LSB position, the sensor response maps increasing illumination levels to numbers with increasing value stored in memory.
[0034] This change in voltage rise time can be used to indicate the proximity of an approaching object. If an object is nearby, the voltage rises more quickly, and a stored bit pattern will have more 1's. Because the steepness of a PTR voltage ramp is dependent upon illumination intensity, however, ambient light level can affect the rate at which the PTR's output voltage rises. Referring to FIG. 3, both the “object near” and “object far” ramps could be different if the ambient light were varied. Both ramps would be steeper in higher ambient light and less steep in lower ambient light. If the time increments over which the voltage is measured do not change, the stored bit pattern could vary depending on ambient lighting conditions. Accordingly, the effect of ambient light must be accounted for when using a PTR to detect proximity of an approaching object.
[0035] The invention compensates for the effect of ambient light by measuring PTR voltage during a first interval with the IR LED off, and then measuring PTR voltage during a second interval with the IR LED on. These series of measurements are then compared to determine if there is an object in proximity. This is shown in more detail with reference to FIGS. 4 A- 7 B. FIG. 4A is a graph showing a series of PTR voltage measurements during a condition of low ambient light, with the IR LED off and no hand (or other object) present. The 8 samples in FIG. 4A are taken over 50 μsec, although other sampling periods could be used. As shown in FIG. 4A, all samples under V threshold result in storage of a “0”, and all voltages over V threshold result in storage of a “1.” It should be appreciated that the graph of FIG. 4A (as well as each following graph) is for purposes of explanation, and that no graph is necessarily generated as part of the operation of the invention. Instead, microcontroller 51 records the sampling series as a bit sequence in a register. An example of such a register's contents is shown at the bottom of FIG. 4A, with the first measurement in the MSB and the last in measurement in the LSB. FIG. 4B shows a graph illustrating a second sampling series. Like the series of FIG. 4A, FIG. 4B describes a series of 8 samples taken over a 50 μsec period, in low ambient light and with no hand in proximity. The IR LED is on during the series of FIG. 4B, but because no hand (or other reflective object) is in proximity, no (or virtually no) light from the IR LED is reflected into to the PTR. Accordingly, the graph of FIG. 4B is substantially identical to that of FIG. 4A, and the sampling series bit sequence is also “00000000.”
[0036] [0036]FIG. 5A is a graph showing a series of 8 voltage samples across the same PTR taken over a 50 μsec period in low ambient light, with the LED off and with a hand present. Because a hand in proximity does not appreciably alter the ambient light level, the graph of FIG. 5A is substantially the same to that of FIG. 4A, and the sampling series bit sequence remains “00000000.” FIG. 5B shows a graph illustrating a second sampling series taken over a 50 μsec period shortly after the series of FIG. 5A, but with the IR LED activated. In this case, light from the IR LED is reflected from a nearby hand into the PTR, causing a faster voltage rise rate and steeper ramp. Unlike the series of FIG. 5A, where all samples were below V threshold , only the first 5 samples are below V threshold . The remaining 3 samples are above V threshold , resulting in a sampling series bit sequence (after rotating the sequence of bits from LSB to MSB to place to first sampling bit in the MSB and the last sampling bit in the LSB)=“00000111.”
[0037] [0037]FIG. 6A is a graph reflecting a series of 8 voltage samples across the PTR taken over a 50 μsec period during a condition of high ambient light, with the IR LED off and no hand present. Here, because of the higher ambient light, together with the increased gain common to phototransistors when illumination intensity is increased, the voltage ramp is steeper, and the last 3 samples are above V threshold . Accordingly, a sampling series bit sequence (rotated LSB to MSB) is “00000111.” FIG. 6B is a graph illustrating a second 8 sampling series taken over a 50 μsec period soon after the series of FIG. 6A, but with the IR LED on. Although the IR LED is on during the series of FIG. 6B, no hand (or other reflective object) is in proximity, and no (or virtually no) light from the IR LED is reflected into the PTR. Accordingly, the graph and sampling series bit sequence of FIG. 6B are substantially identical to FIG. 6A.
[0038] [0038]FIG. 7A is a graph reflecting a series of 8 voltage samples across the PTR taken over a 50 μsec period during a condition of high ambient light, with the IR LED off and with a hand nearby. Because a hand in proximity does not appreciably alter the ambient light level, the graph and sampling series bit sequence of FIG. 7A are substantially the same as those of FIG. 6A. FIG. 7B shows a graph illustrating a second 8 sample series taken over a 50 μsec period shortly after the series of FIG. 7A, but with the IR LED activated. In this case, light from the IR LED is reflected from a nearby hand into the PTR, causing a faster voltage rise rate and steeper voltage ramp. Unlike the series of FIG. 7A, where 5 samples were below V threshold , only the first 2 samples in FIG. 7B are below V threshold . The remaining 6 samples are above V threshold , resulting in a sampling series bit sequence (rotated LSB to MSB) of “00111111.”
[0039] As seen by comparing the example of FIG. 5B with the example of FIG. 6B, a bit sequence with a hand present in low ambient light can potentially be similar or identical to a bit sequence with no hand present in high ambient light. Without compensating for the ambient light level, a processor could not determine whether a hand-near condition existed. By comparing the IR LED off and IR LED on measurements, however, it is possible to compensate for the effect of ambient light. Proper spacing of the “on” and “off” sampling intervals prevents time varying ambient light (such as may occur with fluorescent lights, with incandescent light operating at 60 hz household current, etc.) from affecting operation of the invention. These time varying ambient light sources are slow compared to a 50 μsec sampling interval of one embodiment of the invention, so the effect on both the IR LED off measurement and the IR LED on measurement is effectively a constant amount which will be canceled when the two measurements are compared. As one example of system timing, each sampling cycle comprises a “LED off” series taken over a 50 μsec interval, separated by 200 μsec, followed by a “LED on” series taken over a 50 μsec interval. Sampling cycles are repeated at 50 millisecond intervals. This would result in microcontroller 51 being on for 100 μsec out of every 50,000 μsec (0.002), and the LED being on for 50 μsec out of every 50,000 μsec (0.001). The resultant power drain when the mouse is “asleep” is thereby much less than when “awake.”
[0040] Microcontroller 51 can also be configured to disregard spurious signals. If noise or other defect corrupts the signal received by microcontroller 51 , the resultant bit sequence will likely be a non-thermometer code. In other words, instead of any “1” bits being in a contiguous block (e.g., “00001111,” “00111111,” etc.), the bit series may have interleaved “0” and “1” bits (e.g., “00101011”). Microcontroller 51 can be configured to recognize such a series as invalid, and to disregard the results.
[0041] Another aspect of the invention allows a controllable amount of hysteresis, i.e., the system can wake up and go to sleep at different thresholds of illumination. This could be desirable for multiple reasons. A characteristic of LED-PTR pairs is that, as a reflective object approaches, the voltage across the PTR reaches a peak at a certain distance, and then decreases for further approach. Without differing wake and sleep thresholds, the voltage across the PTR could be lower when the user grasps a mouse than when the user's hand approaches, causing the mouse to resume sleep mode. To prevent this from occurring, microcontroller 51 is configured to wake the mouse at a first threshold, and to allow the mouse to sleep at a second threshold. As shown in FIG. 7A, a user's hand approaches the mouse in high ambient light. For the LED-off part of the sampling cycle, the sampling series bit sequence is 00000111. For the LED-on part of the cycle (FIG. 7B), the sampling series bit sequence is 00111111. Comparing these two sequences results in a 3 bit difference. Microcontroller 51 can be configured to recognize a difference of 3 or more 1-bits as a wake event, and thus microprocessor issues a wake signal. For this particular IR LED/PTR pair, however, reflection from objects closer than 1 cm could result in a voltage ramp decreased from what it might be for objects that are not as near. If, for example, a hand in contact with the mouse resulted in a sampling series bit sequence of 00011111, there may only be a 2 bit difference by comparison to an LED-off sequence, and the device would undesirably go to sleep. However, microcontroller 51 can be further configured so that, once in wake mode, it does not go to sleep until the bit difference between LED-off and LED-on is 1 bit or less.
[0042] One algorithm incorporating the invention is described in the flowcharts of FIGS. 8 - 12 . Although the example algorithm is described with reference to the PICBasic PrO™ language (available from microEngineering Labs, Inc. of Colorado Springs, Colo.) compiled for the Microchip PIC16F84-04/P microcontroller using the PICBasic Pro™ compiler (also available from microEngineering Labs, Inc.), persons skilled in the art will appreciate that this algorithm can be implemented in other hardware and software environments. Accordingly, the invention is not limited by the example provided.
[0043] As part of the exemplary algorithm, microcontroller 51 stores 0 if the voltage is below V threshold when measuring a PTR voltage ramp at port 52 or 53 . Microcontroller 51 stores a “1” bit if the voltage is equal to or above V threshold . The 1-bit samples of the PTR voltage ramp are stored in a 16-bit variable named Temp, with the bits rotated LSB to MSB. Referring again to the shallower curve of FIG. 3, where samples 1 - 5 are below V threshold and sample 6-8 are above V threshold , the 16-bit variable Temp would hold the binary sequence “0000000000000111”. With the microcontroller of the example circuit, only 8 samples will fit within a 50 μsec sampling interval. The sampling results are stored in a 16 bit register because the below-described PICBasic Pro™ language functions used to process the data require 16 bit arguments, in this case the register Temp. If the sampling bits were not rotated LSB to MSB, the resulting value of Temp would be “0000000011100000.” In other embodiments, a lesser or greater number of samples may be taken, and positions of the sampling values might not be rotated
[0044] Values of Temp with an IR LED off can be compared with values for Temp with the IR LED on in various ways. For example, the sampling series bit sequence from the LED-off interval can be exclusive-or (XOR) compared with the sequence from the LED-on interval. The result of such an XOR operation would be a bit sequence with the number of “1” bits equal to the difference between the two sequences. In the exemplary algorithm, the “ncd( )” encode function together with the “dcdo” decode function of the PICBasic PrO™ language are used to process the PTR ramp sampling sequence loaded in the input buffer Temp. The ncd( ) function returns a value equal to the highest order bit that is set to 1. For TEMP=0000000000000011, ncd(Temp)=3. In other environments, the ncd( ) function can be implemented as a function that returns 0 for arguments x equaling 0, and returning 1 plus the integer portion of log 2 (x) for all other values of x [i.e., int(log 2 (x))+1]. A variable B0 is then used to store the ncd(Temp) result.
[0045] A set of samples from a PTR ramp should yield a “thermometer code,” i.e., either all 0's or a series of 0's followed by a series of 1's, with no interleaved 0's and 1's. Sometimes, because of electrical noise or other problem, the PTR voltage might cross V threshold more than once during a single sample series. In one embodiment of this invention, a corrupted sequence could be detected. If the sequence is corrupted, it could be rejected. In the example, the dcd( ) decode function can be used. The dcd( ) function converts an argument, representing a bit number between 0 and 15, into a binary number with only the argument bit number set to “1.” For example, dcd(4) 0000000000010000 [2 4 =16 in decimal notation]. In other environments, the dcd( ) function could be implemented as a function returning 2× for an argument x. The dcd( ) function is then computed using the just-computed value of B0 as an argument. The combined result of dcd(B0) [i.e., dcd(ncd(Temp))] is a binary number having a decimal value of 2 N , where N is the highest order 1-bit in Temp. If the measured value of Temp is a block of 1-bits with the largest 1-bit equaling 2 (N−1) , adding 1 to Temp yields a binary number having a decimal value of 2 N . The following example illustrates this:
[0046] Temp=0000000000000111 [N=3, largest 1-bit=0000000000000100=2 N−1 ] ncd(Temp)=3
dcd ( ncd ( Temp ) ) = 0000000000001000 = 8 = 2 N Temp + 1 = 0000000000000111 + 1 = 0000000000001000 = 8 = 2 N = dcd ( ncd ( Temp ) )
[0047] Conversely, if any 0's corrupt the value of Temp (i.e., Temp is not a thermometer code), adding 1 to Temp will have a different result:
[0048] Temp=0000000000000101 [N=3, largest 1-bit=0000000000000100=2 N−1 ] ncd(Temp)=3
dcd ( ncd ( Temp ) ) = 0000000000001000 = 8 = 2 N Temp + 1 = 0000000000000101 + 1 = 0000000000000110 = 6 ≠ dcd ( ncd ( Temp ) )
[0049] Accordingly, in the exemplary embodiment, a test for a corrupted sequence can be implemented as a test for a non-zero result of dcd(ncd(Temp))−(Temp+1). If this test confirms a good (i.e., non-corrupt) sequence for Temp with the IR LED off, ncd(Temp) is stored in Temp off . Samples are then taken with the IR LED on and similarly tested.
[0050] After uncorrupted sequences are obtained with the IR LED off and with the IR LED on, the value of B0 with the IR LED on is compared to Temp off . Specifically, the difference between B0 (which represents the number of the highest bit set to “1” during an IR LED-on sampling) and Temp off (which represents the number of the highest bit set to “1” during an IR LED-off sampling) is calculated, and if the difference is above a designated level, a hand (or other object) is considered “near.” Using the high ambient light sampling series of FIGS. 7A & 7B as an example, B0=6 [int(log 2 (63))+1] and Temp off =3 [int(log 2 (7))+1]. If the “wake up” level is 3 or more, B0−Temp off =3, which is above the level and treated as a “hand-near” condition. Using the low ambient light sampling series of FIGS. 5A & 5B as an example, B0=3 [int(log 2 (7))+1] and Temp off =0[0]. Again, B0−Temp off =3, which is above the level and treated as a “hand-near” condition. By using Temp off as a reference point for comparison with an IR LED-on sampling series, and by resetting the reference point before each IR LED-on sampling, the level that will wake the device is adaptive to changing ambient light conditions, as well as to changing opto-electronic parameters caused by aging of a PTR/IR LED pair. Since the comparison is made using log 2 values of the readings, the threshold levels adjust as the reading with LED off moves up and down.
[0051] In addition to determining when a “far” to “near” change has occurred, a B0−Temp off difference can be used to determine whether the state of a proximity sensor has changed from “near” to “far.” Absent signal noise, malfunction or other abnormal condition, B0 (representing LED “on”) is always greater than or equal to Temp off (representing LED “off”). If B0 is greater than Temp off , then no change is made to the system, and a new measurement sequence is started. Moreover, the level for changing state can be made to depend on whether the reflective surface being sensed is approaching or moving away from the sensor. In the example, B0−Temp off must be greater than or equal to 3 counts for the sensor state to change from “far” to “near”. However, B0−Temp off must be less than or equal to 1 count for the sensor state to change from “near” to “far”.
[0052] Referring to FIG. 8, the exemplary algorithm according to one embodiment of the invention begins at start point 100 . Proceeding to step 110 , numerous variables are declared and initialized. Those variables and their purposes are described in Table 1.
TABLE 1 Variable Purpose Initial State B0 no. of “1” bits in sampled ramp 0 [=ncd(Temp)] B1 noise test variable 0 [=dcd(ncd(Temp)) − (Temp + 1)] Temp register for temporary storage of PTR ramp 0 measurements Temp off buffer for B0 with LED off 0 i loop counter 0 palmstate state of palm sensor 30 0 (far) [0 = far, 1 = near] sidestate state of side sensor 20 0 (far) [0 = far, 1 = near] position sensor in operation 0 (palm) [0 = palm, 1 = side] tail indicates if tail light on (and mouse “awake”) 0 (off) [0 = off/asleep, 1 = on/awake]
[0053] Proceeding to step 120 , microcontroller 51 pauses for approximately 48 msec in order to cause the total sampling time between a series of IR LED off and IR LED measurements to be approximately 50 msec. The duration of this pause can be varied. The total time between initiation of LED-off measurement and completion of LED-on measurement should be brief enough so that operation of the invention is imperceptible by comparison to human response time. At the other extreme, there should be sufficient pause between the LED-off and LED-on measurements to compensate for any latencies in the sensors or other system components. In the described example, one of the sensor pairs is active approximately every 50 msec. However, because the sensor pairs alternate, each individual sensor pair is only active approximately every 100 msec. The timing of the activation of the sensor pairs with respect to each other can be varied, trading faster total response time for additional power use (and thus shorter battery life).
[0054] Prior to sampling the PTR, LEDs 21 and 31 are turned off (by setting ports 55 and 56 to high), and PTRs 22 and 32 are “clamped” by grounding ports 52 and 53 . Ports 55 and 56 are further configured as output, and ports 52 and 53 are configured as input. At step 125 , Temp is again set to 0 prior to loading with sampling data bits. At step 130 , the algorithm branches based upon whether the side sensor 20 (position=1) or palm sensor 30 (position=0) is active. If position=0, PTR 32 (part of palm sensor 30 ) is read by microcontroller 51 with LED 31 off. Using a looping algorithm known to those skilled in the art, the first eight bit positions of Temp are loaded by sampling port 53 for successive increments of looping variable i:
[0055] for i=0 to 6
[0056] load LSB of Temp from port 53
[0057] left shift the contents of Temp by 1 bit
[0058] increment i by 1
[0059] For the eighth sample, the LSB of Temp is loaded from port 53 without rotation to the MSB. Because of the clock speed set by oscillator 61 , the LED-off sampling interval spans approximately 50 μsec. If instead position=1, PTR 22 (part of side sensor 20 ) is read by microcontroller 51 with LED 21 off. The same looping algorithm could be used, but with Temp instead loaded from port 52 .
[0060] After Temp is loaded, the PTRs are again clamped. At step 140 , the stored bit sequence is tested for noise. The formula described above can be used for this purpose:
[0061] B0=ncd(Temp)
[0062] B1=dcd(B0)−(Temp+1)
[0063] If B1≠0, there is noise or other problem with the sampling, the sample is discarded, and the program at step 150 returns to “passive” step 115 to begin again. If B1=0, then the sample is good (no noise), and B0 is stored as Temp off at step 160 . Microcontroller 51 then pauses again for approximately 300 μsec at step 165 , and at step 170 (“go to active”), the program proceeds to test the PTR with the LED on.
[0064] Referring to FIG. 9, the program proceeds from step 200 (“active”) to step 205 (“position?”). If position=0 (palm sensor 30 active), execution proceeds to step 210 , where LED 31 is activated, PTR 32 is clamped by grounding port 53 , port 56 is configured as output, and port 53 is configured as input. At step 212 , Temp is then set to 0, and at step 214 the first 8 bits of Temp are loaded using the same algorithm set forth above. If instead position=1 (side sensor 20 active), execution proceeds to step 220 , where LED 21 is activated, PTR 22 is clamped by grounding port 52 , port 55 is configured as output, and port 52 is configured as input. At step 222 , Temp is then set to 0, and at step 224 the first 8 bits of Temp are loaded using the same algorithm set forth above. At step 230 , the activated LED is turned off. At step 235 , Temp is again tested for noise using the formula described above. If B1≠0, the sampling series is rejected, and at step 237 the program returns to “passive” step 115 (FIG. 8). If B1=0, the sampling result is again tested at step 240 by comparing Temp off (which represents the ramp sampling with the LED off) to B0 (which now represents the ramp sampling with the LED on). Because B0 should always be equal to or greater than Temp off , the sampling is rejected if Temp off >B0, and the program returns at step 245 to “passive” step 115 . If Temp off is not greater than B0, the program proceeds to step 250 .
[0065] At step 250 , the sampling results with the LED on and off are compared by setting Temp equal to the difference between B0 and Temp off . If position=0 (palm sensor active), the program proceeds from step 252 (“position?”) to step 254 (“A”) to step 300 (FIG. 10). Referring to FIG. 10, execution proceeds from step 300 to decision step 310 (“current state=near or far?”). If palmstate=0, the palm sensor 30 was last set to a “far” condition. The program then proceeds to step 320 (“Temp<3”). If Temp (now set to the difference between the LED-off and LED-on sampling sequences) is less than the activation level of 3, there is no change in state (i.e., a hand or other object is not near palm sensor 30 ), and the program proceeds at step 340 to “restart” (step 540 , FIG. 12). If, however, Temp is at or above the activation level of 3, Temp is not less than 3, indicating there is a change in state (i.e., a hand or other object is near palm sensor 30 ). Execution proceeds to step 350 and the state is changed. If at step 310 palmstate=1, the palm sensor 30 was last set to a “near” condition. The program would then proceed to step 330 (“Temp>1”). Because the deactivation level requires that the difference between LED-off and LED-on sampling be less than or equal to 1, there is no change in state unless Temp is not greater than 1. If Temp>1, the program proceeds at step 340 to “restart” (step 540 , FIG. 12). Otherwise, a change in state has occurred (i.e., a hand or other object is no longer near), and the state is changed at step 350 .
[0066] If, after step 250 (FIG. 9), position=1 (side sensor active), the program would have instead proceeded from step 252 (“position?”) to step 256 (“B”) to step 400 (FIG. 11). As shown in FIG. 11, however, the steps followed if the side sensor is active are similar to those of FIG. 10. “Palm sensor active” steps 300 , 310 , 320 , 330 , 340 , 350 and 355 are respectively analogous to “side sensor active” steps 400 , 410 , 420 , 430 , 440 , 450 and 455 .
[0067] If the state of palm sensor 30 is changed at step 350 (or the state of side sensor 20 is changed at step 450 ), the program proceeds from point 500 to decision point 510 (FIG. 12). If both palm and side sensors are in a “near” state (palmstate=1 and sidestate=1), execution proceeds to step 530 . The mouse is “awake,” the tail light 40 is illuminated (or left illuminated if already on), and other mouse circuitry is activated (or left on). If both sensors are not in a near state (either or both palmstate and sidestate=0), execution proceeds to step 520 . The tail light 40 is not activated (or is deactivated if active), and the mouse is “asleep” (or put to sleep if previously awake). After either condition, the program then proceeds through “restart” point 540 to step 550 , where the active sensor changes from palm to side (position=0 to position=1) or from side to palm (position=1 to position=0), and the program returns to “passive” step 115 (FIG. 8) to commence again.
[0068] During each cycle of the embodiment described above, the program samples and compares either the side or the palm sensor in LED-off and LED-on conditions. Although the program of this embodiment completes two cycles before the mouse wakes or goes to sleep, the time is still short by comparison to human response time, and therefore imperceptible to a user.
[0069] Although a single example of carrying out the invention has been described, those skilled in the art will appreciate that there are numerous variations and permutations of the above described system and technique that fall within the spirit and scope of the invention as set forth in the appended claims. As but one example, the values chosen for activation and deactivation thresholds, as well as other criteria within the above-described algorithm, can be varied. As another example, comparing PTR readings with the LED off and PTR readings with the LED on need not be based on determining the difference in readings above V threshold ; the invention also embraces determining the difference in readings below a threshold. Similarly, the invention also embraces comparing readings by subtracting a larger number (e.g., the number of “1” bits representing samples above V threshold with an LED on) from a smaller number (the number of “1” bits with the LED off), resulting in a negative number, and using another negative number as the “wake-up” level. Multiple hardware variations are also possible. As but one example, a single LED could be used with two PTRs, and energy from the LED transmitted to the vicinity of the PTRs by fiber optic connections or other wave guides. Instead of a microcontroller or microprocessor as described above, the invention could be implemented on other types of processors or hardware platforms capable of automatically carrying out the sampling and comparison features described. As but one example, the invention could be implemented using a state machine of an Application Specific Integrated Circuit (ASIC). These and other modifications are within the scope of the invention, which is only to be limited by the attached claims. | A proximity sensor measures receptor output with an energy source deactivated. The sensor then measures receptor output with the energy source activated. The measurements with the energy source activated are compared to the measurements with the energy source deactivated to compensate for the effect of ambient conditions. A near condition is recognized if the change between the two groups of measurements exceeds a designated value. To compensate for receptor output that may decrease after reaching a peak value during approach of an object, a near condition can be maintained until the change between the two groups of measurements no longer exceeds a different designated value. Multiple sensors can be used to avoid false near conditions caused by, e.g., placing a device equipped with the sensors next to a stationary object. In one embodiment, a sensor comprises an infrared light emitting diode and a phototransistor. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of prior U.S. application Ser. No. 12/783,035, filed May 19, 2010.
TECHNICAL FIELD
The apparatus disclosed herein relates to a mirror mount such as mirror mount that mounts a mirror to the fender of a vehicle.
BACKGROUND
Mirrors mounted on fenders of vehicles such as buses and trucks are well known. These mirrors are typically mounted using a plurality of mirror support arms that form a mounting frame in which some of the arms in the frame are fastened to the fender of the vehicle and some of the arms in the frame are fastened to the mirror.
It is also known to mount a mirror to the fender of a vehicle using a base member that is clamped to the vehicle at the fender. The base member is generally in the shape of an L that wraps around or hugs the exterior of the fender. A bracket has a first end that is fastened such as by screws or bolts to the upper portion of the base member and a second end that extends under the hood of the vehicle to clamp the upper portion of the base member to the vehicle. Straps clamp the lower portion of the base member to the vehicle such as by use of the wheel well.
As is obvious, the second end of the bracket can be bolted or screwed to the vehicle frame under the hood in order to add strength to this mount. It is also known to bolt or screw the lower portion of the base member to the fender.
These mounting arrangements lack sufficient stiffness for a rugged and stable mirror mount. They also lack strength and do not add to fender stability and driver visibility.
The present invention overcomes one or more of these or other problems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a mirror mount that mounts a mirror to a fender of a vehicle;
FIG. 2 is an isometric view of a base member of the mirror mount of FIG. 1 ;
FIG. 3 is another isometric view of the base member of FIG. 2 ;
FIG. 4 is a back view of the base member of FIG. 2 ;
FIG. 5 is a front view of the base member of FIG. 2 ;
FIG. 6 is a bottom view of the base member of FIG. 2 ;
FIG. 7 is still another isometric view of the base member of FIG. 2 ;
FIG. 8 is an isometric view showing the base member attached to a fender;
FIG. 9 is cut away view showing the attachment of the base member to a fender;
FIG. 10 illustrates an exploded view pivot assembly that mounts the mirror arm to the pivot support; and,
FIG. 11 illustrates a cross section of the assembled pivot assembly.
DETAILED DESCRIPTION
As shown in FIG. 1 , a mirror mount 10 includes a base member 12 that mounts a mirror 14 to the fender 16 of a vehicle 18 . A mirror support arm 20 has one of its ends suitably fastened to the mirror 14 and another of its ends pivotally attached to the base member 12 by way of a pivot 22 .
As shown in FIGS. 2-9 , the base member 12 has an interior contour 24 that generally follows the profile of the fender 16 to hug the fender 16 when the base member 12 is applied to the vehicle 18 . The base member 12 has an end 26 that extends into the compartment of the vehicle 18 under a hood 28 of the vehicle 18 between the hood 28 and the fender 16 . The end 26 has holes 30 and 32 to receive fasteners such as screws or bolts to fasten the end 26 to the vehicle 18 as more fully explained below. Thus, when the base member is affixed to the fender 16 , the end 26 extends generally in a downward, vertical direction and the holes 30 and 32 are generally horizontal.
The base member 12 has a further end 34 that extends down alongside the exterior of the fender 16 . The end 34 has holes 36 and 38 to receive fasteners such as screws or bolts to fasten the end 34 to the fender 16 of the vehicle 18 .
The base member 12 has a top portion 40 that rests on the top of the fender 16 and that is integrally formed with the end 26 . The base member 12 includes ribs 42 that are formed between the end 26 and the top portion 40 . The ribs 42 are reinforcing ribs that improve the stiffness of the mirror mount 10 over the known mirror mounts described above. The ribs 42 are integrally formed with top portion 40 and the end 26 .
The base member 12 also has a side portion 44 that extends along the exterior of the fender 16 in a downward direction and generally closely profiles the exterior contour of the fender 16 . The side portion 44 is integrally formed with the end 34 and the top portion 40 .
The base member 12 includes a pivot support 46 that supports the pivot 22 attaching the mirror support arm 20 to the base member 12 .
The pivot support 46 is integrally formed with the other portions of the base member 12 described herein so that the base member 12 is molecularly continuous. For example, the base member 12 may be a one-piece cast member.
The base member 12 has a neck 48 near the pivot support 46 . The pivot 22 is suitably affixed to the pivot support 46 and pivots within the curvature of the neck 48 so that the mirror 14 can be pivoted between a viewing position as shown in FIG. 1 where the mirror 14 provides a rear facing view and a retracted position.
As shown in FIG. 9 , the end 26 of the base member 12 extends between the fender 16 and the hood 28 and partially into the engine compartment of the vehicle 18 . Screws or bolts 50 and 52 extend through the holes 30 and 32 in order to affix the end 26 of the base member 12 to the fender 16 . Also, screws or bolts 54 and 56 extend through the holes 36 and 38 in order to affix the end 34 of the base member 12 to the fender 16 .
As shown in FIG. 9 , the fender 16 includes a generally horizontal portion 58 that is suitably screwed or bolted to a frame 60 of the vehicle 18 under the hood 28 , a generally vertical portion 62 that extends alongside the hood 28 from the generally horizontal portion 58 , and a curved exterior portion 64 . The screw or bolt 50 is screwed or bolted through the generally vertical portion 62 , through the curved exterior portion 64 , and into a column 66 formed as an integral part of the base member 12 . Although not shown, the screw or bolt 52 is similarly screwed or bolted through the generally vertical portion 62 , through the curved exterior portion 64 , and into a column 68 formed as an integral part of the base member 12 . Thus, the screws or bolts 50 and 52 extend through the holes 30 and 32 , through the two portions 62 and 64 of the fender, and into the columns 66 and 68 of the side portion 44 in order to affix the end 26 of the base member 12 to the fender 16 .
In this manner, the base member 12 at the end 26 is clamped to the fender 16 . This cross bolt feature provided by the screws or bolts 50 and 52 traps the fender 16 against the contour 24 of the base member 12 to strengthen and stabilize the fender 16 at the top portion of the base member 12 . The one piece base member 12 closely profiles the fender 16 . The reinforcing ribs 42 improves the stiffness of the base member 12 over current two piece designs to provide a rugged and stable mirror mount. The combination of the cross bolt feature and the one piece design of the base member 12 provide improved fender stability and, therefore, improved mirror stability and driver visibility over current two piece designs.
A pivot post 80 is assembled into a base 82 of the pivot support 46 . The pivot post 80 includes a post 84 , and a downwardly directed face 86 , and an upwardly directed face 88 . The downwardly directed face 86 and the base 82 include aligning serrated teeth. The serrated teeth of the downwardly directed face 86 and the base 82 align in a pre-determined orientation. This pre-determined orientation sets the pivot post 80 in its home position location and prevents rotation of the pivot post 80 when cycling with the mating of these teeth serrations. This pre-determined home position places the mirror support arm 20 and the mirror 14 in the proper viewing position. The serration teeth in both the pivot post 80 and the base 82 , for example, may be equally spaced, such as every 6 degrees which would allow adjustment in 6 degree increments of the home position, if required.
The bottom of the pivot 22 and the upwardly directed face 88 include ramps that mate when the pivot 22 is placed over the post 84 of the pivot post 80 , the mating ramps aligning for proper assembly position.
A wear washer 90 and a tension spring 92 are placed inside the pivot 22 so that the wear washer 90 and the tension spring 92 are placed concentrically over the post 84 of the pivot post 80 . A coating of lubricating grease may be applied between the mating ramps of the bottom of the pivot 22 and the upwardly directed face 88 and may be applied at both ends of the tension spring 92 prior to assembly to minimize cycle rotation wear.
A pivot cap 94 is then placed on top of the tension spring 92 such that a pivot bolt 96 extends through the pivot support 46 and the pivot base 80 and is threaded into the pivot cap 94 , which is tightened down on the pivot bolt 96 to an internal stop feature within a pre-determined torque range. This action compresses the tension spring 92 to produce proper force between the mating ramps of the pivot post 80 and the pivot 22 .
Accordingly, the mirror support arm 20 and the mirror 14 can be rotated from the home position to the most forward or rearward positions, causing the ramps of the pivot 22 and the upwardly directed face 88 of the pivot post 80 to ride out and separate. When the mirror support arm 20 and the mirror 14 are rotated back to the original viewing position, the mirror support arm 20 will snap back into its original ramp alignment and home position.
Modifications of the present invention will occur to those practicing in the art of the present invention. Accordingly, the description of the present invention is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the appended claims is reserved. | A mirror mount that mounts a mirror to a fender of a vehicle includes a base member having a first end generally vertical when the base member is affixed to a fender and arranged to receive a fastener passing through the first end, through the fender, and into the base member so as to fasten the base member to the fender, a second end, a side portion extending between the first end and the second end and having a contour that follows an exterior profile of the fender, and a reinforcement reinforcing the first end. | 1 |
BACKGROUND OF THE INVENTION
Printed German Application No. 1,753,695, U.S. Pat. No. 3,399,425, and British Patent No. 1,072,236 disclose processes and apparatus for manufacturing products which have a tufted surface from non-fibrous polymers. In these known processes at least one thermoplastic layer is pressed to the extent of at least part of its thickness against a heatable surface, which is provided with projections or depressions and the layer is subsequently stripped from the surface. In one of the processes, the surface of the polymer layer which has been shaped by the pressing operation is heated to a moderately elevated temperature as it is stripped.
German Patent Specification No. 1,266,441, corresponding to U.S. Pat. No. 3,708,565 describes another process in which a polymer is brought between two smooth drawing surfaces and in a molten state is torn apart at right angles to its direction of movement and is cooled at the same time so that fibers are formed. In that case the coolant stream acts on the fiber-forming region in a direction which is opposite to the direction of movement of the polymer. In a more recent process, which is a development of the one just outlined and has been disclosed in the Opened German Application No. 2,053,408, the molten polymer is forced through a porous carrier and against a smooth drawing surface, from which the layer is then pulled and simultaneously cooled so that fibers are formed.
Opened German Specification No. 2,157,510 describes a process of manufacturing a product which has a plush surface. That process is characterized in that, inter alia, the polymer is forced with the aid of a carrier against a heatable drawing surface and, as the formation of the fibers begins, is pulled away from said drawing surface with simultaneous cooling and subsequent deflection of the carrier. The coolant stream acts also into the fiber-forming region in a direction which is opposite to the direction of travel of the carrier. Besides, a contact cooling is effected on the rear of the carrier. Processes of this kind have the disadvantage that the fibers which are forming are contacted by the coolant throughout their length at the same time, so that the action of the coolant on fibers behind those which are being formed is highly reduced; this is not altered by the contact cooling on the rear.
A development of that proposal in consideration of its disadvantages has led to a process which is disclosed in Opened German Specification No. 2,057,149, corresponding to U.S. Pat. No. 3,701,621 and in which a flowing coolant acts on the rear of the carrier approximately in the direction of travel of the carrier and flows along and in part through the carrier. In that case the carrier layer is not deflected in the fiber-forming region and fibers which are forming remain subjected to the temperature of the heated drawing surface.
In these known processes, cooling is accomplished by a stream of gas or liquid, which produces a cooling action which is either too slow or too abrupt. In connection with such processes, it is generally stated that the polymer must be completely removed from the drawing surface to avoid interference with subsequent fiber formation.
The recognition of the shortcomings have led to providing means which control the action of the flowing fluid in the very area in which the fibers originate or are in "statu nascendi" and also control of the shape of the fibers throughout the fiber-forming region so that production can be carried out at a high, economical rate and the quality of the product can be uniformly controlled.
SUMMARY OF THE INVENTION
The necessary control of the flowing fluid is accomplished by a process which, according to the invention, is characterized in that the fluid flows through a carrier serving as a drawing surface for the polymer and then enters the fiber-forming region. The carrier is withdrawn and, within the region which is subjected to the action of the flowing fluid, the carrier together with the adhered polymer is deflected from its direction so as to move away from the other drawing surface. By regulating the temperature of the drawing surface with respect to the surroundings, the temperature of the polymer and, also by regulating the input polymer-volume depending from or to the volume of flowing coolant a continuous coating is produced which stays on the drawing surface in a thickness of at least 10 microns. The molten polymer is supplied to the fiber-forming region at a temperature which is above, and preferably considerably above, its melting point; i.e., at a temperature of 10°-200° C above the melting point.
DETAILED DESCRIPTION
It is of significance for the process that, in the region subjected to the action of the flowing fluid, the carrier surface is separated from the heatable drawing surface and is deflected when a spacing between the surfaces of 0.5-40 millimeters, preferably between 0.5 and 10 millimeters, has been established. The distance travelled by the carrier prior to deflection depends on the curvature of the heatable drawing surface. Within the scope of the invention, the distance travelled may amount to between a few millimeters and some centimeters, preferably between 5 and 50 millimeters and up to an upper limit of about 100 millimeters. As a result of the deflection of the carrier, the root portion of the fiber is withdrawn from the intense action of the flowing fluid so that this portion is extended to a smaller thickness and a longitudinal molecular orientation is imparted to the fibers before the tips of the fibers are torn from the heated drawing surface near their upper ends.
It has been found necessary to provide for a proportionality or approximately proportionality between the solidification rate of the polymer and of the fibers' temperature. Thus, if the solidification is too rapid, the molten polymer is torn apart only as coarse fibers so that flakes rather than the desired fibers would be formed from molten material of high viscosity, whereas only thin filaments having bulblike roots could be pulled from molten polycondensates of low viscosity.
For this reason, the process of the invention is applied primarily to polymerization products which have a low molecular weight and, correspondingly, a high melt index.
On the other hand, the use of highly crystalline high polymers, particularly of polycondensates of such polymers, is rendered difficult by the high crystallization rate. It has thus proved desirable to use such high polymers in the form of copolymers or in polyblends together with other polymers so that the tendency to crystallize is reduced and the solidification range is increased. For instance, pure polyoxymethylene (POM) when used alone results in thin and brittle fibers but, in admixture with 10% by weight low density polyethylene, it can be used to produce a useful product having a catskinlike feel or hand. An admixture of polyamides with POM also improves the fiber-forming process. On the other hand, pure Polyamide 6 (PA 6) when used alone results in thin fibers which look like cotton-wool. If this material is copolymerized with Polyamide 66 (PA 66) or with ethylene or is mixed with 12% by weight polymethylmethacrylate of low viscosity, a fabric-like textile plush can be produced. Mixtures of Polyamide 6 (PA 6) with Polyamide 11 (PA 11) or PA 12 or PA 6.10 exhibit a wider solidification range; in these cases, the second component may be added in an amount up to 30% by weight. Other mixtures which have given favorable results comprise saturated polyesters, such as polyethyleneterephthalate or polybutyleneterephthalate, together with Polyamide 6, PA 11, PA 12 or copolyamides. The fiber-forming process and the quality of the product can be improved if such polyblends are additionally cross-lined as they are processed.
The use of pure polypropylene (PP) having an MFI at 190/5 of 20 normally results in a fiber having a thickness of, e.g., 10 microns. The addition of Polyamide 12 results in increasingly thinner fibers until the proportion of PA 12 is so large that a structure like that of cotton-wool is obtained.
Inorganic substances, such as fillers and dyestuffs or additives have a high thermal conductivity, when used in the polymer layer accelerate solidification during the formation of fibers. In most cases, such fibers tear off sooner. In the process according to the invention, the use of such substances in a concentration up to 50% by weight is facilitated by the use of polymers having a low melt viscosity. Polymers which in a molten state have a low viscosity have proved particularly suitable for use in processes according to the invention.
These include, inter alia:
polyethylene having a MFI 190/2 of 10-300 grams/10 minutes;
ethylene/vinyl acetate having a MFI 190/2 above 10 grams/10 minutes;
polypropylene having a MFI 190/5 of 10-70 grams/10 minutes;
polymethylmethacrylate having a MFI 210/10 above 10 grams/10 minutes;
cellulose acetate, cellulose acetate/butyrate, and cellulose propionate CA, CAB, CP having a MFI 190/2 above 8;
polyoxymethylene having a MFI 190/2 above 13 grams/10 minutes;
polyvinyl chloride/acetate having a K value below 50;
hard polyvinylchloride having a K value below 60 and containing at least 15% plasticizer;
polyamide 6 having a relative velocity between 2.1 and 3.4;
polyamide 12 having a relative viscosity between 1.7 and 21.1; and
polyethyleneterephthalate having a relative viscosity above 1.6.
It is apparent from the above data that additional polymerization products are useful in the new process if they have a high melt index, whereas polycondensates such as polyamides and saturated polyesters can be used in commercially available grades.
The following considerations, inter alia, govern the selection of polymers:
A low melt viscosity improves the adhesion so that much more fiber nuclei are formed than in case of a high melt viscosity;
A molten material at a high temperature results in a lower melt viscosity so that the fiber-drawing time is prolonged, and this prolongation provides for a longer time in which measures to control the process can be carried into effect.
It is necessary according to the invention that only a part of the polymer is converted into fibers in the fiber-forming region. In conventional processes it has always been attempted to ensure that the heatable drawing surface is free of residual polymer after the fiber-forming operation is completed because it was feared that the next pass resulting from the continued movement of the heatable drawing surface would otherwise disturb the fiber-forming process. Results obtained using the process according to the invention have proved opposite. The fiber-forming process of the invention is carried out in such a manner that the forces of cohesion in the polymer cause the solidifying fibers to visibly constrict near their point of contact with the heatable drawing surface rather than at said point and to be torn apart clearly at a distance from the drawing surface. Thus, in accordance with the invention a substantially continuous polymer coating produced on the heatable drawing surface in the first fiber-forming process is intentionally maintained in a thickness of at least 10 micron after this first fiber-forming process and additional polymer is coated on the first coating as the movement of the drawing surface is continued. From the endpoints of the torn fibers, which are located within infinitesimal distances from one another, the coating surface structure becomes a mountain and valley-like shape when leaving the fiber forming region. The smallest thickness of the coating is at least 10 microns in the valley portion. During the transport by the heated drawing surface the coating then becomes smoother and smoother due to the surface tension, so that it reaches the point of input of new polymer in even a flat condition. If desired, the additional polymer may be admixed during the formation of fibers with the retained polymer film or layer so that the layer is continually renewed.
The admixing of a new polymer layer of a dissimilar polymer with polymer coating remaining on the drawing surface can be used to transform layers of dissimilar polymers in the fiber-forming process into composite fibers by an action which is the same as that during the formation of the fibers from a single layer. Fibers of polyblends differ from fibers made from a single layer in that the different polymers are laminated rather than finely dispersed therein. This feature permits of a production of fibers having properties which cannot be obtained from a mixture of polymers having different melt viscosities.
Laminated fibers can also be produced, e.g., by a fibrillation of layers of polyvinylchloride and a second polymer. In this case, the process can be controlled so that each fiber contains layers of pure polyvinylchloride which are adjoined, possibly with gradual transitions, by other layers which consist only of the other polymer. Because this lamination results in fibers having specific properties, such a fiber structure can be predetermined in view of the desired fiber properties such that the finished fiber has the combination of properties which are optimally required for a given use.
In connection with certain fiber properties it is significant that, in the region in which the carrier is deflected, the flowing fluid is applied at an angle within the range of +65° to -45° , preferably of +55° to -15° , relative to a normal plane of the heatable drawing surface in the deflecting region. Thus the flowing fluid does not impinge with maximum intensity on the area where the fiber nuclei are formed but must flow through the carrier in that region in which the polymer layer is distorted and transformed into fibers. The flow of the fluid is then diverted at the heatable drawing surface so that the fluid is deflected partly into the region where the fiber nuclei are formed and partly into the fiber-forming region in which the fibers solidify completely. Such action can be controlled by a selection of the direction of flow of the approaching fluid. The form of the fibers is greatly dependent on the intensity of the action of the flowing fluid.
The flowing fluid consists of gases, vapors, sprayed liquids, or of solids entrained by gases and/or vapors, or of mixtures thereof. Mixtures of gases and liquids have proved particularly satisfactory with the process of the invention because they result in a particularly large heat transfer and can take up much heat. The use of gas-liquid mixtures is also preferred because the evaporation of the liquid results in a cooling of the fluid. The use of mixtures of gases and liquids and of a substance which can react with the liquid or gas to extract heat therefrom has also proved desirable and practicable. The chemical substance may be used in solid or liquid form. An action which can be matched with solidification in a simple manner can be obtained by the use of a sprayed liquid at moderately elevated temperatures. Besides, mixtures may be used as coolants in such a manner that at least one component of the mixture is deposited on the fibers.
An important feature of the process of the invention resides in that the carrier is deflected by at least 5° and at most 90° from its direction, preferably, as explained below, in a range of 10°-80°. The degree of deflection of the carrier is chosen mainly in consideration of the nature of the polymer and of the desired quality. Where mainly linear polymers are used, a larger angle of deflection is preferred than with branched polymers. Optimum results are to be expected if, in the processing of polyolefins (other than low density polyethlene), the angles of deflection lie between 30° and 80° whereas in the processing of low density polyethylene they should lie in a range between 10° and 60° . In the processing of saturated linear polyesters, the selected angles lie in the range from 50° to 80° , and in the processing of cellulose acetate, cellulose acetate butyrate the selected range is between 20° and 60°. Polyblends can be processed with good results if the angle of deflection is at least 80°.
If longer fibers are to be produced from the polymers listed hereinabove, angles of deflection near the upper limits stated are preferred.
It has been found desirable to protect unfibrillated polymer, i.e., the coating or polymeric film on the drawing surface from the action of the atmosphere, e.g., by a suitable covering, which may suitably consist of non-oxidizing gases. By using such measures, oxidation which would disturb the process can be inhibited. Whereas these disturbances are not measurably important with respect to the quality of the fibers, they may result in a discontinuity in the application of the polymer to, and the uniformity of contact with, the heatable drawing surface. With some polymers, such as commercially available polyolefins, an antioxidant incorporated in the polymer layer can accomplish this result. In other polymers, primarily polycondensates, the action of such antioxidant is insufficient so that it is necessary to prevent directly access of oxygen. For instance, it has been found to be preferable particularly in the processing of polyoxymethylene, polycarbonates, polyamides, and saturated polyesters to provide a shield or to use a non-oxidizing gas which flows around the polymer layers. In such case, a shield is provided which is spaced about 5-10 millimeters from the heatable drawing surface and parallel thereto and which protects the drawing surface from the environment and also acts as a reflector. Whereas it is known that polyamide can be processed only with difficulty, it can be uniformly fibrillated when this measure is adopted. If the remaining unfibrillated polymer is contacted by flowing non-oxidizing gas, the thermal decomposition of the polymer will be reduced. This is favorable with respect to the strength of the fiber as well as in subsequent processing, such as the dyeing of polyamide and polyester fibers.
The above described process is carried out with suitable apparatus which is characterized in that a nozzle body is desposed adjacent to the fiber-forming region and in contact with the carrier at the point of deflection of the carrier.
The deflection of the carrier in the area of the discharge orifice of the fluid is generally accomplished by the nozzle body and for this purpose that portion of the nozzle body which surrounds the discharge orifice is suitably formed as a comb which is rounded or tapers to a sharp edge and has teeth which are connected or disconnected at their distal ends. The carrier may alternatively be deflected just before or just behind the discharge orifice although the tolerance should possibly not be in excess of 10 millimeters.
Further details and advantages of the process and the design of apparatus for carrying out the process will now be explained with reference to embodiments shown in the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic general view showing an apparatus for carrying out the process.
FIG. 2 is an enlarged view showing a detail of FIG. 1 and
FIG. 3 shows a modification of FIG. 1.
The apparatus shown in FIG. 1 comprises a driven drum 10 which forms one of the drawing surfaces and is heatable by a heater 11 and a conduit 12. A nozzle body 14 is disposed near the surface of the drum 10 and is mounted in a holder 13 to be pivotally movable and adapted to be displaced toward the surface of the drum. The nozzle body has a slotlike discharge orifice 15 which extends throughout the length of the drum and can be arranged to face the drum 10 in all angular positions of the nozzle body. The nozzle body 14 is connected by a conduit to a fluid pressure generator 16. A mixture fitting 17 may be connected, which can be operated by hand or which can be operated automatically to work dependently with process variables.
Feed means (not shown) are provided for applying to the surface of the drum 10 a polymer layer 18 and a carrier web 19 for the polymer. The carrier web wraps the drum 10 in a part of its surface. The apparatus extending across the length of the drum is so designed that after the fiber-forming operation (which will be described more fully hereinafter) a residual polymer film 20 is left on the drum surface and carrier 19 is deflected around the nozzle body 14 by an angle 30. The angle of deflection 30 is measured from a tangential plane 32, which is applied to a generatrix 31 of the drum surface. At generatrix 31, polymer 18 and carrier 19 begin to separate from the cylindrical surface which is formed by the surface of the drum.
That portion of the drum surface, which in the direction of rotation (arrow 33) succeeds the point of deflection and which is disposed between said point and the point where additional polymer 18 is applied, is surrounded by a shield 21. The space between the surface of the drum and shield 21 is filled by a non-oxidizing gas, which is supplied through a fitting 22.
The nozzle body 14 provided with the fluid discharge orifice 15 can be adjusted within a wide range for an unrestricted adaptation to all process variables. It is also apparent that, in the illustrated embodiment, holder 13 is pivotally movable within an angular range of about ±75° relative to an imaginary radial plane 34 which intersects the nozzle discharge orifice and about the line where plane 34 intersects the surface of drum 10. The distance 24 of the discharge orifice 15 from the surface of drum 10 can be adjusted and fixed within a range of 0.5-40 millimeters.
As is apparent from FIG. 1, polymer 18 is applied in a radial plane intermediate the surface of drum 10 and carrier 19 in the direction of movement of the drum 10 as indicated by the arrow 33. Alternatively, the lines of application of the polymer and carrier may lie in one and the same radial plane.
FIG. 2 is an enlarged view showing a portion of FIG. 1 to illustrate details of the arrangement near the point of deflection. FIG. 2 illustrates how fibers are formed in fiber-forming region 25 which, in the direction of movement of the drum 10, is disposed between the generatrix 31, the fibrillation region and carrier 19. In the embodiment of FIG. 2 the nozzle body 14 is positioned at positive angle 27 with respect to radial plane 34.
At the intersection of the radial plane 34 and the heated drum 10 polymer 18 has been raised to such a temperature that it is 10°-200° above the melting point so that it adheres on one side to carrier 19 and on the other side to drawing surface 23. Because the carrier begins to separate from drawing surface portion 23 of the surface of the drum 10 before reaching plane 34, the film-like molten polymer 18 begins to separate from the drawing surface 23 and adheres on the upper surface of the carrier. This separation proceeds transversely to the tangential plane 32 as the separation of the carrier 19 from the drawing surface 23 increases. The free spaces formed on both sides of the polymer 18 as the result of the separation of webs 36 merge to form cavities 39 as the separation of carrier 19 from drawing surface 23 increases; these cavities are disposed in the interior of the polymer and extend transversely to the plane of the drawing. This action takes place adjacent to orifice slot 15 of nozzle body 14. For this reason, the action of the discharging fluid and the intentional deflection of the nozzle body begin here. The nozzle body comprises a comb which extends at right angles to the plane of the drawing throughout the length of the drum 10. As a result of this incipient action, the webs 36 of polymer between the elongated cavities 37 are progressively attenuated so that constrictions 39 are formed which progressively increase in a peripheral direction to such an extent that the tensile forces which are produced in the polymer as a result of the increasing separation overcome the cohesive forces. As a result, polymer filaments are formed, which are distributed over the length of the drum and are transformed into solidified, stabilized and fibers having a longitudinal orientation. Controlling variables, such as the rate at which the polymer is supplied per unit of time, the circumferential velocity of the drum 10, the drum's surface temperature, the surrounding temperature and the polymer's temperature, pressures and consequently the velocity and volume of flow of the fluid, the input of polymer and the structural dimensions of the apparatus, are adjusted so that the polymer is not completely transformed into fibers but a film 20 of residual polymer is intentionally provided because the maintenance of such film has been found to be essential for and characteristic of the process. Some of these variables are naturally regulated depending to the drum's surface qualities or adhesion qualities therefrom.
As is apparent from the transverse sectional view of the nozzle body 14, the latter contains a flow-dividing grid 26 which insures that the fluid discharged from the orifice slot 15 forms individual streams which are uniformly distributed over the cross-section of the slot. These streams insure uniform fiber-forming conditions throughout the length of the drum 10 particularly because said streams flow at uniform velocities.
In nozzle body 14, the comb may form a sharp edge so that the point of deflection 41 and the discharge orifice of the nozzle are accommodated within a very small space. In other cases, a certain distance between the discharge orifice and the point of deflection may be more desirable. In still other cases, the polymer layer must be deflected on a generatrix of the drum surface before the discharge orifice of the nozzle body 14, when viewed in the direction of rotation of the drum 10.
FIG. 3 shows an apparatus which is provided with a heatable belt 50, which is trained around the drum 10' and forms the drawing surface 23' for the polymer 18' and the carrier 19'. The carrier 19' is again deflected in the fiber-forming region 25' about a nozzle body 14'. This embodiment has the advantage of requiring less space.
The fiber-forming process is inevitably accompanied by flow processes by which the film produced on the surface of the drum 10 and consisting of polymer which has not been used to form fibers receives a coating of additional polymer or additional polymers. Because the polymer layers are molten, they mix but without a dispersion such as would result from the mixing of the polymer by a stirrer. A laminated mixture results and is subjected to the process of the invention so that laminated fibers are formed which have a longitudinal orientation.
The drawing surfaces must be designed so as to ensure a good adhesion of the polymer to the drawing surface. For the sake of economy, drawing surfaces are provided which consist of portions of preferably cylindrical bodies because such bodies can be made at very low cost by lathe operations. This concept has been adopted in the embodiments explained hereinbefore. All surface-finishing processes which are known in the art may be used unless they result in surfaces to which the polymer cannot adhere or can only poorly adhere. The drawing surfaces may be chromium-plated, polished, or lapped, for instance. The same criteria are applicable to belts such as are shown in FIG. 3 of the drawing. Drawing surfaces consist suitably of metallic surfaces although the invention is not restricted thereto. Metallic drawing surfaces can easily be machined and provide for a particularly good and uniform conduction of heat.
All techniques known in the art may be adopted to heat surfaces which are used according to the invention. Heat may be supplied by conduction, conversion or radiation.
As regards the design of the nozzle body, it has already been pointed out that it should suitably be capable of a pivotal, rotational or translational movement so that it can be moved to a position which is an optimum in view of specific requirements. The drag which is due to the carrier and the fiber-forming region may be used to deflect at least part of the flowing fluid so that it flows opposite to the direction of movement of the carrier and if desired, substantially parallel to the carrier. For this purpose, the nozzle body may be provided with bevelled or rounded surfaces (reference numeral 41).
Besides, numerous ways are known in fluid dynamics to control a fluid so that it can perform the functions which are required. As stated above the fluid may generally consist of gases or vapors, or of liquid or solid particles entrained by a flowing fluid and such liquid and/or solid particles may be added to the fluid before it enters the nozzle body. A simple measure comprises the spraying of water into flowing air. In this case, the points of supply may be disposed before or in the discharge orifice of the nozzle body or between the latter and the carrier and/or polymer. Such points of supply may be disposed at different locations. Where the fluid consists of a gas, an inert gas is preferred and may consist mainly of nitrogen and carbon dioxide.
The state of the fluid is of significance and may be adjusted in any known manner by pressure, temperature, ionization and/or other electric or electrostatic or electrodynamic or magnetic and electromagnetic charges and other variables which control state to ensure the desired behavior. Certain limits must be taken into account which define the ranges in which the required intermediate values and such limits will mainly depend on the required fiber properties. For instance, if the action exerted by the fluid to promote the formation of fibers is insufficient, the formation of fibers will also be insufficient and the production will lack economy. On the other hand, if the intensity of the action is increased beyond a certain limit, the molten polymer will solidify too rapidly and the formation of fibers will be insufficient for this reason. It has also been found that the molecular orientation of the fibers will depend on the angle of deflection and on the distance of the deflecting means from the drawing surface. As these are empirical values, the accompanying table gives a synopsis of the order of magnitude of the values in question so that an interpolation may be used to indicate (also for polyblends) the values which will result in fibers having predetermined properties.
TABLE__________________________________________________________________________Part A Drum Nozzle Polymer Amount Carrier Amount temp. Orifice angleNo. Type g/m.sup.2 Type g/m.sup.2 ° C mm deg.__________________________________________________________________________1 PVCA.sup.3 80 PU.sup.1 60 205 4 4 K = 50 foam 30 kg/m.sup.32 PVCA.sup.3 80 VSF.sup.2 60 205 2.5 6 K = 50 woven fabric 20/133 PP.sup.4 60 PU.sup.1 60 190 4 10 MFI foam = 60 30 kg/m.sup.34 " 100 " " " 12 75 " 90 VSF.sup.2 60 " 3 10 woven fabric 20/136 LD-PE.sup.5 90 " " 205 1.7 5 MFI = 207 " 300 " " 205 15 108 PMMA.sup.6 90 " " 235 3 12 MFI = 129 POM.sup.7 100 " " 195 2.5 1010 PA 6.sup.8 90 " " 245 2 4 rel. visc = 2.811 PA 6.sup.8 90 " " 245 2 4 + 15% PMMA.sup.612 Mix- 90 " " 205 1.7 5 ture 50% LD-PE.sup.5 50% talcum13 1st 70 " " 205 2 10 layer PVCA.sup.3 2nd 50 layer LD-PE.sup.5__________________________________________________________________________ .sup.1 PU = polyurethane .sup.2 VSF = viscose staple fiber .sup.3 PCVA = polyvinyl chloride/acetate .sup.4 PP = polypropylene .sup.5 LD-PE = low density polyethyle .sup.6 PMMA = polymethylmethacrylate .sup.7 POM = polyoxymethylene .sup.8 PA = polyamidePart B Angle of Air Velocity Length deflection pressure of carrier of FibersNo. deg. mm water m/min mm__________________________________________________________________________1 40 300 1.5 102 40 600 1.8 113 60 700 3 124 70 450 3 455 60 700 4 126 40 1,500 5 37 70 1,500 2 308 50 1,300 4 129 50 1,200 3.5 1210 70 700 6 1211 70 700 6 1212 40 1,500 5 413 60 1,200 4 7__________________________________________________________________________ | A process is provided for manufacturing a product which has a fibrous surface and is formed by the conversion of a non-fibrous polymer, which process comprises placing a polymer between drawing surfaces which adjoin the polymer and adhere thereto and separating the surfaces. At least one of the surfaces is formed by a carrier for the polymer and for the fibers, through which carrier a fluid is blown such as to flow around the fibers in statu nascendi and orient and stabilize them as their viscosity increases. An apparatus for carrying out said process is also provided. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a color display tube having an in-line electron gun equipped with a field controller, and in particular to a color display tube optimum to a color monitor display device of high resolution in which the electron beam is deflected with a horizontal scanning frequency higher than the standard horizontal scanning frequency.
In a color cathode-ray tube having an in-line electron gun, three electron beams are arranged on a line in a coplane. Therefore, two exterior beams among the in-line beams are eccentric with respect to the electro-magnetic deflection center. The electron beam passing through the convergence electrode is deflected by the leakage magnetic field originating from the deflection yoke. At this time, the magnetic flux of the leakage magnetic field is not uniform over the section of the electron gun. Accordingly, the amount of deflection (deflection sensitivity) of the center beam is different from that of the exterior beams. As a result, the shape of the raster formed by the scanning of the center beam (green) is different from that formed by the scanning of each of the exterior beams (red and blue). The so-called coma aberration is generated, resulting in poor color reproduction at comparatively exterior parts on the screen.
In order to compensate the coma aberration, a field controller for controlling the magnetic flux distribution of the leakage magnetic flux at the rear end side of the deflection yoke is disposed in a region through which the electron beam passes. This field controller is made of a magnetic material having high permeability.
A color display tube having such a field controller is disclosed in Japanese Examined Patent Publication No. 26208/76 assigned to the Tokyo Shibaura Electric Industrial Company and filed May 18, 1971, for example.
In the standard color television system, 15.75 kHz is generally used as the horizontal scanning frequency f H . In recent years, higher resolution is demanded for the picture on the display monitor device of the computer terminal. Therefore, a higher frequency as compared with the standard system tends to be chosen as the horizontal scanning frequency. As a result, coma distortion is caused. In particular, especially large distortion is caused on the left side of the screen, resulting in a problem.
The present inventors took note of this phenomenon and conducted experiments. As a result, the present inventors found that a higher deflection field frequency deteriorates the magnetic characteristics of the field controller and hence the desired compensation function for the leakage magnetic field is lost, resulting in the above described problem. That is to say, the increase in the deflection magnetic field frequency (horizontal scanning frequency) causes an increase in eddy-current loss of the field controller. Thus the permeability of the field controller is lowered and hence the effect of the magnetic shield or the magnetic enhancement is deteriorated. When the horizontal scanning frequency is raised in the case of the field controller functioning the magnetic shield, the deflection amount of the center beam becomes small and the deflection amount of the exterior beam becomes large. In the case of the field controller functioning the magnetic enhancement the contrary becomes true. Further, an increase in the horizontal scanning frequency shortens the horizontal . retrace line time. Due to the magnetic aftereffect, the amount of misconvergence between the center beam and the exterior beams becomes large especially on the left side of the screen.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a color display tube wherein the magnetism deterioration of the field controller caused by using a higher frequency as the horizontal deflection frequency is reduced and the degradation in convergence grade is prevented.
In order to achieve the above described object, the color display tube according to the present invention includes a field controller comprising a material having high permeability and low coercive force.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an electron gun for illustrating an embodiment of a color cathode-ray tube according to the present invention;
FIG. 2 is a plane view of a convergence electrode of FIG. 1 seen from the fluorescent screen side;
FIGS. 3 and 4 are magnetic field diagrams of an electromagnetic deflection yoke of an in-line color display tube;
FIG. 5 is a convergence pattern diagram;
FIGS. 6 and 7 are graphs showing convergence characteristics of a conventional field controller when different horizontal scanning frequencies are used;
FIG. 8 is a graph for comparing convergence characteristics of a field controller according to the present invention with those of a conventional field controller; and
FIGS. 9 and 10 are plane views of other embodiments of the present invention seen from the fluorescent screen side of the convergence electrode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will now be described by referring to drawings.
FIG. 1 is a sectional view of a principal part of an in-line electron gun for illustrating an embodiment of a color display tube with an envelope 20 and a deflection yoke 21 according to the present invention. In FIG. 1, cathodes 1A, 1B and 1C emitting respective one of three electron beams from respective vertex planes, the first grid 2 for controlling the electron beam, the second grid 3 for accelerating the electron beam, and a lower part 4 of the third grid for focusing the electron beam are illustrated. Numerals 2A, 2B, 2C, 3A, 3B, 3C, 4A, 4B and 4C denote holes for passing three electron beams. Numerals 5 and 6 denote an upper part of the third grid and the fourth grid respectively. In conjunction with three diaphragm holes 5A, 5B and 5C disposed on the bottom of the upper part 5 of the third grid, three diaphragm holes 6A, 6B and 6C disposed on the bottom of the fourth grid 6 so as to be opposed to the diaphragm holes 5A, 5B and 5C constitute three main lenses corresponding to three electron beams. A convergence electrode 7 is fixedly disposed on the opening end side of the fourth grid 6. The convergence electrode 7 has holes 7A, 7B and 7C for passing three electron beams. The plane view of the convergence electrode 7 is shown in FIG. 2. The first field controllers 8a and 8b taking the shape of a ring are fixedly disposed on the peripheries of the exterior beam passing holes 7A and 7C, respectively. The second field controllers 9a and 9b taking the shape of a thin disc are fixedly disposed above and below the center beam passing hole 7B. For the field controllers 8a, 8b, 9a and 9b, a material having small hysteresis loss, eddy-current loss and magnetic aftereffect and having fine magnetic characteristics at high frequencies is chosen.
Results of the experiment for choosing the material will be described later. The experimental results obtained by the present inventors indicate that 78% Ni--Cu--Mo system permalloy is desirable as the material of the field controller. The field controllers 8a, 8b, 9a and 9b are obtained by pressing a plate of the above described material and annealing the plate.
In FIG. 2, broken lines represent the leakage magnetic field coming from the horizontal deflection yoke. The first field controllers 8a and 8b serve as the field with respect to the leakage magnetic field, while the second field controllers 9a and 9b function to concentrate the magnetic flux. In the vicinity of the center electron beam passing hole 7B, the magnetic flux density becomes high. In the vicinity of the exterior electron beam passing holes 7A and 7C, the magnetic flux density becomes coarse.
In this configuration, the electron beam amounts of the three electron beams A, B and C are controlled by means of signal voltage values applied to three cathodes 1A, 1B and 1C, respectively. The three electron beams A, B and C then undergo somewhat focusing function in prefocus lenses formed between opposing holes of the second grid 3 and the lower part 4 of the third grid. Thereafter the three electron beams A, B and C are focused to form an image on a fluorescent screen of the cathode-ray tube, which is not illustrated, by respective main lenses formed by the upper part 5 of the third grid and the fourth grid 6. The beam passing holes 6A and 6C of the fourth grid 6 are slightly eccentric toward the outside with respect to the beam passing holes 5A and 5C of the upper part 5 of the third grid. This eccentricity supplies the exterior beams A and C with inclination of angle θ toward the center beam B. Three electron beams A, B and C pass through beam passing holes 7A, 7B and 7C of the convergence electrode 7. In addition, the exterior beams A and C pass through the field controllers 8a and 8b. The color cathode-ray tube has deflection coils at its funnel portion. By making the magnetic field produced by the vertical deflection coil barrel-shaped as shown in FIG. 3 and making the magnetic field produced by the horizontal deflection coil pincushion-shaped as shown in FIG. 4, it is possible to focus three electron beams passing through the convergence electrode 7 correctly onto one position on the fluorescent screen. In FIGS. 3 and 4, numerals 10 and 11 denote vertical deflection magnetic field and horizontal deflection magnetic field.
FIG. 5 shows a misconvergence (coma aberration) state in which rasters obtained by scanning of respective beams do not agree each other due to the use of the horizontal scanning frequency higher than the standard value. As described before, an increase in horizontal scanning frequency degrades the magnetic characteristics of the field controller as compared with the initial state, resulting in deteriorated characteristics of the magnetic substance. Therefore, the difference between amounts of deflection of electron beams caused by the nonuniform distribution of the leakage deflection magnetic field comes to the front. As a result, a raster 14 produced by the center electron beam (green) and represented by solid lines does not agree with rasters 12 and 13 produced by the exterior electron beams (red and blue) and represented by broken lines. The amount δ of misconvergence (i.e., the amount of deflection deficiency of the center beam B with respect to the exterior beams A and C) becomes significant as the horizontal deflection frequency is raised.
FIGS. 6 and 7 are graphs for comparing the amount δof misconvergence measured when the horizontal scanning frequency f H is a standard value, i.e., 15.75 kHz with that measured when the horizontal scanning frequency f H is raised to 21.83 kHz. Measurement was made under the condition that the field controller was made of a conventional magnetic substance comprising 45% Ni. FIG. 6 shows the convergence characteristics on the left side of the screen, while FIG. 7 shows the convergence characteristics on the right side of the screen. In both figures, the ordinate represents the deviation δ of the raster 14 produced by the center beam from the rasters 12 and 13 produced by the exterior beams. The symbol - indicates that the raster 14 exists outside the rasters 12 and 13, while the symbol + indicates that the raster 14 exists inside the rasters 12 and 13. The abscissa of FIG. 6 represents the back porch (μs) which is a time period ranging from the falling point of the horizontal synchronization signal to the starting point of the video signal. The abscissa of FIG. 7 represents the front porch (μs) which is a time period ranging from the end point of the video signal to the rising point of the horizontal synchronizing signal. It is to be noted that the time periods of the back porch and the front porch become shorter as the horizontal scanning frequency is raised in both figures. Assuming that the abscissa of FIG. 6 is replaced by the horizontal position on the screen, the video signal starting point indicated by an arrow may be substantially regarded as the starting point (left end) of the raster. It is apparent from FIG. 6 that at both frequencies the transition phenomenon degrades the magnetic characteristics of the field controller and hence increases the misconvergence δ at the portion where the horizontal synchronizing signal is switched to the horizontal scanning signal which is lower than the horizontal synchronizing signal. This is the magnetic aftereffect phenomenon. Further, it is understood that the amount of misconvergence δ is entirely increased due to an increase in eddy-current loss of the magnetic substance when the horizontal scanning frequency f H is raised from the standard value of 15.75 kHz to 21.83 kHz. When the horizontal scanning frequency f H is 15.75 kHz, there is little misconvergence δ because the back porch is long and the left end of the raster is sufficiently apart from the portion where the misconvergence is generated (the portion of the magnetic aftereffect). When the horizontal scanning frequency f H is chosen to be 21.83 kHz, however, the back porch becomes short and the left end of the raster moves to the left side of FIG. 6. Therefore, the vicinity of the left side of the raster is completely affected by the magnetic aftereffect, the misconvergence being not negligible. FIG. 7 shows the amount of misconvergence appearing on the right side of the screen and is almost free from the magnetic aftereffect. Even if the horizontal scanning frequency is changed, the amount of misconvergence is permissible.
FIG. 8 shows the misconvergence characteristics of the field controller using the material according to the present invention as compared with the misconvergence characteristics of the field controller using a conventional material. A plot of FIG. 8 comprising triangular marks represents the misconvergence characteristics appearing on the left side of the screen obtained when the field controller made of a conventional magnetic material containing 45% Ni is used with the horizontal scanning frequency f H =21.83 kHz. A plot of FIG. 8 comprising white dots represents the misconvergence characteristics appearing on the left side of the screen obtained when a field controller made of 78% Ni--Cu--Mo system permalloy according to the present invention is used with the horizontal scanning frequency f H =21.83 kHz. A plot of FIG. 8 comprising black dots represents the misconvergence characteristics appearing on the left side of the screen obtained when the same field controller according to the present invention is used with the horizontal scanning frequency f H =15.75 kHz (standard value). As is evident from FIG. 8, the magnetic aftereffect is reduced in the field controller according to the present invention. Even at the left end of the raster, the amount δ of misconvergence is approximately -0.2 mm and well in the permissible range.
In the embodiment of the present invention, 78% Ni--Cu--Mo system permalloy was used. This was chosen as the material satisfying the magnetic characteristics condition imposed upon the field controller, i.e., the condition that the permeability is 3,000 H/m (Henry/meter) or more and the coercive force is 0.025 Oe (Oersted) or less. So far as the condition is satisfied, any material other than 78% Ni--Cu--Mo system permalloy may be used. The permeability value of the magnetic material can be generally increased by increasing the content ratio of Ni. Depending upon the value of the content ratio, however, the volume resistivity associated with the coercive force might become small, resulting in an increased eddy-current loss. The permeability was defined to be 3,000 H/m or more so as to sufficiently compensate the misconvergence by the shield or enhancement effect of the leakage magnetic field during the period of FIG. 8 free from the magnetic aftereffect, i.e., during the static deflection field period. Further, the coercive force affects the eddy-current loss in alternating current magnetic field. Therefore, the decrease in permeability caused by the eddy-current loss in the high frequency magnetic field can be constrained by making the coercive force small as far as possible. The coercive force was defined to be 0.025 Oe or less so as to sufficiently reduce the eddy-current and let the amount of misconvergence due to the magnetic aftereffect fall in the permissible range.
In the above described embodiment, the first field controllers 8a and 8b are disposed on the peripheries of the exterior beam passing holes 7A and 7C, and the second field controllers 9a and 9b are disposed above and below the center beam passing hole 7B. However, the present invention is not limited thereto. Even if only the first field controllers 8a and 8b are disposed on the peripheries of the exterior beam passing holes 7A and 7C as shown in FIG. 9 or only the second field controllers 9a and 9b are arranged above and below the center beam passing hole 7B as shown in FIG. 10, for example, a similar effect can be obtained more or less. | There is provided a color display tube having an in-line electron gun for emitting a plurality of electron beams comprising a convergence device for converging the plurality of electron beams emitted from the electron gun onto a predetermined point by using a magnetic field, a deflection device for deflecting the electron beams converged by said convergence device by using a deflection magnetic field, and a field controller disposed between the convergence device and the deflection device in order to adjust the distribution of leakage magnetic field from the deflection device so as to make the leakage magnetic field exert influence upon respective electron beams uniformly, the field controller comprising a magnetic material having relative permeability of 3,000 H/m or more and coercive force of 0.025 Oe or less. | 7 |
[0001] This application claims priority from U.S. Provisional Application No. 60/408,022, filed Sep. 4, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to the production of polyolefin-based adhesive resins, and particularly to an improved process for producing polyolefin-based adhesive resins.
BACKGROUND OF THE INVENTION
[0003] Conventional polyolefin-based adhesive resins for bonding to or bonding together polyolefins and polar materials such as nylon, ethylene vinyl alcohol copolymer, metals and the like, are made using multiple step processes. First, an olefin, such as ethylene, commonly in gaseous form, is polymerized or co-polymerized with other monomers to form a polyolefin and extruded into pellets as a finished form.
[0004] Second, at least some polyolefin thus prepared must be further chemically reacted with a chemical having a polar functional group to provide a modified (“grafted”) polyolefin having a polar functionality (herein referred to as a “graft”). One way of performing this step is to visbreak the polyolefin in the molten state under conditions of high shear and/or temperature, in the presence of the polar monomer, to cause formation of free radicals that then react with the polar monomer. Another way is to dissolve the polyolefin in a solvent along with the polar monomer in the presence of a peroxide catalyst or other suitable catalyst that facilitates chemical grafting of the monomer onto the polyolefin in solution. Either process results in a polyolefin grafted with a polar monomer. The graft copolymer thus prepared is then typically pelletized in an extruder.
[0005] Third, the graft copolymer is typically melt-blended with an additional quantity of polyolefin to dilute the graft copolymer to a desired concentration, and to provide a polyolefin-based adhesive resin that has processing and physical properties suitable for the end use application. The mixing is usually performed by melting the polyolefin pellets and the graft pellets above the melting point of the two components and mixing the melted materials to desirably obtain a homogenous product. This additional melt blending is yet another expense. The polyolefin-based adhesive resin thus prepared is then pelletized from an extruder.
[0006] There is a need for a less expensive, less complicated process for producing polyolefin-based adhesive resins. There is also a need for a better quality polyolefin-based adhesive resin.
[0007] An example of a process for producing polyolefin-based adhesive resin is described in U.S. Pat. No. 4,478,885, issued Dec. 11, 1984. The process described therein utilizes a major amount of polyolefin polymer or polymers, which, as described above, has been formed by polymerizing an olefin or olefins and extruded into pellets as a finished form. The pelletized polymer or polymers are next mixed with graft and heated to above the melting point of the components under high shear. A heated extruder may be used to accomplish the latter step, and the melt mixed product can be recovered in the form of pellets. As noted in the patent, the product of the process may consist of from about 70-99.5 wt. % of polyolefin, e.g. polyethylene, and about 0.05-30 wt. % of the graft.
[0008] While conventional processes for producing polyolefin-based adhesive resins have been found to be useful, there are several disadvantages inherent in those processes. For example, in heating and shearing the polymerized polyolefin, e.g. polyethylene, usually in the form of pellets, above its melting point, imperfections, usually in the form of gelled polymer, are formed with each such heat history. The least amount of such imperfections is desired so that the adhesive resin when applied to a substrate will be continuous and without visible and/or functional imperfections.
[0009] Additionally, the conventional processes described above are costly due to the additional equipment and the energy required to first polymerize the olefin monomer, pelletize the polyolefin, and then melt and mix the formed polyolefin and graft material to form the adhesive product.
[0010] Thus there is a need for an improved process for producing polyolefin-based adhesive resins which reduces the amount of imperfections, such as gelled polymer, of the polyolefin material by eliminating one melt processing and extrusion step after the polymerization. There is also a need for a process that reduces the time, energy and equipment required to produce the desired polyolefin-based adhesive resins.
SUMMARY OF THE INVENTION
[0011] One object of the present invention is to provide an improved process for producing polyolefin-based adhesive resins.
[0012] Another object of this invention is to provide a process for producing polyolefin-based adhesive resins that reduces the amount of imperfections in the produced adhesive resin.
[0013] Another object of this invention is to provide a process for producing polyolefin-based adhesive resins that improves properties, such as optical properties in thin films of the produced adhesive resin as compared to polyolefin-based adhesive resins produced by heretofore conventional processes.
[0014] Still another object of this invention is to provide an improved process for producing polyolefin-based adhesive resin that reduces the time, energy and equipment required to produce the adhesives as compared to conventional processes for such production.
[0015] These and other objects and advantages of the present invention will be apparent from the following description.
[0016] As explained above, in heretofore known processes the polyolefin that is graft polymerized to form a polyolefin-based adhesive resin is exposed to at least two, and often three, melt extrusion and pelletizing steps before it can be sold for commercial use. Additional polyolefin used in the resin is exposed to two melt extrusion and pelletizing steps, once following synthesis of the polyolefin and once while mixing the polyolefin with the graft copolymer. The present invention is directed to a process that eliminates at least one of the melt processing and extrusion steps for the polyolefin-based adhesive resin, and to an improved polyolefin-based adhesive resin thus prepared.
[0017] In accordance with the present invention, a process is provided that advantageously eliminates the need for reheating and melting of polyolefin polymer and reduces imperfections due to such reheating and melting of polymer, in producing polyolefin-based adhesive resins. The term “polyolefin” is defined as including homopolymers and copolymers of olefin monomers having from 2-12 carbon atoms. Examples of suitable polyolefins include without limitation high density polyethylene (linear ethylene polymers having a density of at least 0.945 grams/cm 3 ), branched low density polyethylene (branched ethylene polymers having a density of about 0.900 to about 0.944 grams/cm 3 ), linear low density polyethylene (linear ethylene-alpha olefin copolymers having a density of about 0.870 to about 0.944 grams/cm 3 and including a C 3 to C 12 alpha-olefin comonomer), polypropylene homopolymers, propylene-ethylene copolymers, butene-1 homopolymers and copolymers, and the like. The term “polyolefin” also includes copolymers of olefins such as ethylene with vinyl acetate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, acrylic acid, methacrylic acid, acid terpolymers and the like, which contain at least 50% by weight ethylene.
[0018] The process comprises polymerizing an olefin, mixture of olefins or mixture of olefins and other monomers, where preferably the olefin or olefins have from about 2 to 8 carbon atoms, for example by polymerizing at least one olefin monomer mixture using a conventional reactor process, and mixing the polymerization product with a graft and either with or without another component, such as an adhesion promoting resin, preferably elastomer, and more preferably a thermoplastic elastomer, or a metallocene catalyzed polyolefin, in a heated extruder or other heated mixing device at a temperature above the melting point of the components to obtain the desired grafted polyolefin-based adhesive resin.
[0019] The process may be utilized to produce adhesives based on any olefin to produce corresponding polyolefin-based adhesive resins of such polyolefins, for example, high density polyethylene (HDPE), polypropylene, and the like, and copolymerizations in a single or more than one polymerization reactors, in series or in parallel. In the case of polyethylene as a polyolefin, the olefin monomers include ethylene and less than 50% of one or more other monomers, which may include alkenes, for example, propylene, butene-1, hexene-1,4-methyl pentene-1, octene-1, and other unsaturated aliphatic hydrocarbons; also, ethylenically unsaturated esters, such as vinyl acetate, methyl acrylate, ethyl acrylate and butyl acrylate.
[0020] “Graft” as heretofore defined is understood to include any of the functional polymeric compositions or other structures as described in U.S. Pat. Nos. 3,658,948; 3,697,465; 3,862,265; 3,868,433; 4,087,587; 4,087,588; 4,487,885; 5,070,143 and others.
[0021] In accordance with the invention, a polyolefin is synthesized by a conventional process. The polyolefin from the reactor is fed to a mixing device, such as a mixing extruder, where it is combined with a graft copolymer in pellet or powder form that has been separately produced, prior to pelletizing to form a polyolefin-based adhesive resin. The graft copolymer can be the reaction product of a thermoplastic polymer and a polar monomer, and may be produced according to a known technique. As described, the polyolefin is melt blended with the graft copolymer in a mixing device, preferably a mixing extruder, to yield a polyolefin-based adhesive resin. The adhesive resin is discharged from the mixing device, preferably a mixing extruder, through a die having multiple openings, and is cooled and pelletized.
[0022] The process of the invention reduces the number of melt extrusion and pelletizing steps for the ungrafted polyolefin portion of the adhesive from two to one. The only melt extrusion and pelletizing seen by the polyolefin occurs in the reactor's existing in-line mixing device after synthesis of the polyolefin, after it is blended with the graft copolymer. This reduction in melt mixing and melt extrusion history is significant because the polyolefin (excluding the graft copolymer) often constitutes 80-99% of the polyolefin-based adhesive resin.
[0023] Polyolefin-based adhesive resins produced according to the invention have less degradation, less crosslinking and better (whiter) color than conventional polyolefin-based adhesive resins having more extensive heat histories. Films produced using the improved polyolefin-based adhesive resin, tend to have better optical properties, including increased clarity, less haze and/or less gels. The polyolefin-based adhesive resin of the invention is also less expensive to manufacture.
[0024] The polyolefin-based, grafted copolymer adhesive resin obtained by the process of the present invention is particularly useful in a variety of applications, particularly for bonding to materials or bonding materials together, for example such materials as polyolefins, polyamides, polyvinyl alcohol, ethylene vinyl alcohol copolymer, metals, glass, wood and/or paper, and other substrates, particularly polar substrates; and in fabrication processes, such as powder coating, rotational molding, film-forming processes using standard cast film and blown film extrusion and coextrusion processes; application to multiple substrates using thermal lamination, extrusion lamination, and extrusion and coextrusion processes including blow molding, sheet extrusion, and pipe.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] In a preferred embodiment, the process of the present invention is desirably performed by polymerizing ethylene with other olefin monomers according to known polymerization techniques, and mixing the raw product of the polymerization with a graft as heretofore described. The olefin monomer mixture may have the composition of primarily ethylene with less than 50% of other alkenes as heretofore described.
[0026] In accordance with a particular embodiment of this invention, the polyolefin is fed to a mixing extruder immediately following synthesis. A graft copolymer that has been separately manufactured, is added to the same mixing extruder and is blended with the polyolefin prior to pelletizing. The graft copolymer may be based on the same or different polyolefin as the synthesized polyolefin, and is desirably based on a similar polyolefin. The graft copolymer may also be based on a thermoplastic elastomer, such as an ABA block copolymer having polystyrene end blocks and an olefin or diolefin midblock. Such elastomers are described in U.S. Pat. No. 5,070,143, the disclosure of which is incorporated by reference. The resulting graft polyolefin-based adhesive resin is then extruded through a die having multiple openings and is cooled and pelletized.
[0027] The polyolefin-based adhesive resin produced according to the embodiment may include from about 0.05 to about 30% by weight of the graft copolymer, preferably from about 1 to about 20% by weight of the graft copolymer, and most preferably from about 2 to about 15% by weight of the graft copolymer. Additional adhesion-promoting resins, such as thermoplastic elastomers, may also be added and blended with the polyolefin and graft copolymer at this stage. When used, the thermoplastic elastomer may constitute from about 1 to about 30% by weight of the polyolefin-based adhesive resin. The balance of the polyolefin-based adhesive resin is substantially the polyolefin that was just synthesized. The polyolefin may constitute from about 50 to about 99.9% by weight of the polyolefin-based adhesive, preferably from about 70 to about 99% by weight, and most preferably from about 85 to about 98% by weight.
[0028] The graft copolymer is a copolymer of a polyolefin or thermoplastic elastomer as described above, and a polar comonomer. The term “polar comonomer” refers to organic molecules (e.g. monomers) having a carboxyl, hydroxyl, anhydride or other oxygen functionality. When grafted onto polyolefins and/or thermoplastic elastomers, these monomers exhibit polar attraction to, and under certain conditions may chemically react with, polar surfaces of polyolefins, polyamides, polyvinyl alcohol, ethylene vinyl alcohol copolymer, metals, glass, wood and/or paper and other substrates. Suitable polar monomers include without limitation carboxylic and dicarboxylic acids and their anhydrides, for instance maleic acid, fumaric acid, maleic anhydride; 4-methylcyclohex-4-ene-1,2 dicarboxylic acid and its anydride; tetrahydrophthalic acid and its anhydride; x-methylnorborn-5-ene-2,3 dicarboxylic acid and its anhydride; norborn-5-ene-2,3 dicarboxylic acid and its anhydride; maleo-pimaric acid and its anhydride; bicyclo(2.2.2) oct-5-ene-2,3-dicarboxylic acid and its anhydride; 1, 2, 3, 4, 5, 8, 9, 10-octahydronaphthalene-2,3-dicarboxylic acid and its anhydride; 2-oxa-1,3,-diketospiro (4.4)non-7-ene, bicyclo(2.2.1)hept-5-ene-2,3-dicarboxylic acid and its anhydride; nadic anhydride, methyl nadic anhydride, himic anhydride, and methyl himic anhydride. Other suitable polar monomers are described in U.S. Pat. Nos. 3,873,643 and 3,882,914, the disclosures of which are incorporated by reference.
[0029] In the embodiment of the invention described above, the graft copolymer can be produced using a conventional process. Conventional grafting processes include without limitation a) processes where the polyolefin or thermoplastic elastomer is reacted with the polar comonomer in the presence of sufficient heat and shear to visbreak the molten polymer and form free radicals which react with the monomer, b) processes where the molten polyolefin or thermoplastic elastomer is reacted with the polar monomer in the presence of heat and a catalyst, such as a peroxide catalyst, and c) processes where the polyolefin or thermoplastic elastomer is reacted with the polar monomer in a suitable solvent, in the presence of a catalyst. An exemplary process for preparing a graft copolymer is described in U.S. Pat. No. 4,087,587, the disclosure of which is incorporated by reference. The graft copolymer may include from about 85 to about 99.999% by weight of the base polymer and from about 0.001 to about 15% by weight of the grafted polar monomer, preferably from about 95 to about 99.99% by weight of the polyolefin and from about 0.01 to about 5% by weight of the grafted polar monomer; preferably from about 97 to about 99.9% by weight of the polyolefin and from about 0.1 to about 3% by weight of the grafted polar monomer.
EXAMPLE
[0030] In this example, ethylene and butene gases were introduced into the polymerization reactor of a commercial large-scale polyethylene manufacturing system. The mixture was polymerized in the reactor using a suitable Zeigler-Natta catalyst, forming an ethylene-butene copolymer, commonly referred to as linear low density polyethylene (LLDPE). The LLDPE polymerization product with a density of 0.918 g/cc was then discharged from the reactor in the form of a powder and fed into an accumulator bin in line with the reactor, and then was combined with graft as the LLDPE was transported into a continuous mixer. The graft was a high density polyethylene grafted with maleic anhydride. Maleic anhydride content, based on combined weight of the polymers, was 0.2%. The LLDPE powder and the graft copolymer were heated to a temperature of approximately 400-450 degrees F. and subjected to shear mixing. Following mixing, the mixture was pelletized as it exited the mixer. Six-185,000 pound lots of pelletized polyolefin-based adhesive resin were thus produced by the process of the present invention. This experiment was performed by Equistar Chemicals, LP using a large-scale polyethylene manufacturing facility (480 million pounds per year capacity).
COMPARATIVE EXAMPLE
[0031] For comparative purposes, LLDPE, which had been previously manufactured in the reactor and pelletized, was mixed with the same graft copolymer as noted above in the same proportions, in a continuous mixer heated to a temperature of approximately 400-450 degrees F. and subjected to shear mixing. The mixture was pelletized as it exited the mixer. This pelletized product is utilized as the CONTROL in the following tests.
Test 1
[0032] To determine the amount of undesirable gelled polymer in the adhesive product, pellets of adhesive produced above in accordance with the present invention, referred to as Lots 1-6, and pellets of CONTROL produced as described above, were separately introduced into a single screw extruder, and extruded into a blown 3 mil monolayer film. The amount of gelled polymer in the films of Lots 1-6 and of the CONTROL were determined by counting the number of gelled polymer or gels in a given area of the film and normalizing the count for a 50 square foot area by a laser gel scanner. The following counts were found:
Gel Count Lot 1 2582 Lot 2 2360 Lot 3 2499 Lot 4 2206 Lot 5 1930 Lot 6 2177 Lots 1-6 2292 (averaged) CONTROL 3423
[0033] Thus, TEST 1 shows the desired reduction in the amount of imperfections due to gelled polymer in polyolefin-based adhesive resin produced in accordance with the present invention as compared to the amount of imperfections due to gelled polymer of polyolefin-based adhesive resin produced under the heretofore known conventional processes.
[0034] The optical properties of films prepared as in TEST 1 were evaluated as noted in the following tests:
Test II
[0035] Haze, i.e., the clarity of films, in this case of films of 2 mil thickness prepared as noted above, was determined in accordance with ASTM Test No. D-1003, as follows:
Haze % Lot 1 7.8 Lot 2 7.4 Lot 3 7.5 Lot 4 7.8 Lot 5 7.6 Lot 6 7.6 Lots 1-6 7.6 (averaged) CONTROL 10.2
Test III
[0036] The gloss of 2 mil films as noted above was determined in accordance with ASTM Test No. D-2457, with the following results:
Gloss Units Lot 1 68.8 Lot 2 69.8 Lot 3 70.5 Lot 4 67.9 Lot 5 70.0 Lot 6 69.1 Lots 1-6 69.4 (averaged) CONTROL 62.7
Test IV
[0037] Transparency of 2 mil films as noted above was determined in accordance with ASTM Test No. D1746, as narrow angle scatter (“NAS”) as follows:
NAS, % Lot 1 71.9 Lot 2 72.5 Lot 3 72.4 Lot 4 73.1 Lot 5 75.1 Lot 6 73.8 Lots 1-6 73.1 (averaged) CONTROL 66
Test V
[0038] Degradation of polyolefin-based adhesive resin produced in accordance with the present invention as compared to that of polyolefin-based adhesive resin produced in accordance with heretofore known processes was demonstrated by measuring the yellowness of 2 mil films prepared as noted above in accordance with ASTM Test No. D1925, with the following results:
Y1 - (Yellowness) Rating Lot 1 2.5 Lot 2 2.5 Lot 3 2.2 Lot 4 2.1 Lot 5 1.9 Lot 6 1.9 Lots 1-6 2.2 (averaged) CONTROL 6.0
[0039] The above tests demonstrate the improvement in the reduction of imperfections and degradation upon producing polyolefin-based adhesive resins in accordance with the process of the present invention, as well as the improvement in the optical properties of the films of the adhesive, as compared to polyolefin-based adhesive resins produced according to heretofore known conventional methods. The above testing was performed by Equistar Chemicals, LP.
[0040] While the embodiment of the invention described herein is presently preferred, various modifications and improvements can be made without departing from the spirit and scope of the invention. The scope of the invention is indicated by the appended claims, and all changes that fall within the meaning and range of equivalents are intended to be embraced therein. | A method for producing polyolefin-based adhesive resins having improved physical and optical properties and the improved adhesive resins thereby produced, eliminates at least one reheating and melting of polyolefin polymer, comprises polymerizing a monomer composition of at least one olefin, mixing the polymerization product without pelletizing the polyolefin polymer with at least one graft polymer or copolymer in a heated mixing device at a temperature above the melting point of the components, and recovering the resulting polyolefin-based adhesive resin. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a self-standing keyboard support, which holds self-standing a keyboard which is an input device for a computer, and a keyboard equipped with said self standing support.
A keyboard, which is an input device for a personal computer or the like, is commonly placed, and used, on a desk, a side table, or a personal computer rack. However, even when a keyboard is not in use, it still occupies a certain space on the desk. This limits the workspace for an office worker, a problem of an ineffective use of the workspace. In other words, a keyboard not in use is not functional but stands in the way of office work.
2. Description of the Background Art
Attempts have been made to overcome this problem by holding the keyboard upright to open up the workspace on the desk. Japanese Patent Laid-Open Publication No. 2000-66813 discloses a self standing keyboard support which is provided, on the back of the keyboard, with a mounting portion which fits the back thereof said portion having a self-standing keyboard support built therein, and said self-standing keyboard support enabling the keyboard to stand upright.
However, this self-standing keyboard support, which is fitted into the back of the keyboard and is indented extensively as if it were to bore the keyboard, makes it inconvenient to operate the keyboard with said self-standing support attached thereto. Since said self-standing support is directed toward where the keyboard user's hands rest, it is unsightly and a distraction to work.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a self-standing keyboard support which can be easily attached to a keyboard, and a keyboard equipped with said self-standing support. It is another object of this invention to provide a self-standing keyboard support that enables one to operate the keyboard freely with no interference while the keyboard is fitted with the self-standing support, and a keyboard equipped with said self-standing support.
That is, the present invention relates to a self-standing keyboard support comprising:
an L-shaped band ( 9 ) and an L-shaped band ( 8 ) wherein
said L-shaped band ( 9 ) consisting of a flat band portion ( 4 ), which is a flat band shaped member, and an edge portion ( 3 ) which is formed at one end thereof at an angle to said flat band portion ( 4 ) and said L-shaped band ( 8 ) consisting of a flat band portion ( 7 ) and an edge portion ( 2 ) which is formed at one end thereof at an angle to said flat band portion ( 7 ) are arranged in such a way that the edge portion ( 3 ) faces the edge portion ( 2 ) with a designated distance apart therebetween;
the flat band portion ( 4 ) and the flat band portion ( 7 ) are joined together via a thin resilient strip ( 6 ) placed across the undersides of the edge portions ( 3 ) and ( 2 ).
The flat band portion ( 7 ) may be made longer than the flat band portion ( 4 ); the backside of the flat band portion ( 4 ) may be further provided with an adhesive portion ( 5 ). It is preferred for the flat band portion ( 7 ) to be 2.5-4.5 times as long as the flat band portion ( 4 ). In addition, the edge portion ( 2 ) may be made shorter than the edge portion ( 3 ), and the space between the edge portions ( 2 ) and ( 3 ) is preferably 0.17-0.65 times the exterior side length of the edge portion ( 2 ).
In a keyboard equipped with the above self-standing keyboard support, the L-shaped band ( 18 ) consisting of a flat band portion ( 13 ) and an edge portion ( 17 ) which is formed at one end thereof at an angle to the flat band portion ( 13 ) is joined to one side of a thin resilient strip ( 12 ) while the other side of said thin resilient strip ( 12 ) is secured embedded into the keyboard back portion ( 11 ); said embedded portion is provided with a protruding portion ( 14 ), and the end face of said protruding portion ( 14 ) and said edge portion ( 17 ) are arranged to face each other with a designated distance apart therebetween. The height of the protruding portion ( 14 ) preferably is equal to the height of the edge portion ( 17 ) minus the thickness of the flat band portion ( 13 ). In the keyboard equipped with the self-standing support, an indented portion ( 15 ) which is as deep as the sum of the thickness of the thin resilient strip ( 12 ) and the thickness of the flat band portion ( 13 ), is as wide as that of the flat band portion ( 13 ), and is as long as the sum of the distance from the L-shaped band ( 18 ) to the end face of the protruding portion ( 14 ) and the length of the flat band portion is formed on the backside portion of the keyboard ( 11 ). The space between the edge portion ( 17 ) and the end face of the protruding portion ( 14 ) is preferably 0.17-0.65 times the exterior side length of the edge portion ( 17 ). The angles formed by the flat band portion ( 4 ) and the edge portion ( 3 ), the flat band portion ( 7 ) and the edge portion ( 2 ), and the flat band portion ( 13 ) and the edge portion ( 17 ) are right angle, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 ( a ) and ( b ) illustrate a keyboard support of the present invention.
FIGS. 2 ( a ) and ( b ) illustrate the way the flat band portion of the self-standing support is open.
FIG. 3 illustrates a keyboard equipped with the self-standing keyboard support of this invention.
FIG. 4 illustrates a dimensional relationship where the flat band portion is open.
FIGS. 5 ( a ), ( b ), and ( c ) illustrate a keyboard equipped with another self-standing support of this invention.
FIGS. 6 ( a ) and ( b ) illustrate the way the flat band portion of a keyboard equipped with a self-standing support is opened.
FIG. 7 illustrates another example of a keyboard equipped with a self standing support.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiment of this invention is explained with reference to the attached drawings. FIG. 1 illustrates a self standing keyboard support 1 of this invention FIG. 1 ( a ) is a side view and the FIG. 1 ( b ) is a frontal view. The self-standing keyboard support 1 is formed by having an L-shaped band 9 consisting of a flat band portion 4 and an edge portion 3 which is formed at one end thereof at an approximately right angle to the band portion 4 and an L-shaped band 8 consisting of a flat band portion 7 and an edge portion 2 which is formed at one end thereof approximately at a right angle to said flat band portion 7 arranged in such a way that the edge portion 3 faces the edge portion 2 with a designated distance apart therebetween and having the flat band portion 4 and the flat band portion 7 joined together via a thin resilient strip 6 placed across the undersides of the edge portions 3 and 2 .
The thin resilient strip 6 placed across the undersides of edge portions 3 and 2 joins the flat band portion 4 to flat band portion 7 . The thin resilient strip should be long enough to join the flat band portion 4 to flat band portion 7 ; in FIG. 1, one end of the thin resilient strip reaches up to the center of the flat band portion 4 , but it may reach all the way to the end of the flat band portion 4 . An adhesive portion 5 may be provided on the thin resilient strip 6 . This used to mount the self-standing support 1 on a keyboard 10 . The adhesive portion 6 should be within a dimensional range nearly enough to completely cover the flat band portion 4 . The way the self-standing support 1 is mounted on keyboard 10 is illustrated in FIG. 3 .
The flat band portion 7 , the flat band portion 4 , edge portion 2 , edge portion 3 all have about the same dimensional width and sheet thicknesses, but the flat band portion 7 is preferred to be longer than the flat band portion 4 . The flat band portion 7 is made longer over the flat band portion 4 in view of assuring the self-standing stability of the keyboard.
The band portion 7 should be aimed at 2.5-4.5 times as long as the length of the flat band portion 4 .
The edge portion 2 and edge portion 3 are set up at a certain distance apart. This is designed, as illustrated in FIG. 3, when the self-standing support is mounted on Keyboard 10 , to cause the flat band portion 7 to open to a certain angle with respect to the keyboard for making the keyboard self standing. FIG. 2 illustrates the way the flat band portion 7 is open to a certain angle with respect to flat band portion 4 . The flat band portion 7 is opened, inwardly toward the edge portions 2 and 3 , at a certain angle with respect to the flat band portion 4 , with the end of the edge portion 2 bent at a right angle acting as a fulcrum. In this case, the end of the edge portion 2 hits the exterior face of edge portion 3 , which acts as a stopper to reach an angle beyond which no further opening can be made.
In order for the end of the edge portion 2 to come in contact with the exterior face of the edge portion 3 when the flat band portion 7 is opened, thereby acting as a stopper, the edge portion 2 should be made shorter in length than the edge portion 3 . The angle at which the flat band portion 7 opens is determined approximately by the length of the edge portion 2 and the space between the edge portion 2 and edge portion 3 . FIG. 4 shows that there is the relationship of Equation 1, where θ is an angle the flat band portion 7 makes to the vertical line, r is a length of edge portion 2 , and d is the distance between the edge portions 2 and 3 .
d=r sin θ (1)
In order for the keyboard 10 to be made self-standing in a stable manner, the angle of the flat band portion 7 opened with respect to the flat band portion 4 should be suitably selected. With the angle θ in FIG. 4 as a guide, an angle between 10° and 40° should be selected. In other words, the distance d between the edge portion 2 and edge portion 3 should be 0.17-0.65 times the length of edge portion 2 . The angle to which the flat band portion 7 is opened is suitably determined by taking into consideration the self standing stability of the keyboard 10 and condition of the work desk on which the personal computer is placed, on the basis of which one should suitably select the length of the edge portion 2 and the distance between edge portion 2 and edge portion 3 .
The keyboard is laid down horizontally when the self-standing keyboard is to be used. In this case, the flat band portion 7 returns to the original position by virtue of the resiliency of the thin resilient strip 6 , i.e., back to the state where the flat band portion 4 and flat band portion 7 are closed. The flat band portion 7 can be freely opened or closed through the function of the thin resilient strip 6 .
The self-standing support 1 used in this invention may be made of metal plastic, or ceramic. A metal support is preferred in terms of resistance to breakage in handling, particularly for resiliency retention of the thin resilient strip.
If made of metal, the thin resilient strip 6 should be welded to the L-shaped band 8 and likewise to 9 . If made of plastic or other material it should be joined together with an adhesive or the like. The thin resilient strip 6 should be made of a strip material used for springs. The adhesive portion 5 is suitably provided using a double-side adhesive type. One adhesive side is used for an adhesion to the support and the other adhesive side for adhesion to the keyboard. As the adhesion effect of the adhesive declines, the adhesion portion should be replaced with a fresh adhesive. It is obviously permissible not to provide an adhesive portion 5 but to directly apply adhesive to the exterior side of the thin resilient strip 6 on the back of the flat band portion 4 for adhesion to the keyboard back surface portion 11 .
FIG. 3 illustrates a keyboard 10 equipped with said self-standing support. The self-standing support 1 is joined to the keyboard backside portion 11 via the adhesive portion 5 . The self-standing support 1 is mounted on a position suitable for the keyboard 10 to be made self-standing. For the keyboard to be self-standing, the self-standing support 1 assumes an open state, as illustrated in FIG. 3, at a certain angle between the flat band portion 7 , which constitutes the self-standing support 1 , and the keyboard backside surface potion 11 . As explained above, the end of edge portion 2 comes in contact with the exterior face of the edge portion 3 to hold the flat band portion 7 at a constant angle to the keyboard 10 .
The keyboard 10 as equipped with this self-standing support 1 can be made self-standing or laid horizontally. The self-standing support 1 , which is joined via a thin resilient strip 6 , returns straight when the keyboard 10 is laid horizontally due to the function of the thin resilient strip, thereby causing no problem in laying down the keyboard 10 horizontally. For the keyboard 10 to be made self-standing, all one needs to do is to open the angle of the flat band portion 7 of the self-standing support 1 , whereupon the keyboard is made self-standing.
FIG. 5 illustrates a keyboard equipped with another self-standing support. FIG. 5 ( a ) is a side view and FIG. 5 ( b ) is a rear side view of the keyboard. The figures illustrate a keyboard equipped with a self-standing support with an arrangement where an L-shaped band ( 18 ) consisting of a flat band portion ( 13 ) and an edge portion ( 17 ) formed at one end thereof, at an approximately right angle to the flat band portion ( 13 ) is joined to one side of a thin resilient strip ( 12 ) while the other side of said thin resilient strip ( 12 ) is secured by being embedded into the keyboard backside portion ( 11 ) as shown in FIG. 6 . The keyboard backside portion is provided with a protruding portion ( 14 ); and the end face of said protruding portion ( 14 ) and said edge portion ( 17 ) are arranged to face each other with a designated distance apart therebetween.
A thin resilient strip 12 has one side thereof embedded beneath the protruding portion 14 with the other side joined to the L-shaped band 18 . This support can be molded in one piece when the keyboard is molded. If the thin resilient strip 12 and the L-shaped band 18 are made of metal they should be joined by welding. If it is made of plastic, it should be joined with an adhesive.
The end face of the protruding portion 14 and edge portion 17 are set up with a designated distance apart. This is designed to open the flat band portion 13 as illustrated in FIG. 6 ( a ) at a certain angle to the keyboard 10 . This condition is enlarged as shown in FIG. 6 ( b ). The flat band portion 13 is opened at a certain angle with respect to the edge face of the protruding portion 14 , with the part of edge portion 17 bent at a right angle acting as a fulcrum. In this case, the edge portion 17 hits the end surface of the protruding portion 14 , which acts as a stopper to reach an angle beyond which no further opening can be made.
The angle at which the flat band portion 13 opens is determined approximately by the space between the end face of the protruding portion 14 and edge portion 17 . In FIG. 6 ( b ), there is a relationship of Equation 1, where θ is an angle of the flat band portion 13 to the keyboard, r is an exterior length of the edge portion 17 , and d is the distance between the end face of the protruding portion 14 and the edge portion 17 .
In order for the keyboard 10 to be self-standing and stabilized, the angle θ should be between 10° and 40°. In other words, the distance d between the protruding portion 14 and the edge portion 17 should be 0.17-0.65 times the exterior length of edge portion 17 .
The indented portion 15 is arranged on the underside of the protruding portion 14 (see FIGS. 5 ˜ 7 ), is as long as the sum of the length of the flat band portion 13 and the distance between the flat band portion 13 and the end face of said protruding portion 14 , and is approximately as wide as the flat band portion 13 . Further, the sum of the depth of said indented portion 15 and the height of said protruding portion is approximately equal to the sum of the heights of the edge portion 17 and the flat band portion 13 and the thickness of the thin resilient strip 12 . When the keyboard 10 is laid horizontally, the L-shaped band 18 , which consists of the flat band portion 13 and an edge portion 17 formed at one end thereof and at an approximately right angle to the flat band portion 13 , can be stored in said indented portion 15 . The function of the thin resilient strip 12 permits the L-shaped band 18 to be freely placed in and taken out or stored in said indented portion 15 .
FIG. 5 shows that the length of the flat band portion 13 reaching up to the center of the length of keyboard 10 , but it can be made longer. An example of lengthening the flat band portion 13 is given in FIG. 7 . This length can be suitably selected, depending upon the way the keyboard is placed.
The keyboard equipped with the self-standing support of this invention provides excellent effects:
(1) The keyboard can be held upright when it gets in the way on the desk and the space saved thereby can be effectively utilized. (2) The keyboard can be used in the usual manner. (3) The self-standing support can be readily attached to the space beneath the keyboard, which usually does not interfere. (4) The keyboard equipped with the self-standing support does not require attaching anew a self-standing support.
In addition, (1) the self-standing support of this invention can be mounted over a very thin space on the bottom of a keyboard. (2) It has a simple structure and high stiffness. (3) It accommodates a variety of mounting methods, enabling a large area sheet to be mounted if the mounting strength is enhanced. (4) It permits using a variety of material for its fabrication although the support is commonly made of stainless steel sheet.
FEATURES OF THE INVENTION
As explained above, it is easy to mount the self-standing keyboard support of this invention. The keyboard equipped with the self-standing support can be left self-standing, with the benefit of active use of space on a confined desk on which the personal computer is placed. The keyboard has features in that while equipped with said self-standing support, it can be left self-standing or can be laid horizontally, a customary use condition. The keyboard can be easily operated without problems with said self-standing support remaining attached thereto. The keyboard equipped with the self-standing support can be made self-standing by an operation as simple as that of flipping the keyboard legs. | A self-standing keyboard support having two L-shaped bands each consisting of a flat band portion and an edge portion extending from one side thereof at an approximately right angle to the respective flat band portion, with the flat band portions preferably differing in length. The edge portions of the two L-shaped bands are arranged in such a way that the respective outer sides thereof face each other. A thin resilient strip is placed across sides of the two flat bands portions opposite from the sides from which the edge portions extend and underneath the edge portions to join the two L-shaped bands together. Further an adhesive portion can be provided on the rear side of the thin resilient strip, thereby enabling its installation on a keyboard. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for the preparation of ceramic cores intended to be used for the precision casting of parts produced by means of lost-wax casting processes.
2. Summary of the Prior Art
The application of such casting processes of which the general technical knowledge is well dissemeninated within the foundry art is intended primarily for the production of high precision parts and is especially suited to the manufacture of aeronautical parts.
One example of such applications is the provision within turbine blades of very complex internal cooling arrangements. The manufacture of such parts by foundry procedures using the lost-wax process requires the use of ceramic cores which in order to reproduce these cooling arrangements, have inevitably multiple cavities, thin walls and complex shapes. As a result these cores are very fragile and it follows that multiple handling or the application of stresses risk causing damage by rupture or carcking.
The formation of wax models enrobing cores of this type in the processes of the lost-wax type thus encounter difficulties in practical application which are not wholly resolved satisfactorily by the operational procedures hitherto applied. In practice, the fragility of the cores hinders the injection of the wax, during the enrobing operation of the cores by the modelling wax, to a pressure sufficient to enable compensation for volumetric shrinkage of the wax in the larger volumes where local thicknesses are much greater. Now these shrinkages cause defects in the shape which show up in the parts to be made in a nonacceptable manner and furthermore it is not always possible to apply correcting measures in a repetitive manner in such a way as to correct such defects.
One solution to this problem, which the practitioners of the technical art concerned have tentatively sought to apply. consists in filling manually with liquid wax all the cavities of the ceramic cores before the enrobing operation. But this manual operation apart from inconveniences of practical application taking into account the costs, the prolongation of the manufacturing cycles, gives rise to numerous handling operations increasing the risks of damage resulting from the fragility of the cores and gives rise to the necessity of effecting numerous retouching operations, while at the same time essentially relying upon the dexterity of an operator.
An object of the present invention is to provide a method for the preparation of ceramic cores which resolves the problems hereinafter discussed.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process for the production of ceramic cores intended for the casting of high precision parts by the lost-wax method, the process comprising the steps of:
(a) providing a core having cavities therein
(b) providing a flexible mould,
(c) by filling means of an injection moulding machine, the cavities of the core with modelling wax while the core is enclosed within the flexible mould, and
(d) the enrobing core with modelling wax.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 illustrates a basic ceramic core which can be used in the application of the preparation process in accordance with the invention;
FIG. 2 illustrates a mock-up or dummy core;
FIG. 3 illustrates, to an enlarged scale, a crosssection taken on the line III--III of the core illustrated in FIG. 2;
FIG. 4 illustrates a diagrammatic view of equipment for the casting around the mock-up or dummy core;
FIG. 5 is a cross-section taken on the line V--V of the equipment illustrated in FIG. 4;
FIG. 6 is a diagrammatic perspective view of the two parts of a mould;
FIG. 7 is a view for carrying out the operation of filling up which comprises the preparation process of ceramic cores in accordance with the invention;
FIG. 8 illustrates the operation finishing of the core after filling up; and
FIG. 9 illustrates an example of the final core prepared by the process according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The ceramic core 1 illustrated in FIG. 1 is one example of the application of the invention. This core 1 is used in a precision foundry for the casting of a turbine blade by a process of the lost-wax type. Such blades comprise complex internal cooling arrangements. The example illustrated thus has internal walls 1a and various flow baffles 1b and reinforcing members 1c which define internal cavities of the blade. Such members define corresponding cavities formed in the ceramic core 1 which thus has complex elements of very fine character from which considerable fragility must result.
In a foundry process, of the kind referred hereinbefore, a ceramic core 1 must be enrobed with modelling wax. In order to ensure satisfactory results and to avoid nonacceptable defects in the shape resulting from phenomena of volumetric shrinkage of the wax in relatively massive zones where local thicknesses are substantial and at the same time the fragility of the core imposes limitations upon the injection pressure of the wax, it becomes necessary to fill with wax all the cavities of the ceramic core 1.
FIGS. 2 and 3 illustrate a mock-up or dummy core 10 which is similar to the ceramic core which is to be prepared for use in the actual casting of the blades. This mock-up or dummy core 10 is used for the manufacture by a moulding operation of a mould of flexible material, for example of the silicone elastomer type.
FIGS. 4 and 5 illustrate one example of putting this operation into practice. Two mock-up or dummy cores 10 are placed in a moulding box 2 on a layer 3 separating the cores for the moulding box base. An existing method for moulding using an injection runner 10a (see FIG. 3) formed on one face of the mock-up or dummy core 10 enables the production of a first part 4 of the mould in elastomer which defines one face of the mould and then a second part 5 of the mould defining a second face of the mould, as is illustrated in FIG. 6. The mould 6 thus comprises impressions, respectively 6a and 6b, of the two opposed faces of a mock-up or dummy core 10. An injection runner 6c is similarly provided on the mould 6.
The process according to the invention consists in placing the fresh ceramic cores in a mould 6 of silicone elastomer and then placing the mould 6 onto the support plate 7a of a pressure injection moulding machine 7 illustrated only diagrammatically in FIG. 7. An injection head 7b of the machine is adapted to cooperate with the mould 6 and injects the liquid wax into the mould 6 where the runners 6c supply the wax to the thin passages leading to the cavities 1a, 1b or 1c of the ceramic core 1. The injection moulding machine 7 employed is of a sufficient capacity for the process and for adequate control of the injection pressure which lies between one and five bars. During the injection, a plate 7c of the injection moulding machine 7 applies a clamping pressure on the mould 6, of which the pressure value is a function of the injection pressure.
After injection of the wax and demoulding, a final retouching operation, as illustrated in FIG. 8, enables the elimination of injection runners connected to the prepared core and FIG. 9 illustrates the prepared core 11 ready for use in which the cavities have been filled with wax. FIG. 8 also illustrates the injection runners 6c, in outline.
The process according to the invention which has just been described provides numerous advantages in comparison with prior manual operations which were protracted and delicate. The cycle times are clearly reduced. The length of time for an average manual operation is estimated as between three to six minutes per core, while the process according to the invention reduces the operation to one half minute per core. The process reduces the need to handle the cores and as a consequence limits risks of breakage which are otherwise increased substantially as a result of the fragility of the cores. The deposit of wax produced is more regular and a repetitive quality which is reproducable is obtained.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A process is disclosed for the preparation of ceramic cores which includes injection by means of a press of low power of liquid wax into cavities of a ceramic core disposed in a mould of elastomer produced by moulding of a dummy core which is a replica of the core to be produced. | 1 |
BACKGROUND
[0001] 1. Technical Field
[0002] The disclosure relates generally to illumination, and more particularly to an illumination device with high heat-dissipation efficiency.
[0003] 2. Description of the Related Art
[0004] In general, an LED-based illumination device employs a heat-dissipation module, such as a fan, to dissipate heat generated by the LED. However, the fan is often fixed on the heat-dissipation module, making removal, cleaning, and maintenance difficult. If the fan fails, the LED can easily overheat, with shortened lifetime rapidly occurring. Thus, what is called for is an illumination device utilizing a heat dissipation system that can alleviate the limitations described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of an illumination device in accordance with a first embodiment of the disclosure.
[0006] FIG. 2 is an exploded view of the illumination device in FIG. 1 .
[0007] FIG. 3 is a cross-section of an illumination device in accordance with a second embodiment of the disclosure.
[0008] FIG. 4 is a cross-section of an illumination device in accordance with a third embodiment of the disclosure.
[0009] FIG. 5 is a cross-section of an illumination device in accordance with a fourth embodiment of the disclosure.
DETAILED DESCRIPTION
[0010] Referring to FIG. 1 and FIG. 2 , an illumination device 100 in accordance with a first embodiment of the disclosure includes a light source 11 and a heat-dissipation device 12 .
[0011] The light source 11 includes a plurality of light emitting diodes (LEDs) 111 and a substrate 112 . The substrate 112 includes a first surface 1121 and a second surface 1122 . The second surface 1122 is opposite to the first surface 1121 . The LEDs 111 are mounted on the first surface 1121 , and electrically connected to the substrate 112 . The first surface 1121 faces away from the heat-dissipation device 12 .
[0012] The heat-dissipation device 12 , mounted on the second surface 1122 and thermally connected to the substrate 112 , includes a plurality of cooling fins 121 , a hollow shell 123 , and an air impeller 125 , such as fan.
[0013] The cooling fins 121 are received in the hollow shell 123 .
[0014] The hollow shell 123 includes a first side surface 123 a , a second side surface 123 b , and an upper surface 123 c . The second side surface 123 b is opposite to the first side surface 123 a . The upper surface 123 c is adjacent to the first side surface 123 a and the second side surface 123 b . At least one inlet 122 is defined in the first side surface 123 a and at least one outlet 124 in the upper surface 123 c . Optimally, the at least one outlet 124 is located on the upper surface 123 c , configured away from the first side surface 123 a , and adjacent to the second side surface 123 b.
[0015] When the hollow shell 123 is in normal use, the upper surface 123 c is higher than the first side surface 123 a and the second surface 123 b.
[0016] The air impeller 125 is located on the upper surface 123 c , and out of the hollow shell 123 . Optimally, the air impeller 125 is located between the inlet 122 and the outlet 124 , and adjacent to the outlet 124 . In the first embodiment, the air impeller 125 is a fan mounted on the upper surface 123 c by screws or mounting rabbets.
[0017] When the heat generated by the LEDs 111 is dissipated into the air via the cooling fins 121 , the air temperature in the hollow shell 123 increases. The hot air rises to leave the hollow shell 123 through the outlet 124 , generating a convection loop. Further, the air impeller 125 accelerates the airflow around the outlet 124 . According to the Bernoulli principle, when the velocity of the air is increased, air pressure decreases; and when the velocity of the air is decreased, the air pressure is increased. Because there is a pressure difference, the air flows from high pressure to low pressure areas, and accordingly, the convection loop between the inside and outside of the hollow shell 123 is accelerated so as to exhaust the hot air from the hollow shell 123 .
[0018] The airflow direction C generated by the air impeller 125 is perpendicular to the airflow direction B generated by the heated air through the outlet 124 . The air impeller 125 exhausts the hot air along the airflow direction C. Cold air enters the hollow shell 123 via the inlet 122 . This shows that the air convection loop generated by the air impeller 125 accelerates the air circulation in the hollow shell 123 so as to dissipate the heat generated by the light source 11 more efficiently.
[0019] Referring to FIG. 3 , the illumination device 200 in accordance with a second embodiment of the disclosure includes a light source 21 and a heat-dissipation device 22 .
[0020] The light source 21 includes a plurality of LEDs 211 and a substrate 212 . The substrate 212 includes a first surface 2121 and a second surface 2122 . The second surface 2122 is opposite to the first surface 2121 . The LEDs 211 are mounted on the first surface 2121 , and electrically connected to the substrate 212 .
[0021] The heat-dissipation device 22 is located on the second surface 2122 , and thermally connected to the substrate 212 . The heat-dissipation device 22 includes a plurality of cooling fins 221 , a hollow shell 223 , and an air impeller 225 , such as a fan.
[0022] The cooling fins 221 are received in the hollow shell 223 .
[0023] The hollow shell 223 includes a first side surface 223 a and a second side surface 223 b . The second surface 223 b is opposite to the first side surface 223 a . At least one inlet 222 is located on the first side surface 223 a ; and at least one outlet 224 on the second side surface 223 b . Further, the location of the at least one outlet 224 is higher than the location of the at least one inlet 222 . The air impeller 225 is located on the second side surface 223 b , and located below the outlet 224 . The airflow direction C generated by air impeller 225 is perpendicular to the airflow direction B of the heated air through the outlet 224 .
[0024] The air impeller 225 exhausts the hot air along the airflow direction C thereof to effectively reduce air pressure in the hollow shell 223 . The cold air flows into the hollow shell 223 through the inlet 222 , and the convection loop is generated.
[0025] Referring to FIG. 4 , the illumination device 300 in accordance with a third embodiment of the disclosure, includes a light source 31 and a heat-dissipation device 32 .
[0026] The light source 31 includes a plurality of LEDs 311 and a substrate 312 . The substrate 312 includes a first surface 3121 and a second surface 3122 . The second surface 3122 is opposite to the first surface 3121 . The LEDs 311 are mounted on the first surface 3121 , and electrically connected to the substrate 312 .
[0027] The heat-dissipation device 32 is located on the second surface 3122 , and thermally connected to the substrate 312 . The heat-dissipation device 32 includes a plurality of cooling fins 321 , a hollow shell 323 , and an air impeller 325 , such as a fan.
[0028] The cooling fins 321 are received in the hollow shell 323 .
[0029] The hollow shell 323 includes a first side surface 323 a , a second side surface 323 b , and an upper surface 323 c . The second side surface 323 b is opposite to the first side surface 323 a . The upper surface 323 c is adjacent to the first side surface and the second surface 323 b . At least one inlet 322 is located on the first side surface 323 a ; and at least one outlet 324 on the upper surface 323 c . Optimally, the outlet 324 is located on the upper surface 323 c , away from the first side surface 323 a , and adjacent to the second side surface 323 b . In normal use, the upper surface 323 c is higher than the first surface 323 a and the second surface 323 b.
[0030] The air impeller 325 includes a fan 3251 and an air-nozzle 3252 . The end of the air-nozzle 3252 adjacent to the outlet 324 is rectangular, and with a small cross-section area. The end of the air-nozzle 3252 which is adjacent to fan 3251 is columnar, conical, and with a large cross-section. The shape is recognized as providing optimum compression of air flowing therethrough, increasing the pressure difference between the inside and outside of the hollow shell 323 . Thus the heat-dissipation efficiency of the illumination device 300 is increased effectively. The fan 3251 is received in the air-nozzle 3252 .
[0031] Referring to FIG. 5 , the illumination device 400 in accordance with a fourth embodiment of disclosure includes a light source 41 and a heat-dissipation device 42 .
[0032] The light source 41 includes a plurality of LEDs 411 and a substrate 412 . The substrate 412 includes a first surface 4121 and a second surface 4122 . The second surface 4122 is opposite to the first surface 4121 . The LEDs 411 are mounted on the first surface 4121 , and electrically connected to the substrate 412 .
[0033] The heat-dissipation device 42 is located on the second surface 4122 , and thermally connected to the substrate 412 . The heat-dissipation device 42 includes a plurality of cooling fins 421 , a hollow shell 423 , and an air impeller 425 , such as a fan.
[0034] The cooling fins 421 are received in the hollow shell 423 .
[0035] The hollow shell 423 includes a first side surface 423 a , a second side surface 423 b , and an upper surface 423 c . The second side surface 423 b is opposite to the first side surface 423 a . The upper surface 423 c is adjacent to the first side surface 423 a and the second side surface 423 b . Furthermore, at least one inlet 422 is located on the first side surface 423 a and at least one outlet 424 on the upper surface 423 c.
[0036] Optimally, the at least one outlet 424 is located on the upper surface 423 c , away from the first side surface 423 a , and adjacent to the second side surface 423 b . In normal use, the upper surface 423 c is higher than the first side surface 423 a and the second surface 423 b.
[0037] The air impeller 425 includes a fan 4251 and a bellow-shaped air-nozzle 4252 configured for housing the fan 4251 . The air-nozzle has a gradually decreased diameter toward the outlet 424 . The bellow-shaped air-nozzle 4252 accelerates airflow therethrough, increasing pressure difference between the inside and outside of hollow shell 423 . The heat-dissipation efficiency of illumination device 400 is improved accordingly.
[0038] While the disclosure has been described by way of example and in terms of exemplary embodiment, it is to be understood that the disclosure is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | An illumination device includes a light source and a heat-dissipation device. The heat-dissipation device has an air impeller configured for dissipating heat from the light source, and a hollow shell. The hollow shell has an inlet and an outlet with a height difference therebetween. The air impeller is removably installed on the shell between the inlet and outlet. The air impeller is adjacent to the outlet and accelerates airflow therefrom. Air pressure around the outlet is reduced and a pressure difference between the inside and outside of the hollow shell is generated. Air in hollow shell is heated by the light source and leaves the hollow shell via the outlet. Cold air enters the hollow shell via the inlet. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a cast for orthopedic leg injuries, and more particularly to an inflatable cast having a plurality of adjustable pressure air chambers contained within a resilient outer support casing which may easily be installed around a patient's lower extremity to control tissue edema and minor undisplaced fractures, acute sprains, and ruptures of supporting ligaments.
The traditional techniques of treating orthopedic leg injuries have revolved around three type of devices: casts, which have application primarily in broken legs; splints, which are utilized to immobilize and stabilize injuries; and pressure bandages, which are used both to control swelling and to present a degree of support, particularly to ankles. Splints and elastic bandages are often used in conjunction with each other. As in other areas of medicine, creative individuals have come up with a variety of departures from these standard themes in order to present better techniques of patient treatment.
One of the first alternative devices is taught in U.S. Pat. No. 3,561,435, to Nicholson. The Nicholson apparatus is an inflatable splint which holds a cooling medium, such as crushed ice, on its interior side. The inflatable splint fits over the patients lower leg, and is inflated both to stiffen the splint and to bring the cooling interior surface of the splint into intimate contact with the patient's leg. The Nicholson device is designed to be used only temporarily rather than over an extended period.
Another variation on the theme of a cast is illustrated in U.S. Pat. No. 3,643,656, to Young et al., and in U.S. Pat. No. 4,817,590, to Stancik, Jr. These devices are both one-time inflatable casts, which are each applied in similar fashion to a patient's lower leg in a loose-fitting manner. Following the initial installation, they both have an inflatable compartment for placement adjacent the patient's leg located in the interior of the cast filled with foam to closely fit against the patient's leg.
Young et al. uses the introduction of a foam-producing substance into the inflatable compartment to provide the close fit. Stancik, Jr. injects a material which hardens in the inflatable compartment, in a manner similar to that of the Young et al. reference.
These devices have a drawback which limits their application considerably. Both the Young et al. and the Stancik, Jr. devices are essentially replacements for a fixed shape cast, in that once the foam sets they will be in a fixed configuration. Thus, their only application is as a replacement for a fixed cast, and due to their added cost and lack of additional advantages they present no substantial advantage over standard casts. Additionally, they are inapplicable in situations where there is any substantial tissue swelling. Finally, they provide no support for the ankle, other than the mere presence of the inflatable compartments.
The problem of providing a variable and changeable inner configuration is solved at least in part through the use of an inflatable cast apparatus, with air-inflated inner chambers being used to place pressure on the leg. Such devices are disclosed in U.S. Pat. No. 3,580,248, to Larson, in U.S. Pat. No. 3,786,805, to Tourin, and in U.S. Pat. No. 3,955,565, to Johnson, Jr. The Larson and Johnson, Jr. '565 devices are remarkably similar, both having front and back hard shells which are fastened together with hardware (Larson) or straps (Johnson, Jr. '565) to enclose the lower leg and foot.
The Larson device has inflatable liners in each shell half covering the entire lower leg and most of the foot, while the Johnson, Jr. '565 device has inflatable air bags in each shell half extending the length of the lower leg. They both offer little adjustment for different size legs other than the inflatable compartments, and are really designed mainly to immobilize a patient's leg. They also provide no particular support for the ankle other the mere existence of the inflatable compartments, which provide little ankle support.
Differing somewhat from these hard shell designs is the Tourin apparatus, which has more parts than any of the other devices of this type known. Rather than using hard shells, the Tourin device uses a complex frame having front and back inflatable cushions supported from a frame. Tourin suffers some of the same deficiencies as the Larson and Johnson, Jr. '565 devices, and adds substantially to these deficiencies with its complexity, undoubted high cost of manufacture, and its difficulty of assembly.
As might be expected, the art has more recently produced devices which, although completely different, do provide ankle support alone. U.S. Pat. No. 4,628,945, to Johnson, Jr. (the same Johnson, Jr. as in the '565 patent) and U.S. Pat. No. 4,977,891, to Grim are examples of ankle braces using inflatable compartments. Johnson, Jr. '945 uses shell members with inflatable, partially foam-filled liners to provide ankle support, while Grim uses an ankle brace with inflatable bladders which are pumped up when the wearer walks or runs. Both devices are only suitable for ankle support, and are not intended for the same applications as that of the present invention.
It is accordingly the primary objective of the present invention that it provide an improved cast apparatus having inflatable cushioning support for the leg of a patient. As such, it is an objective that the inflatable cushioning for the patient's leg should be adjustable in pressure at any point in time over the entire period of use by the patient to allow the pressure to be used to control edema after the initial occurrence of an injury, and to provide continuing support as the healing process continues. The mechanism for providing the pressure to the cast apparatus should be easy and convenient to use, as well as being capable of precision in its operation to precisely adjust the pressure on the patient's leg.
It is a further objective of the cast apparatus of the present invention that it provide ankle support specifically designed for the ankle instead of mere air cushions which happen to bear in part against the ankle. The ankle support apparatus must be fully integrated in the cast apparatus of the present invention, and must further be capable of pressure adjustment independently of the inflatable cushioning provided for the leg of the patient.
It is yet another objective of the cast apparatus of the present invention that it be capable of providing support and cushioning for the foot of the patient. In addition to restricting the degree of movement and providing support for the patient's foot, the cast apparatus of the present invention should also present foot cushioning allowing the patient (with the approval of his of her physician) to place weight on the leg supported by the cast apparatus of the present invention. Like the ankle support apparatus, the foot cushioning and support apparatus must be fully integrated in the cast apparatus of the present invention, and must further be capable of pressure adjustment independently of the inflatable leg cushioning and the ankle support apparatus.
It is an additional objective of the adjustable cast of the present invention that it be easy both to install and to adjust on the leg of a patient. It should also be manufacturable of lightweight, non-rigid material which is both tough and durable to afford it excellent strength and durability. It is a further objective of the cast apparatus of the present invention that it offer the ability to use one or more rigid splints if desired, with the splints being easily installable in integrated fashion into the cast apparatus. Finally, it is also an objective that all of the aforesaid advantages and objectives of the present invention be achieved without incurring any substantial relative disadvantage.
It should be noted that this invention can readily be applied to other extremities, including the arm, wrist and hand, and should not be considered as limited to a leg and foot.
SUMMARY OF THE INVENTION
The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, an inflatable cast having a plurality of air chambers is designed to fit on the lower leg, preferably from just below the knee to the crease of the toes. The cast apparatus of the present invention has three completely separate sets of air chambers: a first set of multiple air chambers for providing adjustable cushioning for the leg of a patient; a second set of two air chambers for supporting the ankle of a patient; and a third set of multiple air chambers for providing both support and cushioning for the foot of a patient. All three sets of air chambers are independently inflatable.
The three sets of air chambers are located and supported between an external sleeve member made of non-rigid elastomeric material and an inner lining made of soft fabric material. Extending from the external sleeve member are three air fill valves. The air fill valve for the first set of air chambers is located at the proximal end of the cast apparatus, on the lateral side thereof. The air fill valves for the second and third sets of air chambers are located in the lower posterior side of the cast apparatus, near the heel of the cast apparatus.
The anterior portion of the cast apparatus which encases the leg has a longitudinal opening there to facilitate installation of the cast apparatus on a patient's leg. In the preferred embodiment, the foot portion of the cast apparatus is open only at the rear (although in an alternate embodiment the top surface of the foot portion of the cast apparatus also has an opening therein). The cast uses a Velcro-type material (Velcro being a trademark), with mating portions mounted on the inside of the cast apparatus adjacent one side of the longitudinal opening and on the outside of the cast apparatus adjacent the other side of the longitudinal opening.
This material is essentially a male and female type of fastener, with the female portion being a strip of material with curly strands or loops of material on the outer surface, and the male portion being a strip of material with a large number of flexible resilient plastic hooks on the outer surface, as illustrated in U.S. Pat. No. 3,063,718, to Steincamp. When the male and female strips of material are pressed against one another, the hooks in the male strip become entangled with the loops in the female strip, retaining the two strips together until they are forced apart.
The mating strip on the inside of the cast apparatus adjacent the one side of the longitudinal opening is placed over the mating strip on the outside of the cast apparatus adjacent the other side of the longitudinal opening to close the cast apparatus around the leg of a patient. This arrangement allows for some degree of size adjustment depending on the relative lateral alignment of the mating strips when they are placed together. Therefore, in the preferred embodiment, the mating strips are relatively wide to allow for a relatively large degree of adjustment to allow the cast apparatus to fit legs differing to some degree in size.
The cast apparatus also contains two additional elements in its primary embodiment. First, premolded ankle cups are located on the inside of each of the two air chambers in the second set of air chambers. These premolded cups are thus located between the air chambers and the fabric lining located on the interior of the cast apparatus, and are used to support the ankle bone prominence for both the lateral and the medial ankle malleolus. Secondly, a relatively thick reinforcing pad made of dense material and extending the length of the foot is used under the third set of air chambers to protect them if the patient places weight on the leg carrying the cast apparatus.
In another aspect, the cast apparatus allows for the use of one or more splint members in conjunction with the elastomeric external sleeve member to provide additional stiffness to the cast. The splint members may be made of metal or from a lightweight but relatively stiff plastic material. The splint members may be for anterior, posterior, lateral, or medial placement; indeed, more than one splint may be utilized to provide the desired therapy.
If desired, the elastomeric external sleeve member may be molded with one or more splint members located therein. This is particularly applicable to the use of the lateral and medial splint members. In the preferred embodiment, Velcro-type mating strips are located on the exterior surface of the elastomeric external sleeve member to facilitate the attachment of splint members having mating strips adhesively affixed thereon. In yet another embodiment, the elastomeric external sleeve member may be manufactured with a plurality of pockets located therein to receive one or more splint members. Additional straps may also be utilized to retain the splints in position on the cast apparatus.
If desired, a sock may be provided to cover the cast apparatus to keep it clean. Such a sock member may be made of durable fabric such as Nylon, with Velcro-type mating strips being used to close it when it is positioned around the cast apparatus. In order to prevent movement of the sock on the cast apparatus, thin foam rubber strips may be sewn into the inside of the sock so that they will make frictional contact with the exterior of the cast apparatus when the sock is installed in place.
The three sets of air chambers each have an air fill valve, as stated above. A bulb-type pump member may be used together with a pressure gauge and a segment of tubing having a connector on the distal end thereof to fill each set of the air chambers to a desired pressure level. In an alternate embodiment, an electric pump may be used instead to fill the three sets of air chambers. Such an electric pump may have a built-in electronic pressure gauge, as well as a printer to record the pressures in the three sets of air chambers.
It may therefore be seen that the present invention teaches an improved cast apparatus having inflatable cushioning support for the leg of a patient. As such, the inflatable cushioning for the patient's leg is completely adjustable in pressure at any point in time over the entire period of use by the patient, thereby allowing the pressure to be used both to control edema after the initial occurrence of an injury, and to provide continuing support as the healing process continues. The mechanism for providing the pressure to the cast apparatus is easy and convenient to use, and is capable of precision in its operation to precisely adjust the pressure on the patient's leg.
The cast apparatus of the present invention also provides ankle support specifically designed for the ankle instead of mere air cushions which happen to bear in part against the ankle. The ankle support apparatus is fully integrated in the cast apparatus of the present invention, and further is capable of pressure adjustment independently of the inflatable cushioning provided for the leg of the patient.
The cast apparatus of the present invention additionally is capable of providing both support and cushioning for the foot of the patient. In addition to restricting the degree of movement and providing support for the patient's foot, the cast apparatus of the present invention utilizes foot cushioning allowing the patient to place weight on the leg supported by the cast apparatus of the present invention. Like the ankle support apparatus, the foot cushioning and support apparatus is fully integrated in the cast apparatus of the present invention, and further is capable of pressure adjustment independently of the inflatable leg cushioning and the ankle support apparatus.
The adjustable cast of the present invention is easy to use, both in installing it on the leg of a patient, and in adjusting it after the initial installation. It may also be manufactured of lightweight, non-rigid material which is both tough and durable to afford the cast apparatus excellent strength and durability. The cast apparatus of the present invention additionally offers the ability to use one or more rigid splints if desired, with the splints being easily installable in integrated fashion into the cast apparatus. Finally, all of the aforesaid advantages and objectives of the present invention are achieved without incurring any substantial relative disadvantage.
DESCRIPTION OF THE DRAWINGS
These and other advantages of the present invention are best understood with reference to the drawings, in which:
FIG. 1 is a plan view of the three sets of air chambers used in the preferred embodiment, illustrating the first set of air chambers for cushioning the lower leg between the ankle and the knee, the second set of air chambers for cushioning the ankle, and the third set of air chambers for cushioning the bottom of the foot;
FIG. 2 is a schematic right side view of the three sets of air chambers shown in FIG. 1 located in the proper positions on the lower leg of a patient;
FIG. 3 is a schematic back view of the three sets of air chambers shown in FIG. 1 located in the proper positions on the lower leg of a patient;
FIG. 4 is a plan view of an alternate embodiment first set of air chambers for cushioning the lower leg between the ankle and the knee;
FIG. 5 is a schematic right side view similar to view of FIG. 2, but of the three sets of air chambers shown in FIG. 4 located in the proper positions on the lower leg of a patient;
FIG. 6 is a left side view of the cast apparatus of the present invention, which encloses the three sets of air chambers shown in FIGS. 1 through 3, installed on the lower leg of a patient, but with the longitudinal opening in the anterior portion of the cast apparatus remaining open for enhanced visibility, with two Velcro-type mating strips which are used to close the longitudinal opening also shown;
FIG. 7 is a cross-sectional view of the cast assembly shown in FIG. 6 showing the construction of the cast apparatus, including the air chambers and the cloth inner lining;
FIG. 8 is an exploded view of a bulb-type pump, a pressure gauge, and a segment of tubing having a connector at the distal end thereof, all for use in filling the air chambers of the cast apparatus shown in FIGS. 6 and 7;
FIG. 9 is a left side view of the cast apparatus shown in FIGS. 6 and 7, but with a plurality of splint members (shown only in part) located inside a plurality of pockets located in the elastomeric external sleeve member;
FIG. 10 is a left side view of the cast apparatus shown in FIGS. 6 and 7, but with a plurality of splint members (shown in hidden lines) located inside the elastomeric external sleeve member;
FIG. 11 is a left side view of the cast apparatus shown in FIGS. 6 and 7, but with a plurality of splint members (two of which are shown) having Velcro-type mating strips secured thereto attached to mating Velcro-type strips located on the outer surface of the elastomeric external sleeve member;
FIG. 12 is a plan view of a splint member for attachment to the cast apparatus shown in FIG. 11, showing a Velcro-type mating strip adhesively secured to one side thereof;
FIG. 13 is a left side plan view of the cast apparatus shown in FIGS. 6 and 7, with a sock member having Velcro-type mating strips to close the sock member when it is positioned around the cast apparatus, and also showing a foam rubber strip located on the inside of the sock to make frictional contact with the exterior of the cast apparatus to prevent movement of the sock on the cast apparatus; and
FIG. 14 is an electric pump for use instead of the apparatus shown in FIG. 8 to fill the air chambers of the cast apparatus shown in FIGS. 6 and 7.
FIG. 15 shows a modification of one set of air chamber to show it covering the instep and heel of a foot.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention utilizes three sets of air chambers which are illustrated in FIG. 1. A first set of air chambers 20 illustrated at the top of FIG. 1 is for cushioning the lower leg of a patient between the ankle and the knee. The first set of air chambers 20 includes an anterior leg air chamber 22, a lateral leg air chamber 24, a posterior leg air chamber 26, and a medial leg air chamber 28.
Each of the leg air chambers 22, 24, 26, and 28 is approximately ten inches long, and is of decreasing width from the proximal end (near the knee) to the distal end (near the ankle). The width of each of the leg air chambers 22, 24, 26, and 28 is just less than one-quarter of the circumference of a leg. Typically, since the cast apparatus of the present invention will be used on legs of widely varying sizes, it will be made in several different sizes, and thus each of the components may vary in size according to the approximate size leg the cast apparatus is designed to fit.
The leg air chambers 22, 24, 26, and 28 are preferably made of an elastomeric material such as medical grade silicone rubber. The leg air chambers 22, 24, 26, and 28 are preferably made of flat inner and outer segments which are fastened together in a sealing manner around the edges thereof. The leg air chambers 22, 24, 26, and 28 in the preferred embodiment may have inner segments which are narrower than the outer segments to cause the leg air chambers 22, 24, 26, and 28 to curve around the leg in a manner closely fitting the leg when the leg air chambers 22, 24, 26, and 28 are inflated.
The interiors of the leg air chambers 22, 24, 26, and 28 are interconnected with short segments of tubing extending between them. A first side of the anterior leg air chamber 22 is connected to a first side of the lateral leg air chamber 24 by a segment of tubing 30. A second side of the lateral leg air chamber 24 opposite the first side of the lateral leg air chamber 24 is connected to a first side of the posterior leg air chamber 26 by a segment of tubing 32. A second side of the posterior leg air chamber 26 opposite the first side of the posterior leg air chamber 26 is connected to a first side of the medial leg air chamber 28 by a segment of tubing 34.
Extending approximately two inches above the top edge of the lateral leg air chamber 24 is an air fill valve 36 which is for use in filling the leg air chambers 22, 24, 26, and 28. The air fill valve 36 preferably has a 1/4 inch valve stem, and is of standard design to allow air to pass therethrough when a filling hose is attached to the air fill valve 36. All four of the leg air chambers 22, 24, 26, and 28 may be simultaneously filled via the air fill valve 36.
Referring briefly to FIGS. 2 and 3, the first set of air chambers 20 is shown schematically as it will eventually be placed around the lower leg of a patient.
Shown in the center of FIG. 1 is a second set of air chambers 40 for cushioning the ankle of a patient on both sides thereof. The second set of air chambers 40 includes a lateral ankle air chamber 42 and a medial ankle air chamber 44. The ankle air chambers 42 and 44 are of roughly oval configuration, and are preferably made of flat inner and outer segments fastened together in a sealing manner around the edges thereof.
The ankle air chambers 42 and 44 in the preferred embodiment may have inner segments which are narrower than the outer segments to cause the ankle air chambers 42 and 44 to extend around the lateral and the medial ankle malleolus, respectively, in a concave manner to closely fit the lateral and the medial ankle malleolus, respectively, when the air chambers 42 and 44 are inflated. The ankle air chambers 42 and 44 are also preferably made of an elastomeric material such as medical grade silicone rubber.
The interiors of the ankle air chambers 42 and 44 are interconnected with a short segment of tubing 46 extending between the posterior side of the lateral ankle air chamber 42 and the posterior side of the medial ankle air chamber 44. Extending rearwardly approximately two inches from the center of the segment of tubing 46 is an air fill valve 48 which is for use in filling the ankle air chambers 42 and 44. The air fill valve 48 preferably has a 1/4 inch valve stem, and is of standard design to allow air to pass therethrough when a filling hose is attached to the air fill valve 48. Both of the ankle air chambers 42 and 44 may be simultaneously filled via the air fill valve 48.
Located on the inner side of the lateral ankle air chamber 42 is a lateral premolded ankle cup 50 for placement against the lateral ankle malleolus. Similarly, located on the inner side of the medial ankle air chamber 44 is a medial premolded ankle cup 52 for placement against the medial ankle malleolus. The premolded ankle cups 50 and 52 are made of a semirigid material such as polyurethane. The premolded ankle cups 50 and 52 are of roughly oval configuration, and are of a size somewhat smaller than the size of the ankle air chambers 42 and 44. The premolded ankle cups 50 and 52 are adhesively secured to the inner sides of the ankle air chambers 42 and 44, respectively.
Referring briefly again to FIGS. 2 and 3, the second set of air chambers 40 is shown schematically as it will eventually be placed around the ankle of a patient.
Shown at the bottom of FIG. 1 is a third set of air chambers 60 for cushioning for cushioning the bottom of the foot of a patient. The third set of air chambers 60 includes a first foot air chamber 62, a second foot air chamber 64, a third foot air chamber 66, a fourth foot air chamber 68, and a fifth foot air chamber 70. The foot air chambers 62, 64, 66, 68, and 70 are each of roughly oval configuration, with the wider sides of the foot air chambers 62, 64, 66, 68, and 70 being adjacent in consecutive manner (with the first foot air chamber 62 being nearest the heel and the fifth foot air chamber 70 being nearest the toes).
The widths of the wider sides of the foot air chambers 62, 64, 66, 68, and 70 vary to accommodate the widths of a foot. The widths of the shorter sides of the foot air chambers 62, 64, 66, 68, and 70 are each approximately 1/5 of the length of a foot. The foot air chambers 62, 64, 66, 68, and 70 are preferably made of flat inner and outer segments fastened together in a sealing manner around the edges thereof. The foot air chambers 62, 64, 66, 68, and 70 are preferably made of an elastomeric material such as medical grade silicone rubber.
The interiors of the foot air chambers 62, 64, 66, 68, and 70 are interconnected with very short segments of tubing extending between them. The front side of the first foot air chamber 62 is connected to the rear side of the second foot air chamber 64 by a segment of tubing 72. The front side of the second foot air chamber 64 is connected to the rear side of the third foot air chamber 66 by a segment of tubing 74. The front side of the third foot air chamber 66 is connected to the rear side of the fourth foot air chamber 68 by a segment of tubing 76. The front side of the fourth foot air chamber 68 is connected to the fifth foot air chamber 70 by a segment of tubing 78.
Extending approximately two inches behind the rear edge of the first foot air chamber 62 is an air fill valve 80 which is for use in filling the foot air chambers 62, 64, 66, 68, and 70. The air fill valve 80 preferably has a 1/4 inch valve stem, and is of standard design to allow air to pass therethrough when a filling hose is attached to the air fill valve 80. All five of the foot air chambers 62, 64, 66, 68, and 70 may be simultaneously filled via the air fill valve 80.
Referring briefly once more to FIGS. 2 and 3, the third set of air chambers 60 is shown schematically as it will eventually be placed under the foot of a patient.
Before detailing the construction of the rest of the cast apparatus of the present invention, an alternate embodiment for the first set of air chambers 20 illustrated in FIG. 4 will be discussed. An alternate first set of air chambers 90 illustrated in FIG. 4 has a plurality of leg tube sections, the interiors of which are interconnected to the interiors of adjacent leg tube sections. The alternate first set of air chambers 90 includes nine adjacent leg tube sections 92, 94, 96, 98, 100, 102, 104, 106, and 108.
Each of the leg tube sections 92, 94, 96, 98, 100, 102, 104, 106, and 108 is approximately ten inches long and approximately one inch in diameter, and if desired may be of decreasing diameter from the proximal end (near the knee) to the distal end (near the ankle). The leg tube sections 92, 94, 96, 98, 100, 102, 104, 106, and 108 are preferably made of an elastomeric material such as medical grade silicone rubber.
The interiors of the leg tube sections 92, 94, 96, 98, 100, 102, 104, 106, and 108 are interconnected with very short segments of tubing extending between them alternating between the proximal and distal ends thereof. The proximal ends of the leg tube section 92 and the leg tube section 94 are connected together by a segment of tubing 110. The distal ends of the leg tube section 94 and the leg tube section 96 are connected together by a segment of tubing 112. The proximal ends of the leg tube section 96 and the leg tube section 98 are connected together by a segment of tubing 114.
The distal ends of the leg tube section 98 and the leg tube section 100 are connected together by a segment of tubing 116. The proximal ends of the leg tube section 100 and the leg tube section 102 are connected together by a segment of tubing 118. The distal ends of the leg tube section 102 and the leg tube section 104 are connected together by a segment of tubing 120. The proximal ends of the leg tube section 104 and the leg tube section 106 are connected together by a segment of tubing 122. The distal ends of the leg tube section 106 and the leg tube section 108 are connected together by a segment of tubing 124.
Extending approximately two inches above the top of the leg tube section 98 is an air fill valve 126 which is for use in filling the leg tube sections 92, 94, 96, 98, 100, 102, 104, 106, and 108. The air fill valve 126 preferably has a 1/4 inch valve stem, and is of standard design to allow air to pass therethrough when a filling hose is attached to the air fill valve 126. All nine of the leg tube sections 92, 94, 96, 98, 100, 102, 104, 106, and 108 may be simultaneously filled via the air fill valve 126.
Referring briefly to FIG. 5, the alternate first set of air chambers 90 is shown schematically as it will eventually be placed around the lower leg of a patient.
Referring to FIG. 6, an assembled cast apparatus 130 is illustrated installed on the lower leg of a patient. The first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60 are installed within the cast apparatus 130 and are not visible in FIG. 6. The first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60 are installed in the cast apparatus 130 so that they are located around the leg of the patient in a manner similar to that illustrated in FIGS. 2 and 3 (or in FIG. 5).
The cast apparatus 130 supports the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60 between an external sleeve member 132 and an inner lining 134. The external sleeve member 132 is made of non-rigid elastomeric material, such as medical grade silicone rubber or natural rubber. The inner lining 134 is made of soft fabric material such as terry-cloth fabric, and is in the preferred embodiment made of 95% cotton and 5% Spandex to enable the fabric to stretch when the cast apparatus 130 is inflated. The external sleeve member 132 and the inner lining 134 are sewn together as shown to enclose the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60.
The portion of the external sleeve member 132 extending from just below the knee to the heel of the foot forms a tapered cylinder. The portion of the external sleeve member 132 covering the foot is boot-shaped, with the distal end being open to allow the toes to protrude therefrom. Seams 136 (one of which is shown in FIG. 6) located in both sides of the external sleeve member 132 join the leg portion of the external sleeve member 132 to the foot portion of the external sleeve member 132.
In the preferred embodiment illustrated in FIG. 6, the foot portion of the external sleeve member 132 is fully closed around the bottom, top, and sides of the foot. The foot portion of the external sleeve member 132 is thus open only at the rear to the interior of the leg portion of the external sleeve member 132, and at the front to allow the toes to protrude therefrom. The anterior portion of the leg portion of the external sleeve member 132 has a longitudinal opening there to facilitate installation of the cast apparatus 130 onto a patient's leg.
The longitudinal opening in the anterior portion of the leg portion of the external sleeve member 132 has a first edge 138 and a second edge 140. The external sleeve member 132 is sized to allow the first edge 138 to overlay the second edge 140 to close the cast apparatus 130 around the leg of the patient. When properly closed and before inflation of the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60, there will be approximately 5/8 of an inch of air space between the interior of the cast apparatus 130 and the leg (and also the foot) of the patient
The cast apparatus 130 uses Velcro-type material to close the longitudinal opening in the anterior portion of the leg portion of the external sleeve member 132. A first mating strip 142 of the Velcro-type material is mounted on the interior of the first edge 138 of the leg portion of the external sleeve member 132 of the cast apparatus 130, adjacent one side of the longitudinal opening. A second mating strip 144 of the Velcro-type material is mounted on the exterior of the second edge 140 of the leg portion of the external sleeve member 132 of the cast apparatus 130, adjacent the other side of the longitudinal opening.
In the preferred embodiment, the mating strips 142 and 144 are each approximately 21/2 inches wide by 121/2 inches long. The broad widths of the mating strips 142 and 144 allow for a considerable degree of adjustment to fit legs varying somewhat in size (although the cast apparatus 130 will typically be made in several different sizes).
Extending from the cast apparatus 130 are the three air fill valves 36 (or 126), 48, and 80. The air fill valve 36 (or the air fill valve 126) for the first set of air chambers 20 (or for the alternate first set of air chambers 90) is located at the proximal end of the cast apparatus 130, on the lateral side thereof (not shown in FIG. 6). The air fill valve 48 for the second set of air chambers 40 is located in the lower posterior side of the cast apparatus 130, near the back of the ankle of the cast apparatus 130. The air fill valve 80 for the third set of air chambers 60 is also located in the lower posterior side of the cast apparatus 130, near the back of the foot of the cast apparatus 130.
Referring now briefly to FIG. 7, the interior of the cast apparatus 130 is illustrated in a sectional view. Located on the bottom of the foot portion of the external sleeve member 132 is a dense reinforcing sole 146 which extends from the heel to the base of the toes under the bottom of the foot. The reinforcing sole 14 is approximately 1/16 inch thick, and is preferably made of synthetic rubber material.
As stated above, the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60 have air fill valves 36 (or 126), 48, and 80, respectively. Referring now to FIG. 8, a bulb-type pump member 150 may be used to fill the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60.
The bulb-type pump member 150 has a valve 152 which may be used to release pressure from the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60. Located at the base of the valve 152 is a male connector 154. A pressure gauge 156 is used to indicate the pressure in the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60. The pressure gauge 156 has a female connector 158 located on one side thereof and a male connector 160 located on the other side thereof.
A segment of tubing 162 approximately eighteen inches long has a female connector 164 located at a proximal end thereof and a air fill tube connector 166 located at a distal end thereof. The air fill tube connector 166 is designed to fit onto each of the air fill valves 36 (or 126), 48, and 80, to fill each of the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60, respectively, to a desired pressure level.
The pressure for each of the first set of air chambers 20 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60 typically will range between 18 PSI and 32 PSI, depending on the condition of the patient being treated. Accordingly, the pressure gauge 156 will typically read up to 40 PSI.
Referring now to FIG. 9, an alternate embodiment is illustrated which has a longitudinal opening in the top of the foot portion of the external sleeve member 132 to facilitate installation of the cast apparatus 130 onto a patient's foot. The longitudinal opening in the top of the foot portion of the external sleeve member 132 has a first edge 139 and a second edge 141. The external sleeve member 132 is sized to allow the first edge 13 to overlay the second edge 141 to close the cast apparatus 130 around the foot of the patient. When properly closed and before inflation of the third set of air chambers 60, there will be approximately 5/8 of an inch of air space between the interior of the cast apparatus 130 and the foot of the patient.
The cast apparatus 130 uses Velcro-type material to close the longitudinal opening in the top of the foot portion of the external sleeve member 132. A first mating strip 143 of the Velcro-type material is mounted on the interior of the first edge 139 of the foot portion of the external sleeve member 132 of the cast apparatus 130, adjacent one side of the longitudinal opening. A second mating strip 145 of the Velcro-type material is mounted on the exterior of the second edge 141 of the foot portion of the external sleeve member 132 of the cast apparatus 130, adjacent the other side of the longitudinal opening.
In the preferred embodiment, the mating strips 143 and 145 are each approximately 21/2 inches wide by 5 inches long. The broad widths of the mating strips 143 and 145 allow for a considerable degree of adjustment to fit feet varying somewhat in size.
In another aspect of the present invention, the cast apparatus 130 preferably allows for the use of one or more splint members in conjunction with the external sleeve member 132 to provide additional stiffness to the cast apparatus 130. Splint members may be made of metal or from a lightweight but relatively stiff plastic material. The splint members may be for anterior, posterior, lateral, or medial placement; indeed, more than one splint may be utilized in conjunction with the cast apparatus 130 of the present invention in order to provide the desired therapy.
Referring now to FIG. 10, the external sleeve member 132 is illustrated to have been molded with one or more splint members located therein. Specifically, in FIG. 10 the cast apparatus 130 is illustrated with an anterior splint member 170 molded into the anterior portion of the external sleeve member 132, a posterior splint member 172 molded into the posterior portion of the external sleeve member 132, and a medial splint member 174 molded into the medial portion of the external sleeve member 132. Although it is not shown in FIG. 9, a lateral splint member could also be molded into the lateral portion of the external sleeve member 132. The technique of molding splint members into the external sleeve member 132 is particularly applicable to the use of lateral and medial splint members.
In the preferred embodiment illustrated in FIG. 11, Velcro-type mating strips are located on the exterior surface of the external sleeve member 132 to facilitate the attachment of splint members having mating strips adhesively affixed thereon. Specifically, in FIG. 11 the cast apparatus 130 is illustrated with an anterior splint member 180 attached to the anterior portion of the external sleeve member 132 with Velcro-type mating strips, a posterior splint member 182 attached to the posterior portion of the external sleeve member 132 with Velcro-type mating strips, and a first Velcro-type mating strip 184 located on the medial portion of the external sleeve member 132.
A medial splint member 186 is illustrated in FIG. 12. The medial splint member 186 has a second Velcro-type mating strip 188 on the back side thereof, which second Velcro-type mating strip 188 is for attachment to the first mating strip 184 on the medial side of the external sleeve member 132 (FIG. 11) to attach the medial splint member 186 to the medial side of the external sleeve member 132. Although it is not shown in FIG. 11, a lateral splint member could also be attached to the lateral portion of the external sleeve member 132 with Velcro-type mating strips.
In yet another embodiment, the external sleeve member 132 may be manufactured with a plurality of pockets located therein to receive one or more splint members. Referring again to FIG. 9, the external sleeve member 132 is illustrated to have been molded with one or more splint members located therein. Specifically, in FIG. 9, the cast apparatus 130 is illustrated with a posterior splint member 190 located in a pocket 192 in the posterior portion of the external sleeve member 132, and a medial splint member 194 located in a pocket 196 in the medial portion of the external sleeve member 132. Although they are not shown in FIG. 9, an anterior splint member could be located in a pocket in the anterior portion of the external sleeve member 132, and a lateral splint member could be located in a pocket in the lateral portion of the external sleeve member 132.
Additionally, straps (not shown) may also be utilized to retain splints in position on the cast apparatus 130.
If desired, a sock may be provided to cover the cast apparatus to keep it clean. Such a sock member 200 is illustrated in FIG. 13. The sock member 200 may be made of durable fabric such as Nylon. In a preferred embodiment, the sock member 200 has a longitudinal opening in the anterior portion of the leg portion of the sock member 200 to facilitate installation of the sock member 200 onto the cast apparatus 130. The longitudinal opening in the anterior portion of the sock member 200 has a first edge 202 and a second edge 204. The sock member 200 is sized to allow the first edge 202 to overlay the second edge 20 to close the sock member 200 around the cast apparatus 130.
The sock member 200 uses Velcro-type material to close the longitudinal opening in the anterior portion of the sock member 200. A first mating strip 206 of the Velcro-type material is mounted on the interior of the first edge 202 of the anterior portion of the sock member 200, adjacent one side of the longitudinal opening. A second mating strip 208 of the Velcro-type material is mounted on the exterior of the second edge 204 of the anterior portion of the sock member 200, adjacent the other side of the longitudinal opening.
In order to prevent movement of the sock member 200 on the cast apparatus 130, thin foam rubber strips 210 may be sewn into the inside of the sock member 200 so that they will make frictional contact with the exterior of the cast apparatus 130 when the sock member 200 is installed in place.
In an alternate embodiment, an electric pump 220 may be used instead of the apparatus illustrated in FIG. 8 to fill the first set of air chambers 2 (or the alternate first set of air chambers 90), the second set of air chambers 40, and the third set of air chambers 60. The electric pump 220 has a built-in electronic pressure gauge 222 which may be calibrated in different units by using a button 224.
An on/off button 226 to turn the electric pump 220 on and off, a pump button 228 to actuate the pumping mechanism in the electric pump 220, an open button 230 to release pressure, and a memory button 232 to recall a preset pressure are included in the electric pump 220. The electric pump 220 may also include a built-in printer 234 to record the pressure, which is actuated by a printer button 236. The electric pump 220 has the distal end of a segment of tubing 238 attached thereto, the proximal end of which segment of tubing 238 may be attached to a connector such as the air fill tube connector 166 (FIG. 8).
It may therefore be appreciated from the above detailed description of the preferred embodiment of the present invention that it teaches an improved cast apparatus having inflatable cushioning support for the leg of a patient. As such, the inflatable cushioning for the patient's leg is completely adjustable in pressure at any point in time over the entire period of use by the patient, thereby allowing the pressure to be used both to control edema after the initial occurrence of an injury, and to provide continuing support as the healing process continues. The mechanism for providing the pressure to the cast apparatus is easy and convenient to use, and is capable of precision in its operation to precisely adjust the pressure on the patient's leg.
The cast apparatus of the present invention also provides ankle support specifically designed for the ankle instead of mere air cushions which happen to bear in part against the ankle. The ankle support apparatus is fully integrated in the cast apparatus of the present invention, and further is capable of pressure adjustment independently of the inflatable cushioning provided for the leg of the patient.
The cast apparatus of the present invention additionally is capable of providing both support and cushioning for the foot of the patient. In addition to restricting the degree of movement and providing support for the patient's foot, the cast apparatus of the present invention utilizes foot cushioning allowing the patient to place weight on the leg supported by the cast apparatus of the present invention. Like the ankle support apparatus, the foot cushioning and support apparatus is fully integrated in the cast apparatus of the present invention, and further is capable of pressure adjustment independently of the inflatable leg cushioning and the ankle support apparatus.
The adjustable cast of the present invention is easy to use, both in installing it on the leg of a patient, and in adjusting it after the initial installation. It may also be manufactured of lightweight, non-rigid material which is both tough and durable to afford the cast apparatus excellent strength and durability. The cast apparatus of the present invention additionally offers the ability to use one or more rigid splints if desired, with the splints being easily installable in integrated fashion into the cast apparatus. Finally, all of the aforesaid advantages and objectives of the present invention are achieved without incurring any substantial relative disadvantage.
Although an exemplary embodiment of the present invention has been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications, and alterations should therefore be seen as within the scope of the present invention. | A device for use as a cast for orthopedic leg injuries is disclosed which has a plurality of inflatable, adjustable pressure air chambers contained within a resilient outer support casing which may easily be installed around a patient's lower extremity to control tissue edema and minor undisplaced fractures, acute sprains, and ruptures of supporting ligaments. The cast apparatus of the present invention uses three sets of air chambers to support the lower leg, the ankle, and the lower foot, respectively, of a patient. The ankle portion of the cast apparatus has special support apparatus designed to provide excellent ankle support in a unique manner. Splint members may also be used in conjunction with the cast apparatus of the present invention, with a variety of techniques being used to mount the splint members onto the cast apparatus. The device can also readily be used as a cast for upper extremities. | 0 |
This application is a continuation of application Ser. No. 08/467,433, filed Jun. 6, 1995, now abandoned, which is a divisional of application Ser. No. 08/216,428, filed Mar. 23, 1994, abandoned.
BACKGROUND OF THE INVENTION
A conventional linear motion bearing shown in U.S. Pat. No. 4,253,709 has a large rigidity and can sustain a heavy load at a high speed with a high accuracy. Due to those excellent properties, it has been widely used especially in a field of machine tools.
One of the main features of the linear motion bearing is that it can provide a preload in the steel balls since the diameter of the steel ball is slightly larger than that of the raceway formed between the complementary grooves of the bearing body and the rail. Due to the preload, the assembled rigidity of the structure becomes larger which, in turn, enables to attain high accuracy.
On the other hand, one of the shortcomings of the linear motion bearing is in the usage of a retainer which holds or maintains the steel balls from falling off from the bearing body when it is withdrawn out of the rail.
The shape of the retainer can be either a plate structure as shown in FIG. 8 in U.S. Pat. No. 4,253,709 or a piano wire-like structure extending along the grooves as shown in U.S. Pat. No. 4,929,095.
These retainers are attached either to the bearing body or to the end caps. Because of this, the structure of the linear motion bearing becomes more complicated and more difficult to assemble a saddle from bearing body with steel balls by an automatic process.
Further, if the retainer dislocates its position, it may contact the steel balls and increases the friction. The retainer will be damaged or destroyed eventually. It also increases the cost of the linear motion bearing.
Another problem of the retainer lies in that the size of the radius of the curvature of the groove is inevitably limited due to existence of the retainer in the narrow raceway and so is the load rating.
It is well known that the retainer loses its function and becomes useless once the saddle is fit onto the rail since the steel balls are held solely by the complementary grooves.
Nevertheless, there must be a retainer since if the retainer is eliminated from the linear motion bearing, there is no way to maintain the steel balls within the bearing body of the saddle when it is withdrawn from the rail.
Yet another problem is how to fit the saddle onto the rail while maintaining the loose steel balls.
SUMMARY OF THE INVENTION
This invention is directed to a retainer-less linear motion bearing in which a retainer is completely eliminated from a bearing body. Instead, a ball holder independent of the bearing body, or a saddle, is used only when the saddle is withdrawn from the rail to retain the steel balls within the bearing body so as to prevent them from falling off when it is withdrawn from the rail.
This invention is also directed to a method for automatically assembling a complete saddle from a bearing body, end caps, steel balls and a ball holder.
Another object of the invention is to provide an adjustable ball holder which enables to reassemble the saddle at a working site without using any special devices.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a cross-sectional view of a saddle 6 with a ball holder 1 of the present invention.
FIG. 2 illustrates a perspective view of saddle 6.
FIG. 3 illustrates a perspective view of ball holder 1.
FIG. 4 illustrates a method to assemble saddle 6 onto rail R.
FIG. 5 illustrates a cross-sectional view of retainer-less linear bearing along X--X in FIG. 4.
FIG. 6 illustrates a perspective view of ball holder 1' made of rubber.
FIG. 7 illustrates a process to automatically assemble a saddle 6 from bearing body 4, end caps 5, 5, steel balls 7 . . . , and ball holder 1.
FIG. 8 illustrates a ball holder 11 provided with end plate 15.
FIG. 9 illustrates a detachable end plate 12.
FIG. 10 illustrates a ball holder 11' with a friction plate 14'.
FIG. 11 illustrates a ball holder 11" with an end plate 15" and a step portion 14".
FIG. 12 illustrates an adjustable ball holder 21.
FIG. 13 illustrates the deassembled state of adjustable ball holder 21.
FIG. 14 illustrates a contracted state of adjustable ball holder 21.
FIG. 15 illustrates a stop cover 28 for adjustable ball holder 21.
FIG. 16 illustrates second shaft 22' having fit plate 14'.
FIG. 17 illustrates adjustable ball holder 21" having tapered recess 24" and tapered projection 25".
FIG. 18 illustrates adjustable tubular ball holder 33 having a slit 35.
FIG. 19 illustrates adjustable tubular ball holder 43 made of a metal.
FIG. 20 illustrates adjustable tubular ball holder 43' having slits 46.
FIG. 21 illustrates a state when adjustable tubular ball holder 33 is placed within bearing body 4.
FIG. 22 illustrates insertion member 40 for adjustable tubular ball holder 33.
FIG. 23 illustrates insertion member 42 having recess 43 for adjustable ball holder 33 or 53 or 65.
FIG. 24 illustrates adjustable ball holder 53 having end plate 55.
FIG. 25 illustrates adjustable ball holder 53 having fit plate 65.
FIG. 26 illustrates another insertion member 70 with tapered recess 73.
FIG. 27 illustrates short insertion member 80 with recess 83.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment is directed to a ball holder 1 in which the raceway space formed by bearing body 4 and ball holder 1 is not adjustable.
FIG. 1 illustrates a cross-sectional view of a retainerless saddle 6 with a ball holder 1 according to this invention. FIG. 2 shows a perspective view of saddle 6. FIG. 3 shows a perspective view of ball holder 1. The cross-section of ball holder 1 is almost identical to that of track shaft part T, which is a top part of the rail R as shown in FIGS. 4 and 5. Ball holder 1 is formed by elongated shaft 2 and a plurality of grooves 3 . . . at about four corners of elongated shaft 2. The number of the grooves 3 . . . can be two or more depending upon that of track shaft part T or that of saddle 6.
The material of shaft 2 is preferably an elastic one such as soft plastic as shown in FIG. 3.
When saddle 6 is withdrawn from rail R, steel balls 7 are maintained by ball holder 1. The diameter of the raceway formed by a complementary groove 8 of bearing body 4 and a complementary grooves 3 of ball holder 1 is slightly smaller than that of a steel ball 7. Therefore, the grooves 3 . . . of ball holder 1 are slightly compressed by steel balls 7 . . . such that ball holder 1 is press fitted within saddle 6.
Also, since ball holder 1 is smaller than the cavity within bearing body 4 of saddle 6, in storing a plurality of saddles 6 . . . each having ball holder 1 therein, they can be placed one upon another. Thus, the storage to a plurality of saddles 6 . . . is very convenient and occupies less space according to this invention.
As shown in FIG. 4, in order to assemble saddle 6 onto rail R, saddle 6 is held by one hand of an operator while fitting the inner opening of end cap 5 onto track shaft part T of rail R and is moved toward rail R. As saddle 6 moves leftward in FIG. 4, steel balls 7 . . . are successively held within the raceways between the complementary grooves 8 . . . of saddle 6 and those of rail R, thus are preloaded since the diameter of each raceway is smaller than that of steel ball 7. Eventually ball holder 1 is completely removed from saddle 6 since it is stopped by the end surface of track shaft part T.
Thus, steel balls 7 . . . are maintained between rail R and bearing body 4 without a retainer as shown in FIG. 5.
In order to remove saddle 6 from rail R, ball holder 1 is first positioned at the end surface of track shaft part T. Then saddle 6 is moved rightward in FIG. 4 from rail R over ball holder 1 such that steel balls 7 . . . are successively held between the complementary grooves of saddle 6 and ball holder 1.
If shaft 2 is made of a material with a plenty of elasticity such as rubber, grooves 3 may be eliminated and instead they can be flat surfaces 3' as shown in FIG. 6.
Also shaft 2 can be made of a transparent material such that the steel balls 7 can be observed through the transparent body of shaft 2.
The length of ball holder 1 is at least the same to that of bearing body 4 or longer.
FIG. 7 illustrates the process for assembling saddle 6 from bearing body 4, end caps 5, steel balls 7 . . . and ball holder 1.
The process proceeds as follows:
Step 1. End cap 5 is attached at one end, preferably at a bottom end, of bearing body 4. Then it is fed, with, preferably, the attached end cap facing downward and an open end of bearing body 4 facing upward.
Step 2. Raceway Spacer A is inserted into the open cavity within bearing body 4 by Raceway Spacer Moving Device B. Raceway Spacer A is provided with a plurality of grooves 30 . . . each corresponding to each of grooves 8 . . . of bearing body 4. The diameter of each raceway space 9 formed by complementary grooves 30 and 8 is same or slightly larger than that of steel ball 7.
Step 3. Steel balls 7 are fed into raceway spaces 9 . . . and escape-ball through holes 10 . . . Due to end cap 5 attached at the bottom of bearing body 4, steel balls 7 . . . are easily fed by Ball Feed Device C into raceway spaces 9 . . . , escape-ball through holes 10 . . . and ball-recirculating grooves in end cap 5.
Step 4. Close top open end surface of bearing body 4 by a second end cap 5. It is preferable that ball-recirculating grooves in second end cap 5 are previously filled with steel balls 7. . . At this stage saddle 6 is formed by bearing body 4 and a pair of end caps 5, 5, Raceway Spacer A, and a plurality of steel balls 7 . . . , however, there is no preload provided in any of steel balls 7 . . . yet.
Step 5. Ball holder 1 is positioned at beneath of bottom end cap 5 and then saddle 6 is slid down onto ball holder 1. Since the material of ball holder 1 is much softer than that of steel balls 7 and of bearing body 4, ball holder 1 is slightly compressed without imparting much preload in steel balls 7 . . . so that it is firmly maintained within saddle 6 by friction.
It is preferable that ball holder 11 is further provided with end plate 15 at its one end as shown in FIG. 8. End plate 15 has a peripheral configuration substantially identical to the overall configuration of end cap 5.
Shaft 2 of the ball holder 2 can be made longer than that of saddle 6 and be provided at both distal ends with detachable end plates 12, 12 as shown in FIG. 9. Each of end plates 12, 12 has a shape substantially identical to the size of overall configuration of end cap 5 and is provided with a window 13 through which the distal end of shaft 2 fits with friction. Then the ball holder 1 can be maintained within saddle 6 with certainty since end plates 12, 12 holds saddle 6 therebetween.
One of end plate s 12, 12 can bs permanently fixed at a distal end of shaft 2.
Further, as shown in FIG. 10, a fit plate 14' can be provided at one end of shaft 2. Or step portion 14" can be provided between end plate 15" and shaft 20" as shown in FIG. 11. Fit plate 14' or step portion 14" abuts within the inner opening of end cap 5 in order to reinforce the frictional gripping. One advantage of the embodiments shown in FIGS. 10 and 11 is that it is easy to align the shaft with accuracy within the bearing body due to friction plate 14' or step portion 14" such that it makes it easier to reassemble saddle 6, the steel balls 7 . . . and ball holder 11' after saddle 6 was accidentally removed from the rail R without using ball holder 11' and steel balls 7 . . . fell off to the ground.
Next embodiments shown in FIGS. 12 through 20 are directed to the ball holder capable to provide adjustable raceway spaces.
FIG. 12 illustrates adjustable ball holder 21 composed of a pair of independent first and second shaft parts 22 and 23. First shaft part 22 is provided with a concave 24. Concave 24 is provided with a inclined bottom surface 28. On the other hand, second shaft 23 has inclined projection 25 which fits into concave 24. When first and second shaft 22 and 23 are assembled with both end surfaces flushing each other, they rest with a small clearance 26 therebetween and their combined end surfaces form a configuration substantially identical to that of track shaft part T of rail R.
As first and second shaft parts 22 and 23 are slightly dislocated from each other along their axial direction, clearance 26 is eliminated. Adjustable ball holder 21 of this contracted state is first inserted into the cavity of bearing body 4 and steel balls 7 . . . are fed into enlarged raceway spaces 9 . . . . Each of raceway spaces 9 . . . formed by grooves 31 . . . of adjustable ball holder 21 and grooves 8 . . . of bearing body 4 is slightly larger than steel balls 7 . . . so that filling of steel balls 7 . . . is easily accomplished.
After all raceway spaces 9 . . . and escape-ball through holes 10 . . . and ball-recirculating grooves in end cap 5 are filled with steel balls 7 . . . , another end cap 5 is fixed to cover the opening end of bearing body 4. Then first and second shaft parts 22 and 23 are axially slid until both end surfaces flush each other. The relative position of first and second shaft parts 22 and 23 is maintained by friction, or preferably by detachable screw 27. Alternatively, stop cover 28 as shown in FIG. 15 can be used instead of screw 27.
FIG. 16 shows another embodiment of second shaft 22' provided with fit plate 14' which fits into the inner opening of end cap 5.
FIG. 17 shows still another embodiment of first and second shaft 22" and 23" in which concave 24' and projection 25' are both tapered in their cross-sections.
FIG. 18 illustrates still further embodiment in which shaft 33 is somewhat tubular and has a cross-sectional configuration almost identical to that of track shaft part T of rail R except it has a cut opening 35 at its bottom formed by a pair of lips 34, 34. Provided at the four corners of ball holder 33 are grooves 35 . . . substantially identical to those of track shaft part T of rail R.
FIGS. 19 and 20 show different embodiments of such ball holder which are here made of metal. In FIG. 20, ball holder 43' is provided with windows 46 which enable easy holding of the steel balls 7 . . . .
In each of those embodiments, the outer configuration of ball holder 33 . . . is substantially identical to that of track shaft part T, however, becomes smaller when lips 34 and 34 are held to contact each other as shown in FIG. 21 such that the diameter of each raceway space 9 formed therein becomes slightly larger than that of steel ball 7. After steel balls 7 . . . are filled in the raceway spaces, lips 34 and 34 are released so that ball holder 33 springs back to its original shape and steel balls 7 . . . are held between bearing body 4 and ball holder 33.
FIG. 22 illustrates insertion member 40 to be inserted into clearance 35 between lips 34 and 34. Since the width of projection 41 of stop member 40 is slightly larger than clearance 35 between lips 34 and 34 after the steel balls 7 . . . are filled, ball holder 33 is even more firmly held in saddle 6 when stop insertion 40 is inserted.
Further, insertion member 40 prevents ball holder 33 from being deformed due to the resistance from preloaded steel balls 7 . . . when saddle 6 slides onto rail R and thus also prevents steel balls 7 . . . from falling off due to the possible deformation.
FIG. 23 illustrates another insertion member 42 having recess 43 and projection 44. Recess 43 works to hold lips 34 and 34 to contact each other.
FIG. 24 illustrates another embodiment of adjustable ball holder 53 having end plate 55 and a pair of separated cantilever projections 52, 52 projecting therefrom.
The outer configuration of end plate 55 is substantially identical to that of end cap 5 or of bearing body 4. Therefore, when ball holder 53 is inserted into saddle 6, with the position of side plate 55 exactly coincides with end cap 5, the positions of separated cantilever projections 52 and 52 are also determined in the exact locations to provide the raceways 9 . . . each slightly smaller than the diameter of steel balls 7 . . . .
Then the central clearance 57 between separated cantilever projections 52 and 52 is narrowed by holding lips 54 and 54 to contact each other in order to fill the steel balls 7 . . . into the slightly widened raceways 9 . . . . After completion of filling steel balls 7 . . . , lips 54 and 54 are released so that separated cantilever projections 52 and 52 hold steel balls 7 . . . against the grooves 8 . . . of bearing body 4.
FIG. 25 illustrates another embodiment of ball holder 63 provided with fit plate 65 which abuts with the inner opening of end cap 5 with friction. Also, cantilever projections 62, 62 are separated from fit plate 65 with clearance 66 such that cantilever projections 62 and 62 can be easily inclined.
FIG. 26 illustrates insertion member 70 having a projection 71 and tapered recess 73. The outer cross-section of insertion member 70 is identical to the inner cross-section of the inner cavity between cantilever projections 52 and 52 or 62 and 62.
First, clearance 57 or 67 is narrowed by moving tapered recess 73 onto lips 54 and 54 or 64 and 64. After steel balls 7 . . . are supplied, insertion member 70 is withdrawn from the lips. Then whole insertion member 70 is inserted into the inner cavity of cantilever projections 52 and 52 or 62 and 62 such that ball holder 53 or 63 hold steel balls 7 . . . more firmly.
FIG. 27 illustrates short insertion member 80 with recess 83. The length L of recess 83 is much shorter than the distance between the outer edges of the lips 54 and 54 or 64 and 64 in order to close clearance 57 or 67.
The width W of short insertion member 80 is slightly substantially identical to clearance 57 or 67. Thus when saddle 6 is assembled, short insertion member 80 is inserted into narrowed clearance 57 or 67 by steel balls 7 . . . so as to push the cantilever projections outwardly. | A ball holder for a retainerless saddle having an elongated shaft and a plurality of contact surfaces therearound to hold steel balls in cooperation with a bearing body only when the saddle is withdrawn from a rail. The shaft can be made of a hollow tube or a pair of cantilever projections so that the size of its cross-sectional area can be adjusted. Due to this adjustability the size of the raceways can also be adjusted to enable to reassemble the steel balls into the saddle at a working site. | 8 |
This application is a continuation of PCT/GB02/01475 filed Mar. 28, 2002.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to secure storage chambers for fixed installation within a compartment of a mobile vehicle, to kits of parts from which such storage chambers may be assembled, and to mobile vehicles having a vehicle compartment within which such a storage chamber shall have been installed.
The theft of valuable work tools, both mechanical and electro-mechanical, as well as other valuable items of substantial size, from mobile vehicles, notably motor vans, is commonplace, and it is the purpose of the present invention to offer a design for a secure storage chamber, being a chamber of a construction eminently well suited for installation, primarily, within a commodity carrying compartment of a van or other road vehicle.
SUMMARY OF THE INVENTION
Mobile vehicles, and kits of parts as aforesaid, are as set forth in the claiming clauses, or any of them, accompanying this Application and, accordingly, the content of said claiming clauses and the inter-relationships therebetween are to be regarded, notionally, as being here set forth, also.
A tradesman's van and, more specifically, a kit of parts adapted for assembly such as to constitute a fixed secure storage chamber installation within the carrying compartment thereof, are hereinafter described with reference to the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of a motor van within which is installed a diagrammatically represented safe storage chamber structure;
FIG. 2 shows, pictorially, the structure represented in FIG 1 , safe storage chamber wall panels being disjointed and folded to an unobtrusive compact configuration;
FIGS. 3 to 5 show, pictorially, the first, second and third steps in the erection of the safe storage chamber from the compact configuration of FIG. 2 , FIG. 5 being shown with part of the lid panel cut-away;
FIG. 6 shows the structure with the safe storage chamber in the fully erect configuration; and,
FIG. 7 shows the panel supporting frame of the installation.
DESCRIPTION OF THE INVENTION
The installation has a panel supporting frame ( FIG. 7 ) which comprises: a frame part 11 having first and second rigid, substantially L-shaped, square cross-section, mild steel, tubular side members 13 , 15 , suitably of 2.5 mm wall thickness, said side members being respectively contained in spaced parallel planes; a frame first cross-member 17 which bridges corresponding first limb portions 19 , 21 , respectively, of the L-shaped side members 13 , 15 at the forward ends thereof; and, a frame second cross-member 23 which bridges corresponding second limb portions 25 , 27 or the L-shaped frame side members 13 , 15 at the upper ends thereof.
The first limb portions 19 , 21 , and the first cross-member 17 of the frame, ate provided with a multiplicity of lugs 29 having passages adapted to receive bolt connectors (not shown) by means of which the installation, of which the frame 11 is part, is to be secured to the floor (not illustrated) of the vehicle compartment 31 (FIG. 1 ). When so secured, the first limb portions 19 , 21 , of the frame side members, and frame first cross-member 17 are contained in a horizontal plane, and the second limb portions 25 , 27 , of said frame side members, and the frame second cross-member 23 are contained in a vertical plane.
Attached to the frame 11 , there are, in the example, four panel members. Each of the aforesaid panel members comprises a body of flat sheet mild-steel, suitably of 2.5 mm gauge, and an endless mild-steel tubular sub-frame of square cross-section identical to that of the side frame members 13 , 15 , each sub-frame being of a size and shape such as to extend round the periphery of the body of sheet material, the sub-frame and the body being secured together by tack welds at intervals around the sub-frame.
One of the four panel members is a front panel member 33 the bottom member of whose box-section sub-frame is connected by spaced apart hinges 35 to the frame box-section first cross-member 17 , the hinges being such as to constrain the front panel member 33 for angular displacement between a first, or collapsed, position ( FIG. 2 ) at which the front panel member lies flat parallel with the compartment floor, and a second, or erect, position ( FIGS. 3 , 4 , and 5 ), at which the panel member 33 extends, transversely of the vehicle, upright with respect to the compartment floor. The sub-frame of the front panel member has, at its extremities, upstanding posts, as 37 .
First and second side panel members 39 , 41 , have their sub-frames respectively connected, at hinges, as 43 , to the sub-frame of the front panel member 33 adjacent to the side edges 45 , 47 , thereof.
It will be observed (FIG. 2 ), with the front panel member 33 in the collapsed state, the side panel members 39 , 41 , are such as each to lie with one major surface thereof in face to face contact with the compartment floor, and with the other in supporting face to face contact with the front panel member 33 .
Projecting from corresponding major surfaces of the side panels 39 , 41 , there are two posts (not shown) each provided with a diametral hole towards the free and thereof, and the front panel 33 has two passages, as 33 ′, at spaced locations such that with the front and side panel members in the collapsed position shown in FIG. 2 , the aforesaid posts are respectively received within said passages 33 ′, the free ends of the posts projecting proud of the front surface of the front panel 33 . Elongate wire clips (not shown) extend through the passages, the side and front panel members being thereby held for movement as one.
In swinging the front panel member 33 upwardly from the collapsed to the erect position, the aide panel members 39 , 41 , are compelled to follow. The second limb portions 25 , 27 , of the frame side members 13 , 15 , have inwardly extending transversely aligned lugs 49 , 51 , respectively, through which correspondingly located passages, as 53 , extend, and the sub-frames of the side panel members 39 , 41 , carry posts, as 55 , the positions of which are such as, when the front panel member 33 is in the upright position, to be able, respectively, to enter the passages 53 , the second limb portions 27 , 29 , of the frame side members 13 , 15 , thereby serving in the provision of rigid support for the hingedly connected front 33 and side panel members 39 , 41 .
The fourth panel member is constituted by the lid 57 . The lid 57 spans the space between the vertical, second limb portions 25 , 27 , of the frame side members 13 , 15 , being supported therebetween for angular displacement about a transverse axis X - - - X defined by transversely aligned first and second pivotal bearing arrangements, as 59 .
The lid 57 is angularly displaceable about the axis X - - - X between the vertical plane ( FIGS. 2 to 5 ) and the horizontal plane (FIG. 6 ). Projecting outwardly from the underside 61 of the lid 57 at or adjacent to the side edges thereof, there are first and second lugs 63 , 65 , respectively, and, projecting from the outer extremities of the upper edge of the lid panel 57 , there are apertured lugs 67 , 69 , respectively.
At the ends of the second cross-member 23 , bridging the frame side members 13 , 15 , there are elbow extension portions, as 71 , from which project apertured lugs, as 73 , these providing locations at which the second limb portions 25 , 27 , of the side members 13 , 15 , of the frame 11 may be secured, at the top, to side walls or other convenient structural parts of the vehicle compartment. Other features which should be mentioned are the lid handle 75 , latch means 77 for releasibly holding the lid 57 in the vertical plane, and a strong pad-locking means 79 which is for releasibly coupling the lid 57 and the front panel member 33 and which, in addition, serves as a handle for raising the front and side panel members as one from the collapsed position of FIG. 2 .
It should be noted, also, that the installation is, in the embodiment, devoid of a rear panel member. The lack of such a panel member arises from the circumstance that, in the example, the frame abuts a bulkhead or analogous wall separating the driver compartment from the compartment in which the frame 11 and the several said panel members are to be found. It will be noted, also, that, in the example, the front and side panel members have cut-away portions, this to accommodate the protrusion created by the rear 79 of the vehicle engine housing.
In other circumstances, of course, a rear panel member might be provided, the latter panel member comprising, in distinction from the front, side and lid panel members, a body of mid-steel sheet material secured, directly, as by tack welds (the rear panel member not being angularly displaceable a panel sub-frame would not then b required), to the forward faces of the second limb portions 25 , 27 , of the frame side members 13 , 15 . The absence of an engine housing protrusion, as 81 , would, of course, avoid the need for cut-aways in the front and side panel members.
The several Figures clearly show the conversion of the structure from a compact form ( FIG. 2 ) to the fully erect state ( FIGS. 3 to 5 ) at which a safe storage chamber emerges.
From the collapsed position (FIG. 2 ), the front 33 and side panel members 39 , 41 , are to be swung upwardly about the hinge axis of the front panel member. With the front panel member 33 in the vertical plane (FIG. 3 ), the side panel members 39 , 41 , may be swung outwardly about their parallel hinge axes with the front and side panel members given support by the inter-engagement between the posts 55 and lugs 49 .
With the front and side panel members thus supported, the lid panel member 57 is, after being freed from the frame 11 , by release of the latch means 77 , for angular movement about its pivot axis X - - - X, brought to contact with the upper rims of the front 33 and side panel members 39 , 41 , thereby to serve as the upper closure member of the chamber so formed with the posts 37 received within the apertures of the lid panel lugs 67 , 69 .
As indicated within the cut-away of FIG. 5 , in the course of bringing the lid panel 57 to the closure position, the lugs 63 , 65 , projecting from its underside, are brought to positions respectively lying in the paths of angular displacement of the side panel members 39 , 41 . With the chamber closed, and with the chamber pad-locked, the presence of the lugs 63 , 65 , secures the chamber against easy unauthorised access to valuables which may be held within the chamber, whilst, by folding the several hinged panel members to the positions shown in FIG. 2 , the front and side panel members being then flat with respect to the compartment floor, and the lid panel member being supported vertically against the frame 11 , the installation is unobtrusive and does not constitute an obstruction in the use of the compartment for work purposes.
It is to be observed that the elbow extension portions 69 , 71 , project upwardly from the cross-member 23 , the frame 11 being thereby provided with a step formation, which may be used to receive one end of lengthy items, such, for example, as a ladder to be transported.
Although not illustrated, the compartment may be provided with a second frame located at the opposite end of the compartment from the frame 11 of the aforedescribed installation. The additional frame would be hinged at its lower end to be displaceable between an erect lockable position and a position at which it is in contact with the compartment floor. The additional frame, when erect, would then serve to support the ladder or other lengthy item at its rear end. | A van is provided within its carrying compartment with an installation for use in the safe storage against theft of tradesmen's tools, such, for example, as electric drills. The installation comprises a substantially L-shaped frame, and several panels hingedly connected to the frame for movement between a collapsed, non obtrusive state in which chamber front and side panels are prostrate on, or adjacent to the compartment floor, and an erect state in which these are able to cooperated with a lid panel also hinged to the frame to create the chamber. | 1 |
FIELD OF THE INVENTION
The present invention relates to a contact member to be mounted on the surface of a printed circuit board and to achieve electrical conduction between a ground pattern on the printed circuit board and a grounding conductor.
BACKGROUND OF THE INVENTION
There is a conventionally known technique in which a contact member is mounted on the surface of a around pattern on a printed circuit board and, in that state, the printed circuit board is fixed in such a manner that the contact member is pressed against a grounding conductor, such as a chassis or the like. Thereby a ground pattern on the printed circuit board is electrically grounded to the grounding conductor via the contact member. Especially, in recent years, as more and more instruments having microcomputers built therein have been manufactured with the development of computer technology, the aforementioned technique is now indispensable for grounding printed circuit boards within such instruments.
This kind of contact member is likely to be formed by a conductive elastic sheet to ensure electrical conduction between a ground pattern on a printed circuit and a grounding conductor. Also, this contact member is sometimes combined with a conductive elastic body for the purpose of electromagnetic shield for use.
For example, in Publication of Japanese Unexamined Patent Application No. 2002-510873, situation is disclosed where a conductive gasket member is provided to a contact member made of plate metal in which a pair of spring-like finger parts are bent back from an end.
When a contact member is disposed between a ground pattern on a printed circuit and a grounding conductor such as a housing etc., tightening the cover of the housing by a bolt means risking that the contact member will be plastically deformed. This would result in the contact member losing its spring characteristics and not being able to elastically recover toward its original configuration. Once elastic resilience is lost, for example, when the housing is opened and closed repeatedly, the contact between the contact member and the housing may not be maintained, resulting in a chance of conductive failure.
The conductive gasket, disclosed in FIG. 10 of the Publication of Unexamined Japanese Patent Application No. 2002-510873, is considered by some to resist against the force which is attempting to crush a finger of the contact member. However, there is no reference in the above Japanese Patent Application to the problem of the case in which the elastic resilience of the finger is lost, and no description of measures to guard against the situation in which elastic resilience of the finger is lost.
SUMMARY OF THE INVENTION
An object of the present invention is to decrease the effect of plastic deformation of a contact member which is disposed between a ground pattern on a printed circuit board and a grounding conductor.
To attain the above and other objects, there is provided a contact member comprising a thin sheet member and an elastomeric body which may both be conductive and elastic. The thin sheet member includes a base part of which at least a portion is mounted on the surface of a ground pattern on a printed circuit board, a contact part which is provided facing the base part and becomes a joint area with a contact element on a surface providing a grounding conductor different from the printed circuit board on which the base part is mounted, and a supporting spring part which is connected to a part of the base part and to a base end of the contact part and which supports the contact part in such a manner that the contact part can be elastically deformed in the direction perpendicular to the plane of the base part. The elastomeric body is disposed between the base part and the contact part and is attached to the supporting spring part by allowing a part of the supporting spring part to penetrate through the inside of the elastomeric body.
A part of the base part is mounted on the surface of a ground pattern whereby this contact member is attached to a printed circuit board. By pressing a grounding conductor against the contact part provided facing the base part (for example, parallel to the base part), electrical conduction between a ground pattern on a printed circuit board and a grounding conductor is achieved.
The thin sheet member may preferably be composed of a single piece of sheet material. However, plural pieces of sheet material may be connected for use by spot welding or the like. The supporting spring part, which is connected to a part of the base part and to a base end of the contact part, supports the contact part in such a manner that the contact part can be elastically deformed in a direction perpendicular to the plane of the base part. Consequently, when the contact part is pressed by a grounding conductor, the contact part is elastically deformed in the direction of approaching the base part. The elastic repulsive force of the contact part caused by this deformation strengthens the contact between the contact part and a grounding conductor. As a consequence, the electrical conduction between a ground pattern and a grounding conductor can be favorably achieved.
When an external force is applied to elastically deform the contact part, the elastomeric body is elastically deformed. When the external force is released, the elastomeric body sustains an elastic recovery. Therefore, even if the force to elastically deform the contact part becomes excessive, the elastomeric body is a resistance against this force. As a result, it is avoided that the contact part is plastically deformed and that the spring characteristics of the contact part are lost.
In addition, even if the spring characteristics of the contact part are lowered and the recovery ability is decreased, the elastomeric body can compensate for the spring characteristics and provide a sufficient recovery ability. For this reason, if the spring characteristics of the contact part are lowered (or lost), the contact part can return toward its original configuration. Therefore, for example, when a housing is opened and closed repeatedly, the contact between the contact member and a grounding conductor is maintained, thus avoiding conductive failure.
Further in addition, the elastomeric body is attached to the supporting spring part by allowing a part of the support spring part to penetrate through the inside of the elastomeric body. As a result, for example, in spite of a repeated sequence of compression and release of the spring member, or other changes such as thermal expansion etc., there is little risk that the elastomeric body will be removed from the supporting spring part. In case of only using adhesive agents, there is a possibility that expansion and contraction changes may cause the adhesive agents to be removed.
Therefore it is not necessary to separately adhere the elastomeric body and the supporting spring part by adhesive agents or the like. Thus it is possible to use hard-to-adhere materials for the elastomeric body. Yet, the use of adhesive agents is not prohibited. Adhesive agents may be used based upon the material selections and operating environment of the elastomeric body.
In case of allowing a part of the supporting spring part to enter through the inside of the elastomeric body, the elastomeric body may be provided with a hole so that the entering part of the supporting spring part may pass through this hole. Alternatively, the elastomeric body may be provided with a groove deep enough that the entering part of the supporting spring part is contained, so that the supporting spring part may pass through this groove.
Also, a grounding conductor, which contacts and elastically deforms the supporting spring part, firstly abuts the supporting spring part, because the elastic body is only disposed between the base part and the supporting spring part. Therefore, the elastomeric body does not obstruct earth conduction between a grounding conductor and the supporting spring part.
Although it should be clear from this explanation, even though the elastomeric body may be made large enough to protrude beyond the base part or the contact part, it is preferable that the elastomeric body fits within the imaginary extended surfaces of the base part and of the contact part.
A basis of the material of the elastomeric body may be an elastomer. However, conductive particle and fiber such as filler etc. may be compounded therein for example. In case that conductive particles etc. are compounded into the elastomeric body or the like in order to achieve electrical conduction, the conductive distance between a ground pattern and a grounding conductor may become much shorter.
In the contact member, the elastomeric body is in contact with the contact part and the base part even in the state in which an external force needed to cause elastic deformation of the contact part is not applied to the contact member. As a result, when an external force which may elastically deform the contact part in the direction of the base part is subjected to the contact member, the external force immediately acts upon the elastomeric body as well. Therefore, the function of the elastomer body is performed more favorably.
In the contact member, the contact part comprises an attachment surface which can be grasped by an automatic mounting machine. This enables the contact member to be mounted on a printed circuit board using the automatic mounting machine.
In the contact member, the attachment surface and the base part are approximately parallel to each other in an unloaded state. Moreover, the attachment surface is set to maintain a substantially parallel relationship relative to the base part even when the contact part is elastically deformed in the direction of approaching the base part. Therefore, even if an elastic deformation is caused by abutment of the vacuum suction nozzle of the vacuum suction automatic mounting machine, gaps between the nozzle and the attachment surface are restrained. Because of this, the grasp of the contact member can be performed relatively efficiently. Thereby efficiency in the overall automatic mounting operation can be improved.
In the contact member, the elastomeric body is provided with a hollow part in a portion thereof under the contact part.
When the elastomeric body is compressively deformed, the hollow part provided to the elastomeric body in the portion under the contact part becomes a deformation allowing space for the elastomeric body. As a result, when the supporting spring part is elastically deformed in the direction that makes the contact part move closer to the base part, the initial resistance of the elastomeric body is decreased. In short, the ability to prevent the plastic deformation of the end portion of the contact part is enhanced because an excessive force is not applied by the elastomeric body to the supporting spring part and/or the contact part.
Preferably by allowing a portion of the elastomeric body located under the end part of the contact part to be the hollow part, an excessive force is inhibited from being applied to the end part of the contact part. As long as the hollow part is constructed so as to become the deformation allowing space when the elastic body is compressively deformed, the hollow part is not limited to a specific configuration and size. However, if the hollow part is configured to have a cavity in which at least one end is opened, the hollow part can be formed by injection molding.
In the contact member, the hollow part is preferably a longitudinal hole penetrating from the base part to the contact part. Therefore, the aforementioned effect of allowing injection molding, achieved by having a hollow shape in which at least one end is opened, can be obtained.
In the contact member, the hollow part is preferably a side hole penetrating along a direction perpendicular to the displacement direction of the supporting spring part when the supporting spring part is elastically deformed. This is the direction in which the contact part approaches and retreats from the base part. In addition, the ability to injection mold, achieved by having a hollow shape in which at least one end is opened, can be obtained.
Alternatively, in the early stage of the compressive deformation of the elastomeric body, the side hole is not greatly contracted. Thus, the resistance of the elastomeric body against this deformation is initially small, preferably helping to prevent excessive force from being applied to the supporting spring part as well as to the contact part, and also helping to reduce the amount of initial plastic deformation. On the other hand, if the compressive deformation of the elastomeric body continues to increase, whereby the side hole is substantially contracted, the resistance of the elastomeric body against the deformation force becomes much greater, thus preventing the excessive deformation (for example, crushing) of the supporting spring part. The function of inhibiting excessive deformation is valid for the contact part as well.
In the contact member of the present invention, at least a part of the base part is mounted on the surface of a ground pattern on a printed circuit board. This mounting is usually performed by soldering. Therefore, it is preferable that materials resistant to the heating caused by the soldering operation (generally a maximum temperature of about 260° C.) should be used for the elastomeric body.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1A is a perspective view of a thin sheet member of a contact member according to a first embodiment of the invention;
FIG. 1B is a top perspective view of the contact member according to the first embodiment of the invention;
FIG. 1C is a bottom perspective view of the contact member shown in FIG. 1B ;
FIG. 2A is a cross sectional view taken along line IIA—IIA in FIG. 1B showing the state in which the contact member, according to the first embodiment of the invention, is mounted on a printed circuit board;
FIG. 2B and FIG. 2C are explanatory views according to the first embodiment of the invention at the time that the deforming amount of the contact member is respectively small and large;
FIG. 3A and FIG. 3B are a top perspective view and a bottom perspective view of the contact member according to a second embodiment of the invention;
FIG. 4A is a cross sectional view according to the second embodiment of the invention showing the state in which the contact member is mounted on a printed circuit board;
FIG. 4B and 4C are explanatory views according to the second embodiment of the invention at the time the deforming amount of the contact member is respectively small and large;
FIG. 5A and FIG. 5B are a top perspective view and a bottom perspective view of the contact member according to a third embodiment of the invention;
FIG. 6A is a cross-sectional view showing the state in which the contact member is mounted on a printed circuit board, according to the third embodiment of the invention;
FIG. 6B is an explanatory view at the time the deforming amount of the contact member is small, according to the third embodiment of the invention;
FIG. 6C is an explanatory view to show the case in which an elastomeric body without a hollow cavity is used for comparison;
FIG. 7 is a perspective view showing the entire appearance of the contact member according to a fourth embodiment of the invention;
FIG. 8A is a plan view of the contact member according to the fourth embodiment of the invention;
FIG. 8B is a side view of the contact member according to the fourth embodiment of the invention;
FIG. 8C is a cross-sectional view taken along line IIIC—IIIC of the contact member according to the fourth embodiment of the invention;
FIG. 9A is an explanatory view of the contact member according to the fourth embodiment of the invention;
FIG. 9B is an explanatory view of the contact member of a comparative example without an elastomeric body for comparison;
FIGS. 10A , 10 B and 10 C are explanatory views of modified examples of the thin sheet member;
FIGS. 11A , 11 B, 11 C and 11 D are explanatory views of modified examples of the elastomeric body;
FIG. 12 is an explanatory view of modified examples of the elastomeric body;
FIGS. 13A and 13B are graphs of a compressive and recovery experiment of the contact member according to the fourth embodiment of the invention; and
FIGS. 14A and 14B are graphs of a compressive and recovery experiment of the contact member of a comparative example.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[First Embodiment]
As illustrated in FIGS. 1A , 1 B, and 1 C, a contact member 70 comprises a thin sheet member 80 and an elastomeric body 90 .
The thin sheet member 80 may be made of plate metal (a material such as beryllium copper and phosphor bronze for example) and its thickness may be in the range of 0.3 mm to 0.8 mm. Known press operation, such as stamping out and bending or the like, is performed to the thin sheet member 80 . A base part 81 , a supporting spring part 82 , and a contact part 83 are provided thereto.
The base part 81 may have a substantially rectangular shape. In the middle area thereof, a longitudinal hole 81 a, having a substantially rectangular shape, is formed by cutting and raising the supporting spring part 82 and the contact part 83 . Therefore, a joint surface 81 b, which is to be soldered to a circuit pattern on a printed circuit board, is the undersurface of the surrounding area of the longitudinal hole 81 a.
The supporting spring part 82 is an incline connected to the base part 81 at one side of the longitudinal hole 81 a. The end portion of the supporting spring part 82 is bent approximately parallel to the base part 81 , forming the flat contact part 83 .
The supporting spring part 82 can be elastically deformed in a direction causing the contact part 83 to move closer to the base part 81 (the joint surface 81 b ) or in the opposite direction about an area in which the supporting spring part 82 is connected to the base part 81 . The elastomeric body 90 , having a shape of a square frustum, is preferably a silicone elastomer which resists heating to 260° C. In the middle area thereof, is provided a side hole 91 having a shape of approximately a rectangular prism. The side hole 91 has openings at total three places; two places facing the sides perpendicular to the side of the longitudinal hole 81 a connected to the supporting spring part 82 , and one place having an opening in the middle area of the longitudinal hole 81 a at the undersurface of the elastomeric body 90 .
Also, as illustrated in FIG. 2A , a joint hole 94 is provided in the elastomeric body 90 . The supporting spring part 82 penetrates through this joint hole 94 allowing the elastomeric body 90 to be attached to the thin sheet member 80 .
Moreover, the bottom of the elastomeric body 90 fits within the longitudinal hole 81 a. This also enables the combination of the elastomeric body 90 with the thin sheet member 80 .
This contact member 70 is mounted for use on a printed circuit board 60 as illustrated in FIGS. 2A , 2 B, and 2 C. An attachment surface, more specifically, the upper surface of the contact part 83 (along with the upper surface 92 of the elastomeric body 90 ), is grasped by means of a vacuum suction automatic mounting machine in order to convey the contact member 70 . This contact member 70 is disposed onto the printed circuit board 50 in such a manner that a joint surface 81 b is in contact with solder paste located on a circuit pattern. The solder paste is melted by reflow soldering and cooled. Thereby, the contact member 70 is soldered to the printed circuit board 50 . In FIGS. 2A , 2 B, and 2 C, the circuit pattern 51 and the solder paste 51 a disposed between the joint surface 81 b and the printed circuit board 50 are not shown in order to simplify the figures.
In the contact member 70 mounted onto the surface of the printed circuit board 50 in the aforementioned manner, the contact part 83 is pressed against a grounding conductor 60 , such as a housing or the like, by the closing of the housing accommodating the printed circuit board 50 .
The distance between the printed circuit board 50 and the grounding conductor 60 interposing the contact member 70 therebetween is set to be smaller than the height of the contact member 70 when it is not subjected to an external force. Consequently, a pressing force from the assembled grounding conductor 60 is applied to the contact part 83 .
Because of this pressing force, as shown in FIG. 2B , the supporting spring part 82 is elastically deformed in such a manner that it rotates around the connecting part between the supporting spring part 82 and the base part 81 . Additionally, this pressing force acts upon the elastomeric body 90 either through the supporting spring part 82 and the contact part 83 , or directly, resulting in the elastic deformation of the elastomeric body 90 as though it were crushed.
The pressing force applied to the contact part 83 acts upon the elastomeric body 90 as well, so that the elastomeric body 90 adds to the resistance and the contact member 70 is not excessively deformed. Therefore, even if the force to elastically deform the contact member 70 becomes excessive as in the case above, the contact part 83 and the supporting spring part 82 avoid being only plastically deformed and losing a great deal of their spring characteristics.
When the elastomeric body 90 is elastically deformed in this way, the side hole 91 becomes a deformation allowing space for the elastomeric body 90 . As a result, when the supporting spring part 82 is elastically deformed in the direction that drives the contact part 83 closer to the base part 81 , the resistance of the elastomeric body 90 is initially decreased. In short, because an excessive force is not applied by the elastomeric body 90 to the supporting spring part 82 and the contact part 83 , the ability to inhibit the plastic deformation of these parts is enhanced.
Also, when the amount of elastic deformation of the contact member 70 by a pressing force is small (at the early stage of deformation) as illustrated in FIG. 2B , the existence of the side hole 91 facilitates the deformation of the elastomeric body 90 , thus allowing the elastomeric body 90 to be deformed as shown with little force.
When the amount of deformation is large, as illustrated in FIG. 2C , the inner walls of the side hole 91 come into contact with each other. Thus, the elastic repulsive force of the elastomeric body 90 gets larger than before and provides support for the contact part 83 as well as for the supporting spring part 82 . Therefore, the elastomeric body 90 inhibits these parts from being deformed beyond the elastic limit; in other words, plastic deformation of the supporting spring part 82 and the contact part 83 is suppressed.
Although the elastomeric body 90 is disposed on the upper side of the base part 81 , the grounding conductor 60 , which elastically deforms the contact member 70 , firstly abuts the contact part 83 (and the upper face 92 of the elastomeric body 90 ). Therefore, the elastomeric body 90 does not disturb the electric contact between the grounding conductor 60 and the contact part 83 .
After the grounding conductor 60 is removed from the contact member 70 and the pressing force is released by the opening of the housing or the like, the elastomeric body 90 goes through an elastic recovery. Accordingly, even if the spring characteristics of the supporting spring part 82 , which was deformed by the pressure of the grounding conductor 60 , are lowered and the recovery ability of the supporting spring part 82 is decreased, the elastomeric body 90 compensates for the lost spring characteristics and provides a sufficient recovery ability. For this reason, even if the spring characteristics of the thin sheet member 80 are decreased (or lost), the contact part 83 can return toward its original state. Therefore, for example, when the housing is opened and closed repeatedly, the contact between the contact member 70 and the grounding conductor 60 is maintained, inhibiting conductive failure
Furthermore, as the elastomeric body 90 is attached to the supporting spring part 82 by allowing a part of the supporting spring part 82 to penetrate into the joint hole 94 , there is relatively no risk that the elastomeric body 90 is unintentionally removed from the supporting spring part 82 (in short, from the entire thin sheet member 80 ) because of either adhesion failure or deterioration of an adhesive. There is no need to separately adhere the elastomeric body 90 and the supporting spring part 82 with an adhesive or the like, so it is possible to use hard-to-adhere materials for the elastomeric body 90 .
In the present embodiment, such a configuration is adopted that the elastomeric body 90 is in contact with the contact part 83 and the base part 81 even in the state in which an eternal force, which would cause the contact member 70 to be elastically deformed, is not applied to the contact member 70 . Consequently, when an external force, which would cause the contact part 83 to be elastically deformed in the direction of the base part 81 , is applied, it is immediately applied to the elastomeric body 90 as well.
Such a configuration may also be adopted that the elastomeric body 90 is in contact with neither the contact part 83 nor the base part 81 in an unloaded state. In this configuration, after the contact part 83 is displaced toward the base part 81 by more than a predetermined amount, the external force of the elastic deformation is applied to the elastomeric body 90 as well. By doing this, for example, when the amount of displacement of the contact part 83 (and/or the amount of elastic deformation of the supporting spring part 82 ) is small, only the elastic repulsive force of the thin sheet member 80 maintains the abutting conduction between the contact part 83 and the grounding conductor 60 . Subsequently, the elastomeric body 90 inhibits the amount of elastic deformation of the supporting spring part 82 which would be considered excessive.
Furthermore, the upper surface of the contact part 83 of the contact member 70 in the present embodiment is flat. This upper surface becomes an attachment surface that can be grasped with an automatic mounting machine. Therefore, the flat upper surface is grasped by the automatic mounting machine, allowing the contact member 70 to be automatically mounted on the printed circuit board 50 . In this respect, since the upper surface 92 of the elastomeric body 90 may also be used as an attachment surface, some deviation of the grasping position by the automatic mounting machine does not cause problems with respect to grasping.
[Second Embodiment]
The second embodiment uses an elastomeric body (the same type of material as in the first embodiment) having a side hole similar to the first embodiment; however, the configuration of the side hole is different from the first embodiment.
As illustrated in FIGS. 3A , and 3 B, and FIGS. 4A , 4 B, and 4 C, the configuration of a side hole 101 provided to an elastomeric body 100 of the second embodiment is substantially a trapezoid. The present embodiment is similar to the first embodiment except for primarily this point. Accordingly, the components with the same configurations are denoted with the same reference numerals as in the first embodiment, and a description of the same components may not be repeated.
As illustrated in FIGS. 3A and 3B , an elastomeric body 100 of the present embodiment comprises a side hole 101 . The side hole 101 is in the shape of approximately a trapezoid, and has openings at three places; two places facing the sides perpendicular to the side of the longitudinal hole 81 a connected to the supporting spring part 82 , and one place having an opening in the middle area of the longitudinal hole 81 a at the undersurface of the elastomeric body 100 .
The elastomeric body 100 comprises an upper surface 92 which is identical to the first embodiment. In the joint hole 94 , that is also the same as in the first embodiment, the elastomeric body 100 is connected to the supporting spring part 82 This contact member 70 is mounted on a printed circuit board 50 for use as in the first embodiment (refer to FIGS. 4B and 4C ). In FIGS. 4A , 4 B, and 4 C, the circuit pattern 51 and the solder paste 51 a disposed between the joint surface 81 b and the printed circuit board 50 are not shown in order to simplify the figures. After the contact member 70 is mounted on the surface of the printed circuit board 50 , the contact part 83 is pressed against a grounding conductor 60 , such as a housing or the like, by the closing of the housing accommodating the printed circuit board 50 (refer to FIGS. 4B and C).
The distance between the printed circuit board 50 and the grounding conductor 60 , interposing the contact member 70 therebetween, is set to be smaller than the height of the contact member 70 (measured from a joint surface 81 b to an upper surface of the contact part 83 ) when the contact member 70 is not subjected to an external force. Consequently, a pressing force from the grounding conductor 60 is applied to the contact part 83 .
As illustrated in FIG. 4B , because of this pressing force, the supporting spring part 82 is elastically deformed in such a manner that it collapses around a connecting part between the supporting spring part 82 and the base part 81 . Additionally, this pressing force acts upon the elastomeric body 100 either through the supporting spring part 82 and the contact part 83 , or directly, resulting in the elastic deformation of the elastomeric body 100 as if the elastomeric body 100 were crushed.
The pressing force applied to the contact part 83 acts upon the elastomeric body 100 as well, so that the elastomeric body 100 adds to the overall resistance and the result is that the contact member 70 is not excessively deformed. Therefore, even if the force to elastically deform the contact member 70 becomes excessive as in the situation above, the contact part 83 and the supporting spring part 82 can avoid being only plastically deformed and losing the spring characteristics.
When the elastomeric body 100 is elastically deformed in this manner, the side hole 101 becomes a deformation allowing space for the elastomeric body 100 . As a result, when the supporting spring part 82 is elastically deformed in a direction that brings the contact part 83 closer to the base part 81 , the resistance of the elastomeric body 100 is initially slight. In short, the effect to inhibit the plastic deformation of the parts is enhanced, because excessive force is applied to neither the supporting spring part 82 nor the contact part 83 .
Also, when the amount of elastic deformation of the contact member 70 is small (at an early stage of deformation by pressing) as illustrated in FIG. 4B , the existence of the side hole 101 facilitates the deformation of the elastomeric body 100 , thus allowing it to be deformed as shown in FIG. 4B with relatively little force. In this state, the end part of the contact part 83 engages the elastomeric body 100 , resulting in an elastic repulsive force being generated in the elastomeric body 100 and suppressing the excessive deformation of the contact member 70 .
When the amount of deformation is increased as illustrated in FIG. 4C , the side hole 101 is mostly contracted and the elastomeric body 100 starts shifting from elastic deformation to compressive deformation. This makes the elastic repulsive force of the elastomeric body 100 larger than initially in order to support the contact part 83 and the supporting spring part 82 . Consequently, the elastomeric body 100 inhibits these parts from being permanently deformed over the elastic limit; in other words, the effects of plastic deformation of the supporting spring part 82 and the contact part 83 are suppressed.
Although the elastomeric body 100 is disposed on the upper side of the base part 81 , the grounding conductor 60 , which elastically deforms the contact member 70 , firstly abuts the contact part 83 (and the upper face 92 of the elastomeric body 100 ). Therefore, the elastomeric body 100 does not disturb the electric contact between the grounding conductor 60 and the contact part 83 .
After the grounding conductor 60 is removed from the contact member 70 and the pressing force is released by the opening of the housing or the like, the elastomeric body 100 recovers elastically. Accordingly, even if the spring characteristics of the supporting spring part 82 , which is deformed by the pressure of the grounding conductor 60 , are lowered and the recovery ability of the spring part 82 is decreased, the elastomeric body 100 compensates for some of the lost spring characteristics and provides a sufficient recovery ability. For this reason, if the spring characteristics of the thin sheet member 80 are decreased (or lost), the contact part 83 can return sufficiently close to its original state. Therefore, for example, when the housing is opened and closed repeatedly, the contact between the contact member 70 and the grounding conductor 60 is maintained, inhibiting conductive failure.
Furthermore, as the elastomeric body 100 is attached to the supporting spring part 82 by having a part of the supporting spring part 82 penetrate into the joint hole 94 , there is no risk that elastomeric body 100 will be removed from the supporting spring part 82 (or, the thin sheet member 80 ) because of adhesion failure or the deterioration of an adhesive. There is no need to additionally adhere the elastomeric body 100 and the supporting spring part 82 with separate adhesive or the like, so it is possible to use hard-to-adhere materials for the elastomeric body 100 .
In the present embodiment, a configuration is adopted that the elastomeric body 100 is in contact with the contact part 83 and the base part 81 even in the state in which an eternal force, which would cause the contact member 70 to be elastically deformed, is not applied to the contact member 70 . Consequently, when the external force, which would result in the contact part 83 being elastically deformed in the direction of the base part 81 , is applied, the external force is immediately applied to the elastomeric body 100 as well.
However, such a configuration may also be adopted that the elastomeric body 100 is in contact with neither the contact part 83 nor the base part 81 in the state in which an external force, necessary to cause elastic deformation, is not applied to the contact member 70 . Only when the contact part 83 is displaced toward the base part 81 by more than a predetermined amount, the external force of the elastic deformation will be applied to the elastomeric body 100 as well. By using this configuration, for example, when the amount of displacement of the contact part 83 (and/or the amount of elastic deformation of the supporting spring part 82 ) is small, only the elastic repulsive force of the thin sheet member 80 maintains the abutting conduction between the contact part 83 and the grounding conductor 60 . Subsequently, the elastomeric body 100 primarily inhibits the amount of elastic deformation of the supporting spring part 82 that is excessive.
Furthermore, the upper surface of the contact part 83 in the present embodiment is flat. This surface becomes an attachment surface that can be grasped with an automatic mounting machine. This flat surface is grasped by the automatic mounting machine, allowing the contact member 70 to be mounted onto the printed circuit board 50 . In this situation, the upper surface 92 of the elastomeric body 100 may also become an attachment surface, so that some deviation of the grasping position by the automatic mounting machine does not result in problems.
[Third Embodiment]
The third embodiment uses an elastomeric body (with the same type of material as in the first embodiment) having a longitudinal hole. The components with the same configurations are denoted with the same reference numerals and the description of these components may not be repeated due to similarities and descriptions of the first embodiment.
As illustrated in FIGS. 5A , and 5 B, and FIGS. 6A , 6 B, and 6 C, an elastomeric body 110 of the third embodiment is provided with a cylindrically configured longitudinal hole 111 . The longitudinal hole 111 has a bottom opening in the area defined by the longitudinal hole 81 a. While the longitudinal hole 111 may have an open top and the top reaches the undersurface of the contact part 83 , in this embodiment the top of the longitudinal hole 111 is not opened thoroughly. About half of the diameter of the open top is covered by the flat upper surface 92 , which lies along the same plane as the upper surface of the contact part 83 .
The elastomeric body 110 is connected to the supporting spring part 82 by a joint hole 94 which is identical to the first embodiment. This contact member 70 is also mounted on a printed circuit board 50 for use as in the first embodiment (refer to FIG. 6B ). In FIGS. 6A , 6 B, and 6 C, the circuit pattern 51 and the solder paste 51 a disposed between the joint surface 81 b and the printed circuit board 50 are not shown in order to simplify the figures. For the contact member 70 mounted on the surface of a printed circuit board 50 in this manner, the contact part 83 is pressed against a grounding conductor 60 , such as a housing or the like, by the closing of the housing accommodating the printed circuit board 50 .
The distance between the printed circuit board 50 and the grounding conductor 60 , interposing the contact member 70 therebetween, is set to be smaller than the height of the contact member 70 (as measured from a joint surface 81 b to the upper surface of the contact part 83 ) when the contact member 70 is not subjected to an external force. Consequently, a pressing force from the grounding conductor 60 is applied to the contact part 83 .
As illustrated in FIG. 6B , because of this pressing force, the supporting spring part 82 is elastically deformed in such a manner that it collapses around a connecting part located between the supporting part 82 and a base part 81 . Additionally, this pressing force acts upon the elastomeric body 110 either through the supporting spring part 82 and the contact part 83 , or directly, resulting in elastic deformation of the elastomeric body 110 as it is crushed.
The pressing force applied to the contact part 83 acts upon the elastomeric body 110 as well, so that the elastomeric body 110 adds to the resistance and the contact member 70 is not excessively deformed. Therefore, even if the force to elastically deform the contact member 70 becomes excessive as described above, the result is avoided that the contact part 83 and the supporting spring part 82 are non-recoverably plastically deformed and that the spring characteristics of the parts are lost.
When the elastomeric body 110 is elastically deformed in this way, the longitudinal hole 111 becomes a deformation allowing space for the elastomeric body 110 . As a result, when the supporting spring part 82 is elastically deformed in the direction that makes the contact part 83 closer to the base part 81 , the resistance of the elastomeric body 110 is initially small. Consequently, the effect to inhibit plastic deformation is enhanced because excessive force is not applied to the supporting spring part 82 and the contact part 83 . Especially since the underside of the end part of the contact part 83 is positioned over the longitudinal hole 111 , thus preferably inhibiting excessive force being applied to the end part of the contact part 83 (i.e., potentially resulting in deformation of this part).
FIG. 6C shows the case in which an elastomeric body 120 , without the longitudinal hole 111 , is used for comparison. In this case, the repulsive force of the elastomeric body 120 is generated in the direction so that the contact part 83 is bent away or spread apart from the supporting spring part 82 . Thus, there is a risk that the bend forming the joint between the contact part 83 and the supporting spring part 82 is spread out and plastically deformed.
Although the elastomeric body 110 is disposed on the upper side of the base part 81 , the grounding conductor 60 , which elastically deforms the contact member 70 , firstly abuts the contact part 83 (and the uppersurface 92 of the elastomeric body 110 ). Therefore, the elastomeric body 110 does not disturb the electric contact formed between the grounding conductor 60 and the contact part 83 .
After the grounding conductor 60 is removed from the contact member 70 and the pressing force is released by the opening of the housing or the like, the elastomeric body 110 experiences an elastic recovery. Accordingly, even if the spring characteristic of the supporting spring part 82 , which is deformed by the pressure of the grounding conductor 60 , is lowered and the recovery ability is decreased, the elastomeric body 110 can compensate for some of the lost spring characteristics and provide a sufficient recovery ability. For this reason, even if the spring characteristic of the thin sheet member 80 is decreased (or lost), the contact part 83 can return sufficiently toward its original state. Therefore, for example, when the housing is opened and closed repeatedly, the contact between the contact member 70 and the grounding conductor 60 is maintained, thus inhibiting conductive failure.
Furthermore, as the elastomeric body 110 is attached to the supporting spring part 82 by using a part of the supporting spring part 82 penetrating into the joint hole 94 as a securing means, there is no risk that elastomeric body 110 is removed from the supporting spring part 82 (or, the thin sheet member 80 ) solely because of adhesion failure or the deterioration of an adhesive. It is not necessary to provide additional securing means between the elastomeric body 110 and the supporting spring part 82 , such as with an adhesive or the like, so it is possible to use hard-to-adhere materials for the elastomeric body 110 .
In the present embodiment, a configuration is adopted such that the elastomeric body 110 is in contact with the contact part 83 and the base part 81 even in an unstressed state. Consequently, when the external force, which causes the contact part 83 to be elastically deformed toward the base part 81 , is applied, it is immediately applied to the elastomeric body 110 as well.
A configuration may also be adopted such that the elastomeric body 110 is in contact with neither the contact part 83 nor the base part 81 in the state in which an external force able to cause elastic deformation is not applied to the contact member 70 . In this configuration, when the contact part 83 is displaced to the base part 81 by more than a predetermined amount, the external force of the elastic deformation is only then applied to the elastomeric body 110 as well. By doing this, for example, when the amount of displacement of the contact part 88 (and/or the amount of elastic deformation of the supporting spring part 82 ) is small, only the elastic repulsive force of the thin sheet member 80 maintains the abutting connection between the contact part 83 and the grounding conductor 60 . Subsequently, the elastomeric body 110 of this configuration only inhibits the amount of deformation of the supporting spring part 82 that is excessive.
Furthermore, the upper surface of the contact part 83 of the present embodiment is flat, which allows it to become an attachment surface that can be grasped with an automatic mounting machine. Therefore, this flat surface is subsequently grasped by the automatic mounting machine, allowing the contact member 70 to be mounted upon the printed circuit board 50 . On this occasion, as the upper surface 92 of the elastomeric body 110 may also become an attachment surface, small deviations of the grasping position with the automatic mounting machine does not cause any problems.
[Fourth Embodiment]
As illustrated in FIG. 7 and FIGS. 8A , 8 B, and 8 C, a contact member 1 is shown which comprises a thin sheet member 10 and an elastomeric body 40 .
A thin sheet member 10 is made up of plate metal (i.e., a material such as beryllium copper and phosphor bronze), and its thickness is in the range of 0.3 mm to 0.8 mm. Known press operations such as stamping out and bending are performed to the thin sheet member 10 . A base portion 11 , a supporting spring portion 21 , and a contact portion 31 are provided thereto.
The base part 11 is in an approximately rectangular shape, and includes a concave portion 11 b in a middle area of the base part 11 in its width direction. Both areas to the side of this concave portion 11 b are flat shaped and are referred to as joint surfaces 11 a. The joint surfaces 11 a are soldered onto a circuit pattern on a printed circuit board.
One end of the base part 11 is curved in an arc, while the other end is bent back in the direction opposing a joint surface 11 a, forming a U-shape. This bending part 11 c becomes a joint part with the supporting spring part 21 .
The entire supporting spring part 21 is an extremely gentle curve (the radius of curvature is relatively large). The supporting spring part 21 is bent in such a manner that the distance between the supporting spring part 21 and the base part 11 becomes greater as the supporting spring part 21 moves away from the bending part 11 c. The supporting spring part 21 is also bent in such a manner that the inclination of the supporting spring part 21 relative to the base part 11 becomes gentler as the supporting spring part 21 approaches its terminal part. An edge 21 b of the supporting spring part 21 is bent back in the direction of the base part 11 , substantially forming a semicircle.
Then, a middle area of the supporting spring part 21 in the width direction (i.e., the direction shown by X in FIG. 8A ) is cut and raised to form the contact part 31 . The contact part 31 has a width approximately equal to one-third of the total width of the supporting spring portion 21 and is disposed in the direction opposite to the base part 11 .
A contact part 31 comprises a connected part 31 a, which is connected to the terminal part of the supporting spring part 21 and inclined in a direction away from the base part 11 , a flat part 31 b which is bent down from the connected part 31 a and extends substantially parallel to the base part 11 (the joint surface 11 a ), and a free end part 31 c which is bent further down from the flat part 31 b and inclined in a direction toward the base part 11 . The connected area between the connected part 31 a and the supporting spring part 21 is referred to as a base end part α; the terminal of the free end part 31 c is referred to as a free end.
Also, by cutting and raising the contact part 31 , a substantially rectangular longitudinal hole 21 a is formed in the middle area of the supporting spring part 21 . The elastomeric body 40 is preferably a silicone elastomer which resists heating at 260° C. and has a cross section in the form of an elliptical bar like body. A deep slot 41 is provided to both end surfaces of the elastomeric body 40 as partially illustrated in FIG. 8C .
The elastomeric body 40 is disposed so as to be sandwiched between the base part 11 (the upper surface of the concave part 11 b ) and the contact part 31 (the under surface of the flat part 31 b ).
A part of the supporting spring part 21 enters the deep slot 41 of the elastomeric body 40 , thereby attaching the elastomeric body 40 to the supporting spring part 21 , i.e. the thin sheet member 10 . Also, the elastomeric body 40 is positioned directly under the contact part 31 ; however, the elastomeric body 40 is connected to neither the contact part 31 nor the base part 11 (it is not adhesively joined or the like).
This contact member 1 , as illustrated in FIG. 9A , is mounted on a printed circuit board 50 for use. More specifically, the contact member 1 is movably held by the upper surface (attachment surface) of the flat part 31 b being grasped by the vacuum suction of an automatic mounting machine. That contact member 1 is then disposed upon the printed circuit board 50 in such a manner that the joint surfaces 11 a are provided onto a solder paste 51 a on the printed circuit board 50 . The solder paste 51 a is subsequently melted by reflow soldering and cooled, thereby soldering the contact member 1 to the printed circuit board 50 .
In the contact member 1 mounted on the surface of the printed circuit board 50 in the aforementioned manner, the flat part 31 b is pressed against the grounding conductor 60 , for example a housing or the like, by the closing of the housing accommodating the printed circuit board 50 .
The distance between the printed circuit board 50 and the grounding conductor 60 , interposing the contact member 1 therebetween, is set to be smaller than the height of the contact member 1 when the contact member 1 is not subjected to an external force. Consequently, a pressing force from the grounding conductor 60 is applied to the flat part 31 b.
Because of this pressing force, the contact part 31 is elastically deformed around the base end part α, while the supporting spring part 21 is elastically deformed around the bending part 11 c. In this situation, the flat part 31 b is displaced while maintaining a substantially parallel relationship relative to the joint surfaces 11 a. Additionally, this pressing force acts upon the elastomeric body 40 as well through the contact part 31 , resulting in the elastic deformation of the elastomeric body 40 as if it were subject to a crushing type of force. FIG. 9A shows the state in which the contact part 31 , the supporting spring part 21 , and the elastomeric body 40 , are all elastically deformed using chain double-dashed lines.
FIG. 9B shows the state in which the elastomeric body 40 is not provided (illustrating with chain double-dashed lines the state in which the contact part 31 and the supporting spring part 21 are elastically deformed). In the case shown in FIG. 9A , unlike in the case shown in FIG. 9B , the pressing force applied to the contact part 31 acts upon the elastomeric body 40 as well, so that the elastomeric body 40 provides resistance and the contact member 1 is not excessively deformed. Therefore, even if the force to elastically deform the contact part 31 becomes excessive as shown above, the contact part 31 is inhibited from being plastically deformed and losing its spring characteristics.
The grounding conductor 60 , which contacts the contact part 31 and elastically deforms this, firstly abuts the contact part 31 (specifically the flat part 31 b ), because the elastomeric body 40 is sandwiched between the base part 11 and the contact part 31 . Therefore, the elastomeric body 40 does not disrupt the electric contact between the grounding conductor 60 and the contact part 31 .
After the grounding conductor 60 is removed from the flat part 31 b and the pressing force is released by the opening of the housing or the like, the elastomeric body 40 undergoes an elastic recovery. Accordingly, even if the spring characteristics of the contact part 31 , which is deformed by the pressure of the grounding conductor 60 , are reduced and the recovery ability is decreased, the elastomeric body 40 can compensate for the spring characteristics and provide a sufficient recovery ability. For this reason, if the spring characteristics of the contact part 31 are decreased (or lost), the contact part 31 can sufficiently return toward the original state. Therefore, for example, when the housing is frequently opened and closed, the contact between the contact member 1 and the grounding conductor 60 is maintained, inhibiting conductive failure.
Furthermore, there is no risk that elastomeric body 40 is unintentionally or accidentally removed from the supporting spring part 21 (i.e., the thin sheet member. 10 ) because of either adhesion failure or deterioration of an adhesive for example, because the elastomeric body 40 is attached to the supporting spring part 21 by causing a part of the supporting spring part 21 to penetrate the deep slot 41 within each end of the elastomeric body 40 . There is no need to supplemently adhere the elastomeric body 40 and the supporting spring part 21 with an adhesive or similar substance, so it is possible to use hard-to-adhere materials for the elastomeric body 40 .
Meanwhile, in the present embodiment, such a configuration is adopted that the elastomeric body 40 is in contact with the contact part 31 and the base part 11 even in the state in which the eternal force, which causes the contact part 31 to be elastically deformed in the direction of the base part 11 , is not applied to the contact member 1 . Consequently, when the external force is applied, it is immediately applied to the elastomeric body 40 as well.
Such a configuration may also be adopted that the elastomeric body 40 is in contact with neither the contact part 31 nor the base part 11 when the contact member 1 is unstressed, and that after the contact part 31 is elastically displaced in the direction of the base part 11 by more than a predetermined amount, the external force of the elastic deformation is applied to the elastomeric body 40 as well. For example, when the amount of elastic deformation of the contact part 31 is small, only the elastic repulsive force of the thin sheet member 10 maintains the abutting connection between the contact part 31 and the grounding conductor 60 . Subsequently, the elastomeric body 40 only inhibits when the elastic deformation of the contact part 31 becomes excessive.
In addition, the contact part 31 of the contact member 1 of the present embodiment is provided with the flat part 31 b which also functions as an attachment surface that can be grasped with an automatic mounting machine. Therefore, when the flat part 31 b is grasped by an automatic mounting machine, the contact member 1 can be mounted on the printed circuit 50 .
Further in addition, the flat part 31 b and the joint surface 11 a are approximately parallel to each other in the condition ill which the external force able to cause elastic deformation of the contact part 31 is not applied to the contact member 1 . Even when the contact part 31 is elastically deformed in a direction that makes the free end part 31 c approach the base part 11 , the flat part 31 b is able to maintain a substantially parallel relationship relative to the joint surface 11 a. Therefore, even when elastic deformation is caused by abutment onto a vacuum suction nozzle of the vacuum suction automatic mounting machine, gaps between the nozzle and the flat part 31 b are restrained. The grasp of the contact member 1 can be thereby performed effectively and the efficiency in the automatic mounting operation can be improved.
[Comparative Experiment]
The contact member 1 of the fourth embodiment and a contact member of a comparative example, which does not include the elastomeric body 40 and is only composed of the thin sheet member, are used for illustrative comparison. The comparison involves loading a contact part 31 (a flat part 31 b ) and measuring the recovery ability. The results are illustrated in FIG. 13A (the contact of the embodiment) and in FIG. 14A (the contact of the comparative example). FIG. 13B and FIG. 14B are graphs of loading (compressive force).
It is clear from the comparison between FIG. 13A and FIG. 14A that the contact member 1 of the embodiment has a higher recovery rate from compressive deformation.
[Modified Example of a Thin Sheet Member]
In the aforementioned fourth embodiment, the width of the middle area of a longitudinal hole 21 a in its longitudinal direction is substantially the same as the width of the flat part 31 b of a contact part 31 . As a modification of this, as illustrated in FIG. 10A , a supporting spring part 22 may be provided with a longitudinal hole 22 a having a width wider than that of the flat part 31 b of the contact part 31 .
Also, in the aforementioned fourth embodiment, the contact part 31 is formed by cutting and raising a portion of a supporting spring part 21 ; however, a contact part may also be formed as an extension of the supporting spring part and bent from the terminal part thereof. More particularly, as shown in FIG. 10B , a contact part 33 may be formed by bending an extension back from an end part 23 b of a supporting spring part 23 in the direction opposite to a base part 13 . Alternatively, as shown in FIG. 10C , an end 24 b of a supporting spring part 24 may be bent around in the direction of a base part 14 , thereby forming a contact part 34 , which has a connected part 34 a penetrating through a longitudinal hole 24 a of the supporting spring part 24 .
[Modified Example of an Elastomeric Body]
In the above described fourth embodiment, an elastomeric body 40 whose cross section is approximately elliptical is used; however, the cross section thereof maybe circular ( FIG. 11A ), oval ( FIG. 11B ), square or rectangular ( FIG. 11C ), and polygonal ( FIG. 11( d )) or a combination of any of the above.
Also, as shown in FIG. 12 , it is possible to adopt such a configuration that approximately the whole space inside of the thin sheet member 10 may be filled with an elastomeric body 40 (hatching is performed for clarification).
All of the embodiments described may be used without separate fastening or adhering techniques. But this does not imply that the use of such techniques is prohibited within the scope of this invention, but only implies that they are not required.
In addition, specific types of material, shapes and/or configurations were described in an attempt to enable the embodiments of the invention. The scope of this invention includes combinations of geometric figures described as well as all obvious variations thereof, including but not limited to, the use of material with multiple densities and spring rates, conductive materials, cavities, holes, and other variations known or accepted by people skilled in the art.
The invention is not restricted to the embodiment as described above, and may be practiced or embodied in still other ways without departing from the subject matter thereof. | A contact member formed with a flat metal structure and an integrated elastomeric body. The contact member can be used to ground a printed circuit board (PCB) with a surrounding housing. The housing loads the contact member in a direction perpendicular to the face of the PCB. The elastomeric body supports the flat metal structure during repeated cycles of loading and unloading of the contact member. The elastic resiliency of the elastomeric body can help to reduce the effects of plastic deformation of the contact member, resulting in more reliable electrical connections a source outside of the PCB. And the elastomeric body does not require adhesive or separate fixing devices to hold it in place. | 7 |
This application is a continuation-in-part of application Ser. No. 07/977,859, filed 17 Nov., 1992.
FIELD OF THE INVENTION
This invention relates to building materials and particularly stackable blocks. More specifically, the invention includes designs for building blocks which may be collapsed for storage. Such blocks are particularly suited as toys for children, but industrial applications exist for the invention as well.
BACKGROUND OF THE INVENTION
Building blocks which are hollow have been disclosed previously. An example is described in the U.S. Pat. No. 5,035,098 to Newsom. In the Newsom patent, molded containers for liquids are made in a shape which allows them to be assembled in a nested fashion to form a wall. It is contemplated that these containers be used to construct wall-forms after they have served as containers to transport fluids, and have been emptied. The Newsome containers are described throughout as being rigid and are not collapsible in any way.
A reference that has issued for a collapsible building element is U.S. Pat. No. 2,990,837 to Cushman. This document describes an air inflated wall structure that may be erected to form a large circular enclosure. Periodically placed internal panels, placed transversely within side walls, constrain the shape of the inflated structure to form the walls of the enclosure. A bottom tube is filled with water in order to provide ballast for the structure.
Other inflated structures are described in the following references:
U.S. Pat. No. 3,432,609 to Duvall
U.S. Pat. No. 4,556,391 to Tardivel et al
U.S. Pat. No. 5,236,261 to Wilbourn et al
None of these references, however, describe a stackable building block which may be inflated to form a stable structure. It is with the objective of providing such a product that this invention has been conceived.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification.
SUMMARY OF THE INVENTION
In its more general sense the invention comprises a hollow, air-tight, modular, stackable building block for constructing a structure having corrugated or pleating sides which will collapse, and a sealable orifice whereby a fluid filling such as water, air or free-flowing sand may be introduced into and out of the interior cavity formed within the modular building block in order to maintain its shape.
The top and bottom faces of the block are preferably made relatively rigid, as compared to the sides. Such faces are preferably generally horizontally oriented and are provided with complementary connector or coupling means, such as protrusions and depressions formed on the respective top and bottom faces, whereby the blocks can be laid in interfitted courses to form a more stable structure. Ideally, the protrusions and depressions are positioned so that the blocks may be staggered to increase their interlocking strength. Additionally, the protrusions and depressions are preferably positioned to permit construction of walls having corners, and angular deflections from the shape of a simple plane structure. This may include both fixed 90 degree deflections and a range of other deflections extending upwards from zero degrees.
The sides of the block are intended to be collapsible. They may be formed from thin-walled, pleated sheeting. In the pleated format the blocks may be collapsed and expanded in an accordion-like manner.
A preferred manner for fabricating the blocks of the invention is by blow-molding. However, other known suitable fabrication means may alternately be employed.
The foregoing summarizes the principal features of the invention and some of its optional aspects. The invention may be further understood by the description of the preferred embodiments, in conjunction with the drawings, which now follow.
SUMMARY OF THE FIGURES
In drawings which illustrate the embodiments of the invention:
FIG. 1 is a perspective view of an embodiment of the invention with pleated side faces.
FIG. 2 is a cut-away end view of the pleated embodiment of FIG. 1 in fully erect, inflated form.
FIG. 3 is a partial end view of the pleated side wall of the block of FIG. 2, with the block partially collapsed.
FIG. 4 is a perspective view of the bottom of a cross-sectioned block as in FIGS. 1-3.
FIG. 5 is a detailed cross-section of the receptacle depressions formed in the bottom of the block of FIG. 4.
FIG. 6 is a face view of the block of FIG. 1 showing four coupling posts positioned on the top of the block.
FIG. 7 is a top view of FIG. 6.
FIG. 8 is a bottom view of the block of FIGS. 1 and 7.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a perspective view of a block with pleated accordion-like sides. The block 50 has relatively flat top 51 and bottom 52 faces with outwardly directed exterior surfaces in the form of panels which are sufficiently thick to be relatively stiff. The encircling sides 53 delimiting the boundaries of the top 51 and bottom 52 faces have end 54 and face portions 55 which are pleated in an accordion-like manner to permit folding and compression of the sides 53, and thereby to provide for the collapse of the block, as shown in FIG. 3.
This block 50 is preferably blow-molded from polyethylene or polypropylene plastic, with a side-wall thickness on the order of 1 millimetre and preferably a thickness of 1-3 mm in the top 51 and bottom 52 panels. Inset ribs 56 may optionally traverse the top 51 and/or bottom 52 panels to increase stiffness. Further stiffening may be provided by additional ribs.
Preferred dimensions for the block are 24 to 30 cm long by 12 to 15 cm wide and by 12 to 15 cm high. However, the size of the blocks is not restricted to any specific specifications, and may be changed according to the purpose. The same applies in relation to the shape of the block, and the blocks can be made in the shape of half-blocks or trapezoidal shapes.
Protrusions 57 extend upwardly from the top panel 51 and are intended to inter-engage in sockets 65 in the bottom panel 52 and serve as attachment or coupling means. A preferred configuration for the protrusions 57 is to have a single row, centered on the longitudinal middle or median line 59 within the longitudinal median plane of the block 50 and symmetrically disposed about the transverse middle or median line 58 within the transverse median plane of the block 50.
Top and bottom faces 6, 8 may each contain two complimenatry VELCRO (TM) -type pads 14 as a means to attach completed blocks together to form a stacked structure.
In FIG. 2 a profile end view of the block 50 shows that the protrusion 57 may have a tapered upper edge or shoulder 60 and a lip 61 to assist in assembly and in providing positive attachment.
In FIGS. 4 and 5 the lower panel 52 with its complementary sockets 65 is depicted. The sockets 65 each have a tapered socket shoulder 63 over which the ends 62 of the protrusions 57 may slide as an alignment guide during assembly. Grooves 64 at the perimeter of the socket shoulder 63 engage the lips 61. These grooves 64 are shown as being provided with a circular rim 72. This rim 72 may be interrupted to form a series of protruding lugs 73 shown in one example in FIG. 8. Such lugs 73 will expand and release more readily than a continuous rim.
A sealable orifice in the form of valve well 66 is provided with a preferably self-closing valve 67 at its end, although a manually sealable orifice may also be employed. This valve may be opened, as by a pencil or finger, to allow air or other flowable substance to enter or escape from the block.
As shown in FIGS. 2 and 6 (only), the sides 53 of the block 50 are optionally provided with notches 68 along the perimeter of the bottom panel 52 to receive fingers during separation and disassembly of the blocks. These, as shown in FIGS. 4 and 6, may be positioned opposite sockets 65. The ribs 56, in the form of a depressed groove, as shown in FIG. 1, preferably extend to the outer edge of the block 50 where they can be seen. By locating the ribs 56 at regularly spaced intervals, their outer ends serve as alignment guides for fitting the protrusions 57 into the receptacles 65.
The sockets 65 may be laid-out in a multiple, overlapping cross-format, best seen in FIG. 8. This pattern of sockets 65 allows the blocks to be oriented at 90 degrees, if two sockets 65a, 65b are engaged by protrusions 57; or to swing over a range of degrees if a end socket 65c only is engaged by a single end protrusion 57. This range of motion is limited by interference between the first unengaged protrusion 57a and the top face 51. This allows for more complex structures to be formed than that of a simple, planar wall.
While the blocks of FIG. 2 and 6 are intended to be stacked to form a wall structure having staggered, inter-engaged, over-lying courses with the pleated sides 93 forming the vertical sides, such blocks may also be stacked with the pleated sides 53 forming the top and bottom faces of the block.
Blocks according to the invention are suited to be stacked up by children to construct larger toy play structures than traditional sized blocks, optionally large enough to walk-into. They may also be used to create functional structures that benefit from the insulating qualities of air-filled blocks. Blocks of the invention may also be filled with water, sand or other flowing materials for such applications as flood or military use.
The blocks enjoy the advantage of being light and compact to store and transport. If made of polymer plastic, they are generally weather-proof. A further advantage is that when produced on a mass basis, such blocks should be relatively inexpensive.
Conclusion
The foregoing has constituted a description of specific embodiments showing how the invention may be applied and put into use. These embodiments are only exemplary. The invention in its broadest, and more specific aspects is further described and defined in the claims which now follow.
These claims and the language used therein, are to be understood in terms of the variants of the invention which have been described. They are not to be restricted to such variants, but are to be read as covering the full scope of the invention as is implicit within the invention and the disclosure that has been provided herein. | An inflatable building block is provided with collapsible sides. Coupling means on the upper and lower faces allow the blocks to be interconnected to form structures. A preferred format relies on pleated sides that will collapse in an accordion-like fashion. | 4 |
RELATED APPLICATION
This is a divisional of U.S. patent application Ser. No. 12/381,971, filed 18 Mar. 2009, now U.S. Pat. No. 8,726,468.
BACKGROUND OF THE INVENTION
The present invention is directed generally to bundle ties, and more specifically to a bundle tie having an improved bundle-engaging surface.
Bundle ties, sometimes referred to as cable ties, are generally well known in the art. A typical bundle tie includes a relatively flat strap having a free first end and a tie head coupled to a second end. The tie head generally includes a strap engaging means, which may be provided as an aperture through the tie head and a locking pawl situated on or within the head, the pawl adapted to engage one or more serrations provided on an engaging surface of the strap. When the strap is inserted into the aperture in the tie head and the pawl engages the serrations, the tie generally forms a tie loop.
Prior tie heads have been coupled to a tie strap generally in two orientations: first, normal entry tie heads include an aperture through the tie head that is formed substantially perpendicular to the strap in its formed, at-rest state; and second, parallel entry tie heads include an aperture through the tie head that is formed substantially parallel to the strap in its formed, at-rest state. Further, parallel entry tie heads have been provided at various angles relative to the tie straps. Regardless of the manner in which a tie head is oriented on a tie, it has been observed that certain forces imparted by a tie head onto the bundle being secured may be damaging to the bundle.
Additionally, prior ties have generally been formed out of a relatively strong, yet flexible material, such as plastic, nylon, stainless steel, etc. Many elongate articles in conjunction with which bundle ties are used have a smooth, flexible coating. Thus, it has been noticed that a bundle that was secured by prior devices may be inclined to slip through the loop formed by a prior fastened tie.
Therefore, the art of bundle ties would benefit from a bundle tie having a head dampener to assist in preventing damages to a tied bundle and further to assist in preventing an elongate article, or a plurality of elongate articles, from sliding within a bundle tie loop.
SUMMARY OF THE INVENTION
A device according to the present invention provides a bundle tie having a head dampener to assist in preventing damages to a tied bundle and further to assist in preventing an elongate article, or a plurality of elongate articles, from sliding within a bundle tie loop.
A bundle tie having a head dampener according to the present invention includes an elongate strap, a tie head coupled to the elongate strap and a head dampener provided on at least a portion of the tie head. The head dampener is preferably at least partially comprised of a material that is different than at least part of the tie head. The tie head may include a first head end and a second head end coupled to the strap. The head further includes a head outer surface and a head bundle surface, which is generally opposed from the head outer surface. Extending between the head outer surface and the head bundle surface, from the first head end towards the second head end, is at least one lateral head side. The head dampener is provided on at least a portion of the tie head, such as on a portion of the head bundle surface.
According to an aspect of a bundle tie according to the present invention, the elongate strap generally includes a first strap end, a second strap end, a strap outer surface and a strap bundle surface generally opposed from the strap outer surface. Extending between the strap outer surface and the strap bundle surface is at least one lateral strap side. The strap outer surface, bundle surface and lateral strap sides form a substantially flat strap body extending between and including the first strap end and the second strap end.
According to an aspect of a bundle tie according to the present invention, the tie head may be coupled to the strap by being formed integrally therewith.
According to an aspect of a bundle tie according to the present invention, an aperture may extend through the tie head, the aperture being adapted to receive at least a portion of the strap. The aperture may extend through the head outer surface and the head bundle surface, or the aperture may extend between the head outer surface and the head bundle surface.
According to an aspect of a bundle tie according to the present invention, a head dampener comprising first and second intersecting nonintersecting dampening rails may be disposed on the head bundle surface. Each of the dampening rails may be positioned closer to one or the other of the lateral head sides.
According to an aspect of a bundle tie according to the present invention, a head dampener may extend onto a portion of the strap, such as the strap bundle surface. The head dampener may extend onto the strap for a desired length, which may include at least a majority of the length of the strap. Where dampening rails are provided as a head dampener, each rail may extend onto the strap along at least substantially similar lengths.
According to an aspect of a bundle tie according to the present invention, the aperture formed through the tie head may extend between the head outer surface and the head bundle surface, through the first head end, at least substantially parallel to a portion of the head bundle surface. The aperture may further include two spaced longitudinal, at least substantially parallel rail channels, each rail channel being in fluid communication with the first head end. Each rail channel may be positioned closer to the head bundle surface than to the head outer surface.
According to an aspect of a bundle tie according to the present invention, a head dampener comprising a dampening film may be disposed on at least a portion of the head bundle surface, or even a majority of the head bundle surface.
According to an aspect of a bundle tie according to the present invention, a dampening film that is disposed on the head bundle surface may extend onto the strap, such as the strap bundle surface, along a predetermined strap film length.
A method according to the present invention of forming a bundle tie having a head dampener includes the steps of providing a tie mold having a bundle tie head cavity and a bundle tie strap cavity, and injecting a first material into the tie mold. The first material is held in the tie mold for a first curing time, thereby creating a bundle tie. The tie head cavity may be modified to create a modified bundle tie head cavity, thereby providing a cavity for forming a head dampener. A second material is injected into the modified bundle tie head cavity. The first and second materials are then held for a second curing time, thereby creating a bundle tie having a head dampener. The bundle tie having a head dampener is then removed from the tie mold.
According to an aspect of a method according to the present invention of forming a bundle tie having a head dampener, such method may include the step of maintaining the bundle tie within the tie mold during the modification of the tie head cavity.
According to an aspect of a method according to the present invention of forming a bundle tie having a head dampener, such method may include removing the bundle tie from the tie mold prior to modifying the tie head cavity, and placing at least a portion of the bundle tie in the modified tie mold prior to injecting the second material into the modified tie mold.
According to an aspect of a method according to the present invention of forming a bundle tie having a head dampener, such method may include a step of modifying the tie strap cavity.
Another method according to the present invention of forming a bundle tie having a head dampener includes the steps of providing a first tie mold having a bundle tie head cavity and a bundle tie strap cavity, and injecting a first material into the first tie mold. The first material is held in the tie mold for a first curing time, thereby creating a bundle tie. The bundle tie is then removed from the first tie mold and placed in a second tie mold having a bundle tie cavity and a head dampener cavity. A second material is injected into the second tie mold to at least substantially fill the head dampener cavity. The first material and the second material are held in the second tie mold for a second curing time, thereby creating a bundle tie having a head dampener. The bundle tie having a head dampener is then removed from the tie mold. Rather than injecting a second material into a modified tie mold, the second material could simply be applied directly to the bundle tie. For example, a pattern of a second material may be disposed on the cured first material. Such pattern may be, for example, a pair of intersecting or nonintersecting beads or rails, or a dampening film.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a first embodiment of a bundle tie according to the present invention, in a flexed position to show detail.
FIG. 1B is a perspective view of a portion of the embodiment of FIG. 1A , having a head dampener extending onto a portion of the tie strap.
FIG. 1C is an elevation view of the bundle tie of FIG. 1B installed around a bundle.
FIG. 1D is a to plan partial cut away view of the embodiment of FIG. 1B further comprising rail clearance channels.
FIG. 1E is an elevation view of the bundle tie of FIG. 1D installed around a bundle.
FIG. 1F is a perspective partial cut away view of the embodiment of FIG. 1B , further comprising enhanced head dampening rails.
FIG. 1G is a perspective partial cut away view of a plurality of ties according to the embodiment of FIG. 1F an open loop configuration.
FIG. 1H is a perspective view of a portion of the embodiment of FIG. 1B , having a shortened head dampener.
FIG. 2A is a perspective view of a second embodiment of a bundle tie according to the present invention.
FIG. 2B is a perspective view of the embodiment of FIG. 2A , having an extended head dampener.
FIG. 3 is a perspective view of a third embodiment of a bundle tie according to the present invention.
FIG. 4A is a perspective view of a fourth embodiment of a bundle tie according to the present invention.
FIG. 4B is a perspective view of the embodiment of FIG. 4A , having an extended head dampener.
FIG. 5A is a perspective partial cut away view of a fifth embodiment of a bundle tie according to the present invention.
FIG. 5B is a perspective partial cut away view of the embodiment of FIG. 5A , wherein the dampening rails intersect.
FIG. 5C is a perspective partial out away view of a sixth embodiment of a bundle tie according to the present invention.
FIG. 5D is a perspective partial cut away view of a seventh embodiment of a bundle tie according to the present invention.
FIG. 6A is a first cross-section view of a first tie mold that may be implemented in a method according to the present invention.
FIG. 6B is a second cross-section view of the first tie mold of FIG. 6A .
FIG. 6C is a third cross-section view of the first tie mold of FIG. 6A , showing the insert removed.
FIG. 7A is a first cross-section view of a second tie mold that may be used in a method according to the present invention.
FIG. 7B is a first cross-section view of a third tie mold that may be used in a method according to the present invention.
FIG. 7C is a second cross-section view of the third tie mold of FIG. 7B .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
Turning now to the Figures, FIG. 1A provides a first embodiment 100 of a bundle tie according to the present invention. The tie 100 generally comprises a substantially flat tie strap 110 having a strap outer surface 112 and a strap bundle surface 114 generally opposed from the strap outer surface 112 , extending between a first strap end 116 and a second strap end 118 . The tie strap 110 includes two lateral strap edges 120 , each edge being situated preferably substantially parallel to and equidistant from a central longitudinal axis 122 , preferably along at least a majority of the length 111 of the strap 110 . At least a portion of the strap 110 is provided with an engagement means 113 , such as a plurality of serrations 115 provided on or formed into the strap outer surface 112 or the strap bundle surface 114 .
The tie 100 further comprises a tie head 150 counted to the second strap end 118 . The tie head 150 is preferably coupled to the second strap end 118 by being integrally formed therewith. The tie head 150 includes a head outer surface 152 and a head bundle surface 154 generally opposed from the head outer surface 152 , extending between a first head end 156 and a second head end 158 . The tie head 150 includes two lateral head sides 160 , each side being preferably situated substantially equidistant from the central longitudinal axis 122 . Formed between the lateral head sides 160 is a throughbore 151 adapted to receive the first strap end 116 . As shown, the throughbore 151 may also be formed between the outer surface 152 and the bundle surface 154 . Alternatively, the throughbore 151 may be formed through the outer surface 152 and the bundle surface 154 , between the lateral head sides 160 . The tie head 150 also includes a second engagement means 153 , such as a pawl 155 , for cooperating with the first engagement means 113 provided on the strap 110 . The second engagement means 153 is preferably at least partially situated within the throughbore 151 . The head bundle surface 154 extends preferably at least substantially between the two lateral head sides 160 , which may be extensions of the lateral strap edges 120 , and preferably at least substantially between the first head end 156 and the second head end 158 . The head 150 may include a perforate transition section 157 , including a non-strap-engaging aperture formed through the head 150 , perpendicular to the head bundle surface 154 . The head bundle surface 154 is provided with a head dampener 162 .
The head dampener 162 may be formed in a variety of fashions. In this first embodiment 100 , the head dampener 162 is a pair of non-intersecting dampening rails 164 . While provided as preferably non-intersecting rails 164 , it will occur to those in the art that the rails 164 may also be provided as intersecting, as exemplarily discussed below in connection with FIGS. 5B and 5D . While provided at least on the head bundle surface 154 , the rails 164 may extend onto the strap bundle surface 114 for a desired rail length 166 , as seen in FIG. 1B , the length of which may be a correlated to the planned use for the tie 100 . In other words, the length 166 of the dampening rails 164 that extends onto the strap bundle surface 114 may be tailored to result in an overall head dampener length 168 substantially similar to the expected resulting circumference of the tie 100 when it is placed around a predetermined bundle 190 of elongate articles 192 , as shown in FIG. 1C . For instance, the dampening rail length 166 may be provided in lengths ranging from about 0.25 inches to about two inches, more preferably ranging from about 0.50 inches to about 1.50 inches. Additionally, a predetermined selection of bundle ties 100 having different dampening rail lengths 166 may be provided in a kit form, thereby providing a user selection. The dampening rails 164 may be provided in any functional thickness 170 , disposed on the head bundle surface 154 . The dampening rail thickness 170 is preferably in the range of about 0.020 inches to about 0.100 inches, and more preferably the thickness 170 is about 0.039 inches.
While the preferred tie head 150 is shown as a parallel entry tie head that may be formed generally perpendicular to the strap 110 , in its at-rest state, any preferred tie head 150 may be used. The at-rest state of the tie 100 is to be understood to mean any resting position adopted by the tie 100 from completion of manufacturing until the final installation of the tie 100 about a bundle. For example, a tie 100 placed upon a level table and being exposed only to the force upon the tie 100 by the table and ether ambient environmental forces is a tie 100 in an at-rest state.
As shown in FIG. 1D and FIG. 1E , if the head dampener 162 is provided along a length 166 on the tie strap 112 , and the strap 112 is to be fastened around a bundle 190 that has a general annular circumference that is less than the overall head dampener length 168 , or if the dampener 162 is provided along the entire length of the lateral strap edges 120 , then it is preferable to provide clearance for the dampener 162 while maintaining adequate engagement means support to oppose any lateral force exerted by the pawl 155 . Dampener clearance may be provided by rail clearance channels 159 formed as radial extensions of the head throughbore 151 . The clearance channels 159 , of which there are preferably the same number as there are rails 164 , are formed at a depth 172 that is preferably at least as great as the rail thickness 170 . Alternatively, the rail, channel depth 172 may be less than the rail thickness 170 , preferably so long as an operative throughbore depth 174 is at least as great as an operative strap depth 176 . Alternatively, the operative throughbore depth 174 may be slightly less than the operative strap thickness 176 , which may cause a frictional engagement of the clearance channels 159 with the rails 164 .
FIG. 1F depicts the embodiment of FIG. 1D , further comprising expanded head rail portions 164 a . The expanded head rail portions 164 a provide a greater rail thickness 170 , and preferably width, also. Such expanded rail volume may provide altered rail resiliency characteristics, as well as a greater rail surface area, which may be desirable for some applications. Additionally, the perforate transit ion section 157 of FIG. 1D has been substituted by an imperforate transition section 161 .
FIG. 1G depicts two bundle ties according to the embodiment of FIG. 1F , joined to term a partially open loop. That is, the strap 110 of a second bundle tie 100 b has been inserted through the throughbore 151 of a first bundle tie 100 a , and excess strap length 165 has been trimmed off. The first engagement means 113 of the second tie 100 b has been engaged by the second engagement means 153 of the first tie 100 a , to resist withdrawal from the throughbore 151 . Such a looping arrangement may be desirable if the overall head dampener length 168 of one tie 100 , such as the first tie 100 a , is less than the general annular circumference of the bundle 190 to be secured. Therefore, the addition of the second tie 100 b serves to increase, effectively, the overall head dampener length 168 of a single tie 100 . While the arrangement may be achieved generally with any embodiment of the present invention, it may be preferable to utilize two ties 100 having the expanded head rail portions 164 a so as to minimize pressure of the leading bundle surface edge 163 of at least one of the ties, in the pictured case, the first tie 100 a . As can also be seen in FIG. 10 , a transition portion 167 of the tie head 150 may be thinner than the rest of the strap 110 , as measured perpendicular to the bundle surface 154 .
FIG. 1H displays an alternate first embodiment 100 , having the head dampener 162 extending from the head second end 158 towards the head first end 156 , along less than a majority of the head bundle surface 154 . Optionally, the dampener 162 , provided in this embodiment as a pair of dampening rails 164 , may extend onto the strap bundle surface 114 for a desired rail length 166 .
FIG. 2A displays a second embodiment 200 of a bundle tie according to the present invention, where like reference numbers refer to similar structure to that of the first embodiment. Like the first embodiment 100 , this embodiment 200 is provided with a head dampener 262 . Rather than providing the dampening rails 164 , as in the first embodiment 100 , this embodiment 200 utilizes a dampening film 264 . The dampening film 264 is preferably provided in a substantially uniform thickness across at least substantially the entire head bundle surface 254 . While provided at least on a portion of the head bundle surface 254 , the film 264 may extend onto the strap bundle surface 214 for a desired film length 266 , as seen in FIG. 2B , the length of which may be a related to the planned use for the tie 200 . For instance, the dampening film length 266 may be provided in lengths ranging from about 0.25 inches to about two inches, more preferably ranging from about 0.50 inches to about 1.50 inches. Additionally, a predetermined selection of bundle ties 200 having different dampening film lengths 266 may be provided in a kit, form, thereby providing a user selection. The dampening film 264 may be provided in any functional thickness 270 , disposed on the head bundle surface 254 .
FIG. 3 displays a third embodiment 300 of a bundle tie according to the present invention, where like reference numbers refer to similar structure to that of the second embodiment 200 . Like the second embodiment 200 , this embodiment 300 includes a head dampener 362 in the form of a dampening film 364 . However, this embodiment 300 includes the film 364 on only a portion of the head bundle surface 354 , not substantially the entire head bundle surface 354 , like the film 264 of the second embodiment 200 .
FIG. 4A displays a fourth embodiment 400 of a bundle tie according to the present invention, where like reference numbers refer to similar structure to that of the third embodiment. This embodiment 400 , like the third embodiment 300 , includes a dampening film 464 on only a portion of the head bundle surface 454 . However, the dampening film 464 extends from the head second end 458 , and may extend onto the strap bundle surface 414 for a predetermined length 466 , as seen in FIG. 4B .
FIG. 5A depicts a fifth embodiment 500 of a bundle tie according to the present invention, where like reference numbers refer to similar structure to that of the first embodiment. Unlike the perforate transition portion 157 of the first embodiment, this embodiment includes an imperforate transition portion 561 .
FIG. 5B depicts an alternate fifth embodiment 500 of a bundle tie according to the present invention, where like reference numbers refer to similar structure to that of the first embodiment 100 . Unlike the separate and distinct rails 564 provided in FIG. 5A , this alternate embodiment provides a pair of intersecting dampening rails 564 . The rails 564 generally intersect to form a V-shape head dampener 562 , which may include a first length 562 a along which the dampening rails 564 are at least substantially parallel, and a second length 562 b , along which the dampening rails 564 converge.
FIG. 5C is a perspective, partial cut away view of a sixth embodiment 600 of a bundle tie according to the present invention, where like reference numbers refer to similar structure to that of the embodiment of FIG. 2A . Unlike the perforate transition portion 257 of the first embodiment, this embodiment includes an imperforate transition portion 661 .
FIG. 5D is a perspective partial cut away view of a seventh embodiment 700 of a bundle tie according to the present invention, where like reference numbers refer to similar structure to that of the sixth embodiment 600 . The head dampener 762 of this embodiment 700 includes at least two, and preferably three, components. First, a dampening film 764 a is provided. Second, dampening rails 764 b are provided. Additionally, a dampening sleeve 764 c may also be provided. While these dampener components may be provided as separate and distinct components, it is preferable to provide the components as molded integrally together, and of the same material. The dampening film 764 a is disposed directly on the head bundle surface 754 , covering at least a majority thereof. The dampening rails 764 b are disposed on top of or adjacent to the dampening film 764 a . The rails 764 b are preferably provided as intersecting rails, as shown, similar to the rails of the alternate fifth embodiment 500 of FIG. 5B . Alternatively, the rails 764 b may be provided as nonintersecting rails, similar to those of the fifth embodiment 500 of FIG. 5A . The dampening sleeve 764 c is a band of material that encircles the remainder of a circumference of the tie head 750 formed by the head bundle surface 754 , the head lateral sides 760 and the head outer surface 752 . Rather than being molded onto the tie head 750 , a dampener 762 including the dampener sleeve 764 c may be provided as a separate piece part, to be friction fitted to the head 750 . The transition section 761 of the tie head 750 of this embodiment 700 is preferably imperforate.
Bundle ties according to the present invention are preferably injection molded and formed from a strong, yet flexible material such as various plastics, nylon, and the like. The dampening rails and films of the disclosed embodiments may be formed from any desirable material. A preferred elastomeric material may be used, such as a silicone elastomer. Other possible dampener materials include thermoplastic elastomers (TPE), such as thermoplastic vulcanizates (TPV) and thermoplastic styrenics (TPS), thermoplastic olefin (TPO), and thermoplastic urethane (TPU). While the head dampeners of the various embodiments may be adhered to the tie heads and straps after manufacture, the ties are preferably made by using a multi-material molding process, such as a multi-shot injection molding process where the tie is molded first, the injection molding cavity of the tie mold is altered or the tie is moved to a second tie mold, and the elastomeric material is injected to bond to at least a portion of the head and form the desired head dampener.
FIGS. 6A, 6B, and 6C depict steps included in a first process for manufacturing a bundle tie according to the present invention. FIG. 6A shows a two-piece tie mold 800 with a removable insert 802 . When first assembled, as shown in FIG. 6B , the mold 800 provides a bundle tie head cavity 804 in fluid communication with a bundle tie strap cavity 806 . The insert 802 interfaces at least a portion of the tie head cavity 804 . A first material is injected into the tie meld 800 . The first material is held for a first curing time, allowing the material to cure to a sufficient or desired hardness, thereby forming a bundle tie head 150 coupled to a bundle tie strap 110 . The mold 800 is then modified by removing the mold insert 802 , thereby creating a modified bundle tie head cavity 808 . If the coupled molded tie head 150 and strap 110 were removed from the mold 800 to remove the insert 802 , it is replaced into the mold 800 , as shown in FIG. 6C . A second material is injected into the modified bundle tie head cavity 808 . To create a bundle tie having a head dampener, the first material and second material are held in the mold 800 for a second curing time, which may be shorter the same as, or longer than the first curing time, depending on materials used. A completed bundle tie, e.g. the tie 100 in FIG. 1B , is then removed from the mold 800 .
FIGS. 7A, 7B, and 7C depict steps included in a second process for manufacturing a bundle tie according to the present invention. In this process, a plurality of molds is used in series to successively mold different portions of a completed bundle tie. FIG. 7A provides a first tie mold 900 having a bundle tie head cavity 902 and a bundle tie strap cavity 904 . A first material in injected into the first tie mold 900 and held for a first curing time, thereby creating a bundle tie having a head 150 coupled to a strap 110 . The bundle tie is removed from the first tie mold 900 and is placed into a second tie mold 950 , as shown in FIG. 7B . The second tie mold 950 has a bundle tie cavity, in which the bundle tie is situated, and a cooperating head dampener cavity 906 , which interfaces at least a portion of the bundle tie head 150 , when a bundle tie is placed in the second mold 950 . A second material is injected into the second tie mold 950 to at least substantially fill the head dampener cavity 906 . A bundle tie having a head dampener is then formed by holding the bundle tie and second material in the second tie mold 950 for a second curing time, which may be shorter, the same as, or longer than the first curing time. A completed bundle tie, e.g. tie 100 in FIG. 1B , is then removed from the second tie mold 950 . One advantage of using a two mold process, as partially illustrated in FIGS. 7A-7C , is that a second bundle tie may be formed contemporaneously with the forming of a head dampener on the first tie. That is, once a first tie is removed from the first tie mold 900 and placed lathe second tie mold 950 to form the head dampener on the first tie, the first tie mold 900 may be used to form a second bundle tie.
The method partially depleted in FIGS. 7A-7C may be changed without departing from the invention. For instance, rather than removing the tie from a first mold 900 and placing it in a second mold. 950 , the tie may remain in a strap mold base 910 , and may be associated with a dampening mold 930 . Thus, the second mold 950 would be formed by the strap mold base 910 into which the strap material was injected, and by the dampening mold 930 , which includes the head dampener cavity 906 . Such association of a strap mold base 910 and a dampening mold 930 may be achieved a variety of ways, such as by horizontal or vertical rotation of the mold base 910 after the first curing time, and registration of the mold base 910 with the dampening mold 930 . Basically, the molding process may be achieved through any known or later developed molding technologies, including core toggle molding, robotic transfer, rotary platen, indexing plate and horizontal rotary stack.
Alternatively, rather than modifying a tie mold or changing tie molds, a second material may be applied or disposed directly cote the bundle tie in a preferred pattern, or a cured second material may be adhered to the bundle tie. The application of a second material directly onto the bundle tie may be achieved by extruding a bead of the second material substantially contemporaneously with the placement of the second material onto the bundle tie.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shows and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. | An apparatus according to the present invention provides a bundle tie including a head dampener. The tie generally comprises a strap and a tie head coupled to the strap. The tie head is adapted to engage a free end of one strap, thereby forming a loop, which may be formed or placed about one or a bundle of elongate articles such as conduit, wires, cables, ropes, and pipes, for example. The tie head is provided with a head dampener which serves to cushion what otherwise may be damaging force placed upon the one or more elongate articles by the tie head. The dampener may also serve to limit movement of the one or more elongate articles through the loop formed by the tie. | 5 |
BACKGROUND OF THE INVENTION
i) Field of the Invention
This invention relates to processes for producing diarylacetylenes and enamines which are valuable in the synthesis of homopolymers and copolymers, for example, poly(arylether)s, polyesters, polycarbonates and polyformals.
ii) Brief Description of Prior Art
Advanced composite materials are made from combinations of high performance fibers, such as glass, graphite, carbon, silicon carbide or ceramic fibers, arranged in close packed alignment in the polymer as a matrix. Such composite materials provide a combination of strength and modulus superior to that of structural metals and alloys on an equal weight basis. Such composites are, for example, employed in military and commercial aircraft, and space vehicles, as well as in sports and sailboats.
These composite materials are expensive, and so their use is confined to relatively high cost items. On the other hand, even though the raw materials for these advanced composites are expensive, over 70% of the costs associated with such composites result from the processing costs for their manufacture.
In particular, the currently used manufacturing processes produce volatiles during curing of the polymer matrix and such volatiles produce voids in the matrix which act as sites for structural failure. In order to minimize void formation during evolution of volatiles, the cure must be carried out over a long period, under reduced pressure and this manufacturing requirement is a major factor in the production cost.
Acetylenic groups have been proposed in polymers in order to provide reactive sites for cross-linking the polymers when heated. The potential advantage of such acetylenic groups is that no volatiles will be produced during curing or cross-linking.
The acetylenic groups have been introduced into polymer chains as terminal groups, pendant groups or internal groups.
Acetylene precursor polymers have been reviewed by Hergenrother (P. M. Hergenrother, J. Marcromol. Sci.-Rev. Macromol. Chem. C19(1), 1-34 (1980).
Most of the polymers with terminal acetylenic groups, that have been synthesized contain unsubstituted ethynyl groups on the ends of the polymer chains and they are generally end-capped low molecular weight oligomers which are synthesized in order to provide easier processability. Reinhardt et al (B. A. Reinhardt, F. E. Arnold and M. R. Unroe, U.S. Pat. No. 4,513,131 (1985)) have synthesized the simple bis(phenylethynylphenyl)ethers as potentially thermally curable resins and studied their thermal curing properties.
Polymers containing pendant phenylethynyl groups have been synthesized and these polymers have been thermally cured. Examples are described in the afore-mentioned Hergenrother article and in U.S. Pat. No. 4,375,536 (1983) of Hergenrother.
Polymers containing internal acetylene groups have been less studied. T. Takeichi, H. Date and Y. Takayama, J. Pol. Sci. Chem. Ed. 28, 1989 (1990) describes the synthesis of polyimides containing internal acetylene groups. The authors indicate that the diphenylacetylene groups must be linked in the metal position to provide effective cross-linking.
Synthesis of Diarylacetylenes
Synthetic methods are reviewed in "Comprehensive Organic Chemistry" Pergamonn Press, 1979, Vol. 1 and in The Chemistry of the Carbon-Carbon Triple Bond, Ed. Saul Patai, John Wiley & Sons 1978, Part 2.
I. Dehydrohalogenation Reactions
The most common method of synthesis is by dehydrohalogenation reactions of iodo, bromo or chloro compounds with strong bases, usually KOH, NaOH, alkoxides such as sodium methoxide or potassium tertiary butoxide or sodamide, or with hydrides, e.g. sodium hydride or with organometallic compounds such as butyl lithium. ##STR1##
The elimination of other groups, thiols, sulfides, sulfonic acids, phosphate esters, trialkyl tin hydrides and the elimination of tertiary amines in a Hofmann elimination has also been observed (pp. 776-81 of the afore-mentioned S. Patai).
II. Displacement Reactions
Copper acetylides can react with aryl halides to give diarylacetylenes (p 796 of S. Patai) and aryl halides also react with acetylenes in the presence of palladium catalysts (p 798 of S. Patai): ##STR2##
Benzotriazole, benzimidazole and triazoles, have been shown by Katritzky to behave as pseudohalogens in certain reactions, (e.g. A. R. Katritzky, Q.-H. Long and P. Lue, Tetrahedron Letters, 32,3597 (1991) they have demonstrated that dienamines can be synthesized from substituted benzotriazoles by reaction with sodium hydride. ##STR3##
In this reaction the benzotriazole moiety behaves as a pseudohalogen and is eliminated with base in the same way a halogen like bromine would be. This is discussed further in a review article (A. R. Katritzky, S. Rachwal and G. J. Hutchings, Tetrahedron 47,2683 (1991).
The production of enamines is described in U.S. Pat. No. 5,011,998 (1991) of A. S. Hay et al. As described by Hay et al, the enamines are readily hydrolyzed to deoxybenzoins which in turn are readily oxidized to benzils which are useful in the production of a variety of polymers.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a novel synthesis for chemical intermediates for polymer production.
It is a more particular object of this invention to provide processes for the production of diarylacetylenes.
It is a further particular object of this invention to provide a process for the production of enamines.
It is yet another particular object of this invention to provide novel enamines.
It is a still further object of this invention to provide a novel process for producing polymers having acetylenic linkages.
It is still a further object of this invention to provide novel polymers incorporating acetylenic linkages.
In accordance with one aspect of the invention there is provided a process for producing a chemical intermediate for polymer manufacture comprising: reacting a Schiff's base of formula (III):
Ar.sub.1 CH═NAr.sub.2 (III)
with an N-arylmethylheterocycle of formula (IV):
Ar.sub.3 --CH.sub.2 --N (IV)
a basic medium wherein Ar 1 , Ar 2 and Ar 3 are each independently selected from aryl and hetaryl, unsubstituted or substituted, one or more times, by radicals selected from F, Cl, Br; alkyl of 1 to 6 carbon atoms; alkenyl of 2 to 6 carbon atoms; aryl of to 12 carbon atoms; aralkyl of 7 to 18 carbon atoms; aralkenyl of 8 to 18 carbon atoms, alkoxy of 1 to 6 carbon atoms; thioalkoxy of 1 to 6 carbon atoms; aryloxy of 6 to 12 carbon atoms; and thioaryloxy of 6 to 12 carbon atoms; and --N is a hetaryl radical.
If the process is operated under conditions favouring the elimination of the heterocyclic of formula (V):
H--N (V)
the reaction proceeds to form a diarylacetylene of formula (I):
Ar.sub.1 --C.tbd.C--Ar.sub.3 (I)
in which Ar 1 and Ar 3 are as defined above, as the favoured reaction.
If the process is operated under conditions which do not favour elimination of the heterocyclic of formula (V):
H--N (V)
the reaction forms an enamine of formula (II): ##STR4## wherein Ar 1 , Ar 3 and --N are all as defined above.
In another aspect of the invention there is provided enamines of formula (II), as defined above.
In yet another aspect of the invention there is provided a process for producing diarylacetylenes from the enamines (II).
In still another aspect of the invention there is provided a process of producing polymers and copolymers incorporating acetylenic compounds.
In yet another aspect of the invention there is provided novel polymers and copolymers having acetylenic groups incorporated therein.
DESCRIPTION OF PREFERRED EMBODIMENTS
i) Synthesis of Intermediates
A novel synthesis of the invention comprises the reaction of the Schiff's base of formula (III), as defined above with the N-arylmethylheterocycle of formula (IV), as defined above in a basic medium.
This reaction can produce a diarylacetylene of formula (I), as defined above, or an enamine of formula (II), as defined above, or a mixture containing both.
The hetaryl radical --N is, in particular, one which behaves as a pseudohalogen, and if the reaction conditions favour elimination of the heterocycle of formula (V):
H--N (V)
the reaction proceeds with formation of the diarylacetylene (I) as the major reaction product, whereas if the reaction conditions do not favour elimination of heterocycle (V), the reaction proceeds with formation of the enamine (II) as the major reaction product.
In general, higher reaction temperatures in conjunction with strongly basic conditions favour the elimination reaction which results in the diarylacetylene (I) as the major reaction product. In contrast, lower reaction temperatures in conjunction with weakly basic conditions do not favour the elimination reaction, thus leading to the enamine (II) as the major reaction product.
Reaction time is also a factor in determining whether the diarylacetylene (I) or the enamine (II) is the dominant reaction product.
Depending on the inter-relationship between product may be predominantly the diarylacetylene (I) or the enamine (II), or a mixture of both in varying proportions.
The reaction resulting in the diarylacetylene (I) proceeds via the enamine (II) as an intermediate. The diarylacetylene (I) can be produced from the intermediate enamine (II) in situ, or the enamine (II) can be recovered or isolated from the reaction medium and subjected to conditions favouring formation of the diarylacetylene (I).
Thus the invention contemplates reaction of the Schiff's base (III) and the N-arylmethylheterocycle (IV) under basic conditions favouring elimination of the heterocycle (V) so that the reaction proceeds to the diarylacetylene (I) via the enamine (II). The invention also contemplates reaction of (III) and (IV) under first basic conditions which do not favour eliminaton of the heterocycle (V) to produce the enamine (II), and thereafter, possibly with prior isolation of the enamine (II), reacting the enamine (II) under second basic conditions effective for elimination of the heterocycle (V) to produce the diarylacetylene (I).
The invention also contemplates the elimination process in which the diarylacetylene (I) is produced from the enamine (II), as starting material.
ii) Process Parameters for Synthesis
The synthesis i) is carried out under basic conditions, more especially in a basic medium.
In particular, the medium suitably comprises a polar, aprotic organic solvent, for example, dimethylformamide, dimethylacetamide or N-methylpyrrolidone, which medium is rendered basic. The base character may be achieved by the presence of a base, for example, sodium or potassium tert-butoxide, sodium amide or sodium dimethyl amide; the sodium dimethyl amide may be generated in situ from sodium in N,N-dimethyl formamide. Mixtures of the bases may be employed.
As indicated above the base selected plays a role in determining whether the formation of the diarylacetylene (I) or the enamine (II) is favoured.
Since some heterocycles (V) have a strongly acidic character, the heterocycle (V) formed as a by-product of the formation of the diarylacetylene (I) from the enamine (II), may act as a buffer in the reaction medium, weakening the basic character and favouring termination of the reaction with formation of enamine (II).
The synthesis can be carried out conveniently at temperatures in the range of 0° to 100° C.; while still lower or higher temperatures outside this range can be employed; there is no advantage in employing temperatures outside this range.
In general lower temperatures in the range favour the first stage of the reaction to produce enamine (II) as the major reaction product. On the other hand, higher temperatures alone do not dictate continuation of the reaction through the enamine (II) to the diarylacetylene (I); and at the higher temperatures, the reaction time and the strength of the basic character of the reaction medium play a significant role in determining which reaction product, (I) or (II), dominates; and, as indicated above, when considering the basic character of the reaction medium, it is not only the strength of the base employed which is to be considered, because the acidity of by-product heterocycle (V) also affects the basic character.
On the other hand, a surprisingly fast reaction to form a high yield of diarylacetylene (I) has been observed employing a basic reaction medium of potassium t-butoxide in dimethylformamide even when benzotriazole, which is strongly acidic, was formed as the by-product heterocycle (V). At a temperature of 75° C. the reaction proceeded to form the diarylacetylene in high yield in a reaction time of less than 1 minute.
At lower temperatures, however, the benzotriazole released buffered the reaction to favour the enamine (II) as the reaction product.
The rapid reaction with benzotriazole as the heterocyclic (V) presumably results from the high electron withdrawing character of the benzotriazolyl radical.
iii) Reactants
The Schiff's bases (III) are readily produced in condensation reactions between aromatic aldehydes and aromatic amines, a reaction fully described in prior literature.
The N-arylmethylheterocycles (IV) are readily produced by the reaction between arylmethylhalides and aromatic heterocyclic compounds under conditions for elimination of hydrogen halide, a reaction fully described in prior literature.
The aryl radicals Ar 1 , Ar 2 and Ar 3 are suitably aromatic radicals independently selected from: ##STR5## wherein x and y are integers independently selected from 0, 1, 2 or 3, z is an integer independently selected from 0, 1 or 2 and R, R' and R" are each independently selected from halogen atoms selected from fluorine, chlorine and bromine; alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms; aryl of 6 to 12 carbon atoms, aralkyl of 7 to 18 carbon atoms; aralkenyl of 8 to 18 carbon atoms; alkoxy of 1 to 6 carbon atoms; thioalkoxy of 1 to 6 carbon atoms; aryloxy of 6 to 12 carbon atoms and thioaryloxy of 6 to 12 carbon atoms.
The hetaryl radicals Ar 1 , Ar 2 and Ar 3 may be, for example, pyridinyl, furanyl, thiophenyl, thiazolyl or quinolinyl, which may be unsubstituted or substituted in the manner of the aryl radicals described above; for example the radicals: ##STR6##
The heterocyclic radical:
--N
may be, for example, a benzimidazolyl, benzotriazolyl, triazolyl or tetrazolyl, which radicals may be unsubstituted or substituted. It will be understood that the nature of the substituent is immaterial, provided that it does not interfere with the reaction to produce the desired enamine (II) or diarylacetylene (I).
iv) Polymer Production
Diarylacetylenes of formula (VI):
X.sub.1 --Ar.sub.4 --C.tbd.C--Ar.sub.5 --X.sub.2 (VI)
in which X 1 and X 2 are independently selected from F and OH, and Ar 4 and Ar 5 are aryl or hetaryl as defined for Ar 1 and Ar 3 , are starting materials for producing polymers which incorporate acetylenic groups.
The diarylacetylenes (VI) in which X 1 and X 2 are both fluorine are within formula (I) and are produced by the previously described synthesis of the invention.
The diarylacetylenes (VI) in which at least one of X 1 and X 2 is a hydroxyl are produced from the corresponding diarylacetylenes (VI) in which X 1 and X 2 are fluorine, by hydrolysis of one or both fluorine substituents or etherification of one or both fluorine substituents and hydrolysis of the resulting alkoxy or aryloxy substituents.
The reaction to replace one or both fluorine substituents by an alkoxy or aryloxy is a novel reaction and it was surprising that such reaction would proceed efficiently. It appears that the acetylenic linkage activates the fluorine atom, facilitating its displacement, but this was not to have been expected. The reaction proceeds efficiently in the presence of an alkali metal alkoxide or aryloxide in a polar, aprotic organic solvent. The reaction is illustrated in the following scheme ##STR7## in which X is H or F and R is alkyl or aryl, and Ar 4 and Ar 5 are as defined previously.
The production of homopolymers and copolymers, particularly poly(arylether)s, polyesters, polycarbonates and polyformals from diarylacetylenes (VI) is illustrated below: ##STR8##
In these reactions n is an integer indicating the length of the polymer chain.
Any bisphenol can be employed as the reactant HO-Ar--OH-- in the production of the poly(arylether). The radical Ar 1 is an aromatic moiety such as diphenylsulfone or benzophenone. When X is fluorine Ar 1 can also be a heterocyclic which activates the fluorine for nucleophilic substitution, for example, pyridine, benzoxazole, quinoxaline, an isoquinoline or a phthalazine.
Thus in another aspect of the invention there is provided a process for producing an acetylenic group-containing polymer or copolymer of the formula (VII): ##STR9## wherein Z 1 is fluorine, hydroxyl or mercaptyl, Z 2 is hydrogen or fluorine, Z 3 is --O--, --S--, --CH 2 --, --CO--, --CO--Ar 6 --CO-- or --Ar 7 --, in which Ar 6 and Ar 7 are selected from divalent aromatic linkages, Y 1 and Y 2 are each selected from --O-- and --S--, provided that when Z 3 is --O-- or --S--, Y 1 and Y 2 are both single bonds, Ar 4 and Ar 5 are each independently selected from arylene and hetarylene, unsubstituted or substituted one or more times by radicals selected from F, Cl, Br, alkyl of 1 to 6 carbon atoms; alkenyl of 2 to 6 carbon atoms; aryl of 6 to 12 carbon atoms; aralkyl of 7 to 18 carbon atoms; aralkenyl of 8 to 18 carbon atoms, alkoxy of 1 to 6 carbon atoms, thioalkoxy of 1 to 6 carbon atoms, aryloxy of 6 to 12 carbon atoms and thioaryloxy of 6 to 12 carbon atoms; X is --Ar 4 --C.tbd.C--Ar 5 or a copolymer unit, n is an integer of 2 to 200, x is an integer of 0 to 199 and n is >x.
It will be understood that the two basic units of (VII) may be in a random or non-random arrangement or sequence in the case of a copolymer.
In still another aspect of the invention there is provided an acetylenic group-containing polymer or copolymer of formula (VII) as defined above provided that when the polymer or copolymer has acetylenic units --Ar 4 --C═C--Ar 5 -- at both terminal positions, n is at least 3.
The divalent linkages --Ar 7 -- are in particular derived from dihydroxy aromatics, for example, bisphenols, or from dihaloaromatics in which the halo groups are activated by the presence of electron withdrawing groups such as sulphonyl or carbonyl groups.
Aromatic groups having electron withdrawing groups are thus, for example:
--Ar--CO--Ar--
and
--Ar--SO.sub.2 --Ar--
in which the Ar groups are the same or different and are arylene or hetarylene.
The divalent aromatic linkages Ar 6 are selected from a broader class than Ar 7 since no electron withdrawing group is required in Ar 7 .
The copolymer unit X may be derived from a wide variety of comonomers, for example, the following comonomer units in which the free valencies are in ortho or para positions. ##STR10## in which Ar 1 , Ar 2 , Ar 3 and Ar 4 are independently selected from unsubstituted and substituted aryl. ##STR11## in which Ar 1 , Ar 2 , Ar 3 and Ar 4 are as defined above and Ar is aryl. ##STR12## in which R 2 is alkylene or arylene ##STR13##
The aromatic moieties of the dihydroxy aromatics may be, for example, arylene and biarylene moieties including the following ##STR14##
The diarylacetylenes (I) as a class can be readily oxidized to corresponding benzils useful in synthesis of a variety of polymers including polyquinoxalines, polyphenyls and phthalic anhydrides and the latter can be reacted with diamines to produce polyimides.
The enamines (II) of the invention are useful for the production of deoxybenzoins which can be oxidized to benzils which have utility in the production of polymers. The processes, involving use of enamines, described in U.S. Pat. No. 5,011,998, the teachings of which are hereby incorporated herein by reference, apply to the enamines (II) of the present invention.
Thus deoxybenzoins, benzils and polymers may be produced using the enamines (II) of this invention, and the procedures described in U.S. Pat. No. 5,011,998, incorporated herein by reference.
EXPERIMENTAL
I. Synthesis of N-Benzyl-substituted Heterocyclics ##STR15##
Example 1
(Phenylmethyl)-1H-benzimidazole
To benzyl chloride (13 g, 0.103 mol), 1h-benzimidazole (11.81 g, 0.10 mol), K 2 CO 3 (60 g, 0.434 mol) was added acetonitrile (200 mL) and the mixture was stirred and heated under reflux for 3 h, filtered hot, and washed with hot CH 3 CN (100 mL). The solvent of the filtrate was evaporated and the residual mass recrystallized as needles (16.5 g, 79%): mp 119°-120° C. (benzene)(lit 1 mp 105° C.); 1 H NMR (270 MHz, CDCl 3 ) δ 5.40 (s, 2H, CH 2 ), 7.20-7.41 (m, 8H), 7.85-7.89 (m, 1H), 8.02 (s, 1H, NCHN); IR (CDCl 3 ) 3093 (w), 3065 (w), 3037 (w), 2929 (w), 1615 (w), 1496 (s), 1456, 1385 (w), 1361, 1331, 1285, 1261, 1204, 1181, 1007 (w), 963 (w), 947 (w) cm -1 . MS (EI) m/e 208 (M + , 57.8), 91 (100); Anal. Calcd for C 14 H 22 N 2 (208.26): C, 80.74; H, 5.81; N, 13.45; Found: C, 80.70; H, 6.02; N, 13.31.
Example 2
(Phenylmethyl)-1H-benzotriazole
(Phenylmethyl)-1H-benzotriazole was prepared from 1H-benzotriazole (11.91 g, 0.100 mol) and benzyl chloride as in Example 1 for 1 hour to give the title compound and (phenylmethyl)-2H-benzotriazole in a ratio of 75:25. Workup and two recrystallizations gives the pure 1H-isomer: mp 117°-119° C. (CH 3 CN); (lit. 1 mp 114°-117° C.; lit. 2 ,3 mp 115°-116° C.).
Example 3
(Phenylmethyl)-1H-[1,2,4-triazole]
(Phenylmethyl)-1H-[1,2,4-triazole] was prepared from 1H-[1,2,4-triazole] (69.7 g, 0.100 mol) and benzyl chloride as in Example 1 for 1 hour to give the title compound and (phenylmethyl)-2H-[1,2,4-triazole]. Workup and recrystallization gave the pure 1H-isomer (54%): mp 52°-53° C. (cyclohexane); (lit. 1 mp 54° C.).
Example 4
(2-Naphthalenyl)methyl-1H-benzotriazole
A procedure similar to Example 2 from 1H-benzotriazole and 2-naphthylmethyl chloride gave the title compound after recrystallization in 45% yield: mp 152°-153° C. (CH 3 CN); 1 H NMR (200 MHz, CDCl 3 ) δ 6.03 (s, 2H, CH 2 ), 7.32-7.38 (m, 4H), 7.48-7.53 (m, 2H), 7.77-7.83 (m, 4H), 8.07-8.12 (m, 1H).
Example 5
(1-Naphthalenyl)methyl-1H-benzotriazole
A procedure similar to Example 2 from 1H-benzotriazole and 1-naphthylmethyl chloride gave the title compound after recrystallization in 85% yield: mp 149°-151° C. (EtOAc/petroleum ether 35°-60° C. abbreviated elsewhere as PE), 1 H NMR (200 MHz, CDCl 3 ) δ 6.36 (s, 2H, CH 2 ), 7.29-7.59 (m, 7H), 7.87-7.93 (m, 2H), 8.06-8.11 (m, 1H), 8.21-8.26 (m, 1H).
Example 6
(4-Fluorophenyl)methyl-1H-benzotriazole
In a procedure as in Example 2 but using 1H-benzotriazole (23.8 g, 0.200 mol), 1-(chloromethyl)-4-fluorobenzene (29.0 g, 0.200 mol) and K 2 CO 3 (70 g) in CH 3 CN (300 mL) for 1 hour gave the title compound and (4-fluorophenyl)methyl-2H-benzotriazole. Workup and recrystallization gave the mixture of the 1H and 2H-isomers (75% yield) which was used in the subsequent reactions. A sample (5 g) was chromatographed (PE/EtOAc 9:1) eluting first the 2H isomer and then the title compound: mp 92°-94° C. (cyclohexane); 1 H NMR (300 MHz, CDCl 3 ) δ 5.82 (s, 2H, CH 2 ), 7.00-7.06 (m, 2H), 7.25-7.46 (m, 5H), 8.08 (d, J=8.9 Hz, 1H); IR (CDCl 3 ) 3052 (w), 2938 (w), 1609, 1513, 1451 (w), 1351 (w), 1315 (w), 1269 (w), 1230 (s), 1159, 1084 cm -1 . MS (EI) m/e 227 (M + , 52.6), 198 (100), 109 (96.9); Anal. Calcd or C 13 H 10 N 3 F (227.24): C, 68.71; H, 4.44; F, 8.36; N, 18.49; Found: C, 68.44; H, 4.44; F, 8.40; N, 18.57.
Example 7
(3-Fluorophenyl)methyl-1H-benzotriazole
In a procedure as in Example 2 but using 1H-benzotriazole (20.6 g, 0.173 mol), 1-(chloromethyl)-3-fluorobenzene (25.0 g, 0.173 mol), K 2 CO 3 (35.9 g) and CH 3 CN (150 mL) for 1 h gave the title compound and (3-fluorophenyl)methyl-2H-benzotriazole. Similar workup and recrystallization gave the pure 1H-isomer (73%): mp 103°-104° C. (cyclohexane); 1 H NMR (270 MHz, CDCl 3 ) δ 5.87 (s, 2H, CH 2 ), 6.97-7.08 (m, 3H), 7.29-7.49 (m, 4H), 8.10 (d, J=8.0 Hz, 1H); Anal. Calcd for C 13 H 10 N 3 F (227.24): C, 68.71; H, 4.44; Found: C, 68.40; H, 4.67.
Example 8
(2-Fluorophenyl)methyl-1H-benzotriazole
In a procedure as in Example 2 but using 1H-benzotriazole (34.5 g, 0.289 mol) and 1-(chloromethyl)-2-fluorobenzene (41.8 g, 0.289 mol) for 1 h gave the title compound and (2-fluorophenyl)methyl-2-H-benzotriazole in a ratio of 80:20. Similar workup and recrystallization gave the pure 1H-isomer (73%): mp 93°-95° C. (cyclohexane); 1 H NMR (270 MHz, CDCl 3 ) δ 5.93 (s, 2H, CH 2 ), 7.08-7.47 (m, 7H), 8.10 (d, J=7.2 Hz, 1H).
II. Synthesis of Schiff Bases ##STR16##
Example 9
N-[(4-fluorophenyl)methylene]benzenamine
To 4-fluorobenzaldehyde (24.8 g, 0.200 mol) and aniline (18.6 g, 0.200 mol) was added benzene (200 mL) and acetic acid (0.7 mL) and the mixture is heated under reflux until all the water (3.6 mL) was azeotropically removed. The solvent is evaporated and the residual oil upon cooling and stirring crystallized. The white mass was then recrystallize as needles (28 g, 70%): mp 39°-40° C. (PE) (lit. 1 mp 40° C.).
Example 10
N-[3-fluorophenyl)methylene]benzenamine 1 ,2
A similar procedure as for the preparation of N-[4-fluorophenyl)methylene]benzenamine (no acetic acid required) gave an oil which was distilled (87%): bp 100°-101° C./0.75 mm Hg.
Example 11
N-[(2-fluorophenyl)methylene]benzenamine
A similar procedure as for the preparation of N-[(4-fluorophenyl)methylene]benzenamine (no acetic acid required) gave an oil which was distilled (90%): bp 103°-104° C./1.5 mm Hg pressure; (lit. 1 bp 135° C.).
III. Synthesis of Enamines ##STR17##
(1,2-diphenylethenyl)-1H-benzotriazole
Example 12
Method 1
To a mixture of powdered KOH (2.24 g, 0.040 mol) and DMF (18 mL) there was added with radpis stirring phenylmethyl-1H-enzotriazole (1.05 g, 0.005 mol) and N-phenylmethylenebezenamine (0.905 g, 0.005 mol) in DMF (7 mL) at 75° C. After five minutes the reactin was poured into ice-cold water (75 mL) and left to crystallize the title enamine. This was filtered, washed with water, and dried to yield 1.07 g (72%) of the titel enamine. An analytical sample was chromatographed PE/EtOAc 4:1 and recrystallized with charcoal treatement: mp 152°-154° C. (cyclohexane); Anal. Calcd for C 20 H 15 N 3 (297.36): C, 80.78; H, 5.08; N, 14.13; Found: C, 80.66; H, 5.14; N, 14.14.
Example 13
Method 2
A procedure similar to Example 12 except that instead of KOH potassium t-butoxide (0.56 g, 0.005 mol) was used. At 75° C. the reaction was complete and worked up as above. Chromatography first with PE elutes some (5-10%) diphenyl acetylene and then PE/EtOAc 4:1 elutes the title enamine (75-80%). This method was applied to other bases as given in Table 1.
Example 14
(1,2-Diphenylethenyl)-1H-benzimidazole
A procedure as in Example 13 using (phenylmethyl)-1H-benzimidazole gave the enamine (82%): mp 141°-143° C. (cyclohexane); 1 H NMR (300 MHz, CDCl 3 ) δ 6.82 (m, 2H), 6.98 (d, J=8.0 Hz, 1H), 7.14-7.19 (m, 5H), 7.25-7.38 (m, 6H), 7.83 (s, 1H, NCHN), 7 (88, J=d, 9.0 Hz, 1H); IR (CDCl 3 ) 3085 (w), 3063, 3032 (w), 1635, 1611 (w), 1491 (s), 1484, 1452, 1391, 1365 (w), 1308, 1284, 1259, 1218, 1183 (w), 1078 (w), 1031 (w), 1006 (w) cm -1 . MS (EI) m/e 296 (M + , 100), 219 (13), 178 (52); Anal. Calcd for C 21 H 16 N 2 (296.38): C, 85.11; H, 5.44; N, 9.45; Found: C, 85.03; H, 5.50; N, 9.45.
Example 15
[1,2-bis(4-fluorophenyl)ethenyl)]-1H-benzotriazole
A procedure as in Example 13 using (4-Fluorophenyl)methyl-1H-benzotraizole. gave the title enamine (60%): mp 134°-136° C. (cyclohexane); MS (EI) m/e 333 (M+, 5), 305 (50), 304 (100), 303 (32), 215 (20), 214 (23), 183 (62); Anal. Calcd for C 20 H 13 F 2 N 3 (333.34): C, 72.06; H, 3.93; F, 11.4; N, 12.61; Found: C, 72.28; H, 3.93; F, 11.11; N, 12.74
IV. Synthesis of Acetylates ##STR18##
Diphenylacetylene
General Procedure
Example 16
Method a
To potassium t-butoxide (3.36 g, 30 mmol) in DMF (40 mL) at 75° C. was added as quickly as possible and all at once the [arylmethyl]-1H-benzotriazole (10 mmol) and N-(arylmethylene)benzenamine (10 mmol) dissolved in DMF (10 mL). Within a minute the solution is poured into ice-cold water (150 mL), extracted with CHCl 3 (3×50 mL) and chromatographed (PE). The acetylenes were recrystallized from MeOH. Thus was obtained: diphenylacetylene (75%): mp 59°-61° C. (MeOH); IR (CDCl 3 ) 1650 (w), 1604 (w), 1589 (w), 1512 (s), 1233, 1155 (w) cm -1 .
Example 17
Method b
To potassium t-butoxide (5.6 g, 50 mmol) in DMF (40 mL) at 75° C. was added N-(phenylmethyl)-1H-benzimidazole (2.08 g, 10 mmol) and N-(phenylmethylene)benzenamine (1.81 g, 10 mmol) dissolved in DMF (10 mL). After 5 hours the solution is poured into ice-cold water (150 mL), extracted with CHCl 3 (3×50 mL) and chromatographed (PE). Diphenylacetylene was obtained in 73% yield.
Example 18
Method c
To potassium t-butoxide (5.6 g, 50 mmol) in DMF (40 mL) at 75° C. was added N-(phenylmethyl)-1H-1,2,4-triazole (1.59 g, 10 mmol) and N-(phenylmethylene)benzenamine (1.81 g, 10 mmol) dissolved in DMF (10 mL). After 30 minutes the solution is poured into ice-cold water (150 mL), extracted with CHCl 3 (3×50 mL) and chromatographed (PE). Diphenylacetylene was obtained in 11% yield.
TABLE 1__________________________________________________________________________Influence of different bases and temperatures on the reaction ofphenylmethy-1H-benzotriazole (5 mmol) andN-phenylmethylenebenzenamine (5 mmol) in DMF (25 mL)in the production of the enamine (1) and diphenylacetylene (2). YieldTemp. Time Base (mmol) (%)Example (°C.) (min) NaNH2 Na t-BuOH KOt-Bu 1 2__________________________________________________________________________19 75 30 0 22 0 0 0 5520 75 50 0 4.8 2.3 0 55 521 60 30 0 9.1 4.6 0 61 022 75 60 0 4.8 0 0 32 023 50 20 0 0 0 5 40 3524 22 20 0 0 0 2.5 60 025 0 80 0 0 0 3.57 56 026 75 70 15 0 0 0 47 527 75 1100 0 22 11 0 3 42__________________________________________________________________________
Example 28
1-(Phenylethynyl)naphthalene
In a procedure similar to that of Example 16 using [phenylmethyl]-1H-benzotriazole (10 mmol) and N-([1-naphthalenyl]methylene)benzenamine (10 mmol): 88% yield: mp 51°-53° C. (MeOH) (lit 1 oil); 1 H NMR (300 MHz, CDCl 3 ) δ 7.39-7.69 (m, 8H), 7.77-7.90 (m, 3H), 8.46 (br d, 2.7H, 1H); IR (CDCl 3 ) 3060 (s), 2245 (eyne), 1596, 1581, 1508, 1491 (s), 1442, 1398, 1333, 1215, 1070, 1017 cm -1 . MS (EI) m/e 228 (M + , 100).
Example 29
1-Methoxy-4-(phenylethynyl)benzene
Procedure similar to that of Example 16 using [phenylmethyl]-1Hbenzotriazole (10 mmol) and N-[(4-methoxyphenyl)methylene]benzenamine (10 mmol): 67% yield: mp 57°-58° C. (MeOH) (lit. 1 58°-60° C.); 1 H NMR (300 MHz, CDCl 3 ) δ 3.84 (s, 3H, OCH 3 ), 6.89 (d, 1.9H, 2H, C(3 and 5)H), 7.30-7.38 (m, 3H(), 7.45-7.54 (m, 4H).
Example 30
Bis(4-fluorophenyl)acetylene
To potassium t-butoxide (1.5 g, 13.4 mmol) in DMF (15 mL) at 75° C. was added as quickly as possible and all at once [(4-fluorophenyl)methyl]-1-H-benzotriazole (1.14 g, 5 mmol) and (4-fluorophenyl)methylenebenzenamine (1.00 g, 5 mmol) dissolved in DMF (10 mL). Within a minute the solution is poured into ice-cold water (75 mL) crystallizing the title compound which was filtered and then chromatographed (PE). The acetylene 0.54 g (50%) recrystallizes as needles: mp 95°-96° C. (MeOH); (lit. 1 94°-95° C.).
Example 31
4-(t-Butoxy)-4'-fluorodiphenylacetylene
A similar procedure as for the preparation of bis(4-fluorophenyl)acetylene in Example 30 but stirred at 75° C. for 15 min and then quenched with water gave the title acetylene (15% HPLC) and bis(4-fluorophenyl)acetylene (30% HPLC). Chromatography (PE) elutes the difluoro derivative then PE/EtOAc 97:3 elutes the title compound recrystallizing as colorless plates 2.5 g (10%): mp 102°-104° C. (MeOH); 1 H NMR (200 MHz, CDCl 3 ) δ 1.35 (s, 9H, (CH 3 ) 3 ), 6.93-7.06 (dd, J=8.6 Hz, 4H), 7.39-7.51 (m, 4H); IR (CDCl 3 ) 3020 (w), 2981, 2247 (w,(acetylenic stretch), 1605, 1515 (s), 1474 (w), 1393 (w), 1367, 1281 (w), 1234, 1218, 1157 (s) cm -1 . MS (EI) m/e 268 (M+ (4.5)), 212 (100), 183 (28), 157 (9.4); Anal. Calcd for C 18 H 17 FO (268.33): C, 80.57; H, 6.39; Found: C, 80.10; H, 6.42.
Example 32
4,4'Bis(t-Butoxy)diphenylacetylene
A similar procedure as for the preparation of bis(4-fluorophenyl)acetylene.] in Example 30 but using 5 equiv of potassium t-butoxide for 150 minutes and then quenched with water gave the title acetylene (45% HPLC). Chromatography (PE/EtOAc 9:1) and recrystallization with charcoal treatment gave 0.64 g (40%) colorless prisms: mp 129°-131° C. (MeOH); 1 H NMR (300 MHz, CDCl 3 ) δ 1.36 (s, 18H, C(CH 3 ), 6.96 (d, J=8.7 Hz, 4H, phenyl C3and 3'H), 7.43 (d, 4H, phenyl C2 and 2'H); IR (CDCl 3 ) 3040 (w), 2980, 2936 (w), 2907, 2875, 1606, 1511, 1475 (w), 1394, 1367, 1309 (w), 1240, 1158 (s), 1101 (w), 1016 (w) cm -1 . MS (EI) m/e 322 (M + , 6.1), 266 ((4.1), 2.10 (100).
Example 33
1,2-Bis(4hydroxyphenyl)-ethanone
To a solution of acetic acid (15 mL), c. HCl (2.0 mL) and H 2 O (3.0 mL) was added 1,1'-(1,2-ethynediyl)bis[4-(1,1-dimethylethoxy)benzene] (1.0 g, 3.1 mmol) and heated under reflux 1.5 h. Then the solution was poured into ice-cold H 2 O (50 mL) precipitating the title compound which was filtered washed with water, air-dried, and recrystallized into tanned needles (0.52 g, 80% yield). A second recrystallization with charcoal treatment and acidification of the solution gave colorless needles: m 217°-220° C. (H 2 O) (lit 1 mp 214°-215° C.); 1 H NMR (300 MHz, DMSO-d 6 ) δ 4.09 (s, 2H, CH 2 ), 6.66 (d, J=8.45 Hz, 2H, C9H), 6.82 (d, J=8.7 Hz, 2H, C2H), 7.02 (d, 2H, C8H), 7.89 (d, 2H, C3H), 9.23 (s, 1H, C10OH), 10.34 (s, 1H, C1OH); 13 C NMR (300 MHz, DMSO-d 6 ) δ 43.44 (CH 2 ), 115.11, 115.20, 125.58, 127.85, 130.36, 130.54, 131.02, 131.17, 155.85, 161.97 196.18 (C═O); MS (EI) m/e 228 (M + , 4), 121 (100), 107 (14.8), 93 (13), 65 (15).
Example 34
1-Hydroxy-4-(phenylethynyl)benzene
A procedure similar to that described 1 was used. A sample of 1-methoxy-4-(phenylethynyl)-benzene (0.4 g, 1.9 mmol) was added collidine (3 mL), LiI (1.5 g) and the solution heated under reflux for 5 h (>95% conversion). The solution was poured into water acidified with HCl, extracted with ether (3×50 mL) and dried (MgSO 4 ). The ether was evaporated and the residue chromatographed (PE) eluting the title compound 0.3 g (80%): mp 125°-128° C. (cyclohexane) (lit 2 mp 91°-92°C., lit 3 mp 83°-84° C.); 1 H NMR (300 MHz, DMSO-d 6 ) δ 6.80 (d, J=8.77 Hz, 2H, C2H), 7.37 (d, 2H, C3H), 7.35-7.42 (m, 3H), 7.46-7.50 (m, 2H), 9.92 (s, 1H, OH); 13 C NMR (300 MHz, DMSO-d 6 ) δ 87.32 (acetylenic C), 89.98 (acetylenic C), 112.42 (sp 2 C), 115.74, 122.90 (sp 2 C), 128.20, 128.66, 131.06, 133.00, 158.06 (COH); IR (CDCl 3 ) 3596 (OH), 3066 (w), 3039 (w), 2217 (w, acetylenic stretch), 1605, 1512, 1429 (w), 1328 (w), 1261 (s), 1219, 1171 (s), 1140 (w), 1099 (w), 834, 805 (w) cm -1 . MS (EI) m/e 194 (M + , 100), 165 (29.4), 97 (11.3).
Example 35
4,4'-Bis(phenoxy)diphenylacetylene
To 4,4'-difluorotolane (0.5 g, 0.0023 mol) and dry potassium phenolate (prepared from aqueous KOH and phenol with azeotropic removal of H 2 O with benzene) (1.5 g, 0.011 mol) was added DMF (10 mL) and the mixture heated at 170° C. for 12 h after which there appeared a little difluorotolane remaining. This mixture was poured in water, the precipitate was filtered, washed with water, dried, and the title compound recrystallized as flakes 0.54 g (64%): mp 171°-173° C. (acetic acid) (lit. 1 mp 167°-168° C.); 1 H NMR (270 MHz, CDCl 3 ) δ 6.89 (d, J=8.7 Hz, 4H, phenylene (C3,3'H), 6.97 (d, J=8.6 Hz, 4H, phenyl C2,2'H) 7.07 t, J=7.9 Hz, 2H, phenyl C4H), 7.29 (t, 4H, phenyl C3,3'H), 7.40 (d, 4H, phenylene C2,2'H); IR (CDCl 3 ) 3041 (w), 3020 (w), 1590, 1512, 1488, 1312 (w), 1274 (w), 1238 (s), 1218, 1165 (w), 1020 (w) cm -1 . When the sample is placed in a DSC apparatus with a N 2 gas flow ramped at 10° C./min it shows a Tm=163.9° C. In a gas-tight crucible and the temperature ramped at 2° C./min this sample shows Tm=169.5° C. and an exotherm maximum at 359.3° C. The exotherm begins at ˜302° C. and ends at ˜396° C. Some of this material is heated in a closed glass capillary tube at 320°-330° C. for 6 h and then an aliquot of the product was chromatographed (HPLC). The retention times (tR in min) and area % were: 4.43 (8), 4.63 (6), 9.02 (40), 13.08 (6.5), 19.24 (15).
Example 36
3,3'-Difluorodiphenylacetylene
A simile procedure to Example 30 but using [(3-fluorophenyl)methyl]-1H-benzotriazole and (3-fluorophenyl)methylenebenzenamine, gave the title acetylene after recrystallization (30%) needles: mp 60°-62° C. (MeOH) (lit. 1 mp 61°-62° C., lit. 2 mp 55.5°-58° C.); 1 H NMR (300 MHz, CDCl 3 ) δ 7.04-7.11 (m, 2H), 7.22-7.25 (m, 2H), 7.31-7.35 (m, 4H); 13 C NMR (300 MHz, CDCl 3 ) δ 88.89 (2.9, ethynyl C), 115.92 (21.1, C4), 118.42 (22.9, C2), 124.60 (9.5, C1), 127.54 (2.9, C6), 129.97 (8.7, C5), 162.36 (246.7, C3).
Example 37
2,2'-Difluorodiphenylacetylene
A similar procedure to Example 30 but using [(2-fluorophenyl)methyl]-1H-benzotriazole and (2-fluorophenyl)methylenebenzenamine, gave the title acetylene after chromatography (PE) and recrystallization (15%) needles: mp 53°-54° C. (MeOH); 1 H NMR (200 MHz, CDCl 3 ) δ 7.05-7.16 (m, 4H), 7.27-7.38 (m, 2H), 7.50-7.58 (m, 2H); 13 C NMR (200 MHz, CDCl 3 ) δ 88.05 (2.6, acetylenic C), 112.03 (15.8, C1), 116.02 (21, C3), 124.49 (3.8, C6), 130.83 (8, C4), 134.06 (C5), 163.24 (253, C2); IR (CDCl 3 ) 3040 (w), 2228 (w, acetylenic stretch), 1951 (w), 1917 (w), 1883 (w), 1799 (w), 1700 (w), 1615 (w), 1576, 1501, 1447 (s), 1413 (w), 1321 (w), 1264 (s), 1224 (s), 115 (w), 1100, 1030 cm -1 . MS (EI) m/e 214 (M + , 100), 107 (12.8).
Example 38
2,4'-Difluorodiphenylacetylene
A similar procedure to Example 30 but using [(4-fluorophenyl)methyl]-1H-benzotriazole (1.14 g, 5 mmol) and (2-fluorophenyl)methylenebenzenamine (1.00 g, 5 mmol), gave the title acetylene after recrystallization (50%) needles: mp 108°-109° C. (MeOH); 1 H NMR (200 MHz, CDCl 3 ) δ 7.0-7.18 (m, 4H), 7.24-7.38 (m, 1H), 7.45-7.59 (m, 3H); 13 C NMR (200 MHz, CDCl 3 ) δ 82.77 (acetylenic C1), 93.72 (3.35, acetylenic C1'), 112.21 (15.39, C1), 116.03 (21.07, C3), 116.16 (22.18, C3'), 119.50 (3.41, C1'), 124.50 (3.67, C6), 130.57 (8.04, C4), 133.99 (8.15, C5 or C2'), 134.16 (8.5, C5 or C2'), 163.24 (252.45, C2 or C4'), 163.32 (250.7, C2 or C4'); IR (CDCl 3 ) 2263 (w), 2247 (etynyl stretch, w), 1600 (C═C), 1574 (w), 1510 (s), 1489, 1451, 1264, 1228, 1156, 1096, 1029 (w) cm -1 . MS (EI) m/e 214 (M + , 100).
Example 39
3,4'difluorodiphenylacetylene
A similar procedure to Example 30 but using [(4-fluorophenyl)methyl]-1H-benzotriazole (1.14 g, 5 mmol) and (3-fluorophenyl)methylenebenzenamine (1.00 g, 5 mmol), gave the title acetylene after recrystallization (60%) needle: mp 88°-89° C. (MeOH).
Example 40
Bis(2-naphthyl)acetylene
A procedure similar to Example 16 using N-([2-naphthalenyl]methylene)benzenamine and 2-naphthylmethyl chloride gave a 76% yield of product: mp 225°-226° C. (MeOH) (lit. 1 mp 228°-229° C.).
Example 41
Bis(1-naphthyl)acetylene
A procedure similar to Example 16 using N-([1-naphthalenyl]methylene)benzenamine and 1-naphthylmethyl chloride gave a 67% yield of product: mp 127°-128° C. (MeOH) (lit. 1 mp 129° C.).
Example 42
Methylenebis(4-oxyphenylethynyl)bisbenzene
A procedure similar to Example 16 but using [phenylmethyl]-1H-benzotriazole (2.09 g, 10 mmol) and 4,4'-methylenedioxybis(phenylmethylene)dianiline 1 (2.02 g, 5 mmol) for 1 h at 75° C. gave after chromatography (PE/EtOAc 4:1) the title acetylene (30%): mp 140°-143+ C. (cyclohexane); 1 H NMR (200 MHz, CDCl 3 ) δ 5.74 (s, 2H, CH 2 ), 7.05-7.10 (m, 4H), 7.30-7.35 (m, 6H), 7.45-7.52 (m, 8H); 13 C NMR (300 MHz, CDCl 3 ) δ 88.58 (acetylenic C), 88.97 (acetylenic C), 90.70, 116.36, 117.41, 123.36, 128.08, 128.31, 131.48, 133.09, 156.72; IR (CDCl 3 ) 3062 (w), 2978 (w), 2911 (w), 2217 (w, acetylenic stretch), 1599, 1573 (w), 1509, 1443 (w), 1414 (w), 1314 (w), 1279 (w), 1233, 1209 (s), 1175, 1137 (w), 1103 (w), 1014, 836 cm -1 . MS (EI) m/e 400 (M + , 64), 207 (100), 194 (18.7), 177 (83.7), 165 (24.3), 151 (27.0).
Example 43
2-(2-Phenylethynyl)furan
A procedure similar to Example 16 but with 2-(N-phenylaminomethylidine)furan (0.86 g, 0.005 mol) and (phenylmethyl)-1H-benzotriazole (1.05 g, 0.005 mol) gave after workup and chromatography (PE/EtOAc 4:1) an oil (90%, 98.5% pure) (lit. 1 oil bp 74° C./0.1 mm Hg) which darkened on standing: 1 H NMR (270 MHz, CDCl 3 ) δ 6.61 (dd, J= 34 3.33, 23 1.98 Hz, 1H, C3H), 6.855 (d, 1H), C4H), 7.52-7.55 (m, 3H, phenyl), 7.616 (d, 1H, C2H), 7.71 (m, 2H, phenyl); 13 C NMR (270 MHz, CDCl 3 ) δ 79.38 (CC(C 4 H 4 O)), 93.22 (PhCC), 111.03 (C4), 115.19 (C3), 122.25 (C1'), 128.35 (C3'), 128.65 (C4'), 131.38 (C2'), 137.12 (C2), 143.59 (C5); MS (EI) m/e 168 (M + , 100), 139 (96.8).
Example 44
3-(2-Phenylethynyl)pyridine
A procedure similar to Example 16 but with 3-(N-phenylaminomethylidine)-pyridine (0.911 g, 0.005 mol) and (phenylmethyl)-1Hbenzotriazole (1.05 g, 0.005 mol) gave after workup and chromatography (PE/EtOAc 4:1) and treatment with boiling PE white needles (80%): mp 47°-48° C. (PE) (lit. 1 mp 47°-48.5° C., acetylenic stretch 2200 cm -1 ); MS (EI) m/e 179 (M + , 100), 126 (21.7).
V. Synthesis of Indoles ##STR19##
Example 45
1-Phenyl-2-(4-fluorophenyl)-1H-indole
A solution of (2-fluorophenyl)methyl-1H-benzotriazole (1.13 g, 5 mmol) and N-[(4-fluorophenyl)methylidine]benzenamine (0.996 g, 5 mmol) in DMF (7 mL) was stirred into potassium t-butoxide (1.68 g, 15 mmol) in DMF (18 mL) preheated to 75° C. The reaction monitore by HPLC showed completion upon mixing. After 11 minutes the DMF solution was poured in ice-cold H 2 O (75 mL) extracted with CHCl 3 (3×50 mL) and the solvent was evaporated. Chromatography first using PE as eluted 1-(4-fluorophenylethynyl)[2-fluorobenzene] (vide infra) then the eluant was changed to PE/EtOAc 97:3 eluting the title indole (40%): mp 126°-128° C. (MeOH); 1 H NMR (200 MHz, CDCl 3 ) δ 6.77 (s, 1H, C3H), 6.94 (t, J=8.7 Hz, 2H, phenic H), 7.16-7.48 (m, 10H), 7.66-7.72 (m, 1H); MS (EI) m/e 287 (M + , 100).
VI. Polymer Synthesis ##STR20##
Example 46
Poly(phenylene ether yne
A mixture of 4,4'-(1-Methylethylidene)bisphenol (BPA) (1.141 g, 5 mmol), 4,4'-difluorodiphenylacetylene (1.071 g, 5 mmol) and anhydrous K 2 CO 3 (0.9 g, mmol) in toluene (10 mL) and N-methylpyrrolidone (NMP) (14 mL) was stirred and heated to the reflux temperature of toluene azeotropically removing the water for 5 hours under a slow stream of N 2 . The temperature was allowed to increase to 180° C. over a period of 5 hours allowing for the removal of toluene and NMP (4 mL). The dark mixture was then allowed to stir for an additional 10 hours when an aliquot flooded in MeOH precipitated high molecular weight polymer. The organics were cooled, filtered through celite, precipitated (MeOH), and dissolved in CHCl 3 , filtered and reprecipitated (MeOH), washed (H 2 O) and dried to yield 1.57 g of the title polymer: Tg=163° C. exotherm maximum 398° C. (temperature ramped at 20° C./min), ηinh 0.69 dL/g (TCE, 2.54° C.), Mw=54400 Mn=23300.
VIL. Copolymer Synthesis ##STR21## The following copolymers were synthesized as in Example 43 using the molar amounts of 4,4'difluorodiphenylacetylene and 4,4'dichlorodiphenyl sulfone shown in Table 2.
TABLE 2__________________________________________________________________________Properties of Copolymersn m Inherent Tg Tg after curing TGA (°C.)Example(mol %) Viscosity (°C.) 1 hr @ 340° C. N.sub.2 (-10%) Air Film Solubility__________________________________________________________________________47 5 95 0.39 208 218 511 522 Brittle CH.sub.2 Cl.sub.2 /CHCl.sub.348 10 90 0.4 210 225 526 530 Brittle CH.sub.2 Cl.sub.2 /CHCl.sub.349 30 70 0.64 188 277 522 531 Brittle NMP/TCE (hot)__________________________________________________________________________ | Diarylacetylenes and diarylenamines are synthesized from a Schiff's base and an N-arylmethylheterocycle; these compounds are useful as intermediates for a variety of polymers; in particular an efficient process is provided for producing diaryl acetylenes useful in the efficient production of acetylene group-containing polymers which can be cross-linked to produce high strength polymers free of structural defects such as conventionally arise as a result of liberation of volatiles during the cross-linking. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system used for waterproofing strain gage elements when in place on a member.
2. Description of the Prior Art
It has long been desired to have some way of sealing a strain gage when it's placed on a member that is to be loaded, such as a flexure member of an extensometer. Moisture problems are well known, and on bonded strain gages that are commonly used in many applications, high humidity, or operation when immersed in water, will cause resistance breakdown between the gage and its mounting. The drift of the gages also becomes impossible to compensate for in such situations.
Strain gages have a wide usage in a number of applications, and in particular a strain gage extensometer such as that shown in U.S. Pat. No. 3,789,508 has cross flexure elements supporting the arms of the extensometer with strain gages mounted on such flexure elements. The strain on the specimen with which the extensometer is used causes a movement of the arms and a bending or flexing of the flexure elements.
The specific usage shown herein is for this type of extensometer modified to accept a longer flexure element or spring and having the waterproofing system of the present invention incorporated thereon.
SUMMARY OF THE INVENTION
The present invention relates to a strain gage element system for use with extensometers, clip-on gages and other strain sensing devices that incorporates a waterproof cover so that it can operate in very high humidity or immersed in water. The waterproofing generally has to withstand a temperature range from about 40° to about 200° F. Essentially the strain gage mounting element comprises a spring flexure member or element on which one or more strain gages are mounted, which is preferably shaped along its longitudinal axis so that the peripheral distance around the periphery at any cross-sectional location along its longitudinal axis will be substantially the same. A "heat shrink" plastic tube is placed over the mounting element and the strain gages after the strain gages have been mounted and then the tube is heated to shrink tightly against the gages, the lead wires, and the spring flexure member on which the gages are mounted, to completely seal out any water.
If desired, the spring member can be made so that it can permit bleeding off of the air underneath the tube as the tube shrinks into place, and separate sealing cap members at opposite ends of the main heat-shrink tube can be used for insuring a tight seal at the ends.
In the form shown, the spring flexure member or element on which the gages are mounted has a generally flat section positioned between two mounting ends, which as shown are cylindrical, that are used for clamping the spring flexure member in position. The transition sections between the flat spring section on which the gages are mounted and the rounded ends are machined so that the peripheral distance of any cross section perpendicular to the axis is substantially the same. That means essentially that the center flat section, which is very thin, is also wider than the ends. When the peripheral or perimeter length of the cross section remains substantially the same, as the heat shrinkable tubing shrinks it will tighten down evenly throughout the length of the spring flexure member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational, part schematic view of a typical extensometer arrangement with which the strain gage element of the present invention is used;
FIG. 2 is an end view showing a typical mounting for the strain gage element of the present invention;
FIG. 3 is a sectional view of a strain gage element having a waterproofing system made according to the present invention installed; and
FIG. 4 is a top plan view of the device in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a typical use for a waterproof strain gage element system made according to the present invention is shown. An extensometer 10 is formed substantially as that shown in U.S. Pat. No. 3,789,508 except that the length of the horizontal flexure element is increased to use the strain gage element system of the present invention. The extensometer 10 includes an upper arm assembly 11, and a lower arm assembly 12 which are connected together at the base end thereof by a first vertically extending pair of strips forming flexure elements 13 corresponding to the elements 13 in U.S. Pat. No. 3,789,508. The flexure elements 13 are thin strips of flexible spring material and provide an open center portion through which a waterproof strain gage element 15 extends.
A flexure elements 13 are clamped into position with blocks 14 that are held in place with suitable screws to clamp the ends of the elements 13 against the base ends of the arms 11 and 12. A first end of the strain gage element 15 is clamped with a clamp 16 at an outer end of an elongated support arm 18 in a suitable manner. The support arm 18 is attached to the lower block 14 which is fixed to the lower arm 12. The opposite end of the strain gage element 15 is connected through a clamp indicated at 17 to the upper arm 11, approximately in the midpoint of the arm 11 as shown.
In a normal manner, the outer ends of the arms 11 and 12 have knife-edged blades 20, and 21 mounted thereon which engage a test specimen 22 that is to be tested. The extensometer is held on the specimen in any desired manner, as shown, with elastic bands. The specimen 22 is to be tested under either tension or compression loading and thus the specimen 22 will either elongate or shorten under the load.
In order to measure the strain in the specimen 22, the change in spacing of the blades 20 and 21 is measured as the element 22 is loaded in known manner. In the present invention the strain gage element system 15 and the flexure element 13 will bend as the blades 20 and 21 move relative to each other.
The element system 15 is formed to waterproof the gage, and is shown in detail in FIGS. 3 and 4. The strain gage element system 15 includes spring flexure member 26, which has a first cylindrical end portion 27, a second cylindrical end portion 28, which is, as shown of greater longitudinal length than end portion 27, and between these cylindrical end portions the spring member 26 has a flat spring section 29. The spring flexure member 26 is made of a hardened material that forms a spring, such as beryllium copper. The flat spring section 29 is joined to the cylindrical end sections 27 and 28, with transition zone sections 31 and 32 which are tapered in direction perpendicular to the plane of flat spring section 29 and they also are tapered in lateral width. The transition zone sections 31 and 32 are reduced both in thickness or height, and in width in order to maintain a substantially constant peripheral distance or length for the perimeter of cross sections at any place along the longitudinal axis 33 of the spring flexure member.
A cross sectional plane, for example, along a cutting plane perpendicular to axis 33 at location shown generally by the line 34 would have the same distance around its periphery as around the periphery of the cross section at a cross section plane along line 35, right in the center portions of the flat spring section 29. The circumferential distance around the cylindrical end portions 27 and 28 will be the same as the peripheral distances around the cross sections at cutting planes 34 and 35.
Strain gages shown generally at 37 are mounted on the opposite planar surfaces of the flat spring section 29, and are bonded in place in a normal manner. The strain gages 37 have electrical leads 38 leading therefrom. In order to insure a tight fit of the covering material for waterproofing, as will be explained, these leads are passed into a central passageway or bore indicated at 40 extending through the end portion 28. The passageway 40 is joined by ports 41 and 42, respectively on the opposite surfaces of transition zone section 32 so that the leads 38 from each of the gages 37 on the opposite sides of the flat spring section 29 can be passed through the passageway 40. This arrangement leaves a very small irregularity on the surface of the transition section 32 from the leads.
Additionally, the end portion 27 has a passageway or hole 45 drilled therein along the longitudinal axis and has a pair of ports 46 and 47 that open to the opposite surfaces of the transition section 31, and also open to the passageway 45.
The waterproof strain gage element system comprises the use of a heat-shrinkable plastic tube indicated generally at 50, which is a selected size that will fit over the spring flexure member 26, and will also slip over the flat spring section 29. The tube 50 is selected in length so that its end portion overlap the cylindrical sections 27 and 28. The tube 50 does not terminate in the transition sections. Once the heat shrinkable plastic tube 50 is positioned, which is after the strain gages 37 have been bonded in place with the leads 38 extending out through the passageway 40, the heat shrinkable tube 50 is subjected to sufficient heat to cause it to shrink. This will tighten the tube 50 down onto the cylindrical end portions 27 and 28, and at the same time will cause the tube 50 to shrink against the surface of the transition sections 31 and 32 and tightly encompass and encircle the leads 38.
At the same time, any air that is present within the tube 50 and which might otherwise become trapped will be permitted to bleed out through the ports 41 and 42 and passageway 40, and or through the ports 46 and 47 through passageway 45. If desired, a vacuum could be applied through the passageways 45 and or 40.
The waterproofing process can end that stage, if the sealing or fitting of the ends of tube 50 on the cylindrical end portions, such as in portions 51 and 52, respectively, is watertight. However, to insure adequate sealing and waterproofing, auxilliary tube sections or caps 53 and 54, respectively, can be slid over the opposite end portions 51 and 52 of the tube 50 and also heat shrunk into place. This will form a double seal with the tube end caps 53 and 54 shrinking on the outer surface of the end portions of the tube 50 and also shrinking down onto and sealing on the surfaces of cylindrical members 27 and 28 very tightly to provide a complete seal even if there is a slight break in the seal at the end portions 51 and 52.
Once the assembly of plastic tubes has been shrunk into place as desired, either with only the tube 50 in place or with the tube end caps 53 and 54 in place, the openings 45 and 40 can be sealed with suitable sealing material such as epoxy or other sealing compound. The strain gages 37 on the flat spring section 29 are completely sealed. The waterproof tube 50 extends from one cylindrical end portion to the other.
Because peripheral distance of the cross sections along any cutting plane perpendicular to the longitudinal axis 33 is substantially equal, the tube 50 will shrink evenly and tightly onto the transition sections 31 and 32, the end portions 27 and 28, and also onto the flat spring section 29, to completely keep out moisture, whether from humidity or actual operation under water. Because the tube 50 will shrink in size equally and because the peripheral distance of the cross sections are substantially equal, the sealing will be complete.
The outer parts of end sections 27 and 28 are not covered by tube 50 and are used for clamping the strain gage element assembly 15, comprising the waterproof strain gage element system, into the clamps on the extensometer arms, or in place on a clip-on gage or other strain sensing instrument.
It should be noted that the cross sectional shape of the end portions 27 and 28 does not have to be circular as shown, and in certain instances, such as with a clip gage arm, a rectangular cross sectional shape can be utilized for clamping. The flexing element may then taper both in width and height to a center bending section where strain gages are mounted. Whether the cross sectional shapes are round, rectangular, or other shapes, the peripheral distance or size around the cross section is important. It is desirable to keep the peripheral distance uniform for most satisfactory operation.
The method of waterproofing a strain gage flexure element comprises providing a spring flexure member on which the strain gages will be mounted; mounting the gages in a flexing portion of the spring member; covering the gages with a tubing that is made of a heat shrinkable material throughout the entire length of the gages and for a desired distance beyond the ends of the gages; shrinking the tubing down onto the spring member and gages, until a tight, waterproof adherence is achieved between the inner surface of the tube and the surfaces of the spring member at the opposite ends of the strain gage. Optionally, the spring member can be made so that it has a substantially equal peripheral length about any cross section perpendicular to the longitudinal axis; providing means to permit air to bleed through the member from the interior when the tubing is heat shrunk into place; and heat shrinking separate tubular cap sections at the ends of the first mentioned tube for extra sealing of these ends.
The heat shrink tubing is well known in the art and can be selected so that the heat required for shrinking the tubing does not have to be high enough so that the gages are damaged. The size, including the diameter and wall thickness of the tubing can be selected to meet the existing conditions. The waterproof strain gage element system of the present invention may be used for any mounting member for strain gages where a tube can be slipped over the member.
The tubing can be selected in properties as to wall thickness and percent of shrink under heat to insure that the tube conforms to the shape of the bendable member throughout its length and is stretched to tightly adhere to the member it surrounds.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | A strain gage element system includes a spring flexure member on which strain gages of convention design are mounted, and a heat shrinkable waterproof tube that is placed over the gage and the support and shrunk into place. The spring flexure member is formed so that it has a substantially constant peripheral length about the perimeter of any cross-sectional plane perpendicular to the longitudinal axis of the spring flexure member. The heat shrinkable tube must be selected in size and shrinkage characteristics to tightly envelope and shrink against the gage and spring flexure member and seal the gage completely to prevent moisture of any kind from getting into contact with the gage. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is related to the following copending applications filed concurrently herewith: Ser. No. 10/680,053, entitled GRAVEL PACK COMPLETION WITH FLUID LOSS CONTROL AND FIBER OPTIC WET CONNECT; and Ser. No. 10/680,440, entitled GRAVEL PACK COMPLETION WITH FIBER OPTIC MONITORING. The disclosures of these related applications are incorporated herein by this reference.
BACKGROUND
The present invention relates generally to equipment utilized and operations performed in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides a downhole fiber optic wet connect and gravel pack completion.
It would be very desirable to be able to use a fiber optic line to monitor production from a well, for example, to monitor water encroachment, identify production sources, evaluate stimulation treatments and completion practices, etc. It is known to use fiber optic lines to transmit indications from downhole sensors, to communicate in the downhole environment and to use a fiber optic line as a sensor.
However, fiber optic lines may be damaged in operations such as gravel packing, expanding tubulars downhole, etc. For this reason, it would be beneficial to be able to replace portions of a fiber optic line downhole, or to install a substitute fiber optic line. This replacement operation would be more economical if a completion string did not have to be retrieved from a well to replace/install the fiber optic line.
Furthermore, it is sometimes desirable to complete a well in sections or intervals, for example, where a horizontal well is gravel packed in sections, or where zones intersected by a vertical well are separately gravel packed. In these cases, it would be beneficial to be able to connect separate sections of fiber optic line to each other downhole, so that the fiber optic line may be installed in sections along with the corresponding sections of the completion.
SUMMARY
In carrying out the principles of the present invention, in accordance with an embodiment thereof, a system is provided which permits fiber optic connectors to be connected downhole. Using this system, separate portions of fiber optic line may be installed in a well, and then operatively connected to each other. Furthermore, a fiber optic line previously installed in a well can be replaced, without having to pull a production tubing string out of the well.
In one aspect of the invention, a system for making fiber optic connections in a subterranean well is provided. The system includes a fiber optic connector positioned in the well. Another fiber optic connector is operatively connected to the first fiber optic connector after the first fiber optic connector is positioned in the well.
In another aspect of the invention, a system for making fiber optic connections in a subterranean well includes an assembly positioned in the well, the assembly including a fiber optic connector. Another assembly is positioned in the well which includes another fiber optic connector. An orienting device orients the assemblies relative to each other, thereby aligning the fiber optic connectors.
In yet another aspect of the invention, a method of making fiber optic connections in a subterranean well is provided. The method includes the steps of: positioning an assembly in the well, the assembly including a fiber optic connector; positioning another assembly in the well which includes another fiber optic connector; orienting the assemblies in the well, thereby aligning the fiber optic connectors; and then operatively connecting the fiber optic connectors in the well.
In a further aspect of the invention, an apparatus for making a fiber optic connection in a subterranean well is provided. The apparatus includes an outer housing having a sidewall, and a passage extending through the housing. A fiber optic connector is positioned in the housing sidewall. Another fiber optic connector is received within the passage. The fiber optic connectors are operatively connectable after the apparatus is positioned in the well.
In a still further aspect of the invention, a system for making fiber optic connections in a subterranean well includes a packer assembly having an orienting device and a fiber optic connector. A tubular string of the system includes another orienting device and another fiber optic connector. The orienting devices align the fiber optic connectors for operative connection therebetween when the tubular string is engaged with the packer in the well.
In yet another aspect of the invention, a system for making fiber optic connections in a subterranean well is provided. The system includes a tubular string having a passage formed through the tubular string, and a fiber optic connector and an assembly received in the passage, the assembly having another fiber optic connector.
A further aspect of the invention includes a method of monitoring a subterranean well. The method includes the steps of: positioning a fiber optic line in the well, the fiber optic line extending in a formation intersected by the well; positioning another fiber optic line in the well, the fiber optic line extending to a remote location; operatively connecting the fiber optic lines while the fiber optic lines are in the well; and monitoring a well parameter using a sensor operatively coupled to the fiber optic line extending in the formation.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1–4 are successive schematic partially cross-sectional views of a system and method embodying principles of the present invention;
FIGS. 5A & B are enlarged cross-sectional views of a fiber optic wet connect apparatus embodying principles of the present invention;
FIGS. 6A & B are cross-sectional views of the wet connect apparatus of FIGS. 5A & B with a fiber optic probe engaged therewith;
FIG. 7 is a schematic partially cross-sectional view of another system and method embodying principles of the invention; and
FIGS. 8–11 are successive schematic partially cross-sectional views of yet another system and method embodying principles of the invention.
DETAILED DESCRIPTION
Representatively illustrated in FIGS. 1–4 is a system 10 and method which embody principles of the present invention. In the following description of the system 10 and other apparatus and methods described herein, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used only for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention.
The system 10 and method are used to demonstrate how the principles of the invention may provide various benefits in a well monitoring application. However, it should be clearly understood that the principles of the invention are not limited to use with the system 10 and method depicted in FIGS. 1–4 , but are instead adaptable to a wide variety of applications. Therefore, the details of the system 10 and method of FIGS. 1–4 , or of any of the other systems and methods described herein, are not to be taken as limiting the principles of the invention.
As depicted in FIG. 1 , a gravel packing assembly 12 has been positioned in a wellbore 14 which intersects a formation or zone 16 . All or part of the gravel packing assembly 12 may be positioned in a cased or uncased portion of the wellbore 14 .
The assembly 12 includes a well screen 18 and a gravel pack packer 20 . The packer 20 is set in the wellbore 14 , and the annulus between the well screen 18 and the wellbore is packed with gravel 22 , using techniques well known to those skilled in the art. A fluid loss control device 24 may be used to prevent fluid in the wellbore 14 from flowing into the formation 16 after the gravel packing operation.
As depicted in FIG. 2 , a tubular string 26 , such as a production tubing string, is conveyed into the wellbore 14 and engaged with the gravel packing assembly 12 . Seals 28 carried on the tubular string 26 sealingly engage a seal bore 30 of the assembly 12 , such as a polished bore of the packer 20 .
The tubing string 26 includes a generally tubular housing assembly or receptacle 32 . A fiber optic line 34 extends from a remote location (not shown), such as the earth's surface or another location in the well, to a fiber optic connector 36 located in the housing assembly 32 .
As used herein, the term “fiber optic connector” is used to indicate a connector which is operably coupled to a fiber optic line so that, when one fiber optic connector is connected to another fiber optic connector, light may be transmitted from one fiber optic line to another fiber optic line. Thus, each fiber optic connector has a fiber optic line operably coupled thereto, and the fiber optic lines are connected for light transmission therebetween when the connectors are connected to each other.
Although in the following description of the system 10 and associated method only one fiber optic line 34 is specifically described, it is to be clearly understood that any number of fiber optic lines may be used in the system and method, and any number of connections between fiber optic lines may be made downhole in keeping with the principles of the invention. For example, in a seismic application, there may be approximately 12 or more fiber optic lines 34 connected downhole.
In addition, other types of lines may be used in conjunction with the fiber optic line 34 . For example, hydraulic and electrical lines may be connected downhole along with the fiber optic line 34 . These other types of lines may be connected downhole using the same connectors as the fiber optic line, or other additional connectors may be used.
The tubing string 26 may also include a packer 38 which is set in the wellbore 14 to secure the tubing string. Note that the fiber optic line 34 extends longitudinally through the packer 38 . Alternatively, the packer 38 could be positioned below the housing 32 , in which case the fiber optic line 34 may not extend through the packer.
In FIG. 3 , a conveyance 40 is used to transport another assembly 42 into an inner passage 44 extending through the tubing string 26 and housing 32 . Representatively, the conveyance 40 is a coiled tubing string, but any other conveyance, such as wireline, slickline, segmented tubing, etc., may be used if desired.
The assembly 42 includes a running tool 46 and a probe 48 . The probe 48 has a fiber optic line 50 extending longitudinally within, or external to, a perforated tubular member 52 attached to the running tool 46 . The fiber optic line 50 is operatively coupled to another fiber optic connector 54 . As discussed above, more than one fiber optic line 50 may be used in the system 10 , and other types of lines (such as hydraulic and/or electrical) may be used and connected using the connectors 36 , 54 .
When the probe 48 is appropriately positioned in the housing 32 , the probe is rotationally oriented relative to the housing, so that the fiber optic connectors 36 , 54 are aligned with each other, and the probe is anchored in place relative to the housing. In this position, the fiber optic line 50 extends longitudinally within the gravel packing assembly 12 .
Pressure is applied via the coiled tubing string 40 and through the running tool 46 to the housing 32 , causing the fiber optic connector 36 to displace toward the fiber optic connector 54 . The fiber optic connectors 36 , 54 are, thus, operatively connected. The fiber optic line 50 may now be used to monitor one or more parameters of the well environment.
For example, the fiber optic line 50 may be configured to sense temperature along its length. It is well known to those skilled in the art that a fiber optic line may be used as a distributed temperature sensor. By positioning the fiber optic line 50 longitudinally within the gravel packing assembly 12 , the fiber optic line can sense temperature distribution along the wellbore 14 as fluid flows from the formation 16 therein. An influx of water from the formation 16 into the wellbore 14 may be located by monitoring the temperature distribution along the gravel packing assembly 12 using the fiber optic line 50 .
As depicted in FIG. 4 , the running tool 46 has been removed from the well, leaving the probe 48 anchored in the passage 44 , and with the fiber optic connectors 36 , 54 connected. The connector 36 is shown in FIG. 4 as having been rotated relative to the housing 32 into engagement with the other connector 54 . However, it should be clearly understood that either of the connectors 36 , 54 may be displaced in any manner in order to bring the connectors into operative engagement.
The probe 48 as depicted in FIG. 4 has an optional fiber optic line 56 which extends external to the tubular member 52 . This demonstrates that the fiber optic lines 50 , 56 may be located in any position on the probe 48 . In addition, separate internal and external sensors 58 , 60 , 62 are connected to the fiber optic lines 50 , 56 , demonstrating that the lines themselves are not necessarily sensors in the system 10 . Sensors 58 , 60 , 62 may be used to sense any well parameter, such as pressure, temperature, seismic waves, radioactivity, water cut, flow rate, etc.
If the fiber optic lines 50 , 56 or sensors 58 , 60 , 62 should fail, or different sensors need to be installed, or if for any other reason it is desired to retrieve the probe 48 , the system 10 provides for convenient retrieval. The running tool 46 is again conveyed into the wellbore 14 and is engaged with the probe 48 . Pressure is applied through the running tool 46 to the housing 32 to retract the fiber optic connector 36 out of engagement with the other fiber optic connector 54 , the probe 48 is released from the housing 32 , and the running tool and probe are retrieved from the well.
Representatively illustrated in FIGS. 5A & B is a specific embodiment of the housing assembly 32 . Of course, the principles of the invention are not limited to the details of this specific embodiment. Instead, many different forms of the housing 32 may be used, if desired. For example, the housing assembly 32 described below utilizes pressure to displace and operatively connect the fiber optic connectors 36 , 54 , but it will be readily appreciated that a fiber optic connector may be displaced mechanically, electrically, magnetically, etc., and other means may be used to operatively connect fiber optic connectors, in keeping with the principles of the invention.
The housing assembly 32 includes an orienting device 64 depicted as a helical profile having a vertically extending slot at a lower end thereof. This orienting device 64 is shown merely as an example of a variety of orienting devices which may be used. Any type of orienting device may be used in keeping with the principles of the invention. A latching profile 66 in the passage 44 is used to secure the probe 48 in the housing 32 . Any type of securing means may be used in keeping with the principles of the invention.
Two fluid passages 68 , 70 communicate with the inner passage 44 . The passage 70 is in communication with an upper side of a piston 72 reciprocably received in a sidewall of the housing 32 . Pressure applied to the passage 70 will bias the piston 72 downward. The other passage 68 is not completely visible in FIG. 5A , but it is in communication with a lower side of the piston 72 , so that pressure applied to the passage 68 biases the piston to displace upward.
The fiber optic line 34 extends through an outer conduit 76 to the housing assembly 32 . The conduit 76 may be, for example, tubing such as control line tubing, or a protective enclosure for the fiber optic line 34 , etc. A seal 78 seals between the housing 32 and the conduit 76 .
The fiber optic line 34 extends through the piston 72 to the fiber optic connector 36 positioned at a lower end of the piston. As the piston displaces downward in response to pressure applied to the passage 70 , the connector 36 is also displaced downward, along with the conduit 76 which displaces through the seal 78 .
As noted above, more than one fiber optic line 34 may be connected downhole using the connectors 36 , 54 , in which case the multiple fiber optic lines may extend through the piston 72 to the fiber optic connector at the lower end of the piston. Furthermore, other types of lines (such as hydraulic and/or electrical) may extend to the connector 36 .
Referring now to FIGS. 6A & B, the housing assembly 32 is representatively illustrated after the probe 48 has been installed and secured in the passage 44 . The running tool 46 (not shown in FIGS. 6A & B, see FIG. 3 ) is releasably attached to the probe 48 at a latching profile 80 when the probe 48 is installed in the housing assembly 32 , and when the probe is retrieved from the housing assembly.
The probe 48 includes an orienting device 82 depicted in FIG. 6A as a lug engaged with the orienting profile 64 . This engagement rotationally orients the probe 48 relative to the housing assembly 32 , so that the fiber optic connector 54 carried on the probe is radially aligned with the fiber optic connector 36 in the housing sidewall 74 . Again, any other means of orienting the probe 48 relative to the housing assembly 32 , and any other means of aligning the connectors 36 , 54 , may be used in keeping with the principles of the invention.
A series of collets 84 are engaged in the profile 66 . A sleeve 86 is displaced downwardly by the running tool 46 when it is desired to anchor the probe 48 in the passage 44 of the housing assembly 32 . The sleeve 86 inwardly supports the collets 84 , preventing their disengagement from the profile 66 . When it is desired to retrieve the probe 48 from the housing assembly 32 , the sleeve 86 is displaced upwardly, thereby permitting the collets 84 to displace inwardly when the probe is retrieved. Again, any other means of securing the probe 48 in the housing assembly 32 may be used in keeping with the principles of the invention.
A series of longitudinally spaced apart seals 88 on the probe 48 straddle the passages 68 , 70 . The probe 48 has openings 90 , 92 which correspond to the respective passages 68 , 70 . The upper opening 90 is in communication with the passage 68 , whereas the opening 92 is in communication with the passage 70 .
In this configuration, pressure may be applied via the opening 92 to the passage 70 , and then to the upper side of the piston 72 to displace it downwardly. Pressure may alternatively be applied via the opening 90 to the passage 68 , and then to the lower side of the piston 72 to displace it upwardly. Thus, the connectors 36 , 54 may be alternately connected and disconnected by applying pressure to corresponding alternate ones of the openings 90 , 92 .
If multiple fiber optic lines 34 are coupled to the connector 36 , and multiple fiber optic lines 50 are coupled to the connector 54 , then the application of pressure to the piston 72 may operate to alternately connect and disconnect these multiple fiber optic lines. If other types of lines are also, or alternatively, coupled to the connectors 36 , 54 , then these other types of lines may be connected and disconnected by application of pressure to alternating sides of the piston 72 .
The running tool 46 includes the plumbing associated with directing pressure to the appropriate openings 90 , 92 . It will be appreciated that, when the probe 48 is to be installed in the housing assembly 32 , the running tool will be configured to apply pressure to the opening 92 , and when the probe is to be retrieved from the housing assembly, the running tool will be configured to apply pressure to the opening 90 .
Referring additionally now to FIG. 7 , another system 100 and method embodying principles of the present invention is representatively illustrated. The system 100 is similar in many respects to the system 10 described above, and so similar elements are indicated in FIG. 7 using the same reference numbers.
Instead of installing the probe 48 in the tubing string 26 after installing the tubing string in the well and engaging it with the gravel packing assembly 12 , in the system 100 the probe 48 is secured in the tubing string 26 at the time the tubing string is installed in the well. The probe 48 is initially secured in the tubing string 26 with a latching device 102 . After the tubing string 26 is engaged with the gravel packing assembly 12 , the latching device 102 is released, permitting the probe 48 to displace downwardly into operative engagement with the housing assembly 32 .
The latching device 102 could be released, for example, by applying pressure to the tubing string 26 , to thereby pump the probe 48 into the housing assembly 32 . This application of pressure could also serve to orient the probe 48 relative to the housing assembly 32 (aligning the fiber optic connectors 36 , 54 ), anchor the probe relative to the housing assembly (such as, by displacing the sleeve 86 downward to support the collets 84 ) and displace the connector 36 into operative engagement with the connector 54 .
Alternatively, a running tool conveyed by coiled tubing, wireline or slickline, etc. could be used if desired to displace the probe 48 into engagement with the housing assembly 32 , and/or to retrieve the probe from within the housing assembly. Any means of displacing the probe 48 in the passage 44 may be used in keeping with the principles of the invention.
As with the system 10 described above, multiple fiber optic lines may be connected and disconnected downhole using the connectors 36 , 54 , and other types of lines (such as hydraulic and/or electrical) may be connected and disconnected downhole using the connectors in the system 100 .
Referring additionally now to FIGS. 8–11 , another system 110 and method embodying principles of the invention is representatively illustrated. As depicted in FIG. 8 , a gravel packing assembly 112 is installed in a wellbore 114 opposite a formation or zone 116 intersected by the wellbore. The gravel packing assembly 112 includes a well screen 118 and a gravel pack packer 120 .
Gravel 122 is placed in the annulus formed between the screen 118 and the wellbore 114 using techniques well known to those skilled in the art. A fluid loss control device 124 may be used to prevent loss of fluid into the formation 116 from the wellbore 114 .
The gravel packing assembly 112 is similar in many respects to the gravel packing assembly 12 used in the system 10 described above. However, the gravel packing assembly 112 used in the system 110 also includes an orienting device 126 , a fiber optic line 128 and a fiber optic connector 130 . These additional elements permit the fiber optic line 128 to be connected to other fiber optic lines subsequently installed in the wellbore 114 .
The orienting device 126 may be similar to the helical profile and vertical slot of the orienting device 64 used in the housing assembly 32 described above. Other types of orienting devices may alternatively be used, if desired.
The fiber optic line 128 is operatively coupled to the fiber optic connector 130 . From the fiber optic connector 130 , the fiber optic line 128 extends through the packer 120 and longitudinally downward adjacent the screen 118 . However, it should be understood that the fiber optic line 128 may extend internally, externally or within a sidewall of the screen 118 . Preferably, the fiber optic line 128 extends longitudinally across the formation 116 intersected by the wellbore 114 , so that a parameter of fluid flowing between the formation and the wellbore may be monitored along the length of the intersection between the formation and the wellbore.
As depicted in FIG. 9 , another gravel packing assembly 132 is installed in the wellbore 114 and engaged with the gravel packing assembly 112 . Preferably, the gravel packing assembly 132 is secured to the gravel packing assembly 112 when the assemblies are engaged with each other, such as by using collets engaging an internal profile as described above, etc.
As the gravel packing assembly 132 is installed, it is rotationally oriented relative to the gravel packing assembly 112 , so that the fiber optic connector 130 is aligned with another fiber optic connector 134 carried at a lower end of the gravel packing assembly 132 . This rotational orientation is facilitated by an orienting device (not visible in FIG. 9 ) of the gravel packing assembly 132 engaging the orienting device 126 of the gravel packing assembly 112 . For example, the gravel packing assembly 132 may have a lug thereon similar to the orienting device 82 of the probe 48 described above.
The fiber optic connector 134 is operably coupled to a fiber optic line 136 extending to another fiber optic connector 138 at an upper end of the gravel packing assembly 132 . The fiber optic line 136 extends through a gravel pack packer 140 and longitudinally adjacent a well screen 142 of the gravel packing assembly 132 . The screen 142 is positioned opposite another formation or zone 144 intersected by the wellbore 114 .
As with the fiber optic line 128 , the fiber optic line 136 preferably extends along the intersection between the formation 144 and the wellbore 114 , so that it may be used to sense a parameter of fluid flowing between the formation and the wellbore along the length of the intersection. The fiber optic line 136 may be positioned externally, internally or within a sidewall of the screen 142 . Each of the fiber optic lines 128 , 136 may be used with one or more separate sensors connected thereto (such as the sensors 58 , 60 , 62 described above), and/or portions of the fiber optic lines may serve as sensors.
It may now be fully appreciated that the system 110 provides for convenient downhole interconnection of the fiber optic lines 128 , 136 of the gravel packing assemblies 112 , 132 . Using the principles of the invention, it is not necessary to install a single continuous fiber optic line in a well to monitor separate portions of the well. Instead, separate fiber optic lines may be installed, and then connected downhole. This is very beneficial where, as in the system 110 , different portions of the well are separately completed, gravel packed, etc. This is of particular benefit in highly deviated or horizontal wellbores where productive intervals are separately completed, or intervals are completed in separate sections.
In the system 110 as depicted in FIG. 9 , gravel 146 is placed in the annulus between the screen 142 and the wellbore 114 . Note that seals 148 carried at a lower end of the gravel packing assembly 132 sealingly engage a seal bore of the packer 120 of the gravel packing assembly 112 . When the gravel packing operation is completed, a fluid loss control device 150 may be used to prevent loss of fluid from the wellbore 114 into the formations 116 , 144 .
The gravel packing assembly 132 includes another orienting device 152 at an upper end thereof. The orienting device 152 may be similar to the orienting device 64 described above.
As depicted in FIG. 10 , the orienting device 152 is used to rotationally orient a tubular string 156 including a housing assembly 154 relative to the gravel packing assembly 132 , so that the fiber optic connector 138 is aligned with another fiber optic connector 158 carried at a lower end of the housing assembly. Preferably, the tubular string 156 is secured to the gravel packing assembly 132 when the tubular string is engaged with the gravel packing assembly, such as by using collets engaging an internal profile as described above, etc.
The fiber optic connector 158 is operatively coupled to another fiber optic line 160 extending to a remote location, such as the earth's surface or another location in the well. The fiber optic line 160 extends through a packer 162 interconnected in the tubular string 156 , and generally extends external to the tubular string. However, the fiber optic line 160 could be otherwise positioned, such as internal to the tubular string 156 or in a sidewall of the tubular string, in keeping with the principles of the invention.
The housing assembly 154 may be substantially similar to the housing assembly 32 described above, with the addition of the fiber optic connector 158 and fiber optic line 160 . For example, the housing assembly 154 includes the fiber optic connector 36 and fiber optic line 34 described above. As the housing assembly 154 is engaged with the gravel packing assembly 132 , an orienting device (such as the orienting device 82 ) on the housing assembly engages the orienting device 152 on the gravel packing assembly, thereby rotationally aligning the fiber optic connectors 138 , 158 . Seals 164 carried on the housing assembly 154 sealingly engage a seal bore of the packer 140 .
Thus, as depicted in FIG. 10 , the fiber optic connectors 130 , 134 are operatively connected and the fiber optic connectors 138 , 158 are operatively connected. This permits the fiber optic lines 128 , 136 , 160 to transmit optical signals therebetween which, in turn, permits monitoring of well parameters along the intersections between the wellbore 114 and the formations 116 , 144 .
Unfortunately, the installed fiber optic sensors, lines, etc. could possibly malfunction or become damaged. In that event, the system 110 provides for a backup fiber optic sensing system to be installed, without the need for pulling the tubular string 156 from the well. Instead, a probe 166 (similar to the probe 48 described above) is installed in the housing assembly 154 .
As depicted in FIG. 11 , the probe 166 is conveyed into a passage 168 extending through the tubular string 156 , the housing assembly 154 and the gravel packing assemblies 112 , 132 . The probe 166 may be conveyed into and through the passage 168 by any type of conveyance and it may be displaced by pressure or another biasing means. The probe 166 may be installed in the passage 168 either before or after the tubular string 156 is installed in the wellbore 114 .
The probe 166 is engaged with the housing assembly 154 and rotationally oriented relative thereto, for example, by using orienting devices 64 , 82 as described above. This rotational orientation aligns the fiber optic connector 36 with the fiber optic connector 54 carried on the probe 166 . The probe 166 is anchored in the housing assembly 154 , for example, using the collets 84 and sleeve 86 as described above.
The fiber optic connector 36 is displaced into operative engagement with the fiber optic connector 54 , for example, using pressure applied via the running tool 46 as described above. The fiber optic connector 54 is operatively coupled to the fiber optic line 50 which, in the system 110 , extends external to the tubular member 52 and longitudinally through the gravel packing assemblies 112 , 132 .
The fiber optic line 50 may now be used to sense parameters of fluid flowing from the formations 116 , 144 into the wellbore 114 along the length of the intersections of the wellbore with the formations. Thus, the fiber optic sensing capabilities of the system 110 have been restored by installing the probe 166 , and without the necessity of retrieving the tubular string 156 , or either of the gravel packing assemblies 112 , 132 , from the well. This feature of the system 110 is particularly beneficial if the screens 118 , 142 are expanding screens, since expansion of the screens could cause damage to the fiber optic lines 128 , 136 and/or associated sensors.
As with the system 10 described above, the probe 166 is separately retrievable from the well, in case a portion of the probe malfunctions or becomes damaged in the well. Thus, the invention provides a fiber optic sensing system which may be retrieved and replaced without pulling a completion string from the well. This retrievability and replaceability is enhanced by the use of fiber optic connectors 36 , 54 which may be oriented, aligned and connected downhole. The other fiber optic connectors 130 , 134 , 138 , 158 permit the well to be completed in sections without the need to install a single continuous fiber optic line for monitoring parameters of fluid in the wellbore 114 .
As with the systems 10 , 100 described above, multiple fiber optic lines may be connected and disconnected downhole using the connectors 36 , 54 , 130 , 134 , 138 , 158 , and other types of lines (such as hydraulic and/or electrical) may be connected and disconnected downhole using the connectors in the system 110 .
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are contemplated by the principles of the present invention. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents. | A downhole fiber optic wet connect and gravel pack completion. In a described embodiment, a system for making fiber optic connections in a subterranean well includes a first fiber optic connector positioned in the well and a second fiber optic connector operatively connected to the first fiber optic connector after the first fiber optic connector is positioned in the well. A method of monitoring a subterranean well includes the steps of: positioning a fiber optic line in the well, the fiber optic line extending in a formation intersected by the well; positioning another fiber optic line in the well, the fiber optic line extending to a remote location; operatively connecting the fiber optic lines while the fiber optic lines are in the well; and monitoring a well parameter using a sensor operatively coupled to the fiber optic line extending in the formation. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to current-fed resonant inverters for electrical power applications to change direct current (DC) into alternating current (AC). One application of the invention is with power supplies for inductive power transfer (IPT) systems.
BACKGROUND
[0002] Inverters have numerous applications in electrical power supplies including the production of alternating current power supplies, for example, when used as an inverter to convert a DC voltage into an AC voltage supply (e.g. an uninterruptible power supply). They may also be used in internal stages of DC to DC converters, induction heating, microwave generation, surface detection, medical experimentation, high frequency radio systems, IPT systems, etc.
[0003] A circuit schematic for a known push-pull current fed resonant inverter is shown in FIG. 1 . The operation of such inverters is discussed in U.S. Pat. No. 5,450,305 the contents which are incorporated herein by reference. These resonant inverters have gained much popularity due to their low switching losses and low electromagnetic interference (EMI).
[0004] In IPT Systems the IPT power supply is ideally a fixed frequency power supply producing a fixed frequency sinusoidal output voltage. Such a power supply is shown in FIG. 1 . The circuit of FIG. 1 has a DC inductor L DC , a split phase transformer L PS , and a parallel resonant tank circuit C 1 L 1 . Switches S 1 and S 2 operate in anti-phase to produce a resonant voltage across the parallel tuned tank circuit. Diodes in series with the switches are added so that there is no possibility of the switches turning on at the same time and discharging C 1 .
[0005] The inductor L DC provides a constant DC current source under steady state operating conditions. This inductor is usually designed to be large to overcome saturation problems. The phase splitting transformer with the two closely coupled windings L SP is used to divide the DC current into two branches, and the switches S 1 and S 2 are controlled to be “on” and “off” alternately, to change the direction of the current that is injected into the resonant tank circuit which comprises the coil L 1 and its tuning capacitor C 1 . The resistor R represents the load supplied by the inverter.
[0006] An external controller (not shown) is also required in order to control the switches S 1 and S 2 . The controller detects the resonant voltage (for example sensing the voltage across tuning capacitor C 1 ) and drives the switches at zero voltage crossings (Zero Voltage Switching). These switching techniques help to reduce the switching losses and EMI. To do so, an extra voltage transformer or winding is usually needed to detect the zero voltage crossings across the capacitor C 1 . The detected information is used by the controller to drive the switches S 1 and S 2 and special gate drive circuits are usually required. The start-up of this form of inverter is relatively difficult, requiring a complex controller.
[0007] When operating at high frequencies a conventional power supply (not shown) has problems since as the frequency gets higher it becomes increasingly difficult to operate the supply as the required dV/dt and dl/dt transients are so high that operating the power supply is problematic. For example at a frequency of 140 kHz a complete cycle is only 7 microseconds so that if the switches switch on a 480V bus in 1% of a half cycle then the dV/dt on the switches is 480/(3.5 microseconds×1%)=13.7 kV/microsecond which is a very fast transient that makes the operation of high-side switches challenging. The circuit of FIG. 1 avoids this problem with soft switching and low dl/dt and dV/dt. However a difficulty with this circuit ( FIG. 1 ) is maintaining an operating frequency in response to changes in the reactive load on the inverter and in particular maintaining a required power factor since the circuit can easily bifurcate.
BRIEF SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an inverter or a power supply or a method of operating an inverter or power supply which at least obviates one or more of the foregoing disadvantages or which will at least provide the public with a useful choice.
[0009] According to a first aspect there is provided a resonant inverter including an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source; a first switching means comprising two switching devices operable in substantially opposite phase to alternately switch current from the power source into the inductive elements; and a second switching means to selectively switch one or more control capacitances into or out of the resonant circuit dependent on a power factor of the resonant circuit.
[0010] The first switching means such as S 1 and S 2 above switch on alternate half-cycles at the resonant frequency. The second switching means switch capacitors across the switching devices of the first switching means to change the tuning frequency of the inverter.
[0011] Such an arrangement may be used to reduce high peak voltages in the resonant circuit that may otherwise occur due to lack of tuning or low power factor. The presence of such high peak voltages, especially at high frequency where the rate of change in voltage would then be very high, can damage the switching devices. Tuning the inverter also optimises the power transferred for example in an IPT (inductive power transfer) secondary such as an electric vehicle. Selective switching of the control capacitors enables dynamic correction of the power factor which may vary due to external factors such as secondary load changes and/or coupling changes, for example due to a changing distance between the inductive elements and a secondary coil on an electric car.
[0012] In an embodiment, the second switching means comprises a switching device and a control capacitance connected in parallel with each of the switching devices of the first switching means. The second switching means may be arranged to switch the control capacitance into or out of the resonant circuit at zero current crossings of the tuning capacitance where changing the frequency of the inverter allows the power factor to be adjusted.
[0013] In an embodiment the resonant inverter further comprises a power factor detection circuit arranged to determine the power factor by determining the phase difference between the current of the resonant circuit and the switching signal for driving the switching devices.
[0014] In an embodiment the power factor detection circuit comprises a current transformer coupled to the resonant circuit and an integrating capacitor, a squarer coupled across the integrating capacitor, and a comparator for comparing the output of the squarer with the switching signal.
[0015] In an embodiment, individual or groups of a plurality of control capacitances are arranged to be selectively switched into or out of the resonant circuit in selected cycles of the resonant circuit to control the operation of the inverter. A series of control capacitances of different sizes may be combined by appropriate second switching means in order to get the circuit capacitance required to correct the determined power factor during the dynamic operation of the inverter
[0016] In an embodiment, the resonant inverter further comprises a third switching means comprising two switching devices each connected to a control resistor and operable in substantially opposite phase to alternately switch current from the power source into the inductive elements, the first switching means being switched into or out of the resonant circuit in order to start or stop the resonant circuit. This arrangement provides a means to start and stop the resonant inverter the third switching means is operable all the time and the first switching means switches on when full power is required to bypass the control resistors.
[0017] In an embodiment, the resonant inverter may comprise a buck control circuit coupled between an input current source and the inductive elements, the buck control circuit having a diode and buck control switch having a duty cycle which is controlled in order to adjust the voltage across the tuning capacitor. This arrangement may be used to start and stop the resonant current, and may also be used to reduce the peak voltage when the resonant circuit is not tuned. This development offers better control options and additionally can be implemented with only three switches making this a cheap option.
[0018] There is also provided a method of operating a resonant inverter having an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source, first switching means comprising two switching devices and second switching means; the method comprising: switching the two switching devices in substantially opposite phase to alternately switch current from the power source into the inductive elements; and switching the second switching means to selectively switch one or more control capacitances into or out of the resonant circuit dependent on a power factor of the resonant circuit.
[0019] The embodiments can provide a fixed frequency sinusoidal resonant inverter comprising using a digitally switchable power capacitor whereby the tuning frequency can be closely controlled to be near to the operating frequency at all times and the circuit operates at high efficiency with low distortion waveforms such that the switching voltage and the output current have a high power factor under steady state and dynamic conditions.
[0020] According to a second aspect there is provided a resonant inverter including an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source; a first switching means comprising two switching devices operable in substantially opposite phase to alternately switch current from the power source into the inductive elements; and a buck control circuit coupled between the input and the inductive elements, the buck control circuit having a diode and buck control switch having a duty cycle which is controlled in order to reduce the voltage across the tuning capacitor in response to an over voltage condition.
[0021] The over voltage condition may be a pre-determined voltage threshold which can be measured directly or inferred from other parameters such as power factor.
[0022] This arrangement can also be used to reduce high peak voltages in the resonant circuit due to lack of tuning or low power factor. It can be implemented simply with a total of three switching devices comprising the first switching means of two transistors and the Buck switching means comprising one transistor, and is very low cost. Thus the duty cycle of the Buck switching means is controlled in order to reduce the DC supply voltage to the inverter in response to the switching of the first switching devices being out of phase with the resonant circuit resonating current. Alternatively or additionally, the duty cycle may be controlled in order to stop or start the resonant circuit.
[0023] There is also provided a method of operating a resonant inverter having an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source, first switching means comprising two switching devices and a buck control circuit coupled between the input and the inductive elements, the buck control circuit having a diode and buck control switch second switching means; the method comprising: controlling a duty cycle of the buck control switch in order to control the voltage across the tuning capacitor in response to an over voltage condition or when starting and stopping.
[0024] In an embodiment the method comprises determining a voltage or power factor of the resonant circuit and controlling the duty cycle depending on the determined voltage or power factor.
[0025] The embodiments can provide a fixed frequency resonant inverter that operates at high efficiency with constant frequency but without tuning and errors are accommodated within the circuit but without high distortion or significant losses and the circuit can be shut down when required without damage.
[0026] According to a third aspect there is provided a resonant inverter including an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source; a first switching means comprising two switching devices operable in substantially opposite phase to alternately switch current from the power source into the inductive elements; and a third switching means arranged to selectively switch a control resistance into or out of the resonant circuit in order to start or stop the resonant circuit.
[0027] Switching the control resistor into or out of the resonant circuit reduces or increases the resonant voltage to allow a controlled change between normal resonant operation and OFF, without large transient voltages being incurred that could damage the switching devices.
[0028] This arrangement can be used with or without the second switching means of the aspects described above.
[0029] In an embodiment the third switching means comprises two switching devices each connected to a control resistor and operable in substantially opposite phase to alternately switch current from the power source into the inductive elements. The third switching means may be selectively switched out of the resonant circuit when not starting or stopping the resonant circuit. In an embodiment the two transistors of the third switching means continue to be switched selectively out of phase to drive the resonant circuit when starting or stopping.
[0030] According to a fourth aspect there is provided a resonant inverter including an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source; a first switching means comprising two switching devices operable in substantially opposite phase to alternately switch current from the power source into the inductive elements; a second switching means to selectively switch a control capacitance into or out of the resonant circuit to thereby change the resonant frequency of the resonant circuit; the switching devices arranged to change a switching frequency dependent on the selective switching of the second switching means.
[0031] This arrangement allows for selecting different operating frequencies of the resonant inverter. Switching control capacitances into and out of the resonant circuit changes the resonant frequency, and by controlling the switching frequency of the switching devices to match, the operating frequency of the resonant inverter can be selected for a particular application. Also operation at a slightly different frequency alters the phase relationship over time so that the power factor can be controlled. The other aspects noted above may then be used to control starting/stopping and tuning or power factor.
[0032] In an embodiment the second switching means comprises a switching device and a control capacitance connected in parallel with each of the switching devices of the first switching means.
[0033] In an embodiment the second switch means is arranged to switch the control capacitance into the resonant circuit at zero current crossings of the tuning capacitance.
[0034] In an embodiment the inverter further comprises a zero-voltage detection circuit having a current transformer coupled to the resonant circuit and an integrating capacitor, and a squarer coupled across the integrating capacitor.
[0035] In an embodiment individual or groups of control capacitances of a plurality of control capacitances are arranged to be selectively switched into or out of the resonant circuit in selected cycles of the resonant circuit to control the operation of the inverter.
[0036] In another aspect the invention consists in a resonant inverter including an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source, a first switching means to controllably switch current from the power source into the resonant circuit, and a second switching means to selectively switch a control capacitance into or out of the resonant circuit to thereby change the natural resonant frequency of the resonant circuit.
[0037] In an embodiment the second switching means switches the control capacitance into the resonant circuit on voltage zero crossings of the tuning capacitance.
[0038] In an embodiment the second switch means switch the control capacitance into the resonant circuit at zero current crossings of the tuning capacitance.
[0039] The first switching means may comprise two switching devices operable in substantially opposite phase to alternately switch current from the power source into the inductive elements.
[0040] The second switching means may comprise a switching device connected in parallel with each of the switching devices of the first switching means, and a control capacitance being connected therebetween.
[0041] In an embodiment a plurality of second switch means and associated control capacitances are provided.
[0042] In an embodiment individual or groups of, control capacitances of a plurality of control capacitances can be selectively switched into or out of the resonant circuit in selected cycles of the resonant circuit to control the operation of the inverter over time. Thus the control capacitances can in some embodiments be connected or disconnected intermittently, or dithered to control the operation or characteristics of the resonant circuit over a plurality of cycles of operation of the resonant circuit.
[0043] In an embodiment power factor measurement means are provided which measure the power factor by comparing the current in the tuning capacitance with the switching control waveform(s) for the first switching means.
[0044] In an embodiment control means are provided which use the measured power factor to control the second switching means to change the power factor toward a desired power factor.
[0045] In another aspect the invention consists in a resonant inverter including an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source, a first switching means to controllably switch current from the power source into the resonant circuit, and a second switching means to selectively switch a control resistance into or out of the resonant circuit to thereby change the Q factor of the resonant circuit.
[0046] In an embodiment the control resistance is chosen to provide near critical damping to the resonant circuit.
[0047] The first switching means may comprise two switching devices operable in substantially opposite phase to alternately switch current from the power source into the inductive elements.
[0048] The second switching means may comprise a switching device connected in parallel with each of the switching devices of the first switching means, and a control resistance being connected therebetween.
[0049] In another aspect the invention consists in an IPT power supply including an inverter according to any one of the preceding statements.
[0050] In another aspect the invention consists in a method of operating a resonant inverter, the method comprising selectively switching a control capacitance into or out of the resonant circuit of the inverter to control the frequency or phase or power factor of the inverter.
[0051] In an embodiment the method includes switching the control capacitance into the resonant circuit on voltage zero crossings.
[0052] In an embodiment the method includes switching the control capacitance into the resonant circuit at current zero crossings.
[0053] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention as set forth in the accompanying claims and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications be included within the present invention.
[0054] Throughout this document the word “comprise” and variations such as “comprises” and “comprising” is intended to be interpreted in an inclusive sense.
DRAWING DESCRIPTION
[0055] FIG. 1 : is a schematic circuit diagram of a known push pull current fed resonant inverter,
[0056] FIG. 2 : is a circuit diagram of another known inverter,
[0057] FIG. 3 : is a diagram of one embodiment an inverter according to the present invention,
[0058] FIG. 4 : is a diagram of a detection circuit according to one aspect of the invention,
[0059] FIG. 5 : is a diagram of another embodiment an inverter according to the present invention,
[0060] FIG. 6 : is a diagram of a power factor measurement circuit according to one aspect of the invention,
[0061] FIG. 7 : is a diagram of another embodiment an inverter according to the present invention,
[0062] FIG. 8 : is a diagram of another embodiment an inverter according to the present invention,
[0063] FIG. 9 : shows inverter waveforms.
DETAILED DESCRIPTION
[0064] Inverters are basic building blocks for many modern power inverters. The new inverters described in this document can be used in various applications where high frequency voltage or current generation is required. These applications include but not limited to inductively coupled contactless power transfer, induction heating, DC-DC converters, uninterruptible power supplies for example.
[0065] The invention will now be described, beginning with an explanation of a known inverter which is shown in FIG. 2 . This circuit is essentially the same as that in FIG. 1 but now there is no phase splitting transformer and two coupled inductors 205 and 206 are used instead. There is also no independent resonant inductor—the same inductors 205 and 206 perform this task as well. In both these circuits FIG. 1 and FIG. 2 switching the transistors in response to the natural oscillations of the circuit can cause bi-furcation on critical loads and then the power available to the IPT system is greatly reduced. The ideal operation of the circuit is quite simple. Transistors 200 and 201 are switched on and off in a complementary (push-pull) fashion. When 100 is ON the voltage at point B is low (ideally ground— 209 ) and point A follows a half-sinewave voltage at the resonant frequency determined by the inductances 105 and 206 in series resonating with capacitor 204 . When the voltage at A returns to ground switch 201 is turned ON, switch 200 is turned OFF and point B executes a half cycle. And so the process continues. If the system is perfectly tuned then 200 and 201 can be driven by a clock signal to keep the resonance going with the two switching devices 200 and 201 operating in substantially opposite phase to alternatively switch current from the power source 208 into the inductive elements. In practice perfect tuning is not practical so diodes 202 and 203 are added so that if the switches operate out of synchronism with the resonance, high circulating currents cannot flow through the switches and destroy them. In the practical operation of the circuit points A and B are only pulled to ground if diodes 202 and 203 are ON when switches 200 and 201 are ON respectively.
[0066] If the circuit is operating under no-load conditions this may not be the case and then the operation may be slightly compromised. Thus ideally the circuit should be operated on-load and with a fixed frequency.
[0067] In some applications there are significant advantages with the use of this circuit. Double D pick-up pads as described in international patent publication WO2010090539 have two coupled coils which can be used here (i.e. 205 and 206 ) as part of the power supply—and as part of the pick-up—saving the cost and space of separate inductor. The circuit has no transformer isolation but for an in-pad power supply it is not needed, and the circuit can self-tune. So when it is used in an in-pad situation as the air-gap or the alignment varies the pick-up can keep retuning the pad at about 1000 times per second or more. In this way any VAR load on the pick-up or power supply is significantly minimised.
[0000] A Power Supply with Two Operating Frequencies
[0068] A new circuit is shown in FIG. 3 which can operate at 2 different frequencies.
[0069] Referring to FIG. 3 , two extra capacitors 304 A and 304 B are added using switches 310 A and 310 B. Both of these switches have internal body diodes that can conduct in the reverse direction. When point A goes high in a semi-sinewave way with switch 310 A on while point B is low then capacitor 304 A is charged and discharged on that ½ cycle so that in essence capacitor 304 A is in parallel with capacitor 204 . Similarly on the next ½ cycle with switch 304 B ON, when point B goes high capacitor 304 B is charged and discharged and capacitor 304 B is in parallel with capacitor 204 . Thus while switches 310 A and 310 B are ON capacitor 204 has a capacitor in parallel with it switched at each ½ cycle and the circuit will be resonant at a different frequency than it was before. Thus operation of the secondary switches 310 A and 310 B switch in or out control capacitances 304 A and 304 B thereby changing the resonant frequency of the inverter. At the same time the clock frequency driving the switches 200 , 201 , 310 A, 310 B is adjusted to match the new resonant frequency in order to restore tuning the clock frequency will need to be reduced. The tuning and switching or clock frequency can be switched very rapidly—whenever capacitor 204 is at zero volts switches 310 A and 310 B can be changed. The switches can be operated together as only one of them has voltage at any particular time, or they can be operated independently whenever the capacitor 204 is at zero voltage. The main switches 200 and 201 may not switch at exactly the point where capacitor 204 changes sign if the circuit is not operating at precisely unity power factor but the extra switches 310 A and 310 B switch on the zero crossing of capacitor 204 .
[0070] Measuring the voltage crossings on capacitor 204 is not trivial as the voltage changes sign at relatively high speed. However an elegant way to measure it is shown in FIG. 4 . Here a current transformer is used to detect the current in capacitor 204 . The output from the current transformer is a current source that charges capacitor 402 —thus the voltage across capacitor 402 is the integral of the current through capacitor 204 —which from first principles is the voltage across capacitor 204 . The zero crossings of capacitor 402 are therefore the correct times to operate the switches 310 A and B which can be switched on for the exact half cycles that they are needed for by squaring the 402 capacitor voltage and adding an inverter. Resistor 403 adds a very slight phase lead to the zero crossing detection circuit. This phase lead allows for the propagation delays in the gates driving the switches. A phase lead of 5 degrees at 140 kHz for example would correct for a propagation delay of 97 ns which is likely to be the approximate delay that would be experienced. The circuit may be trimmed by adjusting resistor 403 to get the delay as precise as possible.
[0000] A Power Supply with Multiple Output Frequencies
[0071] By adding extra capacitors and switches the power supply of FIG. 3 can be converted to FIG. 5 that can operate over a relatively wide range of precise frequencies.
[0072] The number of switches required to get a range of frequencies may be greatly reduced if the extra capacitors are weighted in a sequence. For example with 4 switches (on each side) weighted 1:2:4:8 any capacitor size from 1-15 may be selected. The number of capacitors and switches may be reduced further by ‘dithering’ the switches on alternative cycles. Thus capacitors can be selectively switched in or out in groups or individually in cycles that may be selected over time (i.e. over a plurality of cycles of the resonant circuit) so that over time, or on average, a desired output or behaviour of the resonant circuit is achieved. A capacitor with a weight of 3 switched alternatively with one of 4 gives an equivalent weight of 3½—or three capacitors with weights of 1:2:4 can be dithered to give: 0, ½, 1, 1½, 2, 2½, 3, 3½, 4, 4½, 5, 5½, 6, 6½, 7 giving 15 selectable values with 3 capacitors. As noted all the ½ steps are achieved by alternating the value with the next step up—5½ is 5 alternated with 6 which is 4+1 alternated with 4+2, or 3½ is 1+2 alternated with 4. All the switchings are done at zero voltage so the disruption to the circuit is minimal.
[0073] The circuit of FIG. 5 can be used to produce multiple possible output frequencies and may be used to set different operating frequencies for inductive power transfer (IPT) applications for example. Thus a single device may be used to provide different operating frequencies depending on circumstances and/or the secondary devices into which they are transferring power. Typically an operating frequency will be set and then maintained constant for a particular application or secondary device. However should the application or secondary device change then the primary resonant inverter may be re-set to a different operating frequency in the manner described above.
[0074] In an alternative embodiment, the resonant inverter circuits of FIGS. 3 and 5 may be operated to produce one frequency but correct any VAR errors by switching in or out one or more control capacities 304 A, 304 B, 504 A 1 - 504 AN, 504 B 1 - 504 BN. Referring to FIG. 9 , the voltage wave forms at points A and B are shown for unity power factor, a lagging power factor, and a leading power factor respectively. The switching instants of switches 200 and 201 are shown, and with a unity power factor these coincide with the zero voltages of the wave forms at point A and point B as shown. Operating the resonant inverter in tune or close to unity power factor enables maximum power transfer and also minimises the voltage across the switching transistors 200 or 201 when these are ON, thereby reducing any current flowing through these transistors and hence minimising potential damage.
[0075] However in practice the tuning or power factor of the inverter can change dynamically due to changes in secondary loading or coupling, for example due to changing distance between the primary and secondary coils. If the resonant circuit is not perfectly tuned, the resonant current leads or lags the switching instants as shown, which can lead to large peak voltages across the switching transistors 200 or 201 especially as the power factor moves closer to zero. Combined with high frequency operation, the change in voltage across the switching transistors 200 or 201 is significant especially as the power factor moves away from unity. Combined with high frequency operation, the change in frequency across the switching transistors must be limited and if it is not otherwise controlled can destroy or damage the switching transistors. The same considerations also apply for the secondary switches 310 A, 310 B, 510 A 1 - 510 AN, 510 B 1 - 510 BN which are switched together with their corresponding first switching device 200 or 201 as described above. For example the peak voltage at point A is π multiplied by the supply voltage 208 —thus where the supply voltage is 300V, the peak voltage is 942V. However if the inverter is not tuned, the peak voltage at point A or point B is now the supply voltage multiplied by π/cos(θ). Here θ is the phase angle between the resonant current and switching waveform. Thus the peak voltage can become very large as e approaches 90°—for example for a power factor of 0.05 (5%), the peak voltage for a supply voltage of 300V is in excess of 10 kV and cannot be sustained.
[0076] The control capacitances can be switched in or out of the inverter circuit of FIG. 5 in order to tune the resonant circuit, moving the power factor closer to unity and reducing peak voltages and hence voltage transients across the switching transistors. An improved power factor also maximises the power transferred to a secondary device even given dynamically changing coupling and/or load conditions. Thus the resonant inverter can be controlled in order to selectively switch one or more control capacitances into or out of the resonant circuit depending on the power factor of the resonant circuit. As described previously with respect to the multiple frequency embodiments, the control capacitances are preferably switched into or out of the inverter circuit at the zero voltage crossings at points A and B respectively. Determination of the capacitor voltage zero crossings can be implemented using the circuit of FIG. 4 as previously described for example.
[0077] For this self-tuning of the circuit it is necessary to dynamically measure the power factor so that the circuit can be operated with unity power factor even if the circuit parameters change. As noted the ideal voltage waveform in this circuit has a phase that is the same as the clock signals driving the switches 200 and 201 . The circulating current through capacitor 204 is already available as the output of the circuit of FIG. 4 , converted into a square wave, and if the circuit is perfectly tuned then we require these two square wave signals to be perfectly in phase. In practice it is easier to measure phase differences when the signals have an ideal phase angle between them of 90 degrees rather than zero. Here a new voltage reference can easily be produced—the clock signals for switches 200 and 201 must be supplied by a microprocessor or FPGA using a crystal source and it is trivial to get an additional output frequency shifted by 90 degrees with respect to the signals that drive the switches. Furthermore, if required, this signal can have its phase slightly advanced or retarded to correct for propagation delays in the circuitry.
[0078] A circuit for measuring the power factor is shown in FIG. 6 using a current transformer 401 . Not all of the current is measured—only the current in capacitor 204 —but as this is typically 70-80% of the total current this is sufficient for the control purpose here as only the phase of the current is used and not the magnitude. As shown in FIG. 6 the output from current transformer 401 is integrated by capacitor 402 and squared by amplifier 601 . The microprocessor controlling the whole power supply now produces an alternative square wave output at a 90 degree phase angle relative to the switch gate waveforms—conceptually shown here by the circuit element 603 . The outputs of 602 and 603 are multiplied by an exclusive or gate: If the inputs to the X-OR gate are in phase (condition A) the output will be typically 12 V corresponding to the power supply for the X-OR gate, if they are at 90 degrees (the ideal situation) the output will switch at twice the resonant frequency (condition B), and if the inputs are at 180 degrees then the output will be continuously low (C). It is a simple matter to measure the outputs and determine the phase angle. In practice a digital technique is easy to use here. Over a period where a counter could count a maximum of say 1000 counts, if the counter input is gated by the output of the X-OR in case A it will count 1000 counts, in case B it will count 500, and in case C it will count zero. Furthermore the output may be scaled so that it counts to how many capacitor switches need to be ON to tune the circuit by counting 0-15 corresponding to the 1:2:4:8 capacitor selection shown in FIG. 5 .
[0079] A simple set up for this is to choose capacitor 204 in FIG. 5 to supply 80% of the capacitance required. Then if the extra capacitance is made up with 4 switches and capacitors 1:2:4:8 giving 1-15 corresponding here to 2½% steps, then 8 steps adds 20% giving ideal tuning at 100% capacitance, 0 steps is tuning at 80% capacitance (the inductance values are high), and 15 steps is tuning at 115% (the inductance values are low), and the counting system will provide all the steps in between. More resolution is achievable with more steps or dithering the switchings. This tuning can be done very quickly—less than 1 ms. The system can be made into a PI controller by measuring the error and algebraically adding the error to the present number of steps to give the fastest possible response to achieve full tuning, yet be responsive to changes. It will be seen that the inverter topologies described can be tuned so well that the diode between each switch 200 , 201 and tuning capacitor 204 may not be required. Furthermore, the second switches 310 A, 310 B etc. will naturally turn off.
Starting and Shut-Down
[0080] The circuit described in FIGS. 3 and 5 is relatively difficult to stop and to start—especially with a fixed clock frequency. These problems may be alleviated by adding another pair of switches with resistors in series with them as shown in FIG. 7 . To start the circuit switches 200 , 201 are left OFF and switches 700 , 701 are switched at the correct frequency with the correct DC supply voltage. Resistors 702 , 703 are chosen to gives the circuit near critical damping—perhaps 0.8 times critical to give 1% overshoot. The circuit will reach full voltage very quickly whereupon the regular switches can be enabled and 700 , 701 can be turned off.
[0081] Alternatively these second switching means may be kept running as the voltages across resistors 702 , 703 are zero so now no power is wasted. If this option is chosen then shutting the circuit down simply requires removing gate signals to 200 , 201 when they have no voltage across them, thereby forcing the circuit currents to flow through resistors 702 , 703 where energy is taken from the circuit and resonance collapses. Capacitor 204 is still in circuit and the resonant current can still flow through this so that only the real (power) circuit flows through the resistors. The completion of the shutdown is to leave all of the transistors off, ready for another start as required.
[0082] In another arrangement, if the circuit is at full power (and the control resistors are switched off) stopping the circuit or performing a shut-down in the case of a resonant voltage that is too high for the safety the switches may be implemented as follows. When one first switch is on—say 200 —switch ON 701 (the opposing third resistor means switch), then switch ON 700 —ie the resistor switches in parallel with 200 . Keeping 201 OFF, then switch OFF 200 and either keep the resistor switches ON to shut down the circuit, or alternatively switch 700 and 701 using the first switching means clock or control signals so that the circuit is now being driven through resistors and cannot resonate so that the voltages in it will stabilize at the supply voltage. The voltage across 200 will rise but stay below 1100 V. The circuit will stabilize with all capacitors at the DC supply voltage.
[0083] The operation of all of these circuits with respect to voltage control is that the resonant tank voltage will increase until the DC voltage across inductor 207 is stable with only DC current in the inductor. Under these conditions the AC rms voltage across capacitor 204 is the DC voltage 208 times
[0000]
π
2
[0000] so for a 300 V DC supply the AC capacitor voltage will be 666 V AC rms. If the inductor 207 is not used the same numerical value still obtains. It is the high output voltage that is a feature of this circuit and here that is shown clearly in that the output voltage of 666 V AC is generated from a 300 V DC supply.
Soft Starting and Stopping, and Over-Voltage Control
[0084] An alternative method for stopping and starting is shown in FIG. 8 . Here the supply to the inverter circuit itself is through inductor 207 (this inductor is still optional and if it is not used then the feed is through inductors 205 and 206 in parallel) and the switch 801 operates with a duty cycle D such that the average voltage across the diode 802 is the input voltage 208 times the duty cycle D of the switch 801 . This circuit is a Buck controller and is well known but here a current output is taken so that the component count is minimised. The circuit can be started with D at essentially zero and then ramped up to full voltage by sweeping D over the range 0 to 1. In practice 208 is typically 300V and the equivalent output voltage can be swept over the range 0 to 300 V by linearly changing D. The same sweep in reverse may now be used to switch the circuit off by reducing D to zero. In practice ramping up and down can be relatively quick and transitions in the order of 100 microseconds or less are easily achievable.
[0085] The duty cycle D of the buck control circuit can also be controlled in order to adjust the voltage across the tuning capacitor in other circumstances, and in particular to reduce the voltage in response to an over voltage condition where the resonant circuit is out of tune or has a non-unity power factor. As discussed above, when the resonant circuit is out of tune, the resonant current is leading or lagging the switching waveform which can result in large peak voltages across the switching transistors and at high frequency very large voltage transients which can cause damage.
[0086] The operating voltages of the basic circuit shown in FIG. 2 are the drain voltages for transistors 200 and 201 corresponding to the points labelled A and B on FIG. 2 . These voltages are shown for a short sequence on FIG. 9 where the upper waveform is for perfect tuning and the lower waveforms are for leading and lagging power factor respectively. The waveforms A and B are the actual voltages that would be observable with a CRO and are synchronous with the switching instants of the transistors. If the circuit is perfectly tuned the switching instants and the zero crossings of the resonant tank are identical but if the circuit is not perfectly tuned they are not identical but the tank circuit leads or lags the switching instants as shown. Under perfect conditions the average voltage at point A is the peak voltage times
[0000]
1
π
[0000] and this must equal the DC voltage input 208 so that the peak voltage is π times VDC and if VDC is 300 V the peak voltage is 942 Volts. But if the circuit is not perfectly tuned but there is an angle θ between the capacitor tuning current and the switching waveforms then the average voltage at point A or B is the peak voltage times cos(θ)/π.
[0087] Thus with the same averaging as before the peak voltage is now VDC times π/cos(θ) and can become very large if θ approaches 90 degrees. The method of tuning using capacitors as shown in FIG. 5 can be used to tune the circuit and eliminate this problem. But the buck converter may also be used with an un-tuned circuit—VDC may be modified (reduced) by controlling the duty cycle D of the buck circuit switch 801 . The peak voltage can now be contained within the ratings of the transistors. This is a very low cost arrangement using only three switches. In most cases the amount of mistuning will be less than 10-20 degrees corresponding to a power factor of 0.94 or better and the degree of modification of D is less than 10% but it is achieved at low cost with no extra tuning components. Note that the same control function is effective for both leading and lagging conditions. As e approaches 90 degrees the circuit will be protected but the power output will be reduced—if the power must be maintained then the circuit of FIG. 5 —or equivalent—can additionally or alternatively be used.
[0088] The circuit of FIG. 8 combined with the circuit of FIG. 2 gives a resonant power supply that is easily and cheaply controlled. All the protection features are achieved using the Buck controller and the circuit can drive leading and lagging power factors without difficulty and with high efficiency at high frequencies. The transistors may be kept switching all the time so that whenever power is applied the circuit will process it and output inverter waveforms and in particular has the ability to operate at high frequency without restrictions on dl/dt and dv/dt.
[0089] The duty cycle D of the buck controller can be controlled by adjusting the switching of device 801 in response to the power factor determined from the resonant circuit, for example using the circuit of FIG. 5 . Alternatively the voltage at point A or point B may be measured using for example the circuit of FIG. 4 without squaring amplifier 404 . As the voltage exceeds a pre-determined threshold, the duty cycle D is reduced in order to maintain the resonant voltages within predetermined bounds.
[0090] The various embodiments described above may be employed together a single resonant inverter circuit, or may be deployed separately depending on the requirements of the power supply requirement.
[0091] It will be appreciated that the invention described with reference to FIG. 7 allows the Q factor of the resonant circuit to be controlled, and may be applied to other inverter circuits than those disclosed in this document. | This invention relates to current-fed resonant inverters for electrical power applications to change direct current (DC) into alternating current (AC). One application of the invention is to power supplies for inductive power transfer (IPT) systems. There is provided a resonant inverter including an input for supply of current from a DC power source, a resonant circuit including two coupled inductive elements and a tuning capacitance, the inductive elements being arranged to split current from the power source; a first switching means comprising two switching devices operable in substantially opposite phase to alternately switch current from the power source into the inductive elements; and a second switching means to selectively switch one or more control capacitances into or out of the resonant circuit dependent on a power factor of the resonant circuit. | 7 |
BACKGROUND TO THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to sewing thread and its manufacture and, more particularly, to the manufacture of what is known as “textured thread”.
[0003] 2. Description of Related Art
[0004] One of the basic elements of manufacture of sewing thread is what is referred to in the art as “yarn”. A simple yarn is produced by combining single fibres or filaments. One way of combining fibres is by applying a twist to them, known as a singling twist (since there is but a single group of fibres that are being twisted together). The application of a twist to filaments to produce a yarn is not essential, however, and fibres may also be combined without doing so. The characteristics of the fibres which are combined to form the yarn play a significant role in the eventual characteristic of a sewing thread for whose manufacture, ultimately, such yarns are used; as do the characteristics of the yarns themselves.
[0005] Yarns can be manufactured from a variety of fibres, such as staple fibres which are lengths of fibre; and continuous filaments which are typically made of artificial material by processes such as melt-spinning. Threads are created by ‘plying’ together two or more yarns by twisting the yarns around each other.
[0006] One particular kind of thread is known as “textured thread”. This is produced from yarn which has had a ‘texture’ applied to it subsequent to the individual filaments being combined with each other. Texturing can be achieved by, for example, directing an air jet at the yarn shortly after the filaments produced by melt-spinning exit the melt-spinning apparatus (i.e. when it is still soft and susceptible to disruption) or by what is known as “false twisting”. False twisting is a process in which the combined filaments are first twisted and set in that condition by heat (typically steam heat), following which they are then once again untwisted. False twisted yarn has no twist, but a ‘memory’ in the filaments which make up the yarn, introduced by the heating process, nonetheless causes them to behave as if they were twisted. Textured yarn and thread manufactured from textured yarn therefore both have, as a result of this characteristic, a relatively soft ‘handle’ (i.e. feeling to touch) relatively high bulk (i.e. low density) and high elongation (i.e. longitudinal elasticity under tension). Textured thread therefore tends to be of use in certain areas of garments where soft seams are required. It has the advantage of being inexpensive to manufacture primarily because relatively inexpensive raw materials are used. However, its characteristics make it a difficult thread to work with because of its susceptibility to cause sewing faults such as snagging, looping and breaking during sewing operations. Further, it has relatively low strength. Accordingly, textured thread is unsuitable for wider applications, such as apparel stitching (i.e. stitching of panels of fabric to construct garments).
SUMMARY OF THE INVENTION
[0007] A first aspect of the present invention lies in an appreciation of the ability to employ textured thread more widely in circumstances where the above-mentioned problems can be overcome. According to a first embodiment of the present invention, textured thread is manufactured by plying yarns having a zero or near-zero twist, the twist imparted to the plied yarns being substantively greater than that previously thought to be acceptable in a textured thread.
[0008] A further aspect of the present invention provides a method of producing a textured thread. Yet a further independent aspect of the present invention provides a method of apparel stitching using textured thread having the characteristics of an embodiment of textured thread according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments of the present invention will now be described, by of example, and with reference to the accompanying drawings in which:
[0010] FIG. 1 is a schematic illustration of a melt-spinning apparatus for producing continuous filaments and continuous filament yarn;
[0011] FIG. 2 is a detail of FIG. 1 ;
[0012] FIG. 3 is FIG. 2 is a schematic illustration of a further step in the manufacturing process of textured filament yarn;
[0013] FIGS. 4A and 4B are illustrations of thread manufacture from multi-ply yarn;
[0014] FIG. 5 is a flow chart of the steps involved in the manufacture;
[0015] FIG. 6 is a schematic section through a twisting apparatus employed in an embodiment of the present invention;
[0016] FIG. 7 is a table showing characteristic parameters of thread produced according to embodiments of the present invention; and
[0017] FIG. 8 is a table showing parameters of preferred embodiments of method according to the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] Referring now to FIG. 1 , continuous polyester filaments for the production of yarn are manufactured by means of a melt spinning apparatus 10 . Polymer chips are placed into a hopper 12 from which they descend into a heated cavity 14 where they are melted. Subsequently, a pump 16 forces the molten polymer 18 , under pressure. into a chamber 19 having, in the present example, four spinneret drums 20 a to 20 d . Referring now additionally to FIG. 2 , each spinneret drum comprises a plurality of fine apertures 24 , through which the molten polymer is extruded to create filaments 30 from which yarn can be constructed. Where it is desired to manufacture continuous filament yarn, the filaments are 30 combined to create a yarn 32 which is then wound on to a bobbin 40 . The combining can be performed in one of a number of ways. In one example, interfilament adhesion is achieved by bringing the filaments into proximity with each other and then applying an air jet to the filaments to cause intermittent points of the filaments into contact with each other. An alternative is to draw the filaments via a heated godet (a special kind of guiding roller) and, simultaneously, applying a low-level of twist to the filaments using, for example, conventional ring spinning techniques. The combining operation is shown schematically as occurring ‘downstream’ of the extrusion from the spinneret 20 A. Whereas spinneret 20 a produces continuous filaments, spinnerets 20 b to 20 d, in the illustrated example, are adapted for generating staple fibres and so deposit their filaments into cans 42 a to 42 c from which the filaments are subsequently processed.
[0019] Referring now to FIG. 3 , the continuous filament yarn is then unwound from the bobbin 40 and passed through suitably configured guide and pinch rollers 44 , 46 in order to stretch the yarn, whereupon it is wound, relatively loosely, onto filament bobbin ready for use by a thread manufacturer.
[0020] The continuous filament yarn whose manufacture has thus far been described is also known as a flat filament yarn, mimicking to some degree the characteristics of silk filaments and is entirely conventional.
[0021] Referring now to FIGS. 4A and 4B , yarn supplied on the cheese can then be spun into a thread suitable for use in sewing in a number of ways. For example, 3 individual yarns may be ‘plied’ together in the manner illustrated in FIG. 4A in order to create, in the present example, a 3-ply sewing thread. It will be noted, from FIG. 4A , that the filaments of the yarn are twisted in an anticlockwise direction (known as Z twist) where as the yarns are twisted together in a clockwise direction (known as S wist) with the level of twist in each component stage being carefully calculated to produce a stable sewing thread in the final composite product. Alternatively, referring now to FIG. 4B , two yarns may be plied together and then two or more such plied yarns are plied into a corded thread. These are merely two examples offered to provide the reader with an opportunity to assimilate the terminology used at various stages in the manufacturing process, and other combinations and permutation of these manufacturing techniques may be applied to produce different configurations of thread. Thus far, the processes described are entirely conventional processes.
[0022] As mentioned previously, it is known to produce “textured” yarn which, in turn, may then be used to manufacture ‘textured’ sewing thread. One way in which textured yarn is manufactured is by imparting high pressure air to the yarn formed of continuous filaments. The air serves to disrupt the regularity of the yarn before it has entirely cooled, thereby to impart the requisite “texture” to it. Another manner of providing a texture is to impart what is known as a false twist. The continuous filament yarn is first twisted and then is set into that condition by steam heat; thereafter, it is once again untwisted. The result is that the final twist in the yarn is zero but the filaments of the yarn have a memory of their original, twisted configuration (hence the term ‘false’ twist). This false twist causes the individual filaments within the yarn to tend to twist, loop and snarl within its body thereby resulting in a relatively soft and bulky yarn having the requisite textured properties. Referring once again to FIG. 1 , where textured yarn is produced by the ‘false twisting’ process the filaments 30 will typically (though not necessarily) be initially combined by means of the ring spinning operation. Where textured yarn is produced by applying an air jet then the combining of the filaments 30 may advantageously be achieved by this technique also.
[0023] Traditionally, thread manufactured of textured yarn, although having desirable properties of high bulk and high levels of elongation (that is to say elastic longitudinal expansion under tension) and a soft handle, has proved to be unsuitable for the majority of uses such as apparel sewing (that is to say the joining of fabric panels as part of a manufacture of a garment). Typically, reasons for this include low relative strength of such thread, together with a tendency to cause sewing defects such as breaking during sewing, snagging within the machine, skipping a stitch or the bobbin chase failing to catch the thread properly.
[0024] The inventors of the present invention have observed that the limitations on the use of textured threads arise, inter alia, from the characteristic of limited cohesion between individual filaments of the textured yarn from which the thread is made. Such limited cohesion allows the fibres of the yarn to open up and/or separate from each other during sewing. This, in turn, can result in broken filaments and may even result in total failure of the thread as a whole. The inventors have realised that it is possible to apply twist levels to textured yarn which are greater than those in the prior art and therefore serve to avoid the problems which arise from low fibre cohesion; yet, at the same time, maintain a sufficiently low degree of twist within the yarn to enable yarns to be plied together at a sufficiently low counter-torque (i.e. acting antagonistically to the torque applied by the twist in the individual yarns) that the resultant thread retains the desirable characteristics of textured thread. Further, the inventors have appreciated that, in processing the yarns to make this new textured thread, the tensions which are applied are preferably sufficiently low to avoid elongating the yarns to such an extent that the resultant, plied thread takes on more of the characteristics of traditional, flat filament yarn which lacks the bulk and soft handle of textured thread. This ‘squaring of the circle’, previously considered to be impossible, results in textured thread which is suitable for needle sewing and therefore can be used for apparel stitching, where previously this was not thought to be possible.
[0025] Referring now to FIG. 5 , an outline of the process by which thread according to embodiments of the present invention is manufactured will now be described. At step 510 the cheese of false-twist textured singles yarn is unwound. At step 512 the singles yarn is then stretched and has a twist imparted to it whereupon. For finer thread sizes, this step is followed immediately by the plying step 514 , typically with both the twisting step 512 and the plying step 514 being performed on a single, “2 for 1” twisting machine.
[0026] Alternatively, for heavier thread sizes, two separate steps are typically performed. Thus, the stretch and twist step 512 is then followed at step 516 by winding of the twisted singles yarn onto a spool (usually known as a ‘pirn’). Thereafter, the two or more singles yarns are then plied together at step 518 on a separate machine. In either case, both plying steps 514 or 518 are followed by a further winding step 520 of the resultant griege thread. The griege thread is then dyed at step 522 in the conventional manner used for other polyester yarns, that is to say autoclaving for natural white thread, and conventional package dyeing for other colours. The dyed thread has lubricant applied to it in the conventional manner and is lubricated and finish wound onto a user package at step 524 .
[0027] Referring now to FIG. 6 , one manner of achieving step 512 in the method of FIG. 5 is shown. A textured yarn 610 is wound onto a bobbin 612 which is, in turn, adapted to rotate about an axis A. The yarn 610 is drawn off the bobbin 612 and routed through the bobbin spindle 614 about which the bobbin 612 can rotate. The yarn 610 thus passes around the outside of the bobbin and, via a guide hook 616 . Rotation of the bobbin as the yarn 610 is drawn off it causes the fibres of the yarn to acquire a twist, with the degree of twist being determined by the relative speed of linear travel of the yarn as it is drawn off the bobbin to the speed of rotation of the bobbin. Where the size of the twisted singles yarn is such as to require twisting and plying on separate machines, the twisted yarn is then wound onto a pirn 618 ready for plying.
[0028] The twist imparted to the yarn at step 512 is lower than that which is typically applied to continuous, flat filament yarn. It has been found that applying such levels of twist causes the resultant thread to exhibit very few, if any textured characteristics, or to a very small degree. Accordingly, the levels of twist applied are greater, than those applied in conventional textured thread manufacture but lower than those applied when creating thread from continuous, flat filament yarn.
[0029] Conventionally, textured thread is manufactured by plying several textured filament yarns together. Typically, the yarns are given very low amounts of twist; typically in the region of ½ to 1 turn per inch; the degree of twist imparted upon plying multiple yarns together to create thread is necessarily related to that twist level (in order for the plied thread to have a neutral overall torque, or at least a stable construction) and so is correspondingly low. Conventional wisdom has consistently held that it is not possible to impart any greater levels of twist to create textured thread for a variety of reasons, amongst which is the belief that doing so causes the thread manufactured from textured filament yarn to lose the very characteristics for which it is used in the first place.
[0030] According to an embodiment of the present invention, textured continuous filament yarn is spun into a sewing thread which is then capable of being used for apparel stitching and other, similar uses previously thought improper in textured thread. An embodiment of the present invention produces a textured thread suitable for sewing is manufactured by a method which comprises the steps of: creating a continuous filament yarn having a false twist thereby imparting texture to the yarn; imparting a further twist in the range of between 5.5 and 18.7 turns per inch to the false twisted continuous filament yarn, the twist being in a first rotational direction; generating a thread by plying two or more textured continuous filament yarns with each other in a second rotational direction, and having a twist within the range 3.9 to 17 turns per inch.
[0031] Details of specific values and ranges of twisting and plying combinations for different thread weights (expressed both in terms of denier, tex and decitex parameters) are illustrated in this table both in turns per inch (TPI) and turns per metre (TPM) in FIG. 7 .
[0032] Referring now additionally to FIG. 8 , a further table is shown in which examples of the linear and processing speeds and tensioning employed for manufacture of threads having the characteristics set out in FIG. 7 above are set out. The first set of rows provides details of the parameters for the process step 512 . The second set of rows provides details of the process of step 514 and 520 . Thus the first two rows combined provide parameters for the process route set out in FIG. 5 as including steps 512 , 514 and 520 ; the first, third and fourth sets of rows in combination provide details of the process route in FIG. 5 provided by steps 512 , 516 , 518 and 520 .
[0033] FIG. 8 effectively provides a comparison table, in which the processing of textured polyester thread or yarn as the case may be (TXP) in accordance with embodiments of the present invention is compared to the standard processing parameters used for continuous filament (CF). It can be seen that, in the majority of cases, the speeds at which the TXP is processed is slower than that used in standard processes; and, in addition, that the tensioning of the TXP during processing is also lower. This is counter-intuitive, in that, classically, speeds are desired to be as high as possible in order to produce as much thread in as short a time as possible. Embodiments of the method according to the present invention, however, provide for lower speeds at lower tensions. This ensures that the thread is not ‘debulked’ by the processing which would cause it to lose some of its texture. The tension differences between the processing of standard CF thread and that of TXP in accordance with embodiments of the present invention are expressed in percentages. Thus, for example, a percentage difference of 36% indicates that the TXP thread is processed at 64% of the tension for standard CF thread. The speeds differ from relatively small comparative reductions, such as the case of 5300 reduced from 5600 in the case of plying 18 Tex yarn, the latter being around 94% slower; to 10,500 RPM reduced to 8700, with the latter being around 83% of the standard speed in the case of 45 Tex.
[0034] Textured thread created in this way has a number of advantages. Textured filament yarn is relatively inexpensive as a raw material and its manufactured into textured thread requires relatively fewer manufacturing steps than would be the case for a thread which would be required to perform equivalent functions, such as a corespun thread. Further because lower levels of twist are imparted than for thread made of conventional, flat filament continuous yarn, the thread has a lower profile when used for apparel stitching (which, of course, textured yarn was never previously suitable for). The relatively higher levels of elongation of the resultant thread when compared with conventional continuous flat filament thread is also an advantage when used for the seams of active wear garments, which frequently require a higher stretch due to the character of the fabric employed. | A method of manufacturing textured thread textured thread comprises the steps of: processing textured yarn having a zero or near-zero twist by applying a singles twist thereto; plying at least two textured yarns together by twisting them in a direction opposing the singles twist; wherein the singles twists lie in the range 4 to 20 turns per inch and the plying twist lies in the range 2 to 18 turns per inch. | 3 |
FIELD OF INVENTION
This invention relates to electrical receptacles. In particular, this invention relates to a recessed receptacle for a workstation or table which permits the connection of electrical cables to ports providing remote power supply and/or communications connections.
BACKGROUND OF THE INVENTION
Todays workplace incorporates many kinds of electrical devices, most notably computers (particularly personal computers) and communications facilities such a voice and data transmission lines. A typical workstation will have a computer which may be connected to modem, to a local area network (LAN), to a dedicated or shared printer and/or remote storage devices, intercom, video interface and many other widely available electrical devices that increase productivity and communications capacity in the workplace.
Most such devices require a power supply, and many require communications cables to interface with other local and remote devices. In a permanent workstation the power supply and interface cabling can be installed and bundled, but this tends to be unsightly and can interfere with the efficient use of space in a small workstation. In temporary workstations such as boardroom tables, research cubicles and the like where portable devices (eg. laptop computers, video monitors etc.) are used, it can be cumbersome and time consuming to connect and organize power supply and interface cables for a short period of use.
Permanent floor-mounted receptacles or "floor monuments" are available for such purposes, but they often cannot be conveniently located in anticipation of where such facilities may be required, and they reduce the ability to rearrange office furniture. Receptacles affixed to or recessed into the work surface itself have recently become more popular, but they tend to be difficult to use because the cabling is connected to the receptacle at an angle perpendicular to the work surface and thus protrudes upwardly into the work space. Where a receptacle is recessed accessibility is significantly diminished because the connection ports are often not easily visible and a user must approach the receptacle from directly above it. In a large work surface such as a boardroom table can require that the user lean uncomfortably over the table while attempting to align the cable plug with the compatible port for connection, and the vertical motion required to connect or disconnect a cable is awkward and unnatural making connecting and disconnecting electrical cables physically difficult.
SUMMARY OF THE INVENTION
The present invention overcomes these disadvantages by providing an electrical receptacle adapted to be recessed into a work surface, in which the power supply, communications, video and any other desired ports are disposed at an oblique angle relative to the work surface. Thus, the user has a direct line of sight to the port plate from a normal standing position, and can insert a plug into (or detach a plug from) the appropriate port relatively laterally, which is a more natural motion that facilitates connection or detachment especially where the plug and the port fit very snugly together. Further, because of the oblique angle of the ports the cabling protrudes from the receptacle substantially flush with the work surface, providing a less cluttered appearance and diminishing intrusive interference with the use of the work space.
In the preferred embodiment the invention comprises an exposed compartment for connecting electrical cables to the ports having a cover which closes flush with the work surface and leaves a small gap for the egress of cables from the receptacle, and a concealed compartment isolated from the exposed compartment which contains the electrical ports and wiring in communication with one or more remote devices and/or power supplies. The receptacle of the invention is thus much more accessible from a user's normal working position, and provides a less cluttered and more efficiently organized work space.
The present invention thus provides an electrical receptacle adapted to be recessed into a work surface, comprising a concealed compartment containing ports in electrical communication with at least one remote device or power source, and an exposed compartment for connecting electrical cables to the ports, accessible through the work surface, the ports being mounted on a partition plate isolating the exposed compartment from the concealed compartment, wherein the partition plate is disposed at an oblique angle relative to the work surface.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate by way of example only a preferred embodiment of the invention,
FIG. 1 is a perspective view of a table embodying the invention,
FIG. 2 is a perspective view of an electrical receptacle of the invention with the cover plate open,
FIG. 3 is a side cross-section of the electrical receptacle of FIG. 2 showing the cover plate in closed and open positions, and
FIG. 4 is an exploded perspective view of the electrical receptacle of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a boardroom table 10 having a work surface 12 embodying the invention. The table 10 is provided in suitable locations with receptacles 20 of the invention, recessed into the table preferably such that the receptacles 20 are flush with the work surface 12. The invention will be described with reference to the table 10 shown in FIG. 1, however it will be appreciated that the invention can be equally applied to any other work surface 12, including desks, workstations, cubicles, countertops and the like, and the invention is not intended to be limited to any particular type of work space.
In the preferred embodiment the receptacle 20 comprises an outer housing 22 which houses a concealed compartment 30 containing electrical ports of any desired type, such as standard power supply port 2 and/or communications port 4, and an exposed compartment 40 which is accessible to a user for connecting and disconnecting electrical cables such as a power cable 6 and/or communications interface cable 8 to the respective ports 2, 4. The ports 2, 4 are accessible through the top opening 42 of the exposed compartment 40, which is covered by a hinged cover plate 60 that in the closed position rests substantially flush with the work surface 12.
The receptacle 20 is preferably formed from the following components, illustrated in FIG. 4: A front portion 20a; a rear portion 20b which interlocks with the front portion 20a along a slip-fit interlock 31, a partition plate 50, the cover plate 60 and end plates 23. The various components of the receptacle 20 are preferably extruded, for example from aluminum, plastic or any other suitable material permitted by local electrical codes. However, the receptacle 20 of the invention may also be formed from sheet material or cast, moulded or otherwise manufactured and the invention is not intended to be limited thereby.
As shown in FIG. 3, the ports 2, 4 are mounted in conventional fashion on a partition plate 50 which isolates the exposed compartment 40 from the concealed compartment 30. The partition plate 50 is provided with openings suitable for accommodating the ports 2, 4, and extends fully between the end plates 23 of the receptacle 20. The partition plate 50 is preferably removable, in the embodiment shown being detachably affixed by tabs 51 which snap-fit to a pair of opposing lips 24 projecting from the housing 22.
The partition plate 50 is mounted to the housing 22 at an oblique angle relative to the work surface 12, in the preferred embodiment shown approximately 45°, so that a user can approach the ports 2, 4 from a natural angle when standing in front of the table 10. It will be appreciated that other angles may be appropriate for a particular use, depending for example on how far the receptacle 20 is set back from the edge of the table 10, and the invention is not intended to be limited to the specific angle illustrated. The front end 44 of the exposed compartment 40 preferably approaches the partition plate 50 at approximately a right angle, which facilitates accessibility of the ports 2, 4, provides an attractive appearance and renders the exposed compartment 40 easier to clean.
In the preferred embodiment the exposed compartment 40 thus forms substantially a right-angled triangle in cross-section, with the hypotenuse parallel to and substantially flush with the work surface 12. In the embodiment illustrated the front end 44 of the exposed compartment 40 extends to the work surface, while the housing 22 diverges therefrom and is affixed to the underside of the table at tab or lip 26. For additional reinforcement a web 25 connects the top edge of the front end 44 of the exposed compartment 40 to the housing 22.
The concealed compartment 30 is defined by the housing 22, the partition plate 50 and a wall 32. In the embodiment shown the concealed compartment 30 accommodates a communications port 4 and a power supply port 2, isolated from one another by a divider 34 to form separate power supply and communications compartments 30a, 30b within the concealed compartment 30. The rear wall 28 of the housing 22 is provided with suitable openings 36a, 36b for strain relief sleeves 38a, 38b through which the power supply and communications wiring 7, 9 enter the concealed compartment 30. The rear wall 28 mounts to the underside of the table 10 at tab or lip 27. The dimensions of the concealed compartment 30 and spacing of the divider 34 should meet electrical code requirements for the particular region in which the receptacle 20 is intended to be used, as will be known to those skilled in the art.
The cover plate 60 when closed does not extend fully to the front of the receptacle, leaving a gap 58 through which the connected cables 6, 8 emerge from the receptacle 20 to the various electrical devices (not shown) to which they are connected. The rear of the cover plate 60 is provided with a hinge 64 that mounts about a pivot 62, which is preferably formed on the top edge of the wall 32, allowing the cover plate 60 to swing from the closed position (shown in solid lines in FIG. 3) to the open position (shown in phantom lines in FIG. 3). A flange 66 along the rear of the cover plate 60 is provided with an enlarged edge, which snap-fits under a tooth 68 formed beneath the hinge pivot 62, allowing the cover plate 60 to be locked into the open position. The hinge 64 is designed to abut a ledge 33 formed in the wall 32 when the cover plate 60 is flush with the work surface 12, so that the closed cover plate 60 does not rest against the cables 6, 8.
In use a single receptacle 20 may be employed, for example at a personal workstation or research cubicle, or multiple receptacles 20 may be used as in the table 10 illustrated in FIG. 1. Openings dimensioned to receive the receptacles 20 are cut or otherwise formed through the work surface 12. The receptacle 20 is assembled and the strain relief sleeves 38a, 38b are inserted through the openings 36a, 36b, respectively, in the rear wall 28 of the concealed compartment 30. The receptacle 20 is mounted to the table 10 from underneath and affixed by screws 29 or other suitable fastening members, and electrical wiring 7, 9 from a remote power supply, communications devices etc. (not shown) is inserted through the strain relief members 38 (multiple receptacles 20 may be wired in parallel beneath the table 10). The partition plate 50 is removed and the ports 2, 4 are mounted into their respective openings 52. The required electrical connections between the ports 2, 4 and the wiring 7, 9 are made in conventional fashion, and the partition plate 50 is snap-fitted to the receptacle 20.
To connect a workstation device a user simply lifts the cover plate 60 until it locks in the open position and inserts the plugs for the power supply and/or communications cables 6, 8 into the appropriate ports 2, 4 as required. The user has a direct line of sight to the partition plate from a position standing in front of the table 10, and can insert a plug into the port 2 or 4 using a natural lateral thrusting motion which is similar to that used when plugging a cord into a wall receptacle.
A preferred embodiment of the invention having been thus described by way of example only, it will be apparent to those skilled in the art that certain modifications and adaptations may be made without departing from the scope of the invention, as set out in the appended claims. | An electrical receptacle adapted to be recessed into a work surface, having a concealed compartment containing electrical ports for connection to a remote power supply and communications devices and an exposed compartment for connecting electrical cables to the ports. The ports are mounted on a partition plate isolating the exposed compartment from the concealed compartment, which is disposed at an oblique angle relative to the work surface to facilitate the connection and detachment of electrical cables and reduce clutter in the work space. | 7 |
FIELD OF THE INVENTION
The present invention relates to plain journal bearings, particularly though not exclusively, for internal combustion engines and to so-called overlay coatings deposited upon the running sliding surface of such bearings.
BACKGROUND OF THE INVENTION
Overlay coatings on plain journal bearings are well known. Such coatings are used to improve the running characteristics of plain bearings. Generally, overlay coatings are relatively soft metal alloys having a hardness in the region of about 15 Hv; are frequently based on alloys of lead; and, are deposited on another harder bearing alloy at a thickness in the range from about 10 to 30 μm. Overlay alloys of the type under consideration are usually applied by electro-deposition from aqueous plating solutions.
The bearings on which the overlays are deposited are of generally cylindrical or, more commonly, semi-cylindrical form as half-bearing shells which support the crankshaft journals of internal combustion engines, for example. Such bearings generally comprise a layer of a strong backing material such as steel, for example, on which is bonded a layer of a bearing material frequently chosen from alloys of aluminium or copper. The method of attaching the layer of bearing alloy to the strong backing may be any that is suitable and may include techniques such as pressure welding of sheets of bearing alloy to the backing; the casting of molten alloy onto the backing; or, the sintering of powders of alloy to the backing, for example, these methods not being exhaustive. The overlay alloy coating is deposited on the surface of the harder bearing alloy and endows the finished bearing so formed with properties which include conformability and the ability to embed dirt particles and so prevent scoring of a shaft journal by particles of debris carried in the lubricating oil. Although overlay alloys in their bulk form are relatively weak alloys, they have the ability when applied as a thin layer to another, harder bearing alloy to increase the fatigue strength of a bearing embodying that harder and intrinsically stronger bearing alloy. This is effected due to the conformability of the overlay alloy by being able to deform slightly to accommodate slight mis-alignments, especially in new engines during the “running in” phase, and so spread the load more evenly across the bearing surface area.
As noted above, many conventional overlay alloys are based on alloys of lead. Lead is a toxic metal which will eventually be phased out of use by governmental legislation throughout the world. In order to make the lead-based overlay layer less prone to corrosion in hot engine oils about 10 weight % of tin is frequently added or, alternatively, 7 to 10 wt % of indium. Indium, however, is relatively very expensive compared with tin and tends to be used for more expensive, higher performance vehicles. However, when tin is used in the overlay alloy and is deposited upon a harder bearing alloy such as copper-lead, for example, a problem exists in that the tin under engine operating conditions tends to diffuse out of the overlay into the lead of the underlying bearing alloy, as does indium. This is solved by coating the surface of the underlying, harder bearing alloy with a thin diffusion barrier of about 1–3 μm of a metal such as nickel. However, this is not entirely satisfactory as diffusion still occurs and the overlay still becomes depleted in tin due to the formation of non-equilibrium intermetallic compounds such as Ni 3 Sn or Ni 3 Sn 2 which are not good bearing materials in the situation where the shaft journal wears through the overlay to the underlying interface comprising these intermetallic compounds.
With the ever increasing demands placed on bearings by engines having higher specific outputs and operating at higher engine revolutions, there has been a demand for these relatively soft overlay alloys to have improved wear resistance whilst at least maintaining existing levels of fatigue, cavitation resistance and corrosion resistance. This demand has resulted in the development of so-called lead-tin-copper overlay alloys an example of which is Pb-10Sn-2Cu.
Thus, it is an object of the present invention to provide an overlay layer which is not toxic and a further object is to provide an overlay which does not form undesirable compounds at an interface with an underlying, harder bearing material. A yet further object is to provide an overlay having improved performance over known lead-based overlay alloys.
According to a first aspect of the present invention there is provided a plain bearing having an overlay material layer at a sliding surface of the plain bearing, the plain bearing comprising a layer of a strong backing material, a layer of a first bearing alloy bonded to the strong backing material and a layer of a second bearing alloy comprising said overlay material bonded to said first bearing alloy layer wherein said second bearing material comprises tin having included in the matrix thereof an organic levelling agent.
The tin overlay layer according to the present invention comprises essentially pure tin in that there are no metallic alloying constituents, other than unavoidable impurities, however, the tin is deposited from a bath containing additions of one or more organic materials which have the effect of so-called “levelling” on the electro-deposited tin layer.
Organic materials which have been tested in bearings of the present invention embodying tin overlays include nonylphenolpolyglycolether and pyrocatechol. The content of the organic material in the plating bath has an influence on the degree of levelling achieved in the deposited tin layer, the degree of levelling being reflected in the surface roughness of the tin layer.
At low levels of organic levelling agent, too low for the full benefit of the present invention to be felt, the surface appearance of the bearing surface is one of a generally crystalline appearance having pools of smooth material distributed over the surface. At a content of organic levelling agent where the whole surface is smooth, this is the desirable minimum content.
It is believed that the organic levelling agent is incorporated in the matrix of the deposited tin layer as polymer chains occluded in the matrix structure such as in the form of an organo-metallic tin compound, for example. The polymer chains appear to impart a preferred orientation to the tin atoms during deposition which has been found to give improved slip properties. Improved slip properties have been evidenced by lower coefficients of friction in the tin layer compared with ordinary tin deposits without the levelling additions. The surface of the tin overlay of the bearing of the present invention is very smooth giving a lower degree of friction against a co-operating shaft journal which in turn gives improved compatibility between bearing surface and shaft journal resulting in lower wear rates.
The organic constituent of the tin overlay produces an increased hardness in the range from about 20 to 30 Hv. Pure tin with no organic levelling agent, depending upon its condition, has a hardness of about 8–12 Hv. The hardness of the tin overlay can be changed depending upon the content of the organic levelling agent in the plating bath; the lower the content, the lower the corresponding hardness. The reverse is also true in that as the content of levelling agent increases, so also does the hardness. However, it is possible to have too high a content of organic levelling agent such that the hardness is too high and high internal stresses are produced in the deposit which can lead to cracking of the tin deposit. It is intended that the overlay of the bearing of the present invention operates in a similar manner to conventional overlays in that the overlay layer is sufficiently soft to permit particles of dirt circulating in the lubricating oil to become embedded in the overlay so as to prevent such dirt particles from scoring the shaft journal. Whilst the tin overlay of the present invention is harder than pure tin by a factor of X2 to X3 it is still sufficiently soft to provide the required characteristic of dirt embeddability thus, the preferred hardness range is 20 to 30 Hv.
The bearing of the present invention may preferably have an interlayer between the surface of the first bearing material and the tin overlay to act as a diffusion barrier therebetween. The metal layer may be of a thickness lying in the range from about 0.1 to about 3 μm with a thickness of 1 to 2 μm being preferred, however, the actual thickness is of comparatively little importance in terms of bearing performance. The metal may be selected from the non-exhaustive group including nickel, cobalt, copper, silver, iron and alloys of these metals, for example. It has been found that under engine operating conditions the tin overlay reacts with the nickel interlayer over time to form the stable equilibrium intermetallic compound, Ni 3 Sn 4 , due to the presence of effectively an excess of tin. As noted above, prior art lead-10tin overlays tended to form the unstable, non-equilibrium Ni 3 Sn or Ni 3 Sn 2 compounds which are poor bearing materials and have inferior compatibility with a shaft journal and have been blamed in the past for causing seizure when the overlay has worn through to the interlayer. Ni 3 Sn 4 on the other hand is a very good bearing material and thus, the overlay of the present invention in addition to having superior resistance to wear and cavitation erosion is also less prone to seizure when the overlay is nearing the end of its life. Thus, this unforeseen effect of generating a good bearing material at the interface is seen as a significant advantage of the bearing of the present invention.
As with known overlay layers, the thickness of the overlay of the bearing of the present invention may lie in the range from about 10 to 30 μm with 13 to 18 μm being preferred.
The deposition conditions for tin overlays according to the present invention may be varied to produce a range of microstructures. For example, analysis of the tin overlay layer by SEM has revealed no discernible grain size; even at magnifications of X5000 and X10000 no grains can be resolved. However, coatings having grain sizes of up to 3 μm may be produced. It is preferred, however, that a smaller grain size is produced as these provide improved bearing properties.
According to a second aspect of the present invention, there is provided a method for the deposition of an overlay layer onto the surface of a plain bearing, the bearing comprising a strong backing material having a layer of a first bearing material thereon, said overlay being deposited upon the surface of said first bearing material, the method comprising the steps of: providing a bearing having a surface on which to deposit said overlay; immersing said bearing in a plating solution having a supply of tin ions and an organic levelling agent in said solution; making said bearing cathodic with respect to an anode in said solution; and depositing an overlay of tin, apart from unavoidable impurities, said tin overlay also having said organic levelling agent included in a matrix thereof.
It is preferred to deposit the tin overlay of the bearing of the present invention by using a so-called “slot jig” wherein the bearing is held with its joint faces against a back face of the slot jig with the bore of the bearing facing the slot, the bearing axis and slot being generally parallel to each other. The plating solution, in which the bearing and slot jig are immersed, is also then sparged through the slot towards the bearing bore.
In this way it has been found that relatively high current densities of 2 to 3 A/dm 2 may be employed compared with less than 1 A/dm 2 where the bearing is merely immersed in the plating solution without sparging thereof. Furthermore, the quality of the deposited tin layer is greatly improved compared with that produced without sparging. The use of high current density permitted by the slot jig and sparging technique also reduces plating time from more than 40 minutes to less than 20 minutes.
A typical plating solution producing a tin/organic material overlay on a bearing according to the present invention may have a composition as follows:
Sn ++
32–38
g/l
SnSO 4
58–68
g/l
H 2 SO 4
185–210
g/l
Cu
<50
mg/l
Chloride
<20
ppm
Levelling agent additions of nonylphenolpolyglycolether (10–25%) in a methanol carrier (2.5–10%) in the range from 18 to 70 ml/l to the solution specified above have been tested. At the lower end of the range it was found that the degree of levelling and hardness increase was insufficient whilst at the upper end of the range it was found that there was too much inherent stress in the tin deposit and cracking occurred. It was found that concentration in the range from 25 to 55 ml/l gave useful increases in overlay performance with little or acceptable deterioration of the fundamental requirements of an overlay alloy in terms of conformability and dirt embeddability. The content of pyrocatecol was 2.5–10% and amphoteres tensid 2.5% maximum.
BRIEF DESCRIPTION OF THE DRAWINGS
It has been found that the leveller content has a substantially directly proportional effect on hardness of the tin deposit. However, a limit of leveller content is reached after which the hardness of the tin deposit remains constant and then actually begins to fall after further increasing the leveller content. Similarly, the leveller content also has a directly proportional effect on surface roughness once the effect of the initial substrate roughness and greatly increased surface roughness of the initial leveller-free tin deposit have been overcome.
In order that the present invention may be more fully understood, examples will now be described by way of illustration only with reference to the accompanying figures, of which:
FIG. 1 shows a cross section through a part of a schematic bearing according to the present invention showing the constituent layers;
FIG. 2 shows a top view of a schematic arrangement of a plating jig having a bearing being plated with a tin/organic material according to the method of the present invention;
FIG. 3 shows a histogram of mean thickness loss of overlay vs main journal number in an engine test comparing bearings according to the present invention and bearings plated with known Pb/In overlays;
FIG. 4 shows a histogram of weight loss vs main journal number of overlays of bearings according to the present invention and known Pb/In plated bearings in a 3000 hour engine test;
FIG. 5 shows a histogram of volume loss of overlays of bearings according to the present invention and known Pb/In and Pb/Sn/Cu overlays in a hot oil corrosion test;
FIG. 6 shows a histogram of fatigue strength of bearings according to the present invention having a tin/organic material overlay and known Pb/In and Pb/Sn/Cu overlays;
FIG. 7 shows a histogram of volume loss of overlays of bearings according to the present invention, Pb/Sn/Cu and Pb/In overlays;
FIG. 8 shows a graph of leveller content vs hardness; and
FIG. 9 which shows a graph of leveller content vs surface roughness of the deposit on a substrate.
DETAILED DESCRIPTION
Referring now to FIG. 1 which shows a cross section of a small portion of a generalised bearing 10 according to the present invention. The bearing comprises: a strong backing material 12 (only a part of the thickness of which is shown); a layer of a first bearing material 14 bonded to the backing 12 ; an interlayer 16 ; and, an overlay layer 18 of tin which includes an organic levelling agent combined in the matrix thereof. The backing layer 12 may be steel, for example, but may be any other suitable material such as bronze for example if corrosion conditions in the application dictated such. The first bearing material layer 14 may be any that is suitable but will generally be chosen from copper-based alloys or aluminium-based alloys. The interlayer 16 is present to form a diffusion barrier to stop rapid diffusion of the tin from the overlay 18 into the bearing alloy layer 14 in the case of copper-based alloys 14 and to improve the adhesion of the overlay to the bearing alloy in the case of aluminium-based alloys 14 . The interlayer will generally be deposited by electro-deposition where the overlay is so deposited and may comprise a layer of nickel or other suitable material as described hereinabove. In use, the bearing 10 will be subject to temperatures up to about 160° C. At temperatures of 90° C. and above, the tin from the overlay will react with the interlayer material to form the stable intermetallic compound Ni 3 Sn 4 in the case of a nickel interlayer. The rate of formation increases as the temperature rises. The Ni 3 Sn 4 layer grows at the expense of the overlay, however, the Ni 3 Sn 4 layer is a good bearing material per se with good compatibility with the co-operating shaft journal (not shown) and thus, does not present a possible seizure threat. The thickness of the interlayer 16 generally lies in the range from 1 to 3 μm and the thickness of the overlay 18 generally in the range from 13 to 18 μm.
FIG. 2 shows a top plan view of a schematic arrangement 20 of electro-plating apparatus for depositing an overlay 18 on a bearing 10 . The apparatus comprises a jig 22 having two plates 24 , 26 spaced either side of a slot 28 . The bearing 10 is held against the plates 24 , 26 on its joint faces 30 . The jig 22 is immersed in a bath (not shown) of plating solution 32 as is a tin anode 34 of generally cylindrical form. The bearing 10 is made cathodic by a suitable electrical connection (not shown). A sparging tube 36 having holes 38 is situated vertically in the bath in a fixed relationship to the slot 28 . Plating solution is pumped through the tube 36 so as to emerge in jet form, as indicated by the arrows 40 , which are directed towards the bore of the bearing 10 through the slot 28 . Although not apparent from FIG. 2 , the jig 22 is elongate as are the anode 34 and sparging tube 36 and there is generally a stack of a plurality of bearings 10 being plated simultaneously.
In the tests results which follow, the overlay was deposited upon the relevant substrate alloy bearing alloy 14 and interlayer 16 from a plating bath having the following composition:
Sn ++
32–38
g/l
SnSO 4
58–68
g/l
H 2 SO 4
185–210
g/l
Cu
<50
mg/l
Chloride
<20
ppm
Levelling agent additions of nonylphenolpolyglycolether (10–25%) in a methanol carrier (2.5–10%) in the range from 32 to 35 ml/l were added to the above aqueous solution.
The interlayer 16 material was in all cases nickel.
FIG. 3 indicates the results of a 3000 hour test on a Volvo (trade name) diesel truck engine. Main bearings 1 to 4 inclusive were fitted with bearings according to the present invention as described above whilst main bearings 5 to 7 inclusive were fitted with bearings of the same material and construction but having a conventional overlay of Pb-7In. As may be seen from the histogram of FIG. 3 , the mean overlay thickness loss for bearings of the present invention was less than 10% that of the conventional overlay.
FIG. 4 shows the results of the 3000 hour Volvo engine test of FIG. 3 in terms of weight loss. Weight loss of the bearings according to the present invention was significantly less than 100 mg each for the four main bearings on journals 1 to 4 whereas the weight loss of the bearings on journals 5 to 7 was around 1000 mg each.
FIG. 5 is a histogram showing weight loss of overlays in hot oil (white medicinal oil which is chosen for its particularly corrosive nature) after 1000 hours at 120° C., the loss being measured in mm 3 . The bearing material on which the overlays were deposited has a composition CuSn10 which was cast onto steel. The overlays were tin as in the present invention, Pb-7In and Pb-10Sn-2Cu. As may be seen from FIG. 5 , the volume loss of overlays on bearings according to the present invention was about 60% that of Pb-10Sn-2Cu and much less than 10% that of the Pb-7In overlay.
FIG. 6 is a histogram showing the fatigue strength of bearings having the overlays specified The bearings according to the present invention were tested in two forms: one having a thickness of 18 μm at the upper end of the preferred thickness range; and, the second having a thickness of 14 μm at the lower end of the preferred thickness range. The overlay thicknesses of the prior art Pb-10Sn-2Cu and Pb-7In overlays was 15–16 μm. As may be seen from FIG. 6 the fatigue strength of the bearings according to the present invention was significantly greater than the prior art bearings.
Further tests were carried out where the tin overlay having a thickness in the range from 13 to 18 μm was deposited on bearing materials 14 of Cu-30Pb-1.5Sn and Cu-10Sn gave fatigue strengths of 90 to 103 MPa.
FIG. 7 is a histogram showing wear test results showing volume loss of overlay on bearings according to the present invention compared with conventional overlays as described hereinabove. The test conditions were: temperature 120°; load 8 kg; speed 500 rev/min; duration 10 mins; and a constant flow of 10 W oil at 600 ml/min. As may be seen from FIG. 7 the volume loss of overlays according to the present invention is less than 50% of Pb-10Sn-2Cu and less than 40% that of Pb-7In.
Tests were also carried out on the cavitation resistance of overlays on bearings according to the present invention. In these tests, the weight loss of the tin overlay of the inventive bearing was 9 mg whereas the weight loss of a Pb-7In overlay under identical conditions was 37 mg.
FIG. 8 shows the effect of leveller content in the plating bath on the hardness of the tin deposit. It may be seen that the hardness increases linearly with increasing content of leveller which was the same as that in the previously described example.
FIG. 9 shows the effect of leveller content on surface roughness of the tin deposit. At low leveller contents below about 2 ml/l of leveller, the high roughness is a consequence of the substrate surface roughness which was an Ra of o.44 and the roughening effect of the initial, substantially leveller-free tin deposit. Once the effect of the leveller was such that the surface roughness matched that of the substrate then increasing quantities of leveller were directly proportional to the surface roughness.
Thus, relatively low contents of leveller have a strong effect in hardening and smoothing out surface roughness of the tin overlays of the present invention.
Thus, it may be seen that the performance of overlays on bearings according to the present invention is greatly superior to the best conventional overlays deposited by electro-deposition. Where the overlay is deposited upon a lead-free bearing material 14 , the bearing of the present invention provides a completely lead-free bearing which complies with future legislation relating to the elimination of lead from vehicles. | A plain bearing and method for making the plain bearing are described, the plain bearing having an overlay alloy layer at a sliding surface of the plain bearing, the plain bearing comprising a layer of a strong backing material, a layer of a first bearing alloy bonded to the strong backing material and a layer of a second bearing material comprising said overlay material bonded to said first bearing alloy layer wherein said second bearing material comprises tin having included in the matrix thereof an organic levelling agent. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/399,435, filed Jul. 31, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention is in the field of medicinal chemistry. In particular, the invention relates to novel aryl substituted hydantoins, and the discovery that these compounds are blockers of sodium (Na+) channels.
[0004] 2. Related Art
[0005] Several classes of therapeutically useful drugs, including local anesthetics such as lidocaine and bupivacaine, antiarrhythmics such as propafenone and amioclarone, and anticonvulsants such as lamotrigine, phenytoin and carbamazepine, have been shown to share a common mechanism of action by blocking or modulating Na + channel activity (Catterall, W. A., Trends Pharmacol. Sci. 8:57-65 (1987)). Each of these agents is believed to act by interfering with the rapid influx of Na + ions.
[0006] Recently, other Na + channel blockers such as BW619C89 and lifarizine have been shown to be neuroprotective in animal models of global and focal ischemia and are presently in clinical trials (Graham et al., J. Pharmacol. Exp. Ther. 269:854-859 (1994); Brown et al., British J. Pharmacol. 115:1425-1432 (1995)).
[0007] The neuroprotective activity of Na + channel blockers is due to their effectiveness in decreasing extracellular glutamate concentration during ischemia by inhibiting the release of this excitotoxic amino acid neurotransmitter. Studies have shown that unlike glutamate receptor antagonists, Na + channel blockers prevent hypoxic damage to mammalian white matter (Stys et al., J. Neurosci. 12:430-439 (1992)). Thus, they may offer advantages for treating certain types of strokes or neuronal trauma where damage to white matter tracts is prominent.
[0008] Another example of clinical use of a Na + channel blocker is riluzole. This drug has been shown to prolong survival in a subset of patients with ALS (Bensimm et al., New Engl. J. Med. 330:585-591 (1994)) and has subsequently been approved by the FDA for the treatment of ALS. In addition to the above-mentioned clinical uses, carbamazepine, lidocaine and phenytoin are occasionally used to treat neuropathic pain, such as from trigeminal neurologia, diabetic neuropathy and other forms of nerve damage (Taylor and Meldrum, Trends Pharmacol. Sci. 16:309-316 (1995)), and carbamazepine and lamotrigine have been used for the treatment of manic depression (Denicott et al., J. Clin. Psychiatry 55:70-76 (1994)). Furthermore, based on a number of similarities between chronic pain and tinnitus, (Moller, A. R. Am. J. Otol. 18:577-585 (1997); Tonndorf, J. Hear. Res. 28:271-275 (1987)) it has been proposed that tinnitus should be viewed as a form of chronic pain sensation (Simpson, J. J. and Davies, E. W. Tips. 20:12-18 (1999)). Indeed, lignocaine and carbamazepine have been shown to be efficacious in treating tinnitus (Majumdar, B. et al. Clin. Otolaryngol. 8:175-180 (1983); Donaldson, I. Laryngol. Otol. 95:947-951 (1981)).
[0009] It has been established that there are at least five to six sites on the voltage-sensitive Na + channels which bind neurotoxins specifically (Catterall, W. A., Science 242:50-61 (1988)). Studies have further revealed that therapeutic antiarrhythmics, anticonvulsants and local anesthetics whose actions are mediated by Na + channels, exert their action by interacting with the intracellular side of the Na + channel and allosterically inhibiting interaction with neurotoxin receptor site 2 (Catterall, W. A., Ann. Rev. Pharmacol. Toxicol. 10:15-43 (1980)).
[0010] A need exists in the art for novel compounds that are potent blockers of sodium channels, and are therefore useful for treating a variety of central nervous system conditions, including pain.
SUMMARY OF THE INVENTION
[0011] One aspect of the present invention is directed to the novel aryl substituted hydantoins of Formula I.
[0012] The present invention is also related to the discovery that aryl substituted hydantoins represented by Formula I act as blockers of sodium (Na + ) channels.
[0013] Another aspect of the present invention is directed to the use of novel compounds of Formula I as blockers of sodium channels.
[0014] The invention is also related with treating a disorder responsive to the blockade of sodium channels in a mammal suffering from excess activity of said channels by administering an effective amount of a compound of Formula I as described herein.
[0015] A further aspect of the present invention is to provide a method for treating, preventing or ameliorating neuronal loss following global and focal ischemia; treating, preventing or ameliorating pain including acute and chronic pain, and neuropathic pain; treating, preventing or ameliorating convulsion and neurodegenerative conditions; treating, preventing or ameliorating manic depression; using as local anesthetics and anti-arrhythmics, and treating tinnitus by administering a compound of Formula I to a mammal in need of such treatment or use.
[0016] Also, an aspect of the present invention is to provide a pharmaceutical composition useful for treating disorders responsive to the blockade of sodium ion channels, containing an effective amount of a compound of Formula I in a mixture with one or more pharmaceutically acceptable carriers or diluents.
[0017] Additional embodiments and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or can be learned by practice of the invention. The embodiments and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Novel compounds of the present invention are aryl substituted hydantoins represented by Formula I:
[0020] or a pharmaceutically acceptable salt, or solvate thereof, wherein:
[0021] n is 0 to 3;
[0022] A and A′ are independently oxygen or sulfur;
[0023] R is hydrogen, linear or branched C 1-6 alkyl, optionally substituted benzyl, thio(C 1-6 )alkyl, C 1-6 alkylthio(C 1-6 )alkyl, hydroxy(C 1-6 )alkyl, amino(C 1-6 )alkyl, guanidinyl(C 1-6 )alkyl, carboxy(C 1-6 )alkyl or aminocarboxy(C 1-6 )alkyl;
[0024] R 1 is selected from the group consisting of:
[0025] (i) optionally substituted phenoxyphenyl;
[0026] (ii) optionally substituted benzyloxyphenyl;
[0027] (iii) optionally substituted phenylthiophenyl;
[0028] (iv) optionally substituted benzylthiophenyl;
[0029] (v) optionally substituted phenylaminophenyl;
[0030] (vi) optionally substituted benzylaminophenyl; and
[0031] wherein each occurrence of R 6 and each occurrence of R 7 are independently C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, C 1-6 hydroxyalkyl or C 1-6 alkoxy(C 1-6 )alkyl; and
[0032] p and q are independently integers from zero to 4;
[0033] wherein R 8 is hydrogen, halogen, hydroxy, C 1-6 alkyl, C 1-6 alkoxy, cyano, amino, or nitro;
[0034] wherein R 9 is hydrogen or C 1-6 alkyl; and
[0035] (x) optionally substituted naphthyl; and
[0036] R 2 is selected from the group consisting of:
[0037] where
[0038] Y is an optionally substituted C 2-6 alkylene, and
[0039] R 3 and R 4 are the same or different and are hydrogen, alkyl, or aryl, or R 3 and R 4 together form an alkylene chain having 3 to 5 carbon atoms, optionally substituted with an alkyl or aryl moiety, or said alkylene chain is optionally interrupted by an oxygen atom or —NR 5 , where R 5 is hydrogen or C 1-6 alkyl;
[0040] (ii) pyridylalkyl; and
[0041] (iii) piperidin-4-ylalkyl, optionally substituted by alkyl, aryl or aralkyl.
[0042] Preferred compounds of Formula I are those wherein R 1 is phenoxyphenyl or benzyloxyphenyl, wherein the phenyl group of the phenoxy or benzyloxy moiety is optionally substituted with alkyl, alkoxy, halogen or haloalkyl. Preferred substituents include one to three, preferably one or two, substituents independently selected from the group consisting of C 1-4 alkyl, C 1-4 alkoxy, halogen, or C 1-4 haloalkyl. Suitable values of R 1 in this embodiment of the invention include (3-phenoxy)phenyl, (4-phenoxy)phenyl, (3-benzyloxy)phenyl, (4-benzyloxy)phenyl, any of which is optionally substituted by one, two or three groups independently selected from the group consisting of fluoro, chloro, bromo, methyl, ethyl, propyl, isopropyl, methoxy, ethoxy, fluoromethyl, and trifluormethyl.
[0043] Preferred compounds of Formula I are those wherein R is optionally substituted phenoxyphenyl or optionally substituted benzyloxyphenyl; R 3 and R 4 together with the nitrogen to which they are attached form a piperidinyl, morpholinyl or pyrrolidinyl group; and Y is an optionally substituted C 2-6 alkylene chain.
[0044] Preferred compounds of Formula I are also those wherein R 1 is optionally substituted phenoxyphenyl or optionally substituted benzyloxyphenyl; and R 3 and R 4 are independently hydrogen, alkyl or aryl; and Y is an optionally substituted C 14 alkylene chain.
[0045] Preferred compounds are those of Formula I wherein R 1 is
[0046] where R 6 and R 7 are independently alkyl, alkoxy, halo, or haloalkyl, and where either or both of p and q are independently greater than 1, R 6 can independently be the same or different, and R 7 can independently be the same or different, and p and q are independently 0-4, preferably 0, 1 or 2. When R 6 and/or R 7 is present, these groups substitute for hydrogen atoms at any available position on the phenyl to which they are attached. Preferred substitution positions are para and meta. Preferably, R 6 and R 7 are independently of C 1-4 alkyl, C 1-4 alkoxy, halogen, or C 1-4 haloalkyl. Useful values of R 6 and R 7 include fluoro, chloro, bromo, methyl, ethyl, propyl, isopropyl, methoxy, ethoxy, fluoromethyl, and trifluormethyl.
[0047] Additionally, preferred compounds are those of Formula I wherein R 1 is
[0048] where R 8 is as defined above, and is preferably hydrogen or C 1-4 alkyl, such as methyl, ethyl, propyl and isopropyl. R 8 replaces a hydrogen atom at any available position on the phenyl ring.
[0049] Additionally, preferred compounds are those of Formula I wherein R 1 is
[0050] where R 9 is as defined above, and is preferably hydrogen or C 1-4 alkyl, such as methyl, ethyl, propyl and isopropyl.
[0051] Preferred compounds also are those of Formula I wherein R 1 is naphthyl.
[0052] Further, additionally preferred compounds of Formula I are those wherein the —(CH 2 ) n — is attached to the 3- or 4-position of the phenyl component of the phenoxyphenyl or the benzyloxyphenyl defined by R 1 .
[0053] Still, additionally preferred compounds of Formula I are those wherein n is 1; Y is C 2-6 alkylene; and R 3 and R 4 together with the nitrogen to which they are attached, form a piperidinyl, morpholinyl or pyrrolidinyl group.
[0054] Other preferred compounds of Formula I are those wherein n is 1; Y is C 2-6 alkylene; and R 3 and R 4 are the same or different and are selected from hydrogen, alkyl, or aryl.
[0055] Additionally preferred compounds of Formula I are those wherein R 2 is pyridylalkyl.
[0056] Preferred compounds of Formula I are also those wherein R 2 is piperidin-4-ylalkyl, optionally substituted by alkyl, aryl or aralkyl.
[0057] The term “alkyl” means a linear or branched C 1-10 carbon chain, preferably a C 1-6 carbon chain. Suitable alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, 3-pentyl, hexyl and octyl groups.
[0058] For purposes of the present invention, the term “alkylene” has the meaning —(CH 2 )—, where m is an integer of from 1-6, preferably 2-4. Suitable alkylene chains include but are not limited to methylene, ethylene, propylene, butylene, pentylene and hexylene. The alkylene chain can also be optionally substituted.
[0059] The term “optionally substituted,” means optional replacement of one or more carbon-attached hydrogens with halogen, halo(C 1-6 )alkyl, aryl, heterocycle, cycloalkyl, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, aryl(C 1-6 )alkyl, aryl(C 2-6 ) alkenyl, aryl(C 2-6 )alkynyl, cycloalkyl(C 1-6 )alkyl, heterocyclo(C 1-6 alkyl), hydroxy(C 1-6 )alkyl, amino(C 1-6 )alkyl, carboxy(C 1-6 )alkyl, alkyloxy(C 1-6 )alkyl, nitro, amino, ureido, cyano, acylamino, hydroxy, thiol, acyloxy, azido, alkyloxy, carboxy, aminocarbonyl, and C 1-6 alkylthiol; and where one or more carbon-attached hydrogens are part of a ring system “optionally substituted,” in addition to those groups listed above, also includes alkyl.
[0060] The term “optionally substituted alkylene chain,” means optional replacement of one or more carbon-attached hydrogens with halogen, halo(C 1-6 )alkyl, aryl, heterocycle, cycloalkyl, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, aryl(C 1-6 )alkyl, aryl(C 2-6 )alkenyl, aryl(C 2-6 )alkynyl, cycloalkyl(C 1-6 )alkyl, heterocyclo(C 1-6 )alkyl, hydroxy(C 1-6 )alkyl, amino(C 1-6 )alkyl, carboxy(C 1-6 )alkyl, alkyloxy(C 1-6 ) alkyl, nitro, amino, ureido, cyano, acylamino, hydroxy, thiol, acyloxy, azido, alkyloxy, carboxy, aminocarbonyl, and C 1-6 alkylthiol. Preferably, “optionally substituted alkylene chain” will mean replacement with one or more alkyl groups or halogen atoms, preferably alkyl groups.
[0061] The term “aryl” means a C 6-14 mono- or polycyclic aromatic ring system. Suitable carbocyclic aryl groups can be selected from, but are not limited to, phenyl, naphthyl, phenanthryl, anthracyl, indenyl, azulenyl, biphenyl, biphenylenyl and fluorenyl groups. Particularly useful carbocyclic aryl groups are phenyl and naphthyl.
[0062] The term “aralkyl” means an alkyl group substituted by a C 6-14 mono- or polycyclic aromatic ring system. Suitable carbocyclic aryl groups can be selected from, but are not limited to, phenyl, naphthyl, phenanthryl, anthracyl, indenyl, azulenyl, biphenyl, biphenylenyl and fluorenyl groups. Particularly preferred carbocyclic aryl groups are phenyl and naphthyl. Preferred alkyl groups are linear or branched C 1-10 carbon chain, preferably a C 1-6 carbon chain. Suitable alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, 3-pentyl, hexyl and octyl.
[0063] The term “heterocycle” means a 3- to 7-membered monocyclic or a 7-to 14-membered polycyclic non-aromatic ring system, independently containing one or more nitrogen, oxygen or sulfur atoms. Saturated or partially saturated heterocycle groups that are suitable for use in the present invention include, but are not limited to, piperidinyl, tetrahydrofuranyl, pyranyl, piperizinyl, pyrrolidinyl, imidazolindinyl, imidazolinyl, indolinyl, isoindolinyl, quinuclidinyl, morpholinyl, isochromanyl, chromanyl, pyrazolidinyl and pyrazolinyl.
[0064] The term “cycloalkyl” means an alkyl group substituted by a 3- to 9-membered monocyclic or a 7- to 14-membered polycyclic non-aromatic carbon ring system. Saturated or partially saturated cycloalkyl groups that are suitable for use in the present invention include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclononenyl adamantyl, norbomyl, and norbomenyl. Preferred alkyl groups are linear or branched C 1-10 carbon chain, preferably a C 1-6 carbon chain. Suitable alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, 3-pentyl, hexyl and octyl.
[0065] Exemplary compounds that can be employed in this method of invention include, without limitation:
[0066] 3-(2-piperidinylethyl)-1-(4-(4-flurophenoxy)benzyl) hydantoin;
[0067] 3-(2-piperidinylethyl)-1-(4-(benzyloxy)benzyl) hydantoin;
[0068] 3-(2-piperidinylethyl)-1-(3-(4-trifluromethylphenoxy)benzyl) hydantoin;
[0069] 3-(2-piperidinylethyl)-1-(3-(3,4-dichlorophenoxy)benzyl) hydantoin;
[0070] 3-(2-piperidinylethyl)-1-(3-(phenoxy)benzyl) hydantoin; and
[0071] 3-(2-piperidinylethyl)-1-(3-(benzyloxy)benzyl) hydantoin;
[0072] as well as pharmaceutically acceptable salts thereof.
[0073] Particularly preferred compounds of the invention are selected from:
[0074] 3-(2-piperidinylethyl)-1-(3-(4-trifluromethylphenoxy)benzyl) hydantoin;
[0075] 3-(2-piperidinylethyl)-1-(3-(3,4-dichlorophenoxy)benzyl) hydantoin;
[0076] 3-(2-piperidinylethyl)-1-(3-(benzyloxy)benzyl) hydantoin; and
[0077] pharmaceutically acceptable salts thereof.
[0078] The invention disclosed herein is meant to encompass all pharmaceutically acceptable salts thereof of the disclosed compounds. The pharmaceutically acceptable salts include, but are not limited to, metal salts such as sodium salt, potassium salt, cesium salt and the like; alkaline earth metals such as calcium salt, magnesium salt and the like; organic amine salts such as triethylamine salt, pyridine salt, picoline salt, ethanolamine salt, triethanolamine salt, dicyclohexylamine salt, N,N′-dibenzylethylenediamine salt and the like; inorganic acid salts such as hydrochloride, hydrobromide, sulfate, phosphate and the like; organic acid salts such as formate, acetate, trifluoroacetate, maleate, tartrate and the like; sulfonates such as methanesulfonate, benzenesulfonate, p-toluenesulfonate, and the like; amino acid salts such as arginate, asparginate, glutamate and the like.
[0079] The invention disclosed herein is also meant to encompass prodrugs of the disclosed compounds. Prodrugs are considered to be any covalently bonded carrier which releases the active parent drug in vivo.
[0080] The invention disclosed herein is also meant to encompass the in vivo metabolic products of the disclosed compounds. Such products can result for example from the oxidation, reduction, hydrolysis, amidation, esterification and the like of the administered compound, primarily due to enzymatic processes. Accordingly, the invention includes compounds produced by a process comprising contacting a compound of this invention with a mammal for a period of time sufficient to yield a metabolic product thereof. Such products typically are identified by preparing a radiolabelled compound of the invention, administering it parenterally in a detectable dose to an animal such as rat, mouse, guinea pig, monkey, or to man, allowing sufficient time for metabolism to occur and isolating its conversion products from the urine, blood or other biological samples.
[0081] The invention disclosed herein is also meant to encompass the disclosed compounds being isotopically-labelled by having one or more atoms replaced by an atom having a different atomic mass or mass number. Examples of isotopes that can be incorporated into the disclosed compounds include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine and chlorine, such as 2 H, 3 H, 13 C, 14 C, 15 N, 18 O 17 O, 31 P, 32 P, 35S, 18 F, and 36 Cl, respectively.
[0082] Some of the compounds disclosed herein can contain one or more asymmetric centers and can thus give rise to enantiomers, diastereomers, and other stereoisomeric forms. The present invention is also meant to encompass all such possible forms as well as their racemic and resolved forms and mixtures thereof. When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, and unless specified otherwise, it is intended to include both E and Z geometric isomers. All tautomers are encompassed by the present invention as well.
[0083] As used herein, the term “stereoisomers” is a general term for all isomers of individual molecules that differ only in the orientation of their atoms in space. It includes enantiomers and isomers of compounds with more than one chiral center that are not mirror images of one another (diastereomers).
[0084] The term “chiral center” refers to a carbon atom to which four different groups are attached.
[0085] The term “enantiomer” or “enantiomeric” refers to a molecule that is nonsuperimposeable on its mirror image and hence optically active wherein the enantiomer rotates the plane of polarized light in one direction and its mirror image rotates the plane of polarized light in the opposite direction.
[0086] The term “racemic” refers to a mixture of equal parts of enantiomers and which is optically inactive.
[0087] The term “resolution” refers to the separation or concentration or depletion of one of the two enantiomeric forms of a molecule. The phrase “enantiomeric excess” refers to a mixture wherein one enantiomer is present is a greater concentration than its mirror image molecule.
[0088] The hydantoins of Formula I can be prepared using methods known to those skilled in the art. Specifically, the hydantoins of the present invention are generally obtained from a method comprising:
[0089] (a) reacting an amine protected amino acid with a resin supported hydroxy group to produce a resin supported, amine protected, amino acid;
[0090] (b) deprotecting said resin supported amine protected amino acid, to produce a resin supported amino acid having an N-terminus primary amine;
[0091] (c) reacting said resin supported amino acid obtained in step (b), with an aldehyde to produce a resin supported enamine;
[0092] (d) reducing said resin supported enamine obtained in from step (c), to produce a resin supported amino acid, having an N-terminus secondary amine;
[0093] (e) reacting said resin supported amino acid obtained from step (d), with triphosgene, to produce a resin supported amino acid having an N-terminus tertiary amine, wherein said tertiary amine comprises a carbonyl chloride moiety;
[0094] (f) reacting said resin supported amino acid obtained from step (e), with a primary amine; and
[0095] (g) releasing a product obtained from step (f) from its support, to obtain the compound of Formula I.
[0096] For this method, the aldehyde in (c) has the formula:
[0097] wherein n is 1-3 and R 1 is as defined above.
[0098] Additionally, for this method, the primary amine in step (f) is selected from the group consisting of:
[0099] wherein
[0100] Y is a C 2-6 alkylene; and
[0101] R 3 and R 4 are the same or different and are selected from hydrogen, alkyl, or aryl, or R 3 and R 4 together form an alkylene chain having 4 to 5 carbon atoms, optionally substituted with an alkyl or aryl moiety, or said alkylene chain is optionally interrupted by an oxygen atom or —NR 5 , where R 5 is hydrogen or alkyl;
[0102] (i) pyridylalkyl amine; and
[0103] (ii) an optionally substituted piperidin-4-ylalkyl amine, wherein optional substituents are selected from the group consisting of alkyl, aryl or aralkyl.
[0104] The general method of making hydantoins of the present invention is shown in the following reaction scheme.
[0105] Other commercially available protected amino acids can be substituted for N-Fmoc-Gly-OH (i.e., FMOC-NH-Gly-COOH) in step 1 to form compounds of Formula I where R is other than hydrogen.
[0106] Compounds of Formula I, wherein n is 0, can also be prepared according to a modification of Scheme I above, comprising:
[0107] (a) reacting a resin supported hydroxymethyl group with halogenated acetic acid to produce a supported halogenated acetate;
[0108] (b) reacting said supported halogenated acetate from step (a) with an R 1 -containing primary amine, to form a supported R 1 -substituted glycine;
[0109] (c) reacting said supported R 1 -substituted glycine obtained from step (b), with triphosgene, to produce a resin supported amino acid having an N-terminus tertiary amine, wherein said tertiary amine comprises a carbonyl chloride moiety;
[0110] (d) reacting said resin supported amino acid obtained from step (c), with a primary amine; and
[0111] (e) releasing a product obtained from step (d) from its support, to obtain the compound of Formula I wherein n is 0.
[0112] The general method of making hydantoins of Formula I, where n is 0, is shown in reaction Scheme 2.
[0113] Those of ordinary skill in the art would be readily aware of corresponding solution phase methods of making the compound of Formula I.
[0114] The invention is also directed to a method for treating disorders responsive to the blockade of sodium channels in mammals suffering therefrom. The hydantoin compounds of the invention can be used to treat humans or companion animals, such as dogs and cats. Particular preferred embodiments of the hydantoins of the invention for use in treating such disorders are represented as previously defined for Formula I.
[0115] The compounds of the present invention are assessed by electrophysiological assays in dissociated hippocampal neurons for sodium channel blocker activity. These compounds also can be assayed for binding to the neuronal voltage-dependent sodium channel using rat forebrain membranes and [ 3 H]BTX-B.
[0116] Sodium channels are large transmembrane proteins that are expressed in various tissues. They are voltage sensitive channels and are responsible for the rapid increase of Na + permeability in response to depolarization associated with the action potential in many excitable cells including muscle, nerve and cardiac cells.
[0117] One aspect of the present invention is the discovery of the mechanism of action of the compounds herein described as specific Na + channel blockers. Based upon the discovery of this mechanism, these compounds are contemplated to be useful in treating or preventing neuronal loss due to focal or global ischemia, and in treating or preventing neurodegenerative disorders including ALS, anxiety, and epilepsy. They are also expected to be effective in treating, preventing or ameliorating neuropathic pain, surgical pain, chronic pain and tinnitus. The compounds are also expected to be useful as antiarrhythmics, anesthetics and antimanic depressants.
[0118] The present invention is directed to compounds of Formula I that are blockers of voltage-sensitive sodium channels. According to the present invention, those compounds having preferred sodium channel blocking properties exhibit an IC 50 of about 100 μM or less in the electrophysiological assay described herein. Preferably, the compounds of the present invention exhibit an IC 50 of 10 μM or less. Most preferably, the compounds of the present invention exhibit an IC 50 of about 1.0 μM or less. Compounds of the present invention can be tested for their Na+channel blocking activity by the following binding and electrophysiological assays.
[0119] In Vitro Binding Assay:
[0120] The ability of compounds of the present invention to modulate either site 1 or site 2 of the Na+channel was determined following the procedures fully described in Yasushi, J. Biol. Chem. 261:6149-6152 (1986) and Creveling, Mol. Pharmacol. 23:350-358 (1983), respectively. Rat forebrain membranes are used as sources of Na + channel proteins. The binding assays are conducted in 130 μM choline chloride at 37° C. for 60-minute incubation with [ 3 H] saxitoxin and [ 3 H] batrachotoxin as radioligands for site 1 and site 2, respectively.
[0121] In Vivo Pharmacology:
[0122] The compounds of the present invention can be tested for in vivo anticonvulsant activity after i.v., p.o. or i.p. injection using a number of anticonvulsant tests in mice, including the maximum electroshock seizure test (MES). Maximum electroshock seizures are induced in male NSA mice weighing between 15-20 g and male Sprague-Dawley rats weighing between 200-225 g by application of current (50 mA, 60 pulses/sec, 0.8 msec pulse width, 1 sec duration, D.C., mice; 99 mA, 125 pulses/sec, 0.8 msec pulse width, 2 sec duration, D.C., rats) using a Ugo Basile ECT device (Model 7801). Mice are restrained by gripping the loose skin on their dorsal surface and saline-coated corneal electrodes were held lightly against the two corneae. Rats are allowed free movement on the bench top and ear-clip electrodes are used. Current is applied and animals are observed for a period of up to 30 seconds for the occurrence of a tonic hindlimb extensor response. A tonic seizure is defined as a hindlimb extension in excess of 90 degrees from the plane of the body. Results are treated in a quantal manner.
[0123] The compounds can be tested for their antinociceptive activity in the formalin model as described in Hunskaar, S., O. B. Fasmer, and K. Hole, J. Neurosci. Methods 14: 69-76 (1985). Male Swiss Webster NIH mice (20-30 g; Harlan, San Diego, Calif.) are used in all experiments. Food is withdrawn on the day of experiment. Mice are placed in Plexiglass jars for at least 1 hour to accommodate to the environment. Following the accommodation period mice are weighed and given either the compound of interest administered i.p. or p.o., or the appropriate volume of vehicle (10% Tween-80). Fifteen minutes after the i.p. dosing, and 30 minutes after the p.o. dosing mice are injected with formalin (20 μL of 5% formaldehyde solution in saline) into the dorsal surface of the right hind paw. Mice are transferred to the Plexiglass jars and monitored for the amount of time spent licking or biting the injected paw. Periods of licking and biting are recorded in 5 minute intervals for 1 hour after the formalin injection. All experiments are done in a blinded manner during the light cycle. The early phase of the formalin response is measured as licking/biting between 0-5 minutes, and the late phase is measured from 15-50 minutes. Differences between vehicle and drug treated groups are analyzed by one-way analysis of variance (ANOVA). A P value <0.05 is considered significant. Activity in blocking the acute and second phase of formalin-induced paw-licking activity is indicative that compounds are considered to be efficacious for acute and chronic pain.
[0124] The compounds can be tested for their potential for the treatment of chronic pain (antiallodynic and antihyperalgesic activities) in the Chung model of peripheral neuropathy. Male Sprague-Dawley rats weighing between 200-225 g are anesthetized with halothane (1-3% in a mixture of 70% air and 30% oxygen) and their body temperature is controlled during anesthesia through use of a homeothermic blanket. A 2-cm dorsal midline incision is then made at the L5 and L6 level and the para-vertibral muscle groups retracted bilaterally. L5 and L6 spinal nerves are then be exposed, isolated, and tightly ligated with 6-0 silk suture. A sham operation is performed exposing the contralateral L5 and L6 spinal nerves as a negative control.
[0125] Tactile Allodynia: Rats are transferred to an elevated testing cage with a wire mesh floor and allowed to acclimate for five to ten minutes. A series of Semmes-Weinstein monofilaments are applied to the plantar surface of the hindpaw to determine the animal's withdrawal threshold. The first filament used possesses a buckling weight of 9.1 gms (0.96 log value) and is applied up to five times to see if it elicited a withdrawal response. If the animal has a withdrawal response then the next lightest filament in the series is applied up to five times to determine if it can elicit a response. This procedure is repeated with subsequent less filaments until there is no response and the lightest filament that elicits a response is recorded. If the animal does not have a withdrawal response from the initial 9.1 gms filament then subsequent filaments of increased weight are applied until a filament elicits a response and this filament is then recorded. For each animal, three measurements are made at every time point to produce an average withdrawal threshold determination. Tests are performed prior to and at 1, 2, 4 and 24 hours post drug administration. Tactile allodynia and mechanical hyperalgesia tests were conducted concurrently.
[0126] Mechanical Hyperalgesia: Rats are transferred to an elevated testing cage with a wire mesh floor and allowed to acclimate for five to ten minutes. A slightly blunted needle is touched to the plantar surface of the hindpaw causing a dimpling of the skin without penetrating the skin. Administration of the needle to control paws typically produces a quick flinching reaction, too short to be timed with a stopwatch and arbitrarily gives a withdrawal time of 0.5 second. The operated side paw of neuropathic animals exhibits an exaggerated withdrawal response to the blunted needle. A maximum withdrawal time of ten seconds is used as a cutoff time. Withdrawal times for both paws of the animals are measured three times at each time point with a five-minute recovery period between applications. The three measures are used to generate an average withdrawal time for each time point. Tactile allodynia and mechanical hyperalgesia tests are conducted concurrently.
[0127] The compounds can be tested for their neuroprotective activity after focal and global ischemia produced in rats or gerbils according to the procedures described in Buchan et al. (Stroke, Suppl. 148-152 (1993)) and Sheardown et al. (Eur. J. Pharmacol. 236:347-353 (1993)) and Graham et al. (J. Pharmacol. Exp. Therap. 276:1-4 (1996)).
[0128] The compounds can be tested for their neuroprotective activity after traumatic spinal cord injury according to the procedures described in Wrathall et al. (Exp. Neurology 137:119-126 (1996)) and Iwasaki et al. (J. Neuro Sci. 134:21-25 (1995)).
[0129] Electrophysiological Assay:
[0130] An electrophysiological assay was used to measure potencies of compounds of the present invention as antagonists of rBIIa/beta 1 sodium channels expressed in Xenopus oocytes.
[0131] Preparation of cRNA encoding cloned rat brain type IIa (rBIIa) and beta 1 (β1): cDNA clones encoding the rat brain beta 1 subunit are cloned in house using standard methods, and mRNA are prepared by standard methods. MRNA encoding rBIIa is provided by Dr. A. Golden (UC Irvine). The mRNAs are diluted and stored at −80° C. in 1 μL aliquots until injection.
[0132] Preparation of oocytes: Mature female Xenopus laevis are anaesthetized (20-40 min) using 0.15% 3-aminobenzoic acid ethyl ester (MS-222) following established procedures (Woodward, R. M., et al., Mol. Pharmacol. 41:89-103 (1992)).
[0133] Two to six ovarian lobes are surgically removed. Oocytes at developmental stages V-VI are dissected from the ovary, wherein the oocytes are still surrounded by enveloping ovarian tissues. Oocytes are defolliculated on the day of surgery by treatment with collagenase (0.5 mg/mL Sigma Type I, or Boehringer Mannheim Type A, for 0.5-1 hr). Treated oocytes are vortexed to dislodge epithelia, washed repeatedly and stored in Barth's medium containing 88 mM NaCl, 1 mM KCl, 0.41 mM CaCl 2 , 0.33 mM Ca(NO 3 ) 2 , 0.82 mM MgSO 4 , 2.4 mM NaHCO 3 , 5 mM HEPES, pH 7.4 adjusted with 0.1 mg/mL gentamycin sulphate.
[0134] Micro-injection of oocytes: Defolliculated oocytes are micro-injected using a Nanoject injection system (Drummond Scientific Co., Broomall, Pa.). Injection pipettes are beveled to minimize clogging. Tip diameter of injection pipettes is 15-35 μm. Oocytes are microinjected with approximately 50 nL 1:10 ratio mixtures of cRNAs for rBIIa and beta 1 respectively.
[0135] Electrophysiology: Membrane current responses are recorded in frog Ringer solution containing 115 mM NaCl, 2 mM KCl, 1.8 mM CaCl 2 , 5 mM HEPES, pH 7.4. Electrical recordings are made using a conventional two-electrode voltage clamp (Dagan TEV-200) over periods ranging between 1-7 days following injection. The recording chamber is a simple gravity fed flow-through chamber (volume 100-500 mL depending on adjustment of aspirator). Oocytes are placed in the recording chamber, impaled with electrodes and continuously perfused (5-15 mL min −1 ) with frog Ringer's solution. The tested compounds are applied by bath perfusion.
[0136] Voltage protocols for evoking sodium channel currents: The standard holding potential for whole oocyte clamp is −120 mV. Standard current-voltage relationships are elicited by 40 ms depolarizing steps starting from −60 mV to +50 mV in 10 mV increments. Peak currents are measured as the maximum negative current after depolarizing voltage steps. The voltage from maximum current response is noted and used for the next voltage protocol.
[0137] The purpose is to find compounds that are state dependent modifiers of neuronal sodium channels. Preferably, the compounds have a low affinity for the rested/closed state of the channel, but a high affinity for the inactivated state. The following voltage protocol is used to measure a compounds affinity for the inactivated state. Oocytes are held at a holding potential of −120 mV. At this membrane voltage, nearly all of the channels are in the closed state. Then a 4 second depolarization is made to the voltage where the maximum current is elicited. At the end of this depolarization, nearly all the channels are in the inactivated state. A 10 ms hyperpolarizing step is then made in order to remove some channels from the inactivated state. A final depolarizing test pulse is used to assay the sodium current after this prolonged depolarization (see analysis below). Sodium currents are measured at this test pulse before and after the application of the tested compound. Data is acquired using PCLAMP 8.0 software and analyzed with CLAMPFIT software (Axon instruments).
[0138] Data analysis: Apparent inhibition constants (K; values) for antagonists are determined from single point inhibition data using the following equation (a generalized form of the Cheng-Prusoff equation) (Leff, P. and I. G. Dougall, TiPS 14:110-112 (1993)).
K i =( FR/ 1− FR )*[drug] Eq. 1
[0139] Where FR is the fractional response and is defined as sodium current elicited from the final depolarizing test pulse prior to application of the drug divided by the sodium current measured in the presence of the drug. [drug] is the concentration of the drug used.
[0140] Drugs: Drugs are initially made up at concentrations of 2-10 mM in DMSO. Dilutions are then made to generate a series of DMSO stocks over the range 0.3 μM to 10 mM—depending upon the potency of the compound. Working solutions are made by 1000-3000 fold dilution of stocks into Ringer. At these dilutions DMSO alone has little or no measurable effects on membrane current responses. DMSO stocks of drugs are stored in the dark at 4° C. Ringer solutions of drugs are made up fresh each day of use.
[0141] Compositions within the scope of this invention include all compositions wherein the compounds of the present invention are contained in an amount that is effective to achieve its intended purpose. While individual needs vary, determination of optimal ranges of effective amounts of each component is within the skill of the art. Typically, the compounds can be administered to mammals, e.g. humans, orally at a dose of 0.0025 to 50 mg/kg, or an equivalent amount of the pharmaceutically acceptable salt thereof, per day of the body weight of the mammal being treated for epilepsy, neurodegenerative diseases, anesthetic, arrhythmia, manic depression, and chronic pain. For intramuscular injection, the dose is generally about one-half of the oral dose.
[0142] In the method of treatment or prevention of neuronal loss in global and focal ischemia, brain and spinal cord trauma, hypoxia, hypoglycemia, status epilepsy and surgery, the compound can be administrated by intravenous injection at a dose of about 0.025 to about 10 mg/kg.
[0143] The unit oral dose can comprise from about 0.01 to about 50 mg, preferably about 0.1 to about 10 mg of the compound. The unit dose can be administered one or more times daily as one or more tablets each containing from about 0.1 to about 10, conveniently about 0.25 to 50 mg of the compound or its solvates.
[0144] In addition to administering the compound as a raw chemical, the compounds of the invention can be administered as part of a pharmaceutical preparation containing suitable pharmaceutically acceptable carriers comprising excipients and auxiliaries, which facilitate processing of the compounds into preparations that can be used pharmaceutically. Preferably, the preparations, particularly those preparations which can be administered orally and which can be used for the preferred type of administration, such as tablets, dragees, and capsules, and also preparations which can be administered rectally, such as suppositories, as well as suitable solutions for administration by injection or orally, contain from about 0.01 to 99 percent, preferably from about 0.25 to 75 percent of active compound(s), together with the excipient.
[0145] Also included within the scope of the present invention are the non-toxic pharmaceutically acceptable salts of the compounds of the present invention. Acid addition salts are formed by mixing a solution of the particular hydantoins of the present invention, with a solution of a pharmaceutically acceptable non-toxic acid such as, but not limited to: acetic acid, benzoic acid, carbonic acid, citric acid, dichloroacetic acid, dodecylsulfonic acid, 2-ethylsuccinic acid, fumaric acid, glubionic acid, gluconic acid, hydrobromic acid, hydrochloric acid, 3-hydroxynaphthoic acid, isethionic acid, lactic acid, lactobionic acid, levulinic acid, maleic acid, malic acid, malonic acid, methanesulfic acid, methanesulfonic acid, nitric acid, oxalic acid, phosphoric acid, propionic acid, sulfuric acid, sulfamic acid, saccharic acid, succinic acid, tartaric acid, and the like. Basic amine salts are formed by mixing a solution of the hydantoin compounds of the present invention with a solution of a pharmaceutically acceptable non-toxic acid, such as those listed above, preferably, hydrochloric acid or carbonic acid.
[0146] The pharmaceutical compositions of the invention can be administered to any animal that may experience the beneficial effects of the compounds of the invention. Foremost among such animals are mammals, e.g., humans and companion animals such as, dogs and cats, although the invention is not intended to be so limited.
[0147] The pharmaceutical compositions of the present invention can be administered by any means that achieve their intended purpose. For example, administration can be by parenteral, subcutaneous, intravenous, intramuscular, intraperitoneal, transdermal, or buccal routes. Alternatively, or concurrently, administration can be by the oral route. The dosage administered will be dependent upon the age, health, and weight of the recipient, kind of concurrent treatment, if any, frequency of treatment, and the nature of the effect desired.
[0148] The pharmaceutical preparations of the present invention are manufactured in a manner that is itself known, for example, by means of conventional mixing, granulating, dragee-making, dissolving, or lyophilizing processes. Thus, pharmaceutical preparations for oral use can be obtained by combining the active compounds with solid excipients, optionally grinding the resulting mixture and processing the mixture of granules, after adding suitable auxiliaries, if desired or necessary, to obtain tablets or dragee cores.
[0149] Suitable excipients are, in particular, fillers such as saccharides, for example lactose or sucrose, mannitol or sorbitol, cellulose preparations and/or calcium phosphates, for example tricalcium phosphate or calcium hydrogen phosphate, as well as binders such as starch paste, using, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, tragacanth, methyl cellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose, and/or polyvinyl pyrrolidone. If desired, disintegrating agents can be added such as the above-mentioned starches and also carboxymethyl-starch, cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof, such as sodium alginate. Auxiliaries are, above all, flow-regulating agents and lubricants, for example, silica, talc, stearic acid or salts thereof, such as magnesium stearate or calcium stearate, and/or polyethylene glycol. Dragee cores are provided with suitable coatings that, if desired, are resistant to gastric juices. For this purpose, concentrated saccharide solutions can be used, which can optionally contain gum arabic, talc, polyvinyl pyrrolidone, polyethylene glycol and/or titanium dioxide, lacquer solutions and suitable organic solvents or solvent mixtures. In order to produce coatings resistant to gastric juices, solutions of suitable cellulose preparations such as acetylcellulose phthalate or hydroxypropymethyl-cellulose phthalate, are used. Dye stuffs or pigments can be added to the tablets or dragee coatings, for example, for identification or in order to characterize combinations of active compound doses.
[0150] Other pharmaceutical preparations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer such as glycerol or sorbitol. The push-fit capsules can contain the active compounds in the form of granules which can be mixed with fillers such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds are preferably dissolved or suspended in suitable liquids, such as fatty oils, or liquid paraffin. In addition, stabilizers can be added.
[0151] Possible pharmaceutical preparations, which can be used rectally, include, for example, suppositories, which consist of a combination of one or more of the active compounds with a suppository base. Suitable suppository bases are, for example, natural or synthetic triglycerides, or paraffin hydrocarbons. In addition, it is also possible to use gelatin rectal capsules which consist of a combination of the active compounds with a base. Possible base materials include, for example, liquid triglycerides, polyethylene glycols, or paraffin hydrocarbons.
[0152] Suitable formulations for parenteral administration include aqueous solutions of the active compounds in water-soluble form, for example, water-soluble salts and alkaline solutions. In addition, suspensions of the active compounds as appropriate oily injection suspensions can be administered. Suitable lipophilic solvents or vehicles include fatty oils, for example, sesame oil, or synthetic fatty acid esters, for example, ethyl oleate or triglycerides or polyethylene glycol-400 (the compounds are soluble in PEG-400). Aqueous injection suspensions can contain substances which increase the viscosity of the suspension, and include, for example, sodium carboxymethyl cellulose, sorbitol, and/or dextran. Optionally, the suspension can also contain stabilizers.
[0153] The following examples are illustrative, but not limiting, of the method and compositions of the present invention. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in clinical therapy and which are obvious to those skilled in the art are within the spirit and scope of the invention.
EXAMPLE 1
[0154] Preparation of Hydantoins by Parallel Synthesis
[0155] Wang resin (i.e., 4-benzyloxybenzyl alcohol polystyrene) (6 g, 5.34 mmol) is placed in 250 mL of peptide vessel. Dimethylformamide (DMF) (70 mL) and F-moc glycine (9.6 g, 32.4 mmol) are added, followed by dicarbazine (DIC) (6 equiv.) and dimethylaminopyridine (DMAP) (0.5 equiv.). The reaction vessel is secured on a shaker table and allowed to agitate overnight. The resin is then washed with DMF (6×70 mL), MeOH (4×70 mL), and dichloromethane (i.e., DCM) (6×70 mL) and the solvent is removed under reduced pressure to give resin 1.
[0156] After removal of the Fmoc protecting group with 20% piperidine in DMF, the free amine 2 is reacted with an appropriate aldehyde (e.g., 4-(4-fluorophenoxy benzaldehyde) in dichloroethane (DCE) and in the presence of Na(OAc) 3 BH (8 equiv.) thereby resulting in the formation of resin bound compound 3. The resin is then washed with H 2 O (1×70 mL), DMF (6×70 mL), MeOH (4×70 mL), and DMC (6×70 mL). The resin is then dried under vacuum overnight.
[0157] Resin 3 (300 g, 0.27 mmol) is then treated with a 0.18 M solution of triphosgene (3 equiv.) in DCM, in the presence of pyridine, resulting in the formation of carbonyl chloride compound 4. Compound 4 is agitated for about 3 hours and washed with DCM. Compound 4 is then suspended in a 0.5 M solution of pyridine (10 equiv.), then treated with an appropriate amine (e.g., 1-(2-aminoethyl)-piperidine) (10 equiv.) and agitated for about 15 hours. Upon release from the resin support, the released compound undergoes ring closure to form the hydantoin product 6, in solution. The solvent is removed from the hydantoin product and the product is washed with DCM and filtered. The resulting filtrate is evaporated and the hydantoin product 6 is recovered in solid form. The recovered product is purified by flash column chromatography.
[0158] The compounds listed in Table 1 were prepared according to this parallel synthesis. These compounds were tested in the electrophysiological assay described above and apparent inhibition constants (expressed as K i values) were determined. The compounds listed in Table 1 have K i values of between 290 nM and 980 nM. The data demonstrates that compounds of the invention are potent blockers of the sodium channel.
TABLE 1 REPRESENTATIVE HYDANTOIN COMPOUNDS OF THE INVENTION n A A′ R R 1 R 2 NMR Data 1 O O H 1 H NMR (400 MHz, CD 3 OD): δ 1.32 (s, 1H), 1.45 (bs, 2H), 1.55 (bs, 4H), 2.43-2.55 (bd, 5H), 3.72 (m, 2H), 3.77 (s, 2H), 4.50 (s, 2H), 6.99 (m, 6H), 7.15 (t, 2H). 1 O O H 1 H NMR (400 MHz, CD 3 OD): δ 1.31 (bs, 2H), 1.55 (bs, 4H), 2.45 (bs, 4H), 2.55 (t, 2H), 3.72 (m, 4H), 4.57 (s, 2H), 5.05 (s, 2H), 6.99 (t, 2H), 7.11 (t, 2H), 7.40 (m, 5H). 1 O O H 1 H NMR (400 MHz, CD 3 OD): δ 1.33 (bs, 2H), 1.57 (bs, 4H), 2.35 (bs, 4H), 2.56 (bd, 2H), 3.65 (t, 2H), 3.79 (s, 2H), 4.58(s, 2H), 6.99 (t, 2H), 7.05 (t, 1H), 7.11 (t, 1H), 7.21 (t, 1H), 7.41 (m, 2H), 7.51 (m, 1H). 1 O O H 1 H NMR (400 MHz, CD 3 OD): δ 1.32 (bd, 2H), 1.45 (bt, 4H), 2.41 (bs, 4H), 2.51 (bt, 2H), 3.67 (m, 2H), 3.77 (s, 2H) , 4.60 (s, 2H), 6.85 (m, 1H), 6.99 (m, 2H), 7.15 (m, 2H), 7.41 (bm, 2H). 1 O O H 1 H NMR (400 MHz, CD 3 OD): δ 1.29 (bd, 2H), 1.51 (bt, 4H), 2.39-2.61 (bd, 6H), 3.62 (t, 2H), 3.72 (s, 2H), 4.51 (s, 2H), 6.99-7.07 (m, 5H), 7.12 (t, 1H), 7.45 (m, 3H). 1 O O H 1 H NMR (400 MHz, CD 3 OD): δ 1.32 (bs, 2H), 1.51 (bs, 4H), 2.41-2.51 (bd, 5H), 3.72 (t, 4H), 4.67 (s, 2H), 5.11 (s, 2H) , 6.88 (t, 3H), 6.95 (m, 2H), 6.99 (m, 1H), 7.25-7.48 (m, 6H).
[0159] Having now fully described this invention, it will be understood by those of ordinary skill in the art that the same can be performed within a wide and equivalent range of conditions, formulations and other parameters without affecting the scope of the invention or any embodiment thereof.
[0160] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
[0161] All patents and publications cited herein are fully incorporated by reference herein in their entirety. | This invention relates to aryl substituted hydantoins of Formula I:
or a pharmaceutically acceptable salt, prodrug or solvate thereof, wherein n, A, A′, R, R 1 and R 2 , are defined in the specification. The invention is also directed to the use of compounds of Formula I for the treatment of neuronal damage following global and focal ischemia, for the treatment or prevention of neurodegenerative conditions such as amyotrophic lateral sclerosis (ALS), and for the treatment, prevention or amelioration of both acute or chronic pain, as antitinnitus agents, as anticonvulsants, and as antimanic depressants, as local anesthetics, as antiarrhythmics and for the treatment or prevention of diabetic neuropathy. | 2 |
FIELD OF INVENTION
This invention relates to the synthesis of various α-ω substituted sexithiophenes which have significant solubility in common organic solvents suitable for solvent casting and their use as the semiconducting channel in organic thin-film field-effect transistors.
BACKGROUND OF THE INVENTION
Thin film transistors, known as TFT's are widely used as switching elements in electronics, most notably for large area applications such as active matrix liquid crystal displays, smart cards etc. The Thin Film Transistor (TFT) is an example of a field effect transistor (FET). The best known example of an FET is the MOSFET (Metal-Oxide-Semiconductor-FET), today's conventional switching element for high speed applications.
Presently, TFT's in most devices are made using amorphous silicon as the semiconductor. Amorphous silicon provides a less expensive alternative to crystalline silicon—a necessary condition for reducing the cost of transistors in large area applications. Application of amorphous silicon is limited to low speed devices, since its mobility (0.1-0.5 cm 2 /V*sec) is 15-20 thousand times smaller than that of crystalline silicon. Even though amorphous silicon is cheaper to deposit than highly crystalline silicon, deposition of amorphous silicon requires relatively costly processes, such as plasma enhanced chemical vapor deposition, and high temperatures (˜360° C.) to achieve electrical characteristics sufficient for display applications.
In the past decade organic semiconductors have received much attention as potential semiconductor channels in TFTs, for example, U.S. Pat. No. 5,347,144 to Garnier et al., entitled “Thin-Layer Field-Effect Transistors with MIS Structure Whose Insulator and Semiconductors Are Made of Organic Materials”. Organic materials (small molecules, short-chain oligomers and polymers) may provide a less expensive alternative to inorganic materials (e.g., amorphous silicon) for TFT applications as they are simpler to process, especially those that are soluble in organic solvents and therefore can be applied to large areas by far less expensive processes, such as spin-coating, dip-coating and microcontact printing. Furthermore organic materials may be deposited at low temperatures opening up a wider range of substrate materials including plastics for flexible electronic devices.
Several short-chain and oligomeric organic materials have been synthesized (e.g., α-sexithiophene) and have demonstrated mobilities close to amorphous silicon (0.1-0.6 cm 2 /V*sec); however, these relatively high mobilities have only been achieved by high-temperature vacuum deposition, since most of these compounds are not soluble in organic solvents. Some soluble long-chain organic compounds (e.g., polyalkylthiophenes) have been synthesized which have mobilities of 0.001-0.01 cm 2 /V*sec, but these materials usually have low on-off ratios, they must be applied under an atmosphere of inert gas and they must be extensively treated with base to reduce unintentional dopants introduced during polymerization to show semiconducting effects.
Accordingly, it is an object of this invention to synthesize soluble derivatives of the oligomer sexithiophene which are symmetrically substituted at the α- and ω-positions with various functional groups.
It is another object of this invention to use these derivatives of sexithiophene as low-cost, low-temperature alternatives to amorphous silicon as the semiconducting component in TFT devices.
SUMMARY OF THE INVENTION
A broad aspect of the present invention are soluble derivatives of sexithiophene in which terminal carbons are substituted with various polar groups such as phosphonic esters, phosphonic acids, phosphonates, carboxylic acids, carboxylates, amines, amides, carbamates, and alcohols, each separated from the terminal thiophene rings by one or more methylene groups, are synthesized. An TFT device in accordance with the second objective of this invention employs films of the above sexithiophene derivatives as the semiconducting component. These organic semiconductors are dissolved in common organic solvents and applied to the surface of a substrate using inexpensive, low-temperature solution-based processing such as spin-coating, dip-coating, drop-casting, or microcontact printing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the synthetic scheme by which all substituted sexithiophenes of this invention are synthesized.
FIG. 2 is a cross-sectional view of the TFT structure incorporating a sexithiophene derivative of this invention as the semiconducting channel.
FIG. 3 illustrates elements of an alternative TFT structure
FIG. 4 is a plot of I D versus V DS for a TFT with sexithiophenedibutylphosphonate as the active semiconducting material.
FIG. 5 is a plot of I D versus V G for a TFT with sexithiophenedibutylphosphonate as the active semiconducting material.
DETAILED DESCRIPTION OF THE INVENTION
Part A: Synthesis of Sexithiophene Derivatives
This invention describes the synthesis of various derivatives of sexithiophene (7 R=H, n=0), which are soluble in common organic solvents at room temperature. Application of these compounds as the semiconducting components of an TFT device is also described in this invention.
The synthetic scheme as shown in FIG. 1 employs two common steps for all derivatives. The first is conversion of substituted bromothiophenes 2 to substituted terthiophenes 4 via the palladium-catalyzed Stille coupling reaction as described by Frechet et al. ( J. Am. Chem. Soc. 1998, 120, 10990) the teaching which is incorporated herein by reference. The second step is an improved Ullmann coupling of bromo- or iodoterthiophenes of structure 5 to the desired sexithiophene derivatives 6. The starting material for the synthesis of diphosphonic ester 6a and dicarboxylic ester 6c was commercially available 4-(2-thienyl)butyric acid 1a. Esterification of 1a with dimethoxypropane gave the methyl ester 1b quantitatively. Lithium aluminum hydride reduction of 1b, followed by bromination, gave the corresponding bromobutylthiophene 1d, which was converted to phosphonatic ester 1e by the Arbuzov reaction. NBS bromination of 1e gave phosphonic ester 2a. A Stille coupling of 2a with tributylstannylbithiophene 3 afforded terthiophenebutylphosphonate 4a.
The standard method for the preparation of sexithiophene has been monometallation (monolithiation) of terthiophene derivatives followed by oxidative coupling of the lithiated terthiophene by various oxidizing agents, most notably by copper chloride as described by Garnier et al. ( J. Am. Chem. Soc. 1993, 115, 8716) the teaching which is incorporated herein by reference. Although this method has been satisfactory with moderate yields, it cannot be used for terthiophene derivatives having base (e.g., butyllithium) sensitive groups like carboxylic esters, amides etc. We have devised a new procedure for the coupling of terthiophene derivatives which is universal for all substituted terthiophenes. It involves the halogenation (bromination or, preferably, iodination) of terthiophene derivatives, which are then coupled via a palladium-catlayzed Ullmann-type coupling in accordance with the procedure described by Rawal et al. ( Organic Lett. 2000, 1(8), 1205) the teaching which is incorporated herein by reference, resulting in good yields of the corresponding sexithiophene derivatives. Accordingly, terthiophenebutylphosphonate 4a was selectively iodinated at the α-carbon of the terminal ring by reaction with iodine in the presence of mercuric acetate to give iodoterthiophenebutylphosphonate 5a. The palladium-catalyzed Ullmann coupling of 5a afforded sexithiophene 6a. Compound 6a is highly soluble in chlorinated organic solvents such as methylene chloride, chlorform, trichloroethylene etc., and can be applied on any substrate by spin-coating, dip-coating, drop-casting or any other methods which are used for application of thin films of organic materials from solution. The R functionality in structure 6 can be chosen from any polar functionality which might enhance the solubility and/or hydrogen bonding of sexithiophene derivatives. Following the procedure outlined above, sexithiophene derivatives containing carboxylic esters and acids were also synthesized. Carboxylic ester 1b was brominated with NBS to give 2b, which was coupled with tributyltinbithiophene 3 to give terthiophene 4b. Iodination of 4b yielded 5b, which was coupled using the palladium-catalyzed Ullmann reaction to afford sexithiophene 6b in high yield. Although the synthesis of two examples of sexithiophene (with phosphonate ester and carboxylic ester groups) is described, the same procedure can easily be used to prepare sexithiophene compounds substituted with other polar functionalities. For example, R in structure 6 can be chosen to be hydroxyl, amine, mercaptan, amides, carbamate, aldehyde, ketone, sulfonic acid, boronic acid or esters. At the same time, the methylene spacer groups which separate these functionalities from the thiophene rings may vary from 0 to 18 methylene groups, preferably from 1 to 10 methylene units.
EXAMPLE I
Detailed Synthetic Procedure for synthesis of 6a
Methyl-4-(2-thienyl)butyrate 1b Concentrated hydrochloric acid (0.5 mL) was added to a solution of 4-(2-thienylbutyric acid) (10.0 g, 0.058 mol) in 100 mL of 2,2-dimethoxypropane and the resulting solution was stirred at room temperature for 48 hours. Excess dimethoxypropane was evaporated, and the oily residue was distilled under vacuum (105° C., 0.15 mm Hg) to yield methyl ester 1b (10.2 g, 95%) as a colorless oil. IR: 1732 cm −1 (ester carbonyl). 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.11 (m, 1H, Ar—H), 6.91 (m, 1H, Ar—H), 6.78 (m, 1H, Ar—H), 3.66 (s, 3H, OCH 3 ), 2.87 (t, 2H, CH 2 CO 2 Me), 2.36 (t, 2H, Ar—CH 2 ), 2.00 (tt, 2H, CH 2 CH 2 CH 2 ).
2-(4-Hydroxybutyl)thiophene 1c. A 2.5 M solution of lithium aluminum hydride in THF (10 mL) was slowly added to a solution of methyl ester 1b (7.30 g, 0.04 mol,) in 100 mL of anhydrous THF. After completion of the addition, the solution was refluxed for four hours, then cooled to room temperature. Hydrochloric acid (10%, 25 mL) was then slowly added, and the resulting mixture was heated for another 30 minutes. After cooling to room temperature, diethyl ether (100 mL) was added, the organic layer was separated and washed with brine, dried with anhydrous magnesium sulfate. Evaporation of the solvent gave the alcohol 1c (5.4 g, 90%) as a colorless oil. 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.12 (m, 1H, Ar—H), 6.92 (m, 1H, Ar—H), 6.79 (m, 1H, Ar—H), 3.62 (t, 2H, CH 2 OH), 2.86 (t, 2H, Ar—CH 2 ), 2.30 (s, 1H, OH), 2.00 (m, 4H, CH 2 CH 2 CH 2 CH 2 ).
2-(4-Bromobutyl)thiophene 1d. Chlorotrimethylsilane (2.60 g, 0.025 mol) was added to a solution of lithium bromide (1.75 g, 0.02 mol) in 100 mL of anhydrous acetonitrile and the mixture was stirred under nitrogen for 30 minutes. To this solution was added, via syringe, a solution of alcohol 1c (1.56 g, 0.01 mol) in 10 mL of acetonitrile and the resulting solution refluxed overnight. The solution was cooled to room temperature, the solvent was evaporated under reduced pressure and the residue was taken up in diethyl ether. The solid was removed by filtration, and the filtrate was evaporated to give an oily brown residue which was purified by flash chromatography through a column of silica gel using hexane as the eluent, to give bromobutylthiophene 1d (1.9 g, 88%) as a colorless oil. 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.10 (m, 1H, Ar—H), 6.91 (m 1H, Ar—H), 6.78 (m, 1H, Ar—H), 3.41 (t, 2H, CH 2 Br), 2.85 (t, 2H, Ar—CH 2 ), 1.85 (m, 4H, CH 2 CH 2 CH 2 CH 2 ).
Diethyl-4-(2-thienyl)butylphosphonate 1e. A solution of 1d (4.58 g, 0.02 mol) in 20 mL of triethylphosphite was heated at 160° C. for 20 hours, with nitrogen bubbling directly into the solution. The solution was cooled to room temperature and 50 mL of water was added; the resulting mixture was stirred for 4 hours. The product was extracted with methylene chloride, the organic layer was separated and washed with brine, then dried over anhydrous magnesium sulfate. Evaporation of the solvent yielded an oily residue, which was distilled under vacuum (0.12 mm Hg, 135° C.) to give 1e as a colorless oil (6.0 g, 82%). 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.06 (m, 1H, Ar—H), 6.85 (m, 1H, Ar—H), 6.72 (m, 1H, Ar—H), 4.03 (m, 4H, POCH 2 CH 3 ), 2.79 (t, 2H, Ar—CH 2 ), 1.72 (m, 6H, CH 2 CH 2 CH 2 P), 1.26 (t, 6H, POCH 2 CH 3 ).
Diethyl-4-(2-bromothienyl)butylphosphonate 2a. N-bromosuccinimide (1.78 g, 0.01 mol) was added portionwise to a solution of 1e (2.78, 0.01 mol) in dimethylformamide (20 mL) and the solution was stirred at room temperature overnight. Diethyl ether (50 mL) was added to the reaction mixture, which was then washed twice (50 mL each) with water, once with brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 2a as light yellow oil (3.2 g, 87%). 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ6.80 (d, 1H, Ar—H), 6.49 (d, 1H, Ar—H), 4.03 (m, 4H, POCH 2 CH 3 ), 2.72 (t, 2H, Ar—CH 2 ), 1.67 (m, 6H, CH 2 CH 2 CH 2 P), 1.27 (t, 6H, POCH 2 CH 3 ).
Diethyl-4-[5-(2,2′:5′2″)terthienyl]butylphosphonate 4a. 5-tributylstannyl-(2,2′)bithiophene (4.54 g, 0.01 mol) was added to a solution of 2a (3.55 g, 0.01 mol) in anhydrous DMF (30 mL) under a nitrogen atmosphere. To this solution was added 500 mg of bis(triphenylphosphine)palladium(II)chloride and the mixture was heated to 60° C. for 3 hours and then stirred at room temperature for 20 hours. Diethyl ether (100 mL) was added and the mixture was washed several times with water and then with brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave a yellow-orange solid residue, which was chromatographed on column of silica gel. Elution with ethyl acetate gave, after evaporation of the solvent, an orange solid (3.0 g, 83%). Crystallization from hexane afforded analytically pure 4a. m.p.: 92° C. 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.16-6.94 (m, 6H, Ar—H), 6.66 (m, 1H, Ar—H), 4.08 (m, 4H, POCH 2 CH 3 ), 2.79 (t, 2H, Ar—CH 2 ), 1.75 (m, 6H, CH 2 CH 2 CH 2 P), 1.29 (t, 6H, POCH 2 CH 3 ).
Diethyl-4-[5″-iodo-5-(2,2′:5′2″-terthienyl)butylphosphonate 5a. Mercuric acetate (0.954 g, 3 mmol) was added to a solution of 4a (2.28 g, 5 mmol) in anhydrous DMF (20 mL) and the mixture was stirred at room temperature for one hour under nitrogen. Iodine (1.27 g, 5 mmol) was then added to the solution portionwise over a period of 30 minutes and the mixture stirred at room temperature for 20 hours. Diethyl ether (50 mL) was added and the solution was washed several times with water and then with brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave an orange solid residue which was crystallized from a mixture of toluene and hexane (50:50 v:v) to give 5a (2.5 g, 91%) as an orange microcrystalline compound, m.p.: 115° C. 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.12 (m, 1H, Ar—H), 6.94 (m, 3H, Ar—H), 6.78 (m, 1H, Ar—H), 6.66 (m, 1H, Ar—H), 4.05 (m, 4H, POCH 2 CH 3 ), 2.79 (t, 2H, Ar—CH 2 ), 1.70 (m, 6H, CH 2 CH 2 CH 2 P), 1.29 (t, 6H, POCH 2 CH 3 ).
Bis-Diethyl-4-[(5,2′″″-(2,2′:5′2″:5″,2′″:5′″,2″″:5″″,2′″″-sexithiophenediyl)-butylphosphonate 6a. A solution of palladium acetate (20 mg, 0.09 mmol) and tri-p-tolylphosphine (30 mg, 0.1 mmol) in anhydrous DMF (10 mL) was added to a mixture of 5-iodo-2,2′:5′,2″-terthienylbutylphosphonate 5a (950 mg, 1.67 mmol), hydroquinone (160 mg, mmol) and cesium carbonate (700 mg, 2.1 mmol), and the mixture was deaerated by three freeze-thaw cycles and backfilled with nitrogen. The mixture was then heated at 70° C. for 4 hours, cooled to room temperature and then stirred further for 20 hours. The dark orange solid was separated by filtration, washed several times with diethyl ether, and dried in vacuo. Crystallization from 1,2-dichlorobenzene afforded 6a as a bright red-orange microcrystalline product (900 mg, 62%). m.p. (measured by DSC): 245° C.
EXAMPLE II
Detailed Synthetic Procedure for Synthesis of 6b
Methyl-4-(5-bromo-2-thienyl)butyrate 2b. The NBS bromination of 1b according to the procedure outlined for the preparation of 2a gave >90% yield of 2b as a colorless oil. b.p.: 138° C. at 0.15 mmHg. 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ6.82 (d, 1H, Ar—H), 6.52 (d, 1H, Ar—H), 3.64 (s, 3H, OCH 3 ), 2.79 (t, 2H, CH 2 CO 2 Me), 2.33 (t, 2H, Ar—CH 2 ), 1.93 (tt, 2H, CH 2 CH 2 CH 2 ).
Methyl-4-(5-2,2′:5′,2″-terthienyl)butyrate 4b. The Stille coupling reaction of 2b with 5-tributylstannyl-2,2″-bithiophene 3 according to the procedure outlined for the preparation of 4a gave the terthiophene derivative 4b in 80% yield as a fluorescent yellow solid, m.p.: 81° C. 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.20-7.13 (m, 2H, Ar—H), 7.04-6.95 (m, 4H, Ar—H), 6.68 (m, 1H, Ar—H), 3.66 (s, 3H, OCH 3 ), 2.84 (t, 2H, CH 2 CO 2 Me), 2.38 (t, 2H, Ar—CH 2 ), 1.99 (tt, 2H, CH 2 CH 2 CH 2 ).
Methyl-4-[5-bromo-5″-(2.2′:5′,2″-terthienyl]butyrate 5b. NBS bromination of 4b following the procedure outlined for 4a gave 5b in >80% yield as a yellow-green solid. m.p.: 134° C. 1 H NMR (250 MHz, 25° C., CDCl 3 ): δ7.14 (m, 1H, Ar—H), 6.98 (m, 3H, Ar—H), 6.81 (m, 1H, Ar—H), 6.69 (m, 1H, Ar—H), 3.68 (s, 3H, OCH 3 ), 2.85 (t, 2H, CH 2 CO 2 Me), 2.39 (t, 2H, Ar—CH 2 ), 2.01 (tt, 2H, CH 2 CH 2 CH 2 ).
Sexithiophene 6b. A solution of tri-p-tolylphosphine (100 mg, 0.3 mmol) and palladium acetate (100 mg, 0.45 mmol) in 10 mL of anhydrous dimethylformamide was added to a mixture of 5b (600 mg, 1.25 mmol), hydroquinone (200 mg, 1.8 mmol) and cesium carbonate (400 mg, 1.25 mmol). The mixture was deaerated by three cycles of freeze-thaw, backfilled with nitrogen, and heated at 80° C. for 20 hours. The resulting black mixture was cooled to room temperature, the precipitate was filtered and washed thoroughly with ethanol and diethyl ether, and dried in vacuo. Crystallization from 1,2-dichlorobenzene afforded 6b as a red-orange crystalline compound. m.p.(DSC):
EXAMPLE III
Device Fabrication
The use of sexithiophene 6a as the semiconducting channel in a Thin Film Transistor (TFT) is exemplified as follows:
A thin film transistor was fabricated by spin coating (or drop casting) a solution of sexithiophene 6a in chloroform (2 mg/mL) on a highly doped silicon wafer, serving both as the gate electrode and substrate with a 500 nm thermally grown silicon dioxide as gate insulator and gold source and drain electrodes as shown in FIG. 2 . While FIG. 2 illustrates a typical TFT structure arrangement, alternative structures are contemplated as within the ambit of the invention. See FIG. 3 where the respective elements of an alternative TFT structure are illustrated. Alternative substrates include plastics such as polyimide and polycarbonate, which may be used to build flexible devices.
Preliminary data demonstrating the desired field-modulated conductance and current saturation for a TFT prepared with the soluble sexithiophene 6a are shown in FIGS. 4 and 5. The sexithiophene compound forms a p-channel transistor as shown in a plot of drain current, I D , versus source-drain voltage, V DS , as a function of gate voltage V G (FIG. 4 ). Device operation is modeled by standard field-effect transistor equations. Plots of I D and I D ½ versus gate voltage, V G (FIG. 5 ), at V DS =−100V are used to calculate the current modulation (I on /I off ) and field-effect mobility in the saturation regime. For this device, with a channel width of 1.5 mm and a channel length of 28 micrometers, the current modulation is greater than 10 4 and the field-effect mobility is 2.2*10 −3 cm 2 /V-sec. | In accordance with the first object of this invention soluble derivatives of sexithiophene in which terminal carbons are substituted with various polar groups such as phosphonic esters, phosphonic acids, phosphonates, carboxylic acids, carboxylates, amines, amides, carbamates, and alcohols, each separated from the terminal thiophene rings by one or more methylene groups, are synthesized. An TFT device in accordance with the second objective of this invention employs films of the above sexithiophene derivatives as the semiconducting component. These organic semiconductors are dissolved in common organic solvents and applied to the surface of a substrate using inexpensive, low-temperature solution-based processing such as spin-coating, dip-coating, drop-casting, or microcontact printing. | 2 |
RELATED APPLICATION
This is a division of application Ser. No. 927,006, filed July 24, 1978. This application is a continuation-in-part of my earlier filed U.S. patent application Ser. No. 719,017 filed Aug. 30, 1976 now U.S. Pat. No. 4,102,023 granted July 25, 1978. The disclosure and contents of which are entirely incorporated by reference herein.
BACKGROUND OF THE INVENTION
I have previously invented a contour shear rest for use in a plane shearing machine to simulate, in a three dimensional deep-pile fabric the effect obtained by sewing together small animal pelts, such as mink. The shear rest there provided has a contour surface made up of elements forming a mirror image of the desired contour. The contour surface is formed so that the length of the travel path of the fabric drawn across its face is uniform. See my co-pending U.S. application Ser. No. 719,017 which has now been assigned U.S. Pat. No. 4,102,023.
In endeavouring to utilize the contour shear rest of such invention for the commercial production of contour sheared deep pile fabrics, it was discovered that for purposes of continuously maintaining a precise interrelationship between a patterned web of high pile fabric and a contour shear device incorporating such contour shear bar, it was desirable to continuously make adjustments in the transverse alignment of the web relative to the contour shear work station. It was also desirable, during operation, to maintain a continuously variable but optimized longitudinal tension upon the web because thereby the transverse width of the patterned web could be influenced and hence bring and maintain the web into a desired exact transverse registration with the contours of the contour shear device. Inherent structural variations seemingly tend to occur in a continuous web of pile fabric so that it does not appear to be feasible to merely initially at a start up adjust the transverse alignment and longitudinal tension of a continuous web of pile fabric relative to a transversely extending work station since variations can develop during machine operation after the web has advanced even relatively short distances. Consequently, for purposes of plant operation, particularly an automated plant operation, it is desirable to have a control system for transversely aligning and continuously, variably longitudinally tensioning a continuous web relative to a transversely extending work station. So far as I am aware, this type of control problem has never previously been met or solved through the provision of an appropriate control system.
In addition, it has also been determined that when employing a contour shear device of the character above described, it is desirable to employ a contour electrifier for subsequent polishing operations. As those skilled in the art appreciate, a machine known as an electrifier is used in the processing of pile fabrics, fur, and similar yardage to place the fur or pile in a desired or proper finished condition. Generally speaking, the function of an electrifier is to brush, comb, beat, polish, and/or iron which is accomplished by the application to the pile or fur of a rapidly rotating heated roll which has a grooved surface. Work pieces are fed continuously to the roll with the pile or fur faced toward the roll and an apron of canvas or other suitable web support means which will insure the desired exposure of the pile to the electrifier cylinder is so mounted with respect to the roll that the fabric is fed between the apron or support means and the roll. Typically, the temperature of the surface of an electrifier roll is critically controlled.
In processing by an electrifier, a fabric which has been contour sheared by a contour shear device such as described in my above referenced invention, it has been found that undesirable variations in the product pile finished characteristics can be obtained owing to the inability of prior art electrifiers to conform in their surface application characteristics to pile contours. So far as I am aware, no one has heretofore succeeded in providing electrifiers whose working surfaces are adapted to conform to contours previously formed in a pile or fur work piece.
Further, it has now been determined that, in the processing of, for example, contour sheared high pile sliver knit fabrics, it would be desirable to use a train of contour processing units in some desired processing sequence with the individual processing units being either a contour shear device or a contoured electrifier device. Since problems of alignment, tensioning, and registration of web relative to contour processing unit can arise at each unit in such a train, it is desirable to have a system for controlling a continuously moving web being processed by a train of such contour processing units which permits the web to be aligned for all units with a minimum of control hardware. If, for example, a single separate control unit of the type necessary for achieving alignment, registration and tensioning, as desired, were necessary at each individual contour processing unit, manufacturing costs would apparently be substantially and undesirably increased. Hence, there is a need for using a single control system to simultaneously and effectively control a web during its passage past a plurality of contour processing units.
BRIEF SUMMARY OF THE INVENTION
The present invention provides apparatus and methods for overcoming the problems above described in utilizing contour shearing apparatus.
Thus, in one aspect, the present invention relates to a control system for web alignment, registration, and longitudinal tensioning along a web path relative to a work station transversely extending across said web path at a preset location therealong.
In another aspect, the present invention provides contoured electrifier apparatus suitable for the processing of contour sheared pile fabrics.
In another aspect, the present invention provides a control system of the type above indicated but which is adapted for use with a train of contour shearing devices such as a mixture of contour shearing units and contoured electrifier units.
In another aspect, the present invention provides processes for using apparatus as indicated above.
Other and further objects, purposes, advantages, aims, utilities, features and the like will be apparent to those skilled in the art from a reading of the present specification taken together with the drawings.
BRIEF DESCRIPTION OF DRAWINGS
In the Drawings:
FIG. 1 is a perspective view of one embodiment of a control system of the present invention for transversely aligning and longitudinally tensioning a continuous web relative to a transversely extending work station;
FIG. 2 is a transverse sectional view through a web member which has been processed through a contour shearing apparatus operated with the control system illustrated in FIG. 1;
FIG. 3 is a schematic transverse sectional view taken in the region of the control elements utilized in the control system of FIG. 1;
FIG. 4 is a view similar to FIG. 1 but showing an alternative embodiment of the control system of the present invention;
FIG. 5 is a perspective view of one embodiment of a contour electrifier of the present invention;
FIG. 6 is an enlarged fragmentary detail view transversely taken across a portion of a web member which has been initially contour sheared and then processed through a contoured electrifier of the type shown in FIG. 5;
FIG. 7 is an enlarged detail fragmentary view taken in the region VII--VII of FIG. 5;
FIG. 8 is an enlarged detailed fragmentary view taken along the line VIII--VIII of FIG. 7;
FIG. 9 is a transverse sectional view taken through the region IX--IX of FIG. 5 illustrating construction of the contoured electrifier roll;
FIG. 10 is a fragmentary elevational view taken along the line X--X of FIG. 9;
FIG. 11 is a view similar to FIG. 5 but showing an alternative embodiment of a contoured electrifier of the present invention;
FIG. 12 is a view similar to FIG. 9 but taken along the line XII--XII of FIG. 11;
FIG. 13 is a view similar to FIG. 10 but taken along the line XIII--XIII of FIG. 12;
FIG. 14 illustrates an embodiment of the present invention wherein a control system as provided herein is used to control the web path through and past two sequentially arranged contour processing units, the processing units being a contour shearing device and a contour electrifier device respectively;
FIG. 15 is a view similar to FIG. 14 but showing such control apparatus being employed to regulate the web path past and through each of three contour processing units;
FIG. 16 is a view similar to FIG. 14 but illustrating the utilization of two control units of the present invention in a sequential arrangement relative to one another, each control unit being employed to regulate the operation of three contour processing units in the manner as shown, for example, in FIG. 15; and
FIG. 17 is a view similar to FIG. 14 but illustrating the manner in which a control system of the present invention may be used to control five contour processing units simultaneously with such units being sequentially arranged relative to one another along a web pathway.
DETAILED DESCRIPTION
Control System
A web, such as a sliver knit high pile fur-type fabric is typically continuously moved from a plaited storage bin or any other suitable source through a processing apparatus, wherein a contour shearing means contours the web as it passes through the apparatus in the direction of movement generally indicated by the arrow marked on the web in FIG. 1. For present purposes, the contour shearing means can be considered to be similar to that disclosed and claimed in the above identified copending Norman C. Abler U.S. patent application Ser. No. 719,017, filed Aug. 30, 1976, now U.S. Pat. No. 4,102,023.
The web is pulled from the storage bin by a driving roller 20 and is then moved through a steering frame assembly 21. Steering frame assembly 21 includes a pair of training rollers 22 and 23 providing together a vertical run for the web 10. The steering frame 21 is pivotally mounted on a main frame 24 (shown fragmentarily) so that the frame 21 may be rotated about the pivot on an axis which is approximately tangent to the back edge of the roller 23. This pivoting is accomplished by a fluid cylinder 25 attached to a tongue which extends rearwardly of the pivot axis and the frame 21, underneath the web 10. The resultant skewing of the roller 23 (and roller 22) provides a steering influence upon the web 10 so that the web 10 is controllably moved transversely to a predetermined and controllable lateral position during continuous movements longitudinally of the web 10. Between the steering frame 21 (and roller 22 thereof) and the contour shearing cutter 30 is positioned a control system herein designated in its entirety by the numeral 31.
This control system 31, see, for example, FIG. 3, functions to sense at any given instant in time the spatial position of the edges of web 10 and to convert the position of the web edges into signals which are used to control transverse position of the web as well as the transverse width of the web all relative to predetermined standards suitable for operation of the contour shearing head 30. Surrounding the web 10 is a control chain 32 which is continuous and which is extended about a pair of sprockets 33 for orbital movements about the web 10. Each opposed edge of web 10 is provided with an edge sensor mechanism designated in its entirety by the numeral 35 and 36, respectively. These sensors 35 and 36 can be of any conventional construction. In the embodiment shown, a pneumatic pressure sensor is utilized. Sensor 35 is associated with an arm 37 which is connected to the bottom portion of the chain 32, and sensor 36 is connected to an arm 38 which, in turn, is connected to the upper portion of the chain 32. As will now be explained, during operation of the entire apparatus, the sensors 35 and 36 together with sensor 62 operate to maintain an equal spacing from opposed side edges of web 10, with the web 10 being centered on center line 39. Each of the sensors 35 and 36 generates an output signal which is utilized to maintain its respective sensor in a predetermined position relative to the adjacent opposed side edge of web 10, as shown in FIG. 3.
The signal generated by sensor 35 is fed by a line 40 to an (optional) amplifier 41 and then to a controller 42. Controller 42 compares the input signal from amplifier 41 to a set point signal and generates a difference signal which is discharged from controller 42 through a line 43 to a servo-valve unit 44. Accordingly, there are two or three possibilities for operation of servo-valve 44. By one possibility (optional) the signal fed thereto produces no change (no operation) of valve 44. In a second mode, the signal 43 fed to servo valve 44 causes the valve 44 to admit fluid to double acting control cylinder 45 whereby the piston 46 thereof moves to the right, thereby moving the rod 47 to the right. Rod 47 is terminally connected to an arm 48 which is rigidly connected to the chain 32; hence, the upper rim of chain 32 is thus moved to the right. By the third possibility, the signal fed to valve 44 by the line 43 causes the piston 46 to move to the left, and, by a similar sequence of steps, the chain 32 is moved to the left. Moving the chain 32 to the right causes the sensor 35 to move away from the associated edge of web 10, and, conversely, moving the chain 32 to the left causes the sensor 35 to move towards the associated edge of web 10. When sensor 35 is so caused to move, sensor 36 will also be caused to move in corresponding relationship with respect to web 10. As can be seen by those skilled in the art, any equipment means, such as pulleys and cable, or the like, can be used to cause the sensors 35 and 36 to so move in corresponding relationship to each other.
Similarly, the sensor 36 has its output signal fed via a line 51 to an (optional) amplifier 52, and hence to a controller 53 wherein the signal is compared to a set point signal, and a difference signal is discharged from controller 53 through a line 54 to a servo control valve 55 which, like the servo control valve 44, has two or three conditions of analogous operation. The servo control valve 55 operates a double acting control cylinder 25, as indicated above, to control the skewing movements of the web frame 21, as described above.
The coaction between the two sensors 35 and 36 is effective to maintain the web 10 centered on center line 39, and, accordingly, on the center of the contour shearing knife 30. Thus, the web 10 is always maintained centered on the cutter 30.
The web 10, though partially dimensionally stabilized, is such that tensioning the web 10 in a longitudinal direction reduces the width thereof to a predeterminable and predictable extent. Initially, the web 10, in its relaxed state, is equal to or greater than a predetermined effective width associated with the cutter 30. During continuous operation of the apparatus shown, for example, in FIG. 2, variations in machine operation, and in web construction, can occur so that a single setting with respect to longitudinal tension on the web 10 is generally insufficient to maintain exact desired registration between the cutter 30 and the web 10. Therefore, by the present invention, there is provided a variable tensioning means which enables the web 10 to be fed continuously through the cutter 30 at a constant transverse width in the vicinity of the cutter 30, as will now be described.
For purposes of achieving automatic tensioning by the present invention, an arm 60 is secured to chain 32. Arm 60 can be at any convenient position along the chain 32, but is here shown on the bottom side of the chain 32 at about the center line 39, for convenience. Not until the sensors 35 and 36 have moved to a predetermined location relative to opposed sides of web 10 with the web 10 being tensioned to produce a predetermined desired width thereof will the arm 60 itself be in a predetermined centered position. When the arm 60 is in its own centered position, which here happens to coincide with center line 39, and the arm 60 is connected to a sensor 62 by a connecting rod 61, the sensor 62 being conveniently a potentiometer or a linearly variable differential transformer or LVDT, a signal is generated by the sensing device 62 which is charged to a line 63. Line 63, in turn, connects with an amplifier 64, (optional) and the signal from amplifier 64 is fed directly to a controller 65. In the controller 65, the signal charged thereto is compared to a set point signal, and an output signal is generated which is charged to another line 66 which feeds the output signal to a servo motor 67. The servo motor 67 adjusts the output speed of a variable speed drive such as a variable diameter pulley or the like 68 which is drivably connected to the drive roller 20. In turn, the variable speed drive 68 is driven by a gear head motor 69. The gear head motor 69 is coupled to a down stream drive roller 70 which is beyond the cutter 30. Thus, the web 10 is maintained at the required tension between the respective rollers 70 and 20 whereby the tensioning on the web 10 in a longitudinal direction is such that at any given instant in time the transverse width of the web 10 has the desired predetermined constant width in the vicinity of the cutter 30. Obviously, by driving the roller 20 at a slightly reduced speed relative to some constant value or to the roll speed of the roller 70, the tension on the web 10 can be increased slightly, and vise versa. Thus, with the roller 20 moving at a decreased speed relative to roller 70, tensioning of the web 10 longitudinally is increased between these rollers. Conversely, if the speed of the roller 20 is increased slightly so that it comes closer to the speed of the roller 70, then tension longitudinally on the web 10 is decreased. Whenever the arm 60 is not on center because of the width of the web being larger or smaller than some predetermined value, the sensor 62 is generating an output signal which is representative of the deviation from center.
Through this arrangement the web width is adapted to be controlled without lateral mechanical restraint of the web, that is, without using any means, such as grippers, rollers or the like, for engaging the web edges for this purpose.
Obviously, the roller 70 must be driven at a greater speed than the roller 20 to maintain a tension longitudinally along the web 10. If the converse were true, then a surplus of webbing would be built up between the rollers 20 and 70, and tension would be lost altogether.
Referring to FIG. 4, there is seen another embodiment of a control system of the present invention which is similar to the embodiment shown in FIGS. 1 and 3 except that here a steering frame assembly 80 is oriented generally in a horizontal plane rather than the orientation in a generally vertical plane in the manner of the steering frame assembly 21, and it is shown located prior to the variable speed tension roller 20' rather than between the two tensioning rollers 20' and 70'.
In the embodiments of FIGS. 1 and 3 and the embodiment of FIG. 4, as those skilled in the art will appreciate, in place of the contour shearing means illustratively shown one can employ a contoured electrifier means such as one of the character herein described.
Contoured Electrifier with Flat Rest
Referring to FIGS. 5 and 7 through 10 there is seen one embodiment of an electrifier apparatus 100 of the present invention which is provided with a contoured electrifier roll. The apparatus employs an electrifier roll or cylinder 101 rotatably mounted in suitable pillow blocks 102 and 103 carried by a frame 104 (not detailed). A conventional motor (not shown) drives a tubular stub shaft 106 which is axially connected with the cylinder 101 by end plates (paired) 107 through V-belt 108 rotatably turning sheaves 109 keyed to shift 106. Operating speeds for the cylinder 101 can vary but normally fall in the range of from about 700 to 1400 rpm.
Cylinder 101 is suitably controllably heated internally by means of an electrical heating system such as the electrical heating system taught by Henry Martin in U.S. Pat. No. 3,641,635. Alternatively, a gas heating system can be used.
Extending longitudinally in axially spaced relationship to cylinder 101 is a work support bar or rest 111 which is suitably supported by frame members (not detailed). Work is illustratively being performed by the electrifier of this embodiment here on contour sheared high pile, sliver knit fabric 112 which is continuously moved in the direction shown by arrow 113 over a nip region 115 between circumferential surface portions 130 of cylinder 101 and bar 111. The width of the web of fabric 112 can vary widely, but illustratively and commonly falls in the range of from about 48 to 84 inches, depending upon the type of knitting equipment being used.
Referring to FIG. 6, and as those skilled in the art will appreciate, the fabric 112 has a base 114 of woven or knitted material and a pile 116 of natural or synthetic fibers which are joined to the base 114. Here, the pile 116 has previously been subjected to a contour shearing operation using, preferably, a contour shearing device for pile fabrics, such as shown and described in my above referenced Abler U.S. patent application Ser. No. 719,017, filed Aug. 30, 1976. As those skilled in the art will appreciate, the electrifier 100 can also be used to work upon many types of natural or synthetic fabrics, furs, and other webs of material, if desired.
The fabric 112 is advanced by a conventional work feeding mechanism (not detailed) through the electrifier 100 with the pile 116 moving against the circumferential surface 130 of cylinder 101. The work feeding mechanism can be the same as previously described here-in for feeding work through the contour shear.
Preferably, the electrifier 100 is operated in cooperation with a control system, such as one provided by the present invention, so as to provide for automatically regulating transverse variations in web width, alignment, and registration of the fabric 112 with the cylinder 101 and its contours.
Cylinder 101 is commonly hollow and has a longitudinal length which is determined by the maximum width of the fabric being processed in any given instance, the capacity of the equipment, and the like. The outside diameter of the cylinder 101 can range typically from around 8 to 24 inches with about 12 inches being a particularly preferred and useful distance for peak diameters. The thickness of the wall of cylinder 101 can vary, but typically is in the range of from about 5/8 to 11/2 inches. The cylinder 101 is conveniently formable by casting a metal, such as steel, or the like, followed by machining operations to complete circumferential surface contours to desired specifications. The circumferential surface portions of the cylinder 101 are formed so as to comprise a plurality of longitudinally spaced, circumferentially extending, radially projecting ridged portions 117. Between adjacent pairs of ridge peaks 117, the cross sectional diameters of the cylinder 101 progressively decline to minimal cylinder diameters, as is illustrated, for example, in the regions 118 of the cylinder 101. The configuration of the peaks 117, and of the valleys 118, can, of course, vary from one cylinder to another, depending upon the wishes of the user, the type of contour sheared fabric being worked, desired operating parameters, and the like.
Formed in exterior circumferential surfaces of the cylinder 101 are helically arranged, longitudinally extending grooves 119 and 121. The direction of rotation of cylinder 101 is illustrated by arrow 121a which establishes the groove 119 as being a right-hand groove in terms of the direction in which loose fibers, moisture, or the like, will be laterally moved by the species of "combing" action of this groove upon the fabric 112 during operation of the electrifier 100. Groove 121 is a left-hand groove since it "works" the surface of fabric 112 toward the left during operation of electrifier 100.
The surface material of the cylinder 101 is cut away to form the grooves 119 and 121. The contour of a groove 119 or 121 may vary widely but in a preferred form is illustrated, for example, in FIGS. 7, 9 and 10. The "trailing" wall of each groove 119 and 121 is abruptly radially shouldered throughout substantially the entire respective lengths of such grooves, and a metal wear blade 122 and 123, respectively, is mounted securely against such shoulder by means of screws 124. The exposed corner of each blade 122 and 123 is preferably rounded slightly, as shown at R in FIG. 8, since such a corner provides a region of abrasion against the treated work piece (here fabric 112) and it is desired to avoid severe scraping or tearing action upon a work piece.
The exposed, substantially radially oriented surface of each blade is desirably subtly serrated, as represented at S in FIG. 8, to impart a mild combing action upon the pile.
Electrifier with Contoured Rest
Referring to FIGS. 11-13, there is seen one embodiment of an electrifier apparatus 150 of the present invention which is provided with a contoured rest and a cross sectionally uniform (except for groove position) electrifier roll. The apparatus employs an electrifier roll or cylinder 151 rotatably mounted in suitable pillow blocks 152 and 153 carried by a frame 154 (not detailed). A conventional motor (not shown) drives a stub shaft 156 which is axially connected with the cylinder 151 by end plates (paired) 157 through V-belts 158 rotatably turning shieves 159 keyed to shaft 156. Operating speeds for the cylinder 151 can vary but normally fall in the range of from about 700 to 1400 rpm.
Cylinder 151 is suitably controllably heated internally similarly to cylinder 101.
Extending longitudinally in axially spaced relationship to cylinder 151 is a work support bar or rest 161 which is suitably supported by frame members (not detailed). Bar 161 is here comprised of a base support 161A over the head portion of which is mounted a cap plate 161B which is secured to support 161A by means of screws 161C. Work is illustratively being performed by the electrifier of this embodiment here on a longitudinally contour sheared high pile sliver knit fabric 161 which is continuously moved in the direction shown by arrow 163 over a nip region 165 between circumferential surface portions 170 of cylinder 151 and bar 161. The width of the web of fabric 162 can here likewise vary widely, but illustratively and commonly falls in the range of from about 48 to 84 inches, depending upon the type of knitting equipment being used. The fabric 162 can be considered for illustrative purposes here to be similar to fabric 112 above described.
As those skilled in the art will appreciate, the electrifier 150 can also be used to work upon many types of natural or synthetic fabrics, furs, and other webs of material, if desired.
The fabric 162 is advanced by a conventional work feeding mechanism (not detailed) through the electrifier 150 with its pile moving against the circumferential surface portions 170 of cylinder 151.
Preferably, the electrifier 150 is operated in cooperation with a control system, such as one provided by the present invention, so as to provide for automatically regulating transverse variations in web width, alignment, and registration of the fabric 112 with the cylinder 151 and its contours.
Cylinder 151 is commonly hollow, has a constant outside diameter, and has a longitudinal length which is variable and dependent upon such variables as the type of fabric being processed in any given instance, the capacity of the equipment, and the like. The outside diameter of the cylinder 151 can range typically from around 8 to 24 inches with about 12 inches being a particularly preferred and useful distance for peak diameters. The thickness of the wall of cylinder 151, if hollow can vary, but typically is in the range of from about 5/8 to 11/2 inches. The cylinder 151 is conveniently formable by casting a metal, such as steel, or the like, followed by machining operations to complete circumferential surface contours to desired specifications, the range of from about 5/8 to 11/2 inches. The cylinder 151 is conveniently formable by casting a metal, such as steel or the like followed by machining operations.
Formed in exterior circumferential surfaces of the cylinder 151 are helically arranged grooves 179 and 181. The direction of rotation of cylinder 151 is illustrated by arrow 169 which establishes the groove 179 as being right-hand groove in terms of the direction in which loose fibers, moisture, or the like will be laterally moved by the "combing" action of this groove upon the fabric 162 during operation of the electrifier 150. Similarly groove 161 is a left-hand groove since it "works" the surface of a treated fabric 112 toward the left.
The surface material of the cylinder is cut away to form the grooves 179 and 181 and the contour of a groove is illustrated, for example, in FIGS. 12 and 13. Groove characteristics here are similar to those for grooves 119 and 121.
In general, a larger diameter cylinder can have more grooves and therefore provide more polishing action per work station.
The surface portions of the cap plate 161B are formed so as to comprise a plurality of longitudinally spaced, circumferentially extending peaked ridged portions 167. Between adjacent pairs of peaks 167, the distance of the cap plate 161B progressively increases relative to the axis 168 of cylinder 151 to maximum distances as is illustrated, for example, in the regions 156 of the cap plate 161B. The configuration of the peaks 167 and the valleys 168 can, of course, vary from rest to rest depending upon such factors as the wishes of the user, the type of contour sheared fabric being worked, and the like.
A contour electrifier rest 161 is adaptable for use in a plane electrifier machine to process a three dimensional deep-pile contoured fabric wherein the effect achieved simulates a sewing together of small animal pelts, such as mink. The electrifier rest 161 has a contour surface in cap piece 161B made up of elements forming a mirror image of a contour in such a starting fabric for electification. The contour surface is formed so that the length of the travel path of contoured fabric drawn across its face is uniform. Tension applied to contoured fabric drawn across the various surfaces of rest 161 is therefore uniform and fabric distortion is substantially eliminated. Subsequently, as the contoured fabric is electrified it is provided with desired natural-looking contours. The contour surfaces are designed such that the fabric when passing over them traverses the same distance over all surfaces and is subjected to substantially the same amount of tension throughout to eliminate fabric distortion. The electrifier rest is preferably formed from a metal blank which is bent into a U-shape. In a particular embodiment, the apex of the bent blank is deformed to provide a first contour representing high points of the electrifier rest and the sides of the bent blank are deformed to protrude laterally in areas adjacent the low points of the apex contour. The deformation of the bent blank has the effect of providing fabric paths on the electrifier rest which are substantially of the same length over all regions thereof.
It will also be recognized that all the repetitive contours in an electrifier rest could be formed on a single continuous sheet, as shown in FIG. 17 of my aforementioned U.S. patent application. As the fabric is drawn across the rest it may be electrified precisely by cylinder action. See also FIG. 9 and the accompanying text of such application. In general, the web-path length in all regions of an electrifier rest is substantially equal in all regions of the electrifier rest regardless of its contour shape.
In contoured electrifier assemblies, the space between the periphery of the electrifier cylinder and the fabric rest is varied in a repeatable manner to conform substantially to variations in pile height of fabric to be processed therein. Because of less stringent mechanical restrictions, acheivement of variations in this space is not limited to geometric variations in the fabric rest as is the case with contour shears as described in my copending application above cited. Therefore, by the practice of the present invention, such variations in distance between cylinder circumferential portions and radially adjacent rest surface portions are achievable by either radially circumferentially contouring the electrifier cylinder or by incorporating into the electrifier rest surface contour profiles.
A contour electrifier of this invention includes web guide means for passing a web member between the rotatable heatable electrifier cylinder and the electrifier rest member such that such web member transversely is in predetermined registration with spacings radially existing between said cylinder and said rest member. Typically the web guide means includes web width control means.
Referring to FIGS. 14 through 17, various embodiments of systems are shown which each incorporate a modified control system of the present invention in combination with at least two contour processing units for controlling web travel along a path to, through and past each contour processing unit in the plurality of units incorporated into each respective system. Each processing unit may be either a contour shearing device or a contour electrifier device.
The structure of the control system utilized in each of the embodiments of FIGS. 14 through 17 involves a control system 31 in combination with a steering frame assembly 80. Thus, each control system is similar to the embodiment shown in FIG. 4 except that the web path is expanded and extended to permit location therealong of more than one contour processing unit.
In each of FIGS. 14 through 17, the processing units are either a contour shearing device or a contour electrifier device. Anyone skilled in the art will recognize that in place of contour shears or electrifiers, any other transverse operation may be employed. Each of the contour shearing devices is designated by the numeral 201 while each of the contour electrifier devices is designated by the numeral 202, for convenience. Similarly, in each of FIGS. 14 through 17, the pair of drive rollers incorporated into the control system is designated by the numbers 203 and 204 which are differentially driven with respect to one another in a manner similar to that above described in reference to the embodiment of FIGS. 1 and 3. In FIG. 15, roller 206 can alternately be used as a drive roll in place of 204.
In FIG. 17, arrangements of some processing units are illustrated which are so arranged relative to one another that the path of web travel from one such unit to the next thereof sequentially is generally flattened or straight. In the embodiments shown in FIGS. 14, 15 and 16, the respective processing units are arcuately arranged spatially relative to one another so that a series of bends or variations in web path occur with one path change occurring substantially at each such processing unit. Typically, the web path can be straight through an electrifier having a contoured cylinder and straight fabric rest. When a contoured rest is employed, however, the web must wrap or bend around the rest to some extent. As illustrated in FIG. 16, two or more successive such systems can be placed into a sequential arrangement relative to one another with respect to a path of web travel. | A control system is provided for maintaining a constant predetermined transverse width in a continuous elastic or extensible web while the web is traveling longitudinally and while simultaneously transversely aligning the longitudinally moving web in register with a transversely extending work station which transversely extends across the web path at a preset location. The invention further provides contoured electrifier apparatus which is adapted for use in the polishing of three dimensional deep pile surface contoured fabrics and the like. In addition, the invention provides ways of adapting the control system for use with a plurality of transversely extending processing units, each one of which can have transversely varying process conditions such as required in a contour shearing device or contoured electrifier. | 3 |
FIELD OF THE INVENTION
The present invention relates to a method for identifying microorganisms in culture bottles, after they have become positive. This identification can be accomplished in a brief time span, of, for example, one to three hours. As an example, the invention can be applied to identify bacteria in a specimen such as blood or urine, or to identify mycobacteria in specimen such as sputum or blood.
BACKGROUND OF THE INVENTION
Usually, the presence of biologically active agents, such as bacteria in a patient's blood, can be determined by the use of culture bottles. A typical quantity of 1 to 10 ml of blood is injected through a rubber septum which encloses the culture bottle, into the sterile culture bottle containing a culture medium. The vial is incubated at 37° C. and monitored for bacterial growth.
Known instrumental methods detect changes in the carbon dioxide content of the culture bottles, which is a metabolic by-product of bacterial growth. Recently, automated blood culture systems have been developed which involve disposing a chemical sensor inside the vial. These sensors respond to changes in the carbon dioxide concentration by changing their color or by changing their fluorescence intensity (see, e.g., Thorpe et al., "BacT/Alert: An Automated Colorimetric Microbial Detection System",. J. Clin. Microbiol., Jul. 1990, pp. 1608-12; U.S. Pat. No. 4,945,060; and Fraatz, R. et al. "Detection of Biological Activities in a Specimen by Measuring a Fluorescent Signal of a Substance to Indicate the Presence of Microorganisms,", EP 448923, Oct. 1991).
As a matter of experience, approximately 10% of all incubated blood culture bottles will exhibit bacterial growth. After detecting the presence of bacteria, it is important to identify the organisms. As an example, Staphylococcus aureus and Streptococcus pneumoniae, when found in a blood culture are usually representative of significant clinical disease. In contrast, non-S. aureus species of Staphylococcus, in particular S. epidermidis, although potentially of clinical importance, are usually found to be merely contaminants (Doern, G.V. et al., "Direct Identification of Staphylococcus aureus in Blood Culture Fluid with a Commercial Latex Agglutination Test", J. Clin. Microbiol., Dec. 1982, pp. 1048-1051). For this reason, early identification of S. epidermidis may prevent unnecessary antibiotic therapy, while the identification of bacteremias caused by S. aureus and St. pneumoniae require prompt and appropriate antibiotic therapy. They account for 50% of community-acquired bacteremias in AIDS patients, and rapid diagnosis can optimize therapy (Davis, T.E. et al., "Rapid, Direct Identification of Staphylococcus aureus and Streptococcus pneumoniae from Blood Cultures Using Commercial Immunologic Kits and Modified Conventional Tests", Diagn. Microbiol. Infect. Dis. 1992, No. 15, pp. 295-300).
All known methods that are used to identify bacteria from blood cultures require either removal of liquid from the culture bottle (McDonald, C.L. et al., "Rapid Identification of Staphylococcus aureus from Blood Culture Bottles by a Classic 2-Hour Tube Coagulase Test", J. Clin. Microbiol., Jan. 1995, pp. 50-52) or require removal and subsequent centrifugation of liquid (Rappaport, T. et al., "Evaluation of Several Commercial Biochemical and Immunologic Methods for Rapid Identification of Gram-Positive Cocci Directly from Blood Cultures", J. Clin. Microbiol., July 1988, pp. 1335-1338).
Handling of potentially infectious liquid from culture bottles by lab personnel represents an immense hazard. Therefore, extremely careful operation by lab personnel is required, which can be very time consuming and expensive. Consequently, there exists a need for an identification method that would not require removal of hazardous liquid from blood culture bottles or from tuberculosis test vials.
As discussed above, the concept of disposing a fluorescent chemical sensor material into each blood culture bottle has been previously disclosed. This technique allows for the ability to monitor not only the production of carbon dioxide, but also the consumption of oxygen by microorganisms over time. In this way, characteristic metabolic signatures are generated that could provide a means for organism identification.
However, there is a limitation to this technique in that carbon dioxide production and oxygen consumption are very general features that apply to many microorganisms species. Theoretically, the number of fluorescent chemical sensors within each blood culture bottle could be increased in order to monitor more features. However, this appears to be rather impractical because most fluorescent sensors work at optimum in almost identical spectral regions. Therefore, their signals would highly overlap.
Consequently, there still exists a need for an identification method that would not require removal of hazardous liquid from blood culture bottles or from tuberculosis test vials, and that monitors a larger number of microorganism-specific features.
SUMMARY OF THE INVENTION
It is an objective of the present invention to overcome the above problems of the prior art by providing a method for identifying microorganisms in culture bottles that does not require removal of liquid from culture bottles, and that monitors a larger number of microorganism-specific features than has previously been monitored in known methodologies.
According to the present invention, the above objective is achieved by repetitively extracting head space gas from "positive" culture bottles, by guiding the extracted gas to a large number of non-specific gas sensors, where each of the non-specific gas sensors is sensitive to a different group of chemical compounds that are in part emitted by the growth media and in part produced by the organisms, by combining the output signals of all non-specific sensors into one multi-dimensional vector, by analyzing the features of this vector over time during the repetitive gas extraction process, and comparing the resulting feature set with previously generated feature sets of known microorganisms in order to achieve identification of the microorganisms.
DESCRIPTION OF DRAWINGS
FIG. 1 depicts for a first microorganism the concentration, C, of a plurality of compounds in the head space gas of a positive culture bottle versus a parameter, N, that is different for each compound.
FIG. 2 depicts for a second microorganism the concentration, C, of a plurality of compounds in the head space gas of a positive culture bottle versus a parameter, N, that is different for each compound.
FIG. 3 shows the response curves, R1, R2, R3,...R10 of ten non-specific sensors versus a parameter, N, that is different for each compound.
FIG. 4 illustrates the output signals, S1, of all ten non-specific sensors in response to the first microorganism shown in FIG. 1. The ten output signals form a ten-dimensional vector, which is, for illustration purposes, shown as an area graph.
FIG. 5 illustrates the output signals S2, of all ten non-specific sensors in response to the second microorganism shown in FIG. 2. The ten output signals form a ten-dimensional vector, which is, for illustration purposes, shown as an area graph.
FIG. 6 shows a schematic view of a microorganism identification apparatus according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, head space gas is extracted from culture bottles that have registered positive for microorganisms on common manual or automated culture systems. Such bottles contain a standard amount of specimen such as blood and a growth medium, and contain a certain amount of head space gas. The bottles are sealed with a rubber septum, which not only allows for injection and extraction of liquid sample, but also for injection and extraction of head space gas.
In an apparatus according to the present invention, the extracted head space gas is guided to a large number of non-specific gas sensors. Each of the non-specific gas sensors is sensitive to a different group of chemical compounds that are in part emitted by the growth media and in part produced by the microorganisms. Common growth media contain a large number of ingredients such as soybean-casein, yeast, dextrose, sucrose, fructose, arginine, hemin, menadione, Vitamin B 6 and others. Therefore, the head space gas room is filled with a large number of volatile compounds.
If a culture bottle contains microorganisms, the microorganisms will consume volatile compounds in the liquid. As a result, the concentration of the volatile compounds in the head space will change over time, and the degree of change per compound will depend on the microorganism species. In addition, the microorganisms are producing new compounds that will end up in part in the head space gas. Again, the specific mixture of these new compounds will vary from one organism species to the next.
FIG. 1 depicts, for a first microorganism species, the concentration, C, of a plurality of compounds in the head space gas of a positive culture bottle versus a parameter, N, that is different for each compound. The quantity N could be, e.g., the molecule size of the volatile compounds. FIG. 2 depicts, for a second microorganism species, the concentration, C, of a plurality of compounds in the head space gas of a positive culture bottle versus N. The distribution C(N) is different for the two microorganism species, because every organism has its very specific metabolic activity pattern.
FIG. 3 shows the response curves, R1, R2, R3,...R10 of ten non-specific sensors versus the parameter N. Each sensor is responding to a whole group of compounds. The response curves are bell-shaped, and the location of the bells along the N axis varies from one sensor to the next.
By combining the distribution of compounds, C(N) in FIG. 1, with the response curves, R(N) in FIG. 3, one obtains an output signal, S1, for each of the ten sensor channels. The output signal of each channel is the result of the sensor's response to a whole group of components. How many components contribute to the output signal depends on the width of the bell-shaped response curve of the particular sensor. FIG. 4 depicts the ten channel signals that are obtained for the first microorganism. In general, these ten signals represent the components of a ten-dimensional vector. For the purpose of illustration, this vector is shown in FIG. 4 as an area graph.
If the same procedure is being applied to the distribution C(N) of the second microorganism species, shown in FIG. 2, the area graph of FIG. 5 is obtained. A comparison of FIGS. 4 and 5 indicates pronounced differences in the two graph profiles. In other words, the two ten-dimensional vectors have different feature sets. By analyzing the features of these vectors over time during a repetitive gas extraction process, and by comparing the resulting feature sets with previously generated feature sets of known microorganisms, an identification of unknown organisms can be achieved.
An apparatus according to the present invention is not limited to ten sensors (i.e. FIG. 3). In general, the identification capability will increase with the number of sensors. In a preferred embodiment, the number of sensors can be from 10 to 30sensors. An apparatus according the present invention does not need to detect compounds that are produced by the microorganisms. Even if no volatile compound would be produced by the microorganisms, the consumption of compounds that are present in the growth media would allow for microorganism identification. Growth media are produced under very controlled conditions to allow for optimum microorganism detection. Therefore, the concentration distribution of volatile compounds in the head space will be very repeatable. Due to organism metabolism, this distribution is changed. It is advantageous, however, that, in addition to their consumption, microorganisms are producing certain new compounds. This second effect results in an increased identification capability.
The procedure of generating multi-dimensional vectors, analyzing their features, and comparing the resulting feature sets with previously generated feature sets of known microorganisms can be accomplished by utilizing various available software programs known to anyone of ordinary skill in the art.
Furthermore, monitoring the consumption of volatile compounds that are emitted constantly by the growth media and/or monitoring the production of new volatile compounds produced by the microorganisms can be achieved by using many different types of non-specific gas sensors. Thus, for example, in a preferred embodiment, sensor arrays (i.e, an array of gas sensors) based on piezo-resonators can be utilized. In these sensor arrays, each element has a differently treated surface, so that different compounds adhere to different elements. Loading a surface with molecules of these compounds results in a change of the element's resonance frequency. The change in frequency is a measure of the amount of molecules that have settled on the surface, and the number of molecules is related to the density of those molecules within the head space gas.
The sensor area is currently under rapid development and it is very likely that new non-specific sensors will be developed in the future. It is intended that all such sensors are to be encompassed by the present invention.
FIG. 6 depicts schematically a microorganism identification apparatus in accordance with the present invention. The apparatus comprises a tray 2 inside a thermally insulated instrument housing 1. A number of positive culture bottles 3 which are sealed by means of a rubber-like septum 4 are arranged in a regular pattern on tray 2. A pair of two hollow stainless steel pencil-point needles 5 is connected to a sensor head 6 comprising a plurality of non-specific gas sensors. Sensor head 6 is mounted to a first vertical rail 7 and can be moved downward and upward on a block 8. If moved downward to a first position, needles 5 will penetrate septum 4. In this first position, head space gas is extracted from the culture bottle 3, through the needle(s) 5 and into sensor head 6, where the head space gas is analyzed for the concentration of volatile compounds therein. It is possible either to circulate the head space gas through one of the needles to the sensor head and then through the other needle back to the bottle, or to extract the head space gas, and refill the head space with a culture gas using an external gas tank.
Once a bottle has been analyzed, sensor head 6 is moved upward along rail 7 into a second position. Here, a set of heaters 10 is activated to sterilize the needles and to prevent cross-contamination between different bottles. After sterilizing the needles, block 8 is moved horizontally along a second rail 9 until the needles are in a position from where they can reach another bottle. Then, sensor head 6 is moved downward, and the same procedure is repeated.
Sensor head 6 is connected with a computer, where the data is stored and analyzed. As has been mentioned above, microorganism identification is achieved by comparing the resulting feature sets with previously generated feature sets of known microorganisms that are stored already within the computer.
It should be understood that FIG. 6 demonstrates one embodiment of the present invention. In other embodiments, the apparatus of the present invention can utilize a tray capable of containing at least one culture bottle, or up to ten culture bottles or up to one hundred culture bottles. In a further embodiment, the apparatus of the present invention can be utilized to identify microorganisms in up to two hundred fifty culture bottles on trays placed in this apparatus.
Therefore, the process of microorganism identification can be rapidly accomplished, i.e., within one to three hours. Furthermore, since no liquid is removed from the culture bottles in the present invention, the danger of infection to lab personnel is greatly reduced, making the present invention a very effective means for identification of microorganisms. | The present invention discloses a method for identifying microorganisms, directly in culture bottles, after they have become positive. The identification is accomplished within a time span of one to three hours. No liquid has to be removed from any of the culture bottles, which reduces the danger of accidents significantly. The invention can be applied to specimens such as for example, blood, urine or sputum. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fuel injection control system for use with an internal combustion engine and, more particularly, to a system for cutting off the supply of fuel to the engine during engine deceleration.
2. Description of the Prior Art
Electronic controlled fuel injection systems have already been proposed which include a fuel cut-off device for cutting off the supply of fuel to an internal combustion engine when the throttle valve is fully closed and the engine speed is above a predetemined reference value for fuel economy during engine deceleration.
With such conventional systems, however, any attempt to lower the reference engine speed value so as to provide a wider fuel cut-off range for higher fuel economy, would lead to a sudden engine speed drop at the start of fuel cut-off and a sudden output torque change resulting in a vehicle shock upon fuel supply resumption. This is due to a time lag between an engine speed detection and an actual engine output torque appearance.
In order to suppress any sudden engine speed drop as well as achieve higher fuel economy, improved systems have also been proposed which are adapted to cut off the supply of fuel to some of the cylinders when the engine speed is above a first predetermined value during engine deceleration and cut off the supply of fuel to the remaining cylinders when the engine speed is above a second predetermined value higher than the first predetermined value during engine deceleration. However, such conventional systems have been found unsatisfactory in that when a rapid engine deceleration occurs, for example, just after engine racing, a sudden large engine speed drop appears which would result in engine stalling.
The present invention provides means responsive to rapid engine deceleration for temporarily increasing the lower predetermined engine speed reference value to resume the supply of fuel to all of the cylinders of an engine at a higher engine speed.
SUMMARY OF THE INVENTION
The present invention provides a fuel injection control system for use with an internal combustion engine having fuel injection. The system comprises means for providing, in synchronism with engine rotation, a fuel injection pulse signal, corresponding to the rate of air flow to the engine, for operating the fuel injectors. A signal generator is provided for providing a first signal when the engine speed is above a first determined value and for providing a second signal when the engine speed is above a second predetermined value higher than the first predetermined value. The first signal is used to cut off the fuel injection pulse signal to a predetermined number of the fuel injectors during engine deceleration. The second signal is used to cut off the fuel injection pulse signal to the remaining fuel injectors during engine deceleration. Control means are provided which are responsive to rapid engine deceleration for increasing the first predetermined value.
The signal generator may comprise a first comparator for comparing a voltage corresponding to engine rotation period with a first reference voltage to provide the first signal when the former is lower than the first reference voltage, and a second comparator for comparing the engine rotation period indicative voltage with a second reference voltage lower than the first reference voltage to provide the second signal when the former is lower than the second reference voltage. The control means may comprise a differentiating circuit having its input coupled to the engine rotation period indicative voltage, and means increasingly conductive for reducing the first reference voltage as the output of the differentiating circuit increases. Alternatively, the control means may comprise a differentiating circuit having its input connected through an inverter to the output of the second comparator, and means increasingly conductive for reducing the first reference voltage as the output of the differentiating circuit increases.
In an alternative embodiment, the signal generator comprises first and second counters reset during each rotation of the engine. The first counter counts the number of occurrences of clock pulses of a constant pulse period. The signal generator also comprises a first pulse generator for providing a pulse to the second counter when the first counter indicates a first predetermined count, and a second pulse generator for providing a pulse to the second counter when the first counter indicates a second predetermined count larger than the first predetermined count. A third pulse generator is provided for providing a pulse to the second counter when the first counter indicates a third predetermined count larger than the second predetermined count. The second counter counts the number of pulses applied thereto. Switch means is provided for normally disconnecting the third pulse generator from the second counter. The switch means disconnects the second pulse generator from the second counter and instead connecting the third pulse generator to the second counter when the difference between an engine rotation period value measured during an engine rotation and another engine rotation period value measured during the previous engine rotation exceeds a predetermined value. The first signal is provided when the second counter indicates a 0 or 1 count and the second signal is provided when the second counter indicates a 0 count.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
The details as well as other features and advantages of this invention are set forth below and are shown in the accompanying drawings, in which:
FIG. 1 is a circuit diagram showing one embodiment of a fuel injection control system made in accordance with the present invention;
FIG. 2 is a circuit diagram showing a modified form of the fuel injection control system of FIG. 1;
FIG. 3 is a timing chart used in explaining the fuel injection control system of FIG. 2; and
FIG. 4 is a circuit diagram showing a significant portion of an alternative embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a fuel injection control system, embodying the present invention, is shown as incorporated in an internal combustion engine having individual fuel injectors 1 to 4 for each of the cylinders of the engine. The fuel injectors 1 to 4 are divided into two groups. The first group of fuel injectors 1 and 2 are commonly connected to ground through the collector-emitter circuit of a first switching transistor 12. The second group of fuel injectors 3 and 4 are grounded commonly through the collector-emitter circuit of a second switching transistor 14. The bases of the first and second transistors 12 and 14 are coupled to a fuel injection pulse signal A corresponding to the rate of air flow to the engine. The fuel injection pulse signal A is generated in synchronism with engine crankshaft rotation from a conventional control unit (not shown). When the fuel injection pulse signal A goes high, the first and second transistors 12 and 14 become conductive to open the first and second groups of fuel injectors, respectively, for a period of time corresponding to the rate of air flow to the engine.
The base of the first transistor 12 is grounded through the collector-emitter circuit of a third switching transistor 16, the base of which is connected to the output of a first AND circuit 18. The base of the second transistor 14 is connected to ground through the collector-emitter circuit of a fourth switching transistor 20 with its base connected to the output of a second AND circuit 22. Each of the first and second AND circuits 18 and 22 has an input B from a throttle switch (not shown) which provides a high output when the throttle valve is in its fully closed position. In this embodiment, engine deceleration is inferred from the high output of the throttle switch. The first and second AND circuits 18 and 22 have a function to render the third and fourth transistors 16 and 20 conductive so as to cut off the fuel injection pulse signal A to the first and second transistors 12 and 14, respectively, when the throttle valve is fully closed; that is, during engine deceleration. The first AND circuit 18 has an additional input connected to the output of a first comparator 24. Also, the second AND circuit 22 has an additional input connected to the output of a second comparator 26.
The first comparator 24 has an inverting input connected to a signal C increasing as the engine speed decreases. The non-inverting input of the first comparator 24 is connected to a reference voltage V 1 determined by the ratio of the values of resistors 28 and 30 and also to ground through the collector-emitter circuit of a transistor 32. The base of the transistor 32 is connected through a differentiating circuit 34 to the engine speed indicative signal C. The first comparator 24 compares the engine speed indicative signal C with the reference voltage V 1 and produces a low output when the former is higher than the latter. That is, the output of the first comparator 24 is at its low level when the engine speed is lower than a first predetermined engine speed value represented by the reference voltage V 1 . The differentiating circuit 34 differentiates the engine speed indicative signal C and provides an output representing the rate of decrease of the engine speed. As the output of the differentiating circuit 34 increases, the transistor 32 conducts increasingly to lower the reference voltage V 1 . That is, the first predetermined engine speed value increases as the engine speed decreasing rate increases.
The second comparator 26 has an inverting input coupled to the engine speed indicative signal C and a noninverting input coupled to a reference voltage V 2 determined by the ratio of the values of resistors 36 and 38. The second comparator 26 compares the engine speed indicative signal C with the reference voltage V 2 and produces a low output when the former is higher than the latter. That is, the output of the second comparator 26 is at its low level when the engine speed is lower than a second predetermined engine speed value represented by the reference voltage V 2 . The resistors 28, 30, 36 and 38 are suitably selected such that the reference voltage V 1 is higher than the reference voltage V 2 .
The operation of the fuel injection control system of the present invention will now be described. Assuming first that the engine is gently decelerated but the engine speed is above the second predetermined engine speed value represented by the reference voltage V 2 determined by the resistors 36 and 38, all of the outputs of the throttle switch, and the first and second comparators 24 and 26 are high. Consequently, the first and second AND circuits 18 and 22 provides high output to the third and fourth switching transistors 16 and 20 which thereby become conductive to cut off the flow of the fuel injection pulse signal A to the first and second transistors 12 and 14, respectively. This renders the first and second groups of fuel injectors 1 to 4 inoperative to shut off the supply of fuel to the respective cylinders.
When the engine speed falls below the second predetermined value but above the first predetermined value, the output of the second comparator 26 goes low to change the output of the second AND circuit 22 to its low level. This renders the fourth transistor 20 non-conductive to permit application of the fuel injection pulse signal A to the second transistor 14. As a result, the second group of fuel injectors 3 and 4 become operative to resume the supply of fuel to the associated cylinders.
When the engine speed further falls below the first predetermined engine speed value represented by the reference voltage V 1 , the output of the first comparator 24 goes low to change the output of the first AND circuit 18 to its low level. This renders the third transistor 16 non-conductive to permit application of the fuel injection pulse signal A to the first transistor 12. As a result, the first group of fuel injectors 1 and 2 becomes operative to resume the supply of fuel to the associated cylinders. In this state of the circuit, fuel is supplied through all of the fuel injectors 1 to 4 to the respective cylinders.
If rapid engine deceleration occurs, the output of the differentiating circuit 34 increases to increasingly conduct the transistor 32 so as to decrease the reference voltage V 1 , whereby the first comparator 24 can provide a low output before the engine speed falls below the first predetermined engine speed value. As a result, the supply of fuel to all of the cylinders can be resumed at an engine speed higher than that predetermined for no rapid engine deceleration. This is effective to suppress engine speed drop resulting from rapid engine deceleration found just after engine racing.
Referring to FIG. 2 a modified form of the fuel injection control system of FIG. 1 is shown. The structure in FIG. 2 is generally the same as shown in FIG. 1 except that the differentiating circuit 34 has its input not connected directly to the engine speed indicative signal C but connected through an inverter 40 to the output of the second comparator 26. Accordingly, like parts are designated by like reference numerals. This modification decreases the reference voltage V 1 a predetermined value for a period of time determined by the time constant of the differentiating circuit 34 after the engine speed falls to the second predetermined engine speed value to change the output of the second comparator 26 from its high level to its low level.
With particular reference now to FIG. 3, there are shown two voltage-versus-time waveforms for the reference voltages V 1 and V 2 in connection with the number of cylinders to which fuel is supplied.
It is assumed that the engine is decelerated rapidly as shown by the solid curve D 1 of FIG. 3. When the engine speed decreases to the second predetermined value represented by the reference voltage V 2 at a time t 1 , the output of the second comparator 26 changes to its low level, causing fuel supply resumption for the cylinders associated with the second group of fuel injectors 3 and 4. The low output of the second comparator 26 is applied to the inverter 40 which thereby provides a high signal to the differentiating circuit 34. Consequently, the differentiating circuit 34 increasingly conducts the transistor 32 to lower the reference voltage V 1 for a period of time t 3 -t 1 determined by the time constant of the differentiating circuit 34. During rapid engine deceleration, the engine speed indicative signal C increases to the reduced reference voltage or the engine speed decreased to the increased first predetermined value at a time t 2 to change the output of the first comparator 24 to its low level, causing fuel supply resumption for the cylinders associated with the first group of fuel injectors 1 and 2.
Assuming then that the engine is decelerated gently as shown by the broken curve D 2 of FIG. 3, the output of the second comparator 26 changes to its low level, causing fuel supply resumption for the cylinders associated with the second group of fuel injectors 3 and 4 when the engine speed falls to the second predetermined value represented by the reference voltage V 2 at a time t 1 .
During gentle engine deceleration, the engine speed indicative signal C does not increase to the reduced reference voltage for the time period t 3 -t 1 determined by the time constant of the differentiating circuit 34. Consequently, the output of the first comparator 24 is held high to continuously cut off the supply of fuel through the first group of fuel injectors 1 and 2 to the associated cylinders until the engine speed indicative signal C increases to the reference voltage V 1 at a time t 4 .
It is to be noted that the input of the inverter 40 may be connected to the output of an additional comparator which compares the engine speed indicative signal C with a reference voltage set between the reference voltages V 1 and V 2 if it is desired, because of drivability and other considerations, to set a large difference between the reference voltages V 1 and V 2 .
Referring to FIG. 4, there is illustrated a second embodiment of the present invention which includes a presettable up-counter 44 having a capacity to count from 0 to 255, a presettable down-counter 46 having a capacity to count from 0 to 255 and latch the final count, and an encoder 50. In FIG. 4, the letter E indicates crankshaft position electric pulses each produced at a predetermined number of degrees of rotation of the crankshaft, and the letter F clock pulses having a 1 m.sec pulse period.
The crankshaft position pulse E is applied to the up-counter 44 which thereby is reset to a value (in this embodiment 5) preset for determination of rapid engine deceleration and increments from the preset value one each time a clock pulse F is applied thereto until the next crankshaft position pulse E is applied thereto. The count made between the two crankshaft position pulses E corresponds to 4 plus the quotient of the engine rotation period divided by 1 m.sec.
The crankshaft position pulse E is applied also to the down-counter 46 which thereby is reset to a value corresponding to the final count on the up-counter 44; i.e., the previous engine rotation period G plus 4 and increments one from the preset value each time a clock pulse F is applied thereto. If the present engine rotation period G' is larger than the preset value G+4, the down-counter 46 decrements back from 255. The 128 output terminal of the down-counter 46 is at a high level when the present engine rotation period G' is larger than the previous engine rotation period G plus 4, and at a low level when the former is equal to or smaller than the latter. Accordingly, it will be understood that the state of the 128 output terminal of the down-counter 46 can be used for determination of a rapid engine rotation period drop or rapid engine speed drop.
The 2, 4, 16 and 32 output terminals of the up-counter 44 are connected directly to respective inputs of a third AND circuit 52, the other input of which is connected through an inverter 54 to the 8 output terminal of the up-counter 44. The third AND circuit 52 provides a high output when the count on the counter 44 reaches 54; that is, when the engine rotation period reaches 50 m.sec. The output of the third AND circuit 52 is connected to one input of an OR circuit 60. The 2, 8, 16 and 32 output terminals of the counter 44 are connected directly to respective inputs of a fourth AND circuit 56, the other input of which is connected through an inverter 58 to the 4 output terminal of the counter 44. The fourth AND circuit 56 provides a high output when the count on the counter 44 reaches 58; that is, when the engine rotation period reaches 54 m.sec. The output of the fourth AND circuit 56 is connected through a first electronic switch 62 to the other input of the OR circuit 60. In addition, the 64 output terminal of the counter 44 is connected through a second electronic switch 64 to the other input of the OR circuit 60. The first electronic switch 62 has a control input connected to the 128 output terminal of the down-counter 46. The second electronic switch 64 has a control input connected through an inverter 66 to the 128 output terminal of the down-counter 46. The first and second electronic switches 62 and 64 close in response to a high input.
The output of the OR circuit 60 is connected to an up-counter 68 having a capacity to count from 0 to 3 and latch the count. The crankshaft position pulse E is applied to the up-counter 68 which thereby is reset to zero and increments one each time a positive going pulse is applied thereto from the OR circuit 60. The up-counter 68 latches and outputs the count made just before the application of the crankshaft position pulse E. The output of the up-counter 68 is 0 when the engine rotation period is below 50 m.sec, 1 when the engine rotation period is 50 m.sec or more but below 54 m.sec during rapid engine deceleration or when the engine rotation period is 50 m.sec or more but below 60 m.sec during gentle engine deceleration, and 2 when the engine rotation period is 54 m.sec or more during rapid engine deceleration or when the engine rotation period is 60 m.sec or more during gentle engine deceleration.
The 2 output terminal of the up-counter 68 is connected through an inverter 70 to one input of the first AND circuit 18, the other input of which is connected to the throttle position indicative signal B. The inverter 70 provides a high output to the first AND circuit 18 when the output of the counter 68 is 0 or 1. The 2 output terminal of the counter 68 is also connected to one input of a NOR circuit 72, the other input of which is connected to the 1 output terminal of the counter 68. The output of the NOR circuit 72 is connected to one input of the second AND circuit 22 having the other input coupled to the throttle position indicative signal B. The NOR circuit 72 provides a high output to the second AND circuit 22 when the output of the counter 68 is 0.
The operation is as follows: Assuming first that the engine is gently decelerated, the throttle switch provides a high output and the difference between the values G and G' is 4 or less to cause the dwon-counter 46 to provide at its 128 output terminal a low output which opens the first switch 62 and closes the second switch 64.
When the engine rotation period is below a first predetermined value of 50 m.sec, the count on the up-counter 44 cannot reach 54 and thus the output of the third AND circuit 52 is held at a low level. Consequently, the up-counter 68 receives no pulse and indicates a zero count. As a result, the inverter 70 provides a high output to the first AND circuit 18 which thereby cuts off the supply of the fuel injection pulse signal to the first group of fuel injectors 1 and 2. In addition, the NOR circuit 72 provides a high output to the second AND circuit 22 so as to cut off the supply of the fuel injection pulse signal to the second group of fuel injectors 3 and 4.
When the engine speed decreases to increase the engine rotation period above 50 m.sec but below a second predetermined value of 60 m.sec, the output of the third AND circuit 52 changes to its high level to provide a pulse to the up-counter 68 when the up-counter 44 indicates a 54 count. This changes the output of the up-counter 44 to 1. As a result, the output of the NOR circuit 72 is changed to its low level which is applied to the second AND circuit 22 to permit application of the fuel injection pulse signal to the second group of fuel injectors 3 and 4 so as to resume the supply of fuel through them to the associated cylinders. The output of the inverter 70 is held high to continuously cut off the supply of the fuel injection pulse signal to the first group of fuel injectors 1 and 2.
When the engine speed further decreases to increase the engine rotation period above 60 m.sec, the output of the third AND circuit 52 changes to its high level to provide a pulse to the up-counter 68 when the up-counter 44 indicates a 54 count and the 64 output of the up-counter 44 changes to a high level to provide a pulse through the second switch 64 to the up-counter 68 when the up-counter 44 indicates a 64 count. This changes the output of the up-counter 44 to 2. As a result, the output of the inverter 70 is changed to its low level which is applied to the first AND circuit 18 to permit application of the fuel injection pulse signal to the first group of fuel injectors 1 and 2 so as to resume the supply of fuel through them to the associated cylinders. The output of the NOR circuit 72 is held low to continuously permit the application of the fuel injection pulse signal to the second group of fuel injectors 3 and 4. Since the first switch 62 is open, the state of the circuit cannot be changed when the engine rotation period reaches 60 m.sec.
If the engine is rapidly decelerated, the difference between the values G and G' becomes larger than 4 and the 128 output of the down-counter 46 changes to is high level so as to close the first switch 62 and open the second switch 64.
When the engine rotation period is below 50 m.sec, the count on the up-counter 44 cannot reach 54 and thus the output of the third AND circuit 52 is held at a low level. Consequently, the up-counter 68 receives no pulse and indicates a zero count. As a result, the inverter 70 provides a high output to the first AND circuit 18 which thereby cuts off the supply of the fuel injection pulse signal to the first group of fuel injectors 1 and 2. The NOR circuit 72 provides a high output to the second AND circuit 22 so as to cut off the supply of the fuel injection pulse signal to the second group of fuel injectors 3 and 4.
When the engine speed decreases to increase the engine rotation period above 50 m.sec but below 54 m.sec, the output of the third AND circuit 52 changes to its high level to provide a pulse to the up-counter 68 when the up-counter 44 indicates a 54 count. This changes the output of the up-counter 44 to 1. As a result, the output of the NOR circuit 72 is changed to its low level which is applied to the second AND circuit 22 to permit application of the fuel injection pulse signal to the second group of fuel injectors 3 and 4 so as to resume the supply of fuel through them to the associated cylinders. The output of the inverter 70 is held high to continuously cut off the supply of the fuel injection pulse signal to the first group of fuel injectors 1 and 2.
When the engine speed further decreases to increase the engine rotation period above 54 m.sec, the output of the third AND circuit 52 changes to its high level to provide a pulse to the up-counter 68 when the up-counter 44 indicates a 54 count and the output of the fourth AND circuit 56 changes to a high level to provide a pulse through the first switch 62 to the up-counter 68 when the up-counter 44 indicates a 58 count. This changes the output of the up-counter 44 to 2. As a result, the output of the inverter 70 is changed to its low level which is applied to the first AND circuit 18 to permit application of the fuel injection pulse signal to the first group of fuel injectors 1 and 2 so as to resume the supply of fuel through them to the associated cylinders. The output of the NOR circuit 72 is held low to continuously permit the application of the fuel injection pulse signal to the second group of the fuel injectors 3 and 4. Since the second switch 64 is open, the state of the circuit cannot be changed when the engine rotation period reaches 60 m.sec; that is, when the count on the up-counter 44 reaches 64. It is to be noted that the second predetermined engine rotation period value decreased from 60 m.sec. to 54 m.sec during rapid engine deceleration.
While the present 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 alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
These embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | A fuel injection control system is disclosed for an internal combustion engine having fuel injectors. The system comprises fuel cut-off means operable for rendering some of the fuel injectors inoperative only when the engine speed exceeds a first predetermined value during engine deceleration and for rendering the remaining fuel injectors inoperative only when the engine speed exceeds a second predetermined value higher than the first predetermined value during engine deceleration. Control means is provided for increasing the second predetermined value when rapid engine deceleration occurs. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/591,761, “A Control Layer Algorithm for Ad hoc Networks in Support of Urban Search and Rescue (USAR) Applications”, filed Jul. 28, 2004.
BACKGROUND OF INVENTION
[0002] The world has witnessed a tremendous growth in the deployment of wireless network technology driven by the need for ubiquitous service and rapid developments in telecommunications infrastructure. Mobile hosts such as notebook computers, featuring powerful CPUs and gigabytes of disk space are now easily affordable and becoming quite common in everyday life. At the same time, huge improvements have been made in wireless network hardware, and efforts are being made to integrate the two into a meaningful resource such as the Internet. We are witness to large scale proliferation of mobile computing and wireless technology in our day-to-day lives in the form of various hardware interfaces and technology devices, running numerous applications catering specifically to wireless technology. The use of cell phones and PDA's for mobile video conferencing, GPS based tracking systems and remote wireless sensor surveillance gives us an indication of the growth and proliferation of wireless technology in today's world.
[0003] The increased demand and usage of mobile devices, directly correlates to the inflated demand for mobile data and Internet services. The number of subscribers to wireless data services is predicted to reach 1.3 billion by end of 2004, and the number of wireless messages is sent per month is predicted to reach 244 billion by December 2004. But these devices and technology use the standard wireless network model of a base station, repeaters, access points, and wireless nodes. Oftentimes however mobile users will want to communicate in situations in which no fixed wired infrastructure is available, because it may not be possible to provide the necessary infrastructure or because the expediency of the situation does not permit this installation. The term, “ad hoc network” refers to such a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration.
[0004] The history of ad hoc networks dates back to the DARPA radio packet network in 1972, which was primarily inspired by the efficiency of the packet switching technology, such as bandwidth sharing and store and forward routing, and its possible application in mobile wireless environment. But, it was not until the early 90's when research in the area of ad hoc networks gained significant momentum and widespread attention. This could be attributed to the surge in cheap availability of network hardware, the micro computer revolution, and the increasing number of applications that required an ad hoc network kind of setup. Some of the common applications for ad hoc networks include: conference halls, classrooms, search and rescue operations, vehicular communication, wireless surveillance and military operations. In an ad hoc network, every node acts as a router, and forwards packets towards the destination. It is a self-organized network where every node cooperates to provide connectivity and services.
[0005] MANET's or Mobile Ad hoc Networks have gained significant momentum as they are the solution for providing network services to mobile users at places where there is no infrastructure or an existing infrastructure needs wireless extensions. Wireless Mobile Ad Hoc Networks (MANETs) are very well suited to substitute current 802.11 Wireless Local Area Networks in practical implementations of semi-autonomous ground robots in Urban Search and Rescue (USAR) operations. MANETs are infrastructureless, self-configurable and self-forming networks with multi-hop capabilities, all very important features for USAR applications. However, node mobility may still cause partitions in the network topology, isolating robots from the network or even losing them, hindering the mission's success.
[0006] Urban Search and Rescue (USAR) focuses on locating life and resources in collapsed buildings or disaster sites affected by artificial or natural calamities. These disaster sites pose several situational hazards that drastically affect the efficiency of human rescue teams. Disaster sites are inherently unsafe, and movement inside these sites is extremely restricted due to the availability of only small or no entry voids to explore the rubble. Vibrations might further affect the foundation of the collapsed construction and could trigger a secondary collapse. Disaster sites are usually contaminated by water/sewage distribution systems, toxic gas spills, body fluids and other hazardous materials and gases. All of the above mentioned factors make it imperative to look for other effective means to carry out rescue operations. The use of mobile robots provides an effective alternative for improved efficiency in USAR operations. Due to smaller sizes and robust design, robots can explore disaster sites that pose numerous hazard threats and are not conducive for exploration by relief workers.
[0007] In USAR operations, and in general, in Safety, Security and Rescue (SSR) operations, a group of semi-autonomous ground vehicles is sent out to perform a determined mission under the guidance of the main controller, such as surveying a disaster site for life and resources. The success of the mission highly depends on the quality of the communication among the robots and the robots and the main controller. If communication is lost, the robots will lose contact with the main controller and the mission will likely fail. On the other hand, effective communication could actually enhance and increase the mission's success if it provided for a wider range of coverage, supported coordinated rescue operations and tele-operation, and guaranteed permanent connectivity despite network conditions and signal propagation effects. Communication among mobile robots and the main controller is currently known in the prior art to be achieved by using wireless local area networks (WLANs) based on the IEEE 802.11 standard.
[0008] The idea of using a WLAN of mobile robots in USAR operations has several drawbacks. First, WLANs require networking (access point) and energy (power outlet for access point) infrastructures, which are not readily available at disaster sites. Second, WLANs must be set up and configured, taking away precious search and rescue time. Third, communication performance is heavily affected by interferences, signal propagation effects, and the distance of the mobile nodes from the access point. 802.11 WLANs have an automatic fallback mechanism that reduces the transmission rate according to the quality of the transmission media. This feature makes the exploration of distant areas from the access point really difficult and risky. Finally, WLANs can't guarantee permanent connectivity. In USAR operations, mobile robots maneuvering the disaster site would need to maintain constant communication with a stationary controller, transmitting search findings and location information. The main controller is usually stationary and provides scope for tele-operation and analyzes findings of the robots to provide meaningful information to the relief workers. To ensure this constant communication with the main controller, the mobile robots and the main controller need to stay within the transmission range of the access point. Nodes moving beyond the transmission range of the access point are considered lost unless they use inherent position awareness protocols to trace route back to the main controller or work on an autonomous manner. Loss of robots not only produces financial loss but also jeopardize the mission's final success.
[0009] Most of the above mentioned issues could be resolved by forming a wireless mobile ad hoc network (MANET) of robots, where every node cooperates to provide connectivity and services. MANETs are self-organized and self-configured networks with multi-hop routing capabilities that operate without the need of any fixed infrastructure. Therefore, MANETs can be deployed and used rapidly, can drastically increase the area of coverage compared to WLANs, and can maintain communication with the main controller at all times in an easier manner, either by direct links or through intermediate nodes. MANETs may also reduce network congestion as routing remains distributed and the use of multi-hop routing may provide alternate routes for communication with the main controller.
[0010] Associated with these advantages and application possibilities are some inherent drawbacks that hold MANETs from being used as the communication platform of choice for semi-autonomous robots in USAR applications. For example, the nodes in an ad hoc network can move arbitrarily in a random direction and speed, which results in a very dynamic topology with frequent link breakages, disrupting communication among nodes and the main controller. Signal propagation effects in those harsh environments also cause communication problems. Nodes operating in ad hoc networks usually rely on batteries for energy, thus for these nodes energy-efficient protocols become a critical design criterion. Also, bandwidth utilization is another significant factor of concern, thus necessitating reduced routing overhead and good congestion control mechanisms.
[0011] By providing a constant communication link between the mobile robots and the main controller, it is ensured that the robots do not get lost. The term “node connectivity” is introduced here to denote the same. Node connectivity is defined as the ability of a node to continue or stop its mobility without breaking away from the network of nodes, while remaining in constant communication with the main controller. Forming an ad hoc network of the mobile robots and the main controller effectively addresses the issue of maximized area of coverage. By forming an ad hoc network, intermediate nodes act as a router forwarding packets towards the destination. By this method, robots continue their mobility beyond the transmission range of the main controller if an intermediate node exists through which it can establish a connection with the main controller. However, forming an ad hoc network of mobile robots does not address the issue of node connectivity. It is essential to ensure node connectivity in applications where loss of a node mobile robot in the case of urban and search and rescue operations could be detrimental to the performance of the system.
[0012] The vast majority of the research work done in the area of ad hoc networks has been focused on designing and developing routing protocols to address the issues of node mobility, overhead and energy efficiency. There has been an increased attention in developing routing protocols that consider the issue of link stability and the design of link stability based routing protocols, where routes to the destination are selected based on the strength of signals received from neighboring nodes or the duration for which the link has been active. It is well-known that there is no unique routing protocol that satisfies the requirements of all types of applications and rather, routing protocols are designed to optimize the performance of the application under consideration. For example, while an ad hoc network of laptops in a classroom presents low or no mobility and infrequent topology changes, the topology of an ad hoc network of nodes with random mobility in a military environment is highly dynamic. Similarly, the requirements for an ad hoc network of robots operating in urban search and rescue environments is different as robots have low but random mobility and work in unfriendly environments for signal propagation. The idea of applying ad hoc networking to a team of mobile robots is known in the art. The protocols known in the art include, Topology Broadcast based on Reverse-Path Forwarding (TBRPF), Ad hoc On-Demand Distance Vector (AODV), Associativity Based Routing (ABR), Temporally Ordered Routing Algorithm (TORA) and Zone Routing Protocol (ZRP). However, none of the prior art solutions are capable of guarantying node connectivity considering the energy available in the robots and the signal strength, a quite important characteristic for USAR applications where the final goal is to extend the area of coverage, avoid network partitions and loss of robots, and also extend the length of the mission under harsh signal propagation environments.
[0013] As illustrated in FIG. 1 , a stationary main controller, and 6 mobile nodes (robots) are connected to form an ad hoc network. Robots 1 , 2 , 3 and 4 are within the transmission range of the main controller (denoted by a circle), while robots 5 and 6 are outside its transmission range. This doesn't necessarily mean that robots 5 and 6 have lost their communication with main controller. For example, robot 6 can still communicate with the main controller through robot 2 . Here robot 2 acts as a router, transmitting packets to and from robot 6 . Similarly robot 5 can transmit its packets to the main controller through robot 3 or 4 . But as it can be seen, robot 2 is moving outside the transmission range of the main controller. This not only breaks the communication link between robot 2 and the main controller, but also the link between robot 6 and the main controller, as robot 2 was serving as the link between these two nodes. None of the existing routing protocols current known in the art address this issue as illustrated and described with reference to FIG. 1 . None of the prior art routing protocols is able to ensure that in addition to the existing demands of ad hoc networks such as node mobility, link stability, energy efficiency and reduced routing overhead, that the requirement for node connectivity is satisfied.
[0014] Accordingly, what is needed in the art is a system and method that is effective in assuring node connectivity in an ad hoc network.
[0015] However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified need could be fulfilled.
SUMMARY OF INVENTION
[0016] In accordance with the present invention is provided a system and method effective in establishing a control layer algorithm that finds and maintains stable links among the mobile nodes and the main controller of an ad hoc network considering the energy of the nodes and the quality of the signal, thereby assuring node connectivity within the ad hoc network. In accordance with the present invention, the term “node connectivity” is defined as the ability of a node to continue or stop its mobility without breaking away from the network of nodes, while remaining in constant communication with the main controller.
[0017] The system and method in accordance with the present invention are implemented in a control layer that operates between the network and data link layers to provide for node connectivity. This modularity provides the flexibility of selecting the routing and link layer protocols that best suit the current application. In a particular embodiment, the control layer in accordance with the present invention is implemented on top of a MAC layer of the IEEE 802.11 type and below the Ad Hoc On-Demand Distance Vector (AODV) routing protocol.
[0018] In a particular embodiment in the field of mobile search and rescue, the present invention provides for synergy between communications and control by implementing a control layer algorithm that considers the energy level in mobile nodes and the quality of the received signals to control the mobility of the robots and guarantee continuous node connectivity, avoiding loss of robots and network partitions. Accordingly, the present invention guarantees node connectivity, increases the area of coverage and the throughput in the network with minimum extra overhead under different mobility patterns.
[0019] In accordance with the present invention is provided, a method to assure node connectivity in an ad hoc wireless network comprising a wireless main controller, a plurality of wireless nodes having a plurality of neighboring nodes and a plurality of wireless links connecting the wireless main controller, the plurality of wireless nodes and the plurality of neighboring nodes. The proposed method includes, computing a composite threshold for each of a plurality of neighboring nodes of a plurality of nodes, assigning a mobility to each of the plurality of nodes based on the composite threshold for each of the plurality of neighboring node and using the mobility assigned to each of the plurality of nodes to assure node connectivity in the ad hoc network.
[0020] The composite threshold in accordance with the present invention is computed for each of the plurality of neighboring nodes for a particular node by transmitting a hello signal from each of the plurality of nodes, the hello signal comprising an energy level and a signal power level, receiving a plurality of transmitted hello signals at each of the plurality of nodes, the plurality of transmitted hello signals received from each of the plurality of neighboring nodes, identifying the signal power level and the energy level for each of the plurality of transmitted hello signals received from each of the plurality of neighboring nodes, accessing an information table stored at each of the plurality of nodes and computing a composite threshold for each of the neighboring nodes based on the information table. As such, the composite threshold is a measure of the quality and stability of a wireless connection between a node and each of the neighboring nodes.
[0021] The information table in accordance with the present invention includes an entry for each of the plurality of neighboring nodes, a corresponding entry for the normalized energy level for each of the plurality of neighboring nodes and a corresponding entry for the normalized signal power level at which the hello packet was received from each of the neighboring nodes.
[0022] In computing a composite threshold for each of the neighboring nodes a weighting factor, ALPHA is used. ALPHA is determined by identifying the normalized energy level for each of the plurality of neighboring nodes, identifying the normalized signal power level for the hello signal received from each of the neighboring nodes and calculating the composite threshold for each of the neighboring nodes based on the following relationship:
composite threshold=(weighting factor*normalized energy level)+(1−weighting factor)*normalized signal power level)
[0023] The normalized energy level is equal to a ratio of the energy level of each of the plurality of neighboring nodes to a predetermined maximum possible energy level for the node and the normalized signal power level is equal to a ratio of the signal power level of each of the plurality of neighboring nodes to a predetermined maximum possible signal power level for the node. In particular, the predetermined maximum possible energy level for the node is equal to the energy value of a node battery when fully charged and the predetermined maximum possible signal power level for the node is equal to the signal power level between two nodes in close proximity and assuming ideal transmission conditions.
[0024] The weighting factor may be a dynamic weighting factor based on current network behavior or a static weighting factor.
[0025] Once the composite threshold values for each of the neighboring nodes have been determined, they are stored in update table at each of the plurality of nodes and the update table is transmitted to the main controller. As such, the update table contains an entry for each of the plurality of neighboring nodes and a corresponding entry for the composite threshold for each of the plurality of neighboring nodes.
[0026] In a particular embodiment, the method and system to assure node connectivity in accordance with the present invention are adapted to be implemented at a control layer, thereby operating between a routing layer and a data link layer. The routing layer may be selected from any number of routing protocols known in the art. In a particular embodiment, the routing layer selected is AODV protocol. Additionally, the data link layer may be selected from any number of data link layers known in the art and in a particular embodiment, the IEEE 802.11b MAC protocol is selected.
[0027] Assigning a mobility to each of the plurality of nodes is based on the composite threshold for each of the plurality of neighboring nodes and further includes the steps of, evaluating the composite threshold for each of the plurality of neighboring nodes received from each of the plurality of nodes to determine if each of the plurality of nodes has a link connection to the main control and assigning a mobility to stop the movement of the node if the node if is determined to not have a link connection to the main controller. The link connection between the node and the main controller may be a direct connection or a connection through a safe neighbor, such that the link connection is above the composite threshold for the node.
[0028] After the mobility of the node has been stopped, the mobility may be assigned to restart the movement of the node if the node is determined to have reestablished a link connection to the main controller or the a request may be made to move the node closer to the main controller.
[0029] In a particular embodiment of the present invention, a computer readable medium for providing instructions for directing a processor to carry out a method to assure node connectivity in an ad hoc wireless network comprising a wireless main controller, a plurality of wireless nodes having a plurality of neighboring nodes and a plurality of wireless links connecting the wireless main controller, the plurality of wireless nodes and the plurality of neighboring nodes is provided. The instructions including steps for computing a composite threshold for each of a plurality of neighboring nodes and transmitting the composite threshold for each of a plurality of neighboring nodes and means for assigning a mobility to each of the plurality of nodes based on the composite threshold for each of the plurality of neighboring nodes and transmitting the assigned mobility to each of the plurality of nodes to assure node connectivity in the ad hoc network.
[0030] As such, the present invention provides for the maintenance of a constant link between the mobile nodes and the main controller. The prevent invention provides additional benefits over the systems and methods currently known in the art.
[0031] The present invention provides for a minimal increase in routing overhead thereby reducing congestion in the network conserving the battery power of the nodes.
[0032] The present invention does not confine and restrict the area of coverage for providing node connectivity.
[0033] The present invention considers the energy of each of the mobile nodes; as a node might be well within the transmission range of the main controller, yet have very little or no battery life. Such nodes should not be used to relay packets and should return to the main controller.
[0034] The present invention provides for nodes at the threshold of a connection to stop their mobility if breaking away from this connection would disrupt the node's communication with the main controller. For example, robot 2 in FIG. 1 is at threshold, as its direction of movement is away from the main controller. Its mobility would break its connection with the main controller as well as the connection of robot 6 with the main controller, since robot 2 connects robot 6 .
[0035] The present invention provides a means for nodes to constantly monitor the signal strength of the packets received from the neighboring nodes.
[0036] Accordingly, the present invention guarantees node connectivity, increases the area of coverage and the throughput in the network with minimum extra overhead under different mobility patterns.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
[0038] FIG. 1 is an illustrative embodiment of an exemplary ad hoc network topology in accordance with the present invention.
[0039] FIG. 2 is an illustration of the layered approach to implement the control layer method and system in accordance with the present invention.
[0040] FIG. 3 is a flow diagram illustrating the logic flow at each of the nodes in accordance with the present invention.
[0041] FIG. 4 is an exemplary information table in accordance with an embodiment of the present invention.
[0042] FIG. 5 is a diagrammatic view of an exemplary network topology for an illustrative example in accordance with the present invention at time t=1 s.
[0043] FIG. 6 is a table showing the illustrative data for the example at time t=1 s.
[0044] FIG. 7 is a table illustrating the update table generated at each of the individual nodes in the illustrative example at time t=1.2 s.
[0045] FIG. 8 is a table illustrating the data structure at the main controller in the illustrative example at time t=1.2 s.
[0046] FIG. 9 is a diagrammatic view illustrating the network topology of the illustrative example at time t=50 s.
[0047] FIG. 10 is a table illustrating the information table at time t=50 s for the illustrative example.
[0048] FIG. 11 is a table illustrating the update table at time t=50.4 s for the illustrative example.
[0049] FIG. 12 is a table illustrating the data structure at the main controller at time t=50.4 s for the illustrative example.
[0050] FIG. 13 is a diagrammatic view illustrating the network topology of the illustrative example at time t=100 s.
[0051] FIG. 14 is a table illustrating the information table at time t=100 s for the illustrative example.
[0052] FIG. 15 is a table illustrating the update table at time t=100.8 s for the illustrative example.
[0053] FIG. 16 is a table illustrating the data structure at the main controller at time t=100.8 s for the illustrative example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0054] The present invention provides a system and method for the exchange of control message among mobile nodes and a main controller and the ability to stop the mobility of the robots when their connections with the main controller, either directly or through another mobile node, are in danger of being lost. The decision to stop the mobility of a node is based on the signal strength and the energy level of the surrounding nodes.
[0055] With reference to FIG. 2 , the present invention is implemented in a control layer 10 that operates between the network routing layer 15 and data link layers 20 to provide for node connectivity.
[0056] In a particular embodiment, the robots and the main controller are deployed at the same location at the start of a search and rescue operation. The main controller remains stationary throughout the entire operation and the robots begin to explore the disaster zone.
[0057] Referring to FIG. 3 , which illustrates the flow diagram illustrating the logic at the local nodes in accordance with the present invention, after the main controller and the mobile nodes are stationed at the disaster site 25 , every mobile node broadcasts a periodic hello message with its energy information in a standard packet format 30 . The hello messages are exchanged based on a predetermined interval. The node receiving a broadcast message does not forward the packet, thus the packet is delivered only to the nodes that are within the transmission radius of the sender node. Each node that receives the hello messages 35 from its neighbors, calculates the signal strength at which the packet was received and inserts the energy value and power at which the packet was received in an information table 40 . An information table is maintained at every node, where, for each node in the network an entry is maintained. This table has fields corresponding to the neighboring node id, its normalized energy level, and the normalized power level at which the hello packet was received from that node. At periodic intervals every node in the network, computes the composite threshold for each of its neighboring nodes, based on the values in the information table 45 . The composite threshold refers to a combined value of energy and signal strength calculated using the following relationship:
((alpha*normalized_energylevel)+(I-alpha)*normalized_powerlevel)
where ALPHA is a weighting factor determined by the system.
[0058] In determining the values for the normalized_energylevel and the normalized_powerlevel, the battery power and signal power values stored in the information table of the nodes need to be normalized to the same scale before being used in the above given equation. The battery power is measured in joules and is usually a positive number in the range of zero to the maximum power of the battery. The signal strength is measured in decibels and is of the order of 10 −x , where the range of x depends on the wireless interface and other channel parameters. The battery power and the signal strength are converted to ratios, denoted as a fraction of the maximum energy and maximum signal strength possible according to the following relationship:
normalized_energylevel=energy of neighboring node÷maximum energy possible for this node
normalized_powerlevel=signal strength for this link÷maximum signal strength possible for any link from this node
[0059] The maximum possible values for node energy and signal strength of any link are pre-determined and remain constant for the entire duration of the application. The maximum possible value for the energy level would be the energy value of the batteries when fully charged. And the maximum possible value for signal strength for any link would be the signal power level calculated between two nodes that are very close to each other assuming ideal transmission conditions.
[0060] The value of ALPHA may be static or dynamic. A static value of ALPHA provides a constant weight factor for the energy and power levels of nodes and links, irrespective of the current nodes and network conditions. A more appropriate strategy is to dynamically change the value of ALPHA to adapt the calculation to reflect current network behavior. For example, at the start of the simulation, all nodes have energy values close to the maximum. In this case, it would be better to have a small ALPHA value, e.g. 0.1, thus giving more weight to the neighboring link power level. Similarly, when all the nodes are in close proximity to the main controller, the signal strength of the received packets would be close to maximum. An ALPHA value of 0.8 would be better, as the calculated composite threshold will be more biased toward energy values. To illustrate this aspect further, let us consider a more numerical example. Let us assume a network of 5 nodes and a main controller, with static a value of 0.5 at each node. With reference to the table in FIG. 4 , the values in the information table at node 1 along with their composite threshold values are given. As it can be seen from the table, node 4 has the best link with this node (normalized signal power of 0.63), while neighbor node 2 has the most energy (normalized energy value of 0.92). The table also shows the composite threshold for the neighbors of node 1 , calculated with a=0.5. This results in node 2 having the maximum value for composite threshold, and being chosen as the immediate parent for this node. The parent node is just the node having the maximum value for composite threshold among all the neighbors of a node and indicates the presence of a neighbor node through which a node can communicate with the main controller. In this case, it would have been better to choose node 4 as the parent node since it had better signal strength. An ALPHA value of 0.1 would have biased the calculation of composite threshold to the node with better power level, while an ALPHA value of 0.9 would have biased the calculation to the neighbor node with better energy level. Thus, in order to balance the biasing factor, ALPHA values are dynamically estimated. Each node has its own ALPHA value and is estimated based on the previous ALPHA value and the current data in the information table. The procedure is listed as an algorithm below and is run once every time the update table is updated by the nodes and sent to the main controller.
[0061] It is to be noted that the energy and power level values of the node with maximum composite threshold need not necessarily be the maximum energy and power level values. Thus, if the maximum energy value in the information table is greater than the energy value of the node with the maximum composite threshold. ALPHA value is increased by the fraction of the difference between these two values. An increase in ALPHA value would result in higher weighting for the energy values in the computation of composite threshold. Similarly, if the maximum value for power level in the information table is greater than the power level of the node with maximum composite threshold, ALPHA value is decreased by the fraction of difference between these two values.
[0062] Referring again to FIG. 3 , once determined, the value of the composite threshold is stored along with the corresponding neighbor id in the update table. Each node then forwards its update table to the main controller 50 . The main controller receives update tables from all nodes at periodic intervals and performs a local computation on each of the received tables to see if every node in the network has a connection to the main controller 50 . The main controller loops through every node in the network to check if it has a direct connection with the main controller or through any other intermediate node, or if it has such a connection, but is at the link threshold. The link threshold is the minimum composite threshold for the network below which the link is considered a weak link. The main controller sends a message to these nodes 55 , with its mobility flag set to false, thereby stopping the mobility of the node. Nodes that receive messages from the main controller with its mobility flag set to false, stop their mobility 60 (if not stopped already), and wait for a certain period of time to see if it receives a message from the main controller with mobility flag set to true, in which case it continues its mobility 65 . If this wait time expires, and the nodes do not receive a message from the main controller with mobility flag set to true, they begin to move towards the main controller as a preemptive measure.
[0063] In a specific embodiment, the main controller receives update tables from every node in the network once every predetermined update interval, wherein the predetermined interval is the time interval between successive update packets sent by the individual nodes. The information in these tables is copied into a data structure maintained at the main controller. For each node in the network the main controller maintains a data structure comprising the number of neighbors of that node, mobility flag that specifies if that node is mobile or not, an array of neighbor id's, composite threshold values and the sequence number of the update packet expected from that node. Use of sequence numbers for update packets is similar to the implementation of sequence numbers for TCP packets. Entries in this data structure are modified as and when update packets are received.
[0064] The main controller runs an algorithm once every predetermined interval to check for mobility status of every node in the network, wherein the predetermined interval is the time interval between successive loops through the algorithm at them main controller to check for mobility status of the nodes in the network. The algorithm loops through the information table of every node in the network, and checks for a connection to the main controller that is above the composite threshold. If no such link exists, then it finds the neighbor of this node that has the maximum value of composite threshold and looks in the information table of the neighbor node for a connection (The node that has the maximum value of composite threshold among all neighbors, should have its composite threshold greater than the link threshold). The algorithm stops the mobility of the mobile node, if after recursively iterating through the information table of all neighbors, it does not find a direct or multi-hop connection to the main controller.
[0065] If there is no direct link between any of the nodes and the main controller, the algorithm recursively loops through every safe neighbor to find a link to the main controller. Safe neighbors are neighbor nodes that have a composite threshold value greater than link threshold. This ensures maximum safe area of coverage without loosing contact with the main controller. By making sure that all nodes have a direct or routed link to the main controller, the algorithm also ensures that there is a communication link between individual nodes, i.e. a tree structure of the network is always maintained.
[0066] Accordingly, in a particular embodiment, the present invention uses a centralized mechanism to monitor the mobility of the nodes, and all nodes use the underlying distributed ad hoc routing protocol to exchange hello packets and send the computed information table to the main controller. However, it is the main controller that decides on the mobility of all the nodes based on the data in the information table, and hence this approach is classified as centralized.
[0067] In a particular embodiment, the present invention utilizes AODV as the routing layer protocol to provide for routing information between nodes. The forwarding of update tables to the main controller once every predetermined interval relies on the underlying routing protocol for the transmission. The functionalities at the MAC layer required by an ad hoc network control layer are very similar to that required by a wireless network. In a specific embodiment, the IEEE 802.11 standard for wireless LAN's is chosen as the Medium Access Control (MAC) layer protocol, while the routing layer protocol is chosen from one of the several protocol designed specifically for ad hoc networks. This specific embodiment is not meant to be limiting and other routing layer protocols and wireless network protocols are within the scope of the present invention.
[0068] Several variations are possible regarding the responsibilities of the main controller and the mobile nodes. In an additional embodiment of the invention, the proposed control layer is modified to work in a completely distributed manner. For instance, instead of computing the composite threshold at every node and sending this information to the main controller in an update table, each node could send its information table (consisting of neighbor id, energy level of the neighbor, and received signal power level), and the ALPHA value, and leave the computation to the main controller. This could help in reducing the computation time at the individual nodes at the expense of an increase in the routing overhead.
[0069] In yet another embodiment, the control layer algorithm can also be modified so that the mobile nodes can have complete mobility control. Instead of having the main controller validate the mobility of nodes by iterating through the update tables received from each node, the network could be flooded with update tables from each node, so that every node in the network has a copy of the update table of the other nodes. By doing this, the control of deciding on mobility is left entirely to the individual nodes rather than to the main controller.
[0070] In accordance with an exemplary embodiment of the present invention, consider the example of a 700 m×500 m disaster site being explored with a main controller 70 and 2 mobile robots, Node 1 75 and Node 2 77 , as shown with referenced to FIG. 5 . The main controller remains stationary during the entire course of the search and rescue operations. All three nodes exchange hello packets containing the node energy value, once every predetermined interval. The information table is maintained at each node and stores this energy information for its neighbors, along with the power level at which the packet was received. The power level of the received packets is used as an estimator of signal strength. Assuming the transmission range for a node to be 250 m, and a link threshold of 0.32, wherein the link threshold is the minimum value for the composite threshold, below which a link is considered to be a weak link. Let the interval between successive hello signals be 1 second, the interval between update tables sent to the main controller to be 1.2 seconds, and interval between the main controller monitoring the update table sent from the nodes to be 1.5 seconds. Also, ALPHA is set to 0.5 at all nodes, implying a constant weight factor between energy and power. The table as shown in FIG. 5 illustrates the values in the information table at node 1 , along with their composite threshold values. Assume all nodes move at a speed of 4 meters per second in a specific direction. Thus assuming that the nodes travel in a straight direction, they would be out of the transmission range of the main controller in 50 seconds. Nodes 1 and 2 are close to the main controller and their direction of movement is indicated. Hello messages are exchanged between the nodes, and data in the information table gets updated for each received hello message. The table of FIG. 6 shows the data stored in information table at time t=1. It is to be noted that energy and signal power values are normalized as previously explained, while updating the contents of the information table. At time t=1.2 s the function call to send the update table is evoked, that calculates composite threshold, estimates ALPHA value, and sends the update table to the main controller 70 . Using the equation for composite threshold previous given, the update tables are generated at the individual nodes as shown with reference to the table of FIG. 7 .
[0071] To further illustrate the calculation of composite threshold, let us take the example of node
1. Node 2 is a neighbor of node 1 with energy level of 0.95 and signal power of 0.9. Hence the composite threshold for this neighbor of node 1 would be:
(0.5*0.95)+(0.5*0.9) which is 0.925
[0073] After calculation of the composite threshold, each node estimates its ALPHA value. At node 1 , the neighbor that has the maximum value for composite threshold is the main controller (from update table). Thus the best_energylevel and best_powerlevel correspond to the energy and signal power values of this node, i.e, 0.96 and 0.92 respectively. Also, from the information table, it can be seen that the local_maxenergy and local_maxpower correspond to the values of the main controller. This implies that the current value of ALPHA is properly biased between energy and signal strength, and thus the ALPHA value for this node remains the same. Again among the neighbors of node 2 , the main controller has the maximum value for composite threshold. Variables best_energylevel and best_powerlevel correspond to values 0.93 and 0.9 respectively. But the values for local_maxenergy and local_maxpower correspond to 0.95 and 0.9 respectively. Despite having a greater energy value, node 1 doesn't have the maximum composite threshold value. Thus the alpha value is biased to give more weight to the energy value in the calculation of composite threshold. Since max(normalized energy)>normalized energy of node with max(composite threshold),
[0074] ALPHA=ALPHA+(1−best_energylevel/local_maxenergy)=0.5+(1−0.93/0.95)=0.521 The ALPHA value for node 1 remains at 0.5, while node 2 now has an ALPHA value of 0.521, increased weight for energy value of neighbors. After ALPHA estimation, each node sends its update table to the main controller. On receiving these tables from the individual nodes, the main controller updates its data structure to reflect the current network topology. Thus at t=1.2 s, the main controller has a data structure similar to that of the table shown in FIG. 8 . At every predetermined interval (=1.5 in this case) the main controller runs its local algorithm to check for links from all nodes to itself. From the table in FIG. 8 , it can be seen that nodes 1 and 2 , both have a direct connection with the main controller, and is above the link threshold (=0.32). So both nodes can remain mobile, and the mobility flag for these nodes is set to true.
[0075] FIG. 9 represents the network topology at time t=50.0 s. The table shown in FIG. 10 illustrates the information table at nodes 1 and 2 , updated based on the hello messages received from their neighbors at time t=50.0 seconds. Again at t=50.4 s, the function call to update table is evoked. Since ALPHA values are dynamically estimated every UPDATE INTERVAL, using the value of 0.5 and 0.521 for nodes 1 and 2 , estimated at t=1.2 s would not be appropriate. Thus ALPHA is assumed to be 0.2 at t=50.0 s. The generated update table is shown in the table of FIG. 11 . ALPHA values are estimated in the same way as in the previous case and is not shown here. At t=50.4 s, the nodes forward their update tables to the main controller, where the local data structure is updated based on the data received from the nodes in the network. The updated data structure at the main controller is shown in the table of FIG. 12 .
[0076] The main controller executes its local algorithm at again at t=51 s. As can be seen from the table of FIG. 12 , node 1 has a direction with the main controller, but the composite threshold value is at the link threshold. So the algorithm loops through the update tables of other neighbors of this node, which have a composite threshold value greater than link threshold, for a connection to the main controller. The only other neighbor for node 1 is node 2 , and its composite threshold value is greater than link threshold. Hence the algorithm checks the neighbors list of node 2 for a strong link to the main controller. But node 2 has an even weaker connection to main controller (composite threshold=0.24), and hence the algorithm stops the mobility of node 1 since its only connection to the main controller is at threshold. The mobility flag of node 1 is set to false, and a message is sent to the node with the mobility flag.
[0077] Similarly, the algorithm looks for a connection from node 2 to the main controller. The direct link from node 2 to the main controller is below the link threshold (=0.24), and the algorithm checks for a connection to main controller through other neighbors of this node which have threshold values greater than link threshold. Neighbor node 1 has a connection with the main controller, which is at link threshold. But since its mobility has already been stopped, and is not in danger of breaking away from the main controller, the algorithm sets node 1 as the parent node of 2 , and node 2 continues to have its mobility flag set to true.
[0078] FIG. 13 presents the network topology at t=100 s. It is to be remembered that node 1 has its mobility flag set to false, and node 2 has its mobility based on node 1 , i.e. node 2 has a link to the main controller through node 1 . ALPHA value is assumed to be 0.3 at t=100 s.
[0079] Based on the hello messages exchanged between the nodes at t=100 s, the information table of each node gets updated and is shown in the table of FIG. 14 . It is to be noted that there is no entry for the main controller in the table of node 2 , and this is due to the fact that node 2 has moved well beyond the transmission range of main controller and the hello messages broadcasted by the main controller are not received at node 2 . At t=100.4 s, the update table function is evoked by every node, which generates the update table shown in FIG. 15 for that node, estimates ALPHA value and sends out the update table to main controller. The contents of the data structure at the main controller get updated on receiving these tables form the mobile nodes and are shown in the table of FIG. 16 . Node 1 has its mobility flag set to false and the algorithm at the main controller is not able to find any better link to the main controller (this occurs if a node with a strong link to the main controller moves within the transmission range of node 1 ). But, node 2 now has only one neighbor, node 1 and this link has a composite threshold value equal to link threshold. Node 2 can still communicate with the main controller through node 1 , but both the links are at threshold limits.
[0080] The algorithm at the main controller iterates through the data collected from update tables and checks for mobility of the nodes. A timer is attached to every node to keep track of the duration for which it has been stopped. Based on this time value, the main controller can issue callback functions to the nodes requesting them to move towards the base.
[0081] This detailed exemplary embodiment is illustrative in nature and is not intended to limit the scope of the present invention.
[0082] It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
[0083] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. Now that the invention has been described, | In accordance with the present invention is provided, a method to assure node connectivity in an ad hoc wireless network comprising a wireless main controller, a plurality of wireless nodes having a plurality of neighboring nodes and a plurality of wireless links connecting the wireless main controller, the plurality of wireless nodes and the plurality of neighboring nodes. The proposed method includes, computing a composite threshold for each of a plurality of neighboring nodes of a plurality of nodes, assigning a mobility to each of the plurality of nodes based on the composite threshold for each of the plurality of neighboring node and using the mobility assigned to each of the plurality of nodes to assure node connectivity in the ad hoc network. | 8 |
BACKGROUND OF THE INVENTION
[0001] The Epoxy Intermediates and resins industry (Encyclopedia of Chemical Technology, Volume 9, Fourth Edition, John Wiley & Sons Page 370) is a multibillion dollar business that is based on the following technology that involves no less than ten chemical reactions.
Benzene+propylene→isopropyl benzene Isopropyl benzene→cumene hydroperoxide Cumene hydroperoxide→phenol+acetone Phenol+acetone→“Bis-A” or ( Phenol+formaldehyde→“Bis-F”) Propylene+chlorine→allyl chloride Allyl chloride+sodium hydroxide+chlorine→propylene chlorohydrins Propylene chlorohydrins+sodium hydroxide→epichlorohydrin Bis-A+epichlorohydrin+NaOH→“Bis-A glycidol ether” Bis-A glycerol ether+Bis-A→epoxy resin Sodium chloride+water→chlorine+sodium hydroxide
[0012] Several aspects of the above reaction sequence have negative process implications with regards to yields, chlorinated byproducts, hydraulic load and biological hazards. These include but are not limited to the following: (a) benzene is a known carcinogen, (b) Bis-A is an endocrine disrupter (mimics estrogen). Recent research (Current Biology, Volume 13, page 546, 2003) has shown that abnormalities in developing mouse eggs occurred at levels of bisphenol A to which people are commonly exposed. Similar aberration in human eggs would lead to miscarriages and birth defects, and (c) chlorination of propylene to allyl chloride and the addition of hypochlorous acid to allyl chloride yield higher chlorinated byproducts resulting in ˜⅓ pounds of chlorinated waste per pound of epichlorohydrin. In addition, the process requires a chlor-alkali facility, hence a local source of salt and huge volumes of water. The products and processes of the present invention ameliorate if not eliminate some of the disadvantages of prior art of epoxy products and processes.
BRIEF DESCRIPTION OF THE INVENTION
[0013] The present invention relates to the preparation of ethers and esters of diallylphenols and the epoxidation of the diallyl moiety to provide bis-epoxide ether and ester intermediates useful in the preparation of epoxy resins. The epoxy ethers and esters of carboxylic, carbonic, phosphoric and sulfuric acids of the present invention are represented by the following formulas:
where Ar is a trivalent aromatic radical of 6-20 carbon atoms, Ar′ is a bridged diaromatic radical having the formula Ar—Y—Ar and Y is O, CO, S, SO 2 , —(CH 2 )y , or —C(R″) 2 — and y is from 0 to 6, and R and R′ are the same or different alkyl aryl, alkylene aryl, arylene alkyl, alkylene alkoxy, alkylene aryloxy, arylene alkoxy and arylene aryloxy aryl, radicals having from 6-20 carbon atoms, X is —R, —COR, —COOR, —SO 2 R, —PORR′.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The synthesis of diepoxides described in the present invention requires the introduction of the allylic moiety to the aromatic ring that is converted in a subsequent reaction to the 2,3-epoxypropyl moiety. The allylation of phenols is well documented in the literature utilizing allyl aryl ethers, that on heating, rearrange to allyl phenols. The reaction is called the Claison Rearrangement (Advanced Organic Chemistry, 3 rd Edition, by J. March, John Wiley & Sons 1985). Allyl aryl ethers are readily prepared from the phenate salt and allyl derivatives.
C 6 H 5 OH+CH 2 ═CHCH 2 X+base→C 6 H 5 OCH 2 CH═CH 2 where X=chloride, bromide, acetate, tosylate etc. C 6 H 5 OCH 2 CH═CH 2 +heat→CH 2 ═CHCH 2 —C 6 H 5 OH
[0017] The preparation of the novel diepoxides described in the present invention utilizes the Claison rearrangement and the allyl ether synthesis in one of two ways depending on the structure of the aromatic substrate. If the starting aromatic is a monophenol, the allylation-rearrangement is carried out a second time to obtain the diallyl product as illustrated below for phenol.
Phenol+allyl chloride+base→allyl phenyl ether Allylphenyl ether+heat+solvent→2-allyl phenol 2-allyl phenol+allyl chloride→2-allyl phenyl ether 2-allyl phenyl ether+heat+solvent→2,6-diallyl phenol
[0022] The diallylphenol is derivatized to either the desired ether or ester and oxidized to the diepoxide with a peracid, hydrogen peroxide/catalyst, t-butyl hydroperoxide/catalyst system that are well documented in the literature. If the starting aromatic is a diphenol, the latter is diallylated to the bis ether and rearranged as described above to the diallyl diphenol. Derivatization to either a diether or diester as described above followed by oxidation yields the desired diepoxide. The latter process with diphenols is advantageous in that two process steps are eliminated (an allylation and a rearrangement). The following are examples of phenols and diphenols that may be used as starting materials for the invention: phenol, 4-methoxyphenol, 4-methylphenol, 2,6-dichlorophenol, 2-naphthol, 4-cyanophenol, 4-hydroxybiphenyl, 4-tert.butyl phenol, 4-dodecylphenol, 3-butoxyphenol, 3,5-dimethylphenol, 3-trifluoromethylphenol, 2,4-diethylphenol, catechol, hydroquinone, resorcinol, 2,2-(4-hydroxyphenyl)propane, 4,4′-sulfonyldiphenol, 4,4′-dihydroxybenzophenone, 4,4′-hydroxyphenylmethane, 4-hydroxyphenyl ether, 2-hydroxyphenylthioether, 4,4′dihydroxybiphenyl.
[0023] The condensation of the bis-epoxides of this invention with diphenols, e.g., bis-phenol-A, bis-phenol-F,4-hydroxyphenyl sulfone, 4,4*dihydroxybenzophenone, 4,4′dihydroxybiphenyl, and 1,4-(4-hydroxyphenyl)butane, with dicarboxylic acids, e.g., isophthalic acid, succinic acid and cyclohexane dicarboxylic acids, with amino phenols, e.g, 4-aminophenol, 4-amino-4*-hydroxyphenylether, and 4-amino-4′-hydroxybiphenyl, with hydroxycarboxylic acids, e.g., 4-hydroxybenzoic acid, and 6-hydroxy-2-naphthoic acid, with amino acids, e.g., 4-aminobenzoic acid, with diamines, e.g., 4,4′-diaminophenyl ether, 1,3-diaminobenzene and 1,3-diaminopropane or with disulfonamides, e.g., 1,3-benzenedisulfonic acid: bis-N-methylamide results in new and valuable epoxy resins for protective coatings, structural composites, electrical laminates and adhesives. The chemistry provides the opportunity to manufacture resins with fewer chemical transformations, less capital and a reduction in the waste load associated with the bis-A epichlorohydrin technology. The resins can be obtained from the bis-epoxides using condensation procedures known in the art. An example of a resin synthesis from readily available starting materials using the diepoxide route of the present invention is outlined below:
1. Toluene→phenol (T. Shikada, et al J. Chem. Soc., Chem. Commun, 1994) 2. Propylene→allyl acetate 3. Phenol+sulfuric acid→4,4′- sulfonyldiphenol 4. 4,4′-Sulfonyldiphenol→4-alloxyphenyl sulfone 5. 4-Alloxyphenyl sulfone→3-allyl-4-hydroxyphenyl sulfone 6. 3-Allyl-4-hydroxyphenyl sulfone→3-allyl-4-methoxyphenyl sulfone 7. 3-Allyl-4-methoxyphenyl sulfone→3- (2,3-epoxypropyl)-4-methoxyphenyl sulfone 8. 3- (2,3-Epoxypropyl)-4-methoxyphenyl sulfone+(diphenol, diacid, etc.,)→epoxy resin
[0032] The following examples further illustrate novel epoxides of the present invention:
EXAMPLE 1
Preparation of 2,6-D(2,3-epoxypropyl)anisole
[0033] 2,6-Diallylphenol was prepared via reacting 2-allylphenol with an allyl halide to form 2-allylphenyl ether. Refluxing the latter in o-dichlorobenzene for 24-48 hrs. gave 2,6-diallylphenol. The desired phenol was purified by distillation, bp 91-92 C.(1 mm). MS m/z 174 (M+ calcd for C 12 H 14 O=174). H NMR (300 MHz, CDCl 3 ), d 3.48 (d, 4, CH 2 ), 5.15-5.38 (m, 4,vinyl), 5.98-6.18 (m, 2, CHvinyl), 6.85-7.15 (m, 3 aromatic). 2,6-Diallylphenol (5.2 g, 0.03 mol) was diluted with methanol (50 ml) and sodium hydroxide added to the phenol solution. Iodomethane (5.0 g, 0.03 mol.) was added to the solution and stirred overnight at room temperature. The methanol solution was diluted with water and the product extracted with hexane, dried over MgSO 4 , filtered and evaporated to give 2,6-diallylanisole. MS m/z 188 (M+ calcd for C 13 H 16 O=188). H NMR (300 MHz, CDCl 3 ) d 3.45-3.55 (d, 4, CH 2 ), 3.60 (s, 3, CH 3 ), 5.10-5.20 (d, 4, CH 2 ), 6.00-6.16 (m, 2, CH vinyl), 7.07-7.20 (m, 3, aromatic). 2,6-Diallylanisole was oxidized with meta-chloro perbenzoic acid as follows: MCPBA (˜70%, 5.73 g) was dissolved in dichloromethane (50 ml) and dried over MgSO 4 . After filtration of the MgSO 4 , 2,6-diallylanisole (1.88 g, 0.01 mol) was added to the MCPBA solution and stirred for 24-48 hrs. at room temperature. The precipitate, m-chlorobenzoic acid was filtered and, the dichloromethane solution washed with dilute sodium bisulfite and dilute potassium carbonate and dried over MgSO 4 . After filtration of the MgSO 4 , the dichloromethane was evaporated to give the liquid diepoxide, bp 138° C. (1 mm). MS m/z 220 (M+ calcd for C 13 H 16 O 3 =220). H NMR (300 MHz, CDCL 3 ) d 2.60-2.70 (m, 2, CH 2 epoxypropyl), 2.75-3.10 (m, 6, CH 2 epoxypropyl), 3.25-3.50 (m, 2, CH epoxypropyl), 3.82 (s, 3, OCH 3 ), 7.05-7.25 (m, 1, aromatic), 7.40-7.60 (m, 2, aromatic).
EXAMPLE 2
Preparation of 2,6-di(2,3-epoxypropyl phenyl ethoxyethyl ether
[0034] 2,6-Diallylphenol (5.2 g, 0.03 mol) was diluted with 95% ethanol (50 ml). Sodium hydroxide (1.4 gm, 0.03 mol) was added to the phenol solution followed by 2-chloroethylether (3.8 gm, 0.035 mol). The reaction mixture was refluxed for 48 hrs, cooled, diluted with water, extracted with hexane and dried over MgSO 4 . Filtration of the MgSO 4 and evaporation of the hexane gave 5.1 g of 2,6-diallylphenyl ethoxyethyl ether. MS m/z 246 (M+ calcd for C 16 H 22 O 2 =246). H NMR (300 MHz, CDCl 3 ) d 1.30 (3, t, CH 3 ), 3.40-3.55 (4, m, CH 2 allyl), 3.65-3.75 (2,q, OCH 2 methyl), 3.80 (q, 2, OCH 2 ), 4.00(q, 2, OCH 2 ), 5.05-5.25 (m, 4, CH 2 vinyl), 5.90-6.20 (m, 2, CH vinyl), 7.05-7.20 (m, 4, CH 2 vinyl), 7.05-7.20 (m, 3, aromatic). Oxidation of the product as described in Example 1 gave 2,6-di-(2,3-epoxypropyl)phenyl ethoxyethyl ether as an oil. MS m/z 278 (M+ calcd for C 16 H22O 4 =278). H NMR (300 MHz, CDCl 3 ) d 1.25 (t, 3, CH 3 O, 2.65-2.85 (m, 4, epoxypropyl CH 2 ), 2.90-3.15 (m, 4, epoxypropyl CH 2 ), 3.21-3.35(m, 2, epoxypropyl CH), 3.65 (q, 2, OCH 2 ), 3.80 (q, 2, OCH 2 ), 4.00 (q, 2, OCH 2 ), 5.33 (s, 3, OCH 3 ), 7.05-7.33 (m, 3, aromatic).
EXAMPLE 3
Preparation of 4-methyl-2,6-di(2,3-epoxypropyl)phenyl methyl ether
[0035] 4-Methyl-2,6-diallylphenyl methyl ether was prepared from p-creosol as described for 2,6-diallylphenol in Example 1. MS m/z 202 (M+ calcd for C 14 H 18 O 2 =202). H NMR(300 MHz, CDCL 3 ) d 2.35 (s, 3, CH 3 ), 3.45 (d, 4, OCH 2 ), 3.57 (s. 3, OCH 3 ), 5.10-5.29 (m, 4, CH 2 vinyl), 5.95-6.20 (m, 2, CH 2 vinyl), 6.95, (s, 2, aromatic). Oxidation of the product as described in Example 1 gave 4-methyl-2,6-di-(2,3-epoxypropyl) phenyl anisole as an oil. MS m/z 234. (M+ calcd for C 14 H 18 O 4 =234). H NMR (300 MHz, CDCL 3 ) d 2.30 (s, 3, CH 3 ), 2.60 (d, 2, epoxypropyl), 2.80-3.00 (m, 6, epoxypropyl), 3.20-3.30 (m, 2, epoxypropyl), 3.75 (s, 3, OCH 3 ), 7.05 (s, 2, aromatic).
EXAMPLE 4
Preparation of 2,6-di(2,3-epoxypropyl) phenyl benzyl ether
[0036] 2,6-Diallylphenol (3.48 gm, 0.025 mol) was diluted with methanol (50 ml) and sodium hydroxide (0.8 gm 0.02 mol) was added to the solution followed by the benzyl chloride (3.60 gm, 0.2 mol.). The solution was refluxed for 2 hr, cooled, poured onto water and extracted with hexane. After washing with water and dilute sodium hydroxide, the organic layer was dried over MgSO 4 , filtered and evaporated to give 2,6-diallylphenyl benzyl ether. MS m/z 264 (M+ calcd for C 19 H 20 O=264). H NMR (300 MHz, CDCL 3 ) d 3.45-3.55 (d, 4, CH 2 allyl), 4.85 (s, 2, CH 2 benzyl), 5.05-5.20 (m, 4, CH 2 vinyl), 5.96-6.15 (m, 2, CH vinyl), 7.10-7.25 (m, 3, aromatic), 7.35-7.70 (m, 5, aromatic). Oxidation of the product as described in Example 1 gave 2,6-di(2,3-epoxyypropyl) phenyl benzyl ether as an oil. MS m/z 296 (M+ calcd for C+H 20 O 3 =296). H NMR (300 MHz, CDCl 3 ) d 2.60-2.70 (m, 2, CH 2 epoxypropyl), 2.75-3.10 (m, 6, CH 2 epoxypropyl), 2.31-2.46 (m, 2, CH 2 epoxypropyl), 4.75 (s, 2, CH 2 O), 7.10-7.25 (m, 1, aromatic) 7.45-7.60 (m, 2, aromatic), 7.60-8.15 (m, 5, aromatic).
EXAMPLE 5
Preparation of 2,6-(2,3-epoxypropyl) phenyl-4-cyanophenyl ether
[0037] 2,6-Diallylphenol (3.8 gm, 0.02 mol) was oxidized with m-chloroperbenzoic acid as described in Example 1 to give 2,6-di(2,3-epoxypropyl)phenol. MS m/z 206 (M+ calcd for C 12 H 14 O 3 =206). H NMR (300 MHz, CDCl 3 ) d 2.65 (d, 2, CH 2 epoxypropyl) 2.75-2.96 (CH 2 epoxypropyl), 3.12 (d, 2, CH epoxypropyl), 3.25-3.35(m, 2, CH epoxypropyl), 6.80 (t, 1, aromatic), 7.10 (d, 2, aromatic). The product 2,6-di(2,3-epoxypropyl)phenol was diluted with dimethylacetamide (50 ml) and neutralized with sodium hydroxide. 4-Fluorobenzonitrile (1 equivalent of the phenol) was added and the mixture heated and stirred overnight at 50° C. After cooling, the reaction was diluted with ethyl acetate and washed with water (4×), dried over MgSO 4 and evaporated to give 2,6-di(2,3epoxypropyl)phenyl 4-cyanophenyl ether. MS m/z 307 (M+ calcd for C 19 H 17 O 3 N=307). H NMR (300 MHz, CDCl 3 ) d 2.50, (d, 2, CH 2 epoxypropyl CH 2 ), 2.65-2.90 (m, 4, CH 2 epoxypropyl), 3.15-3.30 (m, 2, CH 2 epoxypropyl), 3.45-3.75 (m, 2, epoxypropyl CH), 6.75-7.06 (m, 3, aromatic), 7.00-7.75 (m, 4, aromatic).
EXAMPLE 6
Preparation of 2,6-di(epoxypropyl)phenyl octadecyl ether
[0038] Diallylphenol (3.48 gm, 0.02 mol) was diluted in dimethyl sulfoxide (50 ml) and sodium hydroxide (0.8 gm, 0.02 mol) added to the solution followed by 1-chlorooctadecane (5.78 gm, 0.02 mol) and heated at 80 C. for 2 hrs. After cooling and diluting with water, the reaction mixture was extracted with hexane, dried over MgSO 4 filtered and evaporated to give the desired product. MS m/z 426. (M+ calcd for C 30 H 50 O=426). H NMR (300 MHz, CDCl 3 ) d 0.80 (t ,3, CH 3 ), 1.25 (s, 32, CH 2 ).1.75-1.80 (m, 2, CH 2 ), 3.30-3.40 (d, 4, CH 2 ), 3.70-3.80 (t, 2, OCH 2 ), 5.05-5.21(m, 2, CH 2 vinyl), 5.95-6.10 (m, 2,CH 2 vinyl), 7.00-7.20(m, 3, aromatic). Oxidation with MCPBA as described in Example 1 gave 2,6-di(epoxypropyl)phenyl octadecyl ether. MS m/z 458 (M+ calcd for C 30 H 50 O 3 =458). H NMR (300 MHz, CDCl 3 ) d 0.80 (t, 3, CH 3 ), 1.25 (s, 30, CH 2 ), 2.60-2.70 (m, 2, CH 2 epoxypropyl), 2.75-3.10 (m, 6, CH 2 epoxypropyl), 3.20-3.30 (m, 2, epoxypropyl CH), 3.55-3.75 (t, 2, CH 2 ), 7.10-7.25 (m, 1, aromatic), 7.40-7.60 (m, 2, aromatic).
EXAMPLE 7
Preparation of 4-toluic acid: 2,6-di(2,3-epoxypropyl) phenyl ether
[0039] 4-Toluyl chloride (3.09 gm, 0.02 mol) was diluted with 1,2-dichloromethane (50 ml) and added to a solution of triethylamine (4 ml) and 2,6-diallylphenol (3.48 gm, 0.02 mol) in 1,2-dichloromethane (40 ml) at room temperature. After the addition was complete, the reaction mixture was refluxed for 1 hr, cooled and the organic solution washed with water (2×), dried over MgSO4 and evaporated to give 4-toluic acid: 2,6-diallylphenyl ester. MS m/z 292 (M+ calcd for C 20 H 20 O 2 =292). H NMR(300 MHz, CDCl 3 ) d 2.50(s, 3, CH 3 ), 3.20-3.35 (d, 4, CH 2 ), 5.00-5.15 (m, 4, CH 2 , vinyl), 5.85-6.10 (m, 2, CH vinyl), 8.20-8.40 (m, 2, aromatic). Oxidation of the product as described in Example 1 gave 4-toluic acid: 2,6-(2,3-epoxypropyl)phenyl ester. MS m/z 324 (M+ calcd for C 20 H 20 O 4 =324). H NMR (300 MHz, CDCl 3 ) d 2.50 (s, 3, CH 3 ), 2.40-2.50 (m, 2, CH 2 epoxypropyl), 2.65-2.95 (m, 6, CH 2 epoxypropyl), 3.25-3.45 (m, 2, CH epoxypropyl) 7.35-7-75 (m 5, aromatic), 8.21-8.40 (d, 2, aromatic).
EXAMPLE 8
Preparation of 4-toluenesulfonic acid: 2,6-di(2,3-epoxypropyl)Phenyl ester
[0040] Triethylamine (4 ml) and 4-toluenesulfonyl chloride (3.80 gm, 0.02 mol) were diluted with 1,2-dichloromethane (50 ml) and 2,6-diallylphenol (3.48 gm, 0.02 mol), dissolved in 1,2-dichloromethane (10 ml), was added drop wise to the phenol-triethylamine solution at room temperature and then refluxed for 1 hr. The reaction mixture was cooled, washed with water and dried over MgSO 4 , filtered and evaporated to give 4-toluenesulfonic acid: 2,6-diallylphenyl ester as an oil. Purification was carried out via filtering a hexane solution of the ester through silica gel. MS m/z 328 (M+ calcd for C 19 H 20 O 3 S=328). H NMR (300 MHz, CDCl 3 ) d 2.50 (s, 3, CH 3 ), 3.25-3.35 (d, 4, CH 2 ), 4.95-5.10 (m, 4, CH 2 vinyl), 5.75-5.90 (m, 2, CH, vinyl), 7.10-7.25 (m, 3, aromatic), 7.85-7.95 (m, 2, aromatic). Oxidation of product as described in Example 1 gave 4-toluenesulfonic acid 2,6-di(2,3-epoxypropyl)phenyl ester. MS m/z 360 (M+ calcd for C 19 H 20 O 5 S=360. H NMR (300 MHz, CDCl 3 ) d 2.45-2.55 (m, 2, CH 2 epoxypropyl), 2.50 (s, 3, CH 3 ), 2.35-2.95 (m, 6, CH 2 epoxypropyl), 3.21-3.35 (m, 2, CH epoxypropyl), 7.25-7.45 (m, 5, aromatic), 7.85-7.95 (d, 2, aromatic).
EXAMPLE 9
Preparation of 2,6-di(2,3-epoxypropyl)phenyl methyl carbonate
[0041] 2,6-Diallylphenol (3.48, 0.02 mol) and triethylamine (4 ml) was diluted with 1,2-dichloromethane (50 ml). Methyl chloroformate (2.00 gm, 0.027 mol) was diluted with 1,2-dichloromethane (10 ml) and added drop wise to the phenol-amine solution. After the addition was complete, the reaction was refluxed for 1 hr, cooled and poured onto water. The organic layer was washed with water (2×) dried over MgSO 4 and evaporated to give 2,6-diallylphenyl methyl carbonate. MS m/z 232 (M+ calcd for C 15 H 16 O 3 =232). H NMR (300 MHz, CDCl 3 ) d 3.30-3.40 (d, 4. CH 2 ), 3.90 (s, 3, CH 3 ), 5.05-5.20 (m, 4, CH 2 vinyl), 5.85-6.00 (m, 2, CH vinyl), 7.10-7.27 (m, 3, aromatic). Oxidation of the product as described in Example 1 gave 2,6-di(2,3-epoxypropyl)phenyl methyl carbonate as an oil. MS m/z 264 (M+ calcd for C 14 H 16 O 5 =264). H NMR (300 MHz, CDCl 3 ) d 2.60-2.70 (m, 2, CH 2 epoxypropyl), 2.40-2.90 (m, 6, CH 2 epoxypropyl), 3.25-3.40 (m, 2, CH 2 epoxypropyl), 3.85 (s, 3, OCH 3 ), 7.30-7.65 (m, 3, aromatic).
EXAMPLE 10
Preparation of 2,6-(2,3-epoxypropyl)phenyl diethyl phosphate
[0042] 2,6-Diallylphenol (3.16 gm, 0.018 mol) was diluted with toluene(50 ml) and sodium hydroxide (0.72 gm, 0.018 mol) added to the solution. The reaction flask was equipped with a Dean and Stark apparatus and refluxed for 1 hr to remove water and to form an anhydrous solution of the phenate salt. After cooling, diethyl chlorophosphate, (3.45 gm) was added and the solution stirred overnight. Filtration of the solids and evaporation of the toluene gave 2,6-diallylphenyl diethyl phosphate. MS m/z 310. (M+ calcd for C 16 H 23 PO 4 =310). H NMR (300 MHz, CDCl 3 ) d 1.30-1.45 (t, 6, CH 3 ), 3.66-3.72 (d, 4, CH 2 ), 4.20-4.49 (m, 4, OCH 2 ), 5.15-5.30 (m, 4, CH 2 vinyl), 5.90-6.16 (m, 2, CH vinyl), 7.20 7.30 (m, 3, aromatic). Oxidation of the product as described in Example 1 gave 2,6-(2,3-epoxypropyl)phenyl diethyl phosphate. MS m/z 342 (M+ calcd for C 16 H 23 PO 6 =342). H NMR (300 MHz, CDCl 3 ) d 3.65 (t, 6, CH 3 ), 2.55-2.65 (m, 2, CH 2 epoxypropyl), 2.75-2.85 (m, 2, CH 2 epoxypropyl), 2.90-3.30 (m, 4, CH 2 epoxypropyl), 3.40-3.55 (m, 2, CH epoxypropyl), 4.10-4.35 (m, 4, OCH 2 ), 7.05-7.25 (m, 1, aromatic), 7.40-7.60 (m, 2, aromatic).
EXAMPLE 11
Preparation of 2,2-{3-(2,3-epoxypropyl)4-methoxyphenyl}propane
[0043] Bis-A {2,2-bis-(4-hydroxyphenyl) propane) was converted to the diallyl ether via reaction of the diphenate salt with allyl chloride. The diallyl ether of Bis-A was heated in refluxing o-dichlorobenzene for 48 hrs to yield 2,2-bis(3-allyl4-hydroxyphenyl)propane. MS m/z 308 (M+ calcd for C 21 H 24 O 2 =308). The diphenol was converted to the dimethyl ether via reaction with methyl iodide as described in Example 2. MS m/z 336 (M+ calcd for C 23 H 28 O 2 =336). H NMR (300 MHz, CDCl 3 ) d 1.70 (s, 6, CH 3 ), 3.37 (m, 4, CH 2 allyl), 3.82 (s, 6, OCH 3 ), 4.92-5.05 (m, 4, CH 2 vinyl), 5.85-6.15 (m, 2, vinyl), 6.70-7.05 (m, 6, aromatic). Oxidation of the diallyl derivative as described in Example 1 gave 2,2-{bis(3,3-epoxypropyl)4-methoxyphenyl}propane. MS m/z 353 (M+ —CH 3 ) {Calcd for C 23 H 28 O 4 =368}. H NMR (300 MHz, CDCl 3 ) d 1.60 (s, 6, CH 3 ), 2.25 (d, 2, CH 2 epoxypropyl) 2.60-2.75 (m, 4, CH 2 epoxypropyl), 2.85-2.95 (m, 2, CH 2 epoxypropyl), 3.15-3.22 (m, 2, CH epoxypropyl) 3.83 (s, 6, OCH 3 ), 6.75 (d, 2, aromatic), 7.10 (d, 4, aromatic).
EXAMPLE 12
Preparation of 4-methoxy-3-(2,3-epoxypropyl)phenyl sulfone
[0044] 4,4*-Sulfonyldiphenol (25 gm, 0.10 mol) was dissolved in methanol (200 ml) and sodium hydroxide (8.0 gm, 0.20 mol) was added and stirred until the solution was homogeneous. Allyl chloride (20mL 0.25 mol) was added and the solution heated and stirred at ˜45° C. until the reaction was complete. The reaction was poured onto water and extracted with ethyl acetate. The organic extract was washed with water (2×), dried, recrystallized from aqueous acetone to give 4-alloxyphenyl sulfone, mp 140-142° C. MS m/z 330 (M+ calcd for C 18 H 18 O 4 S=330). H NMR (300 MHz,CDCl 3 ) d 4.56 (d, 4, OCH 2 ), 5.27-5.44 (m, 4, vinyl), 5.93-6.08 (m, 2, CH vinyl), 6.95 (d, 4, aromatic), 7.82 (d, 4, aromatic). 4-Allylphenyl sulfone (19.5 gm, 0.59 mol) was refluxed in o-dichlorobenzene for 60 hrs (weekend) to give after solvent evaporation and recrystallization from hexane -1,2-dichloromethane gave 3-allyl-4-hydroxyphenyl sulfone, mp 154-156 C. MS m/z 330 (M+ calcd for C 18 H 18 O 4 S=330). H NMR (300 MHz, DMSO-d 6 ) d 3.30 (d, 4, CH 2 ) 5.20 (d, 4, vinyl), 5.91-6.00 (m, 2, vinyl), 6.85 (d, 1, aromatic), 7.57 (d, 2, aromatic). 3-Allyl-4-hydroxyphenyl sulfone (4.5 gm, 0.0134 mol) was dissolved in dimethylacetamide (25 ml) and powdered sodium hydroxide added to generate the diphenate salt. When the solution was homogeneous, methyl iodide (3.87 gm, 0.028 mol) was added and the reaction mixture heated at ˜40° C. for 40 hr. The reaction was poured onto hexane. The hexane solution was washed with water (3×), dried over MgSO 4 and the solvent evaporated to give 4-methoxy-3-allylphenyl sulfone mp 82-85 C. MS m/z 358 (M+ calcd for C 20 H 22 O 4 S=358). H NMR (300 MHz, CDCl 3 ) d 3.35 (d, 2, aromatic), 3.85 (s, 3, CH 3 ), 4.85-5.10 (m, 4, CH 2 vinyl), 5.85-6.10 (m, 2, CH vinyl), 6.88 (d, 2, aromatic), 7.65-7.80 (m, 3, aromatic). 4-Methoxy-3-allylphenyl sulfone (2.0 g, 0.0056 mol) was oxidized as described in Example 1 to give 4-methoxy-3-(2,3-epoxypropyl)phenyl sulfone, mp 105-108° C. MS m/z 390 (M+ calcd for C 20 H 22 O6S=390). H NMR (300 MHz, CDCl 3 ) d 2.53 (t, 2, CH 2 ), 2.76 (t, 2, CH 2 ), 2.80-2.97 (m, 4, CH 2 ), 3.85 (s, 6, OCH 3 ), 6.92 (d, 2, aromatic), 7.72-7.85 (m, 2, aromatic). | The present invention relates to the preparation of ethers and esters of diallylphenols and the epoxidation of the diallyl moiety to provide bis-epoxide ether and ester intermediates useful in the preparation of epoxy resins. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a process for the solubilization of phosphate rock or phosphate containing materials, more precisely to a process for the solubilization of phosphate containing substances which until now had been difficult to accomplish by conventional methods because of foreign matter present.
DESCRIPTION OF THE PRIOR ART
Solubilizing concentrated phosphatic rock with sulphuric acid to get calcium sulphate and calcium phosphate is already known. However, such solubilization is hindered when the raw materials used have a high content of foreign matter, such as ferric oxide, alumina, calcium fluoride and silica, due to the formation of colloidal solutions that are difficult to filter out. Furthermore, after time in storage the end product tends to suffer from what is known as "retrogradation" that is, the foreign matter which was not entirely eliminated upon treatment reacts with the mono calcium phosphate present to form phosphorated compounds of iron and aluminum that are insoluble in water, thereby diminishing the available phorphorus content that might be assimilated by the soil. This loss is much more serious in soils of high iron and aluminum content.
SUMMARY OF THE INVENTION
One object of this invention is to provide a new process for the solubilization of phosphate rock, such as apatites and phosphorites. More particularly, this invention provides a short time (1/2-3 hours) relatively low temperature--(50°-130° C.) solubilization process for phosphate rock which contains high proportions of foreign matter or of low phosphorus content rock, i.e., containing 10% to 25% P 2 O 5 , the rest being foreign matter, to provide:
(a) a slow release NP fertilizer (nitrogen-phosphorus);
(b) highly concentrated phosphoric acid and MAP (monoammonium phosphate); and
(c) DAP (diammonium phosphate).
DESCRIPTION OF PREFERRED EMBODIMENTS
The process of the present invention also has the advantage of there being no problems with the formation of colloidal solutions or of insoluble phosphorus compounds precipitating during storage as happens with known processes. The efficiency of phosphate fertilization is known to be much affected when soils are acid. In soils where the pH is less than 5.5, much phosphorus is lost since a high rate of acidity helps to wash out aluminum and iron compounds which lead to the appearance of insoluble phosphorus compounds within soil solutions. Therefore, for such soils, fertilizers of low water-solubility and slow citric-soluble phosphate (i.e., dissolving slowly in citric acid) fertilizers are recommended.
The process according to the present invention provides a slow release fertilizer which needs no after treatment, such as purifying, filtering, etc., which can be used directly as a fertilizer for acid soils of high aluminum and iron content, the NP rate of which lies in between 8-24 and 10-22 (which, of course, depends on the amount of solid acid ammonium sulphate initially used) KCl may be added thereto, if desired, after the initial attack, so as to thus arrive at the desired NPK rate.
The P 2 O 5 content of the fertilizer of the present invention is gradually released in the soil since 20% of it is water-soluble, 40% is soluble in a neutral citrate solution and the remainder in the state of octacalcium phosphate (OCP)--is slowly released in acid soils. Hence, when first applied, the nutrient NP substances are released in the ratio 1:2, while residual phosphorus is released over a period of time.
In the initial stage of release the growth of soil bacteria, which help in the assimilation of phosphorus by plants, paves the way for the later stages of OCP assimilation.
The lack of F-ions and/or the presence of Mg 2+ ions prevents the OCP from becoming insoluble to hydroxiapatite or fluorapatite.
The nitrate compounds held in the mixture are of the slow release kind. The double salt 5CaSO 4 (NH 4 ) 2 .H 2 O when in contact with water is broken down into CaSO 4 .2H 2 O and (NH 2 )SO 4 at a rate which depends on the temperature and on the flow of water.
In order to secure the slow release NP type fertilizer of this invention, phosphate rock is reacted with solid acid ammonium sulphate, at an amount, by weight, of 0.4 to 0.7 parts of such ammonium salt to one part of phosphatic rock at a temperature in the range of 50° to 130° C. in the presence of sufficient water to ensure a moisture content of at least 16% (and maximum 100%).
The product of this reaction is an easily handleable powdery fertilizer that has an extremely low fluourine content, its composition being principally more than 50% of DAP (diammonium phosphate) and octacalcium phosphate Ca 8 H 2 (PO 4 ) 6 ×H 2 O. During reaction more than 95% of the fluorine content is given off as HF and/or SiF 4 vapor.
Another embodiment of this invention relates to a process for obtaining highly concentrated phosphoric acid and/or an NP fertilizer which is completely soluble in water without any fine crystals of calcium sulphate being formed, this being one of the chief drawbacks of prior art to water-type systems. Per this embodiment, the calcium sulphate is precipitated as crystals that are easily filtered out. The process of this embodiment involves solubilizing the phosphate rock with acid ammonium sulphate in an amount by weight of 0.4 to 0.7 parts of solid acid ammonium sulphate to one part of phosphatic rock in the presence of water in an amount by weight in the range of 0.5 to 4 parts of water to one part of phosphatic rock at a temperature of from 50° to 110° C. for a reaction time of 10-180 minutes; followed by the addition of concentrated sulphuric acid in an amount by weight of 0.15 to 0.50 parts of concentrated 96% to 100% sulphuric acid to one part of phosphatic rock; the temperature in this latter step being held at 30+ to 80° C. for a period of no longer than one hour and minimum five minutes.
To the product obtained, which is a mixture of CaSO 4 MAP and H 3 PO 4 , preheated to 50°-70° C. ethyl alcohol is added in an amount by weight of 2 to 6 parts of alcohol to one part of phosphatic rock, the MAP and H 3 PO 4 being easily solubilized while calcium sulphate and other foreign material are precipitated as crystals that are easily filtered out.
If desired, the resulting alcohol solution containing phosphoric acid and MAP may be distilled to obtain highly concentrated phosphoric acid and MAP. It is preferred to treat such an alcohol solution with ammonia (NH 3 ) at a temperature of 25° to 60° C. to provide a fertilizer which may be easily dissolved in water and which is mainly made up of DAP (more than 50%) and a smaller proportion of ammonium sulphate (less than 49%), the amount of the latter depending on the quantity of excess acid ammonium sulphate employed in the reaction. It is possible to work with until 49% of excess.
Some examples of the invention are next given which describe, but do not limit it.
EXAMPLE I
15 g of concentrate from Araxa, the composition of which was: Fe 2 O 3 -3.76%, CaO-56.46%, SrO-0.58%, TiO 2 -1.12%, BaO-0.2%, P 2 O 5 -36.4%, SiO 2 -0.35%, Al 2 O 3 -0.97%, CO 2 -1.17%, MgO-0.14%, Na 2 O-0.27%, F-1.94%, P 2 O 5 , soluble in neutral citrate, 0.71% and P 2 O 5 soluble in citric acid-3.6%, were mixed with 7.8 g of NH 4 HSO 4 and 20 ml of H 2 O. The temperature was then raised to 100° C. and, after reacting for 1/2 hour, the ground product had the following composition: F-0.05%, P 2 O 5 -total 22.2%, P 2 O 5 soluble in H 2 O-5.3%, P 2 O 5 soluble in neutral citrate-8.8%, N-4.2%.
EXAMPLE II
15 g of VALEP concentrate, the composition of which was: Fe 2 O 3 -3.67%, CaO-49.94%, SrO-0.51%, TiO 2 -1.89%, K 2 O-0.20%, P 2 O 5 -34.95%, SiO 2 -1.93%, Al 2 O 3 -1.37%, CO 2 -0.84%, MgO-0.23%, Na 2 O-0.09%, F-1.33%, P 2 O 5 soluble in neutral citrate-0.57%, P 2 O 5 -soluble in citric acid-4.7%, were mixed with 7.5 g of NH 4 HSO 4 and 20 ml of H 2 O. The temperature was then raised to 100° C. and, after 1/2 an hour of reacting, the ground powdery product had the following composition: F-0.04%, P 2 O 5 (total)-21.3%, P 2 O 5 soluble in water-5.3%, P 2 O 5 soluble in neutral citrate-8.13%, N-4.3%.
EXAMPLE III
13 g of rock concentrate from Patos de Minas, the composition of which was: Fe 2 O 3 -3.19%, CaO-31.9%, SrO-0.22%, TiO 2 -0.31%, BaO-0.01%, P 2 O 5 -26%, SiO 2 -10.2%, Al 2 O 3 -6.8%, CO 2 -0.86%, MgO-0.04%, Na 2 O-0.06% and F-1.81%, were mixed with 7 mg of NH 4 HSO 4 and 20 ml of water. Temperature of mass being reacted was raised to 80° C. and after 150 minutes 4 g of concentrated H 2 SO 4 were added. After 30 minutes 80 ml of commercial ethyl alcohol (95%) were added to the mass being reacted. The suspension thus obtained was then filtered and the resulting precipitate was over-dried for 1 hour, after which it weighed 17.0 g and its P 2 O 5 content, non-soluble in neutral ammonium citrate, was 0.60%. The alcohol filtrate was neutralized with anhydrous ammonia where upon a precipitate was derived; the weight of which was 7.28 g, containing 41.76% of P 2 O 5 and 20.43% of N.
EXAMPLE IV
13 g of concentrate from Patos de Minas, the composition of which was the same as that in Example III, were mixed with 6 g of NH 4 HSO 4 and 20 ml of H 2 O. The temperature was then raised to 80° C. and, after 150 minutes, 4 g of concentrated H 2 SO 4 was added to the mass under reaction. Thirty minues after adding the H 2 SO 4 the reacted mass was treated with 80 ml of commercial ethyl alcohol (95%), the suspension filtered and after being left 1 hour at 80° C. in the over, its precipitate weighed 17.2 g and contained 0.7 g of P 2 O 5 , insoluble in ammonium citrate. The alcohol filtrate, after being neutralized with anyhydrous ammonia, yielded a precipitate which was found to weight 6.74 and to contain 44.53% of P 2 O 5 and 20.41% of N.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | A rapid, low temperature process for solubilizing phosphate rocks having high content of foreign matter or a low phosphorus content to obtain: (a) a slow release fertilizer of the NP type; (b) phosphoric acid of high concentration plus MAP; and (c) DAP. | 2 |
FIELD OF THE INVENTION
The present invention relates to the regulation or management of supply of electric power to load sites such as office buildings, hospitals, factories and the like which require comparatively great amounts of electric energy for load systems performing such functions as heating, cooling, or motor operation.
BACKGROUND OF THE INVENTION
Modern electric utility companies are confronted with various economic, regulatory, and environmentally related pressures which complicate, and sometimes prevent, construction of more generating capacity in response to market or service territory growth. As a consequence, although such companies usually give considerable attention to programs for energy conservation so as to moderate demand and thereby offset need for increased generating capacity, thought is currently being given by utilities to various strategies or techniques for managing or regulating customer demand for electric energy. The objective of such strategies from the utility point of view is to moderate the peaks and valleys of fluctuations in electric energy use over a given time frame such as a twenty-four hour day, and thereby smooth out the demand level over such a time period. This enables generating capacity already in place to be used most efficiently.
Electric energy users in turn have economic incentives to minimize the cost of their energy demands. Attention has therefore been focused from both supply side and demand side on efforts to achieve both reduced fluctuations in demand required to be met by the supplier, and derivation from such reduced fluctuations of lower costs for the user.
Prior art demand side management efforts on the part of utilities have involved such techniques as time-of-use pricing, in which prices are lowered to encourage filling of demand valleys and raised to moderate customer demand at peak hours, and automated shut-off of selected customer equipment such as water heaters during peak demand hours. Temporary shedding of loads in a rolling fashion in a given market or service territory is another known technique for moderating peak demand.
Unfortunately, in the aforementioned prior art systems, the user is required to provide certain startup information. For example, upon initial installation, the user is expected to provide the building design load and building use schedules, startup values for cooling load profile, noncooling electric load profile, and ambient temperature profile. Also, the user must provide maximum ton-hours of storage compacity, maximum chiller cooling rate, and maximum storage discharge rate in tons.
Such prior art techniques have lacked the sophistication required for timely consideration of all significant user-related parameters such as prospective next-day heating or cooling requirements or machine run time. They also lack the ability to respond promptly to changes in significant supplier-related factors such as variations in generating costs. Moreover, such prior art techniques rely on the user to provide a great number of initial parameters and design characteristics, which may or may not be reliable and are certainly inconvenient for the user to enter into the system periodically.
It would be advantageous and is, in fact, one of the objects of the present invention, to provide a dynamic adaptive energy scheduling system that will allow variations in parameters, transparent to the user. In the course of operating the present system of the invention, certain parameters are obtained, but need not be expressly entered into the system by the operator.
Prior art systems may also require a user to specifically provide the high and low ambient temperatures predicted by the National Weather Service for the next day. Once again, the use of a non-automated system for providing this information and the lack of updating such information has resulted in a serious impediment to the use of such systems. The fact is, that few operators take the time necessary to input this information on a daily basis and, even when they do, the information can become outdated rapidly as weather conditions change during the day. Thus, it would be advantageous to provide an energy scheduling system that calculates and recalculates predictive weather information on the basis of ongoing, changing data acquired by the system automatically and periodically.
SUMMARY OF THE INVENTION
Accordingly, the principal object of the present invention is to provide scheduling means for regulating the charging of energy into storage means in accordance with information relating to a variety of factors including predicted load demand, present level of energy already stored in the storage means, and periodically updated and refreshed information as to prospective temperature predictions and supplier prices.
Another object of the present invention is to provide improved means for managing the supply of electric energy to a load site or load system based on hourly utility-supplied pricing structures in a manner to ensure the user adequate supply without interruption and at attractive cost levels, and to ensure the supplier desirable moderation of demand fluctuations.
Another object is to provide such an energy scheduling system which involves means for the temporary storage of energy, at or near the site of the user, and which is capable of being pre-charged at optimally low cost to the user in anticipation of subsequent user demand.
Still another object is to provide an energy storage scheduling system of the foregoing character wherein the user-adjacent energy storage system may be of the primary energy storage type (i.e., capable of storing electric energy itself as by means of batteries or capacitors or the like), or may be of a type for storing thermal or potential energy.
Another object is to provide such an energy scheduling system wherein the storage means may be sized for storage of only a fraction of the load system total demand in a given demand cycle period such as a consecutive twenty-four hour daily period and wherein much of the stored energy is used and relatively little is wasted.
In accordance with the present invention, there is provided an energy utilizing load system having energy demands which vary and whose total demand for energy is satisfied by input of energy directly from an electric energy supply and input of energy released from an energy storage system, previously charged from the electric energy supply.
The energy storage scheduler of this invention schedules the timing and extent of charging a storage means from the electric energy supply. The energy storage scheduler has charge level means for receiving information representative of the level of charge of the storage means. A programmed measuring and refining mechanism is provided to quantify the load profile of the energy utilizing load system. A timer is connected to the energy storage scheduler to provide information representative of the ongoing time within the current cycle period. A price processor is connected to the energy storage scheduler for receiving and processing information representative of prospective time-varying prices of electric energy from the supply. Finally, a mechanism is provided to calculate, from the information available from the charge level means, the programmed measuring and refining mechanism, the timer and the price processor, optimal timing for charging the storage means to predetermined storage levels to achieve a minimal cost supply of the aggregate energy demands of the load system.
BRIEF DESCRIPTION OF THE FIGURES
These and other objects of the invention will become more readily apparent from a consideration of the following description together with the accompanying drawings, wherein:
FIG. 1 is a diagrammatic and schematic view of an electric energy supply system including structures and schedulers constructed and arranged in accordance with the present invention;
FIG. 2 is a block diagram of a scheduler and associated elements of the load system shown in FIG. 1; and
FIGS. 3a-3e comprise a flow chart of scheduler operations.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The diagram of FIG. 1 depicts an electric utility 2 having an electric energy supply 4 for serving the demands of a load system 6. Electric utility 2 includes load monitoring equipment 3 and typically a plurality of power substations 5 having their own load monitoring equipment 5a. A utility load control center 7 is connected to all load monitoring devices 3, 5a for monitoring the aggregate utility load and for influencing consumer load through interruption of power or through pricing.
The load system 6 may include storage apparatus 6a, which forms no part of the present invention. Storage apparatus 6a is disposed in each of the structures 6b being provided with energy. The load system 6 may consist of one or more pieces of electric energy utilizing apparatus, not shown, such as, for example, heating equipment, cooling equipment, factory machinery drive motors, or electric motors for other applications.
In the contemplation of the present invention, the load system 6 is normally of such a nature as to have an aggregate demand for electric energy which varies in a periodic or cyclical fashion in a given time frame such as a twenty-four hour day. If the load system is largely cooling (HVAC) equipment for comfort conditioning of office personnel work spaces, it will be appreciated that the demand for energy for HVAC is likely to be greatest during that portion of the twenty-four hour day when the office personnel are about to arrive or are present. Furthermore, varying weather conditions drive heating and cooling loads directly. Consequently the energy demand of the cooling equipment will be likely to vary day by day.
An energy storage scheduler 8 is provided to schedule storage of energy by receiving information from various sources as described hereinbelow and calculating appropriate values representative of decisions to be used by the storage apparatus 6a.
Referring now also to FIG. 2, there is shown a block diagram of the scheduler 8 (FIG. 1) and related components in the energy scheduling system. For purposes of brevity, identical components are identified throughout the figures with identical reference numerals.
Electric energy flows from power utility 2 to the structures 6b (FIG. 1) which contain apparatus shown generally as reference numeral 6a (FIG. 1). This apparatus comprises three components: plant equipment 9 for converting electrical energy into thermal energy including cooling energy; energy storage 10 which stores energy for future use; and equipment controls 11 for dividing energy between storage 10 and load 6, controlling plant operations, etc.
Connected to equipment controls 11 is the energy storage scheduler 8 which provides a supervisory function to the equipment controls 11. For example, signals may be generated by scheduler 8 which are applied to equipment controls 11. The information from scheduler 8 may instruct equipment controls 11 to charge storage device 10 at a specified time. It is the equipment controls 11, however, that actually initiates such charging operation of the storage devices 10. Without the scheduler 8 providing supervisory scheduling information to the equipment controls 11, equipment controls would usually charge the storage devices 10 at a predetermined time regardless of the cost of doing so. Thus, scheduler 8 provides a valuable function in providing intelligence to the system so that the cost of charging the storage devices 10 is minimized.
Scheduler 8 is also adapted, as hereinbelow described in greater detail, to receive feedback information from components such as the storage devices 10 and the equipment controls 11. Such information is used by scheduler 8 to update its scheduling. In addition, scheduler 8 is adapted to receive data from external sources representative of outdoor temperature, pricing information or certain other information that would override the normal operation of the system, such as special events, additional load requirements, storage devices and the like. In this way, the system can adapt to new situations dynamically and scheduler 8 can reflect ongoing changes in the system and store such historical data for future reference.
Scheduler 8 is also adapted to receive overriding information from an operator, in certain unforeseeable emergencies. Scheduler 8 can also receive utility override information which may occur during high utility demand periods. In other words, scheduler 8 can be an integral component in a load-shedding operation, when required. Moreover, scheduler 8 is also adapted to receive information from an energy management control system (EMCS) which may be part of a building complex.
Referring now to FIG. 3, there is shown a flow chart of scheduler 8 operations in accordance with the present invention.
During system initialization, step 101, the following information is entered, either manually by the operator or automatically:
a) present date and time;
b) energy storage system charge input rate;
c) storage system type(s) being controlled (menu choices);
d) input port configuration information by channel:
Temperature Inputs
Runtime Inputs
Utility Control Signals
EMCS Control Signals
Manual Override Signals
State of Charge Senor Type;
e) output control port configuration information by channel:
Heating System Charge Enable
Cooling System Charge Enable
Auxiliary HVAC System Charge Enable
Other Energy System Charge Enable;
f) channel multipliers and off-sets;
g) pricing format (menu);
h) source of pricing and temperature prediction data (e.g., local keyboard, modem, radio frequency link);
i) data format information (menu); and
j) full load (worst case) conditions.
A safety, step 102, can be any contact closure input to the energy storage scheduling system. Examples of a safety input are heat and smoke alarms.
A demand limit, step 104, is a contact closure input from any source, such as an energy management system, which is used to shed connected electric loads in an effort to curtail usage and maintain a maximum energy demand. This is true for any energy source. When the energy storage scheduling system receives a contact closure on the demand limit input port, step 104, it immediately terminates excess energy usage step 103. Thus, if the system is charging the energy storage medium, that activity is suspended until the demand limit signal has been released.
A utility radio control override signal, step 105, is any contact closure input to the energy storage scheduling system generated as a result of any utility control system signal. The control signal is typically intended to terminate charging of the energy storage medium.
The call for heat signal, step 106, is indicative of building heating load.
The call for cooling signal, step 110, is indicative of building cooling load.
Auxiliary HVAC is enabled, step 119, when there is a continuous call for heating or cooling and conditioned space temperature is a) falling in heating mode, or b) rising in cooling mode.
The current storage inventory, step 125, is derived from an energy balance maintained on the storage system. Measured storage output to load and charge operating time, along with charging capacity, are all used to maintain the energy balance.
Outdoor air prediction, step 126, is refined by a ratio adjustment of measured temperature and predicted temperature.
Adjustments to the predicted load, step 127, are made based on the ratio of measured temperature to predicted temperature and the difference between previous predictions and actual load.
Adjustments to the hourly estimated stored energy inventory, step 128, are based on actual last hour usage and new predicted building load.
Rate-of-charge may not match input capacity for certain types of systems (e.g., simultaneous charge and discharge). The time to reach a desired storage inventory while meeting the load is determined, step 129, by the ratio of required storage to system input capacity minus load.
The next day's hourly load profile is predicted, step 132, by starting with the last similar day as the base condition. During initialization, full load prediction is assumed. The total load is distributed over the hourly load shape, making a ratio adjustment based on predicted and actual weather data. An uncertainty factor is added to the hourly loads.
Charge periods are planned, step 133, so that the lowest cost hour is used to make up the storage deficit before storage is depleted.
Rate-of-charge or charge time is reduced, step 134, so that the storage charge input meets only the predicted storage deficit.
The planned charging schedule is refined, step 136, based on current inventory, next hour predicted load and rate-of-charge.
The purpose of energy storage scheduler 8 is to achieve the goals of a) smoothing demand from load system 6 on supply 4 (FIG. 1) for the benefit of the supplying utility, and b) minimizing the total cost of energy supplied to load system 6. Scheduler 8 is programmed to apprise equipment controls 11 to begin charging storage devices 10 and/or to provide energy to the load 6, based on inputs to scheduler 8 of information regarding a number of scheduling factors. Such factors include the current level or quantity of energy already stored in storage means 10 and currently available for release to load system 6. This factor may be continuously monitored directly from storage means 10.
Another significant control factor is information predictive of energy demand of load system 6 during each hour, fractional hour or other time increment. For example, where the load system 6 is involved with heating, cooling, or other personal comfort-related functions, information predictive of weather conditions anticipated to prevail during the next time period is supplied to scheduler 8 by means of a conventional outside temperature sensor, not shown.
Time information continuously providing the current time is supplied to scheduler 8 so that time-related decisions of the scheduler 8 can be time-referenced.
Finally, it is a particular feature of the present invention that the scheduler 8 is supplied with information, periodically, as to the expected or predicted hour-by-hour prices to be charged by the utility 2 during each hour, or selected time increment.
With the above-described inputs it will be appreciated that the scheduler 8 serves as a calculator or computer for determining how best to supply the predicted demands of load system 6 at minimum cost to the user. The utility 2, by adjusting or designing its time-of-use and/or real-time prices, can influence scheduler 8 decisions and thereby smooth demand on its supply system through valley filling and peak shaving. Scheduler 8 provides sophisticated and timely regulation of energy flow from supply 4, as influenced for benefit of the utility by its pricing structure, and for benefit of the user by minimum cost goals. Moreover, the scheduler 8 enables full advantage to be taken of price changes from the utility, which may occur hourly or even more frequently in real time as conditions within the utility generating system vary.
Charge decisions of the scheduler 8 will also require taking into account the capacity limits of storage means 10 relative to total anticipated demand of load system 6, and the desirability of not wasting stored charge, as might be possible, for example, when thermal energy is stored, which gradually dissipates and degrades over time if not used.
Scheduler 8 may be a commercially available computer, such as an IBM PC, or microcontroller programmed to receive the inputs described heretofore, and to make energy storage decisions at intervals of any desired length during the cycle period of load system 6.
From the foregoing description and the accompanying drawing, it will be apparent that the present invention provides, for use with energy storage means as described, improved means for managing and regulating energy demand to achieve beneficial moderation of demand peaks and valleys while responding promptly to continually updated and refreshed pricing information so as to optimize user cost savings. The invention is not limited to the precise embodiment shown in the illustrative drawing and various modifications and changes may, it will be recognized, be made by those skilled in the art without departing from the scope and spirit of the invention, as defined by the appended claims. | The present invention features an energy storage scheduler that schedules the timing and extent of charging a storage device from the electric energy supply. The energy storage scheduler has a charge level device for receiving information representative of the level of charge of the storage device. A programmed measuring and refining mechanism is provided to quantify the load profile of the energy utilizing load system. A timer is connected to the energy storage scheduler to provide information representative of the ongoing time within the current cycle period. A price processor is connected to the energy storage scheduler for receiving and processing information representative of prospective time-varying prices of electric energy from the supply. Finally, a mechanism is provided to calculate, from the information available from the charge level device, the programmed measuring and refining mechanism, the timer and the price processor, optimal timing for charging the storage device to predetermined storage levels to achieve a minimal cost supply of the aggregate energy demands of the load system. | 5 |
[0001] The title of this invention is Artery and Vein Coupling Tie String (A/V Coupling Tie String). The name of the inventor is Thomas Aikens, a citizen of the United States of America, residing at 3106 E. Lake Avenue, Tampa, Fla. 33610.
[0002] The tie strings we used with the arteries/veins coupling system of human remains after the embalming process. After the process of arterial injection of chemicals and draining of fluids by the embalmer, the tie strings are tied around both ring ends of the arterial/vein coupling. The tie strings are round with self locking teeth, adjustable throughout its entire length. The tie strings are made from one of the polymers; nylon, polycarbonate, polyethylene, and poly vinyl chloride. The tie strings are 8.00″, 9.00″, 16.00″, 24.00″ in length; 0.140″, 0.135″, 0.190″, 0.320″ in width.
CROSS REFERENCE TO RELATED APPLICATIONS
[0003] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH DEVELOPMENT
[0004] Not Applicable
REFERENCE TO MICROFICHE APPENDIX
[0005] Not Applicable
BACKGROUND OF THE INVENTION
[0006] The field of use is the funeral industry, specifically in the embalming process of human remains. The subject matter of the claimed invention is to secure the arteries and veins coupling and vessels together after the process of embalming human remains. Using this invention will aide in solving the problem of leakage encountered by the embalmer. The only possible known related mechanism is in the construction field used for wrapping materials, flat tie strap.
BRIEF SUMMARY OF THE INVENTION
[0007] The general idea of the claimed invention is to aide the arteries/veins coupling after the embalming process. Ensuring proper connection of the vessels to the arteries/veins coupling. This will solve the problem of the vessels slipping from the arteries and veins coupling.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0008] Not Applicable
DETAILED DESCRIPTION OF THE INVENTION
[0009] The process of making the tie string is comprised of first a die of the tie string. Before a die is built, complete drawings and specifications of the tie string are required to guide the die maker. Each component must be measured and then fitted together, before testing for proper function. The die is a tool used in conjunction with an injection molding machine. The injection molding machine processes polymers of the thermoplastic material which is fed into a hopper, that is attached on the top of the machine and emerges as hot melt at the die. This process consists of heating and homogenizing plastic granules or polymers in a cylinder until there is sufficient fluid to allow for pressure injection into a relatively cold mold where they solidify and take the shape of the mold cavity or die. In the process of embalming, which is chemically treating the dead human body to reduce the presence and growth of microorganisms, to retard organic decomposition and to restore life-like appearance. The arteries and veins are used for this process by making an incision in both vessels and chemically treating the human remains. After this technique the A/V Coupling would be inserted in both artery and vein with the tie strings on both ends to prevent leakage of fluids and pressure build up in the body, which allows equal pressure to all parts of the human remains, this will keep swelling from occurring. There is no other product on the market in the funeral industry to compare with the tie string. The entire tie string is made from polymer. Polymer is a chemical reaction in which a number of similar small molecules is called polymerization, and the macromolecular product is a polymer.
[0010] In the human body, blood is contained within many tube like structures, the arteries and veins which compose the vascular system. The blood is forced to flow continuously to all parts of the body by the powerful pumping action of the heart. After death, the heart no longer can perform this duty, the use of a embalming machine is used. The embalming machine acts as the heart, which creates pressure in the body that force the blood out of the arteries and veins. An embalming instrument is placed in both artery and vein to remove blood from the dead human remains. The removal of the blood from the arteries and veins, the embalmer must make an incision in both arteries and veins. The arteries/vein coupling will come in place at this time and be inserted in both vessels with the guide director. Once the arteries and veins coupling are inserted, then the tie strings are placed around both ring ends of the coupling. | The tie string is new to the field of embalming because there is no device used in the field of the funeral industry with self locking polymer teeth. There are linen, nylon, polyester, and cotton thread, non locking. | 0 |
FIELD OF THE INVENTION
The invention relates to a baker's oven and in particular to the operation of the oven.
BACKGROUND OF THE INVENTION
A conventional baker's oven comprises a number of stacked oven compartments with individual oven doors at the front. Each level of the oven includes two side by side compartments, which each have a fixed shelf onto which baking trays or bread pans or a like can be loaded.
The oven compartments are heated by electric heating elements mounted bottom and top of each compartment. The heating elements are formed as single heating units comprising a number of parallel arms connected in series by U-shaped elements. The parallel arms extend from the oven door to the rear of the compartment and are spaced across the width of the oven.
The top and bottom heating elements can be separately controlled to vary the heat distribution within the oven. For certain types of baked goods, it is advantageous to supply the heat predominantly from the bottom of the oven. The bottom heating elements of conventional baker's ovens are usually more or less uniformly distributed over the floor of the oven to provide a uniform distribution of heat within the oven. According to conventional baking practice, it is important that a constant temperature is maintained throughout the baking cycle, thus preheating the oven, or allowing the oven to cool prior to loading with product is important. Typically the oven temperature must be kept within 10° C. of an ideal temperature.
It is known to use a timer to activate the oven prior to the arrival of the baker at the start of the day, so that the oven is preheated when the baker arrives. While the use of a timer effectively presents an oven at a predetermined temperature at a time set many hours earlier, there are risks (e.g., of fire) associated with activating unattended ovens. Commercially available Multi-deck, Setter ovens, and other such ovens with multiple baking chambers within one chassis, may be capable of baking many different products at the same time. However, it is commercially accepted that these ovens need to be pre-heated to, or above, recipe temperature before loading each product. As there is no fan assistance in most conventional ovens, the heat is typically difficult to control, and the baker must often be familiar with each oven's characteristics to achieve acceptable results.
Different bakery products require different baking temperatures. Therefore the baker's production schedule is complicated, and the oven utilization is reduced by having to pre-heat/pre-cool an oven prior to baking. The production schedule must be changed so that the oven temperature closely matches the requirements of the next product to be loaded. In busy bakeries, there is often the need to break the usual production cycle (due to rejected product, unexpected orders etc.) and there is also the issue of inexperienced staff needing to run ovens at short notice. Even for the most experienced operator, the issues involved in obtaining the most efficient production schedule are often at odds with what the store's customer's demand for fresh full variety of product.
A particular problem with controlling oven temperature is “heat over-run”. Heat over-run stems from the thermal inertia of the heating system. Typically the heating elements are much hotter than the air in the oven. Heat is thereby transferred from the elements to the air and is in turn transferred to the bakery product in the oven. Heat over-run occurs after the oven is unloaded and the bakery product is removed. After the bakery products are removed, even if the heating elements are deactivated, heat stored within the elements is transferred to the air within the empty oven. This results in a very hot oven. This heat is not only wasted but results in considerable inefficiency in that the oven may well be too hot for the next batch of products to be loaded, meaning that the oven must then be precooled for the next batch. One approach to the issue is to gradually reduce the power to the heating elements as the oven air temperature approaches a required baking temperature. This means that the elements are not as hot as they might be when the oven is unloaded.
Objects of the present invention include to reduce oven preheating/precooling requirements or at least provide alternatives to existing arrangements in the marketplace.
SUMMARY OF THE INVENTION
According to the invention, there is provided a baker's oven including:
supporting means for supporting one or more baking trays; heating means arranged to underlie the baking trays to provide a substantial proportion of the heat to the baking trays than to other portions of the oven; a temperature sensor for providing a signal indicative of oven temperature; an interface adapted to receive information from a baker indicative of a bake program and information indicative of products being loaded into the oven; control means operatively connected to the heating means, the temperature sensor and the interface; and the control means being adapted to deactivate the heating means after a first predetermined portion of a fixed baking time in response to the oven temperature reaching a trip temperature.
“Baking time” as used herein refers to the baking time experienced by the product. Typically the baking time commences with product being loaded into the oven and finishes with the issuance of a signal from an indicator means indicative of the end of the cycle (in response to which a baker should remove the product from the oven). The product could be retarded or proofed in a cold oven for a period of time (e.g., overnight). The baking time would then commence with the activation of the heating means.
The information indicative of a bake program might simply be the required baking time and a desired temperature (e.g., the trip temperature). Alternatively, the information might simply be an indicator of product type, the control means being configured to calculate the trip temperature and baking time based on the product type.
The control means may be adapted to deactivate the heating means after a second predetermined portion of the baking time independently of the oven temperature.
Preferably the control means is configured to thermostatically control the heating means. For example, the heating means may be thermostatically controlled to maintain the trip point temperature.
The first predetermined portion is preferably between 80% and 90%, and most preferably about 85%, of the baking time. The second predetermined portion is preferably about 95% of the baking time.
The trip temperature may be preselected to be about 10 degrees below a high set temperature, the high set temperature being the highest maximum temperature the oven should reach at any time. This temperature is determined by trial and error with the highset temperature being the highest baking temperature of the oven to yield acceptable product.
According to another aspect of the invention there is provided a method of operating the baking oven including a heating means arranged to underlie baking trays whereby a substantial proportion of the heat is provided to the baking trays, the method including the steps of heating the heating means according to a bake program indicative of products loaded into the oven, and deactivating the heating means after a first predetermined portion of a fixed baking time in response to the oven reaching a trip temperature.
The heating means and the supporting means are preferably relatively moveable to reduce the incidence of localized burning of product on the baking trays proximal the heating means.
The supporting means may include a carousel rotatable about a vertical axis. The interior of the oven is preferably substantially free of high thermal inertia objects, such as bulk ceramic material and plate metal fittings, to minimize thermal inertia of the oven interior and thereby improve baking conditions. This ensures that a large proportion and preferably substantially all of the heat supplied by the heating elements arranged according to the invention is supplied directly to productively produce product rather than heating objects, which store and radiate heat.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional side view of a five level rotary baker's oven in accordance with an embodiment of the present invention;
FIG. 2 is a sectional plan view showing one level of a previously disclosed oven; and
FIG. 3 is a sectional plan view of one side of one of the levels of the oven of FIG. 1 showing the heating elements and the baking trays.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been discovered that by concentrating the active portions of the heating elements more directly under the baking trays the quality of baked goods and the operation of the baking oven can be improved. This has been found to be associated with supplying the heat more directly to the product.
According to an aspect of the invention not expressly claimed herein, there is provided a baking oven having heating elements arranged to underlie baking trays to provide a substantial proportion and preferably substantially all of the heat to an active region under the baking trays than to an inactive region positioned outwardly of the active region.
The oven chamber preferably includes heating elements extending from a wall of the oven into the active region, each element having an inactive portion and an active portion, the inactive portion extending from the wall to the active portion, which extends within the active region for more directly heating the underside of the baking trays.
In an advantageous arrangement, the oven includes a rotatable turntable for supporting the baking trays. In this instance the active region may be defined by an outer most periphery of the baking tray as it is rotated on the turntable. Alternatively, the active portions of the elements may lie within a region defined by an inner most portion of the outer periphery of the baking trays as they are rotated on the turntable. Preferably the baking trays define a rectangle centered on an axis of rotation of the carousel and the active region boundary is defined as being located between, and most preferably half way between, a circle defined by rotation of an outer most corner of the rectangle and a circle defined by rotation of the nearest approach of an edge of the rectangle about the axis.
Preferably the heating elements are arranged to provide more than 2 times, preferably 2.5 to 3.5, and most preferably 2.9 to 3.1, times greater power density to the active region than to the inactive region.
Preferably the heating elements are relatively narrow thereby allowing the heating elements to be more densely concentrated within the active region. Each heating element may include two elongate heating element portions, a steam generation chamber positioned intermediate and operably connected to the elongate heating element portions and having at least one steam outlet.
Referring to FIGS. 1 and 2 , the baker's oven is a rotary oven 10 similar to the type sold under the registered trade mark “ROTEL”. In the embodiment illustrated, the oven has five levels with two oven compartments 11 on each level. A drive motor 12 (not shown) is operably connected to a pair of vertical shafts 13 on which are mounted turntables 14 , which may incorporate optional ceramic “tiles” 15 on which the baking trays (not shown) are cooked. Each oven compartment 11 has an oven door 16 operably openable and closable by a handle 17 .
Each oven compartment 11 has top heating elements 18 mounted to the underside of the top wall 19 of the oven compartment 11 . As shown in more detail in FIG. 3 , each oven compartment 11 has a pair of substantially U-shaped inner heating elements 20 mounted on the bottom wall 19 a . The operation of the heating elements 20 is controlled by a computerized control system (not shown).
By selectively energizing the upper heating element 18 and the lower heating element 20 it is possible to control:
1. The air temperature within the oven chamber,
2. The heat rising directly from the lower heating element 20 to the bottom of the turntable 14 and thus the baking trays 30 , and
3. The heat radiating from the upper heating elements 18 .
For example by supplying more electrical power to the lower element 20 , it is possible to supply more heat to the bottom of the turntable 14 and thus baking trays 30 . This could be used to produce, for example, a bread having more bottom crust and a darker baked color on top.
It has been found that the position of the heating elements has a large bearing on the quality of the baked product. This is thought to be related to the control over the application of heat to the lower surfaces of turntable 14 and baking trays 30 . By concentrating the heating elements under the baking trays, it is possible to provide a more concentrated heat to the underside of the turntable 14 and baking trays 30 and thereby have greater control over the above listed variables. The result is a baking oven, which can be used to produce an improved baked product.
FIG. 3 shows a cross sectional plan view of one side of the oven of FIG. 1 . It shows a potential layout of the heating elements 20 and the relative positioning of the baking trays 30 when in use. The turntable 14 is omitted from this view for clarity. As illustrated the heating elements 20 are relatively narrow elongate members. This allows the heating elements 20 to be more closely spaced and positioned under the baking trays 30 . Only three elements 20 are illustrated here for clarity although of course it is possible to use more. This concentration of heating elements differs from conventional thinking, which would have a number of widely spaced heating element portions evenly distributed across the oven floor to produce a more even distribution of heat throughout the baking chambers.
As illustrated in FIG. 2 , previously disclosed ovens have widely spaced heating elements evenly spread across the baking chamber 11 including providing heating element portions 23 close to peripheral wall 25 .
To give an idea of scale, each baking tray 30 is about 18 inches (460 mm) by about 30 inches (720 mm) and the trays are spaced by the shaft 30 , which is about 1 inch (25 mm) thick. Thus the two trays being spaced by the shaft 13 define a rectangle of about 37 inches (940 mm) by about 30 inches (720 mm). This tray size is commonly used in Victoria (a region of Australia). Elsewhere in Australia 405 mm×737 mm is a common tray size. Trays as large as 460 mm×762 mm are sometimes used.
Each heating element 20 is provided with an inactive portion 21 and an active portion 22 . The inactive portion 21 does not produce heat. The active portion 22 produces heat. The heating element extends from a wall 120 of the oven with the inactive portion 21 of the heating element providing an inactive region of the oven. The active portion 22 of the heating element extends from the inactive portion 21 into the active region of the oven beneath the baking trays 30 . The active portions have a more or less homogenous construction, but have been found to produce little or no heat along a length of 25 mm or so adjacent the inactive portions 21 .
It has been found that an improved distribution of heat within the baking chamber can be achieved by positioning the active portions 22 within the region 40 described by the outer most corner 31 of the baking trays as it is rotated about the shaft 13 . This region is herein referred to as the active region. The shorter heating element 20 is arranged so that the active portion 22 lies predominantly within a smaller active region 41 . The smaller active region 41 is defined by the nearest approach of the farther surfaces 31 of tray 30 to the shaft 13 as it is pivoted about shaft 13 . Innermost active region 42 is defined by the innermost approach of edge 32 of trays 30 as it rotates around shaft 13 . The positioning of the active portions 22 within this innermost active region 42 means that the active regions are always directly underneath the baking tray as it is rotated about shaft 13 .
The ideal location of the boundary 140 between the active region and the inactive region is calculated with respect to the nearest and furthest approaches (relative to the central axis 13 ) of the edge 31 , which correspond to the circles 40 , 41 , such that boundary 140 is halfway between circles 40 , 41 . Power densities of 0.133 W/cm 2 and 0.4 W/cm 2 in the inactive and active regions respectively have been found to be ideal.
TABLE 1
Scenario 1
Scenario 2
High oven air
Low oven air
Process
temp bake
temp bake
Oven temp before load (0 min)
230
200
Oven temp after load (0 min)
210
170
Oven temp after (10 min)
220
190
(at trip point)
Oven temp after (20 min)
220
205
(at trip point)
Oven temp at 85% of bake time
220
210
(25.5 min)
(all heating off)
Oven temp at 90% of bake time
218
212
(27 min)
Oven temp at 95% of bake time
216
216
(28.5 min)
(all heating off)
Oven temp at unload (30 min)
214
214
Oven temp after unloading (30 min)
228
228
Table 1 illustrates the operation of the oven according to a preferred form of the invention. In this example the bakery product is sandwich bread for which a baking time of 30 min and high set temp of 230° C. have been determined through trial and error on this type of oven to be sufficient to produce acceptable product. Two possible scenarios are shown. In scenario 1 the oven is initially relatively hot. Scenario 2 shows an initially cooler oven.
In both scenarios a trip point temperature of 220° C., i.e., 10° C. less than the high set temp, is determined. About 30° C. of heat is lost from the oven upon loading. The oven is then thermostatically controlled to maintain, or at least attempt to maintain the trip point temperature.
In scenario 1, starting out with a relatively hot oven, the oven cools and reaches trip point temperature 220° C. after 10 min. Thereafter the heating elements are thermostatically controlled to cycle on and off to maintain this temperature. Having reached trip point temperature, the elements are deactivated at 85% of the baking time, i.e., 25.5 minutes. Having cycled on and off between 10 and 25.5 minutes, the heating elements in this scenario are active for a total 23 minutes out of the 30 minute baking time.
In scenario 2, starting with a cooler oven, the heating elements operate continuously but the oven does not reach trip point temperature. The heating elements are deactivated at 95% of the baking time, i.e., 28.5 minutes.
In both scenarios the bread continues to bake after deactivation of the elements. Residual heat within the oven, including heat stored in the elements is thus absorbed. As a result, upon unloading, the elements are much cooler than they might otherwise be, and heat over-run is substantially reduced. In both scenarios, the heat over-run is only 14° C. (i.e., 214° C. to 228° C.) so that a like batch of bread can be immediately loaded.
Both scenarios produce satisfactory bread, indeed the product is essentially indistinguishable.
The method of operating and controlling the heating elements is preferably implemented using electronics and software incorporated into the oven.
The preferred operation of the oven is as follows:
The baker selects the product to be baked, from a menu that is presented as a product name, product category, or as a simple product code or number. These can be presented on the control panel screen as pictures, drawings, or just descriptive names or numbers. In response to the product selection, the controller 61 determines the trip temperature and baking time.
Once selected, program lock-outs that will stop the program operating are “MINIMUM LOAD TEMPERATURE” and “MAXIMUM LOAD TEMPERATURE” that may be specific to each product, or sometimes product type. A thermocouple 62 inside the oven chamber is read at regular intervals by the software, and so, for example, an oven chamber that is read as at 120 degrees C. will reject any program for products with a “MINIMUM LOAD TEMPERATURE” above 120 degrees. There may be many products that can bake and produce acceptable product from as low as 20 degrees C., ranging up to 119 degrees C., and any of these can be loaded without lock-out occurring.
Once the program product has been accepted the interface 60 will flash a message “LOAD PRODUCT”. Once loaded, the baker presses the “BAKE START” button, and the elements are thermostatically operated by power source 63 to maintain the trip temperature.
As heat is supplied directly to the product from elements on the oven floor and oven roof, it is possible to provide more or less top heat or bottom heat to the product, so as to ensure that, for example, product with a thicker bottom material than top material will have the thicker material bake at the same time by simply increasing bottom element power and reducing top element power.
The concentration of heating elements in the active region is thought to allow a more directed application of heat to the baking trays, thereby reducing product burning as a result of excessive oven temperature. The relative motion of the carousel has been found to reduce burning of products overlying the elements.
It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention. | A baker's oven 10 and a method of operating the baking oven 10 . The baking oven 10 including heating means 50 arranged to underlie baking trays 31 to provide a substantial proportion of the heat to the baking trays 31 than to other portions of the oven, a temperature sensor 62 for providing a signal indicative of oven temperature. An interface 60 is adapted to receive information from a baker indicative of a bake program and information corresponding to products being loaded into the oven. The control means 61 is operatively connected to the heating means 50 , the temperature sensor 62 and the interface 60 to receive signals corresponding to oven variables comprising the oven temperature and a fixed baking time indicative of the product. The control means 61 is adapted to deactivate the heating means 50 after a first predetermined portion of the fixed baking time has elapsed in response to the oven temperature reaching a trip temperature. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to molds in metal casting systems wherein an electromagnetic inductor serves to shape molten metal prior to the solidification thereof, and more particularly, to an adjustable mold wherein the side walls of the mold are movable so as to cast ingots of various different sizes.
Electromagnetic casting systems to which the instant invention relates includes systems for electromagnetically casting wherein molten metal is introduced at a controlled rate onto a movable bottom block located within a loop-shaped electrical inductor. The bottom block is lowered at a controlled rate with metal flow being controlled in accordance with this rate to form an ingot. The molten metal so introduced is confined laterally inside the inductor by an electromagnetic field generated by an alternating current in the inductor. The molten metal is thus formed into a shape in a horizontal plane similar to the inductor. The emerging bottom block and ingot are subjected to rapid cooling by the application of a coolant, such as water, to solidify the ingot into this shape.
In most of these type systems there is a tapered electromagnetic shield or screen located inside the inductor arranged coaxially therewith made of a non-magnetic, but electrically conductive, metal, such as stainless steel. The shield, because of its taper, serves to attenuate the magnetic field of the inductor upwardly, thereby lessening the electromagnetic forces restraining the ingot at the top as opposed to those at the lower edge of the shield. The advantages of such a shield are more fully described in U.S. Pat. No. 3,605,865 to Getselev.
As is the case in the conventional casting of rectangular ingots by the direct chill method, ingots cast by the above-noted electromagnetic casting systems typically have somewhat concave side walls. The reasons for this less than ideal configuration are discussed in detail in U.S. Pat. No. 4,216,817 to Meier which is incorporated herein by reference.
Molds for use in the electromagnetic casting systems noted above are quite costly. One of the chief reasons for the high cost of the molds is due to the critical tolerances which must be maintained when machining a mold. In addition, due to the fact that numerous ingots of various sizes are normally cast, one is required to maintain an inventory of molds of various sizes which is economically undesirable. Naturally, it would be highly desirable to provide a mold for electromagnetic casting systems wherein the side walls are readily adjustable so as to enable the casting of various sizes of ingots.
Accordingly, it is the principal object of the present invention to provide an adjustable mold for use in electromagnetic casting.
It is a particular object of the present invention to provide an adjustable mold for electromagnetic casting which allows for ingots with substantially flat side walls to be cast.
It is a further object of the present invention to provide an adjustable mold for electromagnetic casting wherein the side walls are readily adjustable.
It is a still further object of the present invention to provide an adjustable mold for electromagnetic casting which is simple in construction and economic to manufacture.
Further objects and advantages of the present invention will appear hereinbelow.
SUMMARY OF THE INVENTION
In accordance with the present invention the foregoing objects and advantages are readily obtained.
The present invention comprises an adjustable mold for use in electromagnetic casting systems which allows for ingots of various sizes to be cast in a single mold. In the preferred embodiment of the present invention, the side walls of the mold may be segmented so as to assure substantially flat side walls on the cast ingots. In accordance with the present invention, the mold is provided with a first pair of opposed, segmented, stationary side walls and a second pair of opposed adjustable end walls located substantially perpendicular to the first pair of side walls so as to define a mold cavity. In accordance with the preferred embodiment of the present invention, the adjustable walls are moved along the segmented side walls and positioned at predetermined increments along the surface thereof. Small gaps of from about 1/16" to 1/2" are provided between the side walls and the end walls to allow for easy movement of the end walls. The gaps are beneficial in that they eliminate the need for critical tolerances associated with conventional EMC molds which greatly increase the costs of manufacturing same. Once the adjustable walls are positioned, contacts are provided between the segmented and adjustable walls to insure good contact between the inductor portions of the mold and the shield portions of the mold. Failure to maintain good contact between the shield portions will result in bad ingot surface structure.
In accordance with the present invention, relatively flat side walls can be cast by electromagnetic casting in ingots of different sizes by employing a single mold configuration having adjustable end walls and segmented side walls. The mold is simple in construction and relatively inexpensive to manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of an adjustable mold for use in an electromagnetic casting system in accordance with the present invention.
FIG. 2 is sectional view taken along line 2--2 of the adjustable mold of FIG. 1.
FIG. 3 is a partial sectional view taken along line 3--3 of the adjustable mold of FIG. 1.
DETAILED DESCRIPTION
With reference to FIGS. 1 through 3, an adjustable mold 10 is illustrated having a pair of opposed, segmented side walls 12 and a pair of movable end walls 14 which together define a mold cavity 16. Gaps of from about 1/16" to 1/2" are provided between the ends on the end walls 14 and the side walls 12. End walls 14 are provided with extension portion 18 adapted to slide along the top surface of side walls 12. A spring loaded detent 20 is mounted on each extension portion 18 of end walls 14 and is adapted to be received in orifices 22 located at predetermined positions on the top surface of side walls 12 for securing the end walls 14 at desired locations along the side walls 16. With particular reference to FIG. 2, detent 20 comprises a housing 50 mounted in a cut out 52 in extension portion 18. Housing 50 has a first chamber 54 which receives pin portion 56 which has secured thereto a flange 58 against which a spring 60 abuts so as to bias pin portion 56 out of engagement with orifice 22. The housing 50 is provided on the upper portion 62 thereof with a slot 64 which receives a projection 66 secured to pin 56 to hold the pin 56 against the bias of spring 60 in orifice 22 for securing the end walls 14 in place on side walls 12.
With reference to FIG. 3 the side walls 12 of the mold 10 comprises a support frame 24 having a portion of insulating material 26 secured thereto by means of bolts 28. An induction coil 30 having a cooling channel 32 is mounted to the insulating material 26 by bolts 34. Mounted on support frame 24 by bolt 37 is an electromagnetic screen 36 which forms with induction coil 30 a gap 38 for directing a coolant stream from reservoir 40 in support frame 24 via passage 42 to the surface of the ingot being cast. The end walls 14 of the mold 10 are constructed in the same manner as the side walls.
Referring again to FIGS. 1 and 2, mounted on the back face 70 of end walls 14 proximate to side walls 12 are clamping members 72 for making electrical contact between inductors 30 and screens 36 of the side walls 12 and the corresponding inductors 30 and screens 36 of end walls 14. Each clamping member 72 comprises a housing 74 having a bore 76 provided with a plurality of bearings 78 for rotatably mounting a shaft 80. As shown in FIG. 2, a pair of shafts are mounted in piggy-back fashion in bore 76. Provided in housing 74 are a pair of bores 82 and 82' which intersect bore 76. Mounted within bore 82 and 82' are clamping members 84 and 84' having a first male portion 86 and 86' and a second female portion 88 and 88' between which is mounted spring elements 90 and 90'. The spring elements 90 and 90' bias the male portions 86 and 86' against cam surfaces 92 and 92'. Male portions 86 and 86' bias female portions 88 and 88' by means of the force exerted on springs 90 and 90' by cams 92 and 92' provided on shafts 80 and 80' when the shafts 80 are rotated. As can best be seen in FIG. 2, female portion 88 biases against insulating material 26 and in turn induction coil 30. An electrically conductive body 94 is provided on one of the induction coils 30 for completing the electrical circuit between the coils. The shafts 80 are provided with slots 96 which accept a tool for rotating the shafts 80 so as to allow biasing of the clamping member 84 against the coils 30 thereby making electrical contact between the induction coils 30.
Electrical contact is made between the screens 36 in a similar manner. Screen 36 on movable end walls 14 has secured thereto an electrically conductive element 98 which is biased against screens 36 on side walls 12 by clamping members 84' in the same manner as noted above with regard to clamping member 84. An additional clamping member 100 is provided on the support frame 24 for insuring good electrical contact between induction coil 30 and the electrical input, not shown. Conduits 102 communicate cooling liquid between the cooling channels 32 of the induction coils 30.
In accordance with the present invention, in order to insure that the ingots being cast have substantially flat side walls, the side walls 12 of the mold 10 are segmented. When the location of the end walls 14 with respect to the side walls 12 is as shown in FIG. 1, the configuration of the mold 10 is ideal for producing cast ingots having flat side walls. Adjustments of the end walls 14 from that position shown in FIG. 1 results in a less than ideal mold configuration. Thus, the end walls 14 of the mold 10 can only be adjusted from the ideal location a distance which amounts to about 25-35%, preferably about 25-30% the length of the segmented side walls 12.
While there are gaps between the ends of the end walls 14 and the side walls 12, it is critical to the present invention that good electrical contact be maintained between the side wall and end wall inductor portions and shield portions. The electrical contact is made in the manner previously described. Failure to maintain good contact between the shield portions will result in bag ingot surface structure.
By way of the present invention, ingots of various sizes can be cast in a single mold while at the same time insuring substantially flat side walls on the ingots.
It is to be understood that the invention is not limited to the illustration described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modification of form, size, arrangement of parts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims. | An adjustable mold for use in electromagnetic casting systems wherein the side walls of the mold are adjustable so as to allow for the casting of ingots of various sizes by a single mold. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a color cathode-ray tube having an in-line type electron gun structured so as to emit three electron beams in a horizontal plane toward a phosphor screen.
Generally, recent color cathode-ray tubes employ an in-line type electron gun. The in-line type electron gun is structured to emit a plurality of, usually three, electron beams in a common plane (horizontal plane). The plurality of electron beams are focused on a phosphor screen of the color cathode-ray tube to reproduce a color image.
FIG. 3 depicts an axially cross-sectioned view illustrating a prior color cathode-ray tube having an in-line type electron gun. The color cathode-ray tube is made up of a panel 10, a funnel 20, a neck 30, a phosphor screen 40 formed on the inner surface of the panel 10, a shadow mask 50 that is a color selection electrode, and a deflection yoke 60 mounted outside the funnel 20. The in-line type electron gun 70 (hereinafter referred to as the electron gun) is contained in the neck 30. In the figure, R, G, and B denote a red, green, and blue electron beams, respectively.
The three electron beams R, G, and B emitted from the in-line type electron gun 70 are deflected by the deflection yoke 60 horizontally and vertically. The electron beams then are color-selected by the shadow mask 50 and impinge on and excite the phosphor screen 40 of the intended color corresponding to each beam to reproduce a two-dimensional image.
FIG. 4 depicts a vertical cross-sectioned view illustrating a prior in-line type electron gun. The electron gun is made up of a cathode 01, a first electrode 02 (hereinafter referred to as the G1 electrode), a second electrode 03 (G2 electrode), a third electrode 04 (G3 electrode), a fourth electrode 05 (G4 electrode), a fifth electrode 06 (G5 electrode), a sixth electrode 07 (G6 electrode), an aperture 08 of the G1 electrode, an aperture 09 of the G2 electrode, an aperture 010 of the G3 electrode on the G2 electrode side, an opening 011 of the G3 electrode on the G4 electrode side, an opening 012 of the G4 electrode, an opening 013 of the G5 electrode on the G4 electrode side, an opening 014 of the G5 electrode on the G6 electrode side, and an opening 015 of the G6 electrode.
A diameter of the aperture 08 of the G1 electrode 02 is 0.4 to 0.6 mm. A diameter of the aperture 09 of the G2 electrode 03 also is 0.4 to 0.6 mm. The opening 011 of the G3 electrode 04 on the G4 electrode side is around 4.0 mm in diameter. The opening 012 of the G4 electrode 05 also is around 4.0 mm in diameter. The opening 013 of the G5 electrode 06 on the G4 electrode 05 side also is around 4.0 mm in diameter. An axial length of the G4 electrode 05 is 1.0 mm. An axial length of the G5 electrode 06 is 17.3 mm.
The in-line type electron gun structured as described above operates as follows.
Thermoelectrons emitted by the cathode 01 heated by heaters are attracted toward the G1 electrode 02 by a positive voltage of 400 to 1,000 V applied to the G2 electrode 03 to form the three electron beams arranged in a plane perpendicular to the sheet of drawing.
Each of the three electron beams passes through the aperture 08 of the G1 electrode 02 and passes the aperture 09 of the G2 electrode 03. The beam then is preliminarily focused a little by a sub-main lens formed of the G3 electrode 04 having a low voltage of around 5 to 10 kV applied thereto, the G4 electrode 05 having the same voltage applied thereto as a voltage impressed on the G2 electrode 03, and the G5 electrode 06 having the same voltage applied thereto as the voltage of the G3 electrode 04. The sub-main lens is formed of a lens between the G3 electrode 04 and the G4 electrode 05 and a lens between the G4 electrode 05 and the G5 electrode 06. The beam, in turn, is accelerated by a positive voltage applied to the G5 electrode 06, and enters a main lens formed between the G5 electrode 06 and the G6 electrode 07.
A potential difference between the G5 electrode 06 and the G6 electrode 07 with a high voltage of around 20 to 35 kV applied thereto constituting the main lens forms an electrostatic field between the G5 electrode 06 and the G6 electrode 07. Trajectories of the three electron beams fed into the main lens are bent by the electrostatic field.
As a result, each of the three electron beams is focused on the phosphor screen to form a beam spot.
To prevent defocusing of the beam spot at the periphery of the screen, the Japanese Patent Publication No. 53-18866 discloses a color cathode-ray tube having an in-line type electron gun having a rectangular recess elongated horizontally and superposed on the aperture 09 of the G2 electrode 03, on the G3 electrode 04 side.
FIG. 5 depicts a plan view illustrating the G2 electrode having the rectangular recesses elongated horizontally and superposed on the aperture of the G2 electrode 03 on the G3 electrode side. The horizontally elongated rectangular recesses 9a, 9b, and 9c enclose the three respective apertures 9 1 , 9 2 , and 9 3 aligned in line in the G2 electrode 03, on the G3 electrode side.
An appropriate depth in electrode-thickness direction of the rectangular recesses 9a, 9b, and 9c provides electron beams with an appropriate astigmatism to cancel aberrations due to deflection.
SUMMARY OF THE INVENTION
The prior color cathode-ray tubes having the in-line type electron gun structured so far as described involves a problem of generating moire.
The moire is a spurious pattern in a reproduced picture, resulting from interference beats between a periodic structure of phosphor dots and scanning lines or periodic video signals, and deteriorating a resolution, if the beam spot diameter becomes smaller than a certain value. The one with scanning lines is called a raster moire or horizontal moire, the other with video signals is called a video moire or vertical moire.
The above-described prior color cathode-ray tube having the in-line type electron gun having horizontally elongated rectangular recesses superposed on the aperture 09 of the G2 electrode 03, on the G3 electrode 04 side, adversely produces more pronounced vertical moires than horizontal ones due to vertical elongation of the beam spots caused by the recesses.
The reason is described below. The color cathode-ray tube used for a monitor for a computer or the like has to have high resolutions at both a center and a periphery of the screen. For a combination of a screen of 36 cm effective diagonal size and 1,000 or more horizontal dots, and a shadow mask of a 0.31 mm or less mask pitch, the beam spot diameter at the center has to be smaller than 0.7 mm and a ratio in spot diameters of the center to the periphery of the screen has to be 1.0 to 1.3, as described in the "In-Line Type High-Resolution Color-Display Tube," National Technical Report, Vol. 28, No. 1, February 1982.
In the case of the prior in-line type electron gun without horizontally elongated rectangular recesses superposed on the aperture of the G2 electrode, on the G3 electrode side as disclosed in the Japanese Patent Publication No. 53-18866, the spot diameter at the periphery of the screen is strongly affected by aberration due to deflection, and increases to a great extent. It is not possible to make the ratio in spot diameter of the center to the periphery of the screen within the above-mentioned range of 1.0 to 1.3.
For the reason, the prior in-line type electron gun disclosed in the Japanese Patent Publication No. 53-18866 is structure to have the horizontally elongated rectangular recesses superposed on the aperture of the G2 electrode, on the G3 electrode side. Appropriate depth of the recesses is made to provide electron beams with appropriate astigmatism to cancel aberration due to deflection, to make the ratio in spot diameter of the periphery to the center of the screen within the range of 1.0 to 1.3.
However, the spot diameter at the center of the screen is elongated in the vertical direction by astigmatism. If the spot diameter at the center is made to be smaller than 0.7 mm, the spot diameter in the horizontal direction becomes exceedingly small. This makes the horizontal spot diameters small not only at the center, but also over the entire screen, and imposes a problem that vertical moire appears over the entire screen.
In view of solving the foregoing problems of the prior arts, it is an object of the present invention to provide a color cathode-ray tube having an in-line type electron gun that has deterioration in focus characteristics reduced and can obtain a quality image with no moires over the entire screen.
Briefly, the foregoing object is accomplished in accordance with aspects of the present invention by a color cathode-ray tube having an in-line type electron gun comprising electron beam generating means comprising a cathode, a first electrode, and a second electrode for emitting three electron beams toward a phosphor screen, a sub-main lens formed of a third electrode, a fourth electrode and a fifth electrode, and a main lens formed of said fifth electrode and a sixth electrode for focusing said three electron beams onto said phosphor screen in cooperation with said sub-main lens, said second and fourth electrodes being electrically connected together and said third and fifth electrodes being electrically connected together, wherein the ratio A of an axial length of said fourth G4 electrode to a diameter of an opening of said fourth electrode and the ratio B of an axial length of said fifth G5 electrode to the diameter of said opening of said fourth electrode satisfy the following equations:
54A-5B+4≦0,
55A-5B+7≧0,
A-0.18≦0,
and
95A+10B-73≦0,
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 depicts a vertical cross-sectional view illustrating an embodiment of an in-line type electron gun for use in the color cathode-ray tube according to the present invention;
FIG. 2 illustrates a relationship between the ratio A of an axial length of a G4 electrode to a diameter of an opening of the G4 electrode and the ratio B of an axial length of a G5 electrode to a diameter of the opening of the G4 electrode;
FIG. 3 depicts an axially cross-sectioned view illustrating a prior color cathode-ray tube having an in-line type electron gun;
FIG. 4 depicts a vertical cross-sectioned view illustrating a prior in-line type electron gun; and
FIG. 5 depicts a plan view illustrating the G2 electrode having the horizontally elongated rectangular recesses superposed on the aperture of the G2 electrode, on the G3 electrode side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A color display tube having a screen of 36 cm effective diagonal and a shadow mask of 0.31 to 0.26 mm mask pitch will not generate moire if a beam spot diameter is greater than 0.6 mm. To prevent a vertical moire, therefore, a horizontal diameter of the spot at a center of the screen has to be greater than 0.6 mm. To retain a high resolution, an average diameter of the spot at the center of the screen has to be smaller than 0.7 mm. Taking these into account, a vertical diameter of the spot at the center of the screen has to be smaller than 0.8 mm.
The vertical diameter of the spot at the center of the screen changes with a diameter of the beam entering into a main lens. To make small the diameter of the beam spot at the center of the screen, the diameter of the beam entering into the main lens has to be made large to a certain degree.
FIG. 2 illustrates a relationship between the ratio A of an axial length of a G4 electrode to a diameter of an opening of the G4 electrode and the ratio B of an axial length of a G5 electrode to the diameter of the opening of the G4 electrode.
The diameter of the beam entering into the main lens increases as the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode increases, and it decreases as the ratio B of the axial length of the G5 electrode to the diameter of the opening of the G5 electrode decreases.
The relationship between the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode and the ratio B of the axial length of the G5 electrode to the diameter of the opening of the G4 electrode was determined by experiments on electron guns to obtain the vertical diameter of the spot smaller than 0.8 mm at the center of the screen. The relationship between A and B is indicated by the inequality below and by the straight line 16 in the figure.
54A-5B+4≦0
A ratio in a diameter of beam spots of a periphery of the screen to the center of the screen has to be 1.0 to 1.3.
The ratio in the diameter of the beam spot of the periphery of the screen to the center of the screen changes with a diameter of the beam in the deflection magnetic field. The ratio can be made small with the diameter of the beam entering the main lens made small, contrary to the diameter of the spot at the center of the screen.
The relationship between the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode and the ratio B of the axial length of the G5 electrode to the diameter of the opening of the G4 electrode was determined by experiments on electron guns to make the ratio in the diameter of the spot of the periphery of the screen to the center of the screen less than 1.3. The following relationship was obtained as indicated by the straight line 17 in the figure.
55A-5B+7≧0
The ratio of the axial length of the electrode to the diameter of the opening of the G4 electrode is further limited by a focus voltage as another factor.
The focus voltage applied on the G3 and G5 electrodes is supplied via a metal lead embedded in a stem at a bottom of a neck of the color cathode-ray tube. Voltages applied to a cathode, a heater, and a G1 and G2 electrodes are also supplied via other metal leads embedded in the stem at the bottom of the neck of the color cathode-ray tube. If the focus voltage is too high, it causes a problem of electric breakdown that discharges between metal leads.
A voltage around 20 to 35 kV is applied to the G6 electrode. The focus voltage degrades electric breakdown strength when it is higher than 30% of a voltage applied to a G6 electrode. Generally a ratio of the focus voltage applied on the G3 and G5 electrodes to the voltage applied to the G6 electrode increases with the increasing ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode, and also increases with the increasing ratio B of the axial length of the G5 electrode to the diameter of the opening of the G4 electrode.
The relationship between the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode and the ratio B of the axial length of the G5 electrode to the diameter of the opening of the G4 electrode was determined by experiments on electron guns to make the ratio of the focus voltage to be applied on the G3 and G5 electrodes to the voltage applied on the G6 electrode less than 30%. As a result, the following relationship was obtained as indicated by the straight line 18 in the figure.
95A+10B-73≦0
With the length of the G4 electrode decreasing, the structure of the electrode becomes weaker. With the lens diameter of the G4 electrode increasing, a remaining portion (bridge) between the openings for the lens becomes thinner. This also makes fragile the electrode structure.
The inventors found a problem that if the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode was less than 0.18, the electrode structure was so fragile that the electrode was frequently deformed during assembling the electron gun and it was difficult to manufacture the parts.
For the reason, the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode has to be higher than 0.18. The relationship is indicated by the straight line 19 in the figure.
The area in which the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode and the ratio B of the axial length of the G5 electrode to the diameter of the opening of the G4 electrode satisfy the four conditions mentioned above, is hatched in the figure.
If the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode and the ratio B of the axial length of the G5 electrode to the diameter of the opening of the G4 electrode are chosen within the hatched area in the figure, electric breakdown strength can be secured, the parts production can be facilitated, and the vertical moire can be suppressed without deterioration of the focus characteristics.
It is preferable that a voltage applied on the second and the fourth electrodes is lower than 1,000 V, and a voltage applied on the third and fifth electrodes is in the range of 20 to 33% of a voltage applied on the sixth electrode. If the voltage applied on the second and fourth electrodes exceeds 1,000 V, electric breakdown strength deteriorates between the first and the second electrodes and between leads embedded in a stem of a neck. If the voltage applied on the third and fifth electrodes is lower than 20% of the voltage applied on the sixth electrode or higher than 33% of the voltage applied on the sixth electrode, the electric breakdown strength deteriorates between the fifth and the sixth electrodes, or between the second and third electrodes and between leads embedded in the stem, respectively.
It is preferable that the diameter of the sub-main lens (the diameter of the opening of the fourth electrode) is in the range of 3.0 to 6.2 mm. If the diameter of the sub-main lens is smaller than 3 mm, the mandrel jig for assembling an electron gun becomes weak in structural strength, resulting in degradation of accuracy of an electron gun assembly, and if the diameter of the sub-main lens exceeds 6.2 mm, fabrication of the electrode becomes difficult because the outside diameter of the fourth electrode is limited by the diameter of a neck of a glass bulb and the width of a remaining portion between the adjacent openings of the electrodes becomes too small.
The invention will now be described in more detail by way of an embodiment with reference to the accompanying drawings.
FIG. 1 depicts a vertical cross-sectional view illustrating an example of an in-line type electron gun for use in the color cathode-ray tube according to the present invention. The electron gun comprises a cathode 1, a G1 electrode 2, a G2 electrode 3, a G3 electrode 4, a G4 electrode 5, a G5 electrode 6, a G6 electrode 7. The numeral 8 denotes an aperture of the G1 electrode 2, 9 an aperture of the G2 electrode 3, an aperture of the G3 electrode 4 on the G2 electrode 3 side, 11 an opening of the G3 electrode 4 on the G4 electrode 5 side, 12 an aperture of the G4 electrode 5, 13 an opening of the G5 electrode 6 on the G4 electrode 5 side, 14 an opening of the G5 electrode 6 on the G6 electrode 7 side, and 15 an opening of the G6 electrode 7.
A diameter of the aperture 8 of the G1 electrode 2 is 0.45 mm. A diameter of the aperture 9 of the G2 electrode 3 is 0.52 mm. The aperture of the G2 electrode 3 on the G3 electrode 4 side has a horizontally elongated rectangular recess superposed thereon as illustrated in FIG. 5.
Diameters of the opening 11 of the G3 electrode 4 on the G4 electrode 5 side, the opening 12 of the G4 electrode 5 which corresponds to the lens diameter of the sub-main lens, and the opening 13 of the G5 electrode 6 on the G4 electrode 5 side are 3.9 mm. An axial length of the G4 electrode 5 is 1.0 mm. An axial length of the G5 electrode 6 is 16.0 mm.
With the dimensions mentioned above, the ratio A of the axial length of the G4 electrode 5 to the diameter of the opening of the G4 electrode (the lens diameter of the sub-main lens) is 0.26. The ratio B of the axial length of the G5 electrode 6 to the diameter of the opening of the G4 electrode (the lens diameter of the sub-main lens) is 4.10. The ratio A and the ratio B lie within the hatched area indicated in FIG. 2.
In this embodiment, the vertical diameter of the beam spot at the center of the screen was 0.75 mm. The average diameter of the beam spot at the center of the screen was 0.68 mm. A ratio in the spot diameter of the periphery to the center of the screen was 1.20.
It is more preferable that the ratios A and B are 0.26±10% and 4.1±10%, respectively, as well as lie within the hatched area indicated in FIG. 2.
The color cathode-ray tube having the electron gun of this embodiment does not suffer deterioration in electric breakdown strength, difficulties in parts production, or occurrence of objectionable vertical moire in the displayed image.
As described above, the present invention has the relationship between the ratio A of the axial length of the G4 electrode to the diameter of the opening of the G4 electrode (the lens diameter of the sub-main lens) and the ratio B of the axial length of the G5 electrode to the diameter of the opening of the G4 electrode (the lens diameter of the sub-main lens) defined. The present invention provides the color cathode-ray tube having the in-line type electron gun that increases electric breakdown strength, facilitates parts production, and displays quality image with vertical moire suppressed over the entire screen without deteriorating focus characteristic. | A color cathode-ray tube has an in-line type electron gun. Third, fourth, and fifth electrodes form a sub-main lens, and a sixth electrode forms a main lens with the fifth electrode for focusing the three electron beams onto the phosphor screen. The second and fourth electrodes are electrically connected together and the third and fifth electrodes are electrically connected together. A ratio A of an axial length of the fourth G4 electrode to a diameter of the opening of the fourth electrode and a ratio B of an axial length of the fifth G5 electrode to the diameter of the opening of fourth electrode satisfy the following equations: 54A-5B+4≦0, 55A-5B+7≧0, A-0.18≧0, and 95A+10B-73≧0. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates to the deactivation of unexploded munitions.
BACKGROUND OF THE INVENTION
[0002] It is known to render an unexploded munition harmless by cutting through the casing of the munition. Cutting of a large hole itself relieves the pressure and allows the contained explosive to be incinerated without the munition exploding. It is also possible to cut-out and remove the fuse. Because of the danger of the munition exploding while it is being cut, it is important to use a cutting mechanism that can be remotely controlled, to avoid risk of injury to the personnel disposing of the munition. It is also important that the equipment should not have any form of magnetic signature as this could itself set off the munition.
[0003] Known equipment for performing this task (somewhat similar to that described in U.S. Pat. No. 4,703,591 though this patent is only concerned with cutting through glass) consists of a frame that can be placed over the unexploded munition and that movably supports a cutting mechanism. The cutting mechanism is a nozzle connected to a high pressure supply of water containing a suspension of abrasive particles such as garnet or olivine.
[0004] In the known equipment, the tip of the nozzle always remains in a flat plane. The nozzle is supported on a carrier and can rotate about an axis relative to the carrier to cut a circle in the munition. Furthermore the carrier can be moved in a straight line to allow the cutter to cut another circle or to enable the nozzle to cut in a straight line.
[0005] The known mechanism has an important disadvantage in that when cutting along a circle, or along any line transverse to the axis of the cylindrical munition, the distance of the nozzle from the surface of the munition is constantly changing and the movement of the nozzle must therefore be skilfully controlled to reduce the speed of movement of the nozzle as its distance from the cylindrical surface of the munition increases.
[0006] Aside from the skill required in controlling the movement of the cutting nozzle, the known mechanism only allows controlled cutting in one dimension. Once a desired line or circle has been cut, the operator must return to the frame and reposition it so that further lines may be cut. This can potentially result in several trips back to the danger area before the munition can be declared safe.
[0007] DE 4221666 describes an arrangement intended for cutting through munitions. In this case, the munition is itself rotated beneath the cutting head so that a cut is made around the entire periphery of the munition. Such apparatus is totally unsuited to the deactivation of unexploded munition which are too sensitive to be handled in this way.
OBJECT OF THE INVENTION
[0008] The present invention seeks therefore to provide an apparatus that can cut a large hole in the wall of a cylindrical unexploded munition in a simple and effective manner without requiring skilled manipulation of the movement of the cutting head of the apparatus and without requiring the munition to be moved.
SUMMARY OF THE INVENTION
[0009] According to the present invention, there is provided an apparatus for cutting into a cylindrical munition, comprising a cutting head and means for moving the cutting head relative to the surface of the munition, wherein the means for moving the cutting head constrain the cutting head to follow a linear path in one direction, to be positioned in use parallel to the axis of the munition, and in an arcuate path in the plane normal to the first direction to follow the contour of the munition.
[0010] Preferably, the moving means comprises a fixed frame to be positioned adjacent the munition, a carriage movable relative to the fixed frame in the first direction, and a cutting head carrier supported for movement on the carriage and guided to follow an arcuate path centred in use on the axis of the munition.
[0011] Munitions to be deactivated are generally cylindrical devices therefore the movement provided in the present invention allows the cutter to easily perform any cuts on the surface of the munition that the task may require. By providing a linear movement parallel to the axis of the bomb, straight lines along its length may be cut. The provision of an arcuate path allows the cutting head to follow the circumference of the cylinder by arranging the frame in such a position that the axis of the munition and the axis of the arcuate path coincide.
[0012] In the present invention, the head can remain at a substantially constant distance from the surface of the munition throughout the cutting operation, thereby removing the skill required to control the movement of the cutting head. A constant speed can be maintained that is dependent only on the cutting efficiency of the head and the thickness of the wall of the munition. Furthermore, without returning to the site of the munition, it is possible to define any closed path for the movement of the head, enabling a hole of any shape or size to be cut in the wall of the munition.
[0013] As the diameter of munition can vary, it is desirable for the cutting head to be adjustably mounted on the carrier to accommodate munitions of different diameters.
[0014] It is also advantageous to use air powered motors to move the carriage and the carrier through respective reduction gearboxes and lead screws. This avoids the need for an electric current and enables the motor and transmission mechanism to be formed of a material such as aluminium that does not have any magnetic signature.
[0015] To permit remote closed loop feedback control of the movement of the cutting head, shaft encoders may be provided to transmit to a remote monitoring station the current position of the cutting head. Once again, to avoid electric current and any magnetic field, the shaft encoders should desirably the connected by optical fibres to the remote monitoring station.
[0016] As is already known per se, it is preferred to use as the cutting head a nozzle operative to direct a high pressure jet of fluid containing a suspension of abrasive particles onto the surface of the munition. Aside from being efficient at cutting through the casing of the munition, the high pressure water cools the casing during the cutting to minimise the risk of the munition being set off accidentally.
[0017] In the prior art mechanism mentioned above, the abrasive particles are stored in a large tank having an inlet for high pressure water and a separate outlet the water containing the suspension of abrasive particles. A large tank is used, which cannot be carried easily and when it is empty it is refilled on site. There is a risk when refilling the tank that dirt particles of large diameter may enter alongside the abrasive material and such dirt can damage or block the nozzle.
[0018] In the preferred embodiment of the present invention, the abrasive particles are stored in a replaceable canister connected at a T-junction to a high pressure water line leading to the nozzle. The canister is small enough to be carried by one person, and is replenished under clean and controlled conditions. Furthermore, to facilitate the replacement of the canister, a single connection to the canister incorporates an inlet for high pressure water and an outlet for the mixture of high pressure water and particulate abrasive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:
[0020] [0020]FIG. 1 is schematic diagram of the high pressure hydraulic system employed in the preferred embodiment of the present invention,
[0021] [0021]FIG. 2 is a section through the fixing used to attach the canister to the high pressure water system,
[0022] [0022]FIG. 3 is a plan view of the frame to be located about a munition, the drawing showing the carriage, carrier and cutting head;
[0023] [0023]FIG. 4 is a side view of the frame of FIG. 3 as viewed in the direction of the arrows IV-IV in FIG. 3, showing the arcuate path of movement of the carrier relative to the carriage, and
[0024] [0024]FIG. 5 is a similar side view to that of FIG. 4 showing an alternative embodiment of the invention in which the frame is intended to stand to one side of the munition instead of straddling it.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The cutting apparatus illustrated in FIG. 1 comprises three separate assemblies connected to one another by various hydraulic lines. The first assembly 10 consists of a diesel engine 10 (such as a Ruggerini MD 191) driving a high pressure pump 12 (such as a Speck NP25/12-500) that generates an output pressure of around 7000 psi. The pump 12 draws water from a supply tank 14 . The output pressure is limited by a pressure relief valve 16 which dumps excess water back into the supply tank 12 .
[0026] The water under pressure flows through a line 18 containing a non-return valve 20 to the second assembly. The second assembly comprises a canister 24 containing an abrasive such as garnet powder or olivine, which is connected to the line 18 by a T-junction 22 . At this junction, a suspension of abrasive is added from the canister 24 into the water which is then fed by way of a further high pressure line 26 to a cutting nozzle that forms part of the third assembly, to be described below with reference to FIGS. 3 and 4.
[0027] To force the garnet powder out of the canister 24 , a line 30 containing a needle valve 32 , a flow meter 34 , a non-return valve 36 and valve shut off valve 38 leads from a point upstream of the non-return valve 20 to an inlet in the valve at the neck of the canister 24 which is shown in greater detail in FIG. 2. In particular, the high pressure water in the line 30 is supplied at a regulated and measured rate into a port 40 which is connected to a tube 42 immersed in the powder in the canister 24 . The water pressure in the canister is greater than the water pressure at the T-junction 22 (on account of the pressure drop created by the non-return valve 20 ) and this forces water carrying garnet powder through holes 44 into a chamber 46 that is connected to the T-junction 22 through a shorter tube 48 . By varying the quantity of water flowing through the line 30 , it is possible to regulate the concentration of abrasive in the water supplied to the cutting nozzle.
[0028] The valve 38 shuts off the line 30 while allowing clean water to flow through the line 26 and the cutting nozzle, to prevent them from being clogged with abrasive powder.
[0029] The system as described so far differs from prior art equipment in that a single connector at the neck of the canister 24 allows water to be introduced into the canister and water carrying abrasive powder to be extracted from the canister. Hence once the canister is empty of powder, it can be replaced by undoing a single connector. Because of the ease of replacement, the canister can be made relatively small, enabling it to be carried and replaced by a single person. This also adds to the portability of the equipment, which is of prime importance having regard to the terrain over which such equipment often needs to be carried.
[0030] A further advantage is achieved by using replaceable pre-filled canisters in that the canisters can be filled under controlled conditions thereby ensuring that no dirt can be introduced into the system, to risk blocking the cutting nozzle.
[0031] The third station shown in FIGS. 3 and 4 is a nozzle manipulator which can move the cutting nozzle over the surface of the munition in a controlled manner. This station needs to be physically separated from the other two because it cannot have a magnetic signature nor should it carry an electric current that might set off the munition.
[0032] The manipulator, as shown in FIGS. 3 and 4, comprises a frame 50 that stands above the munition 52 on four legs 54 that are all telescopically adjustable. Suspended from the frame 50 is a fixed gantry 56 along which there is movably mounted a carriage 58 . The carriage 58 can be moved along the gantry 56 by means of an air motor 60 fitted with a reductions gearbox and driving a lead screw which threadedly engages with a nut connected to the carriage 58 . In use, the frame 50 is positioned and the lengths of the legs 54 are individually adjusted such that the gantry 56 lies generally parallel to the axis of the munition 52 .
[0033] A carrier 62 supporting the cutting nozzle 64 is mounted on the carriage 58 in such a manner as to enable the nozzle 64 to move in a circle centred on the axis of the munition. To this end, the carriage 58 supports two fixed rollers 66 and the carrier 64 has an arcuate surface that rests on the rollers 66 . Through a pivoted connecting rod 68 , represented schematically in FIG. 4, the carrier is connected to a second air motor and reduction gearbox that is mounted on the carriage 58 .
[0034] To cope with munitions having different diameters, the radial position of the nozzle 64 on the carrier is adjustable as represented by the vertical double headed arrow in FIG. 4.
[0035] Shaft encoders are provided (only the encoder 80 associated with the motor 60 being represented in the drawing) to determine the position of the carriage 58 along the gantry 56 and the extension of the connecting rod 68 to allow the actual position of the cutting nozzle 64 to be relayed by optical fibres 82 to the second of the stations, where the cutting path can be programmed by an operator into a computer which may then remotely control the movement of the nozzle 64 using closed loop control to follow the desired path.
[0036] In the prior art equipment, the requirement for manual control necessitated the use of visual monitoring equipment, i.e. a closed circuit television system, and though such equipment may be provided to reassure the operator of correct operation of the equipment, it is not essential to the performance of the apparatus.
[0037] The apparatus of the embodiment of FIGS. 3 and 4 is essentially the same as than of FIG. 5 and to avoid repetition of the description, the same reference numerals have been allocated to components that serve the same function as previously described. The important difference to note is that the frame 50 is designed to stand to one side of the munition instead of straddling it. Suitable adjustable feet (not shown) are provided on the frame to allow it to be positioned, as previously, so that the carriage 58 moves parallel to the axis of the cylindrical munition 52 and the arc of the cutting head is centred on the axis of the munition.
[0038] This embodiment has the advantage that the manipulator can be positioned next to the munition and does not have to be carried over it. Furthermore, the cutting head now cuts a hole in the side rather than the top of the munition and this has the advantage that the removed metal tends simply to fall out of the hole that has been created, By contrast, when cutting a hole from above, the removed metal drops into the hole and its withdrawal from the hole creates an unnecessary problem. | An apparatus for cutting into a cylindrical munition, comprising a cutting head ( 64 ) and means for moving the cutting head relative to the surface of the munition. The means for moving the cutting head constrain the cutting head to follow a linear path in one direction, to be positioned in use parallel to the axis of the munition, and in an arcuate path in the plane normal to the first direction to follow the contour of the munition. | 1 |
[0001] The present invention relates to the field of data processing systems, and more particularly to the logging of data within such systems.
[0002] Many software systems that manage important data record all updates to non-volatile data in what's known as a log. FIG. 1 provides an overview of the process according to the prior art. A central server 10 holds some non-volatile data 20 . A client 50 runs software 60 that causes some of the data 20 to be updated, for example, via a network connection to the server (not shown). The updated information is first stored in a buffer at the server (not shown) and at a predetermined point in time, the updated data is written out to a log 40 . This, along with the buffering, is controlled by a log management component 45 . The purpose of the log is to provide a high-integrity history of the data 20 and the operations upon it for recovery purposes. Note, the software for updating data 20 may run as a separate process at the server. Further the log 40 may sit across the network.
[0003] The logical view of the data in the log is of a sequence of records. New data is written to the end of the sequence and records are never changed once written. FIG. 2 a shows an exemplary logical view of a log according to the prior art. In this example, there are three records A, B, C and these occupy one contiguous area of storage which grows from left to right (see time arrow).
[0004] The physical view is quite different. The data in the log is split into fixed-size blocks called pages, each of which is typically 4 Kilobytes in size. Records are tightly packed into the pages without any gaps between them. Page boundaries are overlapped where necessary. FIG. 2 b shows an exemplary physical view according to the prior art. A page may consist of whole record(s) (A), a number of record fragments (B 1 , B 2 , C 1 , C 2 , C 3 ), or a combination of the two. Record fragments correspond to those records that have been split across page boundaries. For example, it can be seen that C 1 , C 2 and C 3 constitute a record C. Note, each log record in the log is uniquely identified by a number called its Log Sequence Number (LSN). An LSN gives the byte offset of the start of a record from the beginning of the log, and so it is a simple matter to calculate the location of a log record given its LSN.
[0005] Typically, the last page in the log is only partly filled and is known as a partial page 100 . When a new record is added to the log, it may fill a partial page with data and cause a new partial page to be added to the end of the log.
[0006] While it is true in the logical view of the log that data is only ever appended to the end of the log, in the physical view, this is not necessarily true and existing pages of log data can be overwritten. It is not possible to guarantee that all of the data in a page will be written atomically as a single operation and indivisible in any way. During the overwriting process, it is possible for the page to become corrupted. By way of example, a partial page contains a record fragment C 3 as shown in FIG. 2 b . A further write would cause that partial page to be overwritten with the C 3 fragment and another record (D) or record fragment (D 1 ) such that in the majority of cases, the page is filled. However, if the power is lost, for example, while the page is being overwritten then the page may be written incorrectly such that the C 3 fragment is incomplete or not there at all.
[0007] It is therefore necessary to ensure that log records are not lost or corrupted unintentionally. One such method is to rely on fault-tolerant hardware, such as, for example, a SSA fast-write cache. This is a cache typically within a disk drive housing the log. When a server's operating system (o/s) issues a write to the disk drive this gets stored in the cache and control is relinquished back to the o/s for further transaction processing. The data can then be written out to disk asynchronously. Caching to volatile memory is disliked since it jeopardizes data integrity. This is because the o/s is fooled into believing that a transaction or transaction part has been recorded on disk when in reality this is yet to happen. If volatile memory fails then the data within is lost. A SSA fast-write cache however is battery backed (i.e. a power failure would not be a problem, since the batteries would simply take over). This kind of system is however extremely expensive and not cost effective in most commercial environments.
[0008] 1Another method is illustrated by FIG. 3. It can be seen that each write starts a new page. Hence there is no chance of corrupting the most recent version of a page. Record A makes for a partial page X at position N. When the next data segment B arrives, the segment A from page N concatenated with B 1 is written to N+1 and the remaining portion of B, which is B 2 , is written to page P in this example. The partial data segment B 2 at page P again makes for a partial page when data segment C arrives and this is written to page P+1. A fuller version of that page Y(ii) is written to position P+1 and the complete version Y(iii) is written at position P+2 when data segment D arrives. What should be a single page of log data might therefore actually occupy more than one page of space in the log. This makes reading the log inefficient and it also makes it harder to manage the space requirements of the log. Housekeeping functions activated by the log management component typically determine that a particular page is redundant and available for overwriting (e.g. old versions of page Y(iii)). Note, the complete versions of pages may also be available for overwriting (i.e. if a checkpoint has been taken which includes those pages). However this method does mean that the log fills up more quickly and partial pages will be mixed in with full pages, both of which are undesirable. Further, it is not possible to predict the position of a particular log record via its LSN. Instead it would be necessary to scan the log each time a record was read or to hold some kind of directory information about the log records to locate a particular record. This is undesirable.
[0009] A careful-writing scheme or algorithm is therefore typically adopted to ensure that data that has already been written to the log is not corrupted by subsequent writes. The ping-pong algorithm is one example of such a scheme and is used, for example, by DB 2 Universal Database, available from IBM Corporation. In this scheme, if there is a partial page of data at log page N when new data arrives, the contents of N concatenated with all or a portion of the new data is first written into N+1 to avoid the possibility of corrupting the data in N. Then the contents of N+1 are written into N. Finally, if there is a portion of the new data remaining not yet logged, that portion is written into N+1 to form a new partial page. As long as incoming data segments do not completely fill a page, the segments are added to N and N+1 in an alternating manner, ensuring that the previous, most recent version of data is not corrupted when the newer version is written. When the page is being read, it is necessary to check both in location N and location N+1 to determine the most recent version of data or to keep track of that in some other manner, such as by using a toggle flag. Either version of the page may be newer depending on how many times the page has been updated. When the page is finally filled, it is written to its own proper location N before the first version of the next page of the log can be written into the next location N+1. This scheme gives the advantage that you can calculate the location of a log record by its LSN.
[0010] Although data corruption is, in the main, prevented, a major disadvantage of the ping-pong scheme is efficiency. In this scheme, along with the other methods mentioned above, data is written directly to the log without caching by the central server's operating system or hardware (not shown in FIG. 1). So, when the log management component issues a request to the operating system to write data to the log, control is not returned to the log management component until the data is correctly recorded in a non-volatile medium. This is necessary since the server needs to know that data has been correctly written to the disk to ensure data integrity (see above). This also means that it is time-consuming to write data to the log because the cost of waiting for the relatively slow disk drive cannot be amortized across many write operations by use of a cache. Luckily, when most records are written to the log, they do not have to be recorded until a point of consistency such as the completion of a unit of work. However, the cost of writing to the log is still a major factor in the performance of many data systems. In striving to avoid the consequences of data corruption, the ping-pong scheme requires that when a page is first written as a partial page, the page is typically written three times before a page is completely full and data is in the proper sequence in the log
[0011] [0011]FIG. 4 illustrates the operation of the ping-pong scheme and the performance problems associated with it. (Note, the pages with the thick borders indicate the data actually written by each disk write—this is also so in FIGS. 5, 10 and 11 .) As previously mentioned, it is common for the last page in a log to be written as a partial page and for it to be filled via subsequent writes. Typically, the page is full by the time the second write has been completed. Thus in the FIG. 4, partial page 200 represents the “before” scenario in which a partial write of A has already been performed into N. A new record with fragment B 1 makes for a full page 200 ( i ), which is written (Write 1) to position N+1 such that there is no risk of overwriting the most recent version of the page 200 at position N. Write 2 subsequently copies the full version of the page 200 (ii) from N+1 back to its expected location at position N. A third write writes the next partial page 210 (the remaining fragment B 2 of B) into position N+1. The next page at position N+2 (not shown) then becomes available for the ping-pong pair for partial page 210 .
[0012] Logically, it is unnecessary to write page 200 ( i ) into position N+1, but this is required to ensure that the latest version of page 200 in position N is not corrupted by a write into that page with the only copy of update A. Similarly, it is not permitted to combine writes 2 and 3 into a single write since it is possible to corrupt the data in both locations N and N+1. (This would, however, make for a less I/O bound solution.) Such an invalid write operation is shown in FIG. 5. It can be seen that write 1 writes the full version of the page 200 ( i ) to position N+1 (as in FIG. 4) and write 2 then writes this into position N and page 210 into position N+1. However, it is possible on this single Write 2 to corrupt both N and N+1.
[0013] Data is written out to disk a sector at a time. A disk sector is typically 512 bytes, whereas a page is typically 4 Kilobytes. Thus it is quite possible that data will not be written out from the beginning of a page. Further, disk drives commonly optimize the order of writing to match the position of the disk under the write head at the time that the request arrives in the disk drive. Since the sectors which have to be written to the disk drive are not therefore necessarily written in the order which one might expect, it is possible that only part of page 210 is written, followed by part of page 200 (ii), followed by a power failure. If this happens then both page 200 and page 200 ( i ) are corrupted and records lost. FIG. 6 illustrates this problem. In aiming to write the full version of page 200 (ii) and partial page 210 in one write (write 2), the problem outlined above occurs. The write head begins writing at location R and continues up to location S. Note, location R is not at the beginning of partial page 210 . Writing then starts again at location T and ends abruptly at location U due to, for example, a power failure. The logical view of the end of the log is as if page 200 (ii) does not exist because both copies ( 200 ( i ) and 200 (ii)) of that page are either overwritten or corrupt. The data in location N contains a corrupted version 202 of page 200 (ii). Location N+1 contains a corrupt page 205 consisting of some of page 200 (ii) and some of page 210 . There is no longer a good copy of page 200 (ii) and so no way of recovering the information.
SUMMARY OF THE INVENTION
[0014] Accordingly, the invention provides a method for logging updates to a plurality of data records, wherein the updates are logged to an area of non-volatile storage and the storage area is divided into a plurality of discrete pages, wherein a page partially full of data is known as a partial page.
[0015] Identical partial pages I and I+1 are established at the earliest opportunity as part of the logging process. In response to a data segment D larger than the remaining space of a most recent updated partial page I, D is partitioned into a first segment D 1 sufficient to fill the remaining space of page I and a second data segment D 2 . Page I is filled with a first write operation that contains its present contents concatenated with D 1 . In addition, identical partial pages I+1 and I+2 are created by writing D 2 to them in a single, second write operation. The identical partial pages I+1 and I+2 become the identical partial pages I and I+1 for the next logging operation. Thus, the invention operates to update a log in the situation described in two write operations instead of three, as in the known ping-pong method.
[0016] It is possible to receive a succession of one or more data segments that do not fill a page or a partial page. In the preferred embodiment, in response to successive data segments D, the first of which is smaller than the remaining space of the most recently updated partial page I, page I+1 is written to the present contents of page I concatenated with D. Thereafter, this procedure is alternated between pages I and I+1 until a data segment X fills the remaining space of the page containing the most recent update. Then the string consisting of the most recent update concatenated with the new data segment X is partitioned into segments D 1 and D 2 , wherein D 1 is written into page I and D 2 is written into both pages I+1 and I+2 in a single write operation as described above. In an alternative embodiment, in response to successive data segments X, the first of which is smaller than the remaining space of the most recently updated partial page I, page I+1 is written to the present contents of page I concatenated with X. Thereafter, this procedure is continued into successive pages I+2, I+3, etc. until a data segment X fills the remaining space of the page containing the most recent update. Then, the most recent update concatenated with the new data segment X is partitioned into segments D 1 and D 2 , wherein D 1 is written into page I in a first write operation and D 2 is written into both pages I+1 and I+2 in a second write operation.
[0017] The invention might advantageously be used in many types of software systems, including relational databases, reliable messaging systems (e.g. MQSeries available from IBM Corporation) and component transactions servers. For example, in a messaging system which provides once-and-once-only delivery semantics for messages sent between applications communicating across a network via the messaging system, the message data and control information for reliable message transmission could be recorded in a log. In such a system, performance tests indicate, according to the preferred embodiment, up to 20% increase in throughput for a simulation of a typical workload attributed to the disclosed optimization. (Note, in MQSeries for typical workloads it is rare for more than two partial versions of a particular page to be written before the page is filled.)
[0018] An additional advantage is that this optimization does not change the format of the log data or any logic not concerned directly with writing log records. It is therefore still possible, according to the preferred embodiment, to calculate the location of a log record given its LSN.
[0019] According to another aspect, the invention provides a computer program product comprising computer program code stored on a computer readable storage medium or a carrier wave containing computer program code which, when executed on a computer, performs the method described above.
BRIEF DESCRIPTION OF THE DRAWING
[0020] A preferred embodiment of the present invention will now be described, by way of example only, and with reference to the following drawings:
[0021] [0021]FIG. 1 shows an overview of logging according to the prior art;
[0022] [0022]FIG. 2 a shows the logical view of the records in a log;
[0023] [0023]FIG. 2 b shows the physical view of the records in a log;
[0024] [0024]FIG. 3 illustrates a known method of ensuring that pages in a log are not unintentionally lost or corrupted;
[0025] [0025]FIG. 4 illustrates another known logging method referred to as the ping-pong scheme;
[0026] [0026]FIG. 5 shows a variation on the ping-pong scheme, where data integrity is compromised by combining two write operations into a single write;
[0027] [0027]FIG. 6 shows one way the data integrity is compromised by the single write variation of the ping-pong scheme of FIG. 5;
[0028] [0028]FIGS. 7 and 8 illustrate with flowcharts the operation of the present invention according to a preferred embodiment;
[0029] [0029]FIG. 9 illustrates a log after a partial page has been written into two consecutive log pages in accordance with the invention; and
[0030] [0030]FIGS. 10 and 11 illustrate two examples of log operations as an aid to the understanding of the flowchart of FIGS. 7 and 8.
DETAILED DESCRIPTION
[0031] According to a preferred embodiment, the present invention provides an optimized ping-pong algorithm. The modified algorithm optimizes the typical case in which a partial page remains after a performing a logging operation. For all other situations the number of writes required to create a proper log is preferably the same as for the un-optimized ping-pong algorithm.
[0032] [0032]FIGS. 7 and 8 are flowcharts of the operation of the present invention according to a preferred embodiment. They should be read in conjunction with FIGS. 9, 10 and 11 which show the format of log records written out for two illustrative conditions. FIGS. 9 and 10 shows the typical case in which the previous log operation created identical partial pages at N and N+1 and the present log operation typically creates the same situation in two writes of the log instead of three writes, as in the prior art. FIG. 11 illustrates the situation in which one or more updates do not fill a partial page. In this situation, locations I and I+1 are used alternately to store the updates until an update results in filling the most recent partial page. After that operation, the typical case of two identical and consecutive partial pages is reestablished, as per FIG. 10.
[0033] The algorithm starts at step 702 where the loop variable I is initialized to zero. Step 704 resets variables FLAG 1 and FLAG 2 . FLAG 2 is used to signal that the most recent update did not fill a partial page and a state is in effect of alternately using pages I and I+1 to log updates until a page is completely filled. When this state is in effect, FLAG 1 keeps track of which page I or I+1 was used for logging the last update. This is described fully below at the appropriate point. Step 706 waits for a data segment D to arrive for logging. When it does, step 708 sets variable S to the size of a log page. Step 710 determines if the size of the incoming data segment D is greater than the page size in S. If the answer is yes, step 712 divides D into two parts, D 1 that fits into the page pointed to by I (I is zero at this point) and the remainder D 2 ; step 712 stores D 1 into page P(I) in a first write operation. Step 712 also uses a single second write operation to store D 2 into the next two page locations I+1 and I+2, thereby creating two identical partial pages at these locations. The single write is made possible by filling a write buffer with D 2 , followed by fill data for the remainder of page I+1, followed by D 2 again for page I+2. At this point, the algorithm has created the “Before” situation shown in FIGS. 10 and 11. Step 714 increments I and goes to entry B in FIG. 8.
[0034] If the first data segment D does not fill a page, step 716 determines if its size is less than a page. If it is, step 728 writes the entire segment D into P(i) and P(I+1) in a single write operation. Again, this creates the “Before” case of FIGS. 10 and 11. Step 714 is executed to increment I and go on to B in FIG. 8.
[0035] If neither steps 710 or 716 are satisfied, then the size of D must equal exactly that of a log page. In this case, step 718 stores D in P(I) and step 720 increments I. Since there is no resulting partial page, the situation is equivalent to the beginning when I was zero. Therefore, control is returned at 722 to entry A at 726 to continue this introductory part of the algorithm until two consecutive partial pages are created.
[0036] The above process continues until a log operation results in the creation of two consecutive identical partial pages. Normally this happens very quickly. When it does, control is passed at step 724 to entry B in FIG. 8. FIG. 9 illustrates the state of the log at this time, where the upper dark hatched pages represent zero, one or a small number of initial log operations that occurred before creating the partial pages containing D 2 at I and I+1.
[0037] With reference now to FIG. 8, step 802 waits for the arrival of the next data segment D. When it arrives, a determination must be made as to the size of the space remaining in the page to be used in logging this data. This page can be I or I+1 depending on the state of affairs. If FLAG 2 is 1, the state of alternately using pages I and I+1 to log operations is in effect and FLAG 1 keeps track of which page I or I+1 has the most recent update. If FLAG 1 is 1, then page I+1 contains the most recent update; otherwise page I contains the most recent update. If both FLAG 1 and FLAG 2 are set to 1, step 804 sets S equal to the size of the remaining space of page I+1 and it sets the variable DATA to the contents of page I+1. In all other cases, step 805 sets S equal to the size of the remaining space of page I and DATA to the contents of page I. Step 806 now determines if the size of D is greater than S. If so, then the present operation will fill the present page with a partial segment D 1 and leave a remainder segment D 2 . Step 807 first determines which page (I or I+1) contains the last update. If FLAG 1 =0 and FLAG 2 =1, then page I contains the last update. To protect the last update, the next write must be to page I+1. Therefore, in this case, step 808 sets page I+1 to the concatenation of the DATA (the last update) and D 1 . If that write is successful, step 809 next sets page I to DATA concatenated with D 1 . The log is now in a proper sequence. Step 809 also in a third write establishes identical partial pages I+1 and I+2 by setting them to D 2 in a single write operation. Returning to step 807 , if the question there is not satisfied, then page I+1 contains the most recent update. In this case, there is no reason to perform step 808 . Rather, step 809 fills the present page I with DATA concatenated with D 1 and it also establishes with a single second write the identical partial pages I+1 and I+2 set to D 2 . The result is shown in FIG. 10, in which BEFORE represents the state of the log before D arrived, C 2 concatenated with D 1 is written into page I in a first operation, and if that write is successful, D 2 is written into both pages I+1 and I+2 in a second write operation.
[0038] At step 806 , if the size of the data segment D is not greater than the value in S, then step 816 determines if it is less than S. If so, a portion of the algorithm is now begun in which the consecutive partial pages I and I+1 are used to log operations safely until an operation occurs that fills the most-recent updated page. An example of this is shown in FIG. 11. Step 818 determines if FLAG 2 is already set. If not, this is the first iteration in which an update does not fill the present page. In this case step 820 sets both FLAG 1 and FLAG 2 TO 1; step 822 uses page I+1 to store the present contents DATA (the contents of page I) concatenated with the data segment D. Write 1 of FIG. 11 shows this operation in which segment D, which does not fill partial page I, is added to page I+1 in a single write operation. The variable I is not incremented because a new page has not been filled by this operation. Control is then passed to entry B to await the next data segment.
[0039] Continuing with this last example, when the next segment D arrives, it may also be of such a size that it still does not fill the remaining contents of page I+1. In this case, step 804 will set S to the remaining size of the page I+1, and step 816 will be satisfied. Since FLAG 2 is already set as well as FLAG 1 , step 824 will reset FLAG 1 to 0 and step 826 will store in page I (page I+1 was last used) the value of DATA concatenated with D. This scenario of alternately using I and I+1 to log updates will continue until an update results in at least filling the page I or I+1 that contains the last update. Write 2 of FIG. 11 gives an example of this operation, in which a portion E 1 of the next segment E to arrive fills the remaining space of the most recent update (page I+1 in this example). Therefore, in this example, the concatenation of the most recent update (C 2 and D) and E 1 is written into I on Write 2. At this time, step 808 will re-establish the state of FIG. 10 in which page I is completely filled and pages I+1 and I+2 contains identical partial pages. Write 3 of FIG. 11 illustrates this, in which the remaining portion E 2 of E is written into I+1 and I+2 in a single write. It is also possible, of course, that page I becomes exactly filled (there is no partial page), in which case the following occurs.
[0040] If when logging a data segment, the update exactly fills the remaining space in page I (or in page I+1 if the FLAG 2 state is in effect and page I+1 was last updated), then both steps 806 and 816 fail. Step 830 determines which page I or I+1 contains the last update. If its page I, then step 831 writes page I+1 to the concatenation of DATA and new data segment D and step 832 then writes page I to the same value. If page I+1 contains the most recent update, step 831 is omitted for the same reason as described earlier with reference to step 807 . Page I is now filled and there is no new partial page. Therefore, the algorithm is essentially re-started as if the next page were the initial page. Step 833 resets both flags FLAG 1 and FLAG 2 . Step 836 increments I and return is made at 838 to entry A in FIG. 7 to continue the process.
[0041] According to the preferred embodiment, when incoming segments D don't completely fill a partial page, then pages I and I+1 are used alternately to store each successive segment with the last saved state until a page is filled. It should be recognized that successive pages, i.e. I+1, then I+2 and so on, can be used for the same purpose instead of I and I+1. In other words, I might contain D 1 , I+1 might contain D 1 +D 2 , I+2 might contain D 1 +D 2 +D 3 , where all of the D's represent successive data segments that individually and concatenated do not fill a page. Eventually when an update does fill a page, the most recent page concatenated with the new segment is written to I and the process is then re-initialized to start again.
[0042] According to the preferred embodiment, the invention trades the cost of writing a duplicate copy of the last page of the log against the cost of a third disk write in the common case where the last page of the log is written once as a partial page and then the next time as a full page. It is common for only one version of a partial page to be written, before the page is overwritten with a full version and so the optimization is an important one. An additional advantage is that this optimization does not change the format of the log data or any logic not concerned directly with writing log records.
[0043] Examples of software systems which could use a log include relational databases, reliable messaging systems (e.g. MQSeries available from IBM Corporation) and component transactions servers. For example, in a messaging system which provides once-and-once-only delivery semantics for messages sent between applications communicating across a network via the messaging system, the message data and control information for reliable message transmission could be recorded in a log. In such a system, performance tests indicate, according to a preferred embodiment, up to 20% increase in throughput for a simulation of a typical workload attributed to the optimization disclosed.
[0044] Throughout the present application writing/adding to the end of the log has been referred to. It is to be understood that the end of the log, may actually constitute the next available location, which could, for example, be at the beginning of the log if the log has been filled and has wrapped round (e.g. in circular logging) or the next suitable position which is not necessarily the next available location. Housekeeping functions preferably determine which pages are available for overwriting. Further, a partial page is not always written. A full page may be written at a first attempt. | A technique of logging updates to a plurality of data records into discrete pages in non-volatile storage, wherein a page partially full of data is known as a partial page. Identical partial pages I and I+1 are established in the logging process as quickly as possible. Thereafter, in response to a data segment D larger than the remaining space of a most recent updated partial page I, D is partitioned into a first segment D 1 sufficient to fill the remaining space of page I and a second data segment D 2. Page I is updated with a first write operation to its present contents concatenated with D 1, and identical partial pages containing D 2 are created at I+1 and I+2 with a second write operation, whereby those pages become pages I and I+1 for the next logging operation. | 8 |
FIELD OF THE INVENTION
[0001] The invention relates to the technical field for fault tree analysis for the instrument control process, especially the fault tree analysis system for a nuclear power plant with advanced boiling water reactor.
DESCRIPTION OF THE PRIOR ART
[0002] With the flourishing development of digitization technology, the stability and the reliability for the network system and the related parts and modules for digitized instrument control have reached to the standard for extensive applications to high-risk facilities. Therefore, large-scale instrument control system that stresses reliability preferably uses network system as the framework for instrument control signal transmission. The nuclear power plant with advanced boiling water reactor that adopts digital instrument control has very different control system operation than the traditional all-analog control system. As a result, when the nuclear power plant with advanced boiling water reactor is executing PRA, the analyst always fails to use a suitable fault tree analysis to assess every risk parameter for digital instrument control.
[0003] The design of digital instrument control for the nuclear power plant with advanced boiling water reactor is to change the hard wire signal transmission for the traditional nuclear power plant to network system signal transmission. Although it greatly reduces hard wire and the quantity for various instrument control units in the signal transmission process, it also brings about issues like network system reliability and common cause failure that would affect the reliability for the entire digital instrument control system. Besides, the detectors for water level, pressure, temperature and rotation speed in a nuclear power plant with advanced boiling water reactor are not completely digitized and still use traditional analog signal transmission. The control unit for actuation equipment is also not completely digitized and still only accepts the traditional analog signal. For risk assessment for the control system with both traditional analog and digital instrument control, the present stage only involves the reliability analysis for a single system. For system design, due to lacking suitable fault tree analysis for digital instrument control in PRA, it fails to conduct all application assessments for the nuclear power plant with advanced boiling water reactor.
SUMMARY OF THE INVENTION
[0004] For safety consideration, the safety equipment for the nuclear power plant with advanced boiling water reactor is operated with multiple signal sources and mixed traditional analog signals and digital signals to increase signal reliability. After reviewing the nuclear power plant with advanced boiling water reactor for safety and non-safety related digital instrument design and including eight instrument control modules, the entire digital instrument control process is divided to six different types, based on which the standard fault tree is developed to support PRA for the needs like simulated signal detection, transmission, logic operation and equipment operation. Therefore, the developed PRA may properly reflect the importance of digital instrument control process on risk.
[0005] The developed fault tree will use external connection mode to simulate the failure mode for each instrument control module and cover all basic events in PRA, including detection unit failure, digital instrument control unit failure, power failure, common cause failure for the same type of modules and personal operation errors.
[0006] To conduct signal failure analysis for the instrument with multiple signal sources, the system fault tree from the invention can be used to establish procedures for signal split, corresponding standard fault tree selection and fault tree connection etc. It is fast and accurate to establish instrument operation fault tree.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 : Flow process diagram for automatic actuated equipment with single measurement unit (mode 1 );
[0008] FIG. 2 : Flow process diagram for multiple measurement unit after logic operation to automatically actuate multiple equipments (mode 2 );
[0009] FIG. 3 : Flow process diagram for mechanical operation panel to actuate single equipment (mode 3 );
[0010] FIG. 4 : Flow process diagram for mechanical operation panel to actuate single equipment (mode 4 );
[0011] FIG. 5 : Flow process diagram for touch screen display to actuate single equipment (mode 5 );
[0012] FIG. 6 : Flow process diagram for touch screen display to actuate multiple equipments (mode 6 );
[0013] FIG. 7 : Standard fault tree for mode 1 ;
[0014] FIG. 8A˜8E : Standard fault tree for mode 2 ;
[0015] FIG. 9 : Standard fault tree for mode 3 ;
[0016] FIG. 10 : Standard fault tree for mode 4 ;
[0017] FIG. 11 : Standard fault tree for mode 5 ;
[0018] FIG. 12 : Standard fault tree for mode 6 ;
[0019] FIG. 13 : Common standard fault tree for unit failure; and
[0020] FIG. 14 : Actual example for instrument control signal transmission for a nuclear power plant with advanced boiling water reactor.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In the design of the digital instrument control for a nuclear power plant with advanced boiling water reactor, the master control room is responsible for signal logic operation and automatic and manual signal generation. Various types of signals subject to signal logic operation come from reactor building, control room building, steam generator building and switch building, where the detection units are located. The signal actuation r equipment in the control room is also located in the above buildings. The signal transmission between buildings, switch buildings and master control room is completed through network system. To comply with the characteristic for network system to transmit digital signals only, the analog signal generated by the detection unit is converted to digital signal before entering network system. The digital signal from the network system is also converted to analog signal first to comply with the characteristic for equipment actuation to accept analog signal only.
[0022] The digital instrument control design for the nuclear power plant with advanced boiling water reactor can be divided into the following eight different units, which can facilitate the simulation for signal transmission and operation by Boolean algebra during fault tree analysis.
[0000] The following Provides Details About the Function and Characteristics for Each Unit:
[0023] Detection Unit (DU):
[0024] They are responsible for detecting signals of water level, pressure, temperature and rotation speed and output continuously analog signals.
[0025] Signal Convert Unit (SCU):
[0026] They are responsible for signal conversion. When the input signals are analog, they will be converted to corresponding digital signals and sent out. When the signals are digital, they will be converted to corresponding analog signals and sent out and sent out. Each signal conversion unit is only responsible for a single signal conversion. Thus, each measurement unit or actuation unit has its own designated signal conversion unit to handle single conversion for a single signal.
[0027] Data Trip Unit (DTU):
[0028] They are responsible for verifying digital signals from measurement units. When the signal meets the default setting, it outputs digital trip signal, which can be transmitted to equipment end to actuation single equipment or to logic processing unit for logic operation.
[0029] Network Unit (NU):
[0030] They are responsible for signal transmission between main control room and other remote control unit. Although network units can transmit massive volume of signals, to prevent single failure to adversely affect instrument control system, the nuclear power plant with advanced boiling water reactor divides the network units to safety and non-safety related types. All the non-safety related signal transmission is through a single non-safety related network unit. Since the safety related signal transmission involves safety related system operation, network units are deployed according to safety system division. Each safety related division has a completely independent network unit. All safety related signals are transmitted through the network unit in their designated division.
[0031] Logic Processing Unit (LPU):
[0032] They are responsible for all signal logic operation and output the results to equipment actuation units to activate the equipment startup, shut off, operation and stop. Besides outputting single signals to actuation single equipment, they also output multiple signals to actuation multiple equipments according to logic setting. Because of the need of receiving signals from different terminals, the unit is always located in the control room and all digital signals through network unit transmission are concentrated in the logic processing units in the control room for further logic operation. The output signals are also transmitted to the destination through the network unit.
[0033] Equipment Actuation Unit (EAU):
[0034] Equipment actuation unit is located near the equipment to be actuated and responsible for equipment startup, shut off, operation or stop according to the input signals. Since the unit only accepts analog signal, when the source signal is digital, it is necessary to convert it to analog signal through signal conversion unit.
[0035] Mechanical Signal Generation Unit (MSGU):
[0036] The manually generated equipment actuation signal can be designed to be digital or analog. When the designed output signal is digital, it can be transmitted to destination through network unit or after logic operation by logic processing unit it become single equipment actuation signal or multiple equipment actuation signal. If the designed output signal is analog, it will be transmitted through the designated signal transmission line directly to the equipment actuation unit. The unit is located on the control panel of the control room and operated by the operation room personnel through press button or turn knob to drive the unit to generate the preset analog or digital output signal.
Video Signal Generation Unit (VSGU):
[0037] This is a unique design for the nuclear power plant with advanced boiling water reactor. Through a single screen, it enables a large number of system or module operations. Through tough screen function the operator can touch and select the control menu for the operation system or module to be operated and through the operation function on the control menu touch and select the desired system or module. The unit is located in the control room and comprised of the screen for display and operation, the computer for display management and operation, and the unit to generate and output digital signals according to the setting. After the operator makes a selection on the touch screen, the unit generates the corresponding digital output signal, which then through logic processing unit drives multiple systems or is directly transmitted through network unit to the corresponding equipment actuation unit to drive single system or equipment.
[0038] After dividing the entire digital instrument control system into the above eight units, the related digital instrument control for the nuclear power plant with advanced boiling water reactor according to the actual design can be divided into six operation modes as shown in the figures from FIG. 1 to FIG. 6 . The blocks in the figures represent instrument control units. Signal transmission is represented by solid line for analog signal and by dot line for digital signal through optical fiber. The standard fault tree corresponding to each operation mode is shown in sequence from FIG. 7 to FIG. 12 .
[0039] The failure mode for each instrument control unit is the traditional hardware failure mode. It is all simulated by externally connected fault tree. Besides, in FIG. 13 a common type is used to represent the development mode for the fault tree for each instrument control unit. In addition to the spontaneous hardware failure for instrument control unit itself, there are also failure modes indirectly caused by foreign support system like power and air conditioning. Further, the common cause failure as a critical cause to system failure is also simulated in the developed standard fault tree. According to the design concepts for the digital instrument control for the nuclear power plant with advanced boiling water reactor, the essential common cause failure mainly includes the following reasons:
[0040] 1. Several detection units (DU) for the same type or identical signal detection fail at the same time due to design flaw, poor environment for equipment location, poor maintenance or incorrect calibration.
[0041] 2. Several data trip units (DTU) for verifying signals fail at the same time due to software design flaw, poor database or maintenance.
[0042] 3. Several network units (NU) for massive signal transmission fail at the same time due to software design flaw, failure for network system to support simultaneous signal transmission needs or poor maintenance.
[0043] 4. Several logic-processing units (LPU) for signal logic operation fail at the same time due to software design flaw or poor maintenance.
[0044] According to the above reasons for common cause failure, in the standard fault tree simulation is conducted for common cause failure mode with focus on measurement unit, data trip unit, network unit and logic processing unit, while other instrument control units do not simulate common cause failure. The following briefly describes the characteristics for each operation mode and important subjects for the development of standard fault tree.
[0045] Mode 1 : Automatic actuation equipment for single measurement unit
[0046] The operation process as shown in FIG. 1 is mainly for actuation of supporting equipments to non-safety or safety related equipments. It is the instrument control design without fault tolerance. After the analog signal from single measurement unit is converted to digital signal by the signal conversion unit and input to data trip unit to verify with the setting. Then the data trip unit outputs trip signals to the designated signal conversion unit to the specific equipment. The digital signal is converted to analog signal and output to the equipment actuation unit to actuate the equipment. The developed fault tree is shown in FIG. 7 . Since it is serial linear process, the failure of any unit will cause the failure of the entire instrument control process. Mode 1 only has single signal measurement unit and therefore does not simulate common cause failure for measured signals.
[0047] Mode 2 : Multiple measurement unit after logic operation automatically actuates multiple equipments
[0048] The operation process as shown in FIG. 2 is mainly used for safety related equipment. To prevent unnecessary action due to failures for some measurement units or data trip units, the measurement signals from several different measurement units of the same design are concentrated in the logic-processing unit for logic operation. With fault tolerance, the logic-processing unit undergoes logic operation and outputs single or multiple equipment operation signals. The signals are transmitted to the signal conversion unit through the network unit. The input digital signal is converted to analog signal and then input to the equipment actuation unit to actuate the equipment. The operation for the safety related equipments of the nuclear power plant with advanced boiling water reactor is handled by four independent instrument control divisions. Signal measurement, conversion and transmission are all conducted by the specific independent division. When the logic-processing unit is undergoing logic operation, it adopts two-out-of-four fault-tolerant strategy. It means it is not until at least two divisions input trip signals, the logic-processing unit will output equipment operation signal. In the development for the standard fault tree as shown in FIG. 8A˜8E , the fault-tolerant strategy should be changed and therefore it is not until at least three divisions have fault the logic processing unit will output equipment operation signals. The standard fault tree for mode 2 is developed with focus on unit E failure. Since unit E belongs to division I (DIV I), after the operation signal is processed and output by the logic processing unit in DIV I, the logic units in other divisions (DIV II˜DIV IV) also process and output the signals that are verified and come from their own measurement unit. In the simulation of common cause failure, measurement unit, data trip unit, network unit and logic processing unit are involved. For failure of other units (unit F˜unit J), except for the use of their own designated signal conversion unit and equipment actuation unit, they have the same signal source and the simulation mode for common cause failure as unit E.
[0049] Mode 3 : Mechanical operation panel to actuate single equipment
[0050] The operation process is shown in FIG. 3 . When the operator presses the button or turns the knob on the operation panel, the corresponding mechanical signal generation unit will output a digital signal and transmit the signal through the network unit to the signal conversion unit. Then the digital signal will be converted to analog signal and input to the equipment actuation unit to actuate the equipment. The developed standard fault tree is shown in FIG. 9 . Since it is serial linear process, the failure of any unit will cause the failure of the entire instrument control process. Since the equipment actuation relies on manual operation by the operator, the fault tree also includes the failure mode for manual operation by the operator.
[0051] Mode 4 : Mechanical operation panel to actuate multiple equipments
[0052] The operation process is shown in FIG. 4 . When the operator presses the button or turns the knob on the operation panel, the corresponding mechanical signal generation unit will output a digital signal. Since it is to actuate multiple equipments, the output signal is transmitted to the corresponding logic-processing unit, through which multiple equipment signals are output. Through network unit, the signals are transmitted to the designated signal conversion unit. After the digital signals are converted to analog signals, they are output to the equipment actuation unit to actuate the equipment. Since the fault tree uses equipment failure as top event, the developed standard fault tree as shown in FIG. 10 is also a serial linear process. The failure of any unit will cause the failure of the entire instrument control process. Since the equipment actuation relies on manual operation by the operator, the fault tree also includes the failure mode for manual operation by the operator. Since the standard fault tree in mode 4 is developed with focus on unit A failure, for failure of other units (unit B˜unit F), except for the use of their own designated signal conversion unit and equipment actuation unit, they have the same signal source and the simulation mode for common cause failure as unit A.
[0053] Mode 5 : Touch screen to actuate single system
[0054] The operation process is shown in FIG. 5 . When the operator touches and makes selection on the selection menu, the screen touch signal generation unit will output the corresponding digital signal to the signal conversion unit through the network unit, and then the digital signal will be converted to analog signal and output to the equipment actuation unit to actuate the equipment. The developed standard fault tree is shown in FIG. 11 . Since it is serial linear process, the failure of any unit will cause the failure of the entire instrument control process. Since the equipment actuation relies on manual operation by the operator, the fault tree also includes the failure mode for manual operation by the operator.
[0055] Mode 6 : Touch screen display to actuate multiple equipments
[0056] The operation process is shown in FIG. 6 . When the operator touches and makes selection on the selection menu, the screen touch signal generation unit will output the corresponding digital signal. Since it is to actuate multiple equipments, the signal is output to the corresponding logic-processing unit, which will output multiple equipment operation signals through the network unit to their own designated signal conversion unit. After the digital signal is converted to analog signal, it is output to the equipment actuation unit to actuate the equipment. Since the fault tree uses equipment failure as top event and the developed standard fault tree as shown in FIG. 12 also belongs to a serial linear process, the failure of any unit will cause the failure of the entire instrument control process. Since the equipment actuation relies on manual operation by the operator, the fault tree also includes the failure mode for manual operation by the operator. The standard fault tree for mode 6 is developed with focus on unit A failure. For failure of other units (unit B˜unit F), except for the use of their own designated signal conversion unit and equipment actuation unit, they have the same signal source and the simulation mode for common cause failure as unit A.
[0057] The establishment of the fault tree for equipment operation is based on the above eight instrument control units and six standard digital instrument control processes, which all function by splitting signal source and connecting to standard fault tree to build the fault tree for the nuclear power plant with boiling water reactor that involves complicated operation signals. The establishment procedures are described as follows:
[0058] Step 1. Analyze signal source for equipment operation With the instrument control logic diagram when analysis is conducted for signal source for equipment operation for the advanced boiling water reactor that not only involves signals for traditional automatically and manually operated single equipment but also automatic and manual signals to simultaneously operate multiple equipments, it is necessary to summarize and structure all the signals for the target equipments in the same system in details.
[0059] Step 2. Build process flow diagram for operation signal
[0060] After summarizing and structuring all the operation signals for the target equipments, the first thing necessary is to build the process flow diagram for all equipments to clarify the details with the generation and transmission of signals associated with each instrument control unit. All the instrument control units in the process flow control diagram should correspond to the above eight standard instrument control units. FIG. 14 shows the signal process flow diagram for all target equipments in a single system in a nuclear power plant with advanced boiling water reactor. The system includes seven equipments (EAU- 1 ˜EAU- 7 responsible for actuation) that participate in the analysis. Each equipment has its own signal source. There are seven sources of signals to actuate the seven equipments. Water level detection unit, first pressure detection unit and second pressure detection unit provide automatic operation signals. The signals from these units will be sent to different logic processing units (LPU- 1 , LPU- 2 ) for logic operation. Upon meeting the preset operation conditions for each equipment, the logic-processing unit will generate equipment operation signals that enable multiple equipment operation. There are four sources for manually generated operation signals. The manual signal from the mechanical signal generation unit MSGU- 1 can go through LPU- 1 and LPU- 2 and simultaneously handle multiple equipment operation. The manual signal from the mechanical signal generation unit MSGU- 2 is directly transmitted through hard wire to the equipment end. The manual signals from video signal generation units, VSGU- 1 and VSGU- 2 , have different functions. VSGU- 1 and MSGU- 1 have the same function, complimentary to each other as backup signal generation unit. The signal from VSGU- 2 can only operate one equipment at a time.
[0061] FIG. 14 clearly shows that a single instrument control module can be designed to handle multiple signal logic processing or transmission. NU- 1 from the figure, as an example of network unit, is responsible for transmitting not only detection unit signals but also automatic and manual operation signals for equipment operation. Therefore, the establishment of a detailed system signal process flow diagram not only helps check the rationality for signal transmission and logic operation but also facilitates simulate common cause failure in the fault tree analysis.
[0062] Step 3. Split operation signal source
[0063] After completion of the signal process flow diagram for system instrument operation, it is to split all the signal sources into an independent typical digital instrument control process based on the previously mentioned eight instrument control units and six typical digital instrument control flow processes. All the operation signals in FIG. 14 , as an example, can be split into 12 signal flow processes, including (1) 2 automatic operation signal flow processes provided by water-level detection unit, (2) 2 automatic operation signal flow processes provided by the first pressure detection unit, (3) 2 automatic operation signal flow processes provided by the second pressure detection unit, (4) 2 manual operation signal flow processes provided by MSGU- 1 , (5) 1 manual operation signal flow processes provided by MSGU- 2 , (6) 2 manual operation signal flow processes provided by VSGU- 1 , (7) 1 manual operation signal flow process provided by VSGU- 2 . After splitting, it is necessary to match all the signal flow processes to the six modes from FIG. 1 to FIG. 6 .
[0064] Step 4. Select and revise standard fault tree
[0065] After splitting in Step 3 for system equipment operation signals, every signal flow process can match one of the six modes. Each signal flow process should be revised by the corresponding standard fault tree. The instrument control units in an actual flow process are used to revise the standard fault tree. In revising fault tree, special attention shall be paid to the common instrument control unit shared by different signal sources. The common units shall use the same basic event name in different standard fault tree. Next, the signal logic operation in the fault tree shall select the suitable logic gate for actual design.
[0066] With the system instrument control flow process in FIG. 14 as an example, the manual operation signal flow process provided by the water-level detection unit, first pressure detection unit and second pressure detection unit can be classified as the mode 2 process in FIG. 2 ; the manual operation signal flow process provided by MSGU- 1 can be classified as the mode 4 process in FIG. 4 ; the manual operation signal flow process provided by MSGU- 2 can be classified as the mode 3 process in FIG. 3 ; the manual operation signal flow process provided by VSGU- 1 can be classified as the mode 6 process in FIG. 6 ; the manual operation signal flow process provided by VSGU- 2 can be classified as the mode 5 process in FIG. 5 . In revising fault tree, special attention shall be paid to the common instrument control units such as NU, DTU and LPU shared by different signal sources. The common units shall use the same basic event name in different standard fault tree. Next, regarding the signal logic operation for the three detection units in the fault tree, it adopts two-out-of-four fault-tolerant design strategy and three-out-of-four logic gate.
[0067] Step 5. Link standard fault tree
[0068] After completion of the fault tree for all signal sources, it is to link the fault tree to establish the specific fault tree to specific equipment operation. For specific equipment in the system, it is to select all the signal sources on the signal flow process diagram to operate the specific equipment, and then link all the corresponding standard fault trees into the fault tree for the specific equipment operation.
[0069] With the EAU- 1 ˜EAU- 7 actuated equipments in FIG. 14 as example, EAU- 2 and EAU- 3 can accept all automatic or manual operation signals in the figure. The difference is that EAU- 2 and EAU- 3 receive the operation signal from different logic processing units, LPU- 1 and LPU- 2 . EAU- 7 cannot be operated by the automatic signals in the figure and is manually operated by the signals from MSGU- 2 or VSGU- 2 . | The invention relates to the fault tree analysis system for a nuclear power plant with advanced boiling water reactor. The full digital instrument control system uses six different modes to simulate the transmission of the digital signals and the analog signals from the detection units. It is to develop the fault tree for various signal transmission modes to support the nuclear power plant in probabilistic risk assessment (PRA) and meet requirements for simulated signal detection, transmission, logic operation and equipment actuation. Thus, the digital instrument control flow process can fit into PRA model and properly reflect its importance in risk assessment. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of PCT International Patent Application No. PCT/EP02/04942, filed on May 3, 2002, designating the United States of America, and published, in English, as PCT International Publication No. WO 02/090551 A2 on Nov. 14, 2002, the contents of the entirety of which are incorporated herein by this reference.
TECHNICAL FIELD
[0002] The invention relates to a recombinant Lactococcus strain, with environmentally limited growth and viability. More particularly, it relates to a recombinant Lactococcus that can only survive in a medium, where well-defined medium compounds are present. A preferred embodiment is a Lactococcus that may only survive in a host organism, where the medium compounds are present, but cannot survive outside the host organism in an absence of the medium compounds. Moreover, the Lactococcus can be transformed with prophylactic and/or therapeutic molecules and can, as such, be used to treat diseases such as inflammatory bowel diseases.
BACKGROUND
[0003] Lactic acid bacteria have long been used in a wide variety of industrial fermentation processes. They have generally-regarded-as-safe (“GRAS”) status, making them potentially useful organisms for the production of commercially important proteins. Indeed, several heterologous proteins, such as Interleukin-2, have been successfully produced in Lactococcus spp (Steidler et al., 1995). It is, however, undesirable that such genetically modified microorganisms survive and spread into the environment.
[0004] To avoid unintentional release of genetically modified microorganisms, special guidelines for safe handling and technical requirements for physical containment are used. Although this may be useful in industrial fermentations, the physical containment is generally considered as insufficient, and additional biological containment measures are taken to reduce the possibility of survival of the genetically modified microorganism in the environment.
[0005] Biological containment is extremely important in cases where physical containment is difficult or even inapplicable. This is, amongst others, the case in applications where genetically modified microorganisms are used as live vaccines or as a vehicle for delivery of therapeutic compounds. Such applications have been described, for example, in PCT. International Publication Number WO 97/14806, which discloses the delivery of biologically active peptides, such as cytokines, to a subject by recombinant noninvasive or nonpathogenic bacteria. Further, PCT International Publication Number WO 96/11277 describes the delivery of therapeutic compounds to an animal or human by administering a recombinant bacterium encoding a therapeutic protein. Steidler et al. (2000) describe the treatment of colitis by administration of a recombinant Lactococcus lactis secreting Interleukin-10. Such a delivery may indeed be extremely useful to treat a disease in an affected human or animal, but the recombinant bacterium may act as a harmful and pathogenic microorganism when it enters a nonaffected subject, and an efficient biological containment that avoids such unintentional spreading of the microorganism is needed.
[0006] Biological containment systems for host organisms may be passive and based on a strict requirement of the host for a specific growth factor or a nutrient that is not present or is present in low concentrations in the outside environment. Alternatively, it may be active and, based on so-called suicidal genetic elements in the host, wherein the host is killed in the outside environment by a cell-killing function, encoded by a gene that is under the control of a promoter only being expressed under specific environmental conditions.
[0007] Passive biological containment systems are well known in microorganisms such as Escherichia coli or Saccharomyces cerevisiae. Such E. coli strains are disclosed, for example, in U.S. Pat. No. 4,190,495. Also, PCT International Publication Number WO 95/10621 discloses lactic acid bacterial suppressor mutants and their use as means of containment in lactic acid bacteria, but in that case, the containment is on the plasmid level, rather than on the level of the host strain and it stabilizes the plasmid in the host strain, but does not provide containment for the genetically modified host strain itself.
[0008] Active suicidal systems have been described by several authors. Such systems consist of two elements: a lethal gene and a control sequence that switches on the expression of the lethal gene under nonpermissive conditions. For example, PCT International Publication Number WO 95/10614 discloses the use of a cytoplasmatically active truncated and/or mutated Staphylococcus aureus nuclease as a lethal gene. PCT International Publication Number WO 96/40947 discloses a recombinant bacterial system with environmentally limited viability, based on the expression of either an essential gene, expressed when the cell is in the permissive environment and not expressed or temporarily expressed when the cell is in the nonpermissive environment, and/or a lethal gene, wherein expression of the gene is lethal to the cell and the lethal gene is expressed when the cell is in the nonpermissive environment but not when the cell is in the permissive environment. PCT International Publication Number WO 99/58652 describes a biological containment system based on the relE cytotoxin. However, most systems have been elaborated for Escherichia coli (Tedkin et al., 1995; Knudsen et al., 1995; Schweder et al., 1995) or for Pseudomonas (Kaplan et al., 1999; Molino et al., 1998). Although several of the containment systems theoretically can by applied to lactic acid bacteria, no specific biological containment system for Lactococcus has been described that allows the usage of a self-containing and transformed Lactococcus to deliver prophylactic and/or therapeutic molecules in order to prevent and/or treat diseases.
DISCLOSURE OF THE INVENTION
[0009] The invention includes a suitable biological containment system for Lactococcus. A first aspect of the invention is an isolated strain of Lactococcus sp. comprising a defective thymidylate synthase gene.
[0010] Another aspect of the invention is the use of a strain according to the invention as a host strain for transformation, wherein the transforming plasmid does not comprise an intact thymidylate synthase gene.
[0011] Still another aspect of the invention is a transformed strain of Lactococcus sp. according to the invention, comprising a plasmid that does not comprise an intact thymidylate synthase gene. Another aspect of the invention relates to a transformed strain of Lactococcus sp. comprising a gene or expression unit encoding a prophylactic and/or therapeutic molecule such as Interleukin-10. Consequently, the present invention also relates to the usage of a transformed strain of Lactococcus sp. to deliver prophylactic and/or therapeutic molecules and, as such, to treat diseases. Methods to deliver the molecules and methods to treat diseases such as inflammatory bowel diseases are explained in detail in PCT International Publication Numbers WO 97/14806 and WO 00/23471 to Steidler et al. and in Steidler et al. (Science 2000, 289:1352), the contents of all of which are incorporated herein by this reference.
[0012] Another aspect of the invention is a medical preparation comprising a transformed strain of Lactococcus sp., according to the invention.
[0013] The invention further demonstrates that the transformed strains surprisingly pass the gut at the same speed as the control strains, showing that their loss of viability indeed is not different from that of the control strains. However, once the strain is secreted in the environment, for example, in the feces, it is not able to survive any longer.
[0014] The transforming plasmid can be any plasmid, as long as it does not complement the thyA mutation. It may be a self-replicating plasmid that preferably carries one or more genes of interest and one or more resistance markers, or it may be an integrative plasmid. In the latter case, the integrative plasmid itself may be used to create the mutation by causing integration at the thyA site, whereby the thyA gene is inactivated.
BRIEF DESCRIPTION OF THE FIGURES
[0015] FIG. 1 : Map of the MG1363 thyA locus.
[0016] FIG. 2 : Schematic representation of the different expression modules as present on pOThy plasmids ands genomic integrants of hIL-10. Black parts represent original L. lactis MG1363 genetic information; white parts represent recombinant genetic information.
[0017] FIGS. 3 A and 3 B: PCR identification of Thy11 (Thy11 1.1 and Thy11 7.1 represent individually obtained, identical clones). Standard PCR reactions were performed by using aliquots of saturated cultures of the indicated strains as a source of a DNA template. FIG. 3A shows an agarose gel of the products of the indicated PCR reactions. FIG. 3B shows the positions at which primers attach in the thyA (1), upstream (2) or downstream (3) PCR's. Oligonucleotide primers used:
(1): ATgACTTACgCAgATCAAgTTTTT (SEQ ID NO:8 of the accompanying SEQUENCE LISTING, which is incorporated herein by this reference and TTAAATTgCTAAATCAAATTTCAATTg. (SEQ ID NO:9) (2): TCTgATTgAgTACCTTgACC (SEQ ID NO:10) and gCAATCATAATTggTTTTATTg (SEQ ID NO:11) (3): CTTACATgACTATgAAAATCCg (SEQ ID NO:12) and cTTTTTTATTATTAgggAAAgCA (SEQ ID NO:13).
[0021] FIGS. 4 A and 4 B: PCR identification of Thy11, Thy12, Thy15 and Thy16. Standard PCR reactions were performed by using three-day old colonies of the indicated strains as a source of DNA template. FIG. 4A shows the positions at which primers attach in the upstream (1), downstream (2) or thyA (3), PCRs. Oligonucleotide primers used:
(1): ATgACTTACgCAgATCAAgTTTTT (SEQ ID NO:8) and TTAAATTgCTAAATCAAATTTCAATTg (SEQ ID NO:9) (2): TCTgATTgAgTACCTTgACC (SEQ ID NO:10) and gCAATCATAATFFggTTTTATTg (SEQ ID NO:11) (3): CTTACATgACTATgAAAATCCg (SEQ ID NO:12) and cTTTTTTATTATTAgggAAAgCA. (SEQ ID NO:13)
FIG. 4B shows an agarose gel of the products of the indicated PCR reactions.
[0022] FIGS. 5 A and 5 B: Southern blot analysis of the indicated strains. Chromosomal DNA was extracted and digested with the indicated restriction enzymes. Following agarose gel electrophoresis, the DNA was transferred to a membrane and the chromosome structure around the thyA locus was revealed by use of DIG-labeled thyA or hIL-10 DNA fragments ( FIGS. 5A ). FIG. 5B shows a schematic overview of the predicted structure of the thyA locus in both MG1363 and Thy11.
[0023] FIG. 6A shows a schematic overview of part of the predicted structure of the L. lactis chromosome at the thyA locus in MG1363, Thy11, Thy12, Thy15 and Thy16. Numbers indicate base pairs. FIG. 6B illustrates a Southern blot analysis of the indicated strains. Chromosomal DNA was extracted and digested with NdeI and SpeI restriction enzymes. Following agarose gel electrophoresis, the DNA was transferred to a membrane and the chromosome structure around the thyA locus was revealed by use of DIG-labeled thyA or hIL-10 DNA fragments.
[0024] FIGS. 7 A and 7 B: Production of hIL-10. FIG. 7A shows a western blot revealed with anti-hIL-10 antiserum of culture supernatant and cell-associated proteins of the indicated strains. FIG. 7B shows quantification (by ELISA) of hIL-10 present in the culture supernatant.
[0025] FIGS. 8 A and 8 B: Production of hIL-10. FIG. 8A shows quantification (by ELISA) of hIL-10 present in the culture supernatant of the indicated strains. FIG. 8B shows a western blot revealed with anti-hIL-10 antiserum of culture supernatant proteins of the indicated strains.
[0026] FIG. 9 : Production of hIL-10 by the L. lactis strains LL108 carrying pOThy11, pOThy12, or pOThy16. Quantification (by ELISA) of hIL-10 present in the culture supernatant of the indicated strains is shown. The N-terminal protein sequence of the recombinant hIL-10 was determined by Edman degradation and was shown to be identical to the structure as predicted for the mature, recombinant hIL-10. The protein showed full biological activity.
[0027] FIGS. 10 A and 10 B: Growth rate of the indicated strains in GM17 containing 100 μ/ml (T100), 50 μ/ml (T50), 25 μ/ml (T25), or no (T0) extra thymidine and possibly supplemented with 5 μ/ml of erythromycin (E). Saturated overnight cultures (prepared in T50) were diluted 1:100 in the indicated culture media. FIG. 10A shows the kinetics of absorbance accumulation. FIG. 10B shows the kinetics of the number of colony-forming units (cfu) per ml of culture.
[0028] FIG. 11 : Growth rate of MG1363 and Thy12 in thymidine-free medium (TFM). TFM was prepared by growing L. lactis Thy12 bacteria in GM17, removing the bacteria by subsequent centrifugation and filtration on a 0.22 μm pore size filter, adjusting the pH to 7.0 and autoclaving. MG1363 and Thy12 bacteria were collected from an overnight culture in GM17 or GM17+50 μg/ml of thymidine, respectively, and washed in M9 buffer (6 g/l Na 2 HPO 4 , 3 g/l KH 2 PO 4 , 1 g/l NH 4 Cl, 0.5 g/l NaCl in water). The suspensions of both were either diluted in TFM or TFM supplemented with 50 μg/ml of thymidine (T50). CFU counts were determined at different time points: t=0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 20 hours. This shows that Thy12 viability is severely impaired in the absence of thymidine.
[0029] FIG. 12 : Intestinal passage and viability: L. lactis MG1363 was transformed with the plasmid pLET2N, which carries a chloramphenicol (Cm) resistance marker. L. lactis Thy12 was transformed with the plasmid pT1NX, which carries an erythromycin (Em) resistance marker. Of both strains, 10 9 bacteria were resuspended in BM9 (6 g/l Na 2 HPO 4 , 3 g/l KH 2 PO 4 , 1 g/l NH 4 Cl, 0.5 g/l NaCl in 25 mM NaHCO 3 +25 mM Na 2 CO 3 ), mixed and inoculated in three mice at t=0 h. Feces were collected at the time intervals −1 to 0, 0 to 1, 1 to 2, 2 to 3, 3 to 4, 4 to 5, 5 to 6, 6 to 7, 7 to 8, 8 to 9, 9 to 10 and 10 to overnight. All samples were resuspended in isotonic buffer and appropriate dilutions were plated on GM 17 (M1 7 medium, Difco, St. Louis, Mo., supplemented with 0.5% glucose) plates containing either Cm, Em or Em+50 μg/ml thymidine. Colony-forming units for the different plates are represented in the graph.
DETAILED DESCRIPTION OF THE INVENTION
[0030] As previously identified, the invention includes a suitable biological containment system for Lactococcus. In one aspect, the invention is an isolated strain of Lactococcus sp. comprising a defective thymidylate synthase gene. Preferably, the defective thymidylate synthase gene is inactivated by gene disruption. Even more preferably, the Lactococcus sp. is Lactococcus lactis. A special embodiment is a Lactococcus sp. strain, preferably Lactococcus lactis, more preferably a Lactococcus lactis MG1363 derivative, wherein the thymidylate synthase gene has been disrupted and replaced by an Interleukin-10 expression unit. The Interleukin-10 expression unit is preferably, but not limited to, a human Interleukin-10 expression unit or gene encoding for human Interleukin-10.
[0031] The Lactococcus lactis subsp. lactis thymidylate synthase gene (thyA) has been cloned by Ross et al. (1990a). Its sequence is comprised in SEQ ID NO:3 and SEQ ID NO:5. European Patent Application Publication Number 0406003 discloses a vector devoid of antibiotic resistance and bearing a thymidylate synthase gene as a selection marker; the same vector has been described by Ross et al. (1990b). However, this vector could not be used in a Lactococcus lactis strain due to the lack of a suitable thyA mutant that has never been described. The present invention discloses how to construct such a mutant by gene disruption using homologous recombination in Lactococcus. In a preferred embodiment, the thyA gene is disrupted by a functional human Interleukin-10 expression cassette. However, it is clear that any construct can be used for gene disruption, as long as it results in an inactivation of the thyA gene or in an inactive thymidylate synthase. As a nonlimiting example, the homologous recombination may result in a deletion of the gene, in one or more amino acid substitutions that lead to an inactive form of the thymidylate synthase, or in a frame shift mutation resulting in a truncated form of the protein.
[0032] Such a Lactococcus sp. thyA mutant is very useful as a host strain for transformation in situations where more severe containment than purely physical containment is needed. Indeed, thyA mutants cannot survive in an environment without or with only a limited concentration of thymidine and/or thymine. When such a strain is transformed with a plasmid that does not comprise an intact thyA gene and cannot complement the mutation, the transformed strain will become suicidal in a thymidine/thymine-poor environment. Such a strain can be used in a fermentor as an additional protection for the physical containment. Moreover, the present invention discloses that such a strain is especially useful in cases where the strain is used as a delivery vehicle in an animal body. Indeed, when such a transformed strain is given, for example, orally to an animal—including humans—it survives in the gut, provided that a sufficiently high concentration of thymidine/thymine is present, and produces homologous and/or heterologous proteins, such as human Interleukin-10, that may be beneficial for the animal.
[0033] The invention further demonstrates that the transformed strains surprisingly pass the gut at the same speed as the control strains, showing that their loss of viability indeed is not different from that of the control strains. However, once the strain is secreted in the environment, for example, in the feces, it is not able to survive any longer.
[0034] The transforming plasmid can be any plasmid, as long as it does not complement the thyA mutation. It may be a self-replicating plasmid that preferably carries one or more genes of interest and one or more resistance markers, or it may be an integrative plasmid. In the latter case, the integrative plasmid itself may be used to create the mutation by causing integration at the thyA site, whereby the thyA gene is inactivated. Preferably, the active thyA gene is replaced by double homologous recombination by a cassette comprising the gene or genes of interest, flanked by targeting sequences that target the insertion to the thyA target site. It is of extreme importance that these sequences are sufficiently long and sufficiently homologous to integrate the sequence into the target site. Preferably, the targeting sequences include at least 100 contiguous nucleotides of SEQ ID NO:1 at one side of the gene of interest and at least 100 contiguous nucleotides of SEQ ID NO:2 at the other side. More preferably, the targeting sequences consist of at least 500 contiguous nucleotides of SEQ ID NO:1 at one side of the gene of interest and at least 500 contiguous nucleotides of SEQ ID NO:2 at the other side. Most preferably, the targeting sequences consist of SEQ ID NO:1 at one side of the gene of interest and SEQ ID NO:2 at the other side, or the targeting sequences consist of at least 100 nucleotides that are at least 80% identical, preferably 90% identical to a region of SEQ ID NO:1 at one side of the gene of interest and at least 100 nucleotides that are at least 80% identical, preferably 90% identical to a region of SEQ ID NO:2 at the other side of the gene of interest. Preferably, the targeting sequences consist of at least 500 nucleotides that are at least 80% identical, preferably 90% identical to a region of SEQ ID NO:1 at one side of the gene of interest and at least 500 nucleotides that are at least 80% identical, preferably 90% identical to a region of SEQ ID NO:2 at the other side of the gene of interest. Most preferably, the targeting sequences consist of at least 1000 nucleotides that are at least 80% identical, preferably 90% identical to a region of SEQ ID NO:1 at one side of the gene of interest and at least 1000 nucleotides that are at least 80% identical, preferably 90% identical to a region of SEQ ID NO:2 at the other side of the gene of interest. The percentage identity is measured with BLAST, according to Altschul et al. (1997). A preferred example of a sequence homologous to SEQ ID NO:1 is given in SEQ ID NO:7. For the purpose of the invention, SEQ ID NO:1 and SEQ ID NO:7 are interchangeable.
[0035] Transformation methods of Lactococcus are known to the person skilled in the art and include, but are not limited to, protoplast transformation and electroporation.
[0036] A transformed Lactococcus sp. strain according to the invention is useful for the delivery of prophylactic and/or therapeutic molecules and can be used in a pharmaceutical composition. The delivery of such molecules has been disclosed, as a nonlimiting example, in PCT International Publication Numbers WO 97/14806 and WO 98/31786. Prophylactic and/or therapeutic molecules include, but are not limited to, polypeptides such as insulin, growth hormone, prolactin, calcitonin, group 1 cytokines, group 2 cytokines and group 3 cytokines and polysaccharides such as polysaccharide antigens from pathogenic bacteria. A preferred embodiment is the use of a Lactococcus sp. strain according to the invention to deliver human Interleukin-10. This strain can be used in the manufacture of a medicament to treat Crohn's disease as indicated herein.
[0037] The invention is further explained with the use of the following illustrative examples.
EXAMPLES
[0038] From L. lactis MG1363 (Gasson, 1983) regions flanking the sequence according to Ross et al. (1 990a) have been cloned.
[0039] The knowledge of these sequences is of critical importance for the genetic engineering of any Lactococcus strain in a way as described below, as the strategy will employ double homologous recombination in the areas of 1000 bp at the 5′ end (SEQ ID NO:1) and 1000 bp at the 3′ end (SEQ ID NO:2) of thyA, the “thyA target.” These sequences are not available from any public source to date. These flanking DNA fragments have been cloned and their sequence has been identified. The sequence of the whole locus is shown in SEQ ID NO:3; a mutant version of this sequence is shown in SEQ ID NO:5. Both the 5′ and 3′ sequences are different from the sequence at GenBank AE006385 describing the L. lactis IL1403 sequence. (Bolotin, in press) or at AF336368 describing the L. lactis subsp. lactis CHCC373 sequence. From the literature, it is apparent that homologous recombination by use of the published sequences adjacent to thyA (Ross et al., 1990a) (86 bp at the 5′ end and 31 bp at the 3′ end) is virtually impossible due to the shortness of the sequences. Indeed, Biswas et al. (1993) describe a logarithmically decreasing correlation between the length of the homologous sequences and the frequency of integration. The sequences of L. lactis Thy 11, Thy 12, Thy 15 and Thy 16 at the thyA locus as determined in the present invention are given by SEQ ID NOS:19, 20, 21, 22 respectively.
[0040] The thyA replacement is performed by making suitable replacements in a plasmid-borne version of the thyA target, as described below. The carrier plasmid is a derivative of pORI19 (Law et al., 1995), a replication-defective plasmid, which only transfers the erythromycin resistance to a given strain when a first homologous recombination, at either the 5′ 1000 bp or at the 3′ 1000 bp of the thyA target. A second homologous recombination at the 3′ 1000 bp or at the 5′ 1000 bp of the thyA target yields the desired strain.
[0041] The thyA gene is replaced by a synthetic gene encoding a protein which has the L. lactis Usp45 secretion leader (van Asseldonk et al., 1990) fused to a protein of an identical amino-acid sequence when: (a) the mature part of human-Interleukin 10 (hIL-10) or (b) the mature part of hIL-10 in which proline at position 2 has been replaced with alanine or (c) the mature part of hIL-10 in which the first two amino acids have been deleted; (a), (b) and (c) are called hIL-10 analogs, the fusion products are called Usp45-hIL-10.
[0042] The thyA gene is replaced by an expression unit comprising the lactococcal P1 promoter (Waterfield et al., 1995), the E. coli bacteriophageT7 expression signals, putative RNA stabilizing sequence and modified gene10 ribosomal binding site (Wells and Schofield, 1996).
[0043] At the 5′ end, the insertion is performed in such way that the ATG of thyA is fused to the P1-T7Usp45-hIL-10 expression unit.
5′ agataggaaaatttc atg acttacgcagatcaagttttt...thyA wild-type (SEQ ID NO:27) gattaagtcatcttacctctt...P1-T7-usp45-hIL10 (SEQ ID NO:14) 5′ agataggaaaatttc atg gattaagtcatcttacctctt...thyA − , P1-T7-usp45-hIL10 (SEQ ID NO:15)
[0044] Alternatively, at the 5′ end, the insertion is performed in such a way that the thyA ATG is not included:
5′ agataggaaaatttcacttacgcagatcaagttttt...thyA wild-type (SEQ ID NO:28) gattaagtcatcttacctctt...P1-T7-usp45-hIL10 (SEQ ID NO:14) 5′ agataggaaaatttcgattaagtcatcttacctctt...thYA − ,P1-T7-usp45-hIL10 (SEQ ID NO:16)
[0045] Alternatively, at the 5′ end, the insertion is performed in such a way that the thyA promoter (Ross, 1990 a) is not included:
5′ tctgagaggttattttgggaaatacta ttgaac catatcgaggtgtgtgg tataat gaagggaattaaaaaa (SEQ ID NO:29) gata ggaa aatttc atg ...thyA wild-type gattaagtcatcttacctctt...P1-T7-usp45hIL10 (SEQ ID NO:29) 5′ tctgagaggttattttgggaaatactagattaagtcatcttacctctt...thyA − ,P1-T7-usp45-hIL10 (SEQ ID NO:14)
[0046] At the 3′ end, an ACTAGT Spel restriction site was engineered immediately adjacent to the TAA stop codon of the usp45-hIL-10 sequence. This was ligated in a TCTAGA XbaI restriction site, which was engineered immediately following the thyA stop codon
aaaatccgtaac taa ctagt 3′...usp45-hIL10 (SEQ ID NO:30) gatttagcaatt taa attaaattaatctataagtt 3′...thyA-wild-type (SEQ ID NO:31) tctaga attaatctataagttactga 3′...engineered thyA target (SEQ ID NO:32) aaaatccgtaac taa ctaga attaatctataagttactga 3′...thyA − ,usp45-hIL10 (SEQ ID NO:18)
[0047] These constructs are depicted in FIG. 2 . The sequences of pOThy 11, pOThy12 pOThy15 and pOThy16 are given by SEQ ID NOs: 23, 24, 25, and 26 respectively. The resulting strains are thyA deficient, a mutant not yet described for L. lactis. It is strictly dependent upon the addition of thymine or thymidine for growth.
[0048] The map of the deletion, as well as the PCR analysis of all the isolates/mutants of the present invention, is shown in FIGS. 3A-4B . The presence of the thymidylate synthase and the Interleukin 10 (IL-10) gene in the wild-type strain and in the independent isolates/mutant was analyzed by Southern analysis as shown in FIGS. 5A-6B . The region around the inserted hIL-10 gene was isolated by PCR and the DNA sequence was verified. The structure is identical to the predicted sequence.
[0049] Human Interleukin-10 (hIL-10) production in the mutants was checked by western blot analysis and compared with the parental strain, transformed with pTREX1 as negative control, and the parental strain, transformed with the IL10-producing plasmid pT1HIL10apxa as a positive control ( FIG. 7A ). The concentration in the culture supernatant was quantified using ELISA. As shown in FIG. 7B , both isolates of the mutant produce a comparable, significant amount of hIL-10, be it far less than the strain, transformed with the nonintegrative plasmid pT1HIL10apxa. FIGS. 8A and 8B further demonstrate that all mutants produce a significant amount of hIL-10.
[0050] FIG. 9 shows the production of hIL-10 by the L. lactis strains LL108 carrying pOThy11, pOThy12, or pOThy16. Quantification (by ELISA) of hIL-10 present in the culture supernatant of the indicated strains is shown. The N-terminal protein sequence of the recombinant hIL-10 was determined by Edman degradation and was shown to be identical to the structure as predicted for the mature, recombinant hIL-10. The protein showed full biological activity. LL108 is an L. lactis strain carrying a genomic integration of the repA gene, required for replication ofpORI19 derived plasmids such as pOThy11, pOThy12, pOThy15 or pOThy16. This strain was kindly donated by Dr. Jan Kok, University of Groningen, The Netherlands. The plasmids pOThy11, pOThy12, pOThy15 and pOThy16 carry the synthetic human IL-10 gene in different promoter configurations (see FIG. 2 ), flanked by approximately 1 kB of genomic DNA derived from the thyA locus, upstream and downstream from thyA. These plasmids were used for the construction of the genomic integration as described.
[0051] The effect of the thymidylate synthase deletion on the growth in thymidine less and thymidine-supplemented media was tested; the results are summarized in FIGS. 10 and 11 . An absence of thymidine in the medium strongly limits the growth of the mutant and even results in a decrease of colony-forming units after four hours of cultivation. The addition of thymidine to the medium results in an identical growth curve and amount of colony-forming units, compared to the wild-type strain, indicating that the mutant does not affect the growth or viability in thymidine-supplemented medium. FIG. 11 clearly demonstrates that Thy12 viability is severely impaired in the absence of thymidine.
[0052] FIG. 12 finally shows that L. lactis Thy12 passes through the intestine of the mice at the same speed as MG1363. Loss of viability does not appear to differ between Thy12 and MG1363. Thy12 appears fully dependent on thymidine for growth, indicating that no Thy12 bacteria had taken up a foreign thyA gene.
References
[0000]
Altschul, S. F., Madden, T. L., Schaffer, A. A., Zhang, J., Zhang, Z., Miller, W. and Lipman D. J. (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res. 25, 3389-3402.
Biswas, I., Gruss, A., Ehrlich, S. D. et al. (1993) High-efficiency gene inactivation and replacement system for gram-positive bacteria. J. Bacteriol. 175, 3628-3635.
Gasson, M. J. (1983). Plasmid complements of Streptococcus lactis NCDO 712 and other lactic streptococci after protoplast-induced curing. J Bacteriol. 154, 1-9.
Kaplan, D. L., Mello, C., Sano, T., Cantor, C. and Smith, C. (1999). Streptavidin-based containment system for genetically engineered microorganisms. Biomol. Eng. 31, 135-140.
Knudsen, S., Saadbye, P., Hansen, L. H., Collier, A., Jacobsen, B. L., Schlundt, J. And Karlstrom, O. H. (1995). Development and testing of improved suicide functions for biological containment of bacteria. Appl. Environ. Microbiol. 61, 985-991.
Law, J., Buist, G., Haandrikman, A. et al. (1995). A system to generate chromosomal mutations in Lactococcus lactis which allows fast analysis of targeted genes. J Bacteriol. 177, 7011-7018.
Molina, L., Ramos, C., Ronchel, M. C., Molin, S. and Ramos, J. L. (1998). Construction of an efficient biologically contained Pseudomonas putida strain and its survival in outdoor assays. Appl. Environ. Microbiol. 64, 2072-2078.
Ross, P., O'Gara, F. and Condon, S. (1990a). Cloning and characterization of the thymidylate synthase gene from Lactococcus lactis subsp. Lactis. Appl. Environ. Microbiol. 56, 2156-2163.
Ross, P., O'Gara, F. and Condon, S. (1990b). Thymidylate synthase gene from Lactococcus lactis as a genetic marker: an alternative to antibiotic resistance. Appl. Environ. Microbiol 56, 2164-2169.
Schweder, T., Hofinann, K. And Hecker, M. (1995). Escherichia coli K12 relA strains as safe hosts for expression of recombinant DNA. Appl. Environ. Microbiol. 42, 718-723.
Steidler, L., Hans, W., Schotte, L., Neirynck, S., Obermeier, F., Falk, W., Fiers, W. and Remaut, E. (2000). Treatment of murine colitis by Lactococcus lactis secreting Interleukin-10. Science 289, 1352-1355.
Steidler, L., Wells, J. M., Raeymaekers, A., Vandekerckhove, J., Fiers, W. And Remaut, E. (1995). Secretion of biologically active murine Interleukin-2 by Lactococcus lactis subsp. Lactis. Appl. Environ. Microbiol. 61, 1627-1629.
Tedin, K. Witte, A., Reisinger, G., Lubitz, W. and Basi, U. (1995). Evaluation of the E. coli ribosomal rrnB P1 promoter and phage derived lysis genes for the use in biological containment system: a concept study. J. Biotechnol. 39, 137-148.
van Asseldonk, M., Rutten, G., Oteman, M. et al. (1990). Cloning of usp45, a gene encoding a secreted protein from Lactococcus lactis subsp. lactis MG1363. Gene 95, 155-160.
Waterfield, N. R., Le Page, R. W., Wilson, P. W. et al. (1995) The isolation of lactococcal promoters and their use in investigating bacterial luciferase synthesis in Lactococcus lactis. Gene 165,9-15.
Wells, J. M. and Schofield, K. M. (1996) Cloning and expression vectors for Lactococci. Nato ASI series H98, 37-62. | The invention relates to a recombinant Lactococcus strain, with environmentally limited growth and viability. More particularly, it relates to a recombinant Lactococcus that can only survive in a medium, where well-defined medium compounds are present. A preferred embodiment is a Lactococcus that may only survive in a host organism, where such medium compounds are present, but cannot survive outside the host organism in the absence of such medium compounds. | 2 |
PRIORITY CLAIM
[0001] The following application is a continuation of and claims priority to U.S. patent application Ser. No. 11/745,390 filed May 7, 2007, which claims priority to and the benefit of U.S. Provisional Application Ser. No. 60/746,621 filed May 5, 2006, U.S. Provisional Application Ser. No. 60/861,406 filed Nov. 27, 2006, and U.S. Provisional Application Ser. No. 60/903,810 filed Nov. 27, 2006. Each of the foregoing applications are hereby incorporated by reference in their entirety as if fully set forth herein.
[0002] This application also a continuation-in-part of and claims priority to U.S. patent application Ser. No. 12/251,370 filed Oct. 14, 2008 and PCT Application Serial Number PCT/US08/79885 filed Oct. 14, 2008 both of which claim priority to and the benefit of U.S. Provisional Application Ser. No. 60/998,730 filed Oct. 11, 2007; U.S. Provisional Application Ser. No. 61/003,144 filed Nov. 13, 2007; U.S. Provisional Application Ser. No. 61/072,776 filed Apr. 1, 2008; and U.S. Patent Application Ser. No. 61/126,061 filed Apr. 29, 2008. This application also a continuation-in-part of and claims priority to U.S. patent application Ser. No. 12/192,919 filed Aug. 15, 2008 and PCT Application Serial Number PCT/US08/73401 filed Aug. 15, 2008 both of which claim priority to and the benefit of U.S. Provisional Application Ser. No. 60/965,067 filed Aug. 15, 2007 and U.S. Provisional Application Ser. No. 60/956,097 filed Aug. 15, 2007. This application is also a continuation-in-part of U.S. patent application Ser. No. 12/580,667 filed Oct. 16, 2009 which claims priority to and the benefit of U.S. Provisional Application Ser. No. 61/106,134 filed Oct. 16, 2008, U.S. Provisional Application Ser. No. 61/147,057 filed Jan. 23, 2009, and U.S. Provisional Application Ser. No. 61/241,132 filed Sep. 14, 2009. All of which are incorporated by reference in their entirety as if fully set forth herein.
COPYRIGHT NOTICE
[0003] This disclosure is protected under United States and International Copyright Laws. © 2006-2010 Visible Technologies. All Rights Reserved. A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure after formal publication by the USPTO, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
[0004] As used herein, the term “Consumer Generated Media” (hereinafter CGM) is a phrase that describes a wide variety of Internet web pages or sites, which are sometimes individually labeled as web logs or “blogs”, mobile phone blogs or “mo-blogs”, video hosting blogs or “vlogs” or “vblogs”, forums, electronic discussion messages, Usenet, message boards, BBS emulating services, product review and discussion web sites, online retail sites that support customer comments, social networks, media repositories, audio and video sharing sites/networks and digital libraries. Private non-Internet information systems can host CGM content as well, via environments like Sharepoint, Wiki, Jira, CRM systems, ERP systems, and advertising systems. Other acronyms that describe this space are CCC (consumer created content), WSM (weblogs and social media), WOMM (Word of Mouth Media) or OWOM, (online word of mouth), and many others.
[0005] As used herein, the term “Keyphrase” refers to a word, string of words, or groups of words with Boolean modifiers that are used as models for discovering CGM content that might be relevant to a given topic. Could also be an example image, audio file or video file that has characteristics that would be used for content discovery and matching.
[0006] As used herein, the term “Post” refers to a single piece of CGM content. This might be a literal weblog posting, a comment, a forum reply, a product review, or any other single element of CGM content.
[0007] As used herein, the term “Site” refers to an Internet site which contains CGM content.
[0008] As used herein, the term “Blog” refers to an Internet site which contains CGM content.
[0009] As used herein, the term “Content” refers to media that resides on CGM sites. CGM is often text, but includes audio files and streams (podcasts, mp3, streamcasts, Internet radio, etc.) video files and streams, animations (flash, java) and other forms of multimedia.
[0010] As used herein, the term “UI” refers to a User Interface, that users interact with computer software, perform work, and review results.
[0011] As used herein, the term “IM” refers to an Instant Messenger, which is a class of software applications that allow direct text based communication between known peers.
[0012] As used herein, the term “Thread” refers to an “original” post and all of the comments connected to it, present on a blog or forum. A discussion thread holds the information of content display order, so this message came first, followed by this, followed by this.
[0013] As used herein, the term “Permalink” refers to a URL which persistently points to an individual CGM thread
[0014] The Internet and other computer networks are communication systems. The sophistication of this communication has improved and the primary modes differentiated over time and technological progress. Each primary mode of online communication varies based on a combination of three basic values: privacy and persistence and control. Email as a communications medium is private (communications are initially exchanged only between named recipients), persistent (saved in inboxes or mail servers) but lacks control (once you send the message, you can't take it back, or edit it, or limit re-use of it). Instant messaging is private, typically not persistent (some newer clients are now allowing users to save history, so this mode is changing) and lacks control. Message boards are public (typically all members, and often all Internet users, can access your message) persistent, but lack control (they are typically moderated by a central owner of the board). Chat rooms are public (again, some are membership based) typically not persistent, and lack control.
[0000]
privacy
persistence
author control
Chat Rooms/IRC
no
no
no
Instant Messaging
yes
no
no
Forums
no
yes
no
Email
yes
yes
no
Blogs
no
yes
yes
social networks
yes/no
yes
yes
Second Life
yes
yes
yes+
[0015] Blogs and Social Networks are the predominant communications mediums that permit author control. By reducing the cost, technical sophistication, and experience required to create and administer a web site, blogs and other persistent online communication have given an unprecedented amount of editorial control to millions of online authors. This has created a unique new environment for creative expression, commentary, discourse, and criticism without the historical limits of editorial control, cost, technical expertise, or distribution/exposure.
[0016] There is significant value in the information contained within this public media. Because the opinions, topics of discussion, brands and celebrities mentioned and relationships evinced are typically totally unsolicited, the information presented, if well studied, represents an amazing new source of social insight, consumer feedback, opinion measurement, popularity analysis and messaging data. It also represents a fully exposed, granular network of peer and hierarchical relationships rich with authority and influence. The marketing, advertising, and PR value of this information is unprecedented.
[0017] This new medium represents a significant challenge for interested parties to comprehensively understand and interact with. As of Q1 2007 estimates for the number of active, unique online CGM sites (forums, blogs, social networks, etc.) range from 50 to 71 million, with growth rates in the hundreds of thousands of new sites per day. Compared to the typical mediums that PR, Advertising and Marketing businesses and divisions interact with (<1000 TV channels, <1000 radio stations, <1000 major news publications, <10-20 major pundits on any given subject, etc.) this represents a nearly 10,000-fold increase in the number of potential targets for interaction.
[0018] Businesses and other motivated communicators have come to depend on software that perform Business Intelligence, Customer Relationship Management, and Enterprise Resource Planning tasks to facilitate accelerated, organized, prioritized, tracked and analyzed interaction with customers and other target groups (voters, consumers, pundits, opinion leaders, analysts, reporters, etc.). These systems have been extended to facilitate IM, E-mail, and telephone interactions. These media have been successfully integrated because of standards (jabber, pop3, smtp, pots, imap) that require that all participant applications conform to a set data format that allows interaction with this data in a predictable way.
[0019] Blogs and other CGM generate business value for their owners, both on private sites that use custom or open source software to manage their communications, and for massive public hosts. Because these sites can generate advertising revenue, there is a drive by author/owners to protect the content on these sites, so readers/subscribers/peers have to visit the site, and become exposed to revenue generating advertising, in order to participate in/observe the communication. Because of this financial disincentive, there is no unifying standard for blogs which contains complete data. RSS and Atom feeds allow structured communication of some portion of the communication on sites, but are often very incomplete representations of the data available on a given site. Sites also protect their content from being “stolen” by automated systems with an array of CAPTCHAs, (“Completely Automated Public Turing test to tell Computers and Humans Apart”) email verification, mobile phone text message verification, password authentication, cookie tracking, Uniform Resource Locator (URL) obfuscation, timeouts and Internet Protocol (IP) address tracking.
[0020] The result is a massively diverse community that it would be very valuable to understand and interact with, which resists aggregation and unified interaction by way of significant technical diversity, resistance to complete information data standards, and tests that attempt to require one-to-one human interaction with content.
SUMMARY OF THE INVENTION
[0021] TruCast is a method for management, by way of gathering, storing, analyzing, tracking, sorting, determining the relevance of, visualizing, and/or responding to all available consumer generated media. Some examples of consumer generated media include web logs or “blogs”, mobile phone blogs or “mo-blogs”, forums, electronic discussion messages, Usenet, message boards, BBS emulating services, product review and discussion web sites, online retail sites that support customer comments, social networks, media repositories, and digital libraries. Any web hosted system for the persistent public storage of human commentary is a potential target for this method. The system is comprised of a coordinated software and hardware system designed to perform management, collection, storage, analysis, workflow, visualization, and response tasks upon this media. This system permits a unified interface to manage, target, and accelerate interactions within this space, facilitating public relations, marketing, advertising, consumer outreach, political debate, and other modes of directed discourse.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.
[0023] FIGS. 1A-1B shows an example system for consumer generated media reputation management; and,
[0024] FIG. 2 shows a method for consumer generated media reputation management;
[0025] FIG. 3 shows a incoming data from collection being delivered to an ingestion system in one embodiment;
[0026] FIG. 4 is a depiction of one embodiment of a CGM site discovery system;
[0027] FIG. 5 provides an overview of ingestion in one embodiment;
[0028] FIG. 6 shows manual scoring in one embodiment;
[0029] FIGS. 7-9 show the smooth transition between user scoring and automated scoring, in one embodiment;
[0030] FIG. 10 is a depiction of one embodiment of a CGM response engine;
[0031] FIGS. 11-13 show screen shots of a registration and response feature;
[0032] FIG. 14 shows an example screenshot of the TruCast Login Authentication screen;
[0033] FIG. 15 shows an example screenshot of a user interface homepage;
[0034] FIG. 16 shows an example screenshot of an account manager panel;
[0035] FIG. 17 shows an example screenshot of a user manager panel;
[0036] FIG. 18 shows an example screenshot of a topic manager panel;
[0037] FIG. 19 shows an example screenshot of a topic manager panel with the keyphrase tab activated;
[0038] FIG. 20 shows an example screenshot of a sorting manager;
[0039] FIG. 21 shows an example screenshot of the sorting manager with the user tab activated;
[0040] FIG. 22 shows an example screenshot of a scoring manager;
[0041] FIG. 23 shows an example screenshot of a scoring manager with a new topic creator screenshot activated;
[0042] FIG. 24 shows an example screenshot of a response manager;
[0043] FIG. 25 shows an example screenshot of an administrative queue;
[0044] FIG. 26 shows an example screenshot of a dashboard launcher;
[0045] FIG. 27 shows an example screenshot of an impact dashboard;
[0046] FIG. 28 shows an example screenshot of a sentiment dashboard;
[0047] FIG. 29 shows an example screen shot of a sentiment history dashboard;
[0048] FIG. 30 shows an example screenshot of an authority map dashboard;
[0049] FIG. 31 shows an example screenshot of a data drilldown dashboard;
[0050] FIG. 32 shows an example screenshot of an ecosystem map dashboard;
[0051] FIG. 33 shows an example screenshot of an ecosystem map zoom out view;
[0052] FIG. 34 shows an example screenshot of a sentiment summary;
[0053] FIG. 35 shows an example screenshot of a set of top lists;
[0054] FIG. 36 shows an example screenshot of reporting;
[0055] FIG. 37 shows an example screenshot of an aggregate performance dashboard; and
[0056] FIG. 38 shows a system overview in detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0057] FIG. 1A illustrates an example of a suitable computing system environment 100 on which an embodiment of the invention may be implemented. The computing system environment 100 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention. Neither should the computing environment 100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 100 .
[0058] Embodiments of the invention are operational with numerous other general-purpose or special-purpose computing-system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with embodiments of the invention include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed-computing environments that include any of the above systems or devices, and the like.
[0059] Embodiments of the invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Embodiments of the invention may also be practiced in distributed-computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed-computing environment, program modules may be located in both local- and remote-computer storage media including memory storage devices.
[0060] With reference to FIG. 1A , an exemplary system for implementing an embodiment of the invention includes a computing device, such as computing device 100 . In its most basic configuration, computing device 100 typically includes at least one processing unit 102 and memory 104 .
[0061] Depending on the exact configuration and type of computing device, memory 104 may be volatile (such as random-access memory (RAM)), non-volatile (such as read-only memory (ROM), flash memory, etc.) or some combination of the two. This most basic configuration is illustrated in FIG. 1A by dashed line 106 .
[0062] Additionally, device 100 may have additional features/functionality. For example, device 100 may also include additional storage (removable and/or non-removable) including, but not limited to, magnetic or optical disks or tape. Such additional storage is illustrated in FIG. 1A by removable storage 108 and non-removable storage 110 . Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Memory 104 , removable storage 108 and non-removable storage 110 are all examples of computer storage media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by device 100 . Any such computer storage media may be part of device 100 .
[0063] Device 100 may also contain communications connection(s) 112 that allow the device to communicate with other devices. Communications connection(s) 112 is an example of communication media. Communication media typically embodies computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio-frequency (RF), infrared and other wireless media. The term computer-readable media as used herein includes both storage media and communication media.
[0064] Device 100 may also have input device(s) 114 such as keyboard, mouse, pen, voice-input device, touch-input device, etc. Output device(s) 116 such as a display, speakers, printer, etc. may also be included. All such devices are well-known in the art and need not be discussed at length here.
[0065] Referring now to FIG. 1B , an embodiment of the present invention can be described in the context of an exemplary computer network system 200 as illustrated. System 200 includes an electronic client device 210 , such as a personal computer or workstation, that is linked via a communication medium, such as a network 220 (e.g., the Internet), to an electronic device or system, such as a server 230 . The server 230 may further be coupled, or otherwise have access, to a database 240 and a computer system 260 . Although the embodiment illustrated in FIG. 1B includes one server 230 coupled to one client device 210 via the network 220 , it should be recognized that embodiments of the invention may be implemented using one or more such client devices coupled to one or more such servers.
[0066] In an embodiment, each of the client device 210 and server 230 may include all or fewer than all of the features associated with the device 100 illustrated in and discussed with reference to FIG. 1A . Client device 210 includes or is otherwise coupled to a computer screen or display 250 . As is well known in the art, client device 210 can be used for various purposes including both network- and local-computing processes.
[0067] The client device 210 is linked via the network 220 to server 230 so that computer programs, such as, for example, a browser, running on the client device 210 can cooperate in two-way communication with server 230 . Server 230 may be coupled to database 240 to retrieve information therefrom and to store information thereto. Database 240 may include a plurality of different tables (not shown) that can be used by server 230 to enable performance of various aspects of embodiments of the invention. Additionally, the server 230 may be coupled to the computer system 260 in a manner allowing the server to delegate certain processing functions to the computer system.
[0068] In one embodiment, the methods and systems are implemented by a coordinated software and hardware computer system. This system is comprised of a set of dedicated networked servers controlled by TruCast. The servers are installed with a combination of commercially available software, custom configurations, and custom software. A web server is one of those modules, which exposes a web based client-side UI to customer web browsers. The UI interacts with the dedicated servers to deliver information to users. The cumulative logical function of these systems results in a system and method referred to as TruCast.
[0069] In alternate embodiments, the servers could be placed client side, could be shared or publicly owned, could be located together or separately. The servers could be the aggregation of non-dedicated compute resources from a Peer to Peer (P2P), grid, or other distributed network computing environments. The servers could run different commercial applications, different configurations with the same or similar cumulative logical function. The client to this system could be run directly from the server, could be a client side executable, could reside on a mobile phone or mobile media device, could be a plug-in to other Line of Business applications or management systems. This system could operate in a client-less mode where only Application Programming Interface (API) or eXtensible Markup Language (XML) or Web-Services or other formatted network connections are made directly to the server system. These outside consumers could be installed on the same servers as the custom application components. The custom server-side engine applications could be written in different languages, using different constructs, foundations, architectural methodologies, storage and processing behaviors while retaining the same or similar cumulative logical function. The UI could be built in different languages, using different constructs, foundations, architectural methodologies, storage and processing behaviors while retaining the same or similar cumulative logical function.
[0070] FIG. 2 shows a method for consumer generated media reputation management. The TruCast system can be broken down into elements, the elements are, but are not limited to the following: collection, ingestion, analysis, reporting and response.
[0071] Collection
[0072] In one embodiment, the Collection system gathers the majority of information about all CGM content online. This is a weighted, prioritized goal because TruCast functions in a weighted, prioritized way. This prioritization system is an optionally advantageous element of the collection system, called the Collection Manager. The Collection Manager receives input from internal and external sources about what sites have information of value, weights that information against a set of pre-described and manipulatable co-factors to allow tuning, and prioritizes the execution of collection against those sites.
[0073] In order to collect data from a blog site, an automated web scripting and parsing system called a robot is built. An individual “robot” is a sophisticated, coordinated script which informs a software engine of how to navigate, parse, and return web information. Every web site is comprised of code in one of several popular languages, which software applications called web browsers “render” or convert to a visually appealing “web site”. A robot, similar to a browser, interprets site code to render an output. The desired output is not the “web site” that a browser would create, but an XML document, with columns of information about the content stored on a given site. Because robots are accessing the code, and not the rendered page, they have access to markup structures in the code which identify where specific content of interest is stored within the code. Robots use navigation based on Document Object Model (DOM) trees, regular expression pattern matching, conditional parsing, pre-coded transformations, mathematical and logical rules, tags, comments, formatting, and probability statistics to extract the specific content TruCast, in one embodiment, uses from raw web site code. Functions which perform this parsing are abstracted and codified in the robot engine, which is instructed on specific actions by a specific robot script. In pseudo-code, a robot designed to gather all of the blog content on a wordpress site would be scripted thusly: Load X URL, read code until “<bodytext>” is found, return all text until “</bodytext>” is found. If it is found create row 1, store this text in column A row 1. Find link with the word “next” in it, follow this link. Read code until “<bodytext>” is found, return all text until “</bodytext>” is found. If it is found create row 2, store this text in column A row 2.
[0074] This is a clearly incomplete example, as a plurality of robots have the ability to gather and transform a very complete set of knowable information from every website visited, including the full body text, author's name, date of the post, permalink to the post, title of the post, it's position on the page, how many comments it has, the full information about those comments, including author, date, order, body, any hyperlinks, graphics, scripts, emoticons, or other multimedia files included in a post, comment or site. Robots can be designed to gather data from only an individual site, or made more general to accommodate variation amongst similar sites. Robots parse the gamut non-structured web site code into XML encoded text that meets a predefined data specification of the design. The system, in one embodiment, collects all posts, all comments, and all desired content from every page that a robot visits.
[0075] Robots are not limited to these methods for content parsing hierarchical temporal memory analysis, probability-based positive heuristics, and structural inference technologies can be used to make robots are capable of collecting information from a wider variety of sites.
[0076] Some sites have full-data RSS or Atom feeds (different than the typically truncated feeds), for which a specific set of robots exist. The system also has data vendors who deliver full-data feeds in several formats, these feeds are converted to the XML data spec by another class of robots. Robots are not limited to web content collection, but represent a scriptable system for parsing and transforming incoming and outgoing data based on pre-defined rules.
[0077] FIG. 3 depicts one embodiment of a CGM data collection system. In one embodiment, the first step of this system is to prioritize possible targets for collection. Inputs to this prioritization include, but are not limited to, sites specifically requested by customers ( 305 ) and the number of responses the system is written to a given site ( 310 ), the number of accounts that find content from this site relevant ( 315 ), the total count of relevant content available on the site ( 320 ), the date of the most recent post written on the site ( 325 ) and the historical performance of the system at gathering content from this site ( 330 ). The priority database maintains an updated list of co-factors which are calculated priorities for each site based on these inputs. When the Collection manager ( 340 ) determines that it has excess bandwidth/resources to execute more robots, it polls the priority database ( 335 ) to determine which robots ( 345 ) and then executes them. The collection manager also stores the records of robot activity so that it can add this information to the priority database ( 335 ). Robots, once launched by the Collection Manager, interface with their targets ( 350 ) to return XML-formatted CGM content to the Ingestion system ( 355 ).
[0078] FIG. 4 is a depiction of one embodiment of a CGM site discovery system. Site discovery is the process of finding the URLS of new CGM sites on the Internet. The coordination is performed by the Discovery Robot Manager ( 372 ). This system retains performance information of the three methods, and determines what percentage of available resources (cpu time, bandwidth) to spend running each of the three methods in order to discover the most new URLs possible. The Discovery Robot Manager receives input from the Discovery Targets DB ( 370 ) which stores all of the information to execute each of the three methods, most notably the URL targets for each method. This system is fed information from customer or internal research discovered URLs ( 362 ) URLs of known search engines ( 364 ) URLs found in the post bodies of CGM content ( 366 ) and the URLs of the directory pages for each of the major blog hosts ( 368 ). Each method uses this information and a script for web interaction, called a robot, to discover new CGM URLs. The first method is called the “Real Estate” method. When the Discovery Robot Manager ( 372 ) determines that it is efficient to do so, it will launch a Real Estate robot for a specific search engine ( 374 ), and supply it with a list of keywords from all account topics which is held in the Discovery Targets DB ( 370 ). This robot will visit the search engine and fill in the search form with each keyword, and gather, by way of regular expression pattern extraction, the URLs of the results from the first 4 pages of results. This information will be delivered in XML format to the de-duplicator ( 388 ), which will eliminate known URLs, and then be stored in the Collection Prioritization DB ( 390 ) for collection. The second method, Site Search, is very similar to the Real Estate method, uses the same robots, but behaves in a different way with different input. The Real Estate robots use keywords from the topics in the accounts. The Site Search method has a pre-determined list of keyphrases designed to be representative of the full gamut of discussion on the web. The Discovery Robot Manager ( 372 ) collects this information from the Discovery Targets DB ( 370 ) and executes a Site Search robot, which searches the input keyphrases to retrieve the first 20 pages of results. Because of the much larger number of searches, these robots are designed to heavily obfuscate and avoid patterned interaction with Search Engine servers. The URLs discovered by Site Search robots are delivered to the de-duplicator ( 388 ), and from there to the Collection Prioritization DB ( 390 ). Site Search robots can also alternately be sent input URLs that are blog sites instead of search engines. Within this context they will visit every hyperlink on the site, searching for new links to previously-unknown sites. This be delivered as new URL output similar to the other methods. The third method, called Host Crawl, uses different robots to visit the directory listing pages on major CGM hosting engines. These directory pages' URLs are stored in the Discovery Targets DB ( 370 ). The Discovery Robot Manager ( 372 ) launches a Host Crawl Robot ( 376 ) which visits a CGM Host directory page ( 382 ) and visits all of the hyperlinks on that page retrieving all of the URLs that are available. This information is sent to the de-duplicator ( 388 ) and on to the Collection Prioritization DB ( 390 )
[0079] Ingestion
[0080] FIG. 5 depicts one embodiment of a data ingestion system. This system receives input from the XML data outputs of robots launched and administered by the Collection Manager ( 400 ). These XML data sources are queued in an Ingestion Queue ( 405 ). This queuing process is a buffering function because all of the remaining steps are a stream processing method which requires a steady stream of content to work at maximum efficiency. Due to the dynamic nature of the volume of XML data input, the Ingestion queue holds a backlog of incoming data and outputs it at a steady rate, currently 500 docs/second. This flow of data is delivered first to a system which compares incoming CGM content information to all previously collected content, based on posted date, permalink URL, and post body to ensure that the data does not already exist in the system. This is the de-duplicator ( 410 ). Once this system has culled duplicate documents, it hands those documents to a UREF constructor ( 415 ) which creates a new uniqueID number to easily index and track unique content within the system in one embodiment of the invention. Next, content is delivered to a GMT time aligner, which converts all date and time stamps to be relative to Greenwich Mean Time ( 420 ). Next, this XML format information is transformed using an XSLT ( 425 ) or eXtensible Style Lanugage Transformation processor, which reformats the data for rapid delivery into the indexing system and relational DB systems ( 430 ). In one embodiment, TruCast performs several cleaning and refining steps upon incoming CGM content enclosed in the XML format. The system eliminates duplicate content using a fuzzy logic comparison between existing stored content and incoming new content based on post body, permalink, and date information. This comparison is tunable and weighted, where positive matches are clear indicators of duplication, but agreement is optionally advantageous across multiple values to confirm duplication. For example, if two posts came from exactly the same date and time to the second, it's unlikely, but possible, that they are truly different unique posts. If, however, the body text is 90% the same, and the URL is 90% the same, it's extremely unlikely that the two posts are unique. On body text, this comparison includes text clustering analysis, to use word counts as a computationally inexpensive way to further evaluate uniqueness. Content that is malformed or incomplete according to the data spec is removed and warnings sent to the responsible collection manager element. Once a document is determined to be unique a UREF (unique reference) value is created and appended to it so that there is a relevant single value to index this information within the system. All incoming post dates are aligned to GMT. In one embodiment, TruCast delivers all prepared content into an indexing system which formats the data in such a way that it can be rapidly searched based on relationships to other data, keyword presence, account relevance, and date. This structure includes storage of data within a distributed indexed data repository as well as several SQL databases. Each SQL database is optimized for a different consuming system: the UI, the visualization systems, the reporting and statistics systems, the collection priority database, and the target discovery database, as well as the individual account level data stores.
[0081] Analysis
[0082] In one embodiment, TruCast is designed to determine, with a high degree of confidence, the conceptual relevance of a given piece of CGM content to a “topic” or concept space. Topics can be of any breadth (“War” is just as sufficient a topic as “2002 Chevy Silverado Extended Cab Door Hinge Bolt Rust”). Topics are abstract identifiers of relevance information about a given piece of CGM content. Each topic can also be understood as a list of “keyphrases” or keywords with Boolean modifiers. Each topic can contain an unlimited number of keyphrases that work as the first tier of pattern matching to identify content that is relevant to an individual account. Each post discovered by the system, and, in one embodiment, could be relevant to one topic, many topics, many topics across many accounts, or no topics at all.
[0083] FIG. 6 depicts one embodiment of a system for manually appending topic relevance and topical sentiment to blog posts. This process begins by discovery of potentially relevant content by way of keyphrases. Keyphrases are grouped into topics. Topics and keyphrases are created by users ( 455 ) in the Topic Manager panel ( 460 ) within the UI. Once a new topic and keyphrase is created, this information is transmitted to the indexing system ( 465 ) which begins to examine all incoming data for matches against this keyphrase. The information is also handed to the relational database system ( 470 ) which is also the StoreDB component of the Historical Data Processor as illustrated in FIG. 38 . This system examines all data that has already been processed to see if it matches this new keyphrase. This separation accelerates both processes because of optimized structure in ( 465 ) for stream processing and optimized structure in ( 470 ) for narrow, deep searches against a significantly larger dataset. Information from both of these systems are passed in queue form to the Scoring Manager ( 475 ) which provides a UI for users to annotate topic relevance and topic sentiment information which is stored in the relational DB ( 485 ). In one embodiment, TruCast contains a user interface that allows users to create topics, create keyphrases that are used to search for potentially relevant posts for that topic, place potentially relevant content into a queue for review, review the text and context of individual content, mark that content as relevant to none, one, or many topics, (thereby capturing human judgment of relevance), and store that information in the relational database. This system is called the Scoring Manager.
[0084] This method, where a post is matched by keyphrase, scored by humans, and delivered to the outputs of TruCast, in one embodiment (visualizations, reports, and response), is a basic “manual” behavior of the system.
[0085] The behavior of this tiered system of relevance discovery and analysis changes over time to reflect the maturation of the more sophisticated elements of the system as their contextual requirements are much higher. A keyphrase match is absolute, in one embodiment; if a post contains an appropriate keyphrase, there is no question as to if a match exists. The Conceptual Categorization system is built to apply a series of exemplar-based prediction algorithms to determine the conceptual relevance of a given post independent of exact keyphrase match. This makes the system, in one embodiment, more robust and provides more human-relevant information. In an exemplary embodiment a blog post body includes the following text: “I really enjoy looking out my windows to see the vista out in front of my house. Buena! It is so great! I wish my computer was so nice, it is a little broken edgy eft sadly.” (EX. 1)
[0086] A topic for the Microsoft Corporation, looking for the words “windows vista computer” in order to find online discussion about their new operating system would find this post by keyphrase match, despite the fact that the user discusses using “edgy eft” which is a code name for Ubuntu 6.08, a competitor's operating system. A topic for Milgard Windows and Doors Corporation that is looking for discussion about windows in need of repair would find this same post looking for the keyphrase “broken house windows” despite the fact that clearly the writer is enjoying looking out of his unbroken windows. The Disney Corporation, looking for discussion about their film company “Buena Vista” would find this post, which has nothing to do with them at all. A biologist researcher looking for references to immature red newts would search for “Eft” only to be sadly disappointed in another result about Ubuntu's software. In all of these cases keyphrase matches have proven insufficient to successfully match relevant content to interested parties. Boolean modifiers help (vista NOT Buena) but consistently fall far short of expectations, and require non-intuitive and time consuming research and expertise.
[0087] Automated Conceptual Categorization
[0088] FIGS. 7-9 show the smooth transition between user scoring and automated scoring and depict the progression of the operation of one embodiment for an automated categorization and sentiment analysis system. This progression occurs from the early state, where the automated system performs poorly due to a lack of contextual examples, to a mature state where the automated system performs excellently as a result of robust contextual examples. The system, in one embodiment, reacts to this improvement by reducing the rate of post queue delivery to users and increasing the acceptance of analyzed posts from the automated system as confidence ratings and exemplar set sizes increase. This process accepts input from the ingestion system ( 350 ) into two separate queues. The first queue delivers content to the scoring manager ( 610 ) where it is scored by humans ( 615 ) and then delivered to the per-topic exemplar sets ( 620 ) based on topic relevance, the relational database ( 625 ) for storage and use in the response, visualization and report sections, and to an agreement analysis system ( 645 ). A second queue delivers content to the automated categorization system which accepts input from the per-topic exemplar sets, as well as topic performance and tuning information from the agreement analysis system ( 645 ). This system passes conceptually relevant content to the sentiment analysis systems which also has access to the exemplar and agreement analysis tuning data. The automated systems append a “confidence” score to their evaluations, which are used as a threshold to decide trust in the evaluation's accuracy. In the early behavior of the system, due to the lack of examples and agreement analysis tuning data, often this confidence score is very low. As more manual scoring is completed, and agreement analysis improves, the percentage of data flowing into the automated systems increases, and once performance is proven on the full data stream, the flow of data to the manual scoring application begins to decrease. Continual tracking of the agreement analysis system tracks for the varying level of inaccuracy that the automated systems can create as a result of changes within topical vernacular, user vocabulary, or new common phrases, inflections, or other changes in the typical word patterns present in incoming CGM content are reflected by the dynamic adjustment of the percentages of data flowing into these two systems. Over time, given sufficient, accurate scoring by humans, the automated systems should be capable of accurate analysis on 100% of incoming documents, which would reduce the role of required human interaction to only providing audit and contemporary vernacular updates by way of minimal scoring. In one embodiment, TruCast, contains a Conceptual Categorization system which has functionality to evaluate posts for relevance by way of statistical analysis on examples provided by humans using the scoring system. Because humans are reviewing the content, from a specific customer's perspective, that content is reliably scored in context. If the above example post (EX. 1) was scored by a human scorer for Microsoft, it would be found irrelevant to the Windows Vista operating system. By statistical analysis of hundreds of posts marked relevant or irrelevant to individual topics, the system can utilize not just keywords, but the entire body of the post to determine relevance. This statistics calculation leverages text clustering assisted by stop words exclusion, noun and pronoun weighting, punctuation observation, and stemming near-word evaluations. For non-text categorization analysis, TruCast, in one embodiment can leverage Optical Character Recognition (OCR) image to text conversion, Fast-Fourier Transform (FFT) and Granular Synthesis (GS) analysis based speech-to-text conversion, as well as Hierarchical Temporal Memory (HTM) processing. This comparison, and the resultant threshold filtered probability that a given post is relevant to a given topic allows TruCast, in one embodiment, to assign this meta-information. This method is vastly more accurate to human analysis than keyphrase matching. It also has the optionally advantageous feature of being continually tuned by ongoing scoring within the UI, which provides fresh exemplar data over time.
[0089] Automated Sentiment Analysis
[0090] When users score content for relevance in the scoring manager, they also may assert the sentiment of the content for each topic that it is relevant, from the perspective of their account. Users will mark, from their perspective (as informed by a set of scoring rules described by user administrators) the sentiment reflected about each topic. This information will be stored for later use in a relational database.
[0091] These human markup actions serve two purposes. First is to capture this data for direct use within a response system, and a series of data visualizations that leverage topic and sentiment information to elucidate non-obvious information about the content TruCast collects, in one embodiment. This is the “manual” path for data to flow thru the system, in one embodiment. The second use for these posts is that they serve as example data for an exemplar driven automated sentiment analysis system that mirrors the conceptual categorization system.
[0092] Similar to the process of categorization, the system, in one embodiment, leverages an exemplar set of documents to perform an automated algorithmic comparison in order to determine the sentiment, per topic, contained within an individual post. This requires a larger number of examples than categorization analysis, (˜100 per sentiment value per topic) due to the four different stored sentiment values, “good”, “bad”, “neutral” and “good/bad”. Due to the significant complexity of sentiment language within human language, additional processing is performed upon each document to improve the accuracy of the analysis. A lexicon of sentimental terms is stored within the system, and their presence has a weighted impact on the analysis. Negation terms and phrase structures also alter the values associated with sentimental terms. A stop words list eliminates connective terms, object nouns, and other non-sentimental terms within the text, reducing the noise the comparison has to filter thru. Sentence detection uses linguistic analysis to subdivide posts into smaller sections for individual analysis. A series of algorithms are compared for accuracy and performance on a per topic basis, to allow the performance of the analysis system to be tuned to each topic.
[0093] Automated Analysis Management
[0094] Both of these processes work upon the post-ingestion content, directing automatically analyzed documents into the remainder of the system workflow. This process reacts to the number of exemplar documents that are available. If incoming content is keyphrase-relevant to a specific topic, a determination is made if sufficient exemplar documents have been gathered by the system from users. If enough exemplary documents are not available, that post is delivered to the scoring queue which feeds content to the scoring manager interface. If some documents are present as exemplars, the system will attempt automated categorization and sentiment analysis, but still deliver posts to the scoring manager. This creates a pair of analysis results, one from the computer and one from the user. These are compared, and when a sufficient alignment (agreement frequency) is reached, the system starts delivering auto-analyzed content directly to the reporting and response systems, saving human effort.
[0095] This is a sliding ratio from 100% being delivered to the UI and 0% being auto-analyzed, to only 1-10% being delivered to the UI and 100% being auto-analyzed. Once the ratio of content being reviewed by human scorers reaches 10%, and accurate performance of the automated analysis is maintained, mature operation of the automated systems has been achieved. This is the most efficient operation of the system, in one embodiment.
[0096] The system utilizes an aging and auditing system to ensure that the oldest human scored posts are ejected from the exemplar set and replaced by new human scored posts over time. The system also performs internal cluster analysis and ejects significant outliers from the system. Both of these processes are tunable by administrative control panels. The result of this aging and auditing should be that as the vernacular, word usage, and issues discussed internal to a given topic change over time, exemplar documents continue to reflect that change and accurately map relevance.
[0097] Reporting
[0098] The system, in one embodiment, of databases which receive topic relevant, analyzed content is connected to a series of web-based visualizations to allow users of the UI to understand valuable information about the discussions captured by the system, in one embodiment. Visualizations are shown in FIGS. 27-38 .
[0099] Response
[0100] FIG. 10 is a depiction of one embodiment of a CGM response engine. In this embodiment the Response Manager UI ( 752 ) is populated with a written response by a user ( 758 ). This user is evaluated for authorization permissions against a stored value in the Account Database ( 754 ). If the user does not have appropriate authorization, their response will be delivered to an authorization queue ( 756 ) to be approved by an administrator. If a response is not approved it is deleted. If a responder has authorization, or their response is approved, it will be delivered to the Response Priority Processor ( 760 ) which determines if any delay or promotion is required for a given approved post. It also observes the original posted date of the content that is being responded to and prioritizes based on most recent posted dates. The Response Engine Manager ( 764 ) requests responses from the Response Priority Processor ( 760 ) to deliver to the registration and response robots. The Response engine manager checks the response performance DB ( 766 ) to see if a given URL has a response robot that has already been created or not. If it has not, the response and all associated information is sent to the Response Robot Constructor ( 772 ). This tool provides an interactive UI to allow semi-automated interaction with a target CGM site's registration and response systems to deliver the response to the site, and record the interaction. These interactions include loading pages, following hyperlinks, assigning input data to site form fields, navigating to web mail systems for authentication messages, completing CAPTCHA tests, interacting with IM and SMS systems, performing sequential interactions in correct order and submitting forms. The result of these actions should be a newly registered user (if required by the site) and a response written to the blog site. The interaction is recorded and stored in the Registration and Response Robot sets ( 770 , 774 ). If, when the Response Engine Manager is sent a response, it determines that a robot already exists, it will execute that robot without human interaction. This has the same effect, creating a new registration if required, and writing the response to the CGM site. Success or failure of robots and robot constructor actions are recorded in the Response Performance DB for evaluation and manual code re-work if required.
[0101] The response manager is a system to convert into a manageable, scalable business process the task of responding to CGM content by way of comments. All CGM systems that allow interactivity (>90%) have a web based system for allowing readers of content to respond by way of a comment, note, or other stored message. This often requires that users register themselves on the site, by providing a username, password, and other personal details. Sometimes this requires providing an e-mail address, to which an activation link is sent, or an instant messenger account which is sent a password. This isn't too difficult for casual users to maintain, especially if they only interact with a few sites. Professional users however often have to interact with thousands of different sites. The system, in one embodiment, aims to reduce this workload for responders by automating the registration and response process.
[0102] Response Workflow
[0103] In one embodiment, the TruCast UI system facilitates a workflow for many users to interact in a coordinated, managed way with CGM content. Once a post as been successfully analyzed by either a user in the scoring manager, or the automated analysis systems it becomes available within the response manager. This is a UI system for a user to write a comment in response to relevant posts. The UI two halves, one which shows information about the post being responded to (author, date, body text, and other comments from within the thread, as well as stats about the author and site responsible for the content.), and the second that contains the new response the user is writing. The system provides an interface called the response vault for managers to pre-write message components, fragments of text, names, stats, and pieces of argument that they'd like responders to focus on. These snippets can be copied into the response body during authoring. Once a user is done writing a response, the can click a “send” button which delivers the newly written response to the relational database.
[0104] Response Automation
[0105] FIGS. 11-13 show screen shots of a registration and response feature. Once the system, in one embodiment, receives a response record from the response manager, it determines which blog site contains the original message, and the link to the response page for that site and message. If the system, in one embodiment, has never written a response to that site before, the record is delivered to the response interactor UI or Response Robot Constructor, which is run by company employees. This UI allows an employee to visit the appropriate site, navigate to the appropriate fields, and assign the information from the record to fields on the site that will cause the site to record a response. This action is recorded, and converted into a script, which is stored as a new robot for later re-use. If TruCast has already written a response to a given site, this script will be used eliminating the need for repeated human interaction.
[0106] This system utilizes a similar engine and scripting methodology as the collection system. Registration and Response robots are scripted automations, which interpret the code of CGM content pages, web pages, pop3 or web based e-mail systems, and other data structures, and perform pre-determined, probabilistic, or rule driven interactions with those structures. By interpreting page code and scripted instructions, they can imitate the actions of human users of these structures, by executing on screen navigation functions, inserting data, gathering data, and reporting success or failure. An example registration robot would be given as a data input the registration information for an individual user of the system, in one embodiment, and given the URL to a site that the user wishes to register on. The robot would visit the site, navigate by markers pre-identified in the page code to the appropriate form locations to insert this information, confirm it's insertion, and report success, as well as any output information from the site. An example response robot would accept as input the registration information for a given user of the system, in one embodiment, the blog response they've written, and the URL to the site that the user wishes to respond to. The robot would load the site into memory, navigate the page by way of hyperlinks or pre-determined, probabilistic or rule driven information, examine the page source code to discover the appropriate form fields to insert this input data into, do so, and report success. Other embodiments of this solution could include purpose built scripts that perform the same assignment and scripted interaction with CGM sites to perform registration and response tasks. Smaller scale systems would have users perform the manual field entry and navigation tasks, but captures these interactions for conversation involvement identification and maintenance by the analysis systems.
[0107] Once the system, in one embodiment, receives a response record from the response manager, it determines which blog site contains the original message, and the link to the response page for that site and message. If the system, in one embodiment, has never written a response to that site before, the record is delivered to the response interactor UI, which is run by company employees. This UI allows an employee to visit the appropriate site, navigate to the appropriate fields, and assign the information from the record to fields on the site that will cause the site to record a response. This action is recorded, and converted into a script for later re-use. If TruCast has already written a response to a given site, this script will be used eliminating the need for repeated human interaction.
[0108] This system utilizes a similar engine and scripting methodology as the collection system. Other embodiments of this solution could include purpose built scripts that perform the same assignment and scripted interaction with CGM sites to perform registration and response tasks. Smaller scale systems would have users perform the manual field entry and navigation tasks, but captures these interactions for conversation involvement identification and maintenance by the analysis systems.
[0109] There are several sophisticated systems for preventing automated interaction with registration and response forms on CGM sites. Because TruCast is engine and script driven, and each transaction happens by way of a modular execution system, the system can tie the process to outside support modules to defeat these automation prevention systems. The response automation system has a complete pop3 e-mail interaction system which can generate e-mail addresses for use in registration, check those addresses for incoming mail, and navigate the mail content as easily as more typical web content. The response automation system uses advanced OCR processing along with human tuning to defeat CAPTCHA protections. The system has access to jabber protocol interactions to create automated IM accounts and interact by SMS with mobile phone systems. TruCast also stores a significant body of information, in contact card format, about responders so more complex registration questions can be correctly answered.
[0110] Conversation
[0111] The response system within TruCast delivers posts to blog sites, which are the target for the collection system. As the system, in one embodiment, collects content it matches incoming content to evaluate if that content belongs to a thread that the system has interacted with. When the system discovers posts that were written after a response that TruCast wrote, it is returned to the queue of posts assigned to the user who wrote the response, with a maximum priority. This way a conversation can be facilitated. The system also allows review of conversations by way of an Audit Panel, which gives a timeline of interaction for a conversation between a blogger and a TruCast user.
[0112] Transparency
[0113] Given the volatility of the CGM space, the value it represents, and the danger of negative publicity for any companies or other interested parties who choose to interact by way of responding by comment, it is optionally advantageous to maintain the appearance of correct attribution. The users are responsible for the content they generate. Because of the sophisticated analysis tools available for CGM site owners to evaluate the source of incoming comments, it's optionally advantageous that the system, in one embodiment, correctly portrays correct attribution. While using the TruCast system to automate response delivery to blog sites, correct attribution of content origination is retained.
[0114] Indicators of origination include: (1) E-mail address used in registration/response process; (2) Owner of e-mail address domain's as reported by the WHOIS information; (3) Receipt of e-mail sent to this address by the correct customer to the system, in one embodiment; (4) IP Address used in the response/registration process; (5) Reverse DNS lookup on the IP Address used in the response/registration process, and the resultant WHOIS information; and/or ( 6 ) Internal consistency of blog user registration information.
[0115] Any given customer or user will direct a domain name that's appropriate for blog post response, connect this domain (and its MX record) to web accessible server. This server should make available the e-mail addresses hosted on it via a pop3 connection. This resolves issues 1 and 2 by placing ownership of the domain from which the e-mails for registration are generated into the hands of the users.
[0116] A forwarding system between e-mail addresses created by a robot and the e-mail address listed in the User Manager exists. Forwarding messages from this TruCast controlled site to the customer's e-mail ensures that customers receive any messages from bloggers that reply by e-mail. This resolves issue 3.
[0117] The Response Automation tool receives port 80 from the IP address used for the e-mail server installation, and the server hosts the Response Automation Engine for use in executing the scripting that is created to perform automated response. This resolves issues 4 and 5 by aligning the IP source of the comments with the e-mail source of the comments.
[0118] The tool collects significantly more information about responders than is typically necessary. This includes obscure information like birth date, favorite car, mother's maiden name, favorite popsicle flavor, user picture, etc, to ensure that registrations are complete, feature rich, and transparent. The manual response app and robots accept this data in the response and registration steps. This resolves issue 6.
[0119] By way of this unified approach to transparency, attribution accuracy should always be retained.
[0120] If customers or other users desire misattribution of message source, IP and e-mail anonymization features can be enabled. This obfuscates the source of output messages by way of a rotating IP proxy environment which leverages P2P and onion topologies for maximum opacity.
[0121] Administration
[0122] It is valuable to keep blog-focused workers on message, saying appropriate things, making persuasive arguments, and being considerate participants in the community. In order to facilitate this, the system, in one embodiment, has a set of authorization features. Administrators have access to a per-user toggle which forces the posts that users write to be delivered to a review queue instead of the response automation system when they press the “send” button. This queue is accessible by administrators to allow review, editing, or rejection before messages are submitted.
[0123] Administrators can also create and manipulate sorting rules which prioritize content within user scoring and response queues based on topic, site, engine, author, and date information. This forces users to work on appropriate content, and allows administrators to segment scoring and responding tasks to SME's who have the most context for a given topic, site, engine or author.
[0124] Accounts
[0125] Users in the system, in one embodiment, are members of accounts, and afforded permissions within the system based on the role assigned to them by administrative users on a per account basis. Roles are pre-bound permission sets. Administrators can create, edit, and delete everything within the system, except accounts. Group administrators, who have access to multiple accounts, can create accounts, and can edit and delete accounts that they've created or been given access to. System administrators can add, edit, and delete all accounts, so this permission role is reserved for internal support use only. Users within the system, in one embodiment, are intended to perform the majority of the scoring and responding work, and as such have only access to the scoring manager, response manager, and their own user manager to review their own performance. Group users can do these tasks for multiple assigned accounts. Viewers within the system, in one embodiment, have read only access to all UI controls. Group Viewers can review multiple accounts. Accounts as a whole can be enabled or disabled, which blocks users from accessing the system if their account is disabled, and stops any account specific collection, analysis or processing tasks.
[0126] FIG. 15 shows an example screenshot of the user interface homepage 1300 . The homepage 1300 enables a user to navigate through the different functions of the UI. The toolbar is located at the bottom of the screen and features two menus (account menu and control panel) and a row of eight icons: Account Manager 1305 , User Manager 1310 , Topic Manager 1315 , Sorting 1320 , Scoring Manager 1325 , Response Manager 1330 , Dashboards 1335 , and Reporting 1340 . The account manager 1305 is used to create/set-up accounts and deactivate/reactivate accounts. The user manager 1310 is used to set-up/create users, establish group rights and permissions, and to review user activity. The topic manager 1315 is used to set-up/create topics and to set-up/create key phrases. Sorting, 1320 , is used to set-up/create scoring and responding rules for a topic, site, author, engine, and/or date and assign rules to a specific user. The scoring manager 1325 is used to read/score posts and create new topics while scoring a post. The response manager 1330 respond to posts in near real time and create/save personas and pre-determined responses. Dashboards 1335 is used to map and graph sentiment, impact, authority and data. Reporting, 1340 is used to display statistical charts. Finally a control panel 1345 is used to log out of TruCast and allows email to be sent directly to user support.
[0127] FIG. 16 shows an example screenshot of the account manager 1305 . The account manager is accessed by a user through button 1305 in FIG. 15 . The account manager 1305 creates and manages accounts in TruCast. Accounts serve as the logical groups of related users, topics, and other system elements. This creation action establishes a new GUID identified accountID that is used by the backend systems to identify data pertinent to this account. Account is often synonymous with customer for TruCast.
[0128] FIG. 17 shows an example screenshot of the user manager 1310 . The user manager 1310 allows administrators to set-up users, to assign specific rights/permissions to them and to evaluate their activity in TruCast. This is how a work team is created to address a specific target issue within the CGM space. Each new user is assigned a userID value to track their activities, and identify their actions at the database level, enforce permissions and limit access. All users who login to TruCast already have a userID. The response authorization required flag determines if a user's responses need to be approved by an administrator via the authorization system.
[0129] FIG. 18 shows an example screenshot of a topic manager 1315 . FIG. 19 shows an example screenshot of the topic manager 1315 with the Keyphrases tab activated. The Topic Manager 1315 is where administrators define topic titles, create topic descriptions, determine key phrases, and exclude specific phrases from the assigned topic. This will determine the content that is matched by the keyphrase tier of relevance analysis in TruCast. Topics are also analysis points, so they're used later to compare and contrast in the visualization systems. Each topic and keyphrase has a GUID value distinguishing it within the database systems.
[0130] FIG. 20 shows an example screenshot of a sorting manager 1320 . FIG. 21 shows an example screenshot of the sorting manager with the users tab activated. Sorting 1320 enables administrators to define scoring and responding guidelines. Administrators can create rules that either impacts all users or a specific user's scoring or responding queue will be sorted. These sorts impact the queue by matching, so all posts that match the rule are sorted to the top of the queue, which allows users to score items that are of general importance after completing scoring the posts that were specifically assigned to them by an administrator.
[0131] FIG. 22 shows an example screenshot of a scoring manager 1325 . The analysis system, having determined that a post matching either keyphrase or conceptual categorization, filtered by the sorting system, delivers posts in a sequential queue to the scoring system. Scoring is the central method for users to impact the function of the automated systems, providing examples and context for their operation and it's the shortest path for a post to make it from ingestion to visualizations and response. The post is placed in text box 2005 , the topics that the post relates to are in box 2010 , which a user will rate using the radio buttons presented. Finally the site information related to the post is placed in box 2015 .
[0132] FIG. 23 shows an example screenshot of creating a new topic 2110 in the scoring manager 1325 . Because pre-determined topics may not cover the scope or issues that exist in the discussion discovered by TruCast, TruCast allows scoring users to create topics, in the new topic text box 2110 , on the fly to capture the observation that a new loci of discussion exists. These topics are not populated with keyphrases at this step. Instead, administrators have the capability to merge and delete topics from the Topic manager to ensure that all the team members who may have simultaneously discovered this new topic can receive direction from the administrator as to what the final topic title will be, and instructions by way of descriptions and scoring rules about how to interpret it.
[0133] FIG. 24 shows an example screenshot of a response manager 1330 . The output from the analysis system and the scoring manager 1325 feed into the response manager 1330 based on applicable sorting rules as assigned by administrators. Writing the response, in block 2210 , and clicking “post” is all that's required, in one embodiment, to ensure that the message you typed makes it out as a comment on the target site. Your writing process is supported by significant contextual information, from the topic relevance and sentiment score information to stats about the original author and the site they posted on. Once you submit one response, the next item for your review is available immediately in the same panel, no need to navigate to other pages or sites to find the next place to communicate.
[0134] FIG. 25 shows an example screenshot of an administrative queue 2300 . The administrative queue tools allow administrators to exercise control over User response activities. These queues can be used for managerial oversight, legal review, tactical analysis, training, feedback and performance auditing. They create the framework for administrative authority over the response process.
[0135] FIG. 26 is an example screenshot of a dashboard manager 1335 . The Dashboard displays data in dynamic graphical charts and graphs. It maps and reports information based on impact, sentiment, authority and data. This allows users to easily identify critical issues, compare topics of discussion for volume, breadth, depth, tone and interconnectedness of CGM discussions, as well as other useful insights about the CGM space.
[0136] FIG. 27 is an example screenshot of an Impact Dashboard 2500 and it refers to a set of three line graphs which show daily totals over time that depicts the breadth, depth, and participation of the discussions contained within one or many topics. This information is combined with a polar chart that shows the combined values of the three graphs for one period.
[0137] FIG. 28 is an example screenshot of a Sentiment Dashboard: refers to a snapshot view of a single period, showing the relative post volume versus the average sentiment of your selected topics. FIG. 29 is an example screenshot of a Sentiment History Dashboard. This display is connected to a history view which displays this information over time.
[0138] FIG. 30 is an example screenshot of an Authority Map Dashboard: refers to a node and edge style interactive display which shows the interconnectedness and relative authority of individual authors within a given topic. It shows topic as the center node, sites that contain relevant content as first edge nodes, and authors as second edge nodes. Edges between authors connote comments, links, quotes, and trackbacks as methods of identifying connection and communication. A list view on the right side of the screen allows you to quickly find specific authors or sites within the display. Adjustable level of depth controls allow users to establish constraints (show only authors with more than 2 links, show only positive authors, etc.) that effect the visibility of nodes in the display.
[0139] FIG. 31 is an example screenshot of a Data Dashboard: refers to a display that shows a tabular result set of posts that matched the topics selected. This table shows one post per row with columns for date, author name, permalink, site name, sentiment, and topic. This view can show only information based on keyphrase-relevance, or full analyzed relevance, or show those two together. In several other dashboards there are links to more information about a given topic or author. Those links point to this display.
[0140] FIG. 32 is an example screenshot of an Ecosystem Map: refers to an Ecosystem map is a node and edge style display of all of the sites that make up the discussion ecosystem for a given topic or topics. It shows a node for each site that contains posts or comments relevant to the topics selected and date ranges selected in the dashboard launcher panel. Between nodes, there should be an edge for each link that connects nodes together.
[0141] FIGS. 31-32 show example screenshots of Nodes and are size scaled depending on how many posts/relevant posts they have, and colored by average sentiment. Edges are thicker depending on how many links exist between two nodes, and have size scaled arrows showing the predominant direction or ratio of links. Nodes, if clicked on should show the site name, # of posts total, # of relevant posts, and sentiment %. The name is a hyperlink to the site. By selecting an individual topic a more detailed display with the sites and authors most important to a given topic displayed. Double click on the node would lead to the data dashboard with a list of all the titles and permalinks to the relevant posts on that site. Edges, if clicked on, show the # of links represented, % directionality.
[0142] FIG. 35 is an example screenshot of a Sentiment Summary: refers to a single topic display that shows the number of authors per sentimental category on a given topic or sum of topics.
[0143] FIG. 36 is an example screenshot of Top Lists: This provides users with a set of ranked lists of sites, authors, and posts that are the most relevant, most popular, most negative, most positive, most authoritative, most influential, most linked to, most commented on, or most responded to depending on user selection.
[0144] FIG. 37 is an example screenshot of a Reporting: The reporting system provides a series of charts based on selection criteria revolving around CGM content. Daily or total values of posts by keyphrase match or post-analysis match, per topic or topics, site, author, by date range. Performance metrics on scorers and responders are also available, per site, topic, or date range.
[0145] FIG. 38 is an example screenshot of an Aggregate Performance Dashboard: This dashboard supplies a cluster of configurable widgets for tracking the relationships between several KPI's associated with the data available within TruCast, in one embodiment.
[0146] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow. | TruCast is a method for management, by way of gathering, storing, analyzing, tracking, sorting, determining the relevance of, visualizing, and responding to all available consumer generated media. Some examples of consumer generated media include web logs or “blogs”, mobile phone blogs or “mo-blogs”, forums, electronic discussion messages, Usenet, message boards, BBS emulating services, product review and discussion web sites, online retail sites that support customer comments, social networks, media repositories, and digital libraries. Any web hosted system for the persistent public storage of human commentary is a potential target for this method. The system is comprised of a coordinated software and hardware system designed to perform management, collection, storage, analysis, workflow, visualization, and response tasks upon this media. This system permits a unified interface to manage, target, and accelerate interactions within this space, facilitating public relations, marketing, advertising, consumer outreach, political debate, and other modes of directed discourse. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is continuation-in-part of application Ser. No. 11/289,920, filed on Nov. 30, 2005, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to transparent protective coatings for polymeric substrates, such as windows and shields for view screens.
[0004] 2. Background
[0005] Polymers have a wide range of applications as transparent components. For example, many eyeglass lenses are constructed of polycarbonate, which is preferred to glass because of its lighter weight and greater ability to refract light. Aircraft passenger windows are typically made of stretched acrylic due to its light weight, flexibility and formability. Many electronic handheld devices, such as cellular phones, portable music players and personal data assistants, include view screens that are protected behind transparent shields. These shields can be made of polycarbonate, acrylic, resin-based plastics, etc.
[0006] Unfortunately, many transparent polymers do not have adequate resistance to wear and erosion from, for example, particulate matter (e.g. sand), water, chemicals and contact with other solid objects. These polymers would quickly develop scratches and crazing if subjected to the conditions to which eyeglasses, windows and handheld devices are typically subjected. For example, FIG. 1 illustrates an example of a substrate 10 that has suffered extensive scratches and crazing 12 . Therefore, to increase the wear resistance of these polymers they are typically coated with harder transparent substances.
[0007] Presently, acrylic and other types of aircraft windows are protected by sol-gel based polysiloxane coatings. The sol-gel coatings are homogeneous mixtures of a solvent, an organosilane, alkoxide and a catalyst that are processed to form a suitable coating. The sol-gel coatings provide high transmittance, but limited durability against wear and UV induced degradation. Moreover, during flight, aircraft windows are subjected to differential pressures caused by the difference in pressure between the inside and the outside of the aircraft. The combination of cabin differential pressure and aerodynamic stresses during flight causes the windows to flex, and therefore can cause most sol-gel coatings to crack, subsequently allowing chemicals to attack the acrylic substrate and in some cases allowing the coating to delaminate from the acrylic substrate.
SUMMARY OF THE INVENTION
[0008] The preferred embodiments of the present durable transparent coatings for polymeric substrates have several features, no single one of which is solely responsible for their desirable attributes. Without limiting the scope of these coatings as expressed by the claims that follow, their more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description of the Preferred Embodiments”, one will understand how the features of the preferred embodiments provide advantages, which include increased durability while preserving the ability of the substrate to flex.
[0009] One aspect of the present coatings includes the realization that there is a need for transparent, hard coatings that improve the durability and extend the lifetime of polymeric substrates. Of even greater advantage would be coatings that were resilient against chemicals and showed strong weatherability characteristics.
[0010] One embodiment of the present coatings comprises a duplex coating for a polymeric substrate. The coating is configured to enhance the durability of the substrate. The coating comprises a first, relatively soft, polysiloxane-based coating covering at least a portion of a first surface of the substrate, and a second, relatively hard, silicon-based coating covering at least a portion of the first coating. The first coating has a thickness of between about 0.1 and 10 microns, a hardness of between about 100 MPa and 500 MPa, and a modulus of between about 1 GPa and 9 GPa. The second coating has a thickness of between about 0.1 and 10 microns, a hardness of between about 100 MPa and 4 GPa, and a modulus of between about 8 GPa and 20 GPa.
[0011] Another embodiment of the present coatings comprises a method of forming a duplex coating on a substrate. The coating is configured to enhance the durability of the substrate. The method comprises depositing a first, relatively soft, polysiloxane-based coating on at least a portion of a first surface of the substrate, and depositing a second, relatively hard, silicon-based coating on at least a portion of the first coating. The first coating has a thickness of between about 0.1 and 10 microns, a hardness of between about 100 MPa and 500 MPa, and a modulus of between about 1 GPa and 9 GPa. The second coating has a thickness of between about 0.1 and 10 microns, a hardness of between about 100 MPa and 4 GPa, and a modulus of between about 8 GPa and 20 GPa.
[0012] The present duplex coatings advantageously improve weatherability, resistance to chemical exposure, wear resistance and resistance to flexing-induced crazing of substrates. In addition, the optical properties (light transmittance in the visible region of the solar spectrum, clarity and haze) of substrates with the duplex coatings are about the same as those of a substrate having a single polysiloxane coating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The preferred embodiments of the present durable transparent coatings for polymeric substrates will now be discussed in detail with an emphasis on highlighting the advantageous features. These embodiments depict the novel and non-obvious coatings shown in the accompanying drawings, which are for illustrative purposes only. These drawings include the following figures, in which like numerals indicate like parts:
[0014] FIG. 1 is a front elevation view of a substrate exhibiting extensive scratches and crazing;
[0015] FIG. 2 is a schematic cross-sectional view of a substrate with a duplex coating in accordance with one embodiment of the present coatings;
[0016] FIG. 3 is a graph illustrating Taber wear test results for stretched acrylic with polysiloxane and one embodiment of the present duplex coatings;
[0017] FIG. 4 is a schematic cross-sectional view of a three point flex test on a coated substrate;
[0018] FIG. 5 is a simplified schematic of a cyclic load/temperature profile used to test one embodiment of the present duplex coatings;
[0019] FIG. 6 is a graph showing changes in dry adhesion index of a polysiloxane coated stretched acrylic and one embodiment of the present duplex coated stretched acrylics as a result of exposure to various chemicals for 24 hours;
[0020] FIG. 7 is a graph showing changes in wet adhesion index of a polysiloxane coated stretched acrylic and one embodiment of the present duplex coated stretched acrylics as a result of exposure to various chemicals for 24 hours; and
[0021] FIG. 8 is a graph showing Taber wear test results of a polysiloxane coated stretched acrylic and one embodiment of the present duplex coated stretched acrylics after chemical exposure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIG. 2 illustrates schematically one embodiment of the present duplex coating for substrates. The substrate 14 may be any polymer, such as polycarbonate, acrylic, stretched acrylic or a resin-based structural plastic. The substrate 14 may have any configuration, such as flat or concave/convex, and may be adapted for use in virtually any application. For example, the substrate 14 may be a thin flat sheet adapted to be used as a protective shield over a view screen on a handheld electronic device, such as a cell phone or a personal data assistant. Alternatively, the substrate 14 may be a relatively thick flat sheet adapted to be used as a window in a passenger aircraft. Those of ordinary skill in the art will appreciate that the range of applications for the present duplex-coated substrates is endless. Additional examples of substrates that could include the present duplex-coatings include, without limitation, monitor screens (such as for computers and televisions) and protective shields for such screens, windows, windshields and sun/moonroofs for all types of land- and water-based vehicles, including cars, trucks, railcars and boats, protective shields over light sources, such as vehicle headlights/taillights and flashlights, protective shields over digital displays on electronic devices, such as alarm clocks, microwaves, ovens, digital cameras, etc.
[0023] A first surface 16 of the substrate 14 includes a first coating 18 , or “soft” coating 18 , and a second coating 20 , or “hard” coating 20 , overlying the first coating 18 . In one embodiment the soft coating 18 may be an adherent polysiloxane-based layer, and the hard coating 20 may be a silicon-based layer. Silicon-based materials are advantageously harder and more durable than polysiloxane-based materials. Unfortunately, however, silicon-based materials typically do not bond well to polymeric substrates. Thus, one advantage of the soft coating 18 is that it provides a bonding layer for the hard coating 20 . The soft coating 18 is applied to the substrate 14 prior to the hard coating 20 , and the hard coating 20 bonds chemically to the soft coating 18 layer and provides a hard outer surface.
[0024] The soft coating 18 need not be very thick to provide sufficient adhesion for the hard coating 20 . For example, in one embodiment, the soft coating 18 may be between about 100 and 200 Angstroms thick. In accordance with one advantage of the present coatings, however, the soft coating 18 acts not only as an adhesion enhancing layer, but also as a load bearing and flexibility enhancing layer. To enhance the flexibility and load bearing characteristics of the soft coating 18 , its hardness and modulus may be tuned. In one embodiment the soft coating 18 may have a hardness between about 100 MPa and 500 MPa, and a modulus between about 1 GPa and 9 GPa. An embodiment of the soft coating 18 having a hardness of about 300 MPa and a modulus of about 5 GPa has demonstrated advantageous properties of flexibility and load bearing capacity.
[0025] To further enhance the flexibility and load bearing characteristics of the soft coating 18 it may be made thicker. In certain embodiments the soft coating 18 may be between about 0.1 and 10 microns thick. The thickness of the soft coating 18 will be influenced by the anticipated application for the substrate 14 . For example, in applications where the substrate 14 needs to exhibit a greater amount of flexibility, the soft coating 18 may be relatively more thick, such as between about 4 and 5 microns. In other applications where the substrate 14 needs to exhibit a lesser amount flexibility, the soft coating 18 may be relatively more thin, such as between about 2 and 4 microns.
[0026] In one embodiment the hard coating 20 may be a silicon-based layer, such as for example a SiO x C y -based layer, with x ranging from 1.0 to 1.2, and y ranging from 1.0 to 0.8. Alternatively, the hard coating 20 may be a DIAMONDSHIELD® layer available from Morgan Advanced Ceramics of Allentown, Pa. or a transparent DYLAN™ coating available from Bekaert Advanced Coating Technologies of Amherst, N.Y. In one embodiment, the hard coating 20 is deposited onto the substrate 14 using plasma techniques, such as ion beam-assisted plasma vapor deposition or plasma-enhanced chemical vapor deposition. For example, several materials deposited using plasma techniques are disclosed in “Comparison of silicon dioxide layers grown from three polymethylsiloxane precursors in a high-density oxygen plasma” by Y. Qi, et al., Journal of Vacuum Science & Technology , A 21(4), July/August 2003, the entire contents of which are incorporated herein by reference.
[0027] The silicon-based coating is a relatively hard coating 20 that provides better wear resistance, chemical inertness and other durability properties as compared to other coatings generated by wet chemical methods such as sol-gel coatings. Further, the ion bombardment effects that occur during plasma deposition of silicon-based transparent coatings improve the hardness and durability of the coatings. The ion bombardment enhances the surface mobility of the depositing species and improves the optical quality (haze and clarity) of the coating. To enhance the durability of the hard coating 20 , its hardness and modulus may be tuned. In one embodiment the hard coating 20 may have a hardness between about 100 MPa and 4 GPa, and a modulus between about 8 GPa and 20 GPa. An embodiment of the hard coating 20 having a hardness of about 2 GPa and a modulus of about 14 GPa has demonstrated advantageous durability.
[0028] To further enhance the durability of the hard coating 20 its thickness may be tuned. In certain embodiments the hard coating 20 may be between about 0.1 and 10 microns thick. The thickness of the hard coating 20 will be influenced by the anticipated application for the substrate 14 . For example, in applications where the substrate 14 needs to exhibit a greater amount of flexibility, the hard coating 20 may be relatively more thin, such as between about 4 and 5 microns. In other applications where the substrate 14 needs to exhibit a lesser amount flexibility, the soft coating 18 may be relatively more thick, such as between about 5 and 8 microns.
[0029] The tuned hardnesses, moduli and thicknesses of the present duplex coatings advantageously enhance the durability of the substrates to which they are applied. Further, for flexible substrates the present duplex coatings enhance durability while also preserving the flexibility of the substrates. This flexibility preservation is of particular advantage when compared to prior art silicon-dioxide coatings, which have high hardness and high modulus. For example, for certain applications requiring a flexible substrate a duplex coating according to the present embodiments may be applied as follows. The soft coating 18 may have a relatively low hardness and modulus and relatively large thickness. The hard coating 20 may have a relatively low hardness, moderate modulus and be relatively thin. Such a duplex coating preserves the flexibility of the substrate 14 as compared to a silicon-dioxide coating because the soft coating 18 is able to bear some of the load as the substrate 14 flexes, and the hard coating 20 does not severely restrict the flexing of the substrate 14 and the soft coating 18 . The hardness of the duplex coating, however, reduces flexing-induced crazing that is typical of substrates coated with only polysiloxane.
[0030] Referring again to FIG. 2 , in one example embodiment the substrate 14 is first treated and coated with the soft coating 18 . The soft coating 18 may be a 4 to 5 micron thick polysiloxane-based, adherent, transparent coating. Next, the silicon-based transparent hard coating 20 is deposited on the soft coating 18 using an ion assisted plasma process. The hard coating 20 may be a 4 to 5 micron thick layer of DIAMONDSHIELD®. The deposition process may include at least one silicon-containing precursor, such as hexamethydisiloxane, and oxygen. The plasma deposition conditions, such as gas flow, deposition pressure, plasma power and the like, may be adjusted to produce hard, transparent coatings in accordance with well known plasma deposition principles.
[0031] In one embodiment the substrate 14 and/or the soft coating 18 may be chemically cleaned to remove contaminants, such as hydrocarbons, prior to loading the substrate 14 into a vacuum chamber for the application of the hard coating 20 . The cleaning process may include, for example, ultrasonic cleaning in solvents and/or aqueous detergents. Once the desired vacuum conditions are obtained, the substrate 14 may be sputter cleaned using inert ions and/or oxygen ions. After the cleaning step is complete, the hard coat may then be applied.
[0000] Coating Performance Evaluation:
[0032] A series of comparisons have been made to validate the improved performance of the present duplex coating versus a polysiloxane coating on acrylic substrates. The results of these comparisons are outlined below. Nothing in these comparisons should be interpreted as limiting the scope of the present embodiments.
[0033] To perform the comparisons, a first group (Group I) of stretched acrylic substrates was coated with a polysiloxane coating to a thickness of about 4 microns. A second group (Group II) of stretched acrylic substrates was first coated with a polysiloxane coating to a thickness of about 4 microns, followed by a plasma-based hard coating to a thickness of about 5 microns.
[0034] Wear Test:
[0035] The coated substrates (Group I & Group II) were tested for wear in accordance with the procedure described in ASTM D-1044-99, “Standard Test Method for Resistance of Transparent Plastics to Surface Abrasion”. This test includes two CS-10F wheels with a load of 500 gm applied to each. The wheels abrade the coated acrylic substrate surfaces as they rotate. The increase in haze was used as the criteria for measuring the severity of abrasion. The tests were run until the haze increased by 5% as a result of the abrasion. The results of tests are shown in FIG. 3 , which illustrates that the present duplex coatings exhibit improved wear resistance by more than an order of magnitude when compared to the polysiloxane coating.
[0000] Flex Test:
[0036] A modified ASTM D-790 test protocol was used to conduct the flex tests of the coated components. Samples 22 of dimensions 1″×12″×0.5″ with coatings 24 (Group I & II) were subjected to a three point bend test as shown in FIG. 4 . The surface 26 of the sample 22 having the coating 24 is facing down in this figure. A thin film of 75 wt % sulfuric acid in water was applied to the coating using a fiberglass filter and a TEFLON® tape. The test article was subjected to a cyclic load/temperature profile as shown in FIG. 5 . An ultimate load of 3600 psi was used in these tests. The tests were continued until the coating cracked or the surface exhibited crazing (whichever occurred first). The results show that while the polysiloxane coated substrates (Group I) failed in 50 cycles, the present duplex coated substrates (Group II) showed no cracking or crazing even after 500 cycles.
[0000] Chemical Exposure Test:
[0037] Stretched acrylic substrates with the present duplex coating were exposed to chemicals that are normally used in the performance of aircraft maintenance. The samples were exposed to each chemical for a period of 24 hours (exception: exposure to MEK was for 4 hours) and then tested for adhesion (modified ASTM D 3330-BSS 7225) and % haze change due to wear when tested per ASTM D-1044-99. The results are shown in FIGS. 6, 7 and 8 for the polysiloxane coated substrates (Group I) and the duplex coated substrates (Group II). The samples with duplex coatings exhibited no degradation in adhesion (as indicated by adhesion index) or wear induced haze change as a result of chemical exposure.
[0000] UV/Humidity Exposure:
[0038] The coated (Group I & Group II) substrates were exposed to ultraviolet light (UV-A lamp with peak wavelength at 340 nm) and humidity for a total exposure of 300 KJ/m 2 in accordance with SAE J1960. The exposure consisted of 40 minutes of light, 20 minutes of light with front spray, 60 minutes of light and 60 minutes of dark with front and back spray. Another set of samples from Groups I & II were first exposed to various chemicals (per the chemical test above) and then subjected to the UV/Humidity test protocol. In both of these tests, the samples with the duplex coating showed no degradation as a result of UV/humidity exposure and performed better than those with single polysiloxane coating alone.
[0039] The above description presents the best mode contemplated for carrying out the present durable transparent coatings for polymeric substrates, and of the manner and process of making and using them, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which they pertain to make and use these coatings. These coatings are, however, susceptible to modifications and alternate constructions from those discussed above that are fully equivalent. Consequently, these coatings are not limited to the particular embodiments disclosed. On the contrary, these coatings cover all modifications and alternate constructions coming within the spirit and scope of the coatings as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the coatings. | Duplex coating schemes and associated methods of formation, including a siloxane-based soft coating and a plasma-based SiO x C y hard coating used in combination to improve the durability of polymeric substrates. | 8 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/598,950 filed Feb. 15, 2012. This prior application is hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
[0002] (Not Applicable)
REFERENCE TO AN APPENDIX
[0003] (Not Applicable)
BACKGROUND OF THE INVENTION
[0004] The invention relates generally to commercial and residential heating ventilation and air conditioning (HVAC) filtration, and more specifically to a collapsible filter that is collapsed to reduce shipping volume and is readily constructed by the end user.
[0005] Traditional pleated filters for commercial and residential HVAC systems include one or more frame members and a pleated filtration media glued to the frame members. As is known in the field, the filtration media is pleated to provide greater surface area on which to collect particulate. The greater surface area takes longer to clog the pores of the media with particulate, thereby prolonging the life of the filter media. Furthermore, pleated media tends to be stronger than planar media in resisting deformation due to the force of air passing through the media. However, pleated filters occupy a large volume of empty space per filter due to the shape of the pleated media. While such filters have low weight, they tend to be expensive to transport when considering them on a per unit volume basis due to the large amount of empty space per unit volume.
[0006] It is known to construct filters of materials that are collapsed by the manufacturer and assembled by end users. Such filters have significantly reduced shipping volumes, but require the end user to expand and construct the finished filter so that it can be used in a conventional manner. Conventional collapsible filters require the filter components to depart significantly from traditional non-collapsible filter components at a significant cost disadvantage. U.S. Pat. No. 3,938,973 discloses such a prior art collapsible filter, and includes a pinch frame furnace filter that requires a combination of framing materials including heavier paperboard, expensive plastic components and/or adhesive for the end user to assemble. There is also a higher tooling cost with the plastic components, because such components lead to less flexibility on filter sizes available.
[0007] The need exists for an improved collapsible filter that permits an end user to expand and construct the finished product rapidly, with minimal skill requirements and without the prior art's cost disadvantages.
BRIEF SUMMARY OF THE INVENTION
[0008] The invention contemplates a collapsible air filter with a pleated air filter media assembly, a method of collapsing the same, and the collapsed structure. The filter media has generally rectangular panels interconnected together in a pleated configuration with each panel connecting to at least one adjacent panel at longitudinal panel edges. A filter frame member is preferably made from a generally planar blank and has a central area with at least one opening formed therein. The central opening enables airflow through the filter so the air can pass through the media. The blank has laterally opposite side walls and longitudinally opposite end walls that are foldable to positions substantially perpendicular to the central area.
[0009] The filter frame member blank preferably has a plurality of substantially parallel score lines extending laterally across the filter frame member to define hinge points for the filter frame member to fold along. The filter frame member is preferably folded, along with the pleated air filter media assembly, to a substantially collapsed condition in which a substantially U-shaped channel is formed in the filter frame member and a majority of the panels of the pleated air filter media assembly are retained in the U-shaped channel. It should be understood that the U-shaped channel can be a different shape, but that a U-shaped channel has advantages.
[0010] At least two panels at opposite ends of the pleated air filter media assembly are attached to the end walls of the filter frame member so that, upon expansion of the collapsed filter frame member, the two filter media assembly panels remain attached to the end walls of the filter frame member during simultaneous elongation of the filter frame member and the pleated air filter media assembly.
[0011] In a preferred embodiment, a second filter frame member is configured to mount to the filter frame member. The second filter frame member is made from a generally planar blank having a central area with at least one opening formed therein, thereby enabling airflow therethrough. The second filter frame member has laterally opposite side walls and longitudinally opposite end walls foldable to positions substantially perpendicular to the central area, and is foldable to a substantially collapsed condition.
[0012] In an alternative embodiment, the air filter has frame panels extending from the end walls and the side walls of the filter frame member. The frame panels are configured to fold over lateral and longitudinal edges of the pleated air filter media assembly to positions substantially parallel to the central area when the air filter is expanded. These frame panels substitute for the second filter frame member to retain the pleated filter media assembly in the filter frame.
[0013] The entire filter collapses to a small portion of its original dimensions for smaller shipping volume. Any suitable paperboard frame material, which could be replaced or supplemented by thin stock plastic or other folding, rigid material, will work for the frame member or members. In the embodiment with two filter frame members, one frame member frictionally engages the other to enclose and finish the filter, and tabs extending from one frame member are inserted into slots formed in the other frame member. No plastic components are required to make a filter of suitable structural integrity. Adhesive can be used to attach the frame members to one another. The assembly is simplified and all parts are disposable.
[0014] In the preferred embodiment, the pleated media assembly is attached to a filter frame member and the frame member is folded along with, and around, the pleated media. The pleated media assembly can be adhered to the frame member or attached with tape, hooks and loops fasteners, glue or any other fastener. A separate second frame member is folded but does not have pleat media attached, and is packaged with the frame member and pleated media assembly combination. As an alternative, the second frame member can be pre-attached to the first frame member. In another alternative, one or more of the frame members do not cover the entire side walls of the pleated media assembly but only a portion of one or more sides.
[0015] The frame member of the preferred embodiment is preferably paperboard that is glued at the corners and scored along lines extending across its width so the frame member folds up with the pleated media assembly mounted in it. The frame members could be made of plastic or any other suitable material. When folded up, a preferably substantially U-shaped region of the frame contains most of the panels of the pleat pack, and the other regions of the frame are folded as shown and described in detail herein to maintain small size and very little air space.
[0016] The collapsible filter preferably does not use glue or plastic clips in the assembly, but still results in a structurally strong finished filter product. In addition, all of the components become part of the filter and are easily disposed of. The preferred design in the collapsed form occupies approximately 15% of the volume of the expanded (ready-to-use) filter. This greatly reduces the cost of shipping. As an example, a finished 16×25×4 inch filter collapses to fit into a space of 16×6×2.5 inches. Of course, other finished and collapsed sizes are contemplated and possible.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] FIG. 1 is a view in perspective illustrating a preferred embodiment of the present invention, including the collapsed frame member with pleated media assembly and collapsed frame member.
[0018] FIG. 2 is an end view illustrating the preferred embodiment of FIG. 1 .
[0019] FIG. 3 is a view in perspective illustrating the collapsed frame member with pleated media assembly.
[0020] FIG. 4 is a schematic top view illustrating the frame member in a planar, pre-constructed state.
[0021] FIG. 5 is a schematic view in perspective illustrating the frame member in a constructed but pre-collapsed state.
[0022] FIG. 6 is a schematic end view illustrating the collapsed configuration of the frame member.
[0023] FIG. 7 is a view in perspective illustrating the collapsed frame member with pleated media assembly, and arrows indicating the direction of expansion.
[0024] FIG. 8 is a view in perspective illustrating the mostly expanded frame member with pleated media assembly.
[0025] FIG. 9 is a view in perspective illustrating the mostly expanded frame member.
[0026] FIG. 10 is a view in perspective illustrating the expanded frame member.
[0027] FIG. 11 is a view in perspective illustrating the expanded frame member with pleated media assembly.
[0028] FIG. 12 is a view in perspective illustrating the expanded frame member in position on the expanded frame member with pleated media assembly.
[0029] FIG. 13 is a view in perspective illustrating an alternative embodiment in which the frame member and pleated media assembly are expanded, and small flaps are upraised.
[0030] FIG. 14 is a view in perspective illustrating the embodiment of FIG. 13 with the flaps mounted in their final position.
[0031] FIG. 15 is a view in perspective illustrating the preferred embodiment in a finished state.
[0032] FIG. 16 is an exploded view illustrating the preferred embodiment.
[0033] FIG. 17 is a view in perspective illustrating an alternative embodiment of the present invention.
[0034] FIG. 18 is an end view illustrating the embodiment of FIG. 17 .
[0035] FIG. 19 is a view in perspective illustrating an alternative embodiment of the present invention.
[0036] FIG. 20 is a view in perspective illustrating the embodiment of FIG. 19 .
[0037] FIG. 21 an end view illustrating a magnified view of the embodiment of FIG. 19 .
[0038] In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word “connected” or terms similar thereto are often used. They are not limited to direct connection, but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Provisional patent application Ser. No. 61/598,950 is incorporated by reference into this application.
[0040] The preferred embodiment of the filter 10 is shown in a finished, assembled state in FIG. 15 . The filter 10 of FIG. 15 is illustrated in an exploded view in FIG. 16 , showing the frame member 20 , the pleated media assembly 30 and the frame member 40 . The filter 10 is shown in a collapsed state or condition in FIGS. 1 , 2 , 3 and 7 , and the components thereof will now be described with reference to the illustrations.
[0041] The frame member 20 is preferably formed from a single piece of planar paperboard, preferably in the shape shown in FIG. 4 , but any suitable material will be acceptable. After forming, the frame member 20 is folded to form laterally opposite sidewalls 26 and 28 and longitudinally opposite end walls 22 and 24 , all of which are generally perpendicular to a central area 27 (see FIG. 5 ). The frame member 20 is also folded in a novel way as described in detail below. Cutouts 25 are formed through the preferably paperboard of the central area 27 of the frame member 20 in a conventional manner, and thus provide openings through which air can flow when the completed filter 10 is in use.
[0042] In order to fold the frame member 20 to a desired, collapsed configuration, a series of folds are formed in the frame member, preferably by first scoring the frame member 20 along lines extending laterally across the frame member 20 , such as the substantially parallel score lines 21 and 23 , among others shown in FIG. 4 . The score lines 21 and 23 , along with all other score lines formed in the frame member 20 , are conventional score lines. The scores can be cut scores, which are grooves formed by slicing into the material through a fraction of its thickness, such as about one-half. Alternatively, the scores can be perforations or they can be pressure scores that compress the material but do not cut into it. These score lines define hinge points that the frame member 20 folds along, and any particular filter can use one or more of these types of conventional scores depending upon the location and features desired.
[0043] The pleated media assembly 30 is a filtration media, preferably a synthetic non-woven filtration media having a thickness preferably less than one-eighth inch, a Frazier air permeability greater than about 100 cubic feet per minute (CFM) and a basis weight of from 30 to 120 grams per square meter. Of course, a person having ordinary skill in the field will understand that any suitable filtration media can be substituted for the preferred media with attendant benefits and disadvantages. The pleated media preferably has a conventional reinforcement layer to retain the pleated shape after pleating, and also to provide support to prevent the filtration media from “blowing out” of the filter frame during use. The reinforcement can be a conventional pleating reinforcement, such as slit and expanded metal or plastic, but it could also be netting, “chicken wire” or any conventional support layer. Alternatively, self-supporting pleatable material can be used. The pleated media assembly has end panels 32 and 34 (see FIG. 16 ) that are preferably formed of the longitudinal end panels of the pleated media, but could alternatively be constructed of the longitudinal end panels mounted to paperboard or other rigid material panels.
[0044] The frame member 20 and the pleated media assembly 30 are mounted to one another, preferably prior to collapse of the combination as shown in FIG. 1 . In the preferred embodiment, the end panels 32 and 34 of the pleated media assembly 30 are mounted, preferably by adhering, to the end walls 22 and 24 , respectively, of the frame member 20 . In this manner the pleated media assembly 30 is fixed to the frame member 20 at each of their longitudinal ends, thereby maintaining the ends of each attached to one another to move simultaneously during collapse and expansion.
[0045] The frame member 40 is preferably formed from a single piece of planar paperboard that is similar to the paperboard of the frame member 20 , preferably in a shape similar to that shown in FIG. 4 . Other suitable materials can be substituted. The member 40 also has cutouts 45 formed through the paperboard of a central area through which air will flow when the filter 10 is in use. The frame member 40 is slightly longer and wider than the frame member 20 so that the frame member 40 can be slid onto the frame member 20 in the manner of a gift box as shown in FIG. 12 .
[0046] After forming, the frame member 40 is folded and then glued to form side walls and end walls as shown in FIG. 10 , and then is folded along substantially parallel lateral score lines 41 , 43 and others to form the collapsed shape shown in FIGS. 1 and 2 . In order to fold the frame member 40 to a desired configuration, a series of folds are formed in the frame member, preferably by first scoring the frame member 40 along lines, such as the score lines 41 and 43 , among others, as shown in FIG. 9 . The score lines 41 and 43 , along with all other score lines formed in the frame member 40 , are conventional score lines as described above.
[0047] The frame member 40 is designed to mount to the frame member 20 with tabs in one member inserting into slots in the other member to retain the mounting condition. For example, as shown in FIG. 1 , the tabs 160 and 162 are formed on the top edges of the frame member's end wall 22 . Corresponding slots 170 and 172 are formed at the base of the junction of the end wall 42 and the central area of the frame member 40 . When the frame member 40 is placed over the frame member 20 , the tabs 160 and 162 are inserted in the slots 170 and 172 to fix the frame members 20 and 40 together, particularly against any force in the pleated media assembly 30 that tends to return the pleated media assembly 30 toward its collapsed condition.
[0048] Similar tabs are formed at the corners of the frame member 20 (see tabs 164 and 166 in FIG. 16 ) and slots are formed at the corners of the frame member 40 (see slots 174 and 176 in FIG. 16 ). When the frame member 40 is placed over the frame member 20 , the tabs 164 and 166 (along with other, similar tabs at the remaining corners) insert into the slots 174 and 176 , respectively (along with other, similar slots at the remaining corners), to fasten the frame member 40 to the frame member 20 .
[0049] In order to reduce the volume of the filter 10 prior to shipping, the combination of the frame member 20 and the pleated media assembly 30 is collapsed into a very compact structure in the configuration shown in FIGS. 1 , 2 , 3 , 5 and 7 . In order to accomplish this collapsed condition, the frame member 20 is folded along the score lines 21 and 23 , among others, with the end panels 32 and 34 of the pleated media assembly 30 attached to the end walls 22 and 24 . Thus, the end walls 22 and 24 remain substantially parallel to one another and to the end panels 32 and 34 , and the pleats of the assembly 30 are compacted between the two end walls 22 and 24 , as shown in FIGS. 1 , 2 , 3 and 7 .
[0050] During collapsing of the pleated media assembly 30 and the frame member 20 , the location of each panel of the pleated media assembly 30 is designed to fit within the collapsed frame member 20 , as will now be described with reference to the illustrations of FIGS. 3 through 6 . As shown in the illustrations, the frame member 20 has end walls 22 and 24 to which the end panels 32 and 34 , respectively, are mounted. One panel of the pleated media assembly 30 is inserted in the leftward most cavity of the frame member 20 , and the end panel 32 is attached to the underside (in the orientation shown in FIG. 6 ) of the end wall 22 . The remaining panels of the pleated media assembly 30 extend to the right in the orientation shown in FIG. 6 . The first panel 33 (see FIG. 3 , which is inverted relative to FIGS. 5 and 6 ) to the right of the end panel 32 extends over the frame member segments D, E, F and G, allowing the remaining panels of the pleated media assembly 30 to be held in a U-shaped channel formed by the end member segments B, C and D. The panel 34 extends from the large cluster of panels in the U-shaped channel to attachment to the end wall 24 of the frame member 20 . Most of the panels of the pleated media assembly are compressed and inserted in the U-shaped channel that forms a larger cavity in the frame member 20 . Preferably, there are no pleats of the pleated media assembly in the V-shaped channel rightward of the U-shaped channel, but the next rightward channel contains another panel of the pleated media assembly.
[0051] While the pleated media assembly 30 and the frame member 20 are collapsed in this configuration, the side walls 26 and 28 of the frame member 20 extend well beyond the lateral ends of the pleated media assembly panels. After expansion, the side walls 26 and 28 are bent upwardly to substantially perpendicular relative to the end walls 22 and 24 , as shown in the progress from FIG. 8 to FIG. 11 . It is preferred that during manufacture (and thus prior to expansion) of the combined frame member 20 and the pleated media assembly 30 , the frame end walls 22 and 24 are mounted to the frame side walls 26 and 28 using adhesive, fasteners or other suitable means. The overlapping portions of the end walls and sidewalls are folded parallel to the respective end walls 22 and 24 when the structure is in its collapsed state, and when the structure is expanded those overlapping portions fold out and are coplanar to the sidewalls 26 and 28 (and thus perpendicular to the end walls 22 and 24 ).
[0052] It should be understood that the number of channels in the frame member 20 with and without pleated panels will be determined by the size of the filter and could differ from that shown. For example, smaller filters of the same height would have less folding and no channels without panels. Although a U-shaped channel is described above as containing most of the pleated panels of the pleated media assembly 30 , it will become apparent to a person of ordinary skill that the shape of the channel containing the majority of the pleated panels is not critical. While the U-shaped channel has advantages, another shape could have most or many of those advantages while providing other advantages. Thus, a wide and deep V-shaped channel could be substituted for the U-shaped channel, as could a W-shaped channel or multiple adjacent or spaced V-shaped channels.
[0053] The collapsed configuration shown in FIGS. 1-3 allows the collapsed pleated media assembly 30 to be mounted in the collapsed frame member 20 during construction, and remain in this condition during shipping and subsequent storage of the components as long as the components are maintained in this condition, such as by bands, shrink wrap, boxes or any other suitable restraint. During expansion and assembly of the collapsed filter components, the frame member 20 and pleated media assembly 30 are expanded by longitudinal elongation. This can be accomplished by releasing the restraint on the collapsed combination and grasping the end walls 22 and 24 and manually forcing them apart from one another. This is carried out until the frame member 20 and pleated media assembly 30 reach a final length, which will be apparent due to the central area 27 attaining a substantially flat condition. The sidewalls 26 and 28 are then manually placed in the substantially perpendicular orientation relative to the central area 27 . The second frame member 40 is then placed over the frame member 20 in the manner of a gift box as shown in FIG. 12 and the two frame members 20 and 40 are pushed together to create the filter assembly shown in FIG. 15 .
[0054] When in the collapsed condition, the components of the filter 10 are packaged as tightly and small as feasible so that, during shipping and subsequent storage, they maintain their compact size and thus keep shipping and storage costs low. Once the filter 10 is removed from the packaging and expanded, the filter 10 consumes the same space of a conventional filter of its size, and operates to filter air in an HVAC system in a conventional manner—by filtering the air forced through the filter media thereof.
[0055] A preferred feature of the invention is flexible ribbons 290 (see FIGS. 3 and 11 ) of fabric, polymer strips, yarn or any other suitable flexible material that are attached, such as by adhesive, ultrasonic or thermal bonding or any other means, to the tips of the pleats where the edges of each pair of adjacent rectangular panels are joined. The ribbons 290 are used to maintain substantially consistent spacing between the tips of the pleats upon expansion, and to prevent excessive expansion of the pleated filter media assembly 30 . A person having ordinary skill will understand from this description that other filter media materials can be used that do not require such ribbons 290 , and that the ribbons 290 can be used on only one side of the pleated media assembly 30 . Alternatively, it will become apparent that other means of spacing can be used, such as extending string through openings in the pleated filtration media, providing a traditional finger-like pleat separator made out of paperboard or plastic, or any other suitable spacing methods or any other suitable attachment means.
[0056] An alternative embodiment of the present invention is shown in FIGS. 13 and 14 . The frame member 120 is substantially identical to the frame member 20 , with the exception of the panels 122 ′, 124 ′, 126 ′ and 128 ′ extending from the ends 122 and 124 and the sides 126 and 128 , respectively. Upon expansion of the frame member 120 from the collapsed to the elongated state, the panels 122 ′, 124 ′, 126 ′ and 128 ′ are bent over to a substantially perpendicular orientation relative to the side walls or end walls from which they extend. Each of the panels 122 ′, 124 ′, 126 ′ and 128 ′ is fastened at its ends to next adjacent panels, such as by adhesive or some other suitable fastener. This alternative embodiment has the advantage that no second frame member is required to retain the pleated media assembly within the frame, because the panels 122 ′, 124 ′, 126 ′ and 128 ′ retain the pleated media assembly once they are fastened in their final position.
[0057] As shown in FIGS. 17 and 18 , a guide 200 can be integrated into, or attached to, the sidewall 246 of a second frame member 240 . The second frame member 240 is preferably similar to the second frame member 40 , described above, inasmuch as it has a planar central area with openings for air flow, along with sidewalls and end walls substantially perpendicular to the central area and that frictionally engage the sidewalls and end walls of a frame member substantially similar to the member 20 described and shown herein. The second frame member's 240 sidewalls form the outer lateral surface of the finished filter, and, therefore, the guide 200 extends from one sidewall 246 to engage a rail 210 in a conventional HVAC system. The guide 200 thus maintains the attached filter within the conventional HVAC system and reduces air bypassing the filter.
[0058] An alternative, or complement, to the guide 200 is shown in FIGS. 18 and 19 . A flexible seal extension 300 is mounted at the top of the filter 310 on the upstream side and a similar flexible seal extension 302 is mounted at the bottom of the filter 310 on the upstream side. The seal extensions 300 and 302 are preferably either formed integral to the frame of the filter 310 , or are mounted thereto, such as by double-sided tape, adhesive or any suitable fastener. The seal extensions 300 and 302 are preferably substantially L-shaped and the cantilevered leg of each can pivot away from the filter 310 to contact an adjacent surface of the HVAC structure that holds the filter 310 , such as the floor 304 of the frame 306 (see FIG. 20 ) or the rail 308 . This contact forms an air seal and an angled air guide that greatly reduces the amount of air that would, without the seal extensions, otherwise bypass the filter 310 .
[0059] The seal extensions 300 and 302 are able to pivot relative to the filter 310 because the material of which they are constructed is deflected under the force of the air blowing through the structure holding the filter 310 . If the material of which the seal extensions 300 and 302 is more rigid than would alone permit sufficient deflection, a “hinge” can be formed at the juncture of the legs that permits the cantilevered leg of each seal extension to pivot relative to the leg attached to the filter 310 . Such a hinge is preferably formed by scoring the material of which the seal extension is constructed, but can also be formed by any known hinge.
[0060] In an alternative, the seal extensions 300 and 302 can be rigid and have no hinge to permit pivoting if they are constructed with precise size and orientation to seat against an adjacent surface to form a seal without such pivoting. Still further, seal extensions can be mounted to the downstream side of the filter 310 .
[0061] This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims. | A collapsible HVAC filter that includes a pleated filter media pack with ends that attach to ends of a planar filter frame member. The structure collapses by folding the filter frame member along score lines and compressing the pleated filter media while the media and frame member are attached. The collapsed components occupy little space relative to the expanded filter, and can be expanded to form a completed filter with little effort required by the end user. Most of the filter media is collapsed in a generally U-shaped channel formed from the folded filter frame member. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national stage entry under 35 U.S.C. 371 of PCT International Application PCT/US13/72367 filed on 27 Nov. 2013, which claims priority to U.S. Provisional Application Nos. 61/797,002, filed on Nov. 27, 2012, 61/797,006, filed on Nov. 27, 2012, and 61/797,024, filed on Nov. 27, 2012, all of which are incorporated herein by reference in their entireties.
FIELD OF THE INVENTION
[0002] The present disclosure relates to methods for sample preparation and quantitation of antigenic biomarkers on individual cells in a multiparametric cell analysis platform such as mass cytometry.
BACKGROUND
[0003] Comparison of primary neoplastic cells with control cells of same lineage has not been undertaken to show signaling nodes that are of particular significance due to high signaling activity in individual cell-types of myeloid neoplasms. Dynamic signaling states can be compromised when samples are cryopreserved. Thus, phospho-flow analysis performed on fresh samples can be theoretically more informative in identifying previously unidentified signaling aberrations than analysis performed on preserved samples.
[0004] Phospho-flow assays, which have typically been performed by fluorescent flow cytometry, have limitations due to the number of colors available per analysis tube. At best, fluorescent cytometry allows 18-20 markers to be evaluated simultaneously. However, overlap of fluorescence emission spectra requires set up of compensation settings that can often be time consuming. Further, tandem dyes can break down and emit signal at a different wavelength than expected, confounding results. Most commercial instruments are capable of analyzing less than 10 antibodies/tube. Thus, evaluating lineage markers and functional intracellular (IC) markers in a single tube assay has not been feasible. Multi-tube analysis can be time consuming and has precluded precise mapping of functional activity to cell-type, in particular rare cell-types (such as leukemic stem cells, dendritic cells, clonal T cells, etc.), some of which require at least 8-9 lineage- and cell type-determining surface markers (CD3, CD11c, CD14, CD19, CD33, CD34, CD45, CD117, CD123, etc.) for accurate identification based on presence or absence of markers. Fluorescent-labeled antibodies are generally more expensive and less stable than metal-tagged antibodies.
[0005] New methods are needed for analysis of large numbers of cell surface and intracellular markers simultaneously.
BRIEF SUMMARY OF THE INVENTION
[0006] In one aspect, a unique sample preparation method is provided for phos-flow analysis that incorporates a pre-fixation cooling step that lowers baseline signaling activity and results in a higher fold-change or distance between the induced and baseline state. A staining step for cell identification is performed prior to fixation. The method applies to modified samples that require surface staining for cell identification for applications that require use of live cells for further single cell analysis.
[0007] The method applies to cell lines, frozen or fresh mononuclear cells, fresh human samples, and any pathologic sample for biomedical research and to test novel inhibitors by cell-based pharmacoproteomic assays.
[0008] In another aspect, a sample preparation method is provided that allows fixation of a sample in its fresh state for baseline activity assessment. Simultaneous assessment of baseline signaling activities and cell identification is performed in the same experiment and applied for diagnostic and prognostic assays. The sample can be any human sample or solid tissue including blood, marrow, fine needle aspirates, and tissue biopsies comprised of a heterogeneous mixture of cells requiring cell-type identification. A strategy that combines a baseline evaluation by fresh sample fixation with surface staining performed post-fixation; and induced fold-change evaluation where surface staining is performed pre-fixation.
[0009] In another aspect, a novel combination of receptors and signaling markers is provided, including IL3R, IL7R, p-STAT5, p-STAT3, and p-p38 MAPK for identification of cells that have abnormally high signaling activities and based on their cell type can predict the cause of relapse, guide therapy, and prognosticate disease outcome. The sample can be any human sample or solid tissue including blood, marrow, fine needle aspirates, and tissue biopsies comprised of a heterogeneous mixture of cells requiring cell-type identification. This antibody panel applied in high throughput cytometry assays for prognostic and diagnostic evaluation and drug discovery in chronic myeloid leukemia, and other acute and chronic myeloproliferative leukemias, and Ph+ acute lymphoblastic leukemia.
[0010] In another aspect, data analysis methods are provided based on user selection of cell-types, ex vivo perturbations, functional readouts, etc. High dimensional plotting of select parameters generate patterns that allow interpretation of high throughput cytometry data and discover correlations such as between biochemical pathways and uncover underlying pathobiology. Cell type-specific proteomic profiles (mapping antigen expression profile to the identified cells) are provided that facilitate data interpretation through visualization of post-analysis data with simultaneous views showing cell proportions to demonstrate relative burden of disease. Quantitative data inclusive of cell fractions and expression levels of biomarkers allow comparison of datasets acquired from different time points to monitor therapy response. High dimensional plots based on selection of certain parameters that allow interpretation of high parameter datasets are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates cytokine-induced fold-change above baseline when using the pre-fixation staining method in chronic-phase CML patient compared to control for selected cell-types (a. monocytes, b. neutrophils, c. B cells, d. CD4 T cells, e. CD8 T cells, f. Basophils) and intracellular (IC) protein readouts (square: p-STAT5, circle: p-STAT3, triangle: p-p38 MAPK, and diamond: total IKB kinase). By this method, in myeloid lineage cells (neutrophils, monocytes, and basophils), all patient cells have higher IL3- and IFNα2-induced p-STAT5 compared to normal counterparts. In monocytes and CD4 T cells, IL6-induced p-STAT3 compared to normal control cells. These fold-change are less delineated in post-fixation staining method, in part due to high baseline activities in the latter method.
[0012] FIG. 2 depicts SPADE analysis performed for high dimensional clustering of cells to show differential induced STAT5 and STAT3 activities in the chronic phase CML blood sample. The analysis shows high induced IL3-STAT5 activity in cells arising from common myeloid progenitors (monocytes, myeloid DCs, neutrophils, basophils) and IL6-STAT3 activity in monocytes and CD4 T cells. Increased IL3-STAT3, STAT5 activity in CD33 hi cells (basophils and monocytes) suggests correlation between STAT5 activity and CD33 expression. IL3, IL6-STAT5 activity is a possible marker of CML (BCR-ABL+) clonal T cells, while IL6-STAT3 activity is high in all CD4 T cells.
[0013] FIG. 3 illustrates baseline activities for selected cell-types (a. monocytes, b. neutrophils, c. B cells, d. CD4 T cells, e. CD8 T cells, f. Basophils) and IC protein readouts (p-STAT5, p-p38 MAPK, and p-PLCg2) in patient compared to control, comparing pre-fixation and post-fixation staining methods. Baseline activities are lower by pre-fixation method where cooling the sample (while staining for surface markers) causes enzyme inactivation thus lowering baseline activities with a prominent effect in patient cells compared to normal possibly due to more labile factors in the metabolically active patient cells.
[0014] FIG. 4 illustrates lower baseline activities (represented by area below the dividing line in each bar) in patient cells compared to control cells, while the fold change (represented by area above the dividing line in each bar) is higher in patient cells compared to control cells using the pre-fixation method, while the post-fixation method failed to reveal a notable difference between induced change in the patient and healthy control cells.
[0015] FIG. 5 illustrates cell type-specific activities in select IC protein readouts due to IL3 induction. The analysis is based on pre-fixation data due to better signal to noise ratio for CD33 antigen expression. IL3-induced p-STAT5 and p-STAT3 activities in CML clonal cells appear to be correlated with CD33 and possibly CD123 expression.
[0016] FIG. 6 illustrates differential induced STAT5 activities in CD33+ and CD33− cells gated by using p-STAT5 v. CD33, and CD33 v. CD123 bivariate plots. The CD33− undifferentiated CML stem/progenitor cells had lower IL3- and IL6-induced upregulation compared to more differentiated cells, possibly due to constitutive activity, with lower reliance on cytokines from the inflammatory milieu.
[0017] FIG. 7 shows SPADE analysis of all cells, arrow points to rare CD33+/IL3R+ cells that have high baseline and IL3-induced activity.
[0018] FIG. 8 shows SPADE analysis of CD19+ cell fraction, capturing cells co-expressing CD33 and/or IL3R cells with high baseline and IL3-induced p-STAT5 activity, suggesting admixed multipotent progenitor cells with high IL3-STAT5. More mature B cells lack significant p-STAT5 activity.
[0019] FIG. 9 shows identification of cells with high p-STAT5 activity in the patient sample with relapsed CML, and illustrates gating strategy used to identify the lineages of p-STAT5 hi cells. Cells with high p-STAT5 activity levels were identified on CD45 v p-STAT5 bivariate plot. After identifying the CD34+ cells on CD34 v CD45 plot, CD19 v CD45 and CD3 v. CD45 plots were used for lineage identification of more differentiated CD34- or CD34 lo cells. p-STAT5 hi cells comprised of a mixture of CD19+/CD45 lo and CD3+/CD45+ lymphoid progenitors and rare CD34+/CD45 lo progenitor/stem cells.
[0020] FIG. 10 shows differential cell type-signaling activation in p-STAT hi CML stem/progenitor cells. It illustrates differential STAT5 and p38 MAPK, and IKB kinase activities within the individual p-STAT5 hi cell-types as compared to mature neutrophils and immature (L-shifted) neutrophils. Baseline p-STAT5 was low in mature neutrophils compared to L-shifted neutrophils suggesting loss of p-STAT5 as the myeloid lineage cells undergo final maturation and apoptosis. The p-STAT5 hi myeloid progenitor/stem cells had lower p38 MAPK and IKB kinase compared to the p-STAT5 hi lymphoid progenitor cells.
[0021] FIG. 11 shows a high dimensional data plot capturing select antigen expression profile in individual cell types displayed with relative cell frequencies. Cells with high IC activities included CD19+/CD45 lo /IL7R hi and CD3+/CD45+/IL-7R lo lymphoid progenitors and less frequent CD34+/CD117+/IL7R−/IL3R lo myeloid progenitor/stem cells.
[0022] FIG. 12 illustrates mass cytometry data in high dimensional SPADE views to capture expression level of selected readouts in all cells of whole blood with relapsed CML. It illustrates high baseline p-STAT5 activity in lymphoid correlated with p-STAT3 and p-38 MAPK activities and total IKB levels.
[0023] FIG. 13 SPADE analysis view of p-STAT5 hi subpopulations shows the CD127 lo stem/progenitor cells had relatively high pS6 kinase activity suggestive of mTOR activation.
DETAILED DESCRIPTION
[0024] Methods and novel combinations of antibodies are provided for simultaneous quantitation of antigenic biomarkers in individual cells. Cell-based assays are provided to measure early, residual, or relapsed disease states for therapy guidance and to assess the biologic effects of ex vivo perturbations. Proteomic profiles that emerged from the data provided herein allow for prediction of therapeutic outcome and therapy responsiveness. Deregulated protein expression and activation profiles in certain cell-types (effector and memory T cells, neoplastic clones, NK cells, dendritic cells, etc.) of heterogeneous cellular mixtures (blood, bone marrow, mononuclear cells, body fluids, fine needle aspirates, core needle biopsy, etc.) are determined by a next-generation highly multiparametric cell analysis platform such as mass cytometry.
[0025] Using mass cytometry, a combination of markers was identified that is not routinely applied in diagnostics or for minimal residual disease (MRD) identification. A larger number of cell-identification markers used simultaneously than what is typically done allowed identification of rare stem/progenitors of both myeloid and lymphoid lineages. Routine MRD analysis does not incorporate signaling markers, essentially critical functional activity markers of neoplastic cells. The limitations of fluorescence flow, as described above, have precluded routine analysis of signaling activity. In addition, signaling states are highly dynamic and must be captured within a certain window of time after sample collection. Typically, overnight shipment of a blood or marrow sample, as is routine practice for most commercial laboratories, is not suited for analysis of signaling networks in fresh state. However, fixing the sample soon upon collection can be a way to circumvent this issue.
[0026] Expression levels of certain regulatory proteins within key pathways of convergence in target cell populations can predict disease states, unravel therapeutic targets and provide guidance for clinical decision-making. These cell-based “biomarkers” can be various receptors and/or downstream effectors with key biologic functions such as maturation, proliferation, DNA repair, apoptosis, etc., and may react to stimuli such as hypoxia, oxidative stress, and external growth factors. In disease states, many normal functions are affected and can be measured by altered protein levels or activation states.
[0027] As such, biomarker profiling of signaling pathways can generate response signatures associated with certain disease states for risk-stratification and outcome prediction, enabling personalized care and drug discovery. Innovative combinations of antibodies were designed for identification of cellular subsets of biomarkers including multilineage tumor clones and immunologic subsets, and quantitation of selected signaling biomarkers for cell type-specific biologic behavior was performed. Cell type-specific proteomic signatures associated with molecular relapse due to therapy non-adherence were identified, resulting in a cost-effective cell-based prognostic assay. Further, blood analysis allows for a non-invasive monitoring of therapy response and non-adherence.
[0028] Cytokine induction can enhance detection of signaling activity particularly for cells that are not rapidly multiplying and have relatively low baseline activity. In routine phospho-flow analysis, cytokine induction is followed by fixation of cells. However, fixation can compromise the integrity of antibody-binding sites and can render suboptimal staining results. In addition, distinction between baseline and induced activity can be masked by high baseline activity preserved by immediate fixation and readily detectable. A method where sample is allowed to cool while staining allows for both staining of live cells with preservation of antibody-binding sites, and simultaneous capture of induced signaling activity while lowering of baseline activity.
[0029] The protocol described here for cytokine-induced testing of signaling states includes a pre-fixation surface staining method. This method may be used for cell-specific signaling network analysis to assess the biologic effects of ex vivo perturbations that modify downstream proteins in a way in which their expression or activity level changes. Often changes in one key protein leads to a cascade of changes in downstream proteins, which may have important functional significance. Thus, multiple functional readouts are feasible and are informative in pharmacoproteomic assays.
[0030] Data visualization strategies are necessary to build predictive and explanatory models from high dimensional data derived from cytometry assays that are used to guide clinical management. The strategies allow selection of parameters based on variance in the dataset to generate correlative patterns associated with clinical situations such as medication non-adherence and may further predict effectiveness of targeted treatments for individual patients. Plots simultaneously showing expression of signaling markers in different signaling pathways within individual cell types can create cell type specific patterns, allowing identification of previously unknown correlations and cell-cell interactions. These are useful in communicating data to the medical and research community for optimal patient management.
[0031] Unless defined otherwise herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Singleton, et al., Dictionary of Microbiology and Molecular Biology , second ed., John Wiley and Sons, New York (1994), and Hale & Markham, The Harper Collins Dictionary of Biology , Harper Perennial, NY (1991) provide one of skill with a general dictionary of many of the terms used in this invention. Any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention.
[0032] The practice of the present invention will employ, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, and biochemistry, which are within the skill of the art. Such techniques are explained fully in the literature, for example, Molecular Cloning: A Laboratory Manual , second edition (Sambrook et al., 1989); Oligonucleotide Synthesis (M. J. Gait, ed., 1984; Current Protocols in Molecular Biology (F. M. Ausubel et al., eds., 1994); PCR: The Polymerase Chain Reaction (Mullis et al., eds., 1994); and Gene Transfer and Expression: A Laboratory Manual (Kriegler, 1990).
[0033] Numeric ranges provided herein are inclusive of the numbers defining the range.
[0034] Unless otherwise indicated, nucleic acids are written left to right in 5′ to 3′ orientation; amino acid sequences are written left to right in amino to carboxy orientation, respectively.
DEFINITIONS
[0035] “A,” “an” and “the” include plural references unless the context clearly dictates otherwise.
[0036] “Mass cytometry” refers to a single-cell multiparametric protein detection technology. Antibodies are tagged with isotopically pure rare earth elements, allowing simultaneous measurement of greater than 40 parameters while circumventing the issue of spectral overlap which is observed with fluorophores. The multi-atom metal tags are ionized, for example by passage through an argon plasma, and then analyzed by mass spectrometry. See, e.g., Bandura et al. (2009) Analytical Chemistry 81(16):6813-6822; Ornatsky et al. (2010) Journal of Immunological Methods 361(1-2):1-20; Bendall et al. (2011) Science 332(6030):687-696.
[0037] “SPADE” refers to “Spanning-tree Progression Analysis of Density-normalized Events.” SPADE clusters phenotypically-similar cells into hierarchy that allow high-throughput, multidimensional analysis of heterogeneous samples. See, e.g., Qiu et al. (2011) Nat. Biotechnol. 29(10): 886-91.
[0038] “Phospho-flow” or “phos-flow” analysis refers to use of flow cytometry to analyze phosphorylated intracellular molecules at the single cell level, such as, for example, phosphorylated signaling proteins and cytokines.
[0039] An “antibody” is an immunoglobulin molecule capable of specific binding to a target, such as a carbohydrate, polynucleotide, lipid, polypeptide, etc., through at least one antigen recognition site, located in the variable region of the immunoglobulin molecule. As used herein, the term encompasses not only intact full-length antibodies, but also fragments thereof (such as Fab, Fab′, F(ab′) 2 , Fv), single chain (ScFv), mutants thereof, fusion proteins comprising an antibody portion, and any other modified configuration of the immunoglobulin molecule that comprises an antigen recognition site of the required specificity. An antibody includes an antibody of any class, such as IgG, IgA, or IgM (or sub-class thereof), and the antibody need not be of any particular class. Depending on the antibody amino acid sequence of the constant domain of its heavy chains, immunoglobulins can be assigned to different classes. There are five major classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2. The heavy-chain constant domains that correspond to the different classes of immunoglobulins are called alpha, delta, epsilon, gamma, and mu, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known.
[0040] A “monoclonal antibody” refers to a homogeneous antibody population wherein the monoclonal antibody is comprised of amino acids (naturally occurring and non-naturally occurring) that are involved in the selective binding of an antigen. A population of monoclonal antibodies (as opposed to polyclonal antibodies) is highly specific, in the sense that they are directed against a single antigenic site. The term “monoclonal antibody” encompasses not only intact monoclonal antibodies and full-length monoclonal antibodies, but also fragments thereof (such as Fab, Fab′, F(ab′) 2 , Fv), single chain (ScFv), mutants thereof, fusion proteins comprising an antibody portion, and any other modified configuration of the immunoglobulin molecule that comprises an antigen recognition site of the required specificity and the ability to bind to an antigen (see definition of antibody). It is not intended to be limited as regards to the source of the antibody or the manner in which it is made (e.g., by hybridoma, phage selection, recombinant expression, transgenic animals, etc.).
[0041] “Fv” is an antibody fragment that contains a complete antigen-recognition and binding site. In a two-chain Fv species, this region consists of a dimer of one heavy and one light chain variable domain in tight, non-covalent association. In a single-chain Fv species, one heavy and one light chain variable domain can be covalently linked by a flexible polypeptide linker such that the light and heavy chains can associate in a dimeric structure analogous to that in a two-chain Fv species. It is in this configuration that the three CDRs of each variable domain interact to define an antigen-binding specificity on the surface of the VH-VL dimer. However, even a single variable domain (or half of a Fv comprising only 3 CDRs specific for an antigen) has the ability to recognize and bind antigen, although generally at a lower affinity than the entire binding site. A “Fab” fragment also contains the constant domain of the light chain and the first constant domain (CH1) of the heavy chain. Fab′ fragments differ from Fab fragments by the addition of a few residues at the carboxy terminus of the heavy chain CH1 domain including one or more cysteines from the antibody hinge regions.
[0042] An epitope that “specifically binds” or “preferentially binds” (used interchangeably herein) to an antibody is a term well understood in the art, and methods to determine such specific or preferential binding are also well known in the art. A molecule is said to exhibit “specific binding” or “preferential binding” if it reacts or associates more frequently, more rapidly, with greater duration and/or with greater affinity with a particular cell or substance than it does with alternative cells or substances. An antibody “specifically binds” or “preferentially binds” to a target if it binds with greater affinity, avidity, more readily, and/or with greater duration than it binds to other substances. For example, an antibody that specifically or preferentially binds to an epitope is an antibody that binds this epitope with greater affinity, avidity, more readily, and/or with greater duration than it binds to other epitopes. It is also understood by reading this definition that, for example, an antibody (or moiety or epitope) that specifically or preferentially binds to a first target may or may not specifically or preferentially bind to a second target. As such, “specific binding” or “preferential binding” does not necessarily require (although it can include) exclusive binding. Generally, but not necessarily, reference to binding means preferential binding.
[0043] A “variable region” of an antibody refers to the variable region of the light chain or the variable region of the heavy chain, either alone or in combination.
[0044] “Complementarity determining region” (CDR) refers a relatively short amino acid sequence found in the variable regions of antibody molecules. The CDRs contain amino acid residues that determine the specificity of antibody molecules and make contact with a specific antigen.
Methods for Assessing Ex Vivo Perturbations of Cell Populations
[0045] Methods are provided for assessing effects of ex vivo perturbations on signaling pathways in cells of mixtures, such as heterogeneous biologic mixtures.
[0046] The disclosed methods may be used for analysis of alterations in regulatory proteins and their activation status due to external perturbations. For example, the method may be used in conjunction with phos-flow analysis of phosphorylation states.
[0047] In some embodiments, the method is a modification of standard phos-flow approach (e.g., where the cells are stained post-fixation and there is no cooling step prior to fixation). In contrast, the methods disclosed herein allow exaggeration of biologic effects due to external stimuli by cooling the sample, which quenches baseline (pre-stimulation) activity levels. Levels of certain biomarkers within modified signaling networks are determined in cell-types of interest. The data capture platform is a highly multiplexed cell analysis platform such as a mass cytometer.
[0048] A mixture of cells (e.g., a heterogeneous mixture of cells, such as blood, bone marrow, body fluids) is exposed to an exogenous stimulus (such as interleukins or hormones) that alters signaling, +/− an inhibitor that potentially alters cellular responses to modulators. The exogenous stimulus may include, but is not limited to, IL3, IL6, IFNα2, PMA, ionomycin, IFN-g, LPS, interleukins, SCF, FLT3L, GM-CSF, G-CSF, EPO, and/or TPO. The modified sample is then reacted with antibodies that bind to cell surface biomarkers, such as lineage-associated and other surface markers on ice. No stimuli (constitutive signaling) or drug inhibitor+ stimulator(s) may also be assessed. The sample is then fixed and permeabilized, and further reacted with antibodies towards intracellular markers.
[0049] The method may be conducted as follows:
1. The sample is exposed to one or more modulator(s) at a first temperature (e.g., 37° C.). 2. The modulated sample is then contacted with a panel of antibodies directed towards surface antigens at a second temperature that is lower than the first temperature (e.g., 0° C., for example, on ice). 3. The sample is subjected to fixation and permeabilization and is contacted with a panel of antibodies that bind intracellular antigens. 4. Data is captured on a multiparametric cell analysis platform and analyzed further using flow analysis and high-dimensional data analysis algorithms. Thus, comprehensive biomarker response profiles are generated for cell-specific effects of signaling modulators and test compounds.
[0054] In Example 1, lowering of baseline and more dramatic fold-change with the pre-fixation method disclosed herein is demonstrated, compared to the traditional post-fixation staining approach. The individual subpopulations are better delineated in the pre-fixation staining approach due to better preservation of surface epitopes.
[0055] Fixation of the cells may be performed with any reagent that is suitable for inactivation of enzymes, including but not limited to kinases, phosphatases, and proteases, in order to “fix” the in vivo state of phosphorytlation. In some embodiments, a paraformaldehyde-based fixative is used, such as Phosflow Lyse/Fix buffer, available from BD. In some embodiments, a formaldehyde-based fixative is used. Permeabilization of cells may be performed, for example, with an organic solvent, a detergent such as Triton X-100, or saponin. In some embodiments, fixation and permeabilization are performed simultaneously. In other embodiments, fixation and permeabilization are performed sequentially. In other embodiments, cells are not fixed but cooled and further analysis of a modified cell state is performed of live cells.
[0056] The methods described herein may be deployed with any suitable multiparametric cell analysis technique, including but not limited to, mass cytometry, multiplexed fluorescent flow cytometry, multiplexed immunohistochemistry, immunocytochemistry, and multiplexed qRT-PCR, e.g., any technique that is capable of use for quantification of single cell expression of a combination of analytes. Readouts) may include any post-translational modification due to a disease state (e.g., oncogenic disease state) or induced perturbed state, including, but not limited to, phosphorylation or acetylation.
[0057] In some embodiments, staining of a sample such as whole blood prior to fixation eliminates two wash steps which would have to be performed to remove fixative if fixation were performed prior to staining.
[0058] In some embodiments, some residual phosphatase activity during the cooling step may cause dephosphorylation, so the absolute level of phosphoproteins may be lower than observed in a post-fixation staining method.
Combinations of Cellular Markers for Multiparametric Analysis of Cell Populations
[0059] Combinations of cellular markers and antibodies directed thereto are disclosed herein, which may be used, for example, for prognostic evaluation, outcome prediction, and therapy guidance in disease states. Combinations of antibodies disclosed herein may be used for simultaneous quantitation of antigenic biomarkers in individual cells.
[0060] Proteomic profiles that emerge from analysis of data generated for the combinations of biomarkers disclosed herein may allow for outcome prediction and therapy responsiveness. Deregulated protein expression and activation profiles in certain cell-types of cellular mixtures, such as heterogeneous cellular mixtures (e.g., blood, bone marrow, mononuclear cells, body fluids, fine needle aspirates, core needle biopsy, etc.) may be determined by highly multiparametric cell analysis platforms such as mass cytometry.
[0061] Combinations of antibodies are disclosed herein for identification of cellular subsets such as tumor sub-clones and immunologic subsets, and quantitation of selected biomarkers for cell-type specific biologic behavior. Biological features associated with unfavorable clinical factors may be identified leading to further research and development of cost-effective prognostic assays. For example, activated signaling networks in therapy-resistant subpopulations can guide further therapy by identifying survival pathways that can be more specifically targeted.
[0062] Antibodies directed to the following combination of biomarkers identified stem/progenitor cell subpopulations in the peripheral blood of a patient previously treated for chronic myelogenous leukemia who had been off therapy for 2 months: CD4-145Nd, CD20-147Sm, CD15-148Nd, CD7-149Sm, CD3-150Nd, CD123-151Eu, CD27-152Sm, CD45RA-153Eu, CD45-154Sm, CD19-156Gd, p-p38-157Gd, CD127-158Gd, CD11c-159Tb, CD14-160Gd, IgD-161Dy, p-ERK1/2-162Dy, IKBtot-163Dy, pSTAT3-164Dy, pS6 kinase-165Ho, CD16-166Er, CD38-167Er, CD24-168Er, CD117-169Tm, CD8a-170Er, CD66-171Yb, pSTAT5-172Yb, CD34-173Yb, HLA-DR-174Yb, CD56-175Lu, CD33-176Yb. In Example 2, a unique combination of markers, including CD19, CD34, CD117, and CD127/1L-7R identified therapy-refractory subpopulations with activated p-STAT5 and p-38 MAP kinase, which could predict relapse. This combination of markers allows for cell-specific biomarker assessment that is of prognostic and therapeutic relevance.
[0063] In various embodiments, combinations of antibodies directed to subsets of the biomarkers disclosed above may be used for analysis of various cell populations and samples, for analysis of disease states, determination of cell lineage and/or maturation, prediction of therapeutic outcomes, and/or analysis of therapeutic effectiveness.
[0064] The following examples are intended to illustrate, but not limit, the present disclosure.
EXAMPLES
Example 1
Materials and Methods
[0065] A fresh whole blood sample from a 54-year-old adult male patient with chronic-phase chronic myelogenous leukemia (CML) who presented with neutrophilic leukocytosis with a total WBC: 33.3 K/μl (PMN: 17.98 K/μl, Lymphocytes: 3.66 K/μl, Monocytes: 0.33 K/μl, Eosinophils: 0.67K/μl, Basophils: 4.0 K/μl, immature granulocytes: 6.3 K/μl, Blasts: 0.33 K/μl), Hb: 15.8 g/dL, Hct: 47.9%, and PLT: 536 K/μl was obtained from UCSF Helen Diller Family Comprehensive Cancer Center with informed consent. Cell-specific cytokine-induced effects in the leukemic v. normal state were compared. The sample was exposed to: IL3 (50 ng/ml), IL6 (50 ng/ml), IFNα2 10,000 IU/ml or no stimulus, for 15 min at 37° C.
[0066] Using the pre-fixation surface staining method, the modulated samples were then contacted with a cocktail of antibodies towards surface antigens for 15 minutes on ice, followed by fixation with Phosflow Lyse/Fix reagent (BD Biosciences, San Jose, Calif.) 10 minutes at 37° C., and washed 2× with “wash buffer” (PBS 0.1% BSA, 2 mM EDTA, 0.05% azide) by centrifugation at 500×g for 5 minutes.
[0067] Using post-fixation surface staining, a set of patient and healthy control samples was fixed immediately after the cytokine stimulation with BD Phosflow lyse/fix reagent for 10 min at 37° C. and washed 2× in wash buffer, followed by surface staining for 30 minutes at room temperature and washed 2× with wash buffer.
[0068] A panel of 27 metal-tagged antibodies was constructed using Maxpar polymers and lanthanide metals as per the manufacturer's conjugation protocol (DVS Sciences, CA). Surface staining was performed with the following antibodies against 1) lineage-determining antigens: CD8a-144Nd, CD4-145Nd, CD20-147Sm, CD16-Nd148, CD45-154Sm, CD11c-159Tb, CD14-160Gd, CD33-166Er, CD24-168Er, CD3-170Er, CD66-171Yb, CD56-175Lu; 2) activation- and maturation-associated antigens: CD27-152Sm, CD45RA-153Eu, IgD-161Dy, CD38-167Er, HLA-DR-174Yb, CD25-176Yb; and 3) cytokine receptors: IL3R/CD123-151Eu. After 2× wash in wash buffer, both sample sets (prepared by pre-fixation and post-fixation surface staining methods) were resuspended and permeabilized with 100% methanol, washed 2× in wash buffer, and labeled for analysis of select intracellular antigens using the following antibody conjugates: pp38 MAPK-157Gd, total IKB-163Dy, pSTAT3-164Dy, pSTAT1-169Tm, pSTAT5-172Yb, pPLCγ2-173Yb. After 1× wash, the samples were treated with DNA Iridium intercalator for a final concentration of 1:2000. The data were captured by inductive coupled time-of-flight cytometry (CyTOF) and analyzed by traditional gating tools and high dimensional data analysis algorithms including Spanning Tree Progression of Density Normalized Events (SPADE).
Results
[0069] As compared to normal cell counterparts in the healthy control sample, CML cells in chronic phase had the following features:
[0070] A marked potentiated effect of IL3 on p-STAT5 in CML cells of myeloid lineage (neutrophils, monocytes, and basophils) was observed compared to majority of the lymphocytes in CML, rendering IL3-STAT5 a putative marker of neoplastic myeloid cells and possibly BCR-ABL positivity. IL6-STAT3 in CD4 T cells and monocytes likely represent immune response in CML ( FIGS. 1 and 2 ).
[0071] Baseline signaling activity levels were more prominent in post-fix surface staining methods due to preservation of signaling activity through fixation. By pre-fixation surface staining, all patient cells had lower baseline than control, except pPLCγ2 readout in Basophils. Thus, pre-fixation surface staining caused lowering of baseline IC readouts in patient cells, suggestive of quenching of baseline phosphorylation possibly due to inactivation of enzymatic activity during cooling, with relative preservation of effects due cytokine induction. By post-fixation surface staining, CML monocytes, B-cells, and basophils have higher baseline than control, consistent with capture of high baseline activities in active state due to fixation prior to staining. CML PMNs had lower baseline compared to control (possibly due to reduction of STAT5 activity due to apoptosis). Slightly higher baseline p-STAT5 in CD4 T cells suggests admixed clonal CML T cells in the CD4 T cell subset ( FIG. 3 ).
[0072] Fold-change (log 10 induced−log 10 basal) representing differential in the baseline and induced activity was higher in the pre-fixation surface staining method, possibly due to relative preservation of induced activity while quenching of baseline activity level due to enzyme inactivation in the cooling step. Elevated IL3-STAT5 in myeloid cells, and IL6-STAT3 in monocytes was observed in CML compared to healthy control cells when tested using the pre-fixation method as compared to the post-fixation method ( FIG. 4 ). Thus, pre-fixation surface staining can unravel subtle post-translational modifications (which may be masked due to high baseline activity or poor preservation of low density lineage-determining antigen epitopes in the post-fixation staining method) induced due to ex vivo perturbations. Also, CD33+ subset was not as well distinguished in the post-fixation surface staining method due to non-specific and lowering intensity of CD33 signal ( FIG. 7 ).
[0073] Differential cytokine-induced activity in CML cells based on stage of maturation with less differentiated (or multipotent progenitors) having lower growth factor responsiveness than more differentiated cells. Growth factor responsiveness could thus correlate with response to enzyme-targeted therapies that inhibit receptor-mediated signaling pathways.
[0074] Delineation of CD33 hi and CD33 lo cells, performed by extracting cell subsets from the pre-fixation surface staining data set, demonstrated correlation between CD33 and IL3-STAT5 activity ( FIG. 5 ).
[0075] Lower IL3- and IL6-induced STAT5 responses in CD33− multipotent CML stem/progenitor cells (with high baseline p-STAT5 activity) ( FIG. 6 ), suggests lower growth factor responsiveness (presumably due to BCR-ABL independent signaling activity) in treatment-refractory stem/progenitor cells. Thus cytokine-induced STAT5 activity could be a marker for TKI responsiveness useful for drug screening assays. Thus, drugs that increase the cytokine-response in stem/progenitor cells could be of therapeutic benefit in treated relapsed/refractory disease.
[0076] A minute CML myeloid progenitor subset (0.52%) with both high baseline and IL3-induced p38 MAPK and pSTAT5 activities (relative to more mature myeloid cells) correlated with CD27 and IL3R/CD123 expression ( FIG. 7 ).
[0077] CD19+ cell subsets had higher baseline and IL3- and IL6-induced STAT5 activity when co-expressing CD33 or CD123 myeloid markers, suggesting cells that are derived from the BCR-ABL (+) CML clone ( FIG. 8 ). Similar cells are likely to be found in other Ph+ leukemia (including B-ALL and biphenotypic leukemia). Thus, CD19+/CD33+ and/or CD19+/CD123+ cells with activated STAT5 networks likely represent clonal BCR-ABL (+) cells in Ph+ leukemia, and CD19+ cells that are CD123+ or CD33+ and p-STAT5 hi could be used for cell-based functional assays for detection of residual or relapsed disease.
Example 2
Materials and Methods
[0078] A fresh blood sample from a 74-year-old adult male patient previously on a BCR-ABL1 inhibitor for chronic-phase CML who presented with a normal total WBC: 7.9 K/μl (PMN: 3.43 K/μl, Lymphocytes: 3.41 K/μl, Monocytes: 0.82 K/μl, Eosinophils: K/μl, Basophils: K/μl, immature granulocytes: 6.3 K/μl), Hb: 14.1 g/dL, Hct: 40.7%, and PLT: 177 K/μl was obtained from UCSF Helen Diller Family Comprehensive Cancer Center with informed consent. Relapse due to non-adherence to therapy was suspected based on a BCR-ABL1/ABL1 p210 ratio of 0.285. The unmodified (baseline) sample was fixed in the BD Phosflow lyse/fix buffer 4 hours post-collection, washed with wash buffer, and stained with a panel of metal-conjugated antibodies. Surface staining was performed with antibodies against 1) lineage-determining antigens: CD4-145Nd, CD20-147Sm, CD15-148Nd, CD7-149Sm, CD3-150Nd, CD45-154Sm, CD19-156Gd, CD11c-159Tb, CD14-160Gd, CD16-166Er, CD24-168Er, CD117-169Tm, CD8a-170Er, CD66-171Yb, CD34-173Yb, CD56-175Lu, CD33-176Yb; 2) activation- and maturation-associated antigens: CD27-152Sm, CD45RA-153Eu, IgD-161Dy, CD38-167Er, HLA-DR-174Yb; and 3) cytokine receptors: IL3R/CD123-151Eu, IL7R/CD127-158Gd. The sample was permeabilized with 100% methanol −80° C. overnight, washed 2× in wash buffer, and labeled for analysis of select intracellular antigens using the following antibodies: pp38 MAP kinase-157Gd, pERK-162Dy, pSTAT3-164Dy, ppS6 kinase-165Ho; pSTAT5A-172Yb; and total IKB-163Dy for 30 minutes at RT. After 1× wash, the sample was treated with DNA Iridium nucleic-acid intercalator for a final concentration of 1:2000. The data were captured on CyTOF and analyzed by traditional gating tools and high dimensional data analysis algorithms including Spanning Tree Progression of Density Normalized Events (SPADE).
Results
[0079] In CML relapse due to non-adherence, the following observations were made:
[0080] By using CD45 and p-STAT5 bivariate plot, clusters of p-STAT hi cells were identified. Further bivariate gating revealed two minor lymphoid subpopulations—CD19+/CD20−/IgD−/CD66−/CD34 lo /CD45 lo progenitor cells (0.36%) and CD3+/CD4+/CD45+ T lymphocytes (0.24%)—with markedly high basal STAT5 and p38 activity that correlated with IL7R/CD127 expression such that IL7R− mature lymphocytes lacked high STAT5 or p38 MAPK activity levels ( FIGS. 9-12 ). A minute myeloid blast population (p-STAT5 hi /IL3R+/IL7R lo /CD34+/CD117+, 0.06%) was detected, with 2× lower p-38 MAPK activity and 3× lower IKB compared to the p-STAT5 hi /IL-7R+ lymphoid progenitors ( FIG. 10 and FIG. 13 ). The data suggest a role of IL-7R in receptor-mediated p-STAT5 and p-38 MAPK activation, with IL7R+/pSTAT5 hi /p38MAPK hi lymphoid cells and IL3R+/pSTAT5 hi /CD34+/CD117+ myeloid cells as potential cell-based biomarkers of relapsed CML and other myeloid neoplasms. Further, CD19+/IL7R+/pSTAT5 hi /p38MAPK hi lymphoid cells are likely BCR-ABL(+) and could represent a biomarker for residual/relapsed disease in Ph+ leukemias (including Ph+ B-ALL and biphenotypic leukemia) or early detection of B-lymphoid blast crisis of CML. Additionally, the ratio of CD19+/pSTAT5 hi /p38MAPK hi and CD3+/pSTAT5 hi /p38MAPK hi cells identified with this approach could have prognostic relevance.
[0081] IL3R helps distinguish the myeloid stem/progenitor cells in myeloid neoplasms (MPN, AML, MDS, myelodysplastic/myeloproliferative overlap syndromes) from normal physiologic stem/progenitor cells, and here elevated pS6 kinase activity suggests constitutive mTOR activation in IL3R+ cells ( FIG. 13 ). In this case, the data provide evidence of relapsed leukemia based on cell type-specific functional activity. Thus, assays based on the above combination of markers are useful in detection of residual or early myeloid neoplasms. The assay can be formulated for single tube high parameter analysis necessitating fewer cells than typical multiparameter flow cytometry assays.
[0082] Data visualization algorithms help visualize modifications in select parameters and cell-types due to certain select perturbations, enabling high throughput data analysis and interpretation based on abnormal activation patterns.
Interpretation
[0083] Differential response to cytokine activation provided evidence for the role of pro-inflammatory milieu that favors myeloid maturation over lymphoid development in CML. The data provided support for the STAT5 pathway as a potential drug target in myeloid neoplasms including BCR/ABL-positive chronic myelogenous leukemia and BCR/ABL− negative chronic myeloproliferative neoplasms (such as primary myelofibrosis), acute myeloid leukemia; and Ph+ B-lymphoblastic or biphenotypic leukemias. Cytokine responsiveness in stem/progenitor cells is a possible indicator of therapy responsiveness based on their known refractoriness to TM-targeted inhibition and data supporting low cytokine responses.
[0084] Cytokine-induced effects on STAT5 activity as measured by the mass cytometry assay can be used as a biomarker for response to STAT inhibition, and could serve as a biomarker for response to inhibition of BCR-ABL, an established drug target upstream of STAT pathways. Given the crucial role of IL6, a gene regulated by BCL6 in CML pathogenesis, the data raised doubt on the efficacy of BCL6 repression.
[0085] Detection of rare cells with elevated STAT5 and p38 MAPK activity with possible signaling through IL-7R suggests importance of these survival pathways in CML.
[0086] Whether STAT5 activity correlates with BCR/ABL expression in these cells, and potential therapeutic relevance of rare circulating IL-7R+ immature cells remains to be elucidated. Furthermore, high STAT5 activity in a rare IL-7R+ T-cell subset could represent an immune escape mechanism or a survival mechanism maintaining chronicity. Thus, for minimal residual disease detection in a case of a clonal neoplasm such as CML, T lymphoid progenitors with abnormal activity levels can be detected and are of potential prognostic relevance.
[0087] Although the foregoing invention has been described in some detail by way of illustration and examples for purposes of clarity of understanding, it will be apparent to those skilled in the art that certain changes and modifications may be practiced without departing from the spirit and scope of the invention, which is delineated in the appended claims. Therefore, the description should not be construed as limiting the scope of the invention.
[0088] All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entireties for all purposes and to the same extent as if each individual publication, patent, or patent application were specifically and individually indicated to be so incorporated by reference. | Methods for preparation of cells for analysis of biomarkers are disclosed. In one aspect, the method for preparation of cells for analysis of biomarkers includes contacting a sample that contains a population of cells with at least one modulating substance at a first temperature, thereby producing a modulated cell population; contacting the modulated cell population with at least one antibody that is directed to a cell surface biomarker at a second temperature that is lower than the first temperature, thereby producing an extracellularly stained cell population; and contacting the extracellularly stained cell population with one or more reagents that fixes and permeabilizes the cells, thereby producing a fixed and permeabilized cell population. | 6 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] This invention relates to laundry accessories and, more particularly, to novel systems, methods, and tools to keep socks matched during laundering.
[0003] 2. Background Art
[0004] Laundry is a perennial activity in most households. Also, socks are historically difficult match. This is not simply because they sometimes look somewhat alike, but a greater problem. Typically, socks are a comparatively small article of clothing. They are often colored, sometimes is not. They often contain synthetic fabrics such as nylon, polyester, spandex, other elastic, and so forth. These and even natural fibers, such as wool, often generate static cling. This puts socks in the position of being captured by other articles placed in the laundry load with socks, whether “whites” or “colors.”
[0005] In colors will be found shirts, towels, and other comparatively larger objects. In whites may be found linens, towels, underclothing, and so forth. Static buildup during the drying process may cause small articles of clothing to cling to other articles, and not separate.
[0006] For example, towels or t-shirts may be withdrawn from a tumbling dryer and put in another basket for, or as part of, sorting. It is completely within the realm of contemplation that a towel may be folded with a sock clinging to the backside. Thus, the sock is not seen, does not produce a noticeable bulge, and is not found until the towel is removed from a linen closet for use.
[0007] Thus, by such modes and many others, socks may become separated from one another, and such as been the case forever. Unmatched socks are the bane of the laundry function in any household. Moreover, some socks are apparently never found. A lone sock may sit in a drawer waiting a mate for months or years. Thus, there exist common jokes about how gremlins reach into the washing process and remove one out of every two socks in a pair. Of course this is not true. However, such jokes illustrate the ubiquitous nature and severity of the frustration from the problem.
[0008] Thus, it would be an advance in the art to find a simple system and mechanism for binding two socks of a pair together reliably and releasing them readily on demand. It would be an advance in the art if this system and mechanism could function equally well in a wash cycle and a drying cycle. For example, dryers operate at comparatively very high temperatures over 250 degrees Fahrenheit (115 degrees C.) in order to vaporize water to evaporate out of the fabric of clothing being dried.
[0009] Meanwhile, agitation, detergents, and the water are problematic for metals. Thus, resistance to chemical attack, corrosion, and the like may be important for protection of the system and device. This may also be a concern so that socks are not stained by rust or other oxidation of metals.
BRIEF SUMMARY OF THE INVENTION
[0010] In view of the foregoing, in accordance with the invention as embodied and broadly described herein, a method and apparatus are disclosed in one embodiment of the present invention as including the manufacture and use of a loop or apparatus having elastic properties. Here, the word “elastic” is used in the engineering sense. That is, elastic deflection or deformation is fully recoverable upon release of applied force or stress.
[0011] For example, a steel spring, certain types of polymeric materials, and the like may be stretched or compressed. Their stretch (elongation, strain) is proportional to the force or stress (weight, force, force per unit area) in an effectively linear relationship according to Hooke's Law. Hooke's Law states that force is equal to a constant characterizinag the material and its configuration, multiplied by the deflection. Of course, this is a linear relationship wherein deflection is proportional to force directly through the spring constant.
[0012] The apparatus may take on various configurations. For example, its cross section may vary from one sided (circular) to two sided (an elongate cross section terminating at each extremum at a comparatively zero distance), to three sided (triangular). Moreover, a four sided device (square, parallelogram, rhombus, rectangle, trapezoid, etc.), or the like is within contemplation. Moreover, five, six, eight, or some other number of sides may be considered.
[0013] The aspect ratio of thickness to width may vary. For example, a right circular cylinder may be one cross sectional representation of a segment of an apparatus. On the other hand, an oval cross section, a figure eight cross section, an ellipse, or the like may likewise be tractable. In fact, the cross sectional area and the cross sectional shape may be produced by extrusion, injection molding, or other process to be made in any number of shapes.
[0014] The band may also be extruded as a closed loop of any shape, and then sliced to form closed, narrow bands with their own cross sections representing the opening within the elastic apparatus.
[0015] The wall of such a band or apparatus may be of a thickness, length, and width to suit a user and supportable manufacturing processes. Also, the wall thickness will necessarily affect the stiffness or the spring constant governing performance of the apparatus. In some embodiments, the thickness may be comparatively smaller, with an inside diameter comparatively larger for the overall loop. Thus, the apparatus may stretch a greater or lesser distance. Material and dimensions may change how far it will stretch.
[0016] For example, a thicker wall will typically require more force to stretch the opening. A thinner wall will be easier to stretch. Likewise, the particular maximum deflection permissible in a specific elastomeric polymer may depend on its cross linking and its particular principal chemistry. Accordingly, some materials may stretch a mere ten to twenty percent of their initial circumference. Other materials may stretch literally one thousand percent of their initial circumference. Thus, maximum permissible deflection may be affected, as well as the stiffness or spring constant of the material itself or of a thicker or thinner cross section thereof.
[0017] This leads to the fact that a loop or apparatus in accordance with the invention may be used in a single pull and a single wrap around a pair of socks. In other embodiments, the loop may be sufficiently flexible, and have sufficient elongation that a loop may be placed around a pair of socks, twisted and then looped back over the pair again to provide two loops or two encircling of the pair of socks to bind them together.
[0018] Also, in certain embodiments, a tab or grip may be provided in one region of an apparatus. The loop, for example, may have a tab that extends radially outward. In other embodiments, the tab may actually extend axially upward or downward perpendicular to the plane representing the top and bottom surface of such a loop. In this way, fingers may obtain a good grip to place a loop on, or remove a loop from the socks.
[0019] The tab is perhaps more important after washing and drying of the socks. At this time, the socks may be fluffed up to their highest bulk. A tight constriction of the loop about the socks may render difficult placing a finger inside the loop or inside one turn of the loop in order to remove it from the socks. Thus, the tab provides a grip.
[0020] In certain embodiments, the grip is disposed in a particular shape, and may be provided in particular colors or shapes to indicate a logo, a message, a theme, a set, owner-selectable distinction, or the like. Likewise, words, such as instructions or other text, an image, or a logo may be built into the grip or tab used for handling, especially removal, of the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which:
[0022] FIG. 1 is a perspective view of one embodiment of an apparatus in accordance with the invention;
[0023] FIG. 2 is a cross-sectional view of various alternative cross sections of a loop apparatus in accordance with the invention;
[0024] FIG. 3 is a top plan view of the article of FIG. 1 ;
[0025] FIG. 4 is a front elevation view thereof, the rear elevation view being identical;
[0026] FIG. 5 is a right side elevation view thereof, which is identical to the left side elevation view thereof;
[0027] FIG. 6 is a top plan view of an alternative embodiment of a loop apparatus in accordance with the invention;
[0028] FIG. 7 is a front elevation view thereof, the rear elevation view being identical;
[0029] FIG. 8 is a right side elevation view thereof, the left side elevation view being identical thereto;
[0030] FIG. 9 is a perspective view thereof;
[0031] FIG. 10 is a prospective view of application of the apparatus in accordance with the invention, with the socks being absent for clarity;
[0032] FIG. 11 is a perspective view of an alternative embodiment of a loop apparatus in accordance with the invention;
[0033] FIG. 12 is a perspective view of various alternative embodiments for the tab of FIG. 11 ;
[0034] FIG. 13 a left side elevation view of an alternative embodiment of a loop apparatus in accordance with the invention, illustrating by exploded inset views, and various alternative cross sections;
[0035] FIG. 14 is a perspective view of one embodiment of a loop apparatus in accordance with the invention, being drawn around the pair of socks, twisted and drawn around the socks again to form a double loop or a double turn around the socks; and
[0036] FIG. 15 is a perspective view of a pair of socks in which a loop apparatus in accordance with the invention has been looped around a portion of the socks a single time to bind them together.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] It will be readily understood that the components of the present invention, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of various embodiments of the invention. The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
[0038] Referring to FIGS. 1 through 9 , while referring generally to FIGS. 1 through 15 , an apparatus 10 or loop 10 in accordance with the invention may be formed of a polymer, typically an elastomeric polymer having a suitable flexibility, spring constant, cross sectional area, and other dimensions to operate as an elastic band 10 . Typically, an apparatus 10 will be characterized by an outside diameter 12 or effective outside diameter 12 .
[0039] By effective diameter is meant the hydraulic diameter as understood in the engineering arts. A hydraulic diameter is four times the area enclosed divided by the wetted perimeter or the enclosed perimeter. Thus, a circle devolves to an actual physical diameter. An effective diameter or hydraulic diameter of a square is simply the length of one side.
[0040] Any other shape has a value of hydraulic diameter by the same relationship, which will be something calculated only because it may not actually exist anywhere. Slits and slots sometimes degenerate to simply the distance across the smaller dimension. Nevertheless, an effective diameter 12 may be calculated for any shape.
[0041] For example, the actual shape of the loop 10 or apparatus 10 may be any shape desired. For example, the shape of the outside diameter 12 is actually the outer surface 13 or defined by the outer surface 13 . Similarly, the inside diameter 14 , which is actually the effective internal diameter 14 , may be calculated according to the rules of hydraulic diameter. Likewise, the inner surface 15 describes or defines the actual perimeter giving rise to the effective inside diameter 14 . Accordingly, the thickness 16 need not be uniform. However, it has been found that a uniform thickness 16 is often the best to serve the need for a comparatively uniform deflection or strain.
[0042] Strain is actually a dimensionless deflection or stretch. By stretch is meant deflection in either direction, compression or tension. Thus, deflection is the general term, while stretch represents elongation under tensile load. Compression or shrinkage represents deflection under compressive load. The point here is that strain is a dimensionless number meaning the distance of deflection divided by the overall length dimension.
[0043] For example, a circle may have an amount of strain constituting a number of inches per inch of length of circumference or the number of centimeters per centimeter of overall length. Thus, it is proper to speak of deflection as distortion and change of dimension and strain as the normalized or nondimensionalized measurement of distance of strain per total distance.
[0044] Thus, for strain (normalized change of dimension) to be uniform about the entire circumference of an apparatus 10 , it is preferable that the thickness 16 as well as the top surface 17 a to bottom surface 17 b height 18 be uniform throughout. Even with a comparatively uniform thickness 16 , and a uniform height 18 , the circumference about the apparatus 10 may actually take on (be formed in) any shape.
[0045] Some examples are a star, a circle, a rectangle, an image shape, such as the head of a horse, the profile of an entire horse, the face of a cat, the entirety of a cat, the shape of a dog, the shape of any other animal pet, the shape of a particular vehicle style or design, and so forth. Thus, any of the conventional shapes of polygons, starts, circles, or images of live things or inanimate objects is a perspective profile to substitute for the “ring” 10 that is the apparatus 10 illustrated. One may thus consider the apparatus 10 to be defined by a wall 20 following any suitable shape and extending from an inner diameter 14 to an outer diameter 12 and having a height 18 .
[0046] As a practical matter, a method of manufacture may involve extruding the shape of the apparatus 10 . The extrusion constitutes the circumference thereof. Actually it includes both inner circumference and outer circumference. Generally, it is not necessarily a circular cross section. This may be done in a conventional extruder having a die shaped to the periphery or circumference, effectively, of the apparatus 10 . Extrusion may involve any of several suitable methods, but may benefit from a vertical extrusion of an elastomeric polymer.
[0047] Elastomeric polymers may include compositions of silicone, natural rubber, synthetic rubber, and substantially any elastomeric polymer. Silicone and other “high temperature” polymers are those having temperatures greater than would normally be melted by exposure to the hot air of a commercial or domestic clothes dryer. Silicone compositions are used in bakeware exposed to temperatures over 400 degrees Fahrenheit.
[0048] Thus, any such elastomeric material having the proper mechanical characteristics may serve. It requires a suitable spring constant, elongation, maximum stress at rupture, and so forth. Those properties are understood in engineering. Any material suitable and durable may serve as the elastomeric polymer from which the apparatus 10 may be formed.
[0049] Following extrusion, individual instances of the product 10 or apparatus 10 may be sliced or cut across the shape (cross section) at a periodicity equal to the height 18 . Thus, the height 18 may be adjusted to be comparatively shorter (thinner) or taller (thicker) as desired. There exist reasons to have the height 18 be comparatively low, even less than the wall thickness 16 in some instances. Total force required, ease of manipulation, and manufacturing are. In other instances it makes sense and provides a certain life expectancy and a different handling benefit of not “rolling up” to have the height 18 be comparatively longer than the wall thickness 16 , and sometimes several times larger (several multiples thereof). However such a loop 10 requires or admits to a single loop with no twisting or doubling up.
[0050] The shape of the apparatus 10 necessarily will have a cross section. Indeed, the cross section of the wall 20 itself, as well as the cross section of the gap 21 or space 21 in the center thereof may take on any suitable shape. The number of shapes possible is a digit too high to begin to consider even a small fraction of the possibilities. One may refer to FIG. 2 for the shapes of several polygons. These polygonal shapes may be the cross sections 22 of the wall 20 itself along the section A-A of FIG. 1 , as illustrated.
[0051] Nevertheless, each of these shapes of FIG. 2 also represents a possible shape for the interior surface 15 of the apparatus 10 . Thus, with the wall thickness minimized and represented only by a line, any of those shapes and more may represent the perimeter and outer of an apparatus 10 . Meanwhile, any of the other shapes of nature, plants, animals, houses, buildings, objects, tools, toys, vehicles, or the like may be the shape taken by the apparatus 10 when relaxed and unstretched.
[0052] A sheath 23 may be thought of as a decorative cover 23 . For example, an alternative mechanism for manufacturing an apparatus 10 in accordance with the invention may involve extrusion of the solid polymer in a cross section 22 illustrated. For example, a circular cross section 22 a , square cross section 22 b , triangular cross section 22 c , and trapezoidal cross section 22 d may represent the wall 20 of the apparatus 10 . Likewise, the rectangular cross section 22 e is a parallelogram 22 e . Meanwhile, the hexagon 22 f and octagon 22 g are not the limit. More sides are possible. Moreover, all of the shapes illustrated so far except a star are fully convex. They have no external concave surfaces. However, providing shapes of animals, plants, cars, other things, and so forth may involve the use of inside corners or concave corners on the outer perimeter of any of the walls 20 of an apparatus 10 .
[0053] Thus, virtually any cross section 22 may be molded or extruded. Extrusion provides a continuous process. Moreover, extruding a shape 22 or cross section 22 may be done as a linear and continuous process. To form an actual ring 10 , loop 10 , or the like as an apparatus 10 , one may bond cut ends of a stranded material to form the loop 10 . There will be some uneven stress across the cross section too, as a result. However, with a sufficiently soft elastomeric polymer, such a construction technique is totally tractable.
[0054] A sheath 23 is most easily applied to an open strand of a linear material having a cross section 22 . Thus, the decorative cover 23 may provide the entire decoration. In alternative embodiments, the decorative cover 23 may be augmented by having the ends thereof along with the ends of the internal wall 20 captured, bonded, cast, clipped, stapled, or otherwise captured in a grip or medallion that serves to close the loop 10 , as well as provide a material by which to grasp the apparatus 10 .
[0055] Referring to FIG. 10 , while continuing to refer generally to FIGS. 1 through 15 , an apparatus 10 may be used as a single loop 10 , or may be stretched and doubled back over itself. In the illustrated embodiment, the apparatus 10 may be placed around a pair of socks, drawn tight, and twisted as illustrated. The socks have been removed to illustrate the shape of the apparatus 10 . Nevertheless, in the center configuration of the apparatus 10 , stretching the apparatus 10 and twisting it to form two separate loops, serves to permit doubling up. Thus, ultimately, the apparatus 10 as in the configuration on the right demonstrates that the diameter has been diminished to about half. The overall stress or force has actually been doubled by two layers of the wall 20 . The cross-over 24 or twist 24 is necessary in order to form one complete loop 10 around the socks or the object to be tied. Another loop 10 is then stretched larger to fit over the same object in order to provide the double loop 10 illustrated as the consequence of such an operation.
[0056] It is worth noting that the thickness 16 and height 18 of the wall 20 cooperate along with the overall inside diameter 14 to determine the ease with which the apparatus 10 may be stretched about socks a first, second, or both number of times. The smaller the opening 21 or gap 21 enclosed by the wall 20 , the less space and therefore more constrictive hold will be imposed upon the grasped objects. The first loop 26 is typically made, and then all the slack or all the available tension drawn against it. Thereafter, a second loop 28 may follow the twist 24 , and enclose once again the same object.
[0057] The size, meaning here the thickness 16 , and height 18 , which are necessarily affected by the shape 22 or cross section 22 , will govern the stiffness or the resistance to stretching of the circumference or the diameters 12 , 14 of the loop apparatus 10 .
[0058] Referring to FIGS. 11 and 12 , while continuing to refer generally to FIGS. 1 through 15 , a tab 30 may act as a grip 30 for grasping and stretching the size of the apparatus 10 . For example, in applying the band 10 or apparatus 10 to an object or a bundle of objects to be gripped, one may insert fingers inside the space 21 encompassed by the wall 20 . However, following a laundering of the grasped objects, the loop 10 or apparatus 10 may be difficult to grasp.
[0059] Depending on how much tension was put in the wall 20 (where tension is a stress or force per unit cross sectional area), it may be quite unsatisfactory to reach a fingernail or finger underneath or inside the inner diameter 14 to pull against the inside surface 15 . Removing the apparatus 10 from a grasped bundle of articles may be done by rolling the apparatus 10 along the surface of the grasped objects.
[0060] It may be a more satisfactory mechanism to simply re-stretch one of the loops 26 , 28 by grasping the tab 30 , drawing it away from the grouped articles. Drawing enough slack may require moving it back and forth in a plane parallel to its upper and lower surfaces 17 a , 17 b . Once sufficient slack is drawn out of one of the loops 26 , 28 the other loop 28 , 26 may be drawn over the bundled articles. This effectively reduces multiple loops 26 , 28 to a single loop 10 .
[0061] In fact, depending on the particular dimensions it may be possible to loop more than just two loops 26 , 28 in the article 10 . Three, four, or more may be possible. Nevertheless, it has been found that one or two loops 26 , 28 will serve well and provide a sufficiently robust and long lived product 10 .
[0062] Referring to FIG. 12 , while continuing to refer generally to FIGS. 1 through 15 , the tab 30 may have any of a variety of shapes, and each may serve the purpose of decoration, information, or some other functionality. For example, the shape of the tab 30 may be somewhat arbitrarily defined. So long as it is of about sufficient surface area to be gripped well between the thumb and forefinger, it may serve its role to draw tension in the wall 20 of the apparatus 10 .
[0063] Some of the shapes illustrated are, for example, a simple semicircle or circle. Beginning at the top configuration and proceeding clockwise, a circle blended into the wall 20 may provide a tab 30 with an aperture in the middle, or simply a material of a different color. Similarly, proceeding clockwise a star or other recognizable shape or symbol may be used as the tab 30 . Meanwhile, an elongated or elliptical shape may provide space for a panel 32 receiving text 34 .
[0064] In each of the shapes of tabs 30 , the panel 32 serves as a frictional contact surface for the digits of a user. However, it may also serve the function of hosting text 34 . The shape may altered, such as the next (trapezoidal) shape. This may accommodate specific text or provide room for larger text farther from the wall 20 and smaller text closer thereto. Moving more of the material farther away from the wall 20 may provide less influence on the loop 10 by the change of cross sectional area in the tab 30 .
[0065] In other embodiments, the tab 30 may extend along a greater or lesser portion of the wall 20 . One will note that the trapezoidal shape is rounded at the corners. This may provide benefit in manufacturing. It may also provide reduction of stress concentrations at changes in cross section, such as between the tab 30 and the wall 20 . The rounded fillet area may provide additional life, and reduce the probability that such an interior corner might serve as a source of rupture for damage or failure over time.
[0066] Moving clockwise to the next inset, a shape of an object, such as the pair of socks shown in the same or different colors may be molded as the tab 30 . These may be extruded in different colors, or may be stamped in different shapes or with a boundary thus shown. As illustrated, this cross section may be altered to meet some other image desired for commercial identification, user classification, or a suggestion of use. Of course, different shapes, such as a rectangular tab 30 in the next inset, or a modified circular tab 30 may also be relied upon. Thus, the various tabs 30 a , 30 b , 30 c , 30 d , 30 e , 30 f , 30 g , are but a sampling of the possible shapes that may be formed. In fact, in FIG. 11 , a somewhat rounded corner on a rectangular object is but a variation of the somewhat elongated but circular shape of the tab 30 g . Thus, any of a variety of shapes that are suitable for gripping, may extend a sufficient distance away from the wall 20 to support a good stiff tug or pull to stretch the ring 10 open. Any may well serve as a decorative, functional, or both types of elements for the tabs 30 .
[0067] Referring to FIG. 13 , while continuing to refer generally to FIGS. 1 through 15 , the tab 30 need not be shaped in any particular way or limited to any particular shape in the orthogonal direction. That is, the top plan view illustrated in the tabs 30 a through 30 g may have a constant thickness, or it may vary.
[0068] For example, beginning clockwise at the top, a tab 30 may have a rectangular aspect or rectangular shape that is either thinner, thicker, or the same thickness as the height 18 of the wall 20 of the loop 10 . In fact, any of the shapes of FIG. 13 may actually have uniform thickness in the direction into the page. Alternatively, any of the shapes of FIG. 13 may also be applied to any of the shapes in FIG. 12 . Since each is a cross section in a direction orthogonal to the other, they may be used in any combination.
[0069] Thus, the profile of the tab 30 h is simply extending at exactly the same thickness 18 of the main loop 10 . The shape of the tab 30 j extends at a varying thickness, tapering as it extends away from the apparatus 10 . Similarly, the tab 30 k provides for an image 36 such as a logo 36 . Just as a surface parallel to the top surface 17 a of the loop 10 may have a message, a surface orthogonal thereto may have a logo 36 , text 34 , or other emblem.
[0070] Meanwhile, the dimensions of the tab 30 m illustrate that the panel 32 may include text 34 that is much smaller. Of course, a matter of design choice and utility of the tab 30 may be overridden by design characterizations or desires, communication of information, and so forth. Thus, in general, the shapes in a direction axially 11 a , radially 11 b or circumferentially 11 c may include all possibilities.
[0071] For example, an axis 11 d extending radially but orthogonal to both the axial direction 11 a , and another radial direction 11 b , may define a three-dimensional, rectangular set of coordinates. However, as a practical matter, in the illustrated embodiments, a circular cross section of the shape may be defined by an axial direction 11 a and a radial direction 11 b , which may proceed in any direction orthogonal to the axial direction 11 a , as will be sufficient to define a position. Nevertheless, in a circumferential direction 11 c , it will typically be necessary to define a point by at least three axes out of the group of axes 11 a , 11 b , 11 c , 11 d.
[0072] Referring to FIGS. 14 and 15 , while continuing to refer generally to FIGS. 1 through 15 , a pair of socks 40 may be grasped with multiple turns as illustrated in FIG. 14 , or as a single loop about a pair or multiple pairs. Typically, the thickness 16 , height 18 , and material are all matters of design choice and engineering of molds, dies, and the like. Likewise, an outer diameter 12 , inner diameter 14 , and the overall constitution of film in the polymer selected may all be matters of personal choice, design choice, or engineering expediency.
[0073] Thus, it may be possible to use two or more turns in an apparatus 10 about one or more pairs of socks 40 . Similarly, the single loop 10 may be sufficient. However, it has been found that more turns with higher tension become more difficult to remove as tension equalizes during the rustle and bustle of the washing and drying processes. Thus, an apparatus 10 is adaptable to being used on one pair of socks 40 with a single loop 10 , or providing multiple turns 26 , 28 with a single pair 40 .
[0074] The size of any of the dimensions may be selected to provide a comfort level. It may even be provided in multiple sets of dimensions in order to provide a tough pull or more forceful requirement, a more modest or medium amount of pull, or a comparatively easy pull. Of course these gradations may be color coded, may be marked, such as with numbers or emblems on the tab 30 , and so forth.
[0075] The present invention may be embodied in other specific forms without departing from its purposes, functions, structures, or operational characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | A sock tie is used when laundering socks, in order to keep a pair together. Formed of a comparatively high temperature polymer, the elastomeric loop may be drawn around a pair of socks one or more times to bind them together. The tension in the loop need not be excessively high. The nearer to the center of the length of a pair of socks the loop is placed, the less tension is required, inasmuch as the socks themselves by their random motion will resist self removal of the band or loop. Logos, labels, text, instructions, images, colors and the like may be formed into tabs attached at one or more points about the circumference of a sock tie loop. The tab provides an ease of removal while also providing space for advertising, logos, instructions, or the like. | 3 |
FIELD OF THE INVENTION
[0001] The invention relates to a capacitive sensing system and a capacitive sensing method.
BACKGROUND OF THE INVENTION
[0002] WO 2008/152588 A1 discloses a capacitive sensor for sensing electrical fields of a body comprising an electrode, a shield, an insulating separation material separating the electrode and the shield and a housing including associated electronic circuits, wherein the tribo-electric property of the insulating separation material or the material used for the housing substantially matches with that of the skin of the body thereby reducing the generation of static charge on the capacitive sensor. The capacitive sensor is used in applications where motions are present during measurement of electrophysiological signals from the body such as electrocardiography or electromyography.
SUMMARY OF THE INVENTION
[0003] Even if the generation of static charge on the capacitive sensor is reduced, the sensing signal of the capacitive sensor can still be distorted by the presence of static charges on the body which generally varies over time. Furthermore, the signal can be distorted by motion artifacts due to a varying distance between the object to be sensed and the capacitive sensor. The sensing signal is therefore a small low quality signal.
[0004] It is an object of the present invention to provide a capacitive sensing system and a capacitive sensing method, wherein the quality of a sensing signal generated by the capacitive sensing system is improved.
[0005] In an aspect of the present invention a capacitive sensing system for sensing an object is presented, wherein the capacitive sensing system comprises:
[0006] an electrical charge providing unit for providing a permanent electrical charge at a sensing site of the object,
[0007] a capacitive sensor comprising a sensing electrode for generating a sensing signal by capacitively sensing the object at the sensing site of the object.
[0008] Since the capacitive sensing system comprises an electrical charge providing unit for providing a permanent electrical charge at the sensing site of the object, fluctuations of electrical charge, in particular, of electrical static charge, can be reduced or eliminated, thereby reducing or eliminating a distortion of the sensing signal by these fluctuations, and, thus, improving the quality of the sensing signal generated by the capacitive sensing system. Moreover, by providing a permanent electrical charge at the sensing site of the object, the bias between the object and the sensing electrode of the capacitive sensor is intentionally preferentially made large, thereby increasing the sensitivity towards mechanical motions. The resulting sensing signal substantially caused by these mechanical motions between the object and the sensing electrode is generally larger than a signal generated substantially by an electrophysiological field like ECG or EMG. Thus, a larger signal having a larger signal-to-noise ratio and, therefore, having an improved quality is generated by the capacitive sensing system.
[0009] The electrical charge providing unit can be any unit being adapted for providing a permanent electrical charge at the sensing site of the object. Preferred embodiments of the electrical charge providing unit will be described further below.
[0010] The permanent electrical charge is preferentially a permanent electrical static charge. An electrical charge is preferentially regarded as being permanent, if the electrical charge is constant in time. A charge is preferentially regarded as being constant in time, if charge variations are smaller than 10%, further preferred smaller than 5% and even further preferred smaller than 3% for at least one minute, further preferred for at least one hour, further preferred for at least one day, further preferred for at least one month, and even further preferred for at least one year.
[0011] The capacitive sensing system is preferentially adapted for sensing a body of a person or of an animal, in particular, for generating a physiological signal of the body. The capacitive sensing system can be adapted for sensing the body through cloths, for example, if a person or an animal is located on a chair or in a bed. This allows, for example, monitoring health related parameters while a person is sleeping. The capacitive sensor is preferentially adapted for performing a contact less measurement of mechanical movements of a person or of an animal.
[0012] It is preferred that the electrical charge providing unit comprises an electret for being attached to the object for providing the electrical charge.
[0013] The electret is preferentially an electret foil. The electrical charge providing unit comprising an electret is an embodiment of the electrical charge providing unit which ensures a reliable and constant over time electrical static charge at the sensing site.
[0014] The electret, which is preferentially an electret foil, is preferentially adapted to be attached to a body of a person or of an animal or to other objects that are preferentially mechanically coupled to the body like cloths, chair, bed et cetera.
[0015] The electret is a permanently charged material which means that no external biasing is needed and the charge will not disappear over time.
[0016] The electret can be adapted to be put on a part of the object, which is preferentially a body, that has to be sensed. The size of the electret, in particular, of the electret foil, can be adapted to the size of the region, which is intended to be sensed, for example, if only a small muscle group has to be sensed, the electret can have a smaller size, and if, for example, the upper chest has to be sensed for probing respiration, the size of the electret can be larger. The electret, in particular, the electret foil, can be adapted to be used as a disposable foil.
[0017] It is further preferred that the electrical charge providing unit comprises a voltage source and an electrically conducting element for being attached to the object, wherein the voltage source is connected to the electrically conducting element for providing the permanent electrical charge.
[0018] The voltage source is, for example, a battery of several volts, for example, a battery having less than ten volts.
[0019] The conducting element is preferentially a conductive foil. Also this conductive foil can be adapted to the size of a region, which is intended to be sensed. Also the conductive foil can be adapted to be used as a disposable foil.
[0020] The conductive foil is preferentially made of a bio compatible material. The conductive foil is preferentially adapted to be suitable for being worn longer periods of time, for example, for being worn minutes to days. The conductive foil is preferentially thin, i.e. has preferentially a thickness smaller than 1 mm, in order to be as unobtrusive as possible. The conductive foil can be made of a conductive textile.
[0021] A permanent amount of electrical static charge is provided at the sensing site. Therefore, a movement of the sensing site with respect to the sensing electrode, i.e. a movement of the permanent amount of electrical static charge with respect to the sensing electrode, yields a modification of the capacitance of the capacitor formed by the sensing electrode and the object and, thus, a change of the sensing signal, which is mainly caused by this relative movement and not by fluctuating static charges on the object. Thus, by detecting changes of the sensing signal distance variations between the object and the sensing electrode can be determined.
[0022] It is preferred that the capacitive sensing system further comprises a property determination unit for determining a property of the object from the generated sensing signal.
[0023] Variations of the sensing signal can be related to a movement caused by heart activity, respiration, mechanical activity of muscles and other mechanical vibrations appearing from the object, if the object is a body of a person or of an animal. Also other kinds of movements of the object, in particular, of the body, can be determined from the generated sensing signal. Thus, the property determination unit is preferentially adapted to determine, for example, the heart rate or respiration from the generated sensing signal. However, also other property related to a movement of the object can be determined from the generated sensing signal.
[0024] If the variations of the sensing signal relate to mechanical vibrations caused by different effects like heart activity and respiration, these effects can be separated by using frequency filtering techniques for filtering the part of the sensing signal that corresponds to the respective effect.
[0025] In a further aspect of the invention a capacitive sensing method for sensing an object is presented, wherein the capacitive sensing method comprises the steps of:
[0026] providing a permanent electrical charge at a sensing site of the object by an electrical charge providing unit,
[0027] generating a sensing signal by capacitively sensing the object at the sensing site of the object by a sensing electrode of a capacitive sensor.
[0028] In a further aspect of the present invention a computer program for sensing an object is presented, wherein the computer program comprises program code means for causing a capacitive sensing apparatus as defined in claim 4 to carry out following steps:
[0029] generating a sensing signal by capacitively sensing the object at a sensing site of the object, at which a permanent electrical charge is provided by an electrical charge providing unit, by a sensing electrode of a capacitive sensor,
[0030] determining a property of the object from the generated sensing signal by a property determination unit,
[0000] when the computer program is run on a computer controlling the capacitive sensing apparatus.
[0031] It shall be understood that the capacitive sensing system of claim 1 , the capacitive sensing method of claim 5 and the computer program of claim 6 have similar and/or identical preferred embodiments as defined in the dependent claims.
[0032] It shall be understood that a preferred embodiment of the invention can also be any combination of the dependent claims with the respective independent claim.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following drawings:
[0034] FIG. 1 shows schematically and exemplarily a capacitive sensing system for sensing an object,
[0035] FIG. 2 shows schematically and exemplarily a further capacitive sensing system for sensing an object,
[0036] FIG. 3 shows schematically and exemplarily in more detail a circuit of a capacitive sensing system,
[0037] FIG. 4 shows schematically and exemplarily a sensing signal generated by a capacitive sensing system, and
[0038] FIG. 5 shows exemplarily a flowchart illustrating a capacitive sensing method for sensing an object.
DETAILED DESCRIPTION OF EMBODIMENTS
[0039] FIG. 1 shows schematically and exemplarily an embodiment of a capacitive sensing system for sensing an object. The capacitive sensing system 1 comprises a capacitive sensor 2 and an electrical charge providing unit 4 . The capacitive sensor 2 includes a sensing electrode 5 for generating a sensing signal by capacitively sensing the object 3 at a sensing site 6 of the object 3 . The electrical charge providing unit 4 is adapted to provide a permanent electrical charge at the sensing site 6 of the object 3 .
[0040] The capacitive sensing system 1 is adapted for sensing a body of a person or of an animal for determining a physiological property of the body 3 . The capacitive sensing system 1 is adapted for sensing the body 3 through cloth, for example, if a person or an animal is located on a chair or in a bed. This allows, for example, monitoring health related parameters while the person is sleeping.
[0041] In the embodiment shown in FIG. 1 , the electrical charge providing unit 4 is an electret foil. The electret foil 4 is adapted to be attached to a body 3 of a person or of an animal or to other objects that are preferentially coupled to the body like cloth, chair, bed et cetera. The electret foil 4 at the sensing site 6 ensures a reliable and constant over time electrical static charge at the sensing site 6 .
[0042] The electret foil comprises an attachment means for being attached to the body 3 or to the other objects exemplarily mentioned above that are preferentially mechanical coupled to the body. The attachment means is, for example, an adhesive means, a strapping means or it can be any other means for attaching the electret foil to the body or to the above mentioned other objects that are preferentially coupled to the body.
[0043] The electret foil 4 is a permanently charged material which means that no external biasing is needed and the charge will not disappear over time.
[0044] The size of the electret foil 4 is adapted to the size of the region, which is intended to be sensed, for example, if only a small muscle group has to be sensed, the electret foil 4 can have a smaller size, and if, for example, the upper chest has to be sensed for probing respiration, the size of the electret foil 4 can be larger.
[0045] The capacitive sensor 2 comprises the electrode 5 and electronics 7 which will be exemplarily described further below with reference to FIG. 3 .
[0046] Since a permanent amount of electrical static charge is provided by the electret foil 4 at the sensing site 6 , a movement of the sensing site 6 with respect to the sensing electrode 5 , i.e. a movement of the permanent amount of electrical static charge with respect to the sensing electrode 5 , yields a modification of the capacitance of the capacitor formed by the sensing electrode 5 and the object 3 with the electret foil 4 and, thus, a change of the sensing signal, which is mainly caused by this relative movement.
[0047] The capacitive sensing system 1 further comprises a property determination unit 12 for determining a property of the object 3 from the generated sensing signal, in particularly, from variations of the generated sensing signal.
[0048] In this embodiment, the electret foil 4 is coupled to the body 3 at the chest of the person. A movement of the chest of the body 3 is substantially caused by respiration and heart activity. The property determination unit 12 is preferentially adapted to separate variations of the sensing signal caused by heart activity and variations of the sensing signal caused by respiration by using frequency filtering techniques. For example, for retrieving variations of the sensing signal caused by heart activity a frequency filter filtering frequencies between 1 Hz and 30 Hz can be used, and for retrieving variations of the sensing signal caused by respiration frequency filtering techniques can be used which filter frequencies between 0.1 Hz and 1 Hz.
[0049] In an embodiment, the property determination unit is adapted to determine the temporal positions of the heart beats and to determine from these temporal positions the heart rate. Alternatively or in addition, the property determination unit can be adapted to determine the respiration rate from the variations of the generated sensing signal, which is preferentially filtered. The temporal positions of the heart beat can, for example, be determined by detecting the temporal positions of the second regions 24 showing large variations of the sensing signal, which are exemplarily shown in FIG. 4 and which will be explained in more detail further below. The respiration rate can, for example, be determined as the frequency of a fundamental oscillation of the sensing signal.
[0050] In other embodiments, in addition or alternatively, the property determination unit can be adapted for determining another property of the object from the variations of the sensing signal. For example, the property determination unit can be adapted to determine the mechanical activity of muscles and other mechanical vibrations appearing from the object. The property determination unit can also be adapted to determine other kinds of movements of the object, in particular, a movement of the entire object or of an arm, a leg or the head can be determined from the variations of the sensing signal.
[0051] FIG. 2 shows schematically and exemplarily a further embodiment of a capacitive sensing system. The capacitive sensing system 11 shown in FIG. 2 also comprises a capacitive sensor 2 and an electrical charge providing unit. The capacitive sensor 2 comprises a sensing electrode 5 for generating a sensing signal by capacitively sensing the object 3 at a sensing site 6 of the object. The electrical charge providing unit comprises a voltage source 8 and an electrically conducting element 9 for being attached to the object 3 , wherein the voltage source 8 is connected to the electrically conducting element 9 for providing a permanent electrical static charge. In this embodiment, the electrically conducting element 9 is a conductive foil. Also this conductive foil 9 is adapted to the size of the region of the object, which is intended to be sensed. In an embodiment, the voltage source 8 is a high voltage generator. In an alternative embodiment, the capacitive sensor, i.e. the probing circuit, is brought to a potential being larger than the potential of the object, which is preferentially grounded. Also in this way a permanent electrical charge can be provided at the sensing site of the object, wherein a large permanent bias is provided for generating an amplified sensing signal being indicative of motions between the sensing electrode and the object.
[0052] FIG. 3 shows schematically and exemplarily an embodiment of the capacitive sensing system, wherein a possible electronic circuit is shown in more detail.
[0053] FIG. 3 shows schematically and exemplarily on the left side the body 3 including a source of a bioelectric signal V bio being, for example, an ECG signal. At a reference site 6 , which is, for example, a chest of the body 3 , a permanent electrical charge is provided by an electret foil 4 . The body 3 is capacitively coupled to a power grid 13 with a capacitance C bp and to earth 16 with a capacitance C be .
[0054] On the right side of FIG. 3 a circuit 7 of the capacitive sensor 2 is schematically and exemplarily shown. The capacitive sensor 2 comprises an electrode 5 that is capacitively coupled to the body 3 over a distance d, a bias resistor R i and a buffer amplifier 22 with its input capacitance C 1 . Preferentially, the input capacitance C i is eliminated using a neutralization technique like the neutralization technique described in WO 2005/018041 A2. The capacitive sensor 2 provides an output signal OUT being the sensing signal generated by the capacitive sensor 2 . The circuit reference Com is capacitively coupled to earth 20 with capacitance C ce so that the body 3 is also capacitively coupled to the circuit reference via C be and C ce .
[0055] A sensing signal generated by the capacitive sensor 2 is schematically and exemplarily shown in FIG. 4 . FIG. 4 shows the amplitude A in volts V depending on time t in seconds s. In a first region 23 variations of the sensing signal indicate the ECG signal. The following second region 24 shows much larger variations of the sensing signal caused by movements of the electret foil 4 relative to the electrode 5 . Thus, the electret foil 4 yields a strong amplification of the sensing signal. Based on these variations of the sensing signal in the second region 24 , the property determination unit 12 can determine a property of the object 3 .
[0056] The electrical charge providing unit, i.e., for example, the electret foil 4 or the voltage source 8 connected with the electrically conducting element 9 , which provide a permanent electrical charge, provides a DC bias between the body 3 and the electrode 5 and amplifies thereby the sensing signal indicative of mechanical motions of the body, i.e. indicative of distance variations between the body and the electrode.
[0057] It should be noted that in FIG. 4 it is assumed that the person has held his breath, i.e. respiration movements are neglected in FIG. 4 . However, in other embodiments variations of the sensing signal can also be caused by respiration or by other effects. The property determination unit is preferentially adapted to use a frequency filter for filtering the desired effect out of the generated sensing signal and/or the determined distance variations.
[0058] The capacitive sensing system can be used for remote sensing of vital body signs like heartbeat, respiration, et cetera. The capacitive sensing system preferentially allows unobtrusively, in particular, through closing, sensing of heartbeat and/or respiration. At least parts of the capacitive sensing system, in particular, the capacitive sensor, is thereby integrated into a bed or a car. The bed is an ideal place for monitoring health related parameters, because sleeping is part of our daily routine. Moreover, a bed is a place where people rest an average of eight hours a day with environmental and physiological conditions that are quite stable, signals therefore can be generated with less motion artifacts.
[0059] FIG. 5 shows a flowchart exemplarily illustrating an embodiment of a capacitive sensing method for sensing the object 3 .
[0060] In step 101 , a permanent electrical charge is provided at the sensing site 6 of the object 3 by the electrical charge providing unit, i.e., for example, by attaching the electret foil 4 or the electrically conducting element 9 which is electrically connected to the voltage source 8 to the body 3 .
[0061] In step 102 , a sensing signal is generated by capacitively sensing the object 3 at the sensing site 6 by the sensing electrode 5 of the capacitive sensor 2 .
[0062] In step 103 , the property determination unit 12 determines a property of the object 3 from the generated sensing signal.
[0063] In other embodiments, step 103 can be omitted, wherein the capacitive sensing method generates a sensing signal indicative of distance variations between the object and the electrode and, thus, indicative of a movement of the object.
[0064] If the voltage source 8 is used together with the conductive foil 9 for providing a permanent electrical static charge on the body 3 , the voltage source 8 is preferentially adapted such that a maximum voltage is not exceeded, wherein the maximum voltage is chosen such that the person to which the conductive foil is to be attached, is not adversely affected.
[0065] Although in the above described embodiments an electret foil and a voltage source in combination with an electrically conducting foil have been described as an electrical charge providing unit, in other embodiments, other means for providing a permanent electrical charge can be used.
[0066] Although in the above described embodiments the permanent electrical static charge is provided on the body of a person for generating a sensing signal indicative of a movement of the chest of the person, in other embodiments movements of other parts of the body of the person or of the entire body of the person can be determined. Furthermore, movements of parts of a body or a the entire body of an animal can be determined. Also movements of other objects like technical objects can be determined by using the capacitive sensing system.
[0067] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
[0068] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.
[0069] A single unit or device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
[0070] Determinations like the determination of distance variations or the determination of a property of the object performed by the distance variations determination unit and the property determination unit can be performed by any other number of units or devices, for example, by a single unit only or by more than two units. The determination of the property of the object from the generated sensing signal and/or the control of the capacitive sensing system in accordance with the capacitive sensing method can be implemented as program code means of a computer program and/or as dedicated hardware.
[0071] A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium, supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.
[0072] Any reference signs in the claims should not be construed as limiting the scope. | The invention relates to capacitive sensing system ( 1 ) for sensing an object. The capacitive sensing system ( 1 ) comprises an electrical charge providing unit ( 4 ) like an electret foil for providing a permanent electrical charge at a sensing site ( 6 ) of the object ( 3 ) and a capacitive sensor ( 2 ) comprising a sensing electrode ( 5 ) for generating a sensing signal by capacitively sensing the object ( 3 ) at the sensing site ( 6 ) of the object ( 3 ). By providing a permanent electrical charge at the sensing site ( 6 ) of the object ( 3 ), the bias between the object ( 3 ) and the sensing electrode ( 5 ) of the capacitive sensor ( 2 ) is intentionally preferentially made large, thereby increasing the sensitivity towards mechanical motions. The resulting sensing signal substantially caused by these mechanical motions between the object ( 3 ) and the sensing electrode ( 5 ) is generally larger than a signal generated substantially by an electrophysiological field. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a chemical mechanical polish apparatus that is used for manufacturing semiconductor devices. In particular, the present invention relates to a polish adjustment of a polish pad using a dresser.
[0003] 2. Description of Related Art
[0004] [0004]FIG. 9 shows drawings for explaining the prior art. It shows a state in which a polish pad 102 is pad-dressed. As shown in FIG. 9A, a dresser 103 is placed on a polish pad 102 that is adhered onto a surface plate 101 . When a pressure is applied to the dresser 103 , the surface of the polish pad 102 is ground by a diamond particle surface 103 A formed on the peripheral surface zone of the dresser 103 . As a result, the surface of the polish pad 102 is polished as shown in FIG. 9A. In general, an abrasive material or pure water is supplied to the polish pad during a dressing process.
[0005] A polish is carried out in a planarization process in manufacturing a semiconductor device or the like. During such a polish, however, the abrasive material and/or polish dust stick to the surface of the polish pad 102 , which eventually causes the polish process to become unstable. For this reason, in order to maintain a stable polish, the polish pad 102 needs to be dressed and polished by the dresser 103 .
[0006] However, the above-described prior art has the following problem. As shown in FIGS. 9B and 9C, the grind amount of the portion of the polish pad 102 at distance Rt from the center of rotation of the surface plate 101 is proportional to the contact length L of the diamond particle surface 103 A with the polish pad 102 at distance Rt from the center of the surface plate 101 . By a simple calculation, the length L is given by
L= 2· Rt ·(Cos −1 (( Rt 2 +Rx 2 −R 1 2 )/(2 ·Rt·Rx ))−Cos −1 (( Rt 2 +Rx 2 −R 2 2 )/(2 ·Rt·Rx )) (1)
[0007] Here, as shown in FIGS. 9B and 9C,
[0008] Rx: the distance between the center of the dresser 103 and the center of the surface plate 101
[0009] R 1 : the outside radius of the diamond particle surface 103 A
[0010] R 2 : the inside radius of the diamond particle surface 103 A.
[0011] [0011]FIG. 11 shows the dependency of the contact length L of the diamond particle surface 103 A with the surface of the polish pad 102 at distance Rt from the center of the surface plate 101 when, for example, Rx=17 cm, R 1 =16 cm, and R 2 =15.5 cm. The graph shows that the length L varies over a wide range within the polish pad. Since the grind amount of the polish pad 102 is proportional to the length L, the grind amount of the polish pad 102 varies over a wide range. As a result, the surface of the polish pad 102 cannot be made flat as needed. The minimum grind amount required to achieve a satisfactory state of polish is pre-determined. Therefore, even at a location where the value of L is the smallest, the required minimum grind amount must be secured. On the other hand, at a location where the value of L is large, the polish pad is over-ground.
[0012] As discussed above, the value of L grows very large in a region near the periphery of the surface plate (at points 29 cm from the center of the surface plate) and in a region near the center of the surface plate (at points 1.5 cm from the center of the surface plate). Therefore, in these regions, the polish pad is ground by a large amount. The problem that the polish pad is ground by a large amount in a region near the periphery of the surface plate can be solved by increasing the diameter of the dresser 103 . FIG. 12 shows the dependency of L on the distance Rt from the center of the surface plate 101 in the case the diameter of the dresser 103 has been increased to Rx=20 cm, R 1 =19 cm, and R 2 =18.5 cm. In this case, as seen from FIG. 12, the value of L is 1.47 cm at the point where Rt=29 cm, which is shorter by 2.1 cm than the value of L at the point where Rt=29 cm in the case shown in FIG. 11. However, in the interior of the admissible range, the value of L achieves a maximum of 2.44 cm at the point where Rt=1.5 cm, which is not significantly smaller than the maximum value of L achieved at Rt=1.5 cm in the case shown in FIG. 11, resulting in practically no improvement at all.
[0013] Thus, in the case the grind amount of the polish pad varies over a wide range depending on the distance Rt from the center of the surface plate 101 , the life span of the polish pad is seriously shortened. A polish pad is dressed and ground after it has been used to polish a prescribed number of semiconductor wafers. FIG. 10 is a schematic cross sectional view of the grind surface 102 A of the polish pad 102 attached onto the polish surface plate 101 . In FIG. 10, the region 102 A 1 where the grind amount is the largest (position 1.5 cm from the center of the surface plate), the region 102 A 2 where the grind amount is the smallest (position 6.9 cm from the center of the surface plate), and the region 102 A 3 which is the outer limit of the admissible polish range (position 29.0 cm from the center of the surface plate) are indicated with arrows.
[0014] As mentioned before, in order to carry out a stable polish, the polish pad must be ground at least by a minimum necessary amount. The region 102 A 2 , where the grind amount is the smallest (position 1.5 cm from the center of the surface plate), must also be ground at least by the same minimum necessary amount, which is 0.67 μm per wafer in this case. However, in the region 102 A 1 , where the grind amount is the largest (position 1.5 cm from the center of the surface plate), 1.67 μm per wafer is ground. The life span of the polish pad 102 is determined by the amount ground by the dressing. Therefore, if the polish pad 102 is dressed by an excessive amount, even the surface of the polish surface plate 101 can be ground. When this happens, the surface of the polish surface plate 101 is damaged, and the polish surface plate 101 needs to be replaced.
SUMMARY OF THE INVENTION
[0015] As explained above, the polish pad 102 is ground by a large amount in the interior of the admissible polish range even though the other part of the polish pad 102 remains sufficiently thick within the admissible polish range. Therefore, the polish pad 102 , which is relatively expensive among the required members for manufacturing semiconductors, needs to be replaced at an early stage. This means that the semiconductor manufacturing cost is significantly increased. Moreover, it normally takes 1 to 1.5 hours to replace a polish pad, during which the CMP apparatus cannot manufacture any semiconductor, resulting in a low operation rate. As the life span of the polish pad 102 becomes shorter, the polish pad 102 must be replaced more frequently, which leads to a low operation rate of the apparatus.
[0016] The present invention aims to solve the above-described problems. Therefore, it is an object of the present invention to provide a polish apparatus having a dresser equipped with a polish pad and an inclined polish particle surface for adjusting the polish. It is also an object of the present invention to provide a polish apparatus having a dresser equipped with a polish pad and a polish particle surface for adjusting the polish such that a pressure for adjusting a polish can be applied onto the polish particle surface. This object is achieved by combinations described in the independent claims. The dependent claims define further advantageous and exemplary combinations of the present invention.
[0017] This summary of the invention does not necessarily describe all necessary features of the present invention. The present invention may also be a sub-combination of the above-described features. The above and other features and advantages of the present invention will become more apparent from the following description of embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 shows a top view and a cross sectional view of a dresser ring according to the first embodiment of the present invention.
[0019] [0019]FIG. 2 shows the relation between the press-down pressure of the dresser ring and the grind rate of the polish pad according to the first embodiment of the present invention.
[0020] [0020]FIG. 3 shows the relation between the pressure of the polish pad and the amount of displacement of the polish pad according to the first embodiment of the present invention.
[0021] [0021]FIG. 4 shows a cross sectional view of a polish apparatus for measuring the displacement amount of the polish pad according to the first embodiment of the present invention.
[0022] [0022]FIG. 5 shows a top view of the polish pad according to the first embodiment of the present invention.
[0023] [0023]FIG. 6 shows a graph of the relation between the distance from the center of the surface plate 1 and the grind rate of the polish pad according to the first embodiment of the present invention.
[0024] [0024]FIG. 7 shows a cross sectional view of a dresser ring according to the second embodiment of the present invention.
[0025] [0025]FIG. 8 shows a graph of the relation between the distance from the center of the polish surface plate 1 and the grind rate of the polish pad according to the second embodiment of the present invention.
[0026] [0026]FIG. 9 shows a top view and a cross sectional view of a dresser ring according to the prior art.
[0027] [0027]FIG. 10 shows a cross sectional view of the polish pad during a polish according to the prior art.
[0028] [0028]FIG. 11 shows a graph of the relation between the distance from the center of the polish surface plate 101 and the contact length of the diamond particle surface with the polish pad according to the prior art.
[0029] [0029]FIG. 12 shows a graph of the relation between the distance from the center of the polish surface plate 101 and the contact length of the diamond particle surface with the polish pad in the case the diameter of the dresser is large according to the prior art.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention will now be described based on preferred embodiments, which do not intend to limit the scope of the present invention, but exemplify the invention. Not all of the features and the combinations thereof described in the embodiment are necessarily essential to the invention.
[0031] [0031]FIG. 1 shows the first embodiment of the present invention. FIG. 1A shows a cross sectional view of a dresser ring 3 . The dresser ring 3 shown in FIG. 1A is installed on a polish surface plate 101 as in the prior art, and a dressing process is carried out. FIG. 1B shows the cross section across the line A-A′ of-the dresser ring 3 shown in FIG. 1A. FIG. 1C shows a magnified view of what is shown in FIG. 1B. In the first embodiment of the invention, as shown in FIG. 1B and FIG. 1C, the surface of the diamond particle surface 3 A of the dresser ring 3 A is inclined with respect to the surface of the polish pad 102 . Because of this inclination, when the dresser ring 3 is pressed onto the polish pad 102 at a constant pressure, the displacement amount of the polish pad 102 varies across the points between 3 A 1 and 3 A 2 . As a result, the press-down pressure varies across the points between 3 A 1 and 3 A 2 .
[0032] As a consequence, each point on the polish pad 102 is ground by the dressing action at a different rate. In other words, the controlled grind rate is distributed in the radial direction of the diameter of the dresser ring 103 . In the present embodiment, the above-described inclination was prescribed by determining the value of D shown in FIG. 1C so that the grind rate of the polish pad 102 at outside diameter point 3 A 2 in the radial direction will be 5 times as large as the grind rate of the polish pad 102 at inside diameter point 3 A 1 . More specifically, using a dresser ring 103 identical to the one used in the prior art shown in FIG. 9, the relation between the press-down pressure of the dresser ring 103 applied onto the polish pad 102 and the grind rate with respect to the press-down pressure is obtained. If the relation between the pressure and the grind rate obtained in this way has turned out to be, for example, the one shown in FIG. 2, the desired grind rate ratio of 5 to 1 is obtained. As a result, the pressures P 1 and P 2 can be obtained.
[0033] Next, the relation between the press-down pressure applied onto the polish pad 102 and the displacement amount of the polish pad 102 is obtained. If the relation between the press-down pressure applied onto the polish pad 102 and the displacement amount of the polish pad 102 is, for example, as the one shown in FIG. 3, the displacement amounts D 1 and D 2 of the polish pad 102 caused by the pressures P 1 and P 2 , respectively, are obtained. In this case, the value of the afore-mentioned quantity D is determined by the equation D=D 1 −D 2 . Here, the relation between the press-down pressure applied onto the polish pad 102 and the displacement amount of the polish pad 102 is obtained as follows. In FIG. 4, which shows a cross sectional view of a polish apparatus for measuring the displacement amount of a polish pad, a first load 4 and a second load 5 are placed on a polish pad 2 . The displacement amount d of the polish pad 2 in this case is obtained by measuring the displacement of the position f of the surface of the first load 4 . The position f is easily measured by a laser displacement gauge 6 . Similarly, by changing the weight of the second load 5 , the relation between the pressure and the polish pad displacement amount d is obtained a shown in FIG. 3.
[0034] The dresser ring 3 , which has been formed using the value of D obtained in the above-described manner, is pressed onto the polish pad 2 with the press-down pressure P 0 =(P 1 +P 2 )/ 2 , and a dressing process is carried out. As a result, the dresser ring 3 is pressed onto the polish pad 2 with the pressures of P 1 and P 2 at positions 3 A 1 and 3 A 2 of FIG. 1C, respectively. In this case, the polish pad grind rate at 3 A 2 becomes 5 times as large as that at 3 A 1 . The grind rate obtained in the prior art depends solely on the contact length L of the polish pad with the dresser. In contrast, according to the present embodiment, the press-down pressures at distinct contact points differ from each other. Therefore, the grind rate of the polish pad 2 in the dressing process according to the present embodiment depends not only on the contact length L of the polish pad with the dresser but also on the press-down pressure at each contact point.
[0035] More specifically, in FIG. 5 which shows a top view of the polish pad 2 , the polish pad grind rate at points that are at distance Rt from the center of the polish surface plate 1 is obtained by integrating the function
K(r)·Rt (2)
[0036] from θ2 (the value of angle θ at which the circle of radius Rt centered the center of the polish surface plate 1 intersects the inner boundary circle of radius R 2 of the dresser ring 3 ) to θ1 (the value of angle θ at which the circle of radius Rt centered the center of the polish surface plate 1 intersects the outer boundary circle of radius R 1 of the dresser ring 3 ). Here, by a geometric analysis of the drawing on FIG. 5, K(r) is given by
K ( r ) k ·(( r −R 2 )·4/(R 1 −R 2 )+1), k constant. (3)
[0037] Since r is a function of angle θ, K(r) is expressed as a function of θ as follows.
K ( r )= K (θ)= k ·((( Rt ·cos θ− Rx ) 2 +Rt 2 ·sin 2 θ) 0.5 −R 2 )· 4/(R 1 −R 2 )+1) (4)
[0038] The grind rate V(Rt) of the polish pad at points that are at distance Rt from the center of the surface plate is given by
∫ θ2 θ1 k ·((( Rt −cos θ− Rx) 2 +Rt 2 ·sin 2 θ) 0.5 −R 2 )·4/(R 1 −R 2 )+1)· Rt·dθ. (5)
[0039] Here,
[0040] Rx: the distance between the center of the dresser 3 and the center of the polish surface plate 1 ;
[0041] R 1 : the radius of the outer boundary circle of the dresser ring 3 ; and
[0042] R 2 : the radius of the inner boundary circle of the dresser ring 3 .
[0043] [0043]FIG. 6 shows a graph which expresses the relation between the grind rate V(Rt) and the distance Rt from the center of the polish surface plate 1 in the case Rx=20 cm, R 1 =19 cm, and R 2 =18.5 cm. In FIG. 6, for ease of comparison with the prior art, the constant k is prescribed so the minimum of the grind rate according to this embodiment is achieved at the same point at which the minimum of the grind rate is achieved in the prior art. As shown in FIG. 6, the grind rate according to the prior art is 2.44 (relative value) at the point where the grind rate of the polish pad 2 is the maximum in the interior of the admissible polish range. On the other hand, the grind rate according to the present embodiment is 2.03 (relative value). Thus, according to the present embodiment, the grind rate can be controlled. As a result, the polish pad cost is reduced and the operation rate of the CMP apparatus is improved.
[0044] Next, a cross sectional view of a dresser ring according to the second embodiment of the-present invention is shown in FIG. 7. As in the case of the first embodiment, FIG. 7 shows a cross sectional view of the dresser ring 3 across the line A-A′. As shown in FIG. 7, according to the second embodiment of the present invention, the diamond particle surface of the dresser ring and its support part are divided into five parts 3 B 1 , 3 B 2 , 3 B 3 , 3 B 4 , and 3 B 5 . Further, distinct pressures P 1 , P 2 , P 3 , P 4 , and P 5 are applied to 3 B 1 , 3 B 2 , 3 B 3 , 3 B 4 , and 3 B 5 , respectively. The values of these pressures are determined as follows. Using the graph shown in FIG. 2, the value of P 2 is determined so that the grind rate at 3 B 2 will be 74% of the grind rate at 3 B 1 . Similarly, the values of P 3 , P 4 , and P 5 are determined so that the grind rates at 3 B 3 , 3 B 4 , and 3 B 5 will be 48%, 39%, and 30% of the grind rate at 3 B 1 , respectively. In this way, the dresser ring is divided into five parts and pressures of distinct values are applied to the five parts so that the grind rates at these parts are sequentially inclined. Therefore, the grind rate of the polish pad V(Rt) (relative value) at points that are distance Rt from the center of the polish surface plate is given by the following equation (6).
V (Rt) = k·RL ·(Cos −1 (Rt+Rx 2 − R 11 2 ) /(2·Rt·Rx))−Cos 31 1 (Rt 2 −Rx 2 − R 21 2 )/( 2·Rt·Rx)))− 0.74· k Rt·(Cos 31 1 (Rt 2 −Rx 2 − R 12 2 )/( 2·Rt·Rx)) −Cos −1 Rt 2 +Rx 2 − R 22 2 )/(2·Rt·Rx))) +0.48· k· Rt·(Cos −1 (Rt 2 +Rx 2 −R13 2 )/(2·Rt·Rx))−Cos −1 (Rt 2 +Rx 2 − R 23 2 )/(2· RL ·Rx)))+0.39· k· Rt·(Cos −1(Rt 2 +Rx 2 − R 14 2 )/(2·Rt·Rx))−Cos 31 1 (Rt 2 +Rx 2− R 24 2 )/( 2·Rt·Rx)))+ 0.30· k· Rt·(Cos −1(Rt 2 +Rx 2− R 15 2 )/(2·Rt·Rx))−Cos− 1 (Rt 2 +Rx 2 − R 25 2 )/(2·Rt·Rx))) (6)
[0045] Here the inner and outer diameters of the dresser ring are the same as in the prior art, and
[0046] R 11 : the outer radius of 3 B 1 =19.0 cm, R 21 : the inner radius of 3 B 1 =18.91 cm;
[0047] R 12 : the outer radius of 3 B 2 =18.89 cm, R 22 : the inner radius of 3 B 2 =18.81 cm;
[0048] R 13 : the outer radius of 3 B 3 =18.79 cm, R 23 : the inner radius of 3 B 3 =18.71 cm;
[0049] R 14 : the outer radius of 3 B 4 =18.69 cm, R 24 : the inner radius of 3 B 4 =18.61 cm; and
[0050] R 15 : the outer radius of 3 B 5 =18.59 cm, R 25 : the inner radius of 3 B 4 =18.50 cm.
[0051] Using these values, Equation (6) is evaluated. FIG. 8 shows the result of this calculation. For ease of comparison with the prior art, the minimum grind rate according to this embodiment is set equal to the minimum grind rate obtained in the prior art.
[0052] As seen from the graph shown in FIG. 8, which shows the relation between the distance from the center of the polish surface plate 1 and the grind rate of the polish pad, in the interior of the admissible polish range, the maximum polish rate is 2.03 according to the present embodiment. This value is substantially equal to the maximum polish rate obtained in the first embodiment. This value is significantly better than the maximum polish rate obtained in the prior art, which is 2.44 (relative value). Therefore, according to the second embodiment also, the same polish pad cost reduction effect and the same degree of operation rate improvement of the CMP apparatus are achieved.
[0053] According to the present invention, the pressure applied onto the polish pad 102 by the dresser 103 used in the prior art is varied linearly with a nonzero slope in the radial direction of the diameter of the dresser 103 . Therefore, the maximum grind amount of the polish pad within the admissible polish range is reduced. As a result, the life span of the polish pad 102 with respect to the number of semiconductor wafers to be polished is increased, the cost required for the polish pad to polish one semiconductor wafer is reduced, and the operation rate of the CMP apparatus is improved.
[0054] Further, according to the present invention, the diamond particle surface of the dresser is inclined, and the pressure applied to the polish surface of the dresser is varied linearly with a nonzero slope. Therefore, the polish amount of the polish pad can be controlled to a uniform value. As a result, the length of the replacement period of a polish pad is increased, and the operation rate of the CMP apparatus is significantly improved.
[0055] Although the present invention has been described by way of exemplary embodiments, it should be understood that many changes and substitutions may be made by those skilled in the art without departing from the spirit and the scope of the present invention which is defined only by the appended claims. | The polish particle surface of the dresser of a chemical mechanical polish apparatus used for a planarization process in manufacturing semiconductor devices is inclined. Moreover, the pressure to be applied onto the polish surface of the dresser is linearly varied with a nonzero slope. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a massager of the roller type adapted to massage back and/or hips of a user sitting down or upright on a chair or lying on a mat by rollers incorporated in the chair of mat so as to roll on the back and/or the hips, respectively, exerting appropriate pressure thereupon.
2. Description of the Prior Art
A massager of the roller type is well known which contains within back and/or seat of a chair or within a mat rollers so as to massage the back and/or the hips of a user.
However, with the massager of the prior art, the rollers are reciprocated in a single direction and a substantially limited area is massaged in a fixed direction. Consequently,it has been found that the affected part of user's body is often left insufficiently massaged.
SUMMARY OF THE INVENTION
It is a principal object of the invention to provide a traveling massage unit wherein a pair of massage pressure rollers are transported on a traveling housing which transports thereon the massage pressure rollers and encloses and mounts thereon drive and operating mechanisms for incorporation as a unit into the seat or backrest of a chair or a mat. A single variable speed reversible electric motor and the mechanisms transported in the housing provide for a multiplicity of modes of directional travel of the massage unit and modes of operation of the massage pressure rollers.
Provision is made for the mount of the massage pressure rollers to mount them coaxially spaced in a common plane above the top of the housing and being selectively driven alternatively in circular and clockwise motion while the traveling housing is stationary along a rectilinear path of travel or traveling in either of opposite directions.
The pair of massage pressure rollers extend away from each other transversely of the rectilinear path of travel for massaging in a large area and the rollers are movable reciprocably between two planes spaced above the top of the housing for applying a variable massage pressure in the massage area thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view exemplarily illustrating the massager of the invention;
FIG. 2 is a sectional front view of this massager;
FIG. 3 is a sectional side view of the massager with a first solenoid 22 deenergized;
FIG. 4 is a view similar to FIG. 3 but with the first solenoid 22 energized;
FIG. 5 is a sectional front view illustrating, in an enlarged scale, a mechanism for up-and-down motion of rollers 7;
FIG. 6 is a plan view illustrating, as partially broken away, the massager with a third solenoid 64 deenergized; and
FIG. 7 is a view similar to FIG. 6 but with a third solenoid 64 energized;
FIG. 8 is a perspective view illustrating a state in which a second gear 82 is engaged with a gear 43; and
FIG. 9 is a perspective view illustrating a state in which the first gear 79 is engaged with a gear 43.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention will be more readily understood from the following detailed description of a specific embodiment in reference with the accompanying drawings.
Referring to FIG. 1, reference numeral 1 designates a basic traveling massage unit comprising a box or housing 2, travelling gears 3 carried by the box 2 on both sides thereof adapted to be engaged with associated rail-like racks 4 so that the box 2 reciprocates on the racks 4 as the travelling gears 3 are rotated in alternate directions and stopped at a desired position as the travelling gears 3 are controllably stopped, elongate massage pressure rollers 7 rotatably supported by respective arms 6 laterally extending from opposite sides of a support 5 which is, in turn, supported on a top of the box 2 at a center thereof so that the rollers 7 simultaneously present up-and-down motion and one-directional circular motion as the support 5 is put in the same motions. With such basic massaging mechanism 1 incorporated in chair or mat so that the rollers 7 may bear against the back and/or the hips of user, the rollers 7 roll on the back and/or the hips as they describe a circle in one direction while moving up and down and thereby massage the above-mentioned regions of the user's body.
Referring to FIG. 2 illustrating the invention in a sectional front view, the box 2 contains therein a speed variable reversible motor 8 having an output shaft 9 to which a fist pulley 10 as well as a second pulley 11 are fixed and a belt 14 is disposed about the first pulley 10 and a pulley 13 fixed to a first shaft 12 extending across the interior of the box 2.
Referring to FIGS. 3 and 4 illustrating the invention in a sectional side view, there is provided around the first shaft 12 at the right side thereof as viewed in FIGS. 3 and 4 a first worm gear 15 formed with a clutch claw 18, which is supported by a bearing 17 of a support 16 so as to be rotatable relative to the first shaft 12. Opposed to the left end of the first worm gear 15, a clutch 20 having a claw 21 is mounted by a key 19 on the first shaft 12 so as to be axially slidable but not rotatable relative to the first shaft 12.
Above the first worm gear 15, the ceiling of the box 2 carries a first solenoid 22 having a plunger 23 normally thrusted out leftward under biasing effect of a spring 24 and the plunger 23 is provided at an end with an arm 25 of inverted U-shape straddling the first worm gear 15 as well as the clutch 20. When the first solenoid 22 is deenergized, the right end of the arm 25 urges a brake disc 26 under the biasing effect of the spring 24 to brake the first worm gear 15 and the clutch 20 is held under a combined biasing effect of a soft spring 27 and a hard spring 28 to be spaced from the first worm gear 15, as will be seen in FIG. 3.
A worm wheel 29 engaged with the first worm gear 15 having an axle 30 fixedly extending through the center thereof, said axle 30 further extending outward from the opposite side walls of the box 2 and the respective travelling gears 3 are fixed by keys 31 on the opposite ends of the axle 30.
When the first solenoid 22 is energized during rotation of the reversible motor 8, the plunger 23 retracts and the arm 25 moves rightward as will be seen in FIG. 4. The clutch 20 slides on the key 19 under the biasing effect of the hard spring 28 as the brake disc 26 is spaced from the first worm gear 15, so that the claw 21 is engaged with the clutch claw 18 to rotate the first worm gear 15, thus the travelling gears 3 rotate together with the worm wheel 29 engaged with the first worm gear 15 and travel on the respective racks 4.
A manual switch (not shown) or a limit switch provided at each end of the course of travel may be operated and thereby the direction of rotation of the reversible motor 8 may be reversed to switch the direction of travel and a revolving speed of the reversible motor 8 may be controllably varied to adjust the speed of travel.
As the first solenoid 22 is deenergized, it restores the position shown by FIG. 3 at which the claw 21 of the clutch 20 is disengaged from the clutch claw 18 and the brake disc 26 is urged against the first worm gear 15 to brake it and thereby to brake the travelling gears 3.
Similarly, there is provided around the first shaft 12 at the left side thereof as viewed in FIGS. 3 and 4 a second worm gear 32 formed with a clutch claw 18, which is supported by a bearing 17 of a support 16 so as to be rotatable relative to the first shaft 12. Opposed to the right end of the second worm gear 32, a clutch 20 having a claw 21 is mounted by a key 19 on the first shaft 12 so as to be axially slidable but not rotatable relative to the first shaft 12.
Above the second worm shaft 32, the ceiling of the box 2 carries a second solenoid 33 having a plunger 23 normally thrust out rightward under biasing effect of a spring 24 and the plunger 23 is provided at an end with an arm of inverted U-shape straddling the second worm gear 32 as well as the clutch 20. When the second solenoid 33 is deenergized, the left end of the arm 25 urges a brake disc 26 under biasing effect of the spring 24 to brake the second worm gear 32, the clutch 20 is held under a combined biasing effect of a soft spring 27 and a hard spring 28 to be spaced from the second worm gear 32 and a roller 36 rotatably supported by the forward end of the plunger 23 is received in a notch formed in a disc 37 which is fixed on a second shaft 34 extending across the interior of the box 2.
A worm wheel 38 is engaged with the second worm gear 32, and a gear 39 coaxially fixed to the worm wheel 38 is engaged with a gear 40 which is, in turn, engaged with a gear 41 fixedly mounted on the second shaft 34. Opposite ends of this second shaft 34 extend outward through the box 2 carry thereon eccentric gears 42, respectively.
As shown in an enlarged scale by FIG. 5, a gear 43 centrally provided with a spline shaft 44 disposed integrally thereon is rotatably supported on the top of the box 2 and the support 5 has female splines 45 adapted to be engaged over the spline shaft 44 so that the support 5 may be slidably moved up and down. The support 5 is formed around its outer periphery with a flange 46. There is provided a supporting arm 48 centrally formed with an opening 47 for loosely receiving the support 5 and having a pair of pressure plates 49 fixed on its top surface for loosely holding the flange 46. To prevent the supporting arm 48 from oscillating, a holder plate 50 is inserted into a guide hole 51 formed in the top wall of the box 2.
Pinions 51 are rotatably mounted on opposite ends of the arm 48, respectively, so as to be engaged with the respective eccentric gears 42 and tension springs 52 are suspended between the respective ends of the arm 48 and the associated ends of the second shaft 34 in order to bias the pinions 51 to be in engagement with the respective eccentric gears 42.
When the second solenoid 33 is energized during rotation of the reversible motor 8, the plunger 23 and therefore the roller 36 retract away from the notch 35 of the disc 37, the arm 25 moves leftward, the brake disc 26 is disengaged from the second worm gear 32, the clutch 20 slides along the key 19 under biasing effect of the hard spring 28 so as to engage the claw 21 with the clutch claw 18. The frequency in rotation of the second worm gear 32, and rotation of the worm wheel 38 being engaged with the second worm gear 32 causes the gears 39, 40 and 41 to rotate the eccentric gears 42 around the second shaft 34, as best seen in FIG. 4.
Thereupon, engagement between the eccentric gears 42 and the pinions 51 causes the arm 48 to be moved up and down together with the support 5 and causes also the rollers 7 to be moved up and down.
Up-and-down motion of the rollers 7 is terminated as follows: Deenergization of the second solenoid 33 causes the plunger 23 to be advanced first until the roller 36 rolls on the periphery of the disc 37 and then further advanced until the roller 36 is received in the notch 35, whereupon the arm 25 moves rightward until the clutch 20 is let out. Consequently, the brake disc 26 brakes the second worm gear 32 and thereby terminates up-and-down motion of the rollers 7.
At this moment, the rollers 7 are necessarily located at their lowermost positions at which the rollers 7 can easily move, since the roller 36 has been received in the notch 35 of the disc 37.
The Frequency at which the rollers 7 move up and down can be varied by adjusting the revolving speed of the reversible motor 8.
On the top of the box 2, a third shaft 53 is rotatably supported by bearings 54 and a belt 56 is disposed about a pulley 55 mounted in an axially slidable but not rotatable manner by a key 57 on and relative to the third shaft 53 and the second pulley 11 fixed to the output shaft 9 of the reversible motor 8.
A third worm gear 58 formed on its right end with a clutch claw 59 is supported by the bearings 54 in axially slidable and rotatable manner on and relative to the third shaft 53 and a clutch 61 is slidably mounted by a key 60 on this third shaft 53 so that the clutch 61 is held to be spaced from the third worm gear 58 under a combined biasing effect of the hard spring 28 suspended between the clutch 61 and a first ring 62 and the soft spring 27 suspended between the clutch 61 and the third worm gear 58.
A second ring 63 is fixed on the third shaft 53 on the left side of the middle one of the bearings 54.
A third solenoid 64 is provided on the top of the box 2 and a forward end of an arm 66 connected to a plunger 65 associated with the third solenoid 64 extend rightward slightly beyond the second ring 63. A brake disc 67 is welded to the forward end surface of the arm 66.
The plunger 65 is biased by a combined effect of a compression spring 68 and a tension spring 69 to be thrusted out and a roller 70 rollably supported on the forward end of the plunger 65 is opposed to an annular wall 71 provided on the top of the gear 43. The annular wall 71 is formed with a notch 72.
A worm wheel 73 is engaged with the third worm gear 58 and a belt 77 is draped about a pulley 74 coaxially fixed to the worm wheel 73 and a pulley 78 coaxially fixed to a first gear 79 which is in engagement with a second gear 82.
As shown by FIGS. 8 and 9, the first gear 79 comprises upper full-circumferential gear section 80 and lower semicircumferential gear section 81. Similarly, the second gear 82 comprises upper full-circumferential gear section 83 and lower semicircumferential gear section 84. The full-circumferential gear sections 80, 83 of the first and second gears 79, 82 are normally in mutual engagement and the first and second gears 79, 82 are adapted to be rotated in mutually opposite directions.
Both the first gear 79 and the second gear 82 are dimensioned to be half in their sizes with respect to the gear 43. As shown by FIGS. 7 and 9, the semicircumferential gear section 84 of the second gear 82 is out of engagement with the gear 43 when the semicircumferential gear section 81 of the first gear 79 is in engagement with the gear 43 and, as shown by FIGS. 6 and 8, the semicircumferential gear section 81 of the first gear 79 is out of engagement with the gear 43 when the semicircumferential gear section 84 of the second gear 82 is in engagement with the gear 43.
Accordingly, the semicircumferential gear section 81 of the first gear 79 comes in engagement with the gear 43 which is then rotated by 90° clockwise as viewed in FIG. 7 as the worm wheel 73 is rotated in the direction as indicated by an arrow in FIG. 7. Thereupon, the semicircumferential gear section 81 of the first gear 79 is disengaged from the gear 43 and now the semicircumferential gear section 84 of the second gear 82 comes in engagement with the gear 43, as shown by FIG. 8, and the gear 43 is rotated by 90° counterclockwise as viewed in FIG. 7. In this manner, the gear 43 repeatedly rotates in alternate directions.
When the third solenoid 64 is energized during rotation of the reversible motor 8, the arm 66 moves leftward together with the plunger 65 and the third shaft 53 also moves leftward, as best seen in FIG. 7, whereupon the brake disc 67 is disengaged from the third worm gear 58, simultaneously the clutch 61 is biased leftward by the hard spring 28 to be engaged with the clutch claw 59 of the third worm gear 58 and the third worm gear 58 is rotated together with the third shaft 53. This rotation is transmitted by the worm wheel 73, the pulley 74, the belt 77, the pulley 78 and the first gear 79 or the second gear 82 to the gear 43 which, in turn, rotates by 90° in alternate directions. In operative association with the gear 43, the spline shaft 44 also rotates by 90° in alternate directions together with the support 5 having the female splines 45 in engagement therewith. The support 5 swings with the flange 46 loosely held between the supporting arm 48 and the pressure plates 49 and the pressure rollers 7 more around the support 5 by 90° in alternate directions.
When the third solenoid 64 is deenergized, the plunger 65 is advanced first until the roller 70 rolls on the annular wall 71 and then until the roller 70 is received in the notch 72, whereupon the plunger 65 is further advanced so as to move the third shaft 53 rightward, as best seen in FIG. 6. The clutch 61 is disengaged from the third worm gear 58 as the brake disc 67 bears against the third worm gear 58, and rotation of the third worm gear 58 and therefore the circular motion of the rollers 7 is terminated.
Now a common axis of the rollers 7 is orthogonal to the direction in which the box 2 travels since the roller 70 is in engagement with the notch 72 of the annular wall 71. Namely, the rollers 7 roll on the surface to be massaged with their common axis being orthogonal to the direction in which the box 2 travels.
As will be apparent from the foregoing description, this embodiment is so arranged that the first solenoid 22, the second solenoid 33 and the third solenoid 64 may be selectively energized or deenergized to obtain rectilinear reciprocating motion, up-and-down motion and circular motion of the rollers required to massage the affected part, separately or in operative association with one another.
It should be understood that the rollers 7 are preferably made of suitable magnetic material to facilitate blood circulation in the affected part. | A driven massager of roller type for incorporation into a seat or backrest of a chair or into a mat as traveling massage unit. A traveling housing of the massage unit houses and carries drive and operating mechanisms for driving the traveling unit and operating a rotatable pair of elongate massage pressure rollers carried thereon disposed axially spaced in a common plane above the housing and driven alternatively in circular clockwise and counterclockwise motion while the traveling housing is stationary along a rectilinear path of travel or traveling thereon in two opposite directions on a pair of parallel gear racks laterally spaced defining the path of travel. The traveling housing is provided with driven paired gears on opposite sides for traveling on the gear racks. The massage pressure rollers are mounted on a support that provides for moving the rollers between two planes spaced above the level of the traveling housing for variably applying massage pressure to a user seated in the chair or reclining thereon or on a mat. The various circular motions and movements between the planes can be effected simultaneously or separately with the massage unit stationary or traveling. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority pursuant to 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/225,888, filed Aug. 17, 2000, which application is specifically incorporated herein, in its entirety, by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method and apparatus for improving bandwidth efficiency in a computer network. More specifically, this invention pertains to a bandwidth management tool that implements a set of rules for directing network traffic according to current network bandwidth levels.
[0004] 2. Description of Related Art
[0005] Bandwidth is a critical resource and a key cost for Internet service providers (ISPs) in particular. Reliable bandwidth usage auditing and monitoring is important in two types of Web hostings offered by ISPs, i.e., “co-location” and “dedicated/shared-services. The Internet is a collection of interconnected (public and/or private) networks linked together by a set of standard protocols (such as TCP/IP and HTTP) to form a global, distributed network. As used herein, “Internet” is intended to refer to what is now commonly known as the Internet, it is also intended to encompass variations which may be made in the future, including changes and additions to existing standard protocols.
[0006] Bandwidth refers to maximum available bit rate for a specific application. In the context of a communication link of a computer network, bandwidth refers the maximum information rate that may be transmitted through the link. As used herein, the bandwidth capacity of a communication link includes any limitations such as arise from characteristics of servers, routers, and other network devices along a link.
[0007] Overuse of available bandwidth is generally undesirable. Although certain latency is inherently associated with any computer network (latency refers to the delay experienced by a packet from the source to destination), when bandwidth usage of a communication link approaches or saturates the bandwidth (capacity) of a communication link, increased latency and/or transmission failure results. Therefore, it is desirable to operate a computer network so as to preserve a margin of excess bandwidth at all times.
[0008] Bandwidth is also a commodity that may be assigned a definite economic value. In co-location services, a customer owns a dedicated Web server located at an Internet Service Provider's (ISP's) facility, and purchases Internet bandwidth from the ISP. The ISP buys bandwidth in bulk and resells it to each customer. Bandwidth is typically purchased in blocks. For example, a company may pay a fixed amount for a block of one hundred megabits of bandwidth. When bandwidth usage exceeds this amount, the company either incurs surcharges (in the event that it has acquired the ability to “burst” over the paid amount) or hits a cap, and is unable to serve all of the content that has been requested of it. The former results in undesired extra charges, with the latter results portions of the content being indiscriminately not served.
[0009] In dedicated-server service, customers rent dedicated servers that are owned and maintained by the ISP. In shared-server service, customers rent disk space, and share CPU and ETHERNET bandwidth with other website customers on the ISP's equipment. While this provides a low cost service for the customer, it frequently results in an overcrowding of the equipment and long delays or inaccessibility of the sites sharing the server. When the ISP has a clear picture of usage patterns, users can be relocated onto servers that do not clash with other users, or changed to dedicated-server service.
[0010] Accordingly, customers and ISP's alike desire accurate auditing, monitoring, and allocation of the bandwidth usage by each Web hosting customer. Current software tools for these tasks are not optimal.
[0011] The Web hosting business is becoming increasingly competitive. Customers are demanding guaranteed serviced and accountability for the access bandwidth charges by their ISPs. The customers too desire to monitor their own usage patterns in real time. It is further desirable to provide a guaranteed quality of service to improve customer satisfaction. In addition, unlike hit-rate data provided by other software, bandwidth usage patterns give web site owners a different way for gauging responses to changes in content on their sites.
[0012] A prior art pure-software approach to bandwidth management implements a priority-based queuing algorithm completely in UNIX or WINDOWS. These implementations usually have too much operating system overhead and throughput rarely exceeds 1,000 Kb/s. A prior art pure hardware approach implements a control algorithm in logic. But only very simple algorithms are practical, such as packet counting and dropping when a bandwidth limit is reached. These basic approaches can drop too many packets unnecessarily, which results in massive re-transmission on the Internet. Instead of improving throughput, these algorithms may actually degrade the network. A further disadvantages of hardware methods is that new features, e.g., Internet Protocol versions upgrades, generally require replacement of hardware equipment.
[0013] Routers are commonly used in the art and typically implement the use of headers and a forwarding table to determine the path in which data packets are sent. Very little filtering of data is done through routers. In fact, most routers do not distinguish between the different types of data being transmitted. Nevertheless, bandwidth management strategies are typically implemented at the router level. In networks where files of various types and sizes are frequently passed, however, these strategies are often inefficient.
[0014] Accordingly, it would be desirable to provide a method and apparatus for monitoring and optimizing bandwidth usage.
SUMMARY OF THE INVENTION
[0015] The present invention provides a system and method for operating a server to improve bandwidth efficiency in a computer network, that overcomes the limitations of the prior art. The server is operable to transmit files between a memory of the server and destinations on the computer network through a communication link having a finite bandwidth. The files are distinguishable by type and the server is provided with a rule set for prioritizing transmission of files by type. The method comprises monitoring a bandwidth usage of the communication link, and triggering application of the rule set when the bandwidth usage exceeds a threshold amount. The threshold amount is determined relative to the finite bandwidth. The method further comprises distinguishing between the files according to type, and prioritizing transmission of the files according to type and according to the rule set.
[0016] Bandwidth conditions of a given link may vary under different environmental conditions. In practice, synchronous, interactive, and real-time applications, which are bandwidth-sensitive, can require minimum bandwidth guarantees, and can require sustained and burst-scale bit rates. On the other hand, network administrators may want to limit bandwidth taken by non-productive traffic. Even though bandwidth may be allocated for specified applications, it does not mean that these applications are necessarily using that bandwidth. Therefore, the invention provides for enforcing bandwidth restrictions and rules for allocating bandwidth differently, depending on transient network conditions.
[0017] A rule set will herein be defined to be a set of techniques or mechanisms including policies that can be applied in a network to manage limited network resources such as bandwidth and the like. These techniques are intended to improve overall network performance and efficiency. They are also intended to provide for more predictability and orderliness in the event of network congestion. The techniques should also isolate faults and provide visibility into performance problems. Additionally, they should meet the diverse user and application requirements as per an organization's business goals. Furthermore, rule sets are intended to increase the “goodput” traffic, i.e., economically desirable traffic, and prevent the abuse of network resources.
[0018] The invention further provides various methods for distinguishing between files and thus enables classification of any given file by file type. The rule set is then applied to control the rate of transmission of the file, or whether to allow transmission of a file at all, depending on its file type and on other parameters such as the bandwidth usage and network conditions. The file type may be determined when a file is requested for transfer, or by a disk (memory) crawling agent at periodic intervals. Furthermore, a group of file servers, such as in a server farm, may be instructed to operate according to the same rule set. Modified rule sets or portions thereof may periodically be broadcast to servers in the farm from a master server.
[0019] When a predetermined bandwidth threshold is reached on a communication link, a rule set for reducing bandwidth demand may be applied by the server. The rule set preferably provides different rules for application under different conditions. For example, if bandwidth is being used at 80% of capacity, a first rule may be applied. If bandwidth usage increases to 90%, a second rule may be applied, that reduces network demand more than the first rule. In general, the rule set operates to restrict demand by restricting access to bandwidth according to file priority.
[0020] A more complete understanding of a method and apparatus for improving bandwidth efficiency in a computer network will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings which will first be described briefly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a block diagram demonstrating a preferred embodiment of the invention; and
[0022] [0022]FIG. 2 is a flow chart outlining the operation of a bandwidth management system according to a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The present invention is directed towards a method and apparatus for improving bandwidth efficiency in a computer network. Combining servers and processing power into a single entity has been relatively common for many years in research and academic institutions. In the detailed description that follows, like element numerals are used to describe like elements illustrated in one or more figures.
[0024] A rule set will herein be defined to be a set of techniques or mechanisms including policies that can be applied in a network to manage limited network resources such as bandwidth and the like. These techniques are intended to improve overall network performance and efficiency. They are also intended to provide for more predictability and orderliness in the event of network congestion. The techniques should also isolate faults and provide visibility into performance problems. Additionally, they should meet the diverse user and application requirements as per an organization's business goals. Furthermore, rule sets are intended to improve bandwidth efficiency based on the economic value of network resources.
[0025] Preferred embodiments of the present invention operate in accordance with a plurality of networked computers, such as, for example, a user computer and a server computer which are coupled together on a communications network, such as the Internet or a wide area network. FIG. 1 depicts a block diagram demonstrating a preferred embodiment of the invention. As illustrated, an ISP computer system 10 is shown to communicate with a plurality of user computer systems 30 via the Internet 20 . It should be appreciated that user computers 30 may include any type of computing device that allows a user to interactively browse websites, such as a personal computer (PC) that includes a Web browser application 32 (e.g., Microsoft Internet ExplorerTM or Netscape Communicator™). Suitable user computers 30 equipped with browsers 32 are available in many configurations, including handheld devices (e.g., PalmPilot™), personal computers (PC), laptop computers, workstations, television set-top devices, multi-functional cellular phones, and so forth.
[0026] In a preferred embodiment of the invention, ISP computer system 10 further comprises a bandwidth management tool 12 coupled to a router unit 14 and to a Web server farm 16 connected to an HTML documents database 17 . Router unit 14 may comprise a plurality of routers connecting any number of computers in a network. The type of routers used in a preferred embodiment can be of any standard type as known in the art.
[0027] Web server farms such as Web server farm 16 are generally known in the art and are typically comprised of a plurality of Web servers. In practice, a Web server farm typically refers to an ISP that provides Web hosting services using multiple servers. More specifically, a server farm is a group of networked Web servers that are housed in one location. In a preferred embodiment, Web server farm 16 streamlines internal processes by distributing the workload between the individual components of the farm and expedites computing processes by harnessing the power of its multiple servers. Web server farms such as Web server farm 16 typically rely on load-balancing software that accomplishes such tasks as tracking demand for processing power from different machines, prioritizing the tasks and scheduling and rescheduling them depending on priority and demand that users put on the network. When one server in the farm fails, another server may be used as a backup.
[0028] As is also generally known in the art, Web servers such as those in Web farm 16 access a plurality of Web pages, distributable applications, and other electronic files containing information of various types stored in HTML document databases 17 . As a result, Web pages may be viewed on various user computers 30 ; for example, a particular Web page or other electronic file may be viewed through a suitable application program residing on a user computer 30 , such as a browser 32 , or by a distributable application provided to the user computer 30 by a Web server. It should be appreciated that many different user computers, many different Web servers, and many different search servers of various types may be communicating with each other at the same time.
[0029] It should be further appreciated that a user identifies a Web page that is desired to be viewed at the user computer 30 by communicating an HTTP (Hyper-Text Transport Protocol) request from the browser application 32 . The HTTP request includes the Uniform Resource Locator (URL) of the desired Web page, which may correspond to an HTML document stored in the HTML documents databases 17 . The HTTP request is routed to the Web servers via the Internet 20 . The Web servers then retrieve the HTML document identified by the URL, and communicate the HTML document across the Internet 20 to the browser application 32 . The HTML document may be communicated in the form of plural message packets as defined by standard protocols, such as the Transport Control Protocol/Internet Protocol (TCP/IP).
[0030] In a preferred embodiment of the invention, a software agent is created and stored within the bandwidth management tool 12 in order to monitor bandwidth usage in a computer network. More specifically, a network manager creates a general set of formulas that can be used to create rules applicable at different bandwidth levels either constantly or at appropriate intervals. For example, the rule for “mp3” files might be: full speed until 90% of bandwidth is achieved; then between 90% and 95%, slow service to a maximum of 1 kbps multiplied by the current bandwidth percentage minus 90 , then above 95%, slow service to a maximum of 0.5 kbps multiplied by the current bandwidth percentage minus 90 . So, there is a master rule set that is created which can be used by the software agent to generate the specified rule set in light of the then-current bandwidth level.
[0031] For further example, the rule set may be as follows:
[0032] Maintain below 95% of the 100 megabit cap by invoking as many of the rules (in order) as are necessary:
[0033] 1. Block service of any files of non-standard types;
[0034] 2. Block service of any “.zip” files;
[0035] 3. Cap the speed by which portions of any file exceeding 500 k are served;
[0036] 4. Block service of any file larger than 1 megabyte;
[0037] 5. Block service of any files from the “fundownloads” directory.
[0038] In addition, the rule set may include formulaic rules, such as “reduce the maximum file size that may be served by 50 k every minute until a bandwidth threshold is no longer exceeded.”
[0039] So long as the bandwidth usage remains below a specified cap, no limitations are placed on file types or sizes available for download. Once bandwidth usage passes a specified amount (e.g., 95% of the cap, or 95 megabits out of a 100 megabit pipe), the software agent issues commands (either via a network connection, altering the contents of a shared file, or otherwise) that change the behavior of the web server to limit bandwidth based on a specified rule set. The rule set may limit the download speed of specified files (potentially based upon file size), may limit the file types that may be downloaded, the sites that may be downloaded from, may limit the file sizes that may be downloaded, or may otherwise change the behavior of the web servers based upon overall enterprise bandwidth use. In the above description, it should be appreciated that such rules may also apply to file uploads.
[0040] In a preferred embodiment, a software agent obtains a list of all file names and their corresponding file sizes in order to determine which files match specific rule-set criteria. The software then manipulates the file names to determine whether they are in fact likely to be parts of a single, larger file. As a first step, the software agent may delete all numbers from selected file names. Any files that are identically named after the elimination of all numbers would then be marked as potentially restrictive and their names and aggregate size would be reported. Of course, this can be limited to numbers in conjunction with specified letters (such as r00, r41, etc., as the “r” denotation often indicates file compression and division via the RAR method). Similarly, this can be limited to specified file types or files other than specified types (for example, graphics files such as *.jpg are often sequentially numbered and may be a good candidate for exclusion).
[0041] [0041]FIG. 2 shows a flow chart outlining exemplary operation of a bandwidth management tool 12 according to an embodiment of the invention. This procedure begins at step 100 with a query being made of all routers within router unit 14 . Individual results from this query are then compiled by the bandwidth management tool 12 in order to calculate the total network bandwidth at step 105 . A comparison is then made at step 110 between the master rule set and the calculated network bandwidth. Depending on how much network bandwidth is being used, the bandwidth management tool 12 then continues at step 115 by determining whether a particular rule-driven action should be made. If an action is indeed required at step 115 , then the bandwidth management tool 12 next determines which specific rule corresponds to the current bandwidth conditions of the network at step 120 ; otherwise, the procedure repeats itself by simply returning to step 100 where the bandwidth management tool 12 again queries router unit 14 . Once a specific rule is selected at step 120 , the selected rule is then broadcast to all appropriate Web servers within Web server farm 16 at step 125 and then executed accordingly at step 130 . The bandwidth management tool 12 then repeats this procedure by returning to step 100 where another router unit 14 query is made.
[0042] It should be appreciated that alternative embodiments of the invention may be implemented in which the described master rule set is programmed into each Web server in Web server farm 16 instead of a centralized location (i.e., the bandwidth management tool). In such embodiments, however, it should be further appreciated that router unit 14 queries, such as those described in step 100 of the flow chart in FIG. 2, must be made by each server in Web server farm 16 .
[0043] Various methods may be used for classifying files for purposes of prioritization. Files may be classifies at the time a file is requested for transmittal to or from the server. In the alternative, software may “crawl” through the file storage memory of a web server to classify files found there. For example a disk crawling agent may seek to identify files that are grouped according to a file naming or directory naming scheme that would permit aggregation of the group files into a single file. Such files are likely to be illicit or undesirable. For example, the software may crawl through the directory structure and obtains a list of all file names and the corresponding file sizes. The software then manipulates the file names to determine whether they are in fact likely to be parts of a single, larger file. Similarly, file crawling may be used to identify specified file types or files other than specified types (for example, graphics files such as *.jpg are often sequentially numbered.
[0044] A web crawling agent may also employ a method for identifying data files that are stored on a file server of one web site but not referenced in any hypertext coding on that website. In this embodiment, the software crawls through a directory and identifies hypertext files. Similarly, all non-hypertext files that exceed a user defined size threshold are marked. Then, each of the hypertext files is analyzed by the software in a search for references to the data files previously identified. Any data file that is not referenced by a hypertext file in that directory may marked as low priority or illicit. It should be appreciated that many other methods for classifying files are possible, and will of necessity be adapted as the Internet and its uses evolve over time.
[0045] According to an embodiment of the invention, bandwidth regulation—i.e., the applied rule set—is modified based upon geographic origin of the request and/or language of the request. The geographic origin of a request may be determined from a purchased table of IP addresses and location. Also, the language of an HTTP request from any major browser software may be determined from a language preference command in the request header. In the alternative, language may be used as an indicator for location or origin. For example, a message requesting EN-GB, which stands for English, Great Britain dialect, is most likely located in Great Britain. The rule set may be configured to restrict traffic from or to certain geographic areas or in designated languages. For example, by throughput rate to people requesting content in Japanese may be limited to a portion, such as 60%, of comparable rates for requests designating EN-US (English-U.S.). The economic benefit of this approach may be substantial. For example, if a free web hosting operation is able to sell ads for all Japanese traffic for $1 per 1000 displays, but on English-US displays the price is $5 per 1000 displays, an enormous financial benefit may follow from reducing Japanese traffic in favor of EN-US traffic when bandwidth limitations require a reduction in traffic. Vice-versa, if the rate for Japanese-language display ads is higher, the English-US traffic may be reduced.
[0046] Having thus described a preferred embodiment of a method and apparatus for improving bandwidth efficiency in a computer network, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. The invention is further defined by the following claims. | A method for operating a server to improve bandwidth efficiency in a computer network is disclosed. The server is operable to transmit files between a memory of the server and destinations on the computer network through a communication link having a finite bandwidth. The files are distinguishable by type and the server is provided with a rule set for prioritizing transmission of files by type. The method comprises monitoring a bandwidth usage of the communication link, and triggering application of the rule set when the bandwidth usage exceeds a threshold amount. The threshold amount is determined relative to the finite bandwidth. The method further comprises distinguishing between the files according to type, and prioritizing transmission of the files according to type and according to the rule set. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional application Ser. No. 62/303,682, filed Mar. 4, 2016, the entirety of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates, in general, to garment racks and, in particular, to racks for the air drying of garments following laundering.
[0004] 2. General Background of the Invention
[0005] Drying racks for garments have been in use for some time. The use of such racks in lieu of conventional electric or gas-powered dryers may be desirable for several reasons, including cost savings, and for the drying of articles that may shrink or otherwise be damaged as the result of the application of heated air, the accompanying tumbling of the articles, or both.
[0006] One type of garment drying rack, often preferable to use where a limited amount of space is available, is a folding rack capable of being mounted to a door. An example of a prior art drying rack of this general type is disclosed in U.S. Pat. No. 8,844,737 to Bukowski. These drying racks typically include one or more foldable drying panes having a plurality of rods from which wet or damp garments may be hung or suspended for drying, and hooks for suspending the overall drying rack from the top edge of a door, such as an interior door of a dwelling.
[0007] Most interior doors of dwellings are constructed of wood or another opaque material, and, as a result, an over-the-door mounted drying rack is typically not visible from the side of the door that opposes the side on which the drying rack is mounted. One potential resultant issue with this type of garment drying rack is the potential to dent, scratch, or otherwise mar the appearance of an opposing wall, in the event a door to which the garment rack is attached is swung open, particularly from the side of the door from which the rack is not visible, thereby causing the garment rack to strike a portion of the opposing wall. The risk of marring the opposing wall is heightened when the drying pane of the drying rack is left in a deployed or open position.
[0008] Accordingly, it is an object of the present invention to provide an over-the-door mounted garment drying rack having a mechanism for inhibiting damage to an opposing wall on occasions where the associated door is inadvertently opened, particularly when a drying pane of the rack has been left in an opened or deployed position.
[0009] It is another object of the present invention to provide an over-the-door mounted garment drying rack having a mechanism for inhibiting damage to the drying rack on occasions where the associated door is inadvertently opened causing the drying rack to contact an opposing wall, particularly when a drying pane of the rack has been left in an opened or deployed position.
[0010] These and other objects and features of the present invention will become apparent in view of the following specification, drawings and claims.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention comprises an over-the-door drying rack having a generally rectangular stationary frame, a pivoting drying pane, hooks or other fasteners to secure the stationary frame to a door, and straps, hinges and clips to change the position of the drying pane with respect to the frame. The drying pane consists of horizontal parallel rods or wires connected to two transversely oriented rods or wires.
[0012] This invention provides two different positions for the drying pane: an open and a closed position. Each position provides different advantages. The angled or open position provides more spacing between the items for more efficient drying; the vertical or closed position is ideal for smaller space. The invention enables the user to hang several long items in parallel from the various rods of the drying pane, optimizing the hanging space with minimal depth. In an embodiment of the present invention, several linear meters of vertical hanging space is provided, with only 10 to 20 cm. of depth.
[0013] The hinge design at the bottom of the drying pane, and the strap and plastic clip at the top make it easy for the user to alternate or flip between open and close positions. No tools are required to do this and there is no need to take the drying rack down from the door to change these positions.
[0014] A flexible strap, string or other flexible material couples the drying pane to the drying frame proximate its top and makes it easy to switch between open and close position. This flexibility also reduces contact between the drying rack and an adjacent wall, making it easier to open and close the door without damaging the drying rack or the wall or the door.
[0015] Guards or protectors, in the form of rotatable and slidable bumpers coupled to portions of the pivoting drying pane, initially come into contact with an opposing wall, in the event a door to which the present drying rack is mounted is inadvertently swung open. These bumpers, which may be constructed of a plastic material, are the first portions of the overall drying rack to contact the opposing wall under such circumstances, and serve to reduce the possibility that the contacted wall surface or the drying rack may be damaged or marred by such contact. In particular, the rotatable and slidable mounting of the bumpers serve to reduce friction between the pivoting drying pane and the opposing wall as contact is initially made, and serve to enable the drying pane to more readily retract towards the closed position, without damaging the wall or the drying rack as the door is further opened towards the opposing wall.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 is an elevated perspective view of a garment rack of the present invention, with the drying pane in the open or deployed position;
[0017] FIG. 2 is an elevated perspective view of the garment rack of FIG. 1 , with the drying pane in the closed or retracted position;
[0018] FIG. 3 is an elevated left side view of the garment rack of FIG. 1 , with the drying pane in the open or deployed position;
[0019] FIG. 4 is an elevated left side view of the garment rack of FIG. 1 , with the drying pane in the closed or retracted position;
[0020] FIG. 5 is an elevated perspective view of a hanging hook, suitable for affixing and suspending the garment drying rack of FIG. 1 adjacent the surface of a door;
[0021] FIG. 6 is an exploded perspective view of a first embodiment of a rotatable bumper of the present invention; and
[0022] FIG. 7 is an exploded perspective view of a second embodiment of a rotatable bumper of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] While the present invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail, several specific embodiments, with the understanding that the present disclosure is intended as an exemplification of the principles of the present invention and is not intended to limit the invention to the embodiments illustrated.
[0024] An embodiment of the present garment drying rack 10 is shown in FIGS. 1-5 as comprising stationary member or frame 20 , pivoting member or drying pane 30 , locking clip 50 , straps 60 , rotatable and slidable bumpers 70 , and hanging hooks 80 . Stationary member 20 is releasably mountable adjacent a surface of a door, and comprises inverted U-shaped tubular member 21 having horizontal portion 22 and vertical portions 23 . Apertures 24 disposed through vertical portions 23 proximate their endpoints permit opposing ends of bottom crossbar 26 to be disposed and secured therein. End caps 26 are fitted into the bottom openings of vertical portions 34 of tubular member 21 . Guards 27 are resiliently clipped to bottom crossbar 26 and serve to protect the surface of a door to which the present garment drying rack 10 is suspended from being scratched or otherwise marred by stationary member 20 . Stationary member 20 may be constructed of steel or other relatively rigid material.
[0025] Pivoting member 30 comprises center region 31 , offset drying bar 35 , and angled stop member 40 . Center region 31 is generally planar, and includes two opposing side rails 33 and a plurality of drying bars 32 disposed in a parallel, spaced relationship from each other, each spanning the space between side rails 33 and permitting a plurality of articles of clothing to be simultaneously hung upon pivoting member 30 for drying. Offset drying bar 35 , which may be integrally formed with center region 31 , is disposed at an angle of approximately ninety degrees from drying bars 32 , providing a convenient surface for hanging additional garments for drying, even when pivoting member 30 is in its closed position. Side rails 33 each include an associated pivoting loop 34 , disposed about bottom crossbar 26 of stationary member 20 . This, in turn, permits pivoting member 30 to rotate or pivot about bottom crossbar 26 , and for pivoting member 30 to transition between its open and closed positions. Pivoting member 30 may be constructed of steel or other relatively rigid material.
[0026] Referring to FIG. 5 , a plurality of hooks 80 may be employed to suspend drying rack 10 from the top surface of a door. Each hook 80 includes curved supporting region 81 , attachable to horizontal portion 22 of stationary member 20 , and hanger region 82 , configured to overlie the top surface of a door. Two hooks are preferably disposed along the length of horizontal portion 22 of stationary member 20 and, may either be snap-fit to horizontal portion 22 , or permanently secured to horizontal portion 22 , such as with a screw or other suitable fastener. Hooks 80 may be constructed of steel or other relatively rigid material.
[0027] Angled stop member 40 is disposed at an interior angle of approximately one hundred twenty-five degrees from drying bars 32 , and serves to preclude drying bars 32 from reaching a completely vertical orientation upon movement of pivoting member 30 to its closed position. Upon movement of pivoting member 30 to its closed position, top crossbar 41 of stop member 40 engages a portion of locking clip 50 in a releasable, snap-fit manner. Another portion of locking clip 50 is secured to horizontal portion 22 of U-shaped tubular frame member 21 and, accordingly, the engagement of top crossbar 41 of stop member 40 by locking clip 50 serves to releasably secure pivoting member 30 in the closed position. In a preferred embodiment, angled stop member is integrally formed with center region 31 of rotating member 30 .
[0028] As best seen in FIG. 4 , when in the closed position, pivoting member 30 is disposed at an angle of approximately six degrees from the vertical. This angle permits drying rack 10 to take up a relatively small amount of horizontal space when in the closed position while, at the same time, providing enough of an angle for multiple garments to be suspended from individual drying bars 32 .
[0029] Upon the release of pivoting member 30 from securement to locking clip 50 and, in turn, from securement to stationary member 20 , straps 60 limit the opposing rotational movement of pivoting member 30 . In particular, each of two straps 60 includes a first attachment clip, or hoop 61 , disposed at one end of the strap and coupled to horizontal portion 22 of U-shaped tubular member 21 , and a second attachment clip, or hook 62 , disposed at the opposing end of the strap and coupled to top crossbar 41 of pivoting member 30 . Upon full extension of strap 60 , which may be constructed of a metallic wire, a synthetic or natural fabric cord, or other suitable material, pivoting member 30 is in its fully open position, and is disposed at an angle of approximately thirty-two degrees from the vertical.
[0030] As compared to the closed position of pivoting member 30 , this angle permits additional lateral spacing between the individual drying bars 32 of center region 31 while, at the same time, still permits overall drying rack 10 to occupy a relatively narrow space adjacent a door to which the rack is affixed. Moreover, having the pivoting member 30 in a less than horizontal orientation upon full deployment facilitates the movement of pivoting member 30 towards its closed or retracted position upon contact of rotatable and slidable bumpers 70 with an adjacent wall upon the opening of a door to which the present drying rack 10 is attached. Alternatively, straps 60 may be manually unhooked or disconnected from pivoting member 30 , in which case center region 31 and drying bars 32 will further rotate until offset drying bar 35 contacts the surface of the door to which rack 10 is affixed, placing drying bars 32 in a substantially horizontal orientation.
[0031] Pivoting member 30 further includes two opposing rotatable and slidable bumpers 70 , each disposed about an associated side rail of angled stop member 40 , proximate the junction of stop member 40 and center region 31 of pivoting member 30 . Each rotatable and slidable bumper is both rotatable about and slidable along its associated side rail. Accordingly, in the event that a door to which drying rack 10 is affixed is swung fully open while rack 10 is in its open configuration, the first portions of drying rack 10 to come in contact with an opposing wall will be rotatable and slidable bumpers 70 , which are both rotatable and slidable about their associated side rail of stop member 40 . Moreover, as the door is more fully opened following initial contact of bumpers 70 and the adjacent wall, each bumper 70 remains in contact with the adjacent wall, as contact with the wall and further movement of the door causes pivoting member 30 to move from its open position, with straps 60 fully extended, towards its closed position. This rotational and slidable capability serves to lessen the friction between rotating member 30 and the adjoining wall, as pivoting member 30 is pushed towards the closed position by reason of the wall and door coming into further proximity.
[0032] Although, in the embodiment of FIGS. 1-4 , each bumper 70 is fixed for lateral rotation about an axis comprising the generally vertically oriented side rail of stop member 70 , and is fixed for vertical sliding movement along such axis, each bumper 70 may alternatively be disposed about the topmost drying bar 32 of center region 31 of pivoting member 30 . In such an embodiment, each bumper 70 is instead fixed for vertical rotation about an axis comprising a generally horizontally oriented drying bar, at the positions denoted by reference numeral 85 in FIGS. 1 and 2 , and is fixed for horizontal sliding movement along such axis.
[0033] Referring to FIG. 6 , rotatable and slidable bumper 70 is generally toroidal in shape and comprises two hemispherical members 71 , each having a plurality of semicircular bearing surfaces 72 , which contact and rotate about a portion of angled stop member 40 or another suitable cylindrical member of drying rack 10 . Each hemispherical member 71 further includes a resilient arm 73 having an end tab 74 , configured for snap-fit engagement with an aperture 75 of an opposing hemispherical member 71 . In this manner, a pair of identically-configured hemispherical members 71 can be snap-fit together about a suitable cylindrical member, with bearing surfaces 72 permitting relatively low friction rotation of rotatable and slidable bumper 70 about the cylindrical member. A plurality of optional locating fingers 76 , 77 serve to further preclude each hemispherical member 71 of rotatable and slidable bumper 70 from twisting or lateral rotation, relative to each other. Rotatable and slidable bumper 70 may be constructed of a suitable plastic material, such as, for example, high density polyethylene (HDPE).
[0034] Referring to FIG. 7 , an alternatively constructed rotatable bumper 90 is likewise generally toroidal in shape, and comprises two hemispherical members 91 , each having a plurality of semicircular bearing surfaces 92 , which contact and rotate about a portion of angled stop member 40 or another suitable cylindrical member of drying rack 10 . Each hemispherical member 91 further includes a plurality of posts 93 , configured for snap-fit engagement with a corresponding socket 94 of an opposing hemispherical member 91 . In this manner, a pair of identically-configured hemispherical members 91 can be snap-fit together about a suitable cylindrical member, with bearing surfaces 92 permitting relatively low friction rotation of rotatable bumper 90 about the cylindrical member. Internal webbing 95 serves to further strengthen each rotatable bumper 90 , and to further support the inner-most bearing surface 92 .
[0035] 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 other than as specifically described. Various modifications, changes and variations may be made in the arrangement, operation and details of construction of the invention disclosed herein without departing from the spirit and scope of the invention. The present disclosure is intended to exemplify and not limit the invention. | An over-the-door garment drying rack has a stationary frame affixable to a door, and a drying pane pivotably coupled to the stationary frame. At least one rotatable and slidable bumper is coupled to the drying pane and fixed for rotation and slidable movement relative to the drying pane. Upon opening of the door when the drying rack is in an open configuration, the bumper comes into contact with an adjoining wall surface prior to any other component of the drying rack. The rotatable and slidable nature of the bumper serves to protect the wall and the drying rack and to further inhibit damage or marring to the wall or the drying rack that may otherwise occur as a result of contact between the drying pane and the wall. | 3 |
FIELD OF THE INVENTION
The present invention is directed to a lavatory flush valve, and more particularly to a solenoid operated flush valve which is automatically operated in response to an electronic sensor.
A conventional lavatory flush valve is a diaphragm-type valve which is operated by a user by actuation of an external handle. Upper and lower chambers are separated by a flexible diaphragm and are filled with water supplied by a water inlet. The water outlet is connected to a urinal or the like fixture. Fluid flow communication between the upper and lower chambers and the outlet occurs by actuation of the handle and flexing of the diaphragm. The handle may be replaced with an appropriate device for causing automatic operation of the valve.
There is a need for a solenoid operated flush valve and an easily substitutable flow control adapter valve insert therefore, which are simple in construction and easy to repair.
OBJECTS AND SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a retrofit kit permitting a manually operable flush valve for automatic operation.
Another object of the present invention is to provide a flow control adapter valve insert for a solenoid operated flush valve.
Yet another object of the present invention is to provide a solenoid operated flush valve which is simple in construction and easy to repair and maintain.
A further object of the present invention is to provide a solenoid operated flow control adapter valve insert which can be easily substituted for the manually operated valve insert generally included in a conventional lavatory flush valve.
A solenoid operated flush valve has a main flush valve body including water inlet and outlet means. The main flush vale body includes generally horizontally extending nipple means which is in fluid communication with the water inlet and outlet means. A flow control means is removably mounted within the nipple means and includes valve insert means and solenoid means in cooperative engagement with the valve insert means. The valve insert means includes first and second ends and a side. The valve insert means includes a first passageway extending axially between the first and second ends thereof and a second passageway extending between one of the first and second ends and the side of the valve insert means. The second passageway is in fluid communication with the water outlet means through the side of the valve insert means. Means cooperate with the solenoid means for selectively blocking the second passageway to thereby regulate the flow of flushing water through the flush valve.
A solenoid operated flow control adapter valve insert for a flush valve has flow control means that includes valve insert means and solenoid means in cooperative engagement with the valve insert means. The valve insert means includes first and second ends and a side. The valve insert means includes a first passageway extending axially between the first and second ends thereof and a second passageway extending between one of the first and second ends and the side of the valve insert means. The solenoid means includes a reciprocable plunger which is movable therein and cooperates with and is in alignment with the valve insert means for selectively sealing the second passageway. The plunger moves away from the valve insert means when the solenoid means is activated for opening the second passageway.
The method of converting a manual flush valve to an electrically operated flush valve includes providing solenoid valve insert means having fluid inlet and fluid outlet means, a proximity sensor, and means for connecting the insert means and the sensor to a power source. The manual flush valve includes a main valve body having water inlet and outlet means, a generally horizontally extending nipple means, securement means mountable on the nipple means, and a manually operated valve insert means removably mounted in the nipple means. The method includes removing the securement means from the nipple means and then removing the manually operated valve insert means from the nipple means. The solenoid valve insert means is then inserted into the nipple means and is positioned so that the fluid inlet means extends along a first axis and the fluid outlet means extends along an axis generally transverse thereto. The securement means is repositioned on the nipple means and a proximity sensor is mounted adjacent the flush valve. The proximity sensor is electrically connected to the solenoid valve insert means.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages and novel features of the present invention will become apparent from the following detailed description of the preferred embodiment of the invention illustrated in the accompanying drawings, wherein:
FIG. 1 is a fragmentary elevational view partially in section of the flush valve of the invention shown mounted on a wall of a lavatory;
FIG. 2 is a cross-sectional view taken along lines 2--2 of FIG. 1, with portions omitted for clarity;
FIG. 3 is a cross-sectional view taken along lines 3--3 of FIG. 1, with portions omitted for clarity;
FIG. 4 is a fragmentary elevational view partially in section of the flush valve of the present invention in operation;
FIG. 5 is an exploded perspective view of the solenoid operated adapter valve insert of the invention;
FIG. 6 is an enlarged side elevational view of the portion marked within the circle in FIG. 5;
FIG. 7 is an enlarged cross-sectional view of the valve insert of FIG. 5; and
FIG. 8 is an end elevational view of the valve insert taken in the direction of arrow X in FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
The flush valve A of the present invention, as best shown in FIG. 1 and 4, includes main flush valve body 10 having water inlet 12 and water outlet 14. Flush valve A is mounted to lavatory wall B, and is electrically connected to infrared sensor assembly C.
The flush valve A further includes a horizontally extending nipple 16 which is diametrically opposite water inlet 12 and extends along axis 18. Water outlet 14 extends along longitudinal axis 20 which is transverse to axis 18.
The flush valve body 10 includes a vertically extending replaceable seat 22 positioned centrally therein coaxial with water outlet 14. A cast cap 24 is disposed directly above replaceable seat 22. The replaceable seat 22 is cylindrical in shape and accommodates slidable diaphragm guide 26. A diaphragm assembly, including diaphragm 28 made of a flexible material and resilient washer 30, is mounted atop guide 26 by screw 32 and fiber gasket 34. As best shown in FIG. 4, diaphragm 28 is securely held in a water-tight manner about its peripheral edge 36 between cast cap 24 and main valve body 10. A washer 38 and silencer device 40 are disposed below diaphragm 28.
As best shown in FIGS. 1 and 2, diaphragm guide 26 is cylindrical in shape and includes three radially extending vertical ribs 42 disposed peripherally on guide body 44. Ribs 42 are equiangularly disposed about guide body 44 and abut internal wall 46 of seat 22. Ribs 42 define flow channels 48. As best shown in FIG. 1 and 4, ribs 42 and channels 48 are formed generally in the lower half portion of guide 26 such that when diaphragm 28 is seated on seat 22, no fluid communication is made between flow channels 48 and water inlet 12.
The main flush valve body 10 includes upper chamber 50 separated from lower chamber 52 by diaphragm 28. Lower chamber 52 is in fluid communication with water inlet 12, and communicates with upper chamber 50 via opening 55 of fill passageway 54. As best shown in FIG. 4, a regulating screw 56 is provided in cast cap 24 for controlling the flow of water through passageway 54. Flush passageway 58 in cast cap 24 is diametrically opposite fill passageway 54 and communicates with flush chamber 60 in main flush valve body 10. The chamber 60, as best shown in FIGS. 1 and 4, is in fluid communication with nipple 16. A cover 59 is mounted over cap 24 by a conventional screw 61.
A solenoid operated flow control adapter valve insert assembly, generally indicated as D and shown in detail in FIG. 5, is inserted in nipple 16 and is in fluid communication with chamber 60. The adapter assembly D includes electrically operated solenoid 62 with spool 64 and generally cylindrical valve insert 66. A generally cylindrical, T-shaped plunger 68 reciprocally moves within cylindrical opening 70 of spool 64. The opening 70 does not extend the length of spool 64, and is closed adjacent end face 72 of spool 64. A coil-spring 73 is biased between plunger 68 and end face 72. The spool 64 preferably is made of steel and has screw-threads 74 on end portion 76 thereof. The threads 74 engage with corresponding threads 78 in conventional nut 80. The nut 80 secures spool 64 within solenoid 62.
The adapter assembly D further includes mounting sleeve 82 with screw-threaded end 84 disposed between spool 64 and solenoid 62. The sleeve 82 defines a passageway 86 therein that extends between ends 88 and 90. The passageway 86 has a diameter greater than the diameter of insert 66, so that valve insert 66, spool 64, and plunger 68 may easily slide therein. As best shown in FIGS. 1 and 4, when adapter assembly D is mounted within nipple 16, end 84 engages corresponding screw-threaded end 92 of nipple 16 for mounting the adapter assembly D therein. In FIG. 5, reference numeral 94 designates a conventional washer that is positioned between sleeve 82 and solenoid 62. Electric cables 96 connect solenoid 62 with sensor C.
As best shown in FIG. 6, plunger 68 includes at end 98 a resilient gasket 100. Gasket 100 includes chamfered nipple 102 projecting coaxially from gasket 100. When flush valve A is not in operation, gasket 100 and nipple 102 engage end 104 of insert 66 in a water-tight manner, described below in more detail.
As best shown in FIG. 7, valve insert 66 includes projection 106 extending coaxially from end 108 and recess 110 extending inwardly from end 104 thereof. A passageway 112 extends between projection 106 and recess 110 and includes openings 114 and 116. The passageway 112 has a diameter which is uniform throughout its length. The passageway 112 is in fluid communication with flush chamber 60 via opening 114 at one end, and opens into recess 110 by opening 116 at the other end thereof. It should be noted that although passageway 112 has been shown as extending generally parallel to side 118 of insert 66, it is well within the scope of the invention to vary the orientation thereof.
A generally L-shaped passageway 120 extends between end 104 of insert 66 and side 118 thereof, and communicates with recess 110 via opening 122 at one end, and opens into base chamber 126 via opening 124 in side 118, at the other end thereof, as best shown in FIGS. 1 and 4. The passageway 120 includes let 128 which extends parallel to passageway 112, and leg 130 which extends generally transverse thereto. The passageway 120 has a diameter which is uniform throughout its length, including both legs 128 and 130. The diameter of passageway 120 corresponds with the diameter of passageway 112. As best shown in FIG. 7, leg 128 extends generally along central longitudinal axis Y of insert 66. On the other hand, passageway 112 is parallel to and spaced from axis Y, as best shown in FIG. 8. Recess 110 includes inner and outer angularly disposed perimeter surfaces 132 and 134, respectively.
As best shown in FIG. 7, a radially extending peripheral groove 136 is provided on valve insert 66 for accommodating conventional o-ring 138 therein. Another o-ring 140 is disposed around projection 106. When the adapter assembly D is mounted within nipple 16, o-ring 140 seals opening 142 in flush valve body 10 through which projection 106 extends, and prevents back flow of water from insert 66 to flush chamber 60. Likewise, o-ring 138 substantially seals and prevents back flow of water from recess 110 to chamber 60. As best shown in FIG. 7, leg 130 of passageway 120 is disposed between o-rings 138 and 140.
As best shown in FIG. 7, valve insert 66 includes larger diameter section 144 and small diameter section 146. Preferably, the length of smaller diameter section 146 is less than the length of larger diameter section 144.
As best shown in FIG. 7, leg 128 of passageway 120 runs the length of smaller diameter section 146 and a portion of the length of larger diameter section 144. The leg 130 of passageway 120, however, extends transversely thereto within larger diameter section 144. Passageway 112 extends through the length of projection 106, larger diameter section 144 and the smaller diameter section 146, but short of recess 110. Further, leg 130 of passageway 120 is disposed adjacent projection 106 and away from recess 110.
As best shown in FIG. 3, clearance 148 between nipple 16 and valve insert 66 is provided. Due to clearance 148, it is not necessary that side opening 124 of L-shaped passageway 120 be aligned with base chamber 126 when the adapter assembly D is installed in nipple 16 since, when flush valve A is activated (described below in detail), water from recess 110 will make its way to base chamber 126 through clearance 148. Therefore, clearance 148 increases the ease of installing adapter valve assembly D since one need merely insert assembly D into nipple 16 without being concerned about the alignment of leg 130 of passageway 120 with base chamber 126.
As best shown in FIG. 1 and 4, when the insert assembly D is installed in nipple 16, passageway 112 and leg 128 of passageway 120 run generally parallel to nipple 16, while leg 130 of passageway 120 runs generally transverse thereto. Recess 110 is always full of water, since passageway 112 is in constant fluid communication with flush chamber 50 and its opening 116 in recess 110. Passageway 120, on the other hand, communicates with base chamber 126 and recess 110 via openings 124 and 122, respectively. As a result, retraction of plunger 68 by energization of solenoid 62 causes the water in recess 110 to flow immediately to clearance 148. This assumes that diaphragm 28 flexes almost instantly in order to cause operation of the valve D.
USE AND OPERATION
A manually operated flush valve is converted to an electrically operated flush valve by first removing the conventional handle assembly (not shown) from its nipple 16. Then, the solenoid operated flow control adapter valve insert assembly D of the invention is inserted into the nipple 16. The assembly D is positioned in the nipple 16 so that projection 106 of insert 66 is firmly seated in opening 142 of valve body 10. As discussed above, it is not necessary that leg 130 of passageway 120 be aligned so as to open into base chamber 126. Subsequently, sleeve 82 is screwed tight on nipple 16, an nut 80 is secured tight over end 76 of spool 64. The cables 96 are then connected to sensor assembly C.
When the flush valve is not in operation, upper and lower chambers 50 and 52 are filled with water at supply line pressure. Upper chamber 50 receives water via fill passageway 54 which is in fluid communication with lower chamber 52 via opening 55. Therefore, the pressures on both sides of diaphragm 28 are the same and diaphragm 28 remains firmly seated on upper surface 150 of seat 22, since diaphragm 28 is biased into the closed position. As shown in FIG. 1, upper chamber 50 is in fluid communication with recess 110 via passageway 58, chamber 60 and passageway 112. However, opening 122 of L-shaped passageway 120 is closed because of abutting plunger 68, and any water present in recess 110 does not flow to base chamber 126 via passageway 120.
The flush valve A is rendered operative by a lavatory user stepping in front of sensor assembly C. This transmits an electrical signal to the solenoid 62 for causing operation thereof. When solenoid 62 is activated upon receiving the signal from sensor C, plunger 68 moves within spool 64 away from valve insert 66, as best shown in FIG. 4, and the water present in recess 11 begins to flow through passageway 120 into base chamber 126 and to water outlet 14.
When the water begins to flow through passageway 112 to passageway 120 via recess 110, the pressure in upper chamber 50 is reduced, thereby creating a pressure differential with lower chamber 52. The differential causes diaphragm 28 to be flexed upwardly, as best shown in FIG. 4, thereby permitting water to flow through flow channels 48 to outlet 14, as shown by arrows 154 in FIG. 4.
When solenoid 62 is deactivated, for example, by the absence of a user from the field of vision of the sensor C, plunger 68 reciprocates back to its initial blocking position due to the force exerted by spring 73. This closes opening 122 of valve insert 66. As a result, the water from chamber 60 and recess 110 stops flowing and begins to accumulate therein and in upper chamber 50. This causes the pressure in chamber 50 to rise and eventually be equalized with the pressure in lower chamber 52. Accordingly, diaphragm 28, due to the balanced pressure in upper chamber 50 and its internal bias, returns to its initial blocking position, shown in FIG. 1. The flow channels 48 are no longer in fluid communication with lower chamber 52 and, therefore, the water from chamber 52 stops flowing to outlet 14 via flow channels 48.
While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, uses and/or adaptations of the invention and following in general the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the present invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention or the limits of the claims appended hereto. | A solenoid operated flush valve has a main flush valve body including water inlet and outlet means. The main flush valve body includes generally horizontally extending nipple means which is in fluid communication with the water inlet and outlet means. A flow control means is removably mounted within the nipple means and includes valve insert means and solenoid means in cooperative engagement with the valve insert means. The valve insert means includes first and second ends and a side. The valve insert means includes a first passageway extending axially between the first and second ends thereof and a second passageway extending between one of the first and second ends and the side of the valve insert means. The second passageway is in fluid communication with the water outlet means through the side of the valve insert means. Means cooperate with the solenoid means for selectively blocking the second passageway to thereby regulate the flow of water flushing through the flush valve. | 4 |
CROSS REFERENCE TO A RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 61/984,912, entitled Expansion Joint Straightener/Control Joint Tool, which was filed on Apr. 28, 2014, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tool for facilitating the straightening of expansion joints in concrete construction and establishment of control joints therein along with related methods.
2. Description of the Prior Art
When pouring concrete slabs, expansion joints are needed for expansion and contraction that occurs in response to temperature changes in the weather and control joints are needed to help control cracking of the concrete as it cures.
Setting an expansion joint is a difficult aspect of concrete construction. In order to make the finished product look professional and attractive, it is essential that the expansion joint be straight, without any kinks, curves, or slants in it over its entire length. This “straightening” of the expansion joint has traditionally been done visually. This requires the worker to stand to look at the expansion joint, then bend to tap it into place at various locations, standing to look at it again, going back on his or her knees to tap it into place this way or that, standing to look at it again, back down on your knees to make any further adjustments, standing again, until the desired result is achieved. This is an iterative process that could go on for five to ten cycles before the expansion joint is only visually straight, but may not be truly straight, thereby resulting in an aesthetically inferior expansion joint set.
There remains, therefore, a very real and substantial need for an improved means of providing a straight expansion joint in concrete construction and to provide appropriate control joints.
SUMMARY OF THE INVENTION
The tool of the present invention also eliminates the iterative and inefficient process of getting up and down multiple times by providing a perfectly straight expansion joint. With one pass of the tool forward and one pass backward, a straight expansion joint is achieved, giving the concrete work a beautiful, professional appearance. The tool has a manually engageable handle secured to an underlying base. The base has a downwardly open elongated, generally centrally located expansion joint receiving channel and a pair of generally upwardly projecting parallel flanges adjacent to the lateral edges thereof.
The tool and related method of the present invention also provides an efficient means of establishing a control joint by placing an insert piece into the tool and effecting tool movement.
It is an object of the present invention to provide an expansion joint straightener tool and associated method which facilitates providing a straight expansion joint.
It is another object of the present invention to provide such a tool and associated method which facilitates employing a tool insert piece to create straight control joints.
It is yet another object of the present invention to provide such a tool and associated method wherein a downwardly projecting expansion joint guide channel and upwardly projecting straight edge guide flanges contribute to achieving the desired straight expansion joint.
It is a further object of the present invention to provide a uniquely configured control joint insert for use with the tool and associated method of the present invention.
These and other objects of the invention will be more fully understood from the following description of the invention on reference to the illustrations appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the expansion joint straightener tool of the present invention.
FIG. 2 is right side elevational view of the tool of FIG. 1 .
FIG. 3 is a left side elevational view of the tool of FIG. 1 .
FIG. 4 is a top plan view of the tool of FIG. 1 .
FIG. 5 is a bottom plan view of the tool of FIG. 1 .
FIG. 6 shows an exploded view of the tool of FIG. 1 .
FIG. 7 shows a cross-sectional view of a concrete slab in combination with the tool of the present invention.
FIG. 8 shows a cross-sectional view of a concrete slab with the tool of the present invention having a control joint establishing insert in position.
FIG. 9 is a front elevational view of a control joint tool of the present invention.
FIG. 10 is a left side elevational view of the control joint insert of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 through 6 , there is shown the hand tool of the present invention which provides an efficient means for a straightening an expansion joint in a newly poured concrete slab. The hand tool has a handle 20 which, in the form shown, has a pair of openings 38 , 39 for receipt, respectively, of bolts 22 , 23 which pass through the openings respectively, and have their lower ends secured to plate 26 as by welds 19 , 21 , for example. Plate 26 is, preferably, made from steel, such as a stainless steel. The upper portions of bolts 22 , 23 pass through the openings 38 , 39 , respectively, and are secured in position by nuts 24 , 25 .
To facilitate manual engagement by the user, the handle 20 has a generally downwardly concave configuration, to provide space between the handle and plate 26 for manual engagement thereof.
The free ends of the handle 20 are tapered generally outwardly as identified by reference number 40 , 41 . The tapered portions 40 and 41 of the handle 20 serve as a centering guide to visually assist in centering the tool over the expansion joint.
With reference to FIG. 7 and 8 , it will be seen that the outer surfaces of generally parallel flanges 34 , 35 are structured to engage straight edges positioned exteriorly thereof, such as straight edge 44 which has surface 45 in contact with the outer edge of flange 35 as shown in FIG. 7 and straight-edge 52 having outer surface 53 in contact with the outer surface of flange 34 ( FIG. 8 ). In this manner, through the use of at least one such straight edge 44 , 52 which is positioned generally parallel to the expansion joint and are normally or otherwise restrained against movement. The straight edge 44 , 52 may be a wooden 2 by 4 , for example. The hand tool may be moved in a straight line with the expansion joint received within channel 36 in a first direction to straighten the expansion joint and reciprocally moving back toward the starting point to further straighten the expansion joint. This creates an efficient means of rapidly creating the desired straight configuration for the expansion joint without having to engage in the burdensome prior art practices.
The tool has a downwardly open expansion joint guide channel 36 which receives the expansion joint 49 . This channel is defined by flanges 32 , 33 of respectively elements 28 , 29 which are preferably secured to the underside of plate 26 by any suitable means such as welds 30 , 31 , for example. At the other side of channel defining plates 28 , 29 are a pair of generally upwardly directed parallel flanges 34 , 35 which provide straight edges for guiding the hand tool. The curved transitions 37 , 43 disposed between the generally straight portions 47 , 48 of channel defining plates 28 , 29 and their respective flanges 32 , 33 serve to define the contour of the finished edge of the concrete on opposite sides of the expansion joint. These may be of any desired radius depending upon the desired finished appearance.
As shown in FIG. 7 , concrete slab 46 has an upper surface 48 which is structured to support the tool of the present invention as it moves through the expansion joint 49 which is received with channel 36 between flanges 32 , 33 in order to straighten the joint.
As shown in FIG. 8 , concrete slab 50 has upper surface 51 which supports the tool of the present invention for relative sliding movement thereof.
Referring to FIGS. 8 and 9 , reference will be made to an additional feature of the present invention wherein a control joint which is well known in concrete construction is established in a unique manner employing the tool of this invention. A control joint serves to resist undesired cracking of the concrete. In the present invention, as shown in FIG. 8 , the tool of the present invention has a downwardly open channel 36 which is structured to receive a control joint piece 60 for positioning within concrete slab 50 . Referring to FIGS. 9 and 10 , certain details of the control joint piece 60 will be considered. The control joint piece 60 has a generally flat upper surface 62 and two surfaces 68 , 70 tapering toward the bottom. The leading edge 64 is curved so as to facilitate movement thereof through the concrete and the trailing edge is generally flat. This enables the tool to function in one mode as an expansion joint guide for straightening the expansion joint and, in another mode, where it is desired to create the control joint, the tool for creating the same by inserting the control joint piece 60 followed by moving the tool through the concrete where the control joint is desired to he established.
Whereas particular embodiments of the invention have been described herein for purposes of illustration, it will be appreciated by those skilled in the art that numerous variations of the details may be made without departing from the invention as described in the appended claims. | A tool for concrete construction has a base provided with downwardly open channel for receiving an expansion joint with movement of tool effecting straightening of expansion joint. Generally upwardly directed flanges are structured to be cooperating with a straight edge for facilitating straight movement of tool during straightening of expansion joint. The tool may also be employed to establish control joints. Related methods are provided. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to novel coating apparatus for applying multiple superposed coatings to the surface of a moving web, and more particularly to coating apparatus in which layers of coating solutions cascade onto a moving web and are thereafter set or gelled.
Known cascade coating apparatus is capable of applying a plurality of separate coatings onto the surface of a moving web. The coatings are depositied onto the web from downwardly flowing coating solution lamina, superposed one upon another in a layer relationship, and thereafter gelled, or set, to produce an article having a plurality of substantially discrete superposed layers on the web base. Conventionally, the coating solutions have been applied to the web as the web is being supported by a roller, i.e., the web is curved in the direction of travel at the time of application of the coating solutions. The use of rotating rolls as web supports in combination with a stationary coating head apparatus has met with success; however, there are a number of disadvantages associated with such structures. For example, when attempting to coat at relatively high web speeds, particularly with high viscosity coating fluids, there have been such problems as air bubbles being entrapped under the coatings hereby providing nonuniformity of the coatings. Such problems have been minimized by applying a vacuum to the side of the web which is to be coated as the web passes around the rotating support roll. The use of a vacuum box in this position has to some extent stabilized the "bead" of the coating solution which forms at the point of contact of the coating solution with with the web. However, this approach has not been fully satisfactory due to, for example, the rotating backing roll, variations in flatness of the coating head facing the roll defects in the roll surface, film base flatness variations, etc. Because of the denoted problems, very small, e.g., substantially nonexistent, coating gaps are difficult to obtain on production machines without scraping at some point in the operation. Defects caused by the above cannot be tolerated in products such as photographic films in which substantially uniform coatings are necessary in order to achieve consistently good quality image reproduction.
Typical prior art patents relating to known structures of the type mentioned above are U.S. Pat. Nos. 2,761,419; 3,206,323; and 3,220,877. This invention is related to my invention described in U.S. Pat. No. 3,749,053.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a novel cascade coating apparatus which is capable of applying a plurality of superposed coating solutions onto a web at high throughput with a high degree of uniformity and no appreciable gap between the web and applicator.
Another object of the invention is to coat a web while it is travelling in a substantially straight path as distinguished from an arcuate path of web travel around a support roller.
A still further object of this invention is to provide a coating apparatus which may be run at high speed and is capable of coating a high viscosity web-contact layer and a lower viscosity upper layer.
In order to improve film coating stability, particularly at high web throughputs, and to obtain more uniform coatings on the web, a web is passed through what amounts to a substantially gapless coating applicator. Force is exerted upon the web which is to be coated to urge it toward contact with the coating applicator, i.e., upwardly against the coating head to reduce the gap between the coating head and the web. The web should not experience deviations from substantial flatness at the coating composition deposition area and will accordingly be free floating and will not abe supported by a backing roll at the deposition area.
The application of the coating solutions to the web while the web is running in a substantially straight path, in contradistinction to travelling around a support roll, has the advantage that after the coating solutions are deposited upon the web, they are not subjected to immediate bending as in the case with the prior art support rollers where stress is applied to the layers of coating solution due to the arcuate path of movement of the web. It is theorized that the bending of the web carrying the coatings tend to result in nonuniformities in the coatings. For example, upon unbending of the web, the upper surface of each coating will be contracted or compressed relative to the lower surface of the coating, which may result in some of the irregularities found in prior art laminated products. In addition, elimination of the support rolls provide the free-floating functionality aspect necessary to the practice of the present invention.
If it is desired to increase the rate at which the coatings gell upon contact with the web, the web may be precooled by spraying the web with a coolant upstream of the coating applicator.
In addition, in order to accommodate, for example, the passage of a splice in the web past the coating applicator the free floating aspect of this invention permits the web to slightly deviate from its path to accommodate the splice without tearing.
In accordance with one aspect of the invention, a pressure chamber may be provided adjacent the lower portion of the coating head at the point of application of the coatings to the web. The positive pressure provided by this chamber tends to press the web upwardly, thereby reducing, or substantially eliminating, the magnitude of any coating gap in order to achieve uniform coatings. Mechanical tensioning devices are also appropriate.
By employing the present invention, it has been found that persistent problems relating to solution viscosities and coating speeds have been overcome. With the present invention it makes little difference if the viscosity of the first layer is greater than the next layer. In general, the viscosities of materials employed in the first layer may be from one to a thousand or more centipoises. The web speed may be as high as 1,500 feet per minute or more. It is accordingly evident that the present invention provides a substantially viscosity independent multilayer coating apparatus wherein deposition rate and viscosity cease to be the limitations that they now are.
The above and other objects, features and advantages of the invention will become more apparent as this description proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view taken primarily in vertical longitudinal section of a presently preferred embodiment of the invention;
FIG. 2 is a view of another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein like reference numerals are used in the several views to designate like parts, and more particularly to FIG. 1, reference number 10 generally designates one embodiment of a cascade coating apparatus in accordance with the present invention. A web 12 which may be, for example, a film such as a cellulose acetate, polyethylene terephthalate, etc., initially has its surface cooled with a coolant such as air or preferably a volatile coolant such as methanol or freon from a spray head 14. Excess coolant falling off of the web may be collected in a tray 16 for recycle to the spray head. The web is precooled to a temperature which will expedite the gelling or setting of the coating solutions upon contact with the web in the coating head. It is then introduced to the coating area and passes surface 30 of the coating applicator, which preferably has a rounded leading edge and is at an appropriate angle to contact the web without abrasion, though the applicator may be adjusted so that the web passes close to surface 30 without actually contacting it.
A multiplicity of coating solutions represented in the FIG. 1 embodiment of two superposed layers or strata of coating solutions 42 and 44 flow down the inclined cascade plane outer or downstream surface 46 of the applicator, past lip 38 onto the web 12 where the coating solutions quickly set to form a laminated article. The coating solutions may be, e.g., a silver halide emulsion and a protective gelatin coating which are commonly employed in the manufacture of photographic film. As is well known in the art, the thicknesses of the resulting layers in the laminated article do not necessarily correspond to the thicknesses of the cascading coating solutions. The coating solutions are supplied to the coating head from reservoirs through conduits 48 and 50.
A passageway 56 is utilized to supply the bottom layer of coating solution to the web. This may be a surfactant material, or other material, and facilitates the coating of the main coating solution onto the web 12 by lubricating the web against the applicator area between the deposition point of the bottom layer and the cascade surface of lip 38, which area is generally defined as the coating composition deposition area.
Conventional mechanical tensioning means provides net upward pressure on the web section toward the applicator lip as indicated by the position of the rollers which, in this embodiment, is also the means for moving the web past the applicator. Accordingly, the moving web will tend to be pressed upwardly against the under surface of the coating lip 38 to minimize the gap between the web and the lip, which gap will effectively be equal to the web thickness of the bottom layer of coating material from passageway 56. Normally less than 0.001 inch gap above the web may be maintained. A force of about 15 pounds per square inch is adequate to urge the web toward the applicator.
It is a significant feature of the invention that the web 12 is substantially flat as it passes under the surface 38 and the coating solutions are deposited thereon. The now coated web is then drawn off in a substantially straight line so that the coatings may gell without being subjected to laminar problems which might be the case if the web was moving on a path around a roller as in the prior art. Increased processing speeds are also obtainable by the web arrangement of the invention.
Referring to FIG. 2, this is a view similar to FIG. 1 but of another embodiment of the invention. In this embodiment air enters chamber 74 through inlet 76 and acts upon the undersurface of the web 12 to urge the web toward the coating lip resulting in a substantially gapless coater as is the case with the FIG. 1 embodiment.
The term "free floating" as employed herein connotes a condition of a web whereby it is free to deviate from its path to accommodate splices, etc.
While presently preferred embodiment of the invention has been shown and described with particularity, it will be appreciated that various changes and modifications may readily suggest themselves to those of ordinary skill in the art on being apprised of the present invention. It is intended to encompass all such changes and modifications as fall within the scope and spirit of the appended claims. | Coating apparatus for depositing multiple layers of superposed coating compositions onto the surface of a moving web which is substantially flat in the region of application of the coating compositions and wherein the web maintains a substantially gapless relationship to the apparatus. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates generally to air conditioning and heat pump systems and more particularly, but not by way of limitation, relates to refrigerant coils used therein.
The typical indoor coil utilized with heating and cooling indoor equipment is conventionally of an inverted "V" configuration defined by two multi-row, multi-circuit fin/tube refrigerant coil slabs across which air to be cooled is flowed on its way to the conditioned space served by a furnace or air handler. Indoor coils of this type (commonly referred to as "A-coils" in the air conditioning industry) are offered in various nominal tonnages, one air conditioning "ton" being equal to an air cooling capacity of 12,000 BTU/HR. Furnaces and other air handling equipment using this type of coil are normally offered to the residential or commercial customer in an appropriate range of air conditioning tonnages which are established by the size of the A-coil installed in the furnace, or other type of air handler, in conjunction with the correspondingly sized condenser side of the overall refrigeration circuitry.
A representative air conditioning tonnage range for residential furnace applications is, for example, one to five tons, while a representative light commercial tonnage range would be from five to twenty tons. Within this overall cooling capacity range, the tonnage increment between successively larger capacity A-coils is typically 1/2, 1, 21/2 or 5 tons, with the tonnage increments usually being smaller at the lower end of the capacity spectrum.
Conventional refrigerant "A" coils have been the norm in this general furnace and air handler tonnage range for many years and have been, generally speaking, well suited for their intended purpose. However, they are also subject to a variety of well-known problems, limitations and disadvantages, particularly as pertains to their manufacture and incorporation in their associated furnaces, air handlers or the like.
For example, for each A-coil within a given multitonnage set thereof, it has heretofore been necessary to manufacture and inventory a differently sized pair of refrigerant coil slabs. As an example, if a manufacturer produces a line of heating and air conditioning equipment having a cooling range of from 11/2 to 20 tons, there may representatively be twelve different capacity A-coils needed-e.g., A-coils of 11/2, 2, 2 1/2, 3, 31/2, 4, 5, 71/2, 10, 121/2, 15 and 20 ton nominal air cooling capacities. Accordingly, twelve differently sized refrigerant coil slabs must be manufactured and inventoried.
This conventional necessity increases both tooling costs and manufacturing floor space requirements, thereby also increasing the overall manufacturing costs associated with the air conditioning systems into which the A-coils are incorporated. Additionally, each of the A-coils in a necessary capacity range thereof will typically have different depths in the direction of intended air flow therethrough. For example, in up-flow furnaces, progressively larger capacity A-coils will have correspondingly increasing vertical installation height requirements. This can result in the necessity of oversizing the cabinet height of an air handler to accommodate A-coils of varying heights. Moreover, in an attempt to reduce the number of differently dimensioned refrigerant coil slabs which must be manufactured and inventoried to assemble A-coils of the necessary different refrigeration capacities, many manufacturers provide relatively large capacity increments at the upper end of their capacity range. For example, in light commercial air conditioning equipment, the highest capacity unit may be 20 tons, while the next smaller unit may be 15 tons. If the system designer determines that, for the conditioned spaced to be served by the equipment, an air conditioning capacity of 16 tons is needed, he normally must select the 20 ton unit. This undesirably results in a 25% oversizing of the air conditioning system.
In view of the foregoing, it can be seen that it would be desirable to provide a refrigerant coil structure, and manufacturing methods associated therewith, which eliminate or at least substantially reduce the above-mentioned and other problems, limitations and disadvantages heretofore associated with conventional "A-coils" used as the indoor coils of air conditioning and heat pump systems.
SUMMARY OF THE INVENTION
In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a series of identically sized flat refrigerant coil modules are utilized to form a plurality of air cooling or heating refrigerant coils of different nominal air conditioning tonnages, the coils having a different number of the modules arranged in an accordion pleated orientation.
Each of the identically sized modules is defined by a single row of parallel, laterally spaced apart heat exchange tubes serially interconnected to form a single refrigerant circuit having an inlet end for receiving refrigerant from a source thereof, and an outlet end for discharging the received refrigerant. A longitudinally spaced series of heat exchange fins are transversely connected to the heat exchange tubes.
The modular, accordion pleated fin/tube refrigerant coils of the present invention are particularly well suited as replacements for the two-slab "A-coils" conventionally incorporated in combination heating and air conditioning furnaces and the like and provide a variety of manufacturing and other advantages compared to such A-coils. For example, only one size flat refrigerant coil slab needs to be manufactured and inventoried since the accordion pleated refrigerant coil assemblies of the present invention are all fashioned from varying numbers of the identically sized coil modules. Additionally, the use of these identically sized coil modules permits the varying capacity coil assemblies which they define to have identical depths in the intended air flow direction across the coils. In turn, this permits the allocated dimensions of the coil housing or air handler, in the direction of air flow therethrough, to be essentially uniform for each furnace in a manufacturing series thereof.
Compared to conventional A-coils, the accordion pleated coils of the present invention, which are preferably defined by three or more coil modules, provide a substantially increased coil face area. For a given flow rate across the coils, during furnace or air handler operation, this increased face area reduces the coil face velocity of the air to a magnitude considerably below the minimum design velocity typically associated with A-coils. Specifically, the accordion pleated module coils of the present invention are preferably sized to provide operating face velocities in the range of from approximately 100 feet per minute to approximately 200 feet per minute.
While under conventional refrigerant coil design wisdom this unusually low coil face velocity is considered undesirable, it uniquely permits the accordion pleated modular coils of the present invention to be provided with very closely spaced heat exchange fins which are of an enhanced, slotted construction, to thereby substantially increase the air-to-fin heat exchange efficiency without increasing the air pressure drop across the accordion pleated coil to a level beyond that normally associated with conventional A-coils. Specifically, the modular coils of the present invention are designed to operate at an air side pressure drop of less than about 0.10".
To further improve the overall heat exchange efficiency of the accordion pleated coils, the primary heat exchange efficiency (i.e., the heat exchange occurring between the refrigerant and the coil tubes) is also increased by providing the tubes with an enhanced construction, preferably by forming internal grooves within the tubes.
In a preferred embodiment of the accordion pleated refrigerant coils, the identically sized refrigerant coil modules used to define the coils have a nominal air conditioning tonnage capacity of 0.5 tons (6,000 BTU/HR.). This, of course, provides the ability to set the coil-to-coil tonnage increments correspondingly at 6,000 BTU/HR. This very desirably reduced capacity increment, in turn, provides the system designer with the ability to very precisely match the indoor side of the overall air conditioning circuitry to the conditioned space building load requirements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut-away schematic perspective view of a representative forced air furnace or air handler having installed thereon a compact, modular refrigerant coil which embodies principles of the present invention;
FIG. 2 is an enlarged scale perspective view of the modular coil removed from the furnace;
FIG. 2A is a perspective view of the FIG. 2 modular coil in an alternate, horizontal air flow orientation thereof;
FIG. 3 is a perspective view of a representative larger tonnage version of the FIG. 2 modular coil;
FIG. 3A is a perspective view of the larger tonnage FIG. 3 modular coil in an alternate, horizontal air flow orientation thereof;
FIG. 4 is an enlarged scale, partially cut-away perspective view of one of the series of identically sized, single row single circuit refrigerant coil modules used to form the representative refrigerant coils shown in FIGS. 2, 2A, 3 and 3A;
FIG. 5 is an enlarged scale cross-sectional view through the refrigerant coil module taken along line 5--5 of FIG. 4;
FIG. 5A is an enlargement of the circled area "A" in FIG. 5; and
FIG. 6 is an enlarged scale partial cross-sectional view through an adjacent pair of enhanced heat exchange fins on the refrigerant coil module.
DETAILED DESCRIPTION
Perspectively illustrated in FIG. 1 is a typical indoor up-flow combination heating and cooling system 10 having incorporated therein a uniquely configured air-cooling evaporator coil 12 which embodies principles of the present invention. System 10 includes a housing 14 having a return air section 16 with a blower 18 disposed therein, and a coil housing section 20 disposed above the return air section 16. The coil 12, and a suitable air-heating structure 22 (such as an electric resistance heating coil or a fuel-fired heat exchanger) are operatively mounted within the housing section 20 and housing section 16, respectively.
During cooling operation of the system 10, return air 24 from the conditioned space served by the system is drawn into the housing return air section 16, by the blower 18, through a return duct 26 suitably connected to a housing opening 16 a . Return air 24 entering the housing section 16 is drawn into the blower inlet 28 and forced by the blower 18 upwardly across the heating/cooling coil 12. The cooled or heated air 24 is then flowed back to the conditioned space through a suitable supply duct 30 connected to top side opening 20 a in the housing section 20.
Turning now to FIGS. 2 and 4, according to an important feature of the present invention, the coil 12 (FIG. 2) is formed from four identically sized flat refrigerant coil modules 32 (FIG. 4) arranged in an accordion-pleated configuration and supported within the housing 20 which has an open top side 36 and an open bottom side 38. As illustrated, the coil 12 has a depth D extending parallel to the flow of air 24 externally across the coil. As depicted in FIG. 2A, the coil 12 may be repositioned, if desired, to provide for horizontal flow of the air 24 externally across the coil. In either the horizontal or vertical orientation of coil 12 the air flow across the coil may be opposite to that shown if desired.
Turning now to FIG. 4, the flat refrigerant coil module 32 utilized to form the modular coil 12 includes a single row of parallel, laterally spaced apart refrigerant heat exchange tubes 40 connected at their ends by conventional "U" fittings 42 to form a single refrigerant circuit having an open inlet end 44 and an open outlet end 46. Transversely connected to the heat exchange tubes 40 are a longitudinally spaced series of heat exchange fins 48. The coil 12 (FIG. 2) is operatively connected in the refrigeration circuit serving the system 10 by conventional refrigerant supply piping 50 connected to the tube inlets 44 of the coil modules 32 and provided with refrigerant expansion means 52, and refrigerant return piping 54 connected to the open tube outlets 46 of the four coil modules 32. If desired, the refrigerant flow through the coil modules 32 can be reversed simply by connecting the supply piping to the module outlets, and connecting the return piping to the module inlets.
With reference now to FIGS. 1 and 2, the coil 12 is supported within its associated housing 20 by means of two sets of interconnected support bars 55 secured to the opposite ends of the coil modules 32 and having slots 57 through which the U-fittings 42 outwardly pass. At their lower ends the bars 55 are connected to conventional drain pan means (not shown) that are fastened to housing 20. The coils depicted in FIGS. 2A, 3 and 3A are supported in a similar manner within their associated housings.
According to a key aspect of the present invention, as may be seen by comparing FIGS. 2 and 3, a series of identical flat refrigerant coil modules 32 may be utilized to form a series of modular, accordion-pleated refrigerant coils, having identical coil depths D and different nominal air conditioning tonnages depending upon the number of modules 32 utilized to form the particular accordion pleated coil. For example, the larger coil 56 shown in FIG. 3 is formed from ten of the identically sized modules 32 arranged in an accordion pleated fashion and operatively supported in an appropriately larger housing 20 a having an open top side 60 and an open bottom side 62. As may be seen by comparing FIGS. 3 and 3A, the larger coil 56, like the smaller coil 12, may be positioned in either vertical or horizontal air flow orientations
The refrigerant coil module 32 illustrated in FIG. 4 representatively has a nominal air cooling capacity of 0.5 tons (6,000 BTU/HR.). Accordingly, the modular coil 12 has a nominal air cooling capacity of 2.0 tons, and the larger coil 56 has a nominal air cooling capacity of 5.0 tons. It will be appreciated, however, that the nominal air conditioning tonnage of each coil module 32 could be greater or smaller if desired. It will also be appreciated that the two illustrated coils 12 and 56 are merely representative of a wide variety of accordion pleated coils that could be formed utilizing different numbers of identically sized coil modules 32, ranging from a two module coil to a coil having as many identically sized modules as is necessary to provide the required total air conditioning tonnage of the coil. For system applications, the minimum number of modules 32 utilized in a given coil is preferably three.
Compared to conventional "A"-coils utilized in systems such as the system 10 depicted in FIG. 1, the present invention's concept of utilizing selected numbers of identically sized coil modules to form accordion-pleated refrigerant coils of mutually different air conditioning capacities provides a variety of advantages. For example, as is well known, the production of A-coils of the different air conditioning capacities typically needed in a given equipment line necessarily entails the fabrication and inventorying of several differently sized refrigerant coil slabs used to form the A-coils. This, of course, requires increased production machinery and associated manufacturing floor space. Additionally, to accommodate the differently sized refrigerant coil slabs, it is necessary to produce a corresponding number of differently sized heat exchange fins. Moreover, the air conditioning capacity increments between successively larger A-coils, particularly at the upper end of the equipment's capacity spectrum, is typically considerably larger than 0.5 tons. This often results in the necessity of considerably oversizing the system's actual air conditioning capacity compared to the calculated air conditioning requirement for the conditioned space served by the system.
In the present invention, however, it is only necessary to fabricate and inventory refrigerant coil slabs of a single size to produce all of the different capacity coils needed in a typical equipment line. This advantageously reduces the overall coil manufacturing costs, thereby reducing the overall manufacturing costs of the system 10. Another advantage provided by the coil manufacturing method of the present invention is that the incremental air conditioning capacity increase between successively larger accordion pleated coils may be advantageously made uniform, and quite small, throughout the air conditioning capacity range of the particular equipment line. Using the illustrated coil module 32 as the "building block" for a series of different capacity air conditioning coils, this uniform increment would be 0.5 tons. The ability to economically provide this small air conditioning capacity increment permits the air conditioning capacity of the particular system to be very precisely matched to the actual air conditioning requirement of the conditioned space served by a particular system.
As previously mentioned, the coil depth D of each accordion-pleated coil fabricated from a selected number of the identically sized coil modules 32 may be easily made identical for each different capacity coil produced. This advantageously avoids the coil depth variation typically encountered when conventional A-coils are utilized. Accordingly, the coil housing length (in the air flow direction) necessary to accommodate each of the different capacity refrigerant coils of the present invention may be advantageously kept at a constant value regardless of which capacity air conditioning coil is installed on the furnace, air handler or heat pump.
The "face velocity" of an air conditioning coil is conventionally defined as the total volumetric air flow passing through the coil divided by the total effective upstream side surface area of the coil Thus, the face velocity of a coil having a 2.0 square foot face area across which a 1200 cubic feet/minute air flow occurs would be 600 feet/minute. For many years it has been thought necessary to size refrigerant coils (such as conventional A-coils) used in the indoor sections of air conditioning equipment in a manner such that the coil face velocity is maintained within the 300-500 feet/minute velocity range
Conventional coil design wisdom has been that a coil face velocity below about 300 feet/minute results in unacceptably low coil heat exchange efficiency, while a coil face velocity above about 500 feet/minute yields an unacceptable degree of condensate "blow through" and additionally raises the air pressure drop across the coil to an undesirable level.
Also in accordance with conventional coil design theory, the two refrigerant coil slabs used to define refrigerant A-coils are of a multi-row, multi-circuit construction for purposes of heat exchange efficiency. This multi-row/multicircuit configuration, coupled with the coil face area needed to keep the face velocity of the coil within the traditional 300-500 feet/minute range, typically results in an air pressure drop across the coil that, as a practical matter, precludes the use in the coil of "enhanced" fins (i.e., fins of, for example, a lanced or louvered construction designed to increase the air-to-fin heat exchange efficiency). Typically, the increased pressure drop associated with this type fin enhancement is unacceptable in conventional refrigerant A-coils. Accordingly, conventional A-coils are usually provided with unenhanced fins.
The present invention significantly departs from this conventional refrigerant coil design theory in several regards. For example, as previously mentioned, each of the identically sized coil modules 32 is of a single row, single refrigerant circuit design. Additionally, the face area of each coil module 32 is preferably sized so that the face velocity of each multimodule coil, during operation of the air conditioning unit in which it is installed, is below the conventional 300 feet/minute lower limit. Preferably, such face velocity is in the range of from about 100 feet/minute to about 200 feet/minute. This face velocity reduction desirably and quite substantially reduces the air pressure drop across the coil, thereby reducing the power requirements for the furnace blower. Specifically, the modular coils of the present invention are preferably designed to operate with air pressure drops of less than about 0.10".
In turn, this substantial air pressure drop reduction permits a closer fin spacing to be used in the coil modules 32, the module fin spacing preferably being in the range of from about 16 fins/inch to about 22 fins/inch (compared to the 10-14 fins/inch used in conventional A-coils). The lowered face velocity of the accordion-pleated refrigerant coils of the present invention also permits the fins 48 to be of an enhanced construction as illustrated in FIGS. 5 and 6. While a variety of fin enhancement designs could be used, a representative louvered fin enhancement design is illustrated in FIGS. 5 and 6, and comprises louvers 64 formed in the fins and extending at an angle relative to the fin bodies and positioned adjacent fin openings 66 resulting from the formation of the louvers 64. This fin enhancement desirably increases the air-to-fin heat exchange efficiency of the coil modules 32. In the illustrated preferred embodiment of the coil module 32, its tubes 40 are internally enhanced, preferably by the formation of a circumferentially spaced series of radial grooves 68 (FIG. 5A) formed in the interior side surface 70 of each tube and extending along its length. This internal tube enhancement desirably increases the tube-to-refrigerant heat exchange efficiency of each coil module 32.
While the accordion-pleated refrigerant coils of the present invention have been illustrated in conjunction with the evaporator section of a forced air furnace 10, it will readily be appreciated by those skilled in this art that the coils of the present invention could also be used in other air conditioning applications such as in heat pumps or other types of air conditioning apparatus. Additionally, downflow or horizontal flow units could also have the coils of the present invention incorporated therein.
The single row/single circuit configuration of each of the coil modules 32 serves to maximize the primary heat transfer performance (i.e., the tube-to-refrigerant heat transfer efficiency) of the accordion-pleated refrigerant coil by maintaining a generally optimum refrigerant flow per circuit. When smooth coil tubes are utilized, this permits the optimization of refrigerant pressure drop. When internally grooved or otherwise internally enhanced coil tubes are used, this allows for the optimization of refrigerant pressure drop with shorter length tubes.
The single row/single circuit design of the coil modules also permits the secondary heat transfer performance (i.e., the air-to-fin heat exchange efficiency) of the coil to be maximized by allowing the maintenance of an optimum cfm/ton air flow ratio. In turn, this provides the previously mentioned low air face velocity for the coils of the present invention which yields reduced air side pressure drops, reduces water blow-off potential, and maintains the latent capacity for the coil. With plain (i.e., unenhanced) fins, this permits a considerably higher fin density than is achievable with conventional evaporator coils. With enhanced fins and unenhanced coil tubes, this permits a low fin density. On the other hand, when enhanced, internally grooved coil tubes are used, this permits a considerably higher enhanced fin density to match the shorter overall tubing length requirements.
The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims. | Using a series of identically sized, single row, single circuit refrigerant coil modules, fin/tube refrigerant coils of different nominal air conditioning tonnages are constructed by arranging different numbers of the identically sized modules in accordion-pleated orientations, with each modular coil having the same depth in the direction of intended air flow across the coil. Compared to conventional "A" coils used on the indoor side of air conditioning circuits, these accordion-pleated modular coils are more compact in the air flow direction, provide more coil surface area, permit lower coil face velocities with higher fin density, and significantly reduce the overall coil manufacturing costs since only one size of coil slab needs to be fabricated and inventoried to later assemble refrigerant coils of widely varying nominal air conditioning tonnages. | 5 |
Continuation application of U.S. Ser. No. 10/893,386 filed on Jul. 19, 2004 now U.S. Pat. No. 6,846,059.
FIELD OF THE INVENTION
This invention relates to the field of ink jet printing systems, and more specifically to a printhead support assembly and ink supply arrangement for a printhead assembly and such printhead assemblies for ink jet printing systems.
DESCRIPTION OF THE PRIOR ART
Micro-electromechanical systems (“MEMS”), fabricated using standard VLSI semi-conductor chip fabrication techniques, are becoming increasingly popular as new applications are developed. Such devices are becoming widely used for sensing (for example accelerometers for automotive airbags), inkjet printing, micro-fluidics, and other applications. The use of semi-conductor fabrication techniques allows MEMS to be interfaced very readily with microelectronics. A broad survey of the field and of prior art in relation thereto is provided in an article entitled “The Broad Sweep of Integrated Micro-Systems”, by S. Tom Picraux and Paul McWhorter, in IEEE Spectrum, December 1998, pp 24–33.
In PCT Application No. PCT/AU98/00550, the entire contents of which is incorporated herein by reference, an inkjet printing device has been described which utilizes MEMS processing techniques in the construction of a thermal-bend-actuator-type device for the ejection of a fluid, such as an ink, from a nozzle chamber. Such ink ejector devices will be referred to hereinafter as MEMJETs. The technology described in the reference is intended as an alternative to existing technologies for inkjet printing, such as Thermal Ink Jet (TIJ) or “Bubble Jet” technology developed mainly by the manufacturers Canon and Hewlett Packard, and Piezoelectric Ink Jet (PIJ) devices, as used for example by the manufacturers Epson and Tektronix.
While TIJ and PIJ technologies have been developed to very high levels of performance since their introduction, MEMJET technology is able to offer significant advantages over these technologies. Potential advantages include higher speeds of operation and the ability to provide higher resolution than obtainable with other technologies. Similarly, MEMJET Technology provides the ability to manufacture monolithic printhead devices incorporating a large number of nozzles and of such size as to span all or a large part of a page (or other print surface), so that pagewidth printing can be achieved without any need to mechanically traverse a small printhead across the width of a page, as in typical existing inkjet printers.
It has been found difficult to manufacture a long TIJ printhead for full-pagewidth printing. This is mainly because of the high power consumption of TIJ devices and the problem associated therewith of providing an adequate power supply for the printhead. Similarly, waste heat removal from the printhead to prevent boiling of the ink provides a challenge to the layout of such printhead. Also, differential thermal expansion over the length of a long TIJ-printhead may lead to severe nozzle alignment difficulties.
Different problems have been found to attend the manufacture of long PIJ printheads for large- or full-page-width printing. These include acoustic crosstalk between nozzles due to similar time scales of drop ejection and reflection of acoustic pulses within the printhead. Further, silicon is not a piezoelectric material, and is very difficult to integrate with CMOS chips, so that separate external connections are required for every nozzle.
Accordingly, manufacturing costs are very high compared to technologies such as MEMJET in which a monolithic device may be fabricated using established techniques, yet incorporate very large numbers of individual nozzles. Reference should be made to the aforementioned PCT application for detailed information on the manufacture of MEMJET inkjet printhead chips; individual MEMJET printhead chips will here be referred to simply as printhead segments. A printhead assembly will usually incorporate a number of such printhead segments.
While MEMJET technology has the advantage of allowing the cost effective manufacture of long monolithic printheads, it has nevertheless been found desirable to use a number of individual printhead segments (CMOS chips) placed substantially end-to-end where large widths of printing are to be provided. This is because chip production yields decrease substantially as chip lengths increase, so that costs increase. Of course, some printing applications, such as plan printing and other commercial printing, require printing widths that are beyond the maximum length that is practical for successful printhead chip manufacture.
SUMMARY OF THE INVENTION
The present invention is broadly directed to the provision of a suitable printhead segment support structure and ink supply arrangement for an inkjet printhead assembly capable of single-pass, full-page-width printing as well as to such printhead assemblies. While the invention was conceived in the context of MEMJET printhead segments (chips), and thus the following summary and description of the invention is provided with particular reference to printhead assemblies incorporating MEMJET printhead segments, it is believed that the invention also has the potential to be employed with other ink jet printhead technologies.
Accordingly, it is one object of the present invention to provide a printhead segment support structure that is capable of accommodating a series of printhead segments as described in PCT/AU98/00550 in an array that permits single-pass pagewidth printing across the width of a surface passing under the printhead assembly.
The term “single-pass pagewidth printing” should here be understood as referring to a printing operation during which the printhead assembly is moved in only one direction along or across the entire width or length of any print surface, as compared to a superimposed, generally orthogonal printhead carriage movement as employed in conventional ink jet printers. (Of course, printhead assembly movement may be relative, with the surface moving past a stationary printhead assembly.) It will be also understood that there are many possible page widths and the inkjet printhead segment support structure of the invention would be suitable for adaptation to a range of widths. A printhead assembly in accordance with the invention should in particular be useful where a plurality of generally elongate, but relatively small printhead segments are to be used to print across substantially the entire width of a sizable surface without the need for mechanically moving the printhead assembly or any printhead segment across as well as along the print surface.
The invention has also been conceived in light of potential problems related to the relatively small size of individual printhead segments, their fragility and the required highly accurate alignment or registration of individual printhead segments with each other on the support structure and with external components in order to provide a printhead assembly capable of single-pass, full pagewidth printing. Multiple ink supply channels are required to supply ink in reliable manner to all printhead segments. Because of the small size of the segments, this in general would require high quality micro-machined parts. An ink supply conduit, on the other hand, is most economically made if it can be formed at a much coarser scale.
Accordingly, another object of the invention is to provide a printhead segment support structure with a print fluid supply arrangement that ensures adequate print fluid (e.g. ink) supply to individual printhead segments mounted to the support structure, at an affordable manufacturing cost.
Typical MEMJET printhead segments have a dimension of 2 cm length by 0.5 mm width, and will include (in a layout for 4-color printing) four lengthwise-oriented rows of ink ejection nozzles, the segment being of monolithic fabrication. Longer segments could be made and used, but the size mentioned gives very satisfactory fabrication yields. Each printhead segment has ink inlet holes arrayed on one surface and corresponding nozzle outlets arrayed on an opposite surface. Each of the four rows will then require connection to an appropriate ink supply, such that an inkjet printhead assembly can be provided for operation with (for example) cyan, magenta, yellow and black inks for color printing.
Accordingly, yet a further object is to provide an ink supply arrangement thereby to enable supply of a number of differently colored inks (or other printing fluids) to selected ink inlets of individual printhead segments carried on a support structure for full pagewidth color printing.
Another related object of the invention is to provide a print fluid supply arrangement that is simple in layout and thus easy to incorporate in a printhead support structure. It should ensure even and reliable distribution of print fluids in a pagewidth inkjet printhead assembly.
In a first aspect, the invention provides a support for a plurality of inkjet printhead segments, said support including:
a hollow elongate member having at least one ink supply channel formed therein, the, or each, ink supply channel being in fluid communication with an elongate slot in and extending at least partly along the elongate member; and
a plurality of printhead segment carriers received and secured in neighbouring arrangement within the slot, each printhead segment carrier being adapted for mounting thereto of at least one printhead segment.
Each printhead segment carrier may include at least one ink gallery that is in fluid communication with said, or an associated one of said, ink supply channels when mounted to that printhead segment carrier.
The printhead segment carriers may be configured so that when the printhead segments are mounted in the printhead segment carriers they define a series of printing ranges in a direction lengthwise along the elongate member that overlap to define a combined printing range of greater lengthwise extent than any of the printing ranges of the respective printhead segments.
The printhead segment carriers may be substantially identical to one another and may have stepped terminal ends thereby to enable neighbouring pairs of printhead carriers to be mounted within the slot in a staggered manner.
Each printhead segment carrier may have an elongate recess in an external surface of the carrier within which at least one printhead segment is mountable and wherein recesses of neighbouring pairs of carriers overlap in a direction along the elongate member.
Each printhead segment carrier may define an elongate ink delivery slot that opens into said recess of each printhead segment carrier. Each ink delivery slot may be in fluid communication with a respective ink supply channel via said ink gallery that extends from said at least one ink slot to an opening in a rear face of the printhead segment carrier.
A plurality of said ink galleries and said openings may be in fluid communication with the, or each, ink delivery slot. Said openings associated with the, or each, said ink delivery slot may be arranged in a row extending in a direction along the elongate member.
Each printhead segment carrier may have a plurality of ink supply channels and a plurality of said rows of openings. Each row of openings may be aligned along its length with one said ink channel for passage of ink from said ink channel through said row of openings.
The ink galleries may be defined by a plurality of parallel walls extending transversely in each printhead segment carrier and intersecting with a plurality of converging walls extending from the rear face to shaped inner edges that at least partially define the ink delivery slots.
The assembly may include a shim that is shaped to be received in the slot in the elongate member and to lie between the elongate member and said printhead segment carriers, said shim having at least one aperture therein to permit flow of ink between the or an associated one of said ink supply channels and a corresponding one ink gallery of the respective printhead segment carrier.
The shim and the slot may be substantially semi-circular in cross-sectional shape.
The shim and/or the elongate member may comprise means for snap-fittingly mounting said shim at said slot. In another example, the shim may be adhesively bonded to mating surfaces of the elongate member. In yet another example, the printhead segment carriers may be adhesively bonded to the shim.
Webs, which abut external surfaces of the elongate member, may be attached to edges extending in a direction along the shim.
Each printhead segment carrier may have a recess formed in an external surface thereof within which at least one printhead segment is received when mounted to the printhead segment carrier. Said external surface may have a second recess formed therein and adapted to receive at least a part of a power or signal conductor terminating on the or one said printhead segment mounted to the printhead segment carrier.
Said conductor may comprise a tape automated bonded (TAB) film.
Said tape automated bonded film (TAB) may be wrapped around an external surface of the elongate member and terminated on a printed circuit board secured to a side of the elongate member opposite to the printhead segment to which it is connected.
The support assembly may include a first cap secured to a first terminal end of the elongate member and may have an ink inlet port in fluid communication with the or an associated one of said ink supply channels.
The support assembly may further include a second cap secured to a second terminal end of the elongate member and having an opening for bleeding of air from the or an associated one of said ink supply channels. Means for sealing off said opening after such bleeding may be provided.
Said second cap may include an outer face with a tortuous channel formed therein. Said tortuous channel may be in fluid communication with said opening and said sealing means may include a film removable at least in part from the outer face and adapted to adhere to the outer face thereby to cover the tortuous channel and seal off the opening.
The support assembly may further include an external protective shield plate covering the printhead segment carriers and having openings arranged to permit unimpeded passage of ink ejected from nozzles of printhead segments mounted to the carriers towards a surface passing beneath the support assembly.
The elongate member may have three, four or six of said ink supply channels, one each for differently colored ink.
Each printhead segment carrier may be mounted within the slot at a longitudinal position within a predetermined distance of a designated longitudinal position of the carrier corresponding to a designated longitudinal position within the slot of a printhead segment when mounted to said printhead segment carrier.
The elongate member may be of substantially constant cross-sectional shape along its entire length.
In cross-section, the elongate member may include a peripheral structured wall including a base wall section, and side wall sections standing out from opposite edges of said base wall section, and wherein said slot lies between free edges of said side wall sections.
Said elongate member may further include at least one internal web extending from the base wall section and along said elongate member.
Said elongate member may have a plurality of said internal webs. In cross-section, said free edges of the side wall sections and free edges of said internal webs may lie on a semicircle and may define boundaries of said slot so that said slot is of semicircular cross-section.
In a second aspect, the invention provides an inkjet printhead assembly including:
a hollow elongate member having at least one ink supply channel formed therein, the or each ink supply channel being in fluid communication with an elongate slot in and extending at least partly along the elongate member; and
a plurality of printhead segment carriers received and secured in neighbouring arrangement within the slot; and
at least one printhead segment mounted to each printhead segment carrier.
Thus, the second aspect of the invention is directed to a printhead assembly that includes the support assembly of the first aspect of the invention.
It is preferred that the at least one printhead segment on each printhead segment carrier has a defined printing range in a direction lengthwise along the elongate member, and that the printing ranges of the printhead segments mounted to a plurality of adjoining printhead segment carriers overlap, so that the printhead segments mounted to said plurality of adjoining printhead segment carriers have a combined printing range of greater lengthwise extent than any of the printing ranges comprised therein. This is a suitable way in which printing may be accomplished on a surface without the presence of gaps corresponding to lengthwise gaps between individual printhead segments.
In a further aspect, the invention provides a method for assembling the inkjet printhead assembly wherein the step of mounting to each printhead segment carrier its respective at least one printhead segment precedes the step of securing that printhead segment carrier within the slot. It is then preferred that the printhead segment carriers are secured within the slot sequentially, and that the at least one printhead segment in each printhead segment carrier installed after the first is positioned longitudinally relative to the at least one printhead segment in the printhead segment carrier last installed before being finally secured and immobilized within the slot. Thus, accurate relative positioning of successive printhead segments lengthwise along the elongate member can be achieved.
Other aspects, objects and advantages of the invention, in its different embodiments, will also become apparent from the description given below of preferred embodiments and from the appended claims.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of one embodiment of an inkjet printhead assembly according to the invention;
FIG. 2 is a perspective view of the inkjet printhead assembly shown in FIG. 1 , with a cover component (shield plate) removed;
FIG. 3 is an exploded perspective view of a part only of the inkjet printhead assembly shown in FIG. 1 ;
FIG. 4 is a perspective partial view of a support extrusion forming part of the inkjet printhead assembly shown in FIG. 3 ;
FIG. 5 is a perspective view of a sealing shim forming part of the inkjet printhead assembly shown in FIG. 3 ;
FIG. 6 is a perspective view of a printhead segment carrier shown in FIG. 3 ;
FIG. 7 is a further perspective view of the printhead segment carrier shown in FIG. 6 ;
FIG. 8 is a bottom elevation of the printhead carrier shown in FIGS. 6 and 7 (as viewed in the direction of arrow “X” in FIG. 6 );
FIG. 9 is a top elevation of the printhead carrier shown in FIGS. 6 and 7 (as viewed in the direction of arrow “Y” in FIG. 6 );
FIG. 10 is a cross-sectional view of the printhead carrier of FIGS. 6 and 7 taken at station “B—B” in FIG. 8 ;
FIG. 11 is a cross-sectional view of the printhead carrier of FIGS. 6 and 7 taken at station “A—A” in FIG. 8 ;
FIG. 11 a is an enlarged cross-sectional view of the seating arrangement of a printhead segment at the print carrier as per detail “E” in FIG. 11 ;
FIG. 12 is a cross-sectional view of the printhead carrier of FIGS. 6 and 7 taken at station “D—D” in FIG. 8 ;
FIG. 13 is an external perspective view of an end cap of the inkjet printhead assembly shown in FIG. 1 ;
FIG. 14 is an internal perspective view of the end cap shown in FIG. 13
FIG. 15 is an external perspective view of a further end cap of the inkjet printhead assembly shown in FIG. 1 ;
FIG. 16 is an internal perspective view of the end cap shown in FIG. 15 ;
FIG. 17 is a perspective view (from the bottom) of the printhead assembly shown in FIG. 1 ;
FIG. 18 is a perspective view of a part assembly of a support profile and modified sealing shim which are alternatives to those shown in FIGS. 4 and 5 ;
FIG. 19 is a perspective view showing a molding tool and illustrating the basic arrangement of die components for injection molding of the printhead carrier shown in FIGS. 6 and 7 ;
FIG. 20 is a schematic cross-section of the injection molding tool shown in FIG. 19 , in an open position; and
FIG. 21 is a schematic transverse cross-section of the injection-molding tool shown in FIG. 19 , in a closed position, taken at a station corresponding to the station “A—A” in FIG. 8 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows in perspective view an inkjet printhead assembly 1 according to one aspect of the invention and, in phantom outline, a surface 2 on which printing is to be affected. In use, the surface 2 moves relative to the assembly 1 in a direction indicated by arrow 3 and transverse to the main extension of assembly 1 (this direction is hereinafter also referred to as the transverse direction of the assembly 1 ), so that elongate printhead segments 4 , in particular MEMJET printhead segments such as described in the above-mentioned PCT/AU98/00550, placed in stepped overlapping sequence along the lengthwise extension of assembly 1 can print simultaneously across substantially the entire width of the surface. The assembly 1 includes a shield plate 5 with which the surface 2 may come into sliding contact during such printing. Shield plate 5 has slots 6 , each corresponding to one of the printhead segments 4 , and through which ink ejected by that printhead segment 4 can reach surface 2 .
The particular assembly 1 shown in FIG. 1 has eleven printhead segments 4 , each capable of printing along a 2 cm printing length (or, in other words, within a printing range extending 2 cm) in a direction parallel to arrow 7 (hereinafter also called the lengthwise direction of the assembly 1 ) and is suitable for single-pass printing of a portrait A4-letter size page. However, this number of printhead segments 4 and their length are in no way limiting, the invention being applicable to printhead assemblies of varying lengths and incorporating other required numbers of printhead segments 4 .
The slots 6 and the printhead segments 4 are arranged along two parallel lines in the lengthwise direction, with the printing length of each segment 4 (other than the endmost segments 4 ) slightly overlapping that of its two neighboring segments 4 in the other line. The printing length of each of the two endmost segments 4 overlaps the printing length of its nearest neighbor in the other row at one end only. Thus printing across the surface 2 is possible without gaps in the lengthwise direction of the assembly. In the particular assembly shown, the overlap is approximately 1 mm at each end of the 2 cm printing length, but this figure is by no means limiting.
FIG. 2 shows assembly 1 with the shield plate 5 removed. Each printhead segment 4 is secured to an associated one printhead segment carrier 8 that will be described below in more detail. Also secured to each printhead segment 4 is a tape automated bonded (TAB) film 9 , which carries signal and power connections (not individually shown) to the associated printhead segment 4 . Each TAB film 9 is closely wrapped around an extruded support profile 10 (whose function will be explained below) that houses and supports carriers 8 , and they each terminate onto a printed circuit board (PCB) 11 secured to the profile 10 on a side thereof opposite to that where the printhead segments 4 are mounted, see also FIG. 3 .
FIG. 3 shows an exploded perspective view of a part only of assembly 1 . In this view, three only of the printhead segment carriers 8 are shown numbered 8 a , 8 b and 8 c , and only the printhead segment 4 associated with printhead segment carrier 8 a is shown and numbered 4 a . The TAB film 9 associated therewith is terminated at one end on an outer face of the printhead segment 4 and is otherwise shown (for clarity purposes) in the unwound, flat state it has before being wound around profile 10 and connected to PCB 11 . As can be seen in FIG. 3 , printhead segment carriers 8 are received (and secured), together with an interposed sealing shim 25 , in a slot 21 of half-circular cross-sectional shape in profile member 10 as will be explained in more detail below.
FIG. 4 illustrates a cross-section of the profile member 10 (which is preferably an aluminum alloy extrusion). This component serves as a frame and/or support structure for the printhead segment carriers 8 (with their associated printhead segments 4 and TAB films 9 ), the PCB 11 and shield plate 5 . It also serves as an integral ink supply arrangement for the printhead segments 4 , as will become clearer later.
Profile member 10 is of semi-open cross-section, with a peripheral, structured wall 12 of uniform thickness. Free, opposing, lengthwise running edges 16 ′, 17 ′ of side wall sections 16 and 17 respectively of wall 12 border or delineate a gap 13 in wall 12 extending along the entire length of profile member 10 . Profile member 10 has three internal webs 14 a , 14 b , 14 c that stand out from a base wall section 15 of peripheral wall 12 into the interior of member 10 , so as to define together with side wall sections 16 and 17 a total of four (4) ink supply channels 20 a , 20 b , 20 c and 20 d which are open towards the gap 13 . The shapes, proportions and relative arrangement of the webs and wall sections 14 a–c , 16 , 17 are such that their respective free edges 14 a ′, 14 b ′, 14 c ′ and 16 ′, 17 ′, as viewed in the lengthwise direction and cross-section of profile member 10 , define points on a semi-circle (indicated by a dotted line at “a” in FIG. 4 ). In other words, an open slot 21 of semicircular cross-sectional shape is defined along one side of profile member 10 that runs along its extension, with each of the ink supply channels 20 a–d opening into common slot 21 .
Base wall section 15 of profile member 10 also includes a serrated channel 22 opening towards the exterior of member 10 , which, as best seen in FIG. 3 , serves to receive fastening screws 23 to fixedly secure PCB 11 onto profile member 10 in a form-fitting manner between free edges 24 (see FIG. 4 ) of longitudinally extending curved webs 107 extending from the base wall section 15 of profile member 10 .
Referring again to FIG. 3 , sealing shim 25 is received (and secured) within the half-circular open slot 21 . As best seen in FIGS. 3 and 5 , shim 25 includes four lengthwise extending rows of rectangular openings 26 that are equidistantly spaced in peripheral (widthwise) direction of shim 25 , so that three lengthwise-extending web sections 27 between the aperture rows (of which two are visible in FIG. 5 ) are located so as to be brought into abutting engagement against the free edges 14 a ′, 14 b ′ and 14 c ′ of webs 14 a , 14 b , 14 c of profile member 10 when shim 25 is received in slot 21 . As can be gleaned from FIG. 4 , the free edges 16 ′ and 17 ′ of side wall sections 16 , 17 of profile member 10 are shaped such as to provide a form-lock for retaining the lengthwise extending edges 28 of shim member 25 as a snap fit. In other words, once shim 25 is mounted in profile member 10 , it provides a perforated bottom for slot 21 , which allows passage of inks from the ink supply channels 20 a–d through apertures 26 in shim 25 into slot 21 . A glue or sealant is provided where shim webs 27 and edges 28 mate with the free edges 14 a ′, 14 b ′, 14 c ′, 16 ′ and 17 ′ of profile member 10 , thereby preventing cross-leakage between ink supply channels 20 a–d along the abutting interfaces between shim 25 and profile member 10 . It will be noted from FIG. 5 that not all apertures 26 have the same opening size. Reference numerals 26 ′ indicate two such smaller apertures, the significance of which is described below, which are present in each aperture row at predetermined aperture intervals. A typical size for the full-sized apertures 26 is 2 mm×2 mm. The shim is preferably of stainless steel, but a plastics sheet material may also be used.
Turning next to FIGS. 6–12 , these illustrate in different views and sections a typical printhead segment carrier 8 . Carrier 8 is preferably a single microinjection molded part made of a suitable temperature and abrasion resistant and form-holding plastics material. (A further manufacturing operation is carried out subsequent to molding, as described below.) As best seen in FIGS. 6 and 7 , the overall external shape of carrier 8 can be described illustratively as a diametrically slit half cylinder, with a half-circular back face 91 , a partly planar front face 82 and stepped end faces 83 . FIG. 8 shows a plan view of back face 91 and FIG. 9 shows a plan view of front face 82 .
Carrier 8 has a plane of symmetry halfway along, and perpendicular to, its length, that is, as indicated by lines marked “b” in FIGS. 8 and 10 which lie in the plane. Line “b” as shown in FIG. 8 extends in a direction that will hereinafter be described as transverse to the carrier 8 . (When the carrier 8 is installed in the assembly 1 , this direction is the same as the transverse direction of the assembly 1 .) Lines marked “c” in FIGS. 8 , 9 , 11 and 12 together similarly indicate the position of an imaginary plane which lies between two sections of the carrier 8 of different length and whose overall cross-sectional shapes are quarter circles. Line “c” as shown in FIG. 9 extends in a direction that will hereinafter be described as lengthwise in the carrier 8 . (When the carrier 8 is installed in the assembly 1 this direction is the same as the lengthwise direction of the assembly 1 .) These sections will hereinafter be referred to as the shorter and longer “quarter cylinder” sections 8 ′ and 8 ″, respectively, to allow referenced description of features of the carrier 8 .
Each stepped end face 83 includes respective outer faces 84 ′ and 85 ′ of quarter-circular-sector shaped end walls 84 and 85 and an outer face 86 ′ of an intermediate step wall 86 between and perpendicular to end walls 84 , 85 . This configuration enables carriers 8 to be placed in the slot 21 of profile 10 in such a way that adjoining carriers 8 overlap in the lengthwise direction with the step walls 86 of pairs of neighbouring carriers 8 facing each and overlapping. Such an “interlocking” arrangement is shown in FIG. 2 , wherein it is apparent that every one of the eleven (11) carriers 8 has an orientation, relative to its neighbouring carrier or carriers 8 , such that faces 84 ′ and 85 ′ of each carrier lie adjacent to faces 85 ′ and 84 ′, respectively, of its neighbouring carrier(s) 8 . In other words, each carrier 8 is so oriented in relation to its neighbouring carrier(s) as to be rotated relatively by 180° about an axis perpendicular to the face 82 . In essence, neighbouring carriers 8 will align along a common lengthwise-oriented plane defined between the step walls 86 of adjoining carriers 8 , shorter and longer quarter cylinder sections 8 ′ and 8 ″ of adjoining carriers 8 alternating with one another along the extension of slot 21 .
Turning now in particular to FIGS. 7 , 9 , 11 and 11 a , front face 82 of carrier 8 includes on the shorter quarter cylinder section 8 ′ a planar surface 81 . Formed in surface 81 are two handling (i.e. pick-up) slots 87 whose purpose is described below. On the longer quarter cylinder section 8 ″, front face 82 incorporates a mounting or support surface 88 recessed with respect to edges 89 of sector-shaped end walls 84 that are co-planar with the surface 81 . As best seen in FIG. 11 , mounting surface 88 recedes in slanting fashion from a point on the back face 91 of the longer quarter cylinder section 8 ″ towards an elongate recess 90 extending lengthwise between walls 84 . Recess 90 is of constant transverse cross-section along its length and is shaped to receive in form-fitting manner one printhead segment 4 . FIG. 11 a shows, schematically only, printhead segment 4 in position in recess 90 . Mounting surface 88 is provided to accommodate in flush manner with respect to the surface 81 the terminal end of TAB film 9 connected to printhead segment 4 , as is best seen in FIG. 3 . Due to the opposing orientations of neighbouring carriers 8 along the extension of assembly 1 , the TAB films 9 associated with any two neighbouring carriers 8 lead away from their respective segments 4 in opposite transverse directions, as can be seen in FIG. 2 .
Referring now to FIGS. 6 , 7 , 8 , 10 and 11 in particular, four rows of ink galleries or ink supply passages 92 a to 92 d of generally quadrilateral cross-section are formed within the printhead segment carrier 8 . The ink galleries 92 a to 92 d act as conduits for ink to pass from the ink supply passages 20 a to 20 d , respectively, via openings 26 in the shim 25 , to the printhead segment 4 mounted in recess 90 of the printhead segment carrier 8 . Galleries 92 a – 92 d extend in quasi-radial arrangement between the half-cylindrical back face 91 of carrier 8 and recess 90 located in the longer quarter cylinder section 8 ″ at front face 82 . The expression “quasi-radial” is used here because recess 90 is not located at a transversely central position across carrier 8 , but is offset into the longer quarter cylinder section 8 ″, so that the inner ends of galleries 92 a – 92 d are similarly off-set, as further described below. Each gallery 92 has a rectangular opening 93 at back face 91 . All rectangular openings 93 have the same dimension in a peripheral direction of face 91 and are equidistantly spaced around the periphery of back face 91 . Moreover, the openings 93 are symmetrically located on opposing sides of the boundary between shorter quarter cylinder section 8 ′ and longer quarter cylinder section 8 ″, as represented in FIG. 11 by the line marked “c”. All openings 93 in the shorter quarter cylinder section 8 ′ are of the same dimension, and equispaced, in the lengthwise direction. This also applies to the openings 93 in the longer quarter cylinder section 8 ″, except that openings 93 ′ in the longer quarter cylinder section 8 ″ which correspond to endmost galleries 92 a ′ and 92 b ′ are of smaller dimension in the lengthwise direction than the other galleries 92 a and 92 b , respectively.
By way of further description of how the galleries 92 a to 92 d are formed, printhead segment carrier 8 includes a set of five (5) quasi-radially converging walls 95 which converge from back face 91 towards recess 90 at front face 82 and two of which define the faces 81 and 88 . The walls 95 perpendicularly intersect seven (7) generally semi-circular and mutually parallel walls 97 that are equidistantly spaced apart in lengthwise extension of carrier 8 . Of walls 97 , the two endmost ones extending into the shorter quarter cylinder section 8 ′ provide the endwalls 85 of stepped end faces 83 , thereby defining twenty-four (24) quasi-radially extending ink galleries 92 a to 92 d , of quadrilateral cross-section, in four lengthwise-extending rows each of six galleries. The walls 97 are parallel to and lie between endwalls 84 .
FIG. 12 shows a cross-section through one of the lengthwise end portions of longer quarter cylinder section 8 ″ of carrier 8 . By comparison with FIG. 11 (which shows a cross-section through the main body of carrier 8 ), it will be seen that the quasi-radially extending walls 95 bordering end gallery 92 a ′ have the same shape as walls 95 which border galleries 92 a , whereas gallery 92 b ′ is bounded on one side by intermediate step wall 86 and by a wall 108 . FIG. 12 also shows a wall 111 and a wall formation 112 on the wall 86 , the purpose of which is explained below.
Converging walls 95 are so shaped at their radially inner ends as to define four ink delivery slots 96 a to 96 d which extend lengthwise in the carrier 8 and which open into the recess 90 , as best seen in FIGS. 11 and 11 a . The slots 96 a to 96 d extend between the opposite end walls 84 of longer quarter cylinder section 8 ″ and pierce through the inner parallel walls 97 , including the endwise opposite walls 97 which form the end walls 85 of the shorter cylinder section 8 ′. FIG. 12 shows how slots 96 a to 96 d extend and are formed within the end portions of the longer quarter cylinder section 8 ″, where the slots 96 a to 96 d are defined by the terminal ends of two of walls 95 , walls 108 , 111 and wall formation 112 , wall formation 112 in effect being a perpendicular lip of intermediate step wall 86 .
The widths and transverse positioning of the ink delivery slots 96 a to 96 d are such that when a printhead segment 4 is received in recess 90 , a respective one of the slots 96 a – 96 d will be in fluid communication with one only of four lengthwise oriented rows of ink supply holes 41 on rear face 42 of printhead segment 4 , compare FIG. 11 a . Each row of ink supply holes 41 corresponds to a row of printhead nozzles 43 running lengthwise along the front face 44 of printhead segment 4 . In the schematic representation of segment 4 in FIG. 11 a , the positions of holes 41 and nozzles are indicated by dots, with no attempt made to show their actual construction. Reference to PCT Application No. PCT/AU98/00550 will provide further details of the make-up of segment 4 . Accordingly, each of the ink galleries of a specific gallery row 92 a to 92 d is in fluid communication with one only of the rows of ink supply holes 41 . Once a printhead segment 4 is form fittingly received in recess 90 and sealingly secured with its rear face 42 against the terminal inner ends of walls 95 , and wall formations 108 , 111 and 112 (using a suitable sealant or adhesive), cross-communication and ink bleeding between slots 96 a – 96 d via recess 90 is not possible.
When a carrier 8 is installed in its correct position lengthwise in the slot 21 of profile 10 , compare FIG. 3 , each opening 93 in its back face 91 aligns with one of the openings 26 in the shim 25 . Smaller openings 26 ′ in the shim 25 correspond to openings 93 ′ of the smaller galleries 92 a ′ and 92 b ′ of carrier 8 . Therefore, each one of the ink supply channels 20 a to 20 d is in fluid communication with one only of the rows of ink galleries 92 a to 92 d , respectively, and so with one only of the slots 96 a to 96 d respectively and only one of the rows of ink supply holes 41 . A suitable glue or sealant is provided at mating surfaces of the shim 25 and the carrier 8 to prevent leakage of ink from any of the channels 20 a to 20 d to an incorrect one of the galleries 92 , as described further below. The symmetrical location (mentioned above) of openings 93 on back face 91 of carrier 8 , which is matched by the openings 26 in shim 25 , enables the carrier 8 to be received in the slot 21 in either of the two orientations shown in FIG. 3 , with in both cases each row of ink galleries 92 a to 92 d aligning with one only of the ink supply channels 20 a to 20 d.
As mentioned above, the longer quarter cylinder section 8 ″ of carrier 8 has two galleries 92 a ′ and 92 b ′ at each lengthwise end that have no counterpart in the shorter section 8 ′. These galleries 92 a ′ and 92 b ′ provide direct ink supply paths to that part of their associated ink delivery slots 96 a and 96 b located in the longer quarter cylinder section 8 ″, and thus to the ink supply holes 41 of the printhead segment 4 that are located near the lengthwise terminal ends of segment 4 when secured within recess 90 . There are no corresponding quasi-radial galleries to supply ink to the end regions of the slots 96 c and 96 d . However, it is desirable to provide direct ink supply to the end portions of the other two slots 96 c and 96 d as well, without reliance on lengthwise flow within the slots 96 c and 96 d of ink that has passed through galleries 92 c and 92 d respectively. This is ensured by provision of ink supply chambers 99 c and 99 d which are shown in FIG. 12 and which supply ink to the slots 96 c and 96 d , respectively. Chambers 99 c and 99 d are bounded by the walls 84 , 86 , and wall formations 108 , 111 and 112 , are open towards slots 96 c and 96 d , respectively, and are in fluid communication through holes 113 and 114 in an endmost wall 97 with endmost ones of ink galleries 92 c and 92 d , respectively. The holes 113 and 114 have outlines shaped to match the transverse cross-sectional shapes of the chambers 99 c and 99 d , respectively, as shown in FIG. 12 , and the means whereby holes 113 and 114 are formed is described below.
FIGS. 13 and 14 show a first end cap 50 , which is sealingly secured to an open terminal longitudinal end of profile member 10 , as may be seen in FIGS. 1 and 2 . Cap 50 is molded from a plastics material and it incorporates a generally planar wall portion 51 that extends perpendicularly to a lengthwise axis of profile member 10 . Four tubular stubs 55 a – 55 d are integrally molded with planar wall portion 51 on side 52 of wall portion 51 which will face away from support profile 10 when end cap 50 is secured thereto. On the planar wall side 53 which will face the longitudinal terminal end of support profile 10 (see FIG. 14 ), four hollow-shaped stubs 57 a – 57 d are integrally molded with planar wall portion 51 . As best seen in FIG. 14 , ink supply conduits 56 a to 56 d are defined within tubular stubs 55 a to 55 d respectively, extend through planar wall portion 51 , and open within shaped stubs 57 a to 57 d , respectively, located on the other sides of cap 50 .
The shape of each one of the insert stubs 57 a to 57 d , as seen in transverse cross-section, corresponds respectively to one of the ink supply channels 20 a to 20 d of support profile so that, when cap 50 is secured to the terminal axial end of support profile 10 , the walls of stubs 57 a – 57 d are received form-fittingly in ink supply channels 20 a – 20 d to prevent cross-migration of ink therebetween. The face 53 abuts a terminal end face of the profile 10 . Preferably, glue or a sealant can be applied to the mating surfaces of profile 10 and cap 50 to enhance the sealing function.
The tubular stubs 55 a – 55 d serve as female connectors for pliable/flexible ink supply hoses (not illustrated) that can be connected thereto sealingly, thereby to supply ink to the integral ink supply channels 20 a – 20 d of support profile 10 .
A further stub 58 , D-shaped in transverse cross-section, is integrally molded to planar wall portion 51 at side 53 . In completed assembly 1 , the curved wall 71 , semi-circular in transverse cross-section, of retaining stub 58 seals against the inside surface of shim 25 , with the terminal edge of shim 25 abutting a peripheral ridge 72 around the stub 58 . Preferably, to avoid cross-migration of ink among channels 20 a to 20 d , an adhesive or sealant is provided between the shim 25 and wall 71 . The stub 58 assists in retaining the shim 25 in slot 21 .
A second end cap 60 , which is shown in FIGS. 15 and 16 , is mounted to the other end of the profile 10 opposite to cap 50 . Cap 60 has insert stubs 67 a to 67 d and a retaining stub 68 identical in arrangement and shape to stubs 57 a to 57 d and stub 58 , respectively, of end cap 50 . Insert stubs 67 a to 67 d and retention stub 68 are integrally molded with a planar wall portion 61 , and in the completed assembly 1 seal off the individual ink supply channels 20 a – 20 d from one another, to prevent cross-migration of ink among them. Wall 77 of the retention stub 68 abuts the shim 25 in the same way as described above. A sealant or adhesive is preferably used with end cap 60 in the same way (and for the same purpose) as described above in respect of end cap 50 .
Whereas end cap 50 enables connection of ink supply hoses to the printhead assembly 1 , end cap 60 has no tubular stubs on exterior face 62 of planar wall portion 61 . Instead, four tortuous grooves 65 a to 65 d are formed on exterior face 62 , and terminate at holes 66 a to 66 d , respectively, extending through wall portion 61 . Each one of holes 66 a to 66 d opens into a respective one of the channels 20 a to 20 d so that when the cap 60 is in place on the profile 10 , each one of the grooves 65 a to 65 d is in fluid communication with a respective one of the channels 20 a to 20 d . The grooves 65 a – 65 d permit bleeding-off of air during priming of the printhead assembly 1 with ink, as holes 66 a – 66 d permit air expulsion from the ink supply channels 20 a – 20 d of support profile 10 via grooves 65 a – 65 d . Grooves 65 a – 65 d are capped under a translucent plastic film 69 bonded to outer face 62 . Translucent plastic film 69 thus also serves the purpose of allowing visual confirmation that the ink supply channels 20 a – 20 d of profile 10 are properly primed. For charging the ink supply channels 20 a – 20 d with ink, film 69 is folded back (as shown in FIG. 15 ) to partially uncover grooves 65 a – 65 d , so that displaced air may bleed out as ink enters the grooves 65 a – 65 d through holes 66 a – 66 d . When ink is visible behind film 69 in each groove 65 a – 65 d , film 69 is folded towards face 62 and bonded against face 62 to sealingly cover face 62 and so cap-off grooves 65 a – 65 d and isolate them from one another.
Referring to FIG. 17 (and see also FIGS. 3 and 4 ), the printed circuit board (PCB) 11 locates between edges 24 formed on profile 10 , and is secured by screw fasteners 23 which engage with the serrations in elongate channel 22 of support profile 10 . The PCB 11 contains three surface mounted halftoning chips 73 , a data connector 74 , printhead power and ground busbars 75 and decoupling capacitors 76 . Side walls 16 , 17 of support profile 10 are rounded near the edges 24 to avoid damage to the TAB films 9 when these are wound about profile 10 . The electronic components 73 and 76 are specific to the use of MEMJET chips as the printhead segments 4 , and would of course, if other another printhead technology were to be used, be substituted with other components as necessitated by that technology.
The shield plate 5 illustrated in FIG. 1 , which is a thin sheet of stainless steel, is bonded with sealant such as a silicon sealant onto the printhead segment carriers 8 . The shield plate 5 shields the TAB films 9 and the printhead segments 4 from physical damage and also serves to provide an airtight seal around the printhead segments 4 when the assembly 1 is capped during idle periods.
The multi-part layout of the printhead assembly 1 that has been described in detail above has the advantage that the printhead segment carriers 8 , which interface directly with the printhead segments 4 and which must therefore be manufactured with very small tolerances, are separate from other parts, including particularly the main support frame (profile 10 ) which may therefore be less tightly toleranced. As noted above, the printhead segment carriers 8 are precision injection micro-moldings. Moldings of the required size and complexity are obtainable using existing micromolding technology and plastics materials such as ABS, for example. Tolerances of +/−10 microns on specified dimensions are achievable including the ink supply grooves 96 a – 96 d , and their relative location with respect to the recess 90 in which the printhead segments 4 are received. Such tolerances are suitable for this application. Other material selection criteria are thermal stability and compatibility with other materials to be used in the assembly 1 , such as inks and sealants. The profile 10 is preferably an aluminum alloy extrusion. Tolerances specified at +/−100 microns have been found suitable for such extrusions, and are achievable as well.
FIGS. 19 , 20 and 21 are schematic representations only, intended to provide an understanding of the construction of an injection-molding die used in the manufacture of a printhead segment carrier 8 . A multi-part die 100 is used, having a fixed base die part 104 , which in use defines the face 82 , recess 90 and slots 96 a to 96 d of the carrier 8 , and a multi-part upper die part 102 . The upper die part 102 is closed against the base part 104 for molding, and includes a part 101 with multiple fingers 101 a , which in use form the galleries 92 b (including galleries 92 b ′) and parts 106 which are fixed relative to part 101 . Also included in the upper part 102 are die parts 103 which are movable relative to the part 101 and which have fingers 103 a to form the remaining galleries 92 a , 92 c and 92 d . Parts 103 seat against parts 106 when molding is underway. Spaces between the fingers 101 a and 103 a correspond to the walls 97 . In use of the die 100 , terminal tips of the fingers 101 a and 103 a close against blades 105 which in use form the ink supply slots 96 a – 96 d of carrier 8 and which are mounted to male base 104 to be detachable and replaceable when necessary. Base die part 104 also has inserts 104 a , which in use form the pickup slots 87 . Because zero draft is preferred on the stepped end faces 83 in this application, the die 100 also has two movable end pieces (not shown, for clarity) which in use of the die 100 are movable generally axially to close against the upper die part 102 and which are shaped to define the end faces 84 ′, 85 ′ and 86 ′ of carrier 8 . FIG. 21 shows a schematic transverse cross-section of the mold 100 when closed, with areas in black corresponding to the carrier 8 being molded.
As was mentioned above, the two opposite end portions of the larger quarter cylinder section of carrier 8 incorporate two ink supply chambers 99 c and 99 d (see FIG. 12 ) to provide ink to the ink supply slots 96 c and 96 d in that region of the carrier 8 . These chambers 99 c and 99 d and associated communication holes 113 and 114 in parallel walls 97 that lead into the neighbouring galleries 92 c and 92 d , are formed in an operation subsequent to molding, by laser cutting openings of the required shape in the end walls 84 and the neighbouring inner parallel walls 97 from each end. The openings cut in end walls 84 are only necessary so as to access the inner walls 97 , and are therefore subsequently permanently plugged using appropriately shaped plugs 115 as shown in FIG. 6 .
Extrusions usable for profile 10 can be produced in continuous lengths and precision cut to the length required. The particular support profile 10 illustrated is 15.4 mm×25.4 mm in section and about 240 mm in length. These dimensions, together with the layout and arrangement of the walls 16 and 17 and internal webs 14 a to 14 c , have been found suitable to ensure adequate ink supply to eleven (11) MEMJET printhead segments 4 carried in the support profile to achieve four-color printing at 120 pages per minute (ppm). Support profiles with larger cross-sectional dimensions can be employed for very long printhead assemblies and/or for extremely high-speed printing where greater volumes of ink are required. Longer support profiles may of course be used, but are likely to require cross-bracing and location into a more rigid chassis to avoid alignment problems of individual printhead segments, for example in the case of a wide format printer of 54″(1372 mm) or more.
An important step in manufacturing (and assembling) the assembly 1 is achieving the necessary, very high level of precision in relative positioning of the printhead segments 4 , and here too the construction of the assembly 1 as described above is advantageous. A suitable manufacturing sequence that ensures such high relative positioning of printheads on the support profile will now be described.
After manufacture and successful testing of an individual printhead segment 4 , its associated TAB film 9 is bumped and then bonded to bond pads along an edge of the printhead segment 4 . That is, the TAB film is physically secured to segment 4 and the necessary electrical connections are made. The terms “bumped” and “bonded” will be familiar to persons skilled in the arts where TAB films are used. The printhead carrier 8 is then primed with adhesive on all those surfaces facing into recess 90 that mate and must seal with the printhead segment 4 , see FIG. 11 a , i.e. along the length of the radially-inner edges of walls 95 , 108 and 111 , the face of formation 112 and on inner faces of walls 84 . The printhead segment 4 is then secured in place in recess 90 with its TAB film 9 attached. Extremely accurate alignment of the printhead segment 4 within recess 90 of printhead segment carrier 8 is not necessarily required (but is preferred), because relative alignment of all segments 4 at the support profile 10 is carried out later, as is described below. The assembly of the printhead segment 4 , printhead segment carrier 8 and TAB film 9 is preferably tested at this point for correct operation using ink or water, before being positioned for placement in the slot 21 of support profile 10 .
The support profile 10 is accurately cut to length (where it has been manufactured in a length longer than that required, for example by extrusion), faced and cleaned to enable good mating with the end caps 50 and 60 .
A glue wheel is run the entire length of semi-circular slot 21 , priming the terminal edges 14 a ′, 14 b ′, 14 c ′ of webs 14 a – 14 c and edges 16 ′, 17 ′ of profile side walls 16 , 17 with adhesive that will bond the sealing shim 25 into place in slot 21 once sealing shim 25 is placed into it with preset distance from its terminal ends (+/−10 microns). The shim 25 is snap-fitted into place at edges 16 ′, 17 ′ and the glue is allowed to set. Next, end caps 50 and 60 are bonded into place whereby (ink channel sealing) insert stubs 57 a – 57 d and 67 a – 67 d are received in ink channels 20 a – 20 d of profile 10 , and faces 71 and 77 of retention stubs 58 and 68 , respectively, lie on shim 25 . This sub-assembly provides a chassis in which to successively place, align and secure further sub-assemblies (hereinafter called “carrier subassemblies”) each consisting of a printhead segment carrier 8 with its respective printhead segment 4 and TAB film 9 already secured in place thereon.
A first carrier sub-assembly is primed with glue on the back face 91 of its printhead segment carrier 8 . At least the edges of walls 95 and 86 are primed. A glue wheel, running lengthwise, is preferably used in this operation. After priming with glue, the carrier sub-assembly is picked up by a manipulator arm engaging into pick-up slots 87 on front face 82 of carrier 8 and placed next to the stub 58 of end cap 50 (or the stub 68 of cap 60 ) at one end of slot 21 in profile 10 . The glue employed is of slow-setting or heat-activatable type, thereby to allow a small level of positional manipulation of each carrier subassembly, lengthwise in the slot 21 , before final setting of the glue. With the first carrier subassembly finally secured to the shim 25 within the slot 21 , a second carrier sub-assembly is then picked up, primed with glue as above, and placed in a 180-degree-rotated position (as described above, and as may be seen in FIG. 3 ) next to the first carrier sub-assembly onto shim 25 and within the slot 21 . The second carrier sub-assembly is then positioned lengthwise so that there is correct lengthwise relative positioning of its printhead segment 4 and the segment 4 of the previously placed segment 4 , as determined using suitable fiducial marks (not shown) on the exposed front surface 44 of each of the printhead segments 4 . That is, lengthwise alignment is carried out between successive printhead segments 4 , even though it is the printhead segment carrier 8 that is actually manipulated. This relative alignment is carried out to such (sub-micron) accuracy as is required to match the printing resolution capability of the printhead segments 4 . Finally, the bonding of the second carrier sub-assembly to shim 25 is completed. The above process is then repeated with further carrier sub-assemblies being successively positioned, aligned, and bonded into place, until all carrier subassemblies are in position within the slot 21 and bonded in their correct positions.
The shield plate 5 has a thin film of silicon sealant applied to its underside and is mated to the printhead segment carriers 8 and TAB films 9 along the entire length of the printhead assembly 1 . By suitable choice of adhesive properties of the silicon sealant, the shield plate 5 can be made removable to enable access to the printhead segment carriers 8 , printhead segments 4 and TAB films 9 for servicing and/or exchange.
A sub-assembly of PCB 11 and printhead control and ancillary components 73 to 76 is secured to profile 10 using four screws 23 . The TAB films 9 are wrapped around the exterior walls 16 , 17 of profile 10 and are bumped and bonded (i.e. physically and electrically connected) to the PCB 11 . See FIG. 17 .
Finally, the completed assembly 1 is connected at the ink inlet stubs 55 a–d of end cap 50 to suitable ink supplies, primed as described above and sealed using sealing film 69 of end cap 60 . Power and signal connections are completed and the inkjet printhead assembly 1 is ready for final testing and subsequent use.
It will be apparent to persons skilled in the art that many variations of the above-described assembly and components are possible. For example, FIG. 18 shows a shim 125 that is substantially the same as shim 25 , including having openings 126 and 126 ′ corresponding to the openings 26 and 26 ′ in shim 25 , save for longitudinally extending rim webs 128 which, when the shim 125 is mounted to a support profile 110 , abut in surface-engaging manner against the outside of the terminal ends of side walls 116 , 117 of profile 110 instead of being snap-fittingly received between them as is the case with shim 25 . This arrangement permits wider tolerances to be used in the manufacture of the support profile 110 without compromising the mating capability of the shim 125 and the profile 110 .
In yet another possible arrangement, the shim 25 could be eliminated entirely, with the printhead segment carriers 8 then bearing and sealing directly on the edges 14 a ′– 14 c ′ and 16 ′, 17 ′ of the webs 14 a – 14 c and side walls 16 , 17 at slot 21 of support profile 10 .
It will be appreciated by persons skilled in the art that still further variations and modifications may be made without departing from the scope of the invention. The embodiments of the present invention as described above are in no sense intended to be restrictive. | A method of assembling an inkjet printhead commences with mounting a plurality of printheads on a plurality of printhead segment carriers. The printheads are then tested for correct operation and any defective printheads are replaced and the replaced printheads are tested. Once correct operation for all printheads on a carrier is confirmed, the printhead carrier is secured in place in a slot of an elongate member that receives an array of printhead carriers. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/261,934, filed Nov. 17, 2009, the entirety of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to safety windows. More specifically the present invention related to mechanical anchoring system for safety film to window frames.
[0004] 2. Description of Related Art
[0005] Windows are the single most dangerous part of a building to the occupants within the building. The powerful blast from a bomb can cause immeasurable destruction. A single square foot of glass can produce up to 200 deadly, razor-sharp fragments. In many instances, flying glass shards are what cause severe injury and even death. It is generally recognized around the world that between 80% and 90% of injuries or death in a bomb blast are due to cuts by the glass from the windows.
[0006] Historically, to achieve high levels of blast protection for existing glass, heavy gauge safety films were used in conjunction with various mechanical attachment systems. The safety films are designed to prevent the shattered glass from being propelled into a structure, where it can cause severe injury to occupants. In order to insure that the filmed glass remains within the frame, the film is attached to the window frame by metal “batten” systems that capture the edges of the film while being screwed into the frame. One such clamp is shown in FIG. 1 . These attachment systems are frequently referred to as “Load Transfer Members” because they transfer the energy from the blast through the film directly into the frame.
[0007] It would be desirable to find a mechanical attachment system that absorbs blast energy and reduces the transfer of energy to the window frames. It would be desirable to increase the blast load of windows without increasing the amount of lamination on the window.
SUMMARY OF THE INVENTION
[0008] The present invention provides a mechanical attachment system for attaching window film to the window frame, such as a batten, profile clamp or other structural device (referred to generally throughout the application as “attachment device”), which attachment device absorbs energy instead of simply transferring energy to the window frames (as is done in traditional devices). The absorption of energy is accomplished by incorporation of a flex area in the attachment device. The flex area bends or flexes when acted upon by blast loads and effectively eliminates the tearing effect (of the film) that all conventional mechanical attachment systems exhibit.
[0009] The mechanical attachment system of the present invention functions to keep the filmed glass within the frame during a blast event. During installation a film is wrapped behind the batten or profile clamp or other structural device (collectively referred to as the attachment device). The attachment device is then attached to the window frame with screws, thereby securing the film between the attachment device and the window frame. This system also preferably utilizes a rubber gasket attached to the attachment device which is positioned between the window film and the edge of the attachment device. The gasket serves the function of decreasing the shearing effect along the perimeter of the window.
[0010] Unlike conventional mechanical attachment systems, which merely transfer energy to the window frame, the inventive attachment system absorbs energy. In the present invention, every part of the system is designed to absorb a portion of the total energy, but no one piece absorbs all of the energy. The problem with conventional attachment systems is that they function to put a significant portion of the total energy into the frame. In particular, conventional profile clamps transfer nearly all of the energy to the window frame. In contrast, the inventive attachment system contains a flex area in the attachment device, which absorbs energy before it reaches the window frame.
[0011] The flex area in attachment device is designed to bend or flex but not break, and does not pull away from the window frame. The flex area is constructed in a way that the bending or flexing requires a lot of energy. This energy that is used to bend or flex the flex area is energy, therefore, that is not transferred to some other window component such as the window frame. As a result, significantly less energy is directed to the window frame or the screws holding the clamp to the window. The window can therefore be subjected to significantly greater force while still being held in place in the window frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a better understanding of the present invention, reference may be made to the accompanying drawings.
[0013] FIG. 1 shows a close up side view of a length of a prior art mechanical clamp.
[0014] FIG. 2 shows a perspective view of a length of one embodiment of the attachment device made in accordance with the present invention.
[0015] FIG. 3 shows a second perspective view of a length of one embodiment of the attachment device made in accordance with the present invention.
[0016] FIG. 4 shows a side view of a length of one embodiment of the attachment device made in accordance with the present invention.
[0017] FIG. 5 is a side by side comparison of a length of one embodiment of the attachment device made in accordance with the present invention before and after subjected to a blast load.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] In the mechanical attachment system of the current invention, an attachment device is used to attach or secure window film to the frame of a window. In one embodiment the attachment device is a mechanical clamp 1 , alternatively referred to as a batten or profile clamp. Other attachment devices, however, may be used so long as the device functions to absorb energy from the blast instead of merely transferring the energy to the window frame. The film used can be any film typically used in the industry, such as SafetyShield® Window Film sold by Madico, Inc.
[0019] FIGS. 2-4 are drawing of various views of a length of one embodiment of a mechanical clamp 1 constructed in accordance with the invention. The mechanical clamp 1 extends in a longitudinal direction (X) with two planar portions, which extend in a direction substantially perpendicular from each other. The angle between the two planar portions is chosen to fit the angle between the window frame (not shown) and the window glass (not shown), which is typically a right angle. To the extent that the angle is different for any specific windows, the angle between the two planar portions can be adjusted accordingly so that one planar portion fits against the window frame and one fits flush against the window pane.
[0020] In FIGS. 2-4 , a first planar portion 3 is designed to be attached to a window frame, preferably by screws through screw holes 4 positioned longitudinally along the first planar portion 3 . The location of the screw holes 4 (or otherwise the attachment point of the first planar portion 3 to the window frame) can vary. However as discussed below, the position of attachment and the length of the first planar portion 3 effect the function of the mechanical clamp's 1 capability to flex or bend. The planar section is not necessarily flat but is designed to rest against and/or be attached along a portion of a window frame.
[0021] The second planar portion 5 , when installed, abuts against the interior of the window pane. The film is secured between the window pane and the second planar portion 5 . Optionally, a gasket 6 is attached to the second planar portion 5 in between the film and the second planar portion 5 to minimize tearing at the point of contact. The gasket 6 is preferably made of a softer material such as synthetic or natural rubber. The planar section is not necessarily flat but is designed to rest against and/or be attached along a portion of a window pane.
[0022] At the point of intersection between the first planar portion 3 and second planar portion 5 is a flex zone 7 . The flex zone 7 functions to absorb energy as force (such as from a blast) is applied to the window pane. In the embodiment shown, the flex zone 7 is integral with both the first planar portion 3 and second planar portion 5 of the clamp 1 . In the embodiment, the entire clamp 1 is a unitary construction except for the gasket 6 . The flex zone 7 is curved to an extent that attachment will bend when force is applied to the window pane (and to the second planar portion 5 by extension). The screw holes 4 in the first planar portion 3 are positioned towards the end of the first planar portion 3 and slightly away from the flex zone 7 . This arrangement of screws contributes to the flex zones 7 ability to bend. For best results, it is important not to over drive the screws and the use of self tapping screws is preferable.
[0023] An example of the clamp 1 flexing or bending in response to force is shown in FIG. 5 . FIG. 5 illustrates the flexing effect on a mechanical clamp 1 when a window (not shown) is exposed to a blast force. The mechanical clamp 1 on the left is a new mechanical clamp 1 . The clamp 1 on the right is a drawing of an actual clamp 1 after a blast load of about 116 PSI. The clamp 1 was tested with annealed glass with safety film (as is typically used in actual application). As can be seen, the clamp 1 remains attached to the frame but is significantly bent in the flex zone 7 .
[0024] In the embodiment shown, the ability of flex zone 7 to flex or bend in response to a blast is achieved as a function of the degree of curvature in the flex zone 7 , which is substantially more pronounced than conventional mechanical attachments (such as that shown in FIG. 1 ). The position of the screw holes 4 in relation to the flex zone 7 also contributes the capability of the clamp 1 to bend or flex. In the embodiment shown, the clamp 1 is prepared by aluminum extrusion. As shown in FIGS. 2-4 , the thickness of the aluminum through the flex zone 7 is substantially the same throughout the entire clamp. The degree of flex is controlled via the thickness and/or configuration of the aluminum flex zone. Thinner aluminum at the flex zone creates greater flexibility for thinner safety films and thicker aluminum can be used for heavier films and higher loads. However, this structure is just one way to achieve the required flexibility in the clamp 1 and other arrangements are possible.
[0025] For example, the curvature in the flex zone 7 can be decreased while decreasing the thickness of the clamp 1 at the flex zone 7 . For another example different material could be used at the flex zone, such as plastic or composite to increase the flexibility. For another example, notches, cross-cuts or slits can be placed in the curve in order to prompt bending. Other methods of removing material from the flex zone can be implemented. In fact, any combination of the features described herein can be used to achieve the desired flexibility profile of the flex zone. FIG. 4A shows an alternate embodiment where notching 8 the extrusion at the curve in the flex zone 7 alters the flex zone to be able to flex more easily. Four notches are shown in the figure however more or less can be used depending on the desired amount of flex.
Testing
[0026] Tests on various window specimens were performed according to ISO 16933 Open Range Blast Test Protocol. The window construction of three specimens was as follows. The window frame was 1727 mm×1219 mm [68 inches×48 inches] extruded aluminum framed windows of 2.25 mm wall thickness. The style of the windows was fixed lite non-opening shop-front window frame. The glass used was 6 mm annealed float glass on the exterior lite, 12 mm air space and 6.76 mm annealed laminated safety glass. Insulated units mounted into frame with 10 mm edge rebate cover using compression gaskets. Window film used Madico SafetyShield® 800 200 micron multi-ply security grade window film applied to the inside surface of the glass extending onto the window frame by 40 mm and secured in place by an aluminum mechanical clamp constructed in accordance with the invention. The mechanical clamp was attached to the window frame on all four sides using 5.5 mm self drilling screws at 75 mm spacing.
[0027] The three test specimens were tested in accordance with classification EXV25 of ISO 16933: standard at a range of 25 meters from the explosive charge. Testing is divided into two categories, EXV which represents vehicle type threats, and SB or satchel bomb type threats meaning small suitcase or backpack size charges situated close in to the building. Under vehicle type testing, the designation denotes the distance the test articles are positioned from the 100 kg, 220 pounds of high explosive e.g. EXV25 denotes the test articles are 25 meters from the explosive charge.
[0028] The performance of each of the specimens was as follows. Testing in accordance with EXV25 achieved a GSA Level 3 B, which corresponds to a hazard level of “minimal hazard”. Testing in accordance with EXV19 achieved a GSA Level 3 B4, which corresponds to a hazard level of “low hazard”. Testing in accordance with EXV33 achieved a GSA Level 2, which corresponds to a hazard level of “no hazard”.
[0029] A second set of specimens were prepared using stainless steel No. 14 self tapping screws. The three test specimens achieved performance EXV33(B) (No Hazard) when subjected to the detonation of 100 kg TNT at 33 meters standoff in accordance with ISO 16933.
[0030] Various other samples were prepared altering the distance between the anchoring screws and the use of wet glaze bead on the external film. Superior performance was achieved in each instance.
[0031] There will be various modifications, adjustments, and applications of the disclosed invention that will be apparent to those of skill in the art, and the present application is intended to cover such embodiments. Although the present invention has been described in the context of certain preferred embodiments, it is intended that the full scope of these be measured by reference to the scope of the following claims.
[0032] The disclosures of various publications, patents and patent applications that are cited herein are incorporated by reference in their entireties. | The present invention provides a mechanical attachment system for attaching window film to the window frame, such as a batten, profile clamp or other structural device (referred to generally throughout the application as “attachment device”), which attachment device absorbs energy instead of simply transferring energy to the window frames (as is done in traditional devices). The absorption of energy is accomplished by incorporation of a flex area in the attachment device. The flex area bends or flexes when acted upon by blast loads and effectively eliminates the tearing effect (of the film) that all conventional mechanical attachment systems exhibit. | 4 |
[0001] This application is a continuation of U.S. Patent Application Ser. No. 11/174,437, filed Jul. 1, 2005, which is a continuation of U.S. patent application Ser. No. 09/790,786, filed Feb. 22, 2001, which claims priority under 35 U.S.C. §119 from U.S. Provisional Application Ser. No. 60/184,971, filed Feb. 25, 2000, each of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] Vitiligo is a cutaneous disease in which there is a complete loss of pigment in localized areas of the skin. This loss of pigment results in the effected areas being completely white. This condition has a predilection for the skin around the mouth and eyes. The result is cosmetically disfiguring, especially for dark skinned people. Furthermore, the depigmented skin is sun sensitive, and thus is subject to sunburns and skin cancer. In sum, vitiligo is both cosmetically and practically distressing to patients afflicted with the disease.
[0003] In normal skin, varying shades of brown are seen (depending on a person's race) representing the pigment melanin. This pigment is produced by a cell type known as a melanocyte. In vitiligo, there is an absence of melanocytes in the areas afflicted with the disorder. An absence of melanocytes results in an absence of melanin pigment, and thus the melanin-free area is white. Normal skin responds to ultraviolet light with an increase in the brown pigment melanin (tanning). Specifically, ultraviolet radiation stimulates melanocytes to proliferate and produce more melanin.
[0004] Attempts have also been made to “tan” vitiligo areas using ultraviolet light treatments. The ultraviolet spectrum is divided into two portions, “UVA” and “UVB,” which is light of 320-400 nm and 290-320 nm in wavelength, respectively. UVB is much more effective at producing a tan in normal skin. In normal skin, melanocytes reside in the epidermis, which is the outer layer of the skin. The epidermis is only 0.1 mm thick, so the melanocytes are very near the surface. UVB radiation can only penetrate to about 0.1 mm, but this is sufficient to reach the melanocytes. In patients with vitiligo, these epidermal melanocytes are gone. In some cases, there are surviving melanocytes deeper in the skin down the hair follicles. These melanocytes may be several millimeters deep. UVB cannot penetrate this deep in the skin to stimulate these surviving deep melanocytes. Exposure to UVB results in a sunburn at the surface of the skin with no stimulation of these deep melanocytes. Thus attempts to repopulate the vitiligo areas with melanocytes deep in the skin in response to UVB exposure have failed. UVA will penetrate a bit deeper in the skin than UVB. However, UVA is very poor at stimulating melanocytes to proliferate and migrate.
DESCRIPTION OF RELATED ART
[0005] The present invention uses an excimer laser to restore pigmentation to skin areas afflicted with vitiligo, and is an improvement over current treatments for vitiligo. Currently, treatments for vitiligo suffer from a number of drawbacks. For instance, Fitzpatrick's Dermatology in General Medicine, Vol. 1, Chapter 89 (5 th ed., I. M. Freedberg et al., eds., 1999) teaches the use of sunscreens and cosmetic cover-ups including dyes and conventional makeup as a way to mask skin areas afflicted with vitiligo. However, the ability of sunscreens to minimize contrast between normal skin and vitiligo-afflicted areas has been disappointing. Sunscreens, as well as cosmetics and dyes, are not permanent. These products tend to rub-off and have been of limited value in areas such as the lower neck, wrists and hands. In addition, unlike the present invention, sunscreens and cosmetics cover-ups do not attempt to treat vitiligo, but simply blend in the affected areas with the surrounding skin. The prior art also teaches the use of topical glucocortoids to treat isolated areas of vitiligo. Fitzpatrick's Dermatology in General Medicine. However, the overall results tend to be disappointing. The present invention improves on these treatments by providing a more permanent restoration of pigmentation to vitiligo affected areas, with a relatively high rate of success.
[0006] Another known treatment for vitiligo attempts to increase the action of UVA light by combining exposure to UVA with a chemical that is applied to the skin to increase sensitivity to UVA. Fitzpatrick's Dermatology in General Medicine, Vol. 1, Chapter 89 (5 th ed., I. M. Freedberg et al., eds., 1999). This chemical is known as psoralen, and psoralen and UVA together are known as PUVA. Specifically, high output UVA (320-400 nm) light bulbs are utilized within an indoor phototherapy unit. The patient applies psoralen to the effected areas, then stands inside the phototherapy unit for exposure to the UVA light emitted by conventional tube-style bulbs.
[0007] This type of PUVA treatment suffers from a number of drawbacks. Unlike the present invention, PUVA treatment is to the whole body, not just the vitiligo areas. Therefore PUVA therapy has been associated with the development of skin cancers. PUVA treatment is also time-consuming; a minimum of 100 treatments, given 2-3 times per week over many months, is necessary before any response is seen. In addition, this treatment has had a relatively low success rate. Significantly less than 50% of patients will respond to this treatment. The present invention, however, treats only those skin areas afflicted with vitiligo, and thus minimizes the risk of skin cancer. The present invention also is less time consuming, and enjoys a relatively higher success rate.
[0008] Topical PUVA also may be used to treat localized patches of vitiligo and consists of applying a topical preparation of 8-methoxypsoralen to the patch of vitiligo and exposing the patch to UVA radiation at intervals of two to three times weekly. This type of PUVA treatment also has a number of drawbacks. Erythema, blistering and hyperpigmentation of surrounding skin are common complications. In addition, the success rate is relatively low. Repigmentation is seen in only about half of treated patients. Westernof, W., et al., “Treatment of Vitiligo with UV-B Radiation vs. Topical Psoralen Plus UV-A,” Arch. Dermatol; 1997; 133:1525-28.
[0009] Phototherapy with UV-A radiation and oral psoralens is another known treatment. UV-A irradiation occurs at intervals of two to three times weekly and is generally maintained for months to greater than a year. Once again, the success rate is relatively low. Elliott, J., “Clinical Experiences With Methosaxalen in the Treatment of Vitiligo”, J. Invest Dermatol, 1959; 32: 311-314; Farah, F. et al, “The Treatment of Vitiligo with Psoralens and Triamcinolone By Mouth”, Br. J. Dermatol, 1969; 79: 89-91; Ortonne J., “Psoralen Theraphy In Vitiligo”, Clin. Dermatol; 1989; 7:120-135. Moreover, side effects of this type of PUVA include burning, nausea, erythema, lentigenes, pruritus, and cataracts.
[0010] UVB phototherapy is much more effective at stimulating melanocytes than PUVA. However, regular UVB light cannot penetrate the skin deeper than the epidermis, and hence is completely ineffective in stimulating the deep melanocytes underneath patches of vitiligo. The present invention overcomes this problem in the prior art through the use of an excimer laser which emits laser light in the ultraviolet range and provides higher energy fluences thereby decreasing the treatment time.
[0011] M. Thissen et al., Laser Treatment for Further Depigmentation in Vitiligo, International Journal of Dermatology, Vol. 36 (1997) teaches the use of a ruby laser to depigment normal skin and bleach it to a white color. Ruby lasers, unlike excimer lasers, employ a-ruby crystal to generate laser light in the red spectrum. The laser light is used to depigment normal skin, and does not attempt to restore or treat skin areas afflicted by vitiligo. Therefore, unlike the present invention which attempts to stimulate melanin production and restore pigmentation, patients subjected to the Thissen treatment end up depigmenting their remaining normal skin. The drawbacks of this treatment are that the depigmented skin lacks melanin and is the color white, which is generally less aesthetically desirable than the natural skin color of the patient. This depigmented skin is also more sensitive to the sun than normally pigmented skin, and the patient with depigmented skin must be protected from the sun for the rest of his or her life. Finally, the Thissen article acknowledges that this method is only effective in vitiligo afflicted patients where the skin has become over 80% depigmented.
[0012] K. Sasaki et al., Role of Low Reactive-Level Laser Therapy (LLLT) in the Treatment of Acquired and Cicatrical Vitiligo, Laser Therapy, Vol. 1 No.3 (1989) teaches use of a diode laser, either alone or in combination with an argon laser, to revive dormant or malfunctioning melanocytes in order to repigment vitiligo afflicted skin areas. This technique suffers from the disadvantage that both the argon and diode lasers are needed in order to treat cicatrical-type vitiligo, or vitiligo that follows after scarring or trauma. Argon lasers also suffer from the disadvantage that they may cause thermal damage to the skin. In addition, argon lasers as disclosed in Sasaki emit visible light (488 nm and 514.5 nm), while diode lasers emit infrared light (830 nm). Unlike the present invention, these lasers do not emit UV light, and therefore do not benefit from the special ability UVB light has in stimulating melanocyte growth and melanin production.
[0013] H. Yu et al, Helium-Neon Laser Treatment Induces Repigmentation in Segmental-Type Vitiligo, Journal of Investigative Dermatology, Vol. 112(4) (1999) teaches use of a Helium-Neon laser that emits light in the visible red to infrared range, as opposed to UV light. Unlike the present invention, Helium-Neon laser light suffers from the disadvantage that it does not stimulate melanocytes directly, but instead induces nerve growth. For this reason, this method of treating vitiligo is confined to segmental-type vitiligo, which is vitiligo caused by dysfunction of nerves.
[0014] Lasers have also been used to treat vitiligo to aid in skin grafting. R. Kaufman, et al., Grafting of In Vitro Cultured Melanocytes onto Laser-Ablated Lesions in Vitiligo, ACTA Demato-Veneriologica, Vol. 78/2 (1998); J. S. Yang et al., Treatment of Vitiligo with Autologous Epidermal Grafting by Means of Pulsed Erbium: YAB Laser, Journal of the American Academy of Dermatology, Vol. 38/2 (1998). Unlike the present invention, these techniques are invasive and require that the vitiligo affected areas be relatively small and stable.
[0015] Narrowband UV-B phototherapy using a spectrum of 311-315 nm wavelength with a peak emission of 311 nm has been used to treat vitiligo. Westerhof et al. teaches the use of narrowband UV-B phototherapy at intervals of two times per week for four to twelve months. However, this method requires regular phototherapy sessions several times a week for up to a year to achieve a therapeutic response. UV-B phototherapy in general has few side effects and is mainly limited to erythema.
[0016] What is needed is a method of treating vitiligo with UVB light that treats only the areas of vitiligo with increased precision, at higher energy fluences, to reduce length of treatment. What is also needed is a method of treating vitiligo that is as effective as UVB light in stimulating melanocytes, but without the disadvantage of being unable to penetrate beyond the epidermal skin layer. What is also needed is a method of treating vitiligo that only treats the areas of the vitiligo, and not the entire body, to reduce the risk of skin cancers. Finally, what is needed is a method that restores pigmentation to skin areas afflicted with vitiligo, rather than simply covering the affected areas or bleaching normal skin white, so that the result is both more permanent and more aesthetically pleasing.
BRIEF SUMMARY OF THE INVENTION
[0017] The present invention is a method of treating vitiligo using an excimer laser, a laser which produces light in the UVB range. The present invention includes a method for treating vitiligo by incrementally increasing exposure of afflicted areas of skin with UVB laser light to restore the pigmentation in the areas afflicted with vitiligo. The present invention overcomes the problems associated with current vitiligo treatments through the use of an excimer laser. Laser light is coherent and collimated whereas regular light is incoherent and divergent, allowing laser UVB light to penetrate deeper into skin and quickly stimulate deep melanocytes underneath patches of vitiligo. Therefore unlike regular UVB light or, PUVA therapy, the present invention is able to better stimulate deep melanocytes, and is able to deliver higher energy fluences in less time than known treatments. Another advantage of the present invention is that laser treatment is confined to only those areas afflicted with vitiligo, not to normal skin, and thus significantly reduces risk of skin cancers over other types of therapy such as PUVA treatments. Yet another advantage of the present invention is that the vitiligo areas are treated and made darker, making the areas better match the natural skin color of the patient, as opposed to simply bleaching the surrounding non-vitiligo areas to an unnatural white. Finally, the present invention changes the actual pigment of the skin, and therefore will not rub or wash-off.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0019] FIG. 1 depicts vitiligo involving periocular skin in an individual with phototype V skin before treatment.
[0020] FIG. 2 depicts vitiligo involving the extensor elbow in an individual with phototype V skin before treatment.
[0021] FIG. 3 depicts vitiligo involving the periocular skin in an individual with phototype III skin before treatment.
[0022] FIG. 4 depicts a comparison of the number of treatments and the degree of repigmentation in the study population.
[0023] FIG. 5 depicts complete repigmentation after 5 treatments.
[0024] FIG. 6 depicts spotty follicular repigmentation after 12 treatments.
[0025] FIG. 7 depicts focal repigmentation after 12 treatments.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The present invention is a method of using UVB laser light to treat vitiligo. Laser light is different than regular light in that it is coherent and collimated, which can be thought of as more “concentrated.” A given dose of laser light is often much more effective in producing photochemical reactions than conventional light. Treatment of vitiligo with UVB laser light is superior because laser light 1) penetrates deeper in the skin than conventional light, and 2) a given dose of light is delivered much more quickly with laser light. This second effect becomes important if stimulation of melanocytes has a time component, i.e. stimulation is more effective if done quickly.
[0027] Also claimed and disclosed is a method of using UVB laser light to treat vitiligo where the time of exposure to the vitiligo afflicted skin areas is gradually increased. A diagnosis of vitiligo is made clinically, and the absence of melanin is confirmed by Woods light examination. A Wood's light examination uses UV light, also known as “black light,” to accentuate areas of white color. In the practicing invention, a patient afflicted with vitiligo is treated by exposing the afflicted area to the UVB laser beam at periodic intervals. For example, the exposure to the vitiligo afflicted skin areas can be administered between 1 to 5 times per week. The first treatment would last for up to 5 seconds, depending on the intensity setting of the laser beam. The greater the intensity, the shorter the exposure to the beam. The exposure time for each treatment would be gradually increased, to a maximum of 10 seconds.
[0028] In one embodiment of the invention, an excimer laser is used to generate the UVB laser light. An excimer laser is a laser which uses a rare-gas halide or rare-gas metal vapor and emits laser light in the ultraviolet (126 to 558 nm) range. Currently, only excimer lasers emit laser light in the UV range, although any future lasers that emit light in the UVB range would also be encompassed by this invention. The laser used should operate in a range between 290 and 320 nm in wavelength, the UVB range of light. The laser should be utilized at a setting of not more than 120 mwatts.
[0029] A 308 excimer laser from the Surgilight Corporation, Winter Park Fla., is preferred for use in practicing the present invention. This laser operates at 308 nm via a fiber optic cable with pulse duration of 120 nsec, fired at repetition rate of 20 hz. The laser spot size is 10×10 mm. A photometer measures laser output, and the laser is utilized at a setting of 60 mwatts. In one preferred method of treatment, a patient with vitiligo is exposed to the 308 nm excimer laser three times a week. The first treatment lasts 2 seconds. The patient returns, and if there is no sunburn, the treated area is retreated again for 2 seconds. If there is sunburn, treatment is withheld until the sunburn is gone. On the third visit, if there is no sunburn, the dose is increased to 4 seconds. This is repeated the fourth visit, and then increased to 6 seconds on the fifth visit. On the sixth visit, 6 seconds is given again. Therefore, in this preferred method, each dose is repeated once, then increased by two seconds, to a maximum of 10 seconds. Treatment is continued for one month, or until repigmentation occurs, which is a much shorter time than PUVA therapy, which typically takes 6 months before any result is seen. Repigmentation is the appearance of brown pigment in the treated area, and is documented by standardized photography. In preliminary trials, four out of five patients receiving treatment for a minimum of nine sessions showed some response. This is a significant and substantial improvement in success rate over PUVA, glucocortoids, or any other current therapy for vitiligo. The repigmented skin is also relatively more permanent than other treatments such as sunscreens and cosmetic cover-ups, and will not rub-off.
[0030] When compared to standard phototheraphy, the 308 nm excimer laser has the advantage of having increased precision and the ability to deliver higher energy fluences thereby decreasing treatment time.
EXAMPLES
[0031] The following are intended as non-limiting examples of the invention.
[0032] Six men and twelve women with multiple discreet chronic stable patches of vitiligo enrolled in the study. Most patients had received and failed a variety of prior therapies for vitiligo (Table 1). No patient received any additional vitiligo therapy for at least one month prior to and during the study.
[0033] Eighteen patients started the study with a total of twenty-nine treated vitiligo patches. All patients had untreated vitiligo patches that were used as controls. Test areas of vitiligo were treated using a 308-nm xenon chloride excimer laser. A 120-ns, 20-hz, pulse was used with a 10-mm by 10-mm spot size and a power output of 60 mw of laser light. Lesions were treated three times a week for a maximum of 12 treatments. Exposure time was started at 2 seconds and increased by 2 seconds at every other visit until complete repigmentation occurred or until the protocol (12 treatments) was completed. Treatment was withheld if sunburn was observed and held until resolution.
[0034] Treated areas were evaluated for repigmentation and erythema on separate four point scales. Repigmentation was graded on the percentage of treated area of repigmentation as follows: 0:0%, 1:1-25%, 2:26-75% and 3:76-100%. Sunburn (erythema) was similarly graded as follows: 0-None, 1-Mild, 2-Moderate, 3-Severe. Patients with no repigmentation were defined as non-responders.
[0000] Results
[0035] Twelve patients with 23 patches completed at least six treatments. Six patients with 11 patches of vitiligo completed all twelve treatments that required an average of four weeks to complete. Six patients dropped out of the study before completion of six treatments and resulted in one slight repigmentation and five non-responders. Two of the non-responders developed mild erythema. Twelve patients with six or more total treatments of 23 vitiligo patches resulted in partial repigmentation in 57% of twenty-three patches. Six patients who completed twelve treatments of 11 vitiligo patches resulted in partial repigmentation in 87% of eleven patches ( FIG. 4 ). There were no serious adverse events. Mild sunburn with persistent erythema lasting up to three weeks was observed in some patients. Patients with the most repigmentation were skin-types III-VI. Table 1 sets forth the results.
TABLE 1 Demographics and Study Results of Patients Involved In the Protocol Skin Prior Treatment Treatments % Repig- Patient Sex Phototype Treatment Locations Received mentation * Erythema ** 1 M V TS Periocular 5 3 0 Forearm 12 3 0 2 F III PUVA Periocular 12 1 0 Back 12 1 0 Hand 12 0 0 Thigh 12 1 0 3 F I None L. Forearm 12 1 1 4 F III-IV None L. Preauricular 9 5 M II None L. Neck 3 0 1 6 F II TS. Folate L. Hand 5 1 0 7 F IV PUVA Finger 12 0 0 8 M II TS Abdomen 3 0 1 9 F VI TS R. Temple 2 0 0 10 F II None R. Wrist 6 11 F III-IV None R. Axilla 8 1 1 Sternum 8 1 1 12 F None R. Axilla 1 0 0 13 M III-IV None Chin 10 0 1 L. Elbow 10 0 1 L. Arm 10 0 1 14 M II PUVA L. periocular 10 0 1 R. Elbow 10 1 0 Chin 10 0 1 15 F II PUVA L. Shin 9 1 0 L. Elbow 9 0 1 16 F II TS Forearm 5 0 0 17 M IV PUVA Forehead 12 1 0 Chin 12 1 0 18 F V None Elbow 12 2 0 * Repigmentation: 0 = 0; 1 = 1-25%; 2 = 26-75%; 3 = 76-100% ** Erythema: 0 = none; 1 = mild; 2 = moderate; 3 = severe
[0036] While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. All patent applications, patents, patent publications and literature references cited in this specification are hereby incorporated by reference in their entirety. | Disclosed herein is a novel method of treating vitiligo by using an excimer laser that emits light in the UVB range. The invention includes a method of incrementally increasing exposure of affected vitiligo areas with UVB laser light from an excimer laser to restore pigmentation to skin areas afflicted with vitiligo. | 0 |
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a surgical needle comprising a point and dual cutting blades. The point is defined by a symmetrical angle of width and an angle of slope. The needle point geometry and the dual cutting blades provide a flap incision and a reduction in the tissue penetration properties.
The Applicants are not aware of any prior art which, in their respective judgements as persons skilled in the art of surgical needle of this invention. However, to fully develop the background of the invention and establish the state of the art, the following references are cited:
U.S. Pat. No. 3,094,123 issued June 18, 1963 which discloses a surgical needle having an angle of slope and an angle of sharpness and providing a reduction in tissue penetration force; and
U.S. Pat. No. 2,841,150 issued July 1, 1958 which discloses a surgical needle having a triangular cross-section. Both of these patents are incorporated by reference.
The surgical needle of this invention has advantages over the references above. The needle point geometry and the V-shape cross-section provide a reduction in the tissue penetration force and a flap incision, rather than a circular, eliptical or triangular incision of the prior art needles. The advantage of the flap incision is that the flap formed can then close over the puncture defect. This may accelerate the physiological healing of the puncture defect. The flap may also reduce fluid leakage from soft tissue. Another advantage is the dual cutting blades which can provide up to four cutting edges.
Still another advantage is that the V-shape cross-section of the needle is based on a structural beam concept (which is described in U.S. Pat. No. 2,841,150). The thickness of the needle sides can thus be reduced while providing sufficient rigidity to penetrate tissue. Alternatively, the needle height and width can be decreased which reduces the tissue penetration force.
The needle of this invention is useful as a cutting edge or a taper point surgical needle. The needle is used in the same manner as a conventional cutting edge or taper point needle.
A surgical needle providing a reduction in the tissue penetration force and a flap incision has now been invented. A straight or curved needle is within the scope of the invention. The needle comprises a penetration portion, a middle portion and a butt portion. The penetration portion initiates at a point. The point is defined by a symmetrical angle of width and an angle of slope. The penetration portion terminates in dual cutting blades having a V-shape cross-section. The cutting blades are joined at the apex of the V-shape. The butt portion of the needle has strand attachment means.
In a preferred embodiment, the point is defined by a symmetrical angle of width of about 20° to 35°. In another preferred embodiment, the point is defined by an angle of slope of about 20° to 35°. In other preferred embodiments, the sides of the V-shape cross-section have an included angle of about 60°; and, the middle portion has a cross-section as described in FIG. 7 below or a V-shape cross-section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are top and side views, respectively, of the penetration and middle portions of a straight needle of this invention;
FIG. 3 is a section view on the line 3--3 of FIG. 1 showing a cross-section of the penetration portion of the needle;
FIGS. 4 and 7 are section views on the lines 4--4 of FIG. 1 and 7--7 of FIG. 6 showing alternative cross-sections of the middle portion of the needle;
FIG. 5 is a projected view of FIGS. 1 and 2;
FIG. 6 is a side view of a curved needle of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 describe the penetration and middle portions of a straight surgical needle of this invention. The needle initiates at a point 1 and terminates in dual cutting blades 2. The sides 3 of the penetration portion have a V-shape cross-section (shown in FIG. 3) and are jointed at the apex 4 of the V-shape. The point geometry of the needle of this invention reduces the force necessary to penetrate tissue. The point 1 is defined by a symmetrical angle of width and an angle of slope. In a preferred embodiment, the point 1 is defined by a symmetrical primary and secondary angle of width, θ 1 and θ 2 , respectively; and by a primary and secondary angle of slope, α 1 and α 2 , respectively. The preferred angle for θ 1 is about 20° to 35° and for θ 2 is about 5° to less than 20°; and for α 1 is about 20° to 35° and for α 2 is about 5° to 30° with the proviso that α 2 is always less than α 1 . The most preferred angle for θ 1 is about 30° and for θ 2 is about 10°; and for α 1 is about 25° and α 2 is about 10°. The secondary angle of width θ 2 is always less than the primary angle θ 1 ; and the secondary angle of slope α 2 is always less than the primary angle α 1 . Within the scope of this invention is a point, defined by primary and secondary angles of width and angles of slope, in which the tip is rounded or blunted, for example, by grinding.
FIG. 3 is a section view on the line 3--3 of FIG. 1 and describes the preferred V-shape cross-section of the penetration portion. FIG. 4 is a section view on the line 4--4 of FIG. 1 and describes a cross-section of the middle portion of the needle. An alternative cross-section is described in FIG. 7. The width of the cutting edges 2 and the thickness of the sides 3 are constant. The height and width of the sides 3 of the penetration portion increase away for the needle point to a maximum height 5 and maximum width 6 of the middle portion shown in FIG. 4. The maximum height 5 and width 6 is less than or equal to the maximum height and width of the penetration portion. The maximum height 5 of the needle is dependent on the type of surgical operation or procedure. The following types of surgical operations or procedures and the range of the maximum height 5 are examples: ophthalmic--about 0.006 to 0.011 inches; thoracic--about 0.011 to 0.022 inches; plastic or reconstructive--about 0.013 to 0.017 inches; general--about 0.022 to 0.050 inches (and larger for special applications); and retention suturing--up to about 0.062 inches. Using these ranges with the included point angle and needle point geometry, the remaining dimensions of the needle can be determined. The included angle of the sides 3 in the penetration and middle portions of the needle is constant. In the preferred embodiment, the included angle is about 60°. The apex 4 of the sides 3 can be rounded as shown in FIG. 4.
FIG. 5 describes a projected view of the penetration and middle portions of a straight surgical needle described in FIGS. 1 and 2. The butt portion of a straight needle described in FIGS. 1, 2 and 5 contains a strand attachment means, for example, a channel 7 described in FIG. 6, or a drilled end.
FIG. 6 describes a side view of a curved needle of this invention. The length of the V-shape cross-section of the penetration portion is defined by an included point angle, φ which for illustration only is shown as about 60°. It is to be understood that an included point angle of φ below 60° is within the scope of this invention. As a maximum, the included point angle, φ can be the arc circumscribed by the needle of FIG. 6; that is, the entire cross-section of the needle of FIG. 6 can be V-shape.
In FIG. 6, the apex 4 is shown on the inside radius and the dual cutting edges 2 are shown on the outside radius of the needle. However, it is within the scope of this invention to have the apex on the outside radius and the dual cutting edges on the inside radius of the needle. The middle portion of the needle is defined by the remaining curved portion of the needle in FIG. 6. The butt portion of the needle, which may also be curved, contains a strand attachment means, for example, a channel 7 or a drilled end.
FIG. 7 is a section view on the line 7--7 of FIG. 6 and describes a cross-section of the middle portion. An alternative cross-section is described in FIG. 4. The middle portion of a straight or curved needle of this invention can also have a solid elliptical, triangular or circular cross-section. Generally, the configuration of the middle portion is not critical provided that the maximum height and width of the middle portion is less than or equal to the maximum height and width of the penetration portion. The maximum height 5a and width 6a is less than or equal to the maximum height and width of the penetration portion.
In the manufacture of needles having a V-shape cross-section throughout, preformed sheet stock is used. The needles, either straight or curved, are manufactured by conventional techniques, e.g., as generally described in U.S. Pat. No. 2,841,150. In the manufacture of needles where only the penetration portion has a V-shape cross-section, the needles are cut from stock having a solid cross-section. The V-shape is then formed by a stamping or swaging operation. The needles are then manufactured by conventional techniques. The honing of the symmetrical angle of width and the angle of slope, and the sharpening of the dual cutting edges is then accomplished, for example, by machine grinding. The grinding machines and grinding techniques used are conventional.
The needle can be manufactured from any known surgical suture needle material, for example, steel or a nonferrous alloy. Other materials, such as polymers, or composite polymer/metal materials may also be used. | This invention relates to a surgical needle comprising a point and dual cutting blades. The point is defined by a symmetrical angle of width and an angle of slope. The needle point geometry and the dual cutting blades provide a flap incision and a reduction in the tissue penetration properties. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to the electrical, electronic, and computer arts, and more particularly relates to infinite impulse response systems.
BACKGROUND
[0002] Infinite impulse response (IIR) digital filters, and in particular, biquad infinite impulse response (BIIR) filters, have been widely used in the field of communications, among other applications. For example, such digital filters are often used to remove noise, enhance communication signals, and/or synthesize communication signals. Compared to a finite impulse response (FIR) filter, an IIR filter is generally much more efficient in terms of achieving certain performance characteristics with a given filter order. This is primarily because an IIR filter incorporates feedback and is capable of realizing both poles and zeros of a system transfer function, whereas an FIR filter can only realize zeros of a transfer function. Moreover, IIR filters use a smaller number of coefficients to obtain a required impulse response of a desired filter.
[0003] Higher order IIR filters can be obtained by cascading multiple biquad IIR filters with appropriate coefficients. Another way to design higher-order IIR filters is to employ a single complex section. This latter approach is often referred to as a direct form implementation. The cascaded biquad implementation generally executes slower than the direct form implementation but generates smaller numerical errors than the direct form implementation. Another disadvantage of the direct form implementation is that the poles of such single-stage high-order polynomials get increasingly sensitive to quantization errors; second-order polynomial sections (i.e., biquads) are less sensitive to quantization effects.
[0004] One significant disadvantage of a BIIR implementation in a vector processor environment is a requirement for sequential processing of output samples. Conventional direct form implementation BIIR filter implementations utilize only a relatively small subset (e.g., three) of the total number of multipliers available. This implementation is inefficient, and is prone to execution stalls, and hence is undesirable.
SUMMARY
[0005] Principles of the invention, in illustrative embodiments thereof, advantageously provide techniques for eliminating the requirement for sequential processing of output samples in a BIIR system. In this manner, techniques of the invention advantageously optimize the processing efficiency and performance of a BIIR system, such as a BIIR filter, particularly in a vector processor environment.
[0006] In accordance with one embodiment of the invention, a BIIR system includes a first delay line for receiving at least one input data sample and generating delayed input samples as a function of the input data sample. The BIIR system further includes a second delay line including multiple delay elements connected together in a series configuration for generating delayed output samples. An input of one of the delay elements receives at least one output data sample of the BIIR system. A summation element in the BIIR system generates the output data sample of the BIIR system as a function of an addition of at least first and second signals and a subtraction of at least a third signal. The third signal includes at least a first delayed output sample generated by the second delay line multiplied by a first prescribed value. The first delayed output sample and the output data sample of the BIIR system are temporally nonadjacent to one another, whereby the BIIR system eliminates a dependency between the output data sample and a temporally adjacent delayed output sample generated by the second delay line. One or more BIIR systems can be implemented in an integrated circuit.
[0007] In accordance with another embodiment of the invention, a method of implementing a BIIR system includes the steps of: generating a plurality of delayed input samples as a function of an input data sample received by the BIIR system; generating a plurality of delayed output samples as a function of at least one output data sample of the BIIR system; generating the output data sample of the BIIR system by summing at least a first signal and a second signal and subtracting at least a third signal, the third signal comprising at least a first one of the delayed output samples multiplied by a first prescribed value, the first one of the delayed output samples and the output data sample of the BIIR system being temporally nonadjacent to one another, whereby the BIIR system is operative to eliminate a dependency between the output data sample and a temporally adjacent delayed output sample.
[0008] These and other features, objects and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The following drawings are presented by way of example only and without limitation, wherein like reference numerals indicate corresponding elements throughout the several views, and wherein:
[0010] FIG. 1 is a block diagram depicting at least a portion of an exemplary second order IIR filter 100 which can be modified to implement techniques of the invention;
[0011] FIG. 2 is a graphical illustration depicting pole locations for an exemplary BIIR filter;
[0012] FIG. 3 is a conceptual view depicting three processor cycles along with exemplary operations performed during each of the cycles in a direct implementation of a BIIR filter;
[0013] FIG. 4 is a graphical illustration depicting pole locations for the exemplary transformed BIIR filter, according to an embodiment of the invention;
[0014] FIG. 5 is a conceptual view depicting two consecutive processor cycles along with exemplary operations performed during each of the cycles in an implementation of an illustrative transformed BIIR filter, according to an embodiment of the invention;
[0015] FIG. 6 is a block diagram depicting at least a portion of an exemplary BIIR filter circuit, according to an embodiment of the present invention;
[0016] FIG. 7 is a graphical illustration depicting pole locations for an exemplary transformed BIIR filter, according to another embodiment of the invention;
[0017] FIG. 8 is a block diagram depicting at least a portion of an exemplary BIIR filter circuit, according to another embodiment of the present invention; and
[0018] FIG. 9 is a block diagram depicting at least a portion of an exemplary processing system, formed in accordance with an aspect of the present invention.
[0019] It is to be appreciated that elements in the figures are illustrated for simplicity and clarity. Common but well-understood elements that may be useful or necessary in a commercially feasible embodiment may not be shown in order to facilitate a less hindered view of the illustrated embodiments.
DETAILED DESCRIPTION
[0020] Embodiments of the present invention will be described herein in the context of illustrative methods and apparatus for efficiently implementing a BIIR filter. It is to be appreciated, however, that the invention is not limited to the specific methods and apparatus illustratively shown and described herein. Rather, embodiments of the invention are directed broadly to techniques for eliminating the sequential processing of output samples in a BIIR system. Moreover, it will become apparent to those skilled in the art given the teachings herein that numerous modifications can be made to the embodiments shown that are within the scope of the present invention. That is, no limitations with respect to the specific embodiments described herein are intended or should be inferred.
[0021] A BIIR transfer function is typically represented in one of the following forms:
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2
)
[0000] where a 1 and a 2 are filter coefficients, which are usually real numbers, b 1 and b 2 are locations of filter poles, which are usually complex numbers such that b 1 =R b +I b i and b 2 =R b −I b i (i=√{square root over (−1)}), y[n] is the calculated filter output, and y[n−1] and y[n−2] are previously calculated filter outputs (i.e., the two calculated output samples immediately preceding y[n]). Equation (1) is considered a z-transform form and equation (2) is a regression equation form.
[0022] IIR is a property of signal processing systems. Systems with this property are known as IIR systems or, when dealing with filter systems in particular, as IIR filters. IIR systems have an impulse response function that is non-zero over an infinite length of time. This is in contrast to finite impulse response (FIR) filters, which have fixed-duration impulse responses.
[0023] FIG. 1 is a block diagram depicting at least a portion of an exemplary second order IIR filter 100 which can be modified to implement techniques of the invention. It is to be understood that the invention is not limited to any specific IIR filter topology, and that the coefficients and number of feedback/feedforward paths in the filter are implementation-dependent. In this example, IIR filter 100 includes a summation block 102 , a first delay block 104 and a second delay block 106 connected together in a recursive configuration.
[0024] Summation block 102 is operative to receive an input signal (x) supplied thereto and to generate an output signal (y) of the filter via a feedforward signal path. Delayed versions of the output signal y, generated by delay blocks 104 and 106 , are fed back to summation block 102 , via separate feedback signal paths, and summed with the input signal x to generate the filter output signal y.
[0025] More particularly, input signal x is multiplied in block 108 by a coefficient (i.e., constant) b to generate the signal bx supplied to summation block 102 . The output signal y is fed to the first delay block 104 to generate a delayed output signal yz −1 , which is multiplied by a coefficient a 1 to generate a signal a 1 yz −1 . The signal a 1 yz −1 is then supplied to summation block 102 via a first feedback signal path. Concurrently, the signal yz −1 generated by the first delay block 104 is fed to the second delay block 106 to generate a delayed output signal yz −2 , which is multiplied by a coefficient a 0 to generate a signal a 0 yz −2 . The signal a 0 yz −2 is then supplied to summation block 102 via a second feedback signal path. In this manner, the output signal y can be represented as follows:
[0000] y=bx+a 0 yz −1 +a 1 yz −2 (3)
[0000] Solving equation (3) for the filter transfer function H(z) yields the following derivation:
[0000]
bx
=
y
-
a
1
z
-
1
y
-
a
0
z
-
2
y
bx
=
y
(
1
-
a
1
z
-
1
-
a
0
z
-
2
)
x
y
=
b
1
-
a
1
z
-
1
-
a
0
z
-
2
H
(
z
)
=
x
y
=
bz
2
z
2
-
a
1
z
-
1
-
a
0
(
4
)
[0026] FIG. 2 is a graphical illustration depicting pole locations for an exemplary BIIR filter. With reference to FIG. 2 , a first pole 202 is located at a position of R b on the real axis and I b on the imaginary axis, and a second pole 204 is located at a position of R b on the real axis and −I b on the imaginary axis. As shown, the location of all poles lie within the boundary of a unit circle 206 , which is a fundamental requirement of any IIR filter since it assures filter stability. More particularly, the system transfer function allows one to judge whether or not the system is bounded-input, bounded-output (BIBO) stable. A BIBO stability criterion requires that a radius of convergence (ROC) of the system includes the unit circle. For example, for a causal system, all poles of the transfer function must have an absolute value smaller than one; i.e., all poles must be located within the boundary of the unit circle 206 in a z-plane.
[0027] As will be understood by those skilled in the art, the poles are defined as values of z which make the denominator of the transfer function H(z) equal to 0; in other words:
[0000] 0=Σ j=0 Q a j z −j ,
[0000] where Q represents the IIR feedback filter order. Clearly, if a j is not equal to zero, then the poles are not located at the origin of the z-plane. This is in contrast to the FIR filter where all poles are located at the origin, and thus the ZFIR filter is always stable.
[0028] As previously stated, a significant disadvantage of a conventional BIIR filter implementation in a vector processor environment is a requirement for sequential processing of output samples. Conventional BIIR filter implementations utilize only a small subset (e.g., three) of the total number of multipliers available (e.g., 16). This implementation is inefficient, is prone to execution stalls, and is therefore undesirable.
[0029] As seen in equation (2) above, there is a direct correlation between the calculation of previous sample y[n−1] and output sample y[n]. Assume the BIIR filter is implemented in hardware (e.g., a vector processor) that is operative to execute several multiply accumulate (MAC) operations in a single cycle (e.g., 16 multipliers in the case of LSI vector processor VP16, or 32 multipliers in the case of CEVA-XC323, commercially available from CEVA, Inc., Mountain View, Calif.). Execution problems associated with this approach are illustrated in conjunction with FIG. 3 .
[0030] By way of example only and without loss of generality, FIG. 3 is a conceptual view depicting three consecutive processor cycles, namely, cycles T, T+1 and T+2, along with exemplary operations performed during each of the cycles in a direct implementation of the illustrative BIIR filter. The duration of each cycle in absolute time is not critical to the invention and is therefore not explicitly shown. With reference to FIG. 3 , in cycle T, the following illustrative calculations are performed:
[0000] y[n− 1 ]=a 1 *y[n− 2]+Temp1 [n− 1]+Temp2 [n− 1];
[0000] Temp1 [n]=−a 2 *y[n− 2];
[0000] Temp2 [n]=A*x[n].
[0000] In cycle T+1, the following illustrative calculations are performed:
[0000] y[n]=−a 1 *y[n− 1]+Temp1 [n ]+Temp2 [n];
[0000] Temp1 [n+ 1 ]=−a 2 *y[n− 1];
[0000] Temp2 [n+ 1 ]=A*x[n+ 1].
[0000] Likewise, in cycle T+2, the following illustrative calculations are performed:
[0000] y[n+ 1 ]=−a 1 *y[n ]+Temp1 [n+ 1]+Temp2 [n+ 1];
[0000] Temp1 [n+ 2 ]=−a 2 *y[n];
[0000] Temp2 [n+ 2 ]=A*x[n+ 2].
[0031] As seen from the above operations, direct implementation of a standard BIIR utilizes only three multipliers out of all available multipliers during any given processor cycle. Most modern vector processors include a substantially greater number of available multipliers (e.g., 16, in the illustrative case of a VP16 vector processor), and thus a standard BIIR implementation utilizing only three multipliers in a given cycle results in an inefficient approach, at least in terms of resource allocation. In addition, this direct implementation of the BIIR filter can cause execution stalls in every cycle if MAC (i.e., multiply accumulate) operations are performed in more than one pipe stage, which is a practical scenario. Thus, for efficiency purposes, it would be desirable to implement the BIIR filter (or alternative BIIR system) in a manner which beneficially utilizes all, or at least a larger subset, of the available multipliers in a given vector processor system.
[0032] In order to achieve greater processing efficiency and speed, among other advantages, embodiments of the invention provide an implementation of the BIIR filter that beneficially eliminates the above-noted dependency between y[n] and y[n−1] samples. Additionally, the novel transformation methodology preserves the stability and accuracy of the BIIR filter. While embodiments of the invention are described herein with specific reference BIIR filters, it will become apparent to those skilled in the art given the teachings herein that techniques of the invention are applicable to IIR systems in general. Additional systems that can be modified according to embodiments of the invention include, but are not limited to, generally any auto-regressive moving-average (ARMA) system. A BIIR filter represents merely one simple illustration which achieves significant benefits over conventional approaches.
[0033] As previously stated, a standard BIIR filter can be represented by at least one of the following expressions:
[0000]
H
(
z
)
=
A
1
+
a
1
z
-
1
+
a
2
z
-
2
=
A
(
1
-
b
1
z
-
1
)
(
1
-
b
2
z
-
1
)
=
A
(
1
-
(
R
b
+
I
b
)
z
-
1
(
1
-
(
R
b
+
I
b
)
z
-
1
y
[
n
]
=
-
a
1
y
[
n
-
1
]
-
a
2
y
[
n
-
2
]
,
[0000] where a 1 and a 2 are filter coefficients, which are typically real numbers, b 1 and b 2 are respective locations of the filter poles, which are typically complex numbers (b 1 =R b +I b and b 2 =R b −I b ), y[n] is the calculated filter output, and y[n−1] and y[n−2] are previously calculated filter outputs. It is to be appreciated that, although aspects of the invention are described herein with reference to a second order BIIR filter, the invention is not limited to any specific filter order. Rather, techniques of the invention can be applied to BIIR systems other than second order, as will become apparent to those skilled in the art given the teachings herein.
[0034] In accordance with an embodiment of the invention, both the numerator and denominator of the transfer function H(z) shown in equation (2) are multiplied by (1+b 1 z −1 )*(1+b 2 z −1 ) in the following manner:
[0000]
H
(
z
)
=
A
(
1
+
b
1
z
-
1
)
(
1
+
b
2
z
-
1
)
(
1
-
b
1
z
-
1
)
(
1
-
b
2
z
-
1
)
(
1
+
b
1
z
-
1
)
(
1
+
b
2
z
-
1
)
H
(
z
)
=
A
(
1
+
(
b
1
+
b
2
)
z
-
1
+
b
1
b
2
z
-
2
)
(
1
-
b
1
2
z
-
2
)
(
1
-
b
2
2
z
-
2
)
H
(
z
)
=
A
(
1
+
(
b
1
+
b
2
)
z
-
1
+
b
1
b
2
z
-
2
)
(
1
-
b
1
2
+
b
2
2
)
z
-
2
+
b
1
2
b
2
2
z
-
4
(
5
)
[0000] Letting p 1 =A(b 1 +b 2 ), p 2 =A(b 1 *b 2 ), q 1 =−(b 1 2 +b 2 2 ), and q 2 =(b 1 2 *b 2 2 ), and substituting p 1 , p 2 , q 1 and q 2 into equation (5) above, the following expression for the transfer function H(z) of the transformed BIIR filter is obtained:
[0000]
H
(
z
)
=
A
+
p
1
z
-
1
+
p
2
z
-
2
1
+
q
1
z
-
2
+
q
2
z
-
4
(
6
)
[0000] Equation (6) above can be rewritten in regression equation form as follows:
[0000] y[n]=−q 1 y[n− 2 ]−q 2 y[n− 4 ]+Ax[n]+p 1 x[n− 1 ]+p 2 x[n− 2] (7)
[0035] In a z-transform plane, the illustrative transformed BIIR filter represented by equation (7) comprises four poles and two zeros. To ensure that the transformed BIIR filter is stable, all poles must reside within the boundary of a unit circle, as previously stated. FIG. 4 is a graphical illustration depicting pole and zero locations for the exemplary transformed BIIR filter, according to an embodiment of the invention. The transformed BIIR filter is represented in the z-plane as having four poles, namely, a first pole 402 , a second pole 404 , a third pole 406 and a fourth pole 408 , and two zeros, namely, a first zero 410 and a second zero 412 . As apparent from FIG. 4 , all poles 402 , 404 , 406 and 408 of the transformed BIIR filter have an absolute value smaller than one; i.e., all poles are located within the boundary of a unit circle 414 in the z-plane, thus satisfying the BIBO stability criterion.
[0036] As is seen in equation (7) above, there is no direct dependency between the calculation of samples y[n−1] and y[n]. A dependency exists only between the calculation of samples y[n−2] and y[n]. This approach provides enhanced calculation efficiency for a BIIR system compared to conventional methodologies.
[0037] By way of example only and without loss of generality, FIG. 5 is a conceptual view depicting two consecutive processor cycles, namely, cycles T and T+1, along with exemplary operations performed during each of the cycles in an implementation of an illustrative transformed BIIR filter, according to an embodiment of the invention. The duration of each cycle in absolute time is not critical to the invention and is therefore not explicitly shown. With reference to FIG. 5 , in cycle T, the following illustrative calculations are performed:
[0000] y[n− 2 ]=−q 1 *y[n− 4]+Temp1 [n− 2]+Temp2 [n− 2]+Temp3 [n− 2]+Temp4 [n− 2];
[0000] y[n− 1 ]=−q 1 *y[n− 3]+Temp1 [n− 1]+Temp2 [n− 1]+Temp3 [n− 1]+Temp4 [n− 1];
[0000] Temp1 [n]=−q 1 *y[n− 4];
[0000] Temp2 [n]=A*x[n];
[0000] Temp3 [n]=p 1 *x[n− 1];
[0000] Temp4 [n]=p 2 *x[n− 2];
[0000] Temp1 [n+ 1 ]=−q 2 *y[n− 3];
[0000] Temp2 [n+ 1 ]=A*x[n+ 1];
[0000] Temp3 [n+ 1 ]=p 1 *x[n];
[0000] Temp4 [n+ 1 ]=p 2 *x[n− 1].
[0000] In cycle T+1, the following illustrative calculations are performed:
[0000] y[n]=−q 1 *y[n− 2]+Temp1 [n ]+Temp2 [n ]+Temp3 [n ]+Temp4 [n];
[0000] y[n+ 1 ]=−q 1 *y[n− 1]+Temp1 [n+ 1]+Temp2 [n+ 1]+Temp3 [n+ 1]+Temp4 [n+ 1];
[0000] Temp1 [n+ 2 ]=−q 2 *y[n− 2];
[0000] Temp2 [n+ 2 ]=A*x[n+ 2];
[0000] Temp3 [n+ 2 ]=p 1 *x[n+ 1];
[0000] Temp4 [n+ 2 ]=p 2 *x[n];
[0000] Temp1 [n+ 3 ]=−q 2 *y[n− 1];
[0000] Temp2 [n+ 3 ]=A*x[n+ 3];
[0000] Temp3 [n+ 3 ]=p 1 *x[n+ 2];
[0000] Temp4 [n+ 3 ]=p 2 *x[n+ 1].
[0038] As seen from the above operations, implementation of the transformed BIIR filter utilizes ten multipliers during each processor cycle (one multiplier corresponding to each multiplication operation in a given processor cycle). The transformed BIIR approach thus advantageously improves calculation efficiency of the BIIR filter by about two times compared to a direct implementation of the BIIR filter shown in FIG. 3 .
[0039] FIG. 6 is a block diagram depicting at least a portion of an exemplary BIIR filter 600 , according to an embodiment of the present invention. BIIR filter 600 is a functional implementation of the transformed BIIR filter represented by equation (7) above. More particularly, input sample x[n] is multiplied in block 602 , which may be a scaling (e.g., attenuation or amplification) block, by a coefficient (i.e., constant) A to generate the signal Ax[n] supplied to a first summation block 604 . Concurrently, the input sample x[n] is fed to a first delay line 606 , which may be an input delay line, which includes first and second delay blocks 608 and 610 , respectively, connected together in series. The first delay block 608 , which has a delay D 1 associated therewith, is operative to generate a delayed input sample x[n−1] which is multiplied in block 612 by a coefficient p 1 to generate the signal p 1 x[n−1] supplied to a second summation block 614 . The second delay block 610 , which has a delay D 2 associated therewith, is operative to generate a delayed input sample x[n−2] which is multiplied in block 616 by a coefficient p 2 to generate the signal p 2 x[n−2] supplied to the second summation block 614 . It is to be appreciated that the respective delays D 1 and D 2 associated with delay blocks 608 and 610 , respectively, may be the same or different relative to one another, and the invention is not limited to any specific value of each delay. An output, p 1 x[n−1]+p 2 x[n−2], generated by summation block 614 is fed to summation block 604 where it is added to the signal Ax[n].
[0040] The output sample y[n] generated by summation block 604 is fed to a second delay line 618 , which maybe an output delay line. Delay line 618 includes a third delay block 620 having a delay D 3 associated therewith, a fourth delay block 622 having a delay D 4 associated therewith, a fifth delay block 624 having a delay D 5 associated therewith, and a sixth delay block 626 having a delay D 6 associated therewith. Delay block 620 is operative to generate a first delayed output sample y[n−1], delay block 622 is operative to generate a second delayed output sample y[n−2], delay block 624 is operative to generate a third delayed output sample y[n−3], and delay block 626 is operative to generate a fourth delayed output sample y[n−4].
[0041] The output sample y[n−2] generated by delay block 622 is multiplied in block 628 by a coefficient q 1 to generate a signal q 1 y[n−2] which is then supplied to a third summation block 630 via a first feedback signal path. Concurrently, the output sample y[n−4] generated by delay block 626 is multiplied in block 632 by a coefficient q 2 to generate a signal q 2 y[n−4] which is supplied to summation block 630 via a second feedback signal path. An output, q 1 y[n−2]+q 2 y[n−4], generated by summation block 630 is fed to summation block 604 where it is subtracted from the signal Ax[n]+p 1 x[n−1]+p 2 x[n−2] to generate the expression for the output sample y[n]=−q 1 y[n−2]−q 2 y[n−4]+Ax[n]+p 1 x[n−1]+p 2 x[n−2], as shown in equation (7). As will become apparent to those skilled in the art given the teachings herein, at least one of the first and second delay lines is preferably implemented using at least one shift register, digital signal processor and/or tapped delay line, although the invention is not limited to any specific delay line implementation.
[0042] The BIIR transformation according to embodiments of the invention described above can be extended in a general sense such that a dependency exists only between the calculation of samples y[n] and y[n−2 k ], where k is a natural number. If multiply operations are performed in several pipeline stages, a higher degree of decoupling between samples can provide greater calculation efficiency. In a general case, in order to obtain a transformed BIIR filter transfer function H(z) of stage N, a transformation of stage N−1 is preferably multiplied by the following expression:
[0000]
(
1
+
b
1
N
z
-
N
)
(
1
+
b
2
N
z
-
N
)
(
1
+
b
1
N
z
-
N
)
(
1
+
b
2
N
z
-
N
)
,
(
8
)
[0000] where N is an integer greater than or equal to two. As will become apparent to those skilled in the art given the teachings herein, it is straightforward to show that the expression set forth in equation (8) above adds poles inside the unit circle, and thus satisfies the BIBO stability criterion of the BIIR filter.
[0043] By way of example only and without loss of generality, assuming it is desired to extend the expression above to handle possible pipeline stalls, stage 2 of the novel BIIR transformation is calculated by inserting N=2 in equation (8) to yield the following expression:
[0000]
(
1
+
b
1
2
z
-
2
)
(
1
+
b
2
2
z
-
2
)
(
1
+
b
1
2
z
-
2
)
(
1
+
b
2
2
z
-
2
)
,
(
9
)
[0000] Both the numerator and denominator of the transfer function H(z) shown in equation (1) are multiplied by the expression in equation (9) to yield the following derivation:
[0000]
H
(
z
)
=
A
(
1
+
b
1
z
-
1
)
(
1
∓
b
2
z
-
1
)
(
1
-
b
1
2
z
-
2
)
(
1
-
b
z
2
z
-
2
)
=
A
(
1
+
b
1
z
-
1
)
(
1
∓
b
2
z
-
1
)
(
1
+
b
1
2
z
-
2
)
(
1
+
b
2
2
z
-
2
)
(
1
-
b
1
2
z
-
2
)
(
1
-
b
2
2
z
-
2
)
(
1
+
b
1
2
z
-
2
)
(
1
+
b
2
2
z
-
2
)
H
(
z
)
=
A
+
c
1
z
-
1
+
c
2
z
-
2
+
c
3
z
-
3
+
c
4
z
-
4
+
c
5
z
-
5
+
c
6
z
-
6
1
+
d
1
z
-
4
+
q
2
z
-
8
,
(
10
)
[0000] where c 1 =A(b 1 +b 2 ), c 2 =A(b 1 2 +b 1 b 2 +b 2 2 ), c 3 =A(b 1 3 +b 1 2 b 2 +b 1 b 2 2 +b 2 3 ), c 4 =A(b 1 3 b 2 +b 1 2 b 2 2 +b 1 b 2 3 ), c 5 =A(b 1 3 b 2 2 +b 1 2 b 2 3 ), c 6 =A(b 1 3 b 2 3 ), d 1 =−(b 1 2 +b 2 2 ), and q 2 =(b 1 2 *b 2 2 ) in equation (10) above. Equation (10) can be rewritten in regression form as follows:
[0000] y[n]=−d 1 y[n− 4 ]−q 2 y[n− 8 ]+Ax[n]+c 1 x[n− 1 ]+c 2 x[n− 2 ]+c 3 x[n− 3 ]+c 4 x[n− 4 ]+c 5 x[n− 5 ]+c 6 x[n− 6] (11)
[0044] FIG. 7 is a graphical illustration depicting pole locations for the exemplary transformed BIIR filter of equation (11), according to another embodiment of the invention. It can be easily shown that in the z-transform plane, the transformed BIIR filter in equation (11) will be represented as eight poles and six zeros, all poles being located within the boundary of the unit circle. With reference to FIG. 7 , a first pole 702 is located at a position of R b on the real axis and I b on the imaginary axis, a second pole 704 is located at a position of R b on the real axis and −I b on the imaginary axis, a third pole 706 is located at a position of R b 2 on the real axis and I b 2 on the imaginary axis, a fourth pole 708 is located at a position of R b 2 on the real axis and I b 2 on the imaginary axis, a fifth pole 710 is located at a position of −R b 2 on the real axis and I b 2 on the imaginary axis, a sixth pole 712 is located at a position of −R b 2 on the real axis and I b 2 on the imaginary axis, a seventh pole 714 is located at a position of −R b on the real axis and I b on the imaginary axis, an eighth pole 716 is located at a position of −R b on the real axis and −I b on the imaginary axis, a first zero 718 is located at a position of −R b on the real axis and I b on the imaginary axis, a second zero 720 is located at a position of −R b on the real axis and −I b on the imaginary axis, a third zero 722 is located at a position of −R b 2 on the real axis and I b 2 on the imaginary axis, a forth zero 724 is located at a position of −R b 2 on the real axis and I b 2 on the imaginary axis, a fifth zero 726 is located at a position of R b 2 on the real axis and I b 2 on the imaginary axis, and a sixth zero 728 is located at a position of R b 2 on the real axis and I b 2 on the imaginary axis. As shown, the respective locations of all poles lie within the boundary of a unit circle 730 , which is a fundamental requirement of any IIR filter since it assures filter stability.
[0045] FIG. 8 is a block diagram depicting at least a portion of an exemplary BIIR filter circuit 800 , according to another embodiment of the present invention. BIIR filter 800 is a functional implementation of the transformed BIIR filter represented by equation (11) above. More particularly, input sample x[n] is multiplied in block 802 by a coefficient (i.e., constant) A to generate the signal Ax[n] supplied to a first summation block 804 . Concurrently, the input sample x[n] is fed to a first delay line 806 , which may be an input delay line, which includes a plurality of delay blocks (first through sixth) 808 , 810 , 812 , 814 , 816 and 818 connected together in series. The first delay block 808 , which has a delay D 1 associated therewith, is operative to generate a delayed input sample x[n−1] which is multiplied in block 820 by a coefficient c 1 to generate the signal c 1 x[n−1] supplied to a second summation block 822 . The second delay block 810 , which has a delay D 2 associated therewith, is operative to generate a delayed input sample x[n−2] which is multiplied in block 824 by a coefficient c 2 to generate the signal c 2 x[n−2] supplied to a third summation block 826 . The third delay block 812 , which has a delay D 3 associated therewith, is operative to generate a delayed input sample x[n−3] which is multiplied in block 828 by a coefficient c 3 to generate the signal c 3 x[n−3] supplied to a fourth summation block 830 . The fourth delay block 814 , which has a delay D 4 associated therewith, is operative to generate a delayed input sample x[n−4] which is multiplied in block 832 by a coefficient c 4 to generate the signal c 4 x[n−4] supplied to a fifth summation block 834 . The fifth delay block 816 , which has a delay D 5 associated therewith, is operative to generate a delayed input sample x[n−5] which is multiplied in block 836 by a coefficient c 5 to generate the signal c 5 x[n−5] supplied to a sixth summation block 838 . The sixth delay block 818 , which has a delay D 6 associated therewith, is operative to generate a delayed input sample x[n−6] which is multiplied in block 840 by a coefficient c 6 to generate the signal c 6 x[n−6] supplied to the sixth summation block 838 .
[0046] It is to be appreciated that the respective delays D 1 through D 6 associated with delay blocks 808 through 818 , respectively, may be the same or different relative to one another, and the invention is not limited to any specific value of each delay. An output, c 1 x[n−1]+c 2 x[n−2]+c 3 x[n−3]+c 4 x[n−4]+c 5 x[n−5]+c 6 x[n−6], generated by summation block 822 is fed to summation block 804 where it is added to the signal Ax[n].
[0047] The output sample y[n] generated by summation block 804 is fed to a second delay line 842 , which maybe an output delay line. Delay line 842 includes a first delay block 844 having a delay D 1 associated therewith, a second delay block 846 having a delay D 2 associated therewith, a third delay block 848 having a delay D 3 associated therewith, a fourth delay block 850 having a delay D 4 associated therewith, a fifth delay block 852 having a delay D 5 associated therewith, a sixth delay block 854 having a delay D 6 associated therewith, a seventh delay block 856 having a delay D 7 associated therewith, and an eighth delay block 858 having a delay D 8 associated therewith. Delay block 844 is operative to generate a first delayed output sample y[n−1], delay block 846 is operative to generate a second delayed output sample y[n−2], delay block 848 is operative to generate a third delayed output sample y[n−3], delay block 850 is operative to generate a fourth delayed output sample y[n−4], delay block 852 is operative to generate a fifth delayed output sample y[n−5], delay block 854 is operative to generate a sixth delayed output sample y[n−6], delay block 856 is operative to generate a seventh delayed output sample y[n−7], and delay block 858 is operative to generate an eighth delayed output sample y[n−8].
[0048] The output sample y[n−4] generated by delay block 850 is multiplied in block 860 by a coefficient d 1 to generate a signal d 1 y[n−4] which is then supplied to a seventh summation block 860 via a first feedback signal path. Concurrently, the output sample y[n−8] generated by delay block 858 is multiplied in block 864 by a coefficient q 2 to generate a signal q 2 y[n−8] which is supplied to summation block 862 via a second feedback signal path. An output, d 1 y[n−4]+q 2 y[n−8], generated by summation block 862 is fed to summation block 804 where it is subtracted from the signal Ax[n]+c 1 x[n−1]+c 2 x[n−2]+c 3 x[n−3]+c 4 x[n−4]+c 5 x[n−5]+c 6 x[n−6] to generate the expression for the output sample y[n]=−d 1 y[n−4]−q 2 y[n−8]+Ax[n]+c 1 x[n−1]+c 2 x[n−2]+c 3 x[n−3]+c 4 x[n−4]+c 5 x[n−5]+c 6 x[n−6], as shown in equation (11). As will become apparent to those skilled in the art given the teachings herein, at least one of the first and second delay lines is preferably implemented using at least one shift register, digital signal processor and/or tapped delay line, although the invention is not limited to any specific delay line implementation.
[0049] The BIIR filter transformation defined in equations (10) and (11) above, and shown in FIGS. 7 and 8 , utilizes nine multipliers per output and enables four output calculations to be performed concurrently (i.e., in parallel). Thus, assuming operation in a vector processor environment with sixteen multipliers and two pipeline stages for multiplier calculations, the above transformation achieves a throughput of 16/9=1.78 output samples per cycle, compared to ½=0.5 sample per cycle achieved using a standard BIIR filter implementation. In this exemplary embodiment, therefore, performance is advantageously improved by 1.78/0.5=3.56 times.
[0050] One or more embodiments of the invention or elements thereof may be implemented in the form of an article of manufacture including a machine readable medium that contains one or more programs which when executed implement such method step(s); that is to say, a computer program product including a tangible computer readable recordable storage medium (or multiple such media) with computer usable program code stored thereon in a non-transitory manner for performing the method steps indicated. Furthermore, one or more embodiments of the invention or elements thereof can be implemented in the form of an apparatus including a memory and at least one processor (e.g., vector processor) that is coupled with the memory and operative to perform, or facilitate the performance of, exemplary method steps.
[0051] As used herein, “facilitating” an action includes performing the action, making the action easier, helping to carry out the action, or causing the action to be performed. Thus, by way of example only and not limitation, instructions executing on one processor might facilitate an action carried out by instructions executing on a remote processor, by sending appropriate data or commands to cause or aid the action to be performed. For the avoidance of doubt, where an actor facilitates an action by other than performing the action, the action is nevertheless performed by some entity or combination of entities.
[0052] Yet further, in another aspect, one or more embodiments of the invention or elements thereof can be implemented in the form of means for carrying out one or more of the method steps described herein; the means can include (i) hardware module(s), (ii) software module(s) executing on one or more hardware processors, or (iii) a combination of hardware and software modules; any of (i)-(iii) implement the specific techniques set forth herein, and the software modules are stored in a tangible computer-readable recordable storage medium (or multiple such media). Appropriate interconnections via bus, network, and the like can also be included.
[0053] Embodiments of the invention may be particularly well-suited for use in an electronic device or alternative system (e.g., communications system). For example, FIG. 9 is a block diagram depicting at least a portion of an exemplary processing system 900 formed in accordance with an embodiment of the invention. System 900 , which may represent, for example, a BIIR system or a portion thereof, may include a processor 910 , memory 920 coupled with the processor (e.g., via a bus 950 or alternative connection means), as well as input/output (I/O) circuitry 930 operative to interface with the processor. The processor 910 may be configured to perform at least a portion of the functions of the present invention (e.g., by way of one or more processes 940 which may be stored in memory 920 ), illustrative embodiments of which are shown in the previous figures and described herein above.
[0054] It is to be appreciated that the term “processor” as used herein is intended to include any processing device, such as, for example, one that includes a CPU and/or other processing circuitry (e.g., digital signal processor (DSP), network processor, microprocessor, etc.). Additionally, it is to be understood that a processor may refer to more than one processing device, and that various elements associated with a processing device may be shared by other processing devices. For example, in the case of BIIR filter circuit 600 shown in FIG. 6 , each of the delay elements 608 , 610 , 620 , 622 , 624 and 626 may be implemented in parallel (i.e., concurrently) using a separate corresponding DSP core, as in a distributed computing configuration. The term “memory” as used herein is intended to include memory and other computer-readable media associated with a processor or CPU, such as, for example, random access memory (RAM), read only memory (ROM), fixed storage media (e.g., a hard drive), removable storage media (e.g., a diskette), flash memory, etc. Furthermore, the term “I/O circuitry” as used herein is intended to include, for example, one or more input devices (e.g., keyboard, mouse, etc.) for entering data to the processor, and/or one or more output devices (e.g., display, etc.) for presenting the results associated with the processor.
[0055] Accordingly, an application program, or software components thereof, including instructions or code for performing the methodologies of the invention, as described herein, may be stored in a non-transitory manner in one or more of the associated storage media (e.g., ROM, fixed or removable storage) and, when ready to be utilized, loaded in whole or in part (e.g., into RAM) and executed by the processor. In any case, it is to be appreciated that at least a portion of the components shown in the previous figures may be implemented in various forms of hardware, software, or combinations thereof (e.g., one or more DSPs with associated memory, application-specific integrated circuit(s) (ASICs), functional circuitry, one or more operatively programmed general purpose digital computers with associated memory, etc). Given the teachings of the invention provided herein, one of ordinary skill in the art will be able to contemplate other implementations of the components of the invention.
[0056] At least a portion of the techniques of the present invention may be implemented in an integrated circuit. In forming integrated circuits, identical die are typically fabricated in a repeated pattern on a surface of a semiconductor wafer. Each die includes a device described herein, and may include other structures and/or circuits. The individual die are cut or diced from the wafer, then packaged as an integrated circuit. One skilled in the art would know how to dice wafers and package die to produce integrated circuits. Integrated circuits so manufactured are considered part of this invention.
[0057] An integrated circuit in accordance with the present invention can be employed in essentially any application and/or electronic system in which BIIR systems may be employed. Suitable systems for implementing techniques of the invention may include, but are not limited to, mobile phones, personal computers, wireless communication networks, etc. Systems incorporating such integrated circuits are considered part of this invention. Given the teachings of the invention provided herein, one of ordinary skill in the art will be able to contemplate other implementations and applications of the techniques of the invention.
[0058] Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made therein by one skilled in the art without departing from the scope of the appended claims. | A BIIR system includes a first delay line for receiving at least one input data sample and generating delayed input samples as a function of the input data sample. The BIIR system further includes a second delay line including multiple delay elements connected in series for generating delayed output samples. An input of one of the delay elements receives at least one output data sample of the BIIR system. A summation element in the BIIR system generates the output data sample of the BIIR system as a function of an addition of at least first and second signals and a subtraction of at least a third signal. The third signal includes a first delayed output sample generated by the second delay line multiplied by a first prescribed value. The first delayed output sample and the output data sample are temporally nonadjacent to one another. | 7 |
FIELD OF THE INVENTION
This invention relates to devices and methods to measure entrained and deposited solids in a fluid process system. More specifically, the invention provides an accurate suspended solids test for geothermal brine systems.
BACKGROUND OF THE INVENTION
Many industrial processes must handle fluids which also include solids in the form of entrained particles or precipitate (i.e., suspended solids). Due to temperature, pressure and other operating condition changes, these solids can deposit on the walls of the fluid process system in the form of scale, causing fluid handling problems and plug subsurface geothermal formations and injection wells. This can require special handling equipment (e.g., filtration) and special procedures, such as periodic back-flush or shutdown for solids removal and rework of injection wells. These added solids handling facilities and procedures can consume significant time, energy, and expense. In addition, facilities and procedures which are cost effective for one type and amount of solids may be ineffective for other types and amounts of solids, e.g., chemical cleaning can be quick and effective for removing a small amount of calcium carbonate-rich scale, but very costly (or even ineffective) for smaller amounts of carbonate in heavier scale deposits.
The ability to accurately forecast and/or measure solids in a fluid handling system (without shutting down the process) would minimize these handling problems and costs. Accurate forecast and measurements would allow optimization of solids removal efforts.
However, fluid process conditions (e.g., elevated temperature and pressure) can cause measurement problems. Limited fluid system access during production or other activities may also be a problem. These measurement problems have typically required sampling, rather than direct in-stream measurement. A typical sampling device is a Pitot tube which diverts a fluid (and suspended solids) to an ambient temperature and pressure collection device. The collected sample is then later analyzed in a laboratory.
In some process industries, such as geothermal energy extraction, these measurement difficulties are greatly compounded. The process fluid (brine) is saturated or supersaturated with scale-forming dissolved solids and acid gases. Usually, energy is extracted from geothermal brine by flashing to produce steam, which is then used to drive a steam drive. The flashing procedure, however, also lowers the pressure and temperature of the remaining geothermal brine which in turn tends to reduce solubility and supersaturate the dissolved solids and liberate gases. The supersaturated solids, liquids, and remaining gases may rapidly undergo chemical changes so that standard sampling and testing techniques generate erroneous results. For example, suspended solids measurement may erroneously include post-sampling precipitation. Still further, the scaling and rapid precipitation can clog or otherwise adversely affect sampling devices and methods.
A fluid sampling device has been developed by Battelle Memorial Institute for the U.S. Department of Energy at Pacific Northwest Laboratory. As disclosed in Technical Report No. PNL3412, UC66d, dated January 1980, Chapter 9 by R. P. Smith, the Battelle suspended solids sampling device is designed specifically for geothermal fluids. The device obtains a fluid and suspended solids sample in a Pitot tube-like probe and conduit. The sample conduit diverts the fluid sample out of the process flow stream to a heat exchanger to quickly cool the fluid (tending to stabilize the mixture by reducing the rapid rate of chemical reaction and precipitation). After cooling, the device filters the sample to remove the suspended solids. Any remaining liquid sample is then collected for laboratory analysis.
Although the rapid precipitation rate is reduced and suspended solids are removed by the Battelle sampling device, measurement problems remain. Diverting the suspended solids in the sample line may deposit suspended solids before collection and accelerate precipitation reactions. Sample cooling slows but does not stop precipitation. Sample cooling thermal gradients may also cause further deposition of the sampled suspended solids before filtration. Thus, even if the fluid (and entrained suspended solids) sample is initially representative, the sample quickly becomes unrepresentative.
Another measurement approach is to provide a process fluid side stream. The side stream is periodically isolated (without disturbing the main process system) and fluid samples or coupons removed for measurements. Coupons or other surfaces in the side stream are exposed to flowing brine to represent main process system surfaces under process conditions. After exposure to the coupons, the side stream fluids may be returned to the main stream or separately discharged.
However, side stream measurements have also been inaccurate. Side stream fluid conditions cannot fully duplicate main stream conditions. Diversion to the side stream may again cause unrepresentative scaling/precipitation. Although brine is flowing, side stream geometry is different (e.g., smaller side stream geometry can provide more pipe contact area for precipitation than main process stream). Flow distribution conditions are also different from the process stream. These differences can affect precipitation, scale formation and solids measurement.
Besides these problems, the suspended solids measurement device and method must also be able to handle a variety of process conditions. A sampled or side stream measurement may be nearly representative at certain fluid process conditions, but not at others, such as part load operation. The measurement device should also be capable of providing rapid measurements in response to changes in process conditions.
None of the current approaches known to the inventors eliminate the aforementioned side stream and sample collection problems. In addition, the problem of periodic solids removal from side stream or sampling apparatus remains.
SUMMARY OF THE INVENTION
Such problems are avoided in the present invention by providing a concurrent in-stream suspended solids measurement and liquids collection device. The device uses a first replaceable probe in a removable sampling device. Like the common Pitot tube, the present invention obtains a representative sample of fluid, but an in-stream filter at the sample entrance port immediately collects and removes suspended solids before significant additional precipitation or other chemical changes occur. The remaining liquid is quickly cooled under pressure and collected in non-scaling equipment. A real time indication of suspended solids is obtainable from a pressure drop measurement across the filter, in addition to removal and direct measurement of filtered solids.
The first probe can be replaced with a second probe inserted into the process stream. The second probe exposes a solids collection surface to collect scale. A real time estimate of scale can be obtained by drag force or pressure drop measurement, as well as direct measurement of the scaled probe. The in-stream sampling, redundant real time data, and initial separation of suspended solids result in accurate solids and other fluid measurements. The replaceable probe device also allows complementary fluid measurements further assuring accuracy.
The replaceable feature is achieved by mounting the probes to a movable shaft within an extension pressure containment pipe attached to a valved access to the process stream. The shaft is hollow to conduct the collected liquid sample to a collection vessel. The shaft moves from a sampling position (through opened access valve) to a withdrawn position (allowing access valve to be closed).
The process of using the removable assembly attaches the pipe to the valved process access port. The access valve is opened and the shaft translates the sample probe into the fluid process stream. After measurement and/or sample collection, the probe is withdrawn and access valve is closed. After venting, the probe can be removed and replaced with a different insertable probe. Corrosion probe can also be installed to measure the corrosion rate of the fluid handling system.
The present invention is expected to be accurate under off-design conditions because of the immediate separation of suspended solids, quick cooling under pressure to inhibit further precipitation (maintaining fluid chemistry), and multiple sample probe capability. The multiple probe ability provides redundancy and alternative property measurement capability.
The present apparatus and method achieves (1) accurate measurement of in-stream suspended solids, (2) accurate measurement of in-stream scaling rate, and (3) accurate measurement of in-stream corrosion rate. The in-stream measurements avoid errors caused by sample withdrawal or side stream diversions which change the condition of fluid and measured fluid and handling system properties.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic side view of a sampling apparatus having a solids filtering measurement probe; and
FIG. 2 shows a cross-sectional schematic view of a sampling assembly similar to that shown in FIG. 1 having a solids measurement probe for scaling or corrosion.
In these Figures, it is to be understood that like reference numerals refer to like elements or features.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic cross-sectional view of a solids filtering measurement apparatus 2 attached to a portion of a fluid handling system or process pipe 3. The pipe 3, handles a flow of elevated temperature fluid mixture or brine 4 (shown as an upstream fluid flow direction arrow within pipe 3) which includes suspended solids. In geothermal steam gathering or flash systems, the brine is also supersaturated in dissolved solids, such as silica and sulfide. The suspended solids and supersaturation at elevated temperatures generate ongoing precipitation of silica particulates and scale of the inside (fluid contacting) surfaces of the pipe 3. An opening 5 in a measuring device or sampling probe 6 opens to the upstream direction in order to obtain a fluid 4 sample within the probe 6. The sampling probe 6 portion of the solids measurement apparatus 2 is a tubular member attached at a sample probe mounting surface on hollow shaft 7 by union 8 (each of two union parts shown exploded for clarity) which diverts a fluid (and entrained suspended solids) sample out of the pipe 3. Proximate to the opening 5 is a filter or screen 9 for separating suspended solids which is held in place between the probe 6 and the mounting surface on hollow shaft 7 by the union 8. The sampling probe 6 may also include a scale testing material surface 10. Although the test material surface 10 is shown on the upstream facing surface, downstream or other surface or protrusions of the probe 6 in the stream flow may be used.
Alternative embodiments may place the filter 9 closer to the opening 5 or even in-line with the flow direction 4 (e.g., rotated 90 degrees and placed at the opening 5). However, since the probe assembly 6 must be insertable and withdrawable on shaft 7 through an access valve 11 when opened, valve limited in-line dimensions and placement may require placement of the filter 9 as shown.
The process stream access valve 11 is attached on one side to a process pipe tee or other process port 12 and a means for sealing and unsealing the port 12. Access valve 11 is preferably a gate or other full opening type of shutoff valve. A first coupling 13 attaches a fluid containment conduit or extension pipe 14 to the other side of access valve 11. The extension pipe 14 provides a length to withdraw shaft 7 and attached sample probe from the process stream 4 while containing the pressurized brine 4 when access valve 11 is open. Shaft 7 is within tee 12, open access valve 11 and extension pipe 14 when shaft 7 is in the sampling position as shown.
The protruding handle 16 attached to shaft 7 and the length of extension pipe 14 (from first coupling 13 to second coupling 15) allow the probe assembly 6 to be withdrawn into the extension pipe 14 when the shaft 7 is moved downwardly and out of the process pipe 3 to the withdrawn position (not shown). Movement (in a transverse direction) is accomplished by pulling (radially outward from fluid flow direction 4) or screwing on handle 16. The shaft 7 is slidably sealed by sheath or packing gland 17 near the handle 16. The sheath 17 is attached to a pressure control box 19 which is attached to the extension pipe 14 by the second coupling 15. Pressure in the annulus 18 between the walls of the box 19 and the shaft 7 is measured by one of two pressure gauges 20a. Fluid pressure in the box 19 can be vented through vent valve 21. If a pressurized fluid supply (not shown for clarity, but similar a source of pressure arrow shown leading to collection tubing 23) is attached downstream of the vent valve 21, the annulus 18 can be pressurized with inert gas such as nitrogen before opening access valve 11 when vent valve 21 is opened.
A first sample valve 22 is a control for the fluid sample pressure and flow through the sampling probe 6 and hollow shaft 7. The first sample valve 22 is attached to collection tubing 23 by union 24. The collection tubing 23 is preferably flexible to allow transverse motion of the shaft 7. Alternatively, rigid collection tubing 23 may be attached when the shaft is in one position and removed by disconnecting union 24 prior to changing the position of shaft 7. The collection tubing 23 includes a heat exchanger portion 25. As shown, this tubing portion 25 may be helical portion of collection tubing within a cooling vessel 26. The cooling vessel 26 may be filled with an ice bath (not shown) to cool the fluid sample within collection tubing 25. Other types of fluid heat exchangers may also be used.
A second sample valve 27 is a second control of the flow and pressure within the collection tubing 23. Second sample valve 27 is located downstream of the first sampling valve 22 proximate to a collection vessel 28. Pressure can be measured by a second pressure gauge 20b attached to the collection tubing 23. Although shown schematically as open vessels, the cooling and collection vessels 26 and 28 may be closed (pressurizable) fluid containers. The collection vessel 28 may be transported to a laboratory for measurement and analysis of the fluid sample.
FIG. 2 shows a cross-sectional schematic view of a similar sampling assembly 2a having replaced the fluid probe and hollow shaft. The brine flow direction 4 is again shown as an arrow within a fluid process handling system or pipe portion 3. The solids sampling probe 6a portion of the measurement apparatus 2a is either a solids collection or corrosion probe coupon attached at a sample probe mounting surface on solid shaft or arm 7a at joint 8a. The sampling probe 6a holds a solid or screen-like scale testing material surface 10a.
The first or process stream access valve 11 is attached on one side to a process pipe tee or other process port 12 and is preferably a gate or other full opening type of shutoff valve. A first coupling 13 attaches an extension pipe 14 to the other side of access valve 11. Solid shaft 7a is within tee 12, open access valve 11 and extension pipe 14 when shaft 7a is in the sampling position (as shown). The extension pipe 14 again provides a pressure containment for the brine 4 when access valve 11 is open.
The length of extension pipe 14 (from first coupling 13 to second coupling 15) allows the probe assembly 6a to be withdrawn into the extension pipe 14 when the solid shaft 7a is moved down and out of the process pipe 3. Movement (in a transverse direction) is again accomplished by manually pulling outward on handle 16. The handle 16 is attached to a protruding end of shaft 7a.
The shaft 7a is slidably sealed by sheath or packing gland 17a near the handle 16. The sheath 17a is adjustably (e.g., threadably) attached to the box 19. Packing material 29 is one means for allowing the shaft 7a to move transversely while containing the brine and may be composed of Teflon. Although heavy scaling is not expected at the end of the shaft near the packing, the shaft sliding contact with the packing is also a means of removing soft or loose scale on the shaft 7a (i.e., motion of shaft against packing tends to scrape off scale deposits on shaft 7a). Tightening (e.g., screwing) the sheath compresses the packing to seal the shaft 7a (preventing brine from leaking outside box 19) and also tends to removably secure the shaft 7a in place if sufficiently compressed. Other means for removably securing the shaft, such as a set screw, can also be used. An alternative means of sealing while allowing transverse motion is a piston in cavity 30.
Pressure in the annulus 18a between the walls of the box 19 and the shaft 7a is measured by pressure gauge 20. Fluid pressure in the box 19 can be vented through vent valve 21. If a pressurized fluid supply (not shown for clarity) is attached to the vent valve 21, the annulus 18a can also be pressurized prior to opening access valve 11.
The process of using the sampling apparatus (having either of the probes and shafts shown in FIGS. 1 and 2) is to assemble the apparatus (when access valve is closed) to access valve 11 with either the fluid sampling probe 6 or solid probe 6a attached to the shaft 7 or 7a. Solid probe 6a may also be attached to the hollow shaft 7 at the mounting surface if the sampling valve 22 or other sealing means is provided. Apparatus may also be pre-assembled. Second valve 21 is closed to form a fluid container.
To prevent oxidation of brine 4 and an unrepresentative surge of brine 4 into the sample conduit (hollow portion of the probe and shaft plus collection tubing) when the access valve 11 is opened, the sample conduit is first purged (valves 21 and 27 open) with and then pressurized (valve 21 and 27 closed through first sample valve 22 using an inert fluid pressure source, such as nitrogen (shown schematically as source of pressure arrow in FIG. 1). The annulus 18a may also be separately pressurized to a pressure comparable to the process stream through vent valve 21 before opening access valve 11 to the process stream if a pressure source (not shown) is attached downstream of vent valve 21. Heat exchanger 25 and vessel 26 may also be used to condition or change the temperature of the inert gas in the annulus 18 to avoid a thermal gradient.
The inert gas pressurization prevents exposure to air (oxidation) and flashing of the brine and also allows leakage testing to be accomplished. External (e.g., at couplings) and internal leakage (e.g., through vent valve 21) can be checked using a variety of known leak test means. Source of inert gas pressure is disconnected or otherwise isolated from the sampling apparatus when the apparatus is leak tested and pressurized.
When annulus and sample conduit inert gas pressure is comparable to the process stream and the source is isolated, first sample valve 22 and/or vent valve 21 is closed and access valve 11 is fully opened. Additional leak testing may also be accomplished at this point, if required. Handle 16 is used to push the shaft 7 or 7a and attached probe 6 or 6a into the process stream 4 through open access valve 11 and the shaft position secured by tightening sheath 17.
Suspended solids measurement may be desired when the brine feed stream 4 is flowing at various velocity distribution conditions. The transverse movement of shaft 7 allows placement of opening 5 at various locations across the pipe 3 diameter or at a single representative location. A preferred representative location of the opening 5 is at the center of the pipe 3. Similarly, a representative or traverse of locations of the solid probe 6a can be selected.
If a fluid sample is to be obtained using probe 6, first and second sample valves 22 and 27 are opened. Opening of these valves can be set to minimize the disturbance of the velocity profile within pipe 3. Sample velocity across opening 5 can approximate velocity prior to sample probe insertion, minimizing disturbance to velocity conditions in pipe 3. Hot process fluid flows through opening 5 and filter 9 prior to being cooled in heat exchanger portion 25 and discharged into collection vessel 28. When a sufficient fluid sample quantity is collected in collection vessel 28, one of the sample valves may be closed and collection vessel isolated.
During the fluid collection, the difference in pressure between the process stream pressure in pipe 3 and sample fluid pressure (e.g., as measured by the pressure gauge 20b attached to the collection tubing 23) can be used to determine the quantity of suspended solids collected by filter 9. An initial or baseline pressure difference, if any, is primarily a function of sample conduit pressure losses (e.g., shaft 6 pressure losses). Any further increase in pressure difference should primarily be caused by filter 9 accumulation of suspended solids (i.e., pressure loss across the loaded filter).
After exposure of coupon or test surfaces 10 or 10a and/or fluid sampling is completed, shaft 7 or 7a is unsecured and attached probe 6 or 6a is withdrawn from the process stream through access valve 11 and the access valve closed. Pressurized fluid brine within the annulus 18 or 18a and the sample conduit can be vented through vent valve 21 and purged with nitrogen using the inert gas supply, if present. First coupling 13 may then be safely disassembled and the probe removed. Removal of scale or other deposits may also be accomplished, if required. The probe may be replaced with a different type and material of construction and inserted as above.
The replaceable probe or corrosion coupon feature allows different samples to be collected or corrosion rate to be measured at the same point in the process stream. Different sample probes can be used to provide redundant measurements or to complement prior measurements. The removable feature also allows direct weighing of components (difference before and after exposure measures the weight of collected scale and suspended solids) without scraping and separate weighing.
In operation, the invention is expected to be used for short and long term exposures in the process stream. Fluid samples (and associated suspended solids measurements) can generally be obtained in less than one hour, preferably in less than 5 minutes. In contrast, scaling probes or corrosion coupons may be left exposed for days or months prior to withdrawal and direct measurement. Real time data and withdrawal decisions may also be based upon pressure loss across the sampling probe (i.e., pressure difference between upstream and downstream of probe locations within the process pipe 3), indicating scale quantity.
The invention satisfies the need to obtain real time and in-process stream measurements. Initial removal of suspended solids at nearly in-stream conditions, pressure difference measurements, repeatability, probe replacement ability and quick sampling avoid delayed, unrepresentative, and unreliable measurement problems of prior devices.
The invention allows accurate sampling during start-up, shutdown, steady state, and upset process conditions. Further advantages of the invention include: safety (leak testing and venting before direct access), reliability (redundant and complementary measurements), and maintenance (removal and disassembly allows easy cleaning).
Although the maximum and minimum temperature and pressure of the brine process stream are theoretically unlimited, the brine temperature is typically limited to a range of from near ambient to 320° C. preferably from about 100° C. to about 250° C. The geothermal brine pressure is typically within a range of about one atmosphere to 40 atmospheres, preferably from about one atmosphere to about 30 atmospheres.
The size of the sampling apparatus is also similarly theoretically unlimited. However, the access valve that is preferred is a 2.54 cm (1 inch) nominal full flow valve. Probe assemblies and shafts must have dimensions which allow passage through this size access valve.
Alternative embodiments allow different probes, such as corrosion coupons to be directly exposed and removed from the process stream. Other replaceable probes can be designed to measure fluid velocity, flow rate, density, or other fluid properties within the process stream. Still other probes could be designed to measure the properties of the filtered solids within the process stream, such as fiber optics or other detector means.
Still other alternative embodiments are possible. These include: a scraper mounted on the shaft 7 or 7a to better remove accumulated scale in the annulus when the shaft is moved; a plurality of openings (e.g., an annular type of device) in a fluid sample probe instead of the single fluid opening 5; an expandable or bendable probe which could sample at any point within the process pipe 3 and could be bendably or compressively withdrawn through the access valve; a series of openings 5 at different radial and axial positions along the shaft/probe so that shaft rotation would expose a series of openings to the flow direction 4 without replacement; a remotely operated valve at opening 5; a plurality of shafts and probes insertable upon access valve opening; adding a flexible washer to the shaft proximate to the wall 3 when in the sampling position to simulate the wall of the pipe 3; providing a mechanized means for moving the handle 16 and shaft 7 or 7a; having the fluid sample conduit (i.e., probe, shaft and collection tubing) be composed of or coated with non-scaling or scale resistant materials, such as Teflon reinforced materials; having components (e.g., extension pipe 14) be composed of transparent materials to observe position and scale buildup; connecting the collection tubing directly to an analysis instrument instead of a collection vessel 28 for later analysis; and insulating the external apparatus surfaces to reduce thermal gradients and losses.
While the preferred embodiment of the invention has been shown and described, and some alternative embodiments also shown and/or described, changes and modifications may be made thereto without departing from the invention. Accordingly, it is intended to embrace within the invention all such changes, modifications and alternative embodiments as fall within the spirit and scope of the appended claims. | In-stream suspended solids measurement in geothermal brine is accomplished by removal of suspended solids under process conditions followed by cooling using a detachable probe assembly. The cooling inhibits precipitation of added solids. By placing an in-stream filter at the sample entrance to immediately collect and remove suspended solids, pressure drop across the filter can be used to obtain real time suspended solids measurements. The filter may be composed of non-reactive/non-scaling materials and exposed for short durations to avoid additional chemical reaction and precipitation/scale at the filter. The detachable probe is attached to a valved access to the process stream allowing detachment and device weighing (instead of scale removal and weighing) to also provide suspended solids measurements. The assembly includes an extension pipe to contain the process stream pressures, a mounting for a Pitot tube or coupon on a translatable shaft or tube which can be translated through the valved access to the process stream, and a vent valve to seal and control pressure in the extension pipe. A fluid collection system includes a cooling surface and collection vessel. | 4 |
FIELD OF THE INVENTION
The present invention relates generally to the encapsulation of high intensity sweeteners for the purpose of stability in numerous food applications. In particular, it relates to the encapsulation of dipeptide sweeteners such as aspartame that possess greater stability and longer shelf life for use in chewing gum compositions.
BACKGROUND OF THE INVENTION
Whereas the dipeptide sweetener known as aspartame (alpha-L-aspartyl-L-phenyalanine methyl ester) or APM has revolutionized the low calorie food and beverage industries, the sweetener is not without its drawbacks. Of major significance is the sweetener's instability in the presence of heat, moisture and alkaline environments. This instability has prevented its use in most if not all cooking and baking applications and is a factor that must be considered in products that require a long shelf life. Many attempts have been made using different coatings and/or physical/mechanical processing parameters to increase the stability of APM for this purpose and yet there still is much room for improvement.
U.S. Pat. No. 4,384,004 to Cea et al discloses the encapsulation of APM with one or a number of different coatings consisting of cellulose, cellulose derivatives, vinyl polymers, gelatin, zein, waxes and mixtures thereof in a ratio of coating material to APM of 1:1 or less. The APM is coated by conducting the APM particles in a stream of air that passes through a zone of atomized liquid droplets of the coating material thereby forming discrete layers about the APM particles under substantially anhydrous conditions. The stabilized APM particles are particularly useful in chewing gum applications.
U.S. Pat. Nos. 4,122,195 and 4,139,639 to Bahoshy et al propose to "fix" APM by preparing it with a material such as gum arabic or the reaction product of a compound containing a polyvalent metallic ion, with an ungelatinized starch acid-ester of a substituted dicarboxyllic acid by a spray-drying technique wherein the APM and film former are prepared in an emulsion. While the technique reportedly shows some improvement in shelf stability, relatively rapid breakdown of the APM still occurs.
U.S. Pat. No. 4,828,857 to Sharma et al discloses a sweetener delivery system wherein the sweetener core material is formed in an agglomerate hydrophobic matrix by spray congealing. The agglomerated matrix is selected from the group consisting of waxes, fatty acids and mixtures thereof. The agglomerated sweetener is then given a second coating of these hydrophobic materials and lecithin is added as a wetting agent to increase the affinity of the fat or wax for the APM crystals. Chewing gum and boiled hard candy are specifically taught applications for the sweetener delivery system.
U.S. Pat. No. 4,722,845 to Cherukuri et al discloses a stable, cinnamon-flavored chewing gum composition wherein a dipeptide or amino acid sweetener is protected from reacting with the degradative aldehydes of the flavor oil by encapsulating the sweetener in a mixture of fat and high melting point (106°) polyethylene wax. The materials are coated onto the aspartame crystals using a modified spray congealing technique to form aggregated particles that may be mixed into the gum base for longer lasting shelf life stability.
U.S. Pat. No. 4,816,265 also to Cherukuri discloses chewing gum compositions containing APM that is encapsulated with a mixture of a low molecular weight polyvinyl acetate (PVA) and an emulsifier. The sweetener is blended into a homogeneous melted molten mass of PVA and the resultant mixture is a semi-solid mass which is cooled to a solid and ground into particles with a U.S. standard mesh size of 30 to about 200. The sweeteners are protected from adverse conditions such as moisture, PH, temperature and reactive chemicals such as flavor oils in the gums.
U.S. Pat. No. 4,704,288 to Tsau et al discloses a heat stabilized form of APM for baking applications. Aspartame is first granulated to particles with a U.S. mesh size of from about 8 to about 40 that are then coated with partially dehydrogenated vegetable oil. Both the type of fat and particle size are critical to the stability of the sweetener which may allegedly be used in cakes, cookies and other baked goods.
U.S Pat. No. 4,816,265 to Zibell discloses chewing gum with a delayed release, high potency sweetener such as aspartame. The APM is initially coated with modified cellulose such as hydroxypropyl methyl cellulose. The APM particles are then mixed with a zein solution with a pH of from 11.5 to 12.5. The damp mix is then dried to produce twice coated particles of the high intensity sweetener which allegedly enchance the shelf life stability of the sweetener and produce a delayed release of sweetness when this gum is chewed.
PCT Application No. PCT/US88/02398 also to Tsau discloses another heat stabilized form of APM wherein the dipeptide crystals are "spheronized" into dense, non-porous granules of substantially spherical shape within a narrow particle size range. The dense, spherical granules are preferably further encapsulated with a hydrophobic coating such as fats, starches, proteins and/or fibers and allegedly possess both stability against moisture, heat and acidic conditions as well as possessing a sustained release functionality for dispersion of the sweetener throughout the food matrix over time.
U.S. Pat. No. 4,588,612 to Perkins et al discloses the compaction of needle-like crystals of a material such as aspartame into a plurality of dense chips which are then ground to an average particle size of 20 to 400 standard U.S. mesh. The granules are then spread on a fluid bed spray reactor and encapsulated with a molten hydrogenated lipid or wax. The encapsulated aspartame granules are disclosed as being useful in baking applications since the encapsulating material essentially protects the granule from degradation that would otherwise result from the effects of heat and alkaline pH. The Perkins et al. invention is principally useful with water insoluble coatings which will allegedly protect the APM granules from moisture and heat that is present during baking.
It is an object of the present invention to provide a dipeptide sweetener composition with improved longer lasting shelf life stability. It is a further object of the present invention to provide a stabilized dipeptide sweetener that is compressed and encapsulated with a fat or wax coating in a 1:1 ratio to give it a long lasting shelf life stability. More particularly, it is an object of the present invention to provide an encapsulated compressed APM composition which, through dry granulation technology, possesses a longer lasting shelf life useful in chewing gum compositions where moisture, pH, and reactive flavor oils are adverse degradative factors.
SUMMARY OF THE INVENTION
The present invention is an improved dipeptide sweetener with longer lasting shelf life stability that is particularly useful in chewing gum compositions and especially useful in cinnamon-flavored chewing gum. The dipeptide sweetener is encapsulated through an anhydrous process that compresses the crystals within a mixture of inert binder ingredients so as to form a solid tablet or sheet which is then ground into a fine granular powder (40-60 U.S. Standard mesh). The compressed cores are then coated with a hydrophobic material such as either fat or wax resulting in a dipeptide sweetener with improved shelf life stability in the presence of otherwise adverse flavor oils and high processing temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a micrograph (100 x) of unprocessed aspartame powder showing its needle-like, dendritic crystals.
FIG. 2 is a micrograph (100 x) of the same aspartame powder in the shape of granular compacted cores produced after compression by the process of the present invention.
FIG. 3 is a Differential Scanning Colorimetry profile of the compacted APM core materials of the present invention.
FIG. 4 is a graph displaying the shelf life stability of the encapsulated aspartame compositions of the present invention in cinnamon gum as a function of percent APM remaining over time.
FIG. 5 is a graph comparing the shelf life stability of the coated core material with that of two coated aspartame samples of the prior art.
DETAILED DESCRIPTION OF THE INVENTION
The dipeptide sweetener compositions of the present invention are stabilized through a high pressure compaction process that imbeds the needle-like, dendritic crystal forms of aspartame into an anhydrous mixture of inert elements that further stabilize the sweetener from the adverse affects of temperature, moisture and reactive chemicals. Whereas the use of coatings such as fat, waxes, cellulose etc. have been used extensively in the past in an effort to protect materials such as aspartame from adverse conditions, the dendritic, needle-like shape of the crystals are highly irregular and difficult to impossible to coat in a complete and uniform manner. Moreover, even if the crystals were coated in their entirety, mechanical stresses and/or forces would inevitably break them off leading to exposed and unprotected APM at numerous places which is unsatisfactory.
The compositions of the present invention are comprised of a dipeptide sweetener such as aspartame, alitame and others. The sweetener is first combined in an anhydrous mixture or blend of a number of inert compounds which serve in a protective and binding capacity.
The amount of dipeptide sweetener used can vary depending upon the type of food application that it is used in and the degree of sweetness desired. The sweetener can comprise anywhere from 5-70% by weight of the core material, preferably 15-45% and most preferably 20-40% of the total weight of the core material. Cellulose, such as microcrystalline cellulose, is the major component of the core blend and can comprise anywhere from about 10% to about 90% by weight of the core and preferably 10%-60% and most preferably 20% to 30% of the total weight of the core material. This acts not only as a binder but produces protective functionality for the APM as a heat stabilizer as well as improved tabletting. Waxes and powdered cellulose also serve as suitable binding agents within the scope of the present invention.
A lubricity agent such as magnesium stearate, talc, mineral oil, stearic acid and the like is added to maximize the flow qualities of the anhydrous mixture prior to tabletting and also aids the compaction process as it prevents the APM granule from sticking to the compressor die. The lubricity agent comprises a deminimus portion of the encapsulated sweetener core and may be incorporated in the core in amounts of about 0.1-5.0%, preferably, about 0.5% to about 3.0% and most preferably from about 0.5%-1.0% is added to the anhydrous blend.
An inert material such as polyols, carbohydrates or calcium phosphates is added in a protective capacity to prevent the core sweetener material from reacting with certain constituents of the flavor oils and other chemicals. Cinnamon for example, contains aldehyde groups which react with the dipeptide and result in a loss of sweetness. Polyols suitable in the practice of the present invention include sorbitol, mannitol, xylitol or erythritol and are added in order to stabilize the dipeptide from the adverse conditions of heat, moisture and flavor oils. Mannitol is the polyol most preferred in the practice of the present invention in that it also improves the tabletting characteristics of the compressed granules. The polyols may be added to the anhydrous blend in amounts from 5.0%-80.0%, preferably 10%-50% and most preferably, 20% to 40% by weight is added to the blend. Carbohydrates such as polydextrose and palatinit as well as mono-, di- and tri-calcium phosphate also serve as suitable inert protective materials.
Finally, a non-sticking agent such as colloidol silicon dioxide (SiO 2 ) is added to the anhydrous blend to aid in the compaction/tabletting process and to prevent the caking or sticking of the aspartame particles. This component is added in relatively minor amounts and may consist of from 0.1%-3.0% by weight of the core composition, preferably 0.5%-2.0% and most preferably 1.0%-2.0%.
All of the ingredients are mixed under anhydrous conditions in a twin shell dry blender (Model LB-832, Patterson-Kelly Co., East Stroudsburg, PA) for ten (10) minutes. The mixed powder composition is fed into a compression tablet machine (Stokes Model B-3) and compressed into sweetener tablets of at least 200 newton. Preferably, the tablet is "slugged" (percompression or double-compression method). Regardless of the manner in which the powdered sweetener composition is compacted, the tablets or slugs are then milled using a Eureka TG2S grinder into granules or particle cores of about 30-45 mesh (350-590 microns) and coated. (See FIG. 2)
The compacted APM granules may then be coated with a fat such as animal fat, vegetable fat, waxes, cellulose, or mixtures thereof. This is readily achievable despite the non-uniformity of the particle size shape. Preferably, the particles are coated with a mixture of partially hydrogenated soybean oil and glycerol monostearate. Whereas the soybean oil may consist of from about 60% to about 99% and most preferably of from about 90% to about 98% by weight of the entire coating composition, the glycerol monostearate may be incorporated in amounts of from about 0.5% to about 80% and preferably of from about 0.5% to about 20%.
The coating process may be carried out using a standard fluidized bed coating apparatus such as the Verse Glatt Fluid Bed Agglomerator/Dryer Model GPCG-1 (Glatt Air Techniques, Inc., Ramsey, NJ). The compressed APM particle cores are suspended in an air stream and sprayed with the molten fat composition as it is passed through a compressed air nozzle as atomized particles and gradually coats the APM cores. The amount of coating applied to the core is preferably no more than a 1:1 APM core/fat ratio and may be applied as discrete layers during the fluidization process.
Whereas the encapsulated dipeptide sweetener may be used in many applications where long shelf life is a consideration and conditions such as reactive flavor ingredients, temperature, moisture and pH of the food matrix present a hostile or degradative environment, the present inventions is particularly useful in the incorporation in chewing gum and most particularly, cinnamon chewing gums wherein aldehyde components of the flavor oil react with the dipeptide sweeteners causing diketopiperazine formation. However, as FIG. 3 clearly shows, the APM granules of the present invention are also stable in the presence of high temperatures. The absence of any peaks in the Differential Scanning Colorimetry (DSC) Profile is indicative of no phase changes occurring in the APM granules even when heated to 100° C. The surprising and unexpected stability at these high temperatures make the granules of the present invention suitable for baking applications.
With regard to the chewing gum formulations in which the novel delivery system is employed, the amount of gum base employed will vary greatly depending on various factors such as the type of base used, consistency desired and other components used to make the final product. In general, amounts of about 5% to about 45% by weight of the final chewing gum composition are acceptable for use in chewing gum composition with preferred amounts of about 15% to about 25% by weight. The gum base may be any water-insoluble gum base well known in the art. Illustrative examples of suitable polymers in gum bases include both natural and synthetic elastomers and rubbers. For example, those polymers which are suitable in gum bases, include, without limitation, substances of vegetable origin such as chicle, jelutong, gutta percha and crown gum. Synthetic elastomers such as butadiene-styrene copolymers, isobutylene-isoprene copolymers, polyethylene, polyisobutylene and polyvinylacetate and mixtures thereof, are particularly useful.
The gum base composition may contain elastomer solvents to aid in softening the rubber component. Such elastomer solvents may comprise methyl, glycerol or pentaerythritol esters of rosins or modified rosins, such as hydrogenated, dimerized or polymerized rosins or mixtures thereof. Examples of elastomer solvents suitable for use herein include the pentaerythritol ester of partially hydrogenated wood rosin, pentaerythritol ester of wood rosin, glycerol ester of wood rosin, glycerol ester of partially dimerized rosin, glycerol ester of polymerized rosin, glycerol ester of tall oil rosin, glycerol ester of wood rosin and partially hydrogenated wood rosin and partially hydrogenated methyl ester of rosin, such as polymers of alpha-pinene or beta-pinene; terpene resins including polyterpene and mixtures thereof. The solvent may be employed in an amount ranging from about 10% to about 75% and preferably about 45% to about 70% by weight to the gum base.
A variety of traditional ingredients such as plasticizers or softeners such as lanolin, stearic acid, sodium stearate, potassium stearate, glyceryl triacetate, glycerine and the like for example, natural waxes, petroleum waxes, such as polyurethane waxes, paraffin waxes and microcrystalline waxes may also be incorporated into the gum base to obtain a variety of desirable textures and consistency properties. These individual additional materials are generally employed in amounts of up to about 30% by weight and preferably in amounts of from about 3% to about 20% by weight of the final gum base composition.
The chewing gum composition may additionally include the conventional additives of flavoring agents, coloring agents such as titanium dioxide, emulsifiers such as lecithin and glyceryl monostearate; and additional fillers such as hydroxide, alumina, aluminum silicates, calcium carbonate, and talc and combinations thereof. These fillers may also be used in the gum base in various amounts. Preferably the amount of fillers when used will vary from about 4% to about 30% by weight of the final chewing gum.
In the instance where auxiliary sweeteners are utilized in addition to those in the present delivery system, the present invention contemplates the inclusion of those sweeteners well known in the art, including both natural and artificial sweeteners. Thus, additional sweeteners may be chosen from the following non-limiting list, sugars such as sucrose, glucose (corn syrup), dextrose, invert sugar, fructose and mixtures thereof; saccharine and its various salts such as the sodium or calcium salt; cyclamic acid and its various salts such as the sodium salt; free aspartame, dihydrochalcone compounds, glycyrrhizin; Stevia rebaudiana (Stevioside); and sugar alcohols such as sorbitol, sorbitol syrup, mannitol, xylitol, and the like. Also contemplated as an additional sweetener is the nonfermentable sugar substitute (hydrogenated starch hydrolysate) which is described in U.S. Pat. No. Re. 26,959. Also contemplated is the synthetic sweetener 3,6-dihydro-6-methyl-1-1,2, 3-oxathiazin-4-one-2,2-dioxide, particularly the potassium (Acesulfame-K), sodium and calcium salts thereof as described in German Patent No. 2,001,017.7.
Suitable flavorings include both natural and artificial flavors, and mints such as peppermint, menthol, artificial vanilla, cinnamon, various fruit flavors, both individual and mixed, and the like are contemplated. Preferably the cinnamon is used and the flavorings are generally utilized in amounts that will vary depending upon the individual flavor, and may, for example, range in amounts of about 0.5% to about 3% by weight of the final chewing gum composition weight.
The colorants useful in the chewing gums of the present invention include the pigments such as titanium dioxide and may be incorporated in amounts of up to about 1% by weight, preferably up to about 6% by weight. Also, the colorants may include other dyes suitable for food, drug and cosmetic applications, and known as F.D. & C. dyes and the like. The materials acceptable for the foregoing spectrum of use are preferably water-soluble. Illustrative examples include indigo dye, known as F.D. & C. Blue No. 2, which is the disodium salt of 5.5'-indigotindisulfonic acid. Similarly, the dye known as F.D. & C. Green No. 1, comprises a triphenylmethane dye and is the monosodium salt of 4-[4-N-ethyl-p-sulfobenzylamino)diphenylnethylene]-[1-(N-ethyl-N-p-sulfoniumbenzyl)-2-5-cyclohexadienimine ]. A full recitation of all F.D. & C. and D. & C. and their corresponding chemical structures may be found in the KirkOthmer Encyclopedia of Chemical Technology, in Volume 5, at Pages 857-884, which text is accordingly incorporated herein by reference.
The chewing gum of the invention may be in any form known in the art, such as stick gum, slab gum, chunk gum, shredded gum, hard coated gum, tabletted gum, as well as center-filled gum.
The process of preparing the inventive chewing gum compositions is as follows. The gum base is melted (about 85° to about 90°), cooled to 78° C. and placed in a pre-warmed (60° C.) standard mixing kettle equipped with sigma blades. The emulsifier is then added and mixed in. Next, a portion of the sorbitol and the glycerin is added and mixed in for an additional 3 to 6 minutes. The mixing kettle is cooled and mannitol and the remainder of the sorbitol and glycerin are then added and mixing is continued. At this time, the unflavored chewing gum temperature is about 39° C.-42° C. Flavor oil is then added and incorporated into the base and the mixing is continued. Finally, the encapsulated dipeptide sweetener material is added and mixed for an additional 1 to 10 minutes. The encapsulated dipeptide is added as the last ingredient. The final gum temperature is about 39° C. to about 43° C. The chewing gum composition is then discharged from the kettle, rolled, scored and formed into chewing gum pieces.
The following examples are provided in an effort to set forth the various aspects of the present invention and to provide further appreciation for its advancement in the art. It is to be remembered that they are for illustrative purposes only and that minor alterations can be made in the types and amounts of materials used or processing parameters applied. They should therefore be regarded as illustrations only and not restrict the spirit and scope of the invention as recited in the claims that follow. Example 1
Several core formulations (A-E) using aspartame as the dipeptide sweetener were used to make the encapsulated compositions of the present invention. Table 1 represents the amounts of each component expressed as a percent by weight of the entire core sample. The ingredients were mixed under anhydrous conditions as a dry powder without the aid of water or other solvent in a twin shell dry blender (Model LB-832, Patterson Kelly Co., East Stroudsburg, PA.) The ingredients were mixed for ten (10) minutes and compressed into tablets of 0.875-1.0 inches in diameter with a hardness of 200 newton as shown by a Key HT 300 hardness tester. The tablets were then milled into granules of from about 30-45 U.S. standard mesh size (350-590 microns) and collected.
TABLE 1______________________________________ EXAMPLESINGREDIENTS #A #B #C #D #E______________________________________ASPARTAME 30.0% 30.0% 30.0% 30.0% 30.0%MICRO 68.3% -- 20.0% 23.3% --CRYSTALLINECELLULOSE -- -- -- -- 30.0%PH-105MAGNESIUM 0.7% 0.7% 1.0% 0.7% 1.0%STEARATEDICALCIUM -- 68.3% 47.0% 22.0% 37.0%PHOSPHATEMANNITOL -- -- -- 22.0% --COLLOIDAL 1.0% 1.0% 2.0% 2.0% 2.0%SILICONDIOXIDE 100% 100% 100% 100% 100%______________________________________
The compressed sweetener core granules were then coated with a mixture of partially hydrogenated soybean oil and glycerol monostearate using a Verse Glatt Fluid Bed. Agglomerator/Dryer Model CPCG-1 in which the core materials were suspended in a stream of air and spray coated. Examples F-J as shown in Table II represent the formulations for core examples A-E respectfully, based on a weight percentage of the entire fat encapsulated core.
TABLE II______________________________________ EXAMPLESINGREDIENTS #F #G #H #I #J______________________________________ASPARTAME 20.0% 15.0% 15.0% 15.0% 15.0%MICRO- 45.5% -- 10.0% 11.6% --CRYSTALLINEPH-102CELLULOSE -- -- -- -- 15.0%PH-105MAGNESIUM 0.5% 0.4% 0.4% 0.4% 1.0%STEARATEDICALCIUM -- 34.1% 24.1% 11.0% 18.5%PHOSPHATEMANNITOL -- -- -- 11.0% --COLLOIDAL 0.7% 0.5% 0.5% 1.0% 1.0%SILICONDIOXIDEPARTIALLY 31.6% 47.5% 47.5% 47.5% 47.5%HYDROGENATEDSOYBEAN OILGLYCEROL 1.7% 2.5% 2.5% 2.5% 2.5%MONOSTEARATE 100% 100% 100% 100% 100%______________________________________
The encapsulated aspartame compositions F-J were incorporated into five (5) samples of cinnamon-flavored chewing gum using the standard gum base technology described infra. The chewing gums were then analyzed at two, four and eight week intervals to determine the amount of undegraded aspartame remaining in the gums. The amount remaining is a direct correlation with the amount degraded and therefore allows a comparative analysis of the sweetness stability provided by the encapsulated dipeptide sweeteners of the present invention with those of other encapsulation methodologies.
FIG. 3 graphically represents the rate of aspartame degradation with respect to each one of five core compositions A-E encapsulated as sweetener sample F-J in cinnamon gum at 30° C. over time. Clearly, the chewing gum composition J consisting of core formulation E gave the best stability over time while chewing gum containing APM not compressed according to the present invention yet coated with three times (3 X) more fat/wax or elastomer materials showed the least amount of stability. Core materials H and I showed a dramatic improvement in stability but core sample J was clearly the superior sample.
Shelf life stability is not just a function of coating but is increased through physical/chemical changes of the aspartame crystals brought about by compaction of the needle-like crystals at high pressure so as to inbed them within naturally stabilizing inert matrix materials. Without being bound to any sort of theory, the tightly compacted APM becomes selected thereby prohibiting moisture and other reactive chemicals from invading the spaces that otherwise exist between the dendritic crystals. This compaction prevents degradation by reducing the surface area upon which heat, moisture and other chemicals can react. The milled granules are easier to coat since a uniform layer is far easier to achieve with the compacted, denser crystals. To be effective as protective barriers, coatings must be able to wet and adhere to the crystalline surface which is not generally possible considering the needle-like tips and other spike-like shape variations of pure aspartame powder. The coatings, in addition to being protective barriers, must be flexible enough to conform to the surface irregularities without cracking due to mechanical stresses which occur when the sweetener is incorporated into one of the numerous food applications, chewing gum in particular. The compacted granule not only facilitates such coating but is self-stabilized to a degree as well. | A stabilized dipeptide sweetening composition useful in chewing gum applications provides longer shelf life stability and improved longer lasting sweetness. A dipeptide sweetner such as appartame is encapsulated through an anhydrous process that compresses the crystals with a mixture of inert binder ingredients so as to form a solid tablet or sheet which is then ground into fine granular particles. These particles may then be coated with a hydrophobic material such as a fat or wax and then incorporated into a variety of food applications such as chewing gum. The sweetener composition is thereby protected from adverse environmental conditions such as high temperature, moisture and pH. | 0 |
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to electronic media storage and retrieval, and in particular, to the storage and retrieval of large amounts of data contained within magnetic tape cartridges. More specifically, the invention relates to an improved method and apparatus for prioritizing requests for data storage and retrieval of magnetic tape cartridges.
2. Description of the Related Art
In recent years, one method of electronic data storage has been the use of four-by-five inch, 200 megabyte tape cartridges. In the past, the storage and retrieval of such cartridges was for the most part carried out by human operators. Such human intervention not only decreased the reliability of tape selection and replacement, but also prolonged the time between when a data request was made and when that data was retrieved by loading a specific cartridge into an available tape drive.
Recent improvements have resulted in systems utilizing tape cartridges that incorporate magazine type automatic loaders which reduce the time that jobs wait for cartridges to be mounted and subsequently read. An example of an automated cartridge system (ACS) is taught by U.S. Pat. Nos. 4,945,429, 4,928,245, 4,932,826 and 4,864,511, all assigned to the Storage Technology Corporation, which are incorporated by reference herein.
FIG. 1 illustrates one such automated cartridge system. The automated cartridge system is made up of at least one library controller 121 (sometimes referred to as a library management unit (LMU)) and a plurality of library storage modules (LSM) 111, 112.
Each library controller 121 provides the interface between a host computer 101, 102 and the LSMs 111, 112. The library controller 121 interprets cartridge motion requests from the host computer 101, 102, relaying instructions to the appropriate LSMs 111, 112.
FIGS. 2-4 illustrate the top view and side view of an LSM 111, 112. Each LSM 111, 112 contains a plurality of storage cells 202 to store magnetic tape cartridges and a robot arm assembly 230 for handling the magnetic tape cartridges. The robot arm assembly 230 comprises a plurality of mechanisms all operating in conjunction to provide a movable arm 321 for retrieving tape cartridges from and returning tape cartridges to their individual storage cells 202. The robot arm 321 includes one or more hand assemblies 240 which performs the actual tape retrieval from, or replacement to, the individual storage cells 202.
Tape cartridges retrieved from the individual storage cells 202 are typically loaded onto tape drives 141, 142, 143, 144 so that the data contained on the tape cartridge can be read by the host computer 101, 102. One or more tape drives 141, 142, 143, 144 are attached to each of the LSMs 111, 112. The robot arm 321 loads a tape cartridge into the tape drive 141, 142, 143, 144 with the same motion as the replacement of a tape cartridge into one of the individual storage cells 202.
As illustrated in FIG. 5, tape cartridges are entered into and ejected from LSMs 111, 112 through the use of cartridge access ports (CAP) 160.
Tape cartridges may be transferred under robotic control from one LSM 111 to another LSM 112 through devices called "pass-through-ports" (PTPs) 150. As illustrated in FIG. 6, a PTP 150 is comprised generally of a plurality of storage cells 151, 152, 153, 154, called "PTP slots" adapted for rotation by a mechanism 155, called a "PTP mechanism" for transference between LSMs 111, 112. Through use of these PTPs 150, load sharing is accomplished. Tapes may be transported through PTP slots 151, 152, 153, 154 from one LSM 111 where they might be stored to another LSM 112 where there might be unused tape drives 141, 142, 143, 144. Thus, PTPs 150 allow for a more efficient use of available tape drives 141, 142, 143, 144.
In these systems, the task of transferring a cartridge from one location to another is initiated by a cartridge motion request from the host computer 101, 102 to the library controller 121. When the library controller 121 receives the request, it determines the proper path from the cartridge source to the cartridge destination. This path possibly includes source and/or destination storage cells 202, source and/or destination tape drives 141, 142, 143, 144, source and/or destination CAPs 160, and PTP slots 151, 152, 153, 154 for inter-LSM moves. The library controller 121 "allocates" available resources to cartridge motion requests to accomplish cartridge transfers.
The task of actually transferring a cartridge from one location within an LSM 111, 112 to another consists of two operations, a get and a put. In the get operation, the robotic means 230 retrieves the cartridge from a receptacle at a first location. In the put operation, the robotic means 230 moves the cartridge to its destination and inserts it into a receptacle at a second location.
Tape cartridge transfers along a path consist of the following: (1) path allocation; (2) source get; (3) one or more intermediate puts; (4) one or more intermediate gets; (5) destination put; and (6) path deallocation.
Path allocation consists of allocating for the duration of a tape cartridge transfer all PTP slots 151, 152, 153, 154 necessary for inter-LSM moves through the path, the source and/or destination tape drive 141, 142, 143, 144 and the source and/or destination CAPs 160. If the source tape drive 141, 142, 143, 144 or the source and/or destination CAP 160 are unavailable, the cartridge motion request is rejected. If any of the necessary PTP slots 151, 152, 153, 154 or tape drives 141, 142, 143, 144 are unavailable, the cartridge motion request, as described later, waits on a queue until said slot 151, 152, 153, 154 becomes available.
A source get consists of allocating the arm 321 and hand 240 of the robot mechanism 230 within the source LSM 111, 112 to retrieve a tape cartridge from the source location, whether it be a storage cell 202, tape transport 141, 142, 143, 144 or CAP 160. After the tape cartridge has been retrieved, the arm 321 is deallocated and is free to service other requests. However, the hand 240 remains allocated to the present request.
Intermediate puts and gets are repeated for intermediate LSMs 111, 112 along the selected path. An intermediate put always follows either a source get or intermediate get operation and, therefore, will have a hand 240 already allocated to the request. The intermediate put delivers a cartridge to a PTP slot 151, 152, 153, 154 in an LSM 111, 112. The intermediate put consists of a two step process. First, the PTP mechanism 155 in the intermediate LSM 111, 112 is allocated to the request to receive a cartridge and, second, the arm mechanism 321 within the intermediate LSM 111, 112 is allocated to move the cartridge to and insert it into the PTP slot 151, 152, 153, 154 in that LSM 111, 112. The arm 321, hand 240 and PTP mechanism 155 are deallocated upon completion of the intermediate put.
The intermediate get retrieves a cartridge from a PTP slot 151, 152, 153, 154. The intermediate get consists of a three step process. First, a hand 240 in the intermediate LSM 111, 112 is allocated to the request to retrieve the cartridge from a PTP slot 151, 152, 153, 154. Second, the PTP mechanism 155 is allocated to position the PTP slot 151, 152, 153, 154 in the intermediate PTP 150 for transference of the cartridge. Finally, the arm mechanism 321 within the intermediate LSM 111, 112 is allocated to retrieve a cartridge from the PTP slot 151, 152, 153, 154. The arm 321 and PTP mechanism 155 are deallocated upon completion of the intermediate get. The hand 240 remains allocated to the request.
Destination puts are similar to intermediate puts in that they always follow either a source get or intermediate get operation and, therefore, will have a hand 240 already allocated to the request. The destination put consists of allocating an arm mechanism 321 within the destination LSM 111, 112 to move a cartridge to and insert it into the destination storage cell 202, tape drive 141, 142, 143, 144 or CAP 160. Upon completion of the destination put, the arm 321 and hand 240 allocated to the request are deallocated.
When the tape cartridge has reached its destination location, all PTP slots 151, 152, 153, 154 for inter-LSM moves through the path, the source and/or destination tape drives 141, 142, 143, 144 and the source and/or destination CAPs 160 are deallocated.
As described above, the library controller 121 allocates available resources to cartridge motion requests to accomplish cartridge transfers. However, because the library controller 121 may be asked to execute a plurality of cartridge motion requests at any one time, cartridge motion requests compete for available resources. The library controller 121 manages the competition for available resources by allocating the available resources to the cartridge motion requests on a first-come first-served basis. Cartridge motion requests that request resources first are granted them first. A plurality of queues are implemented to handle the allocation of available resources: a PTP slot queue, a PTP mechanism queue, a drive queue, a hand queue and an arm queue.
When a new cartridge request is received, it is examined to determine if its destination is a tape drive 141, 142, 143, 144 and, if so, if the destination tape drive 141, 142, 143, 144 is available. If the destination tape drive 141, 142, 143, 144 is available, the drive is allocated to the request and processing of the request continues. If the drive 141, 142, 143, 144 is not available, the request is placed in a drive queue. The library controller 121 determines if a tape drive 141, 142, 143, 144 has become available. If a drive 141, 142, 143, 144 becomes available, the library controller 121 scans the drive queue from the oldest entry to the newest entry to determine if any requests in the drive queue need the available tape drive 141, 142, 143, 144. The available tape drive 141, 142, 143, 144 is allocated to the first request in the queue waiting on that tape drive 141, 142, 143, 144.
If the source location and the destination location are in different LSMs 111, 112, the library controller 121 determines if the necessary PTP slots 151, 152, 153, 154 are available. If the necessary PTP slots 151, 152, 153, 154 are available, the PTP slots 151, 152, 153, 154 are allocated to the request and the path for that particular request is granted, i.e., path allocation. Otherwise, the cartridge motion request is queued on the end of the PTP slot queue, implemented in the library controller's 121 computer memory.
Each time a PTP slot 151, 152, 153, 154 becomes available, the PTP slot queue is scanned from the oldest entry to the newest entry to determine which cartridge motion requests in the queue are waiting on that PTP slot 151, 152, 153, 154. The first request found for which all necessary PTP slots 151, 152, 153, 154 are available is granted the path and the necessary PTP slots 151, 152, 153, 154 are allocated to it, i.e., path allocation.
Once a path has been allocated to the cartridge motion request, the tape cartridge is transferred along the granted path through a succession of gets (i.e., a source get and a series of intermediate gets) and puts (i.e., a series of intermediate puts and a destination put).
The allocation of available resources to complete a get is as follows. The cartridge motion request is entered into the hand queue, organized from the oldest entry to the newest, to wait until a hand 240 becomes available. When a hand 240 becomes available, the hand queue is scanned from the oldest entry to the newest entry to determine which request in the queue is waiting on the available hand 240. The available hand 240 is allocated to the first request in the hand queue needing that hand 240. If a transfer between LSMs 111, 112 is involved, the cartridge motion request is entered into the PTP mechanism queue, organized from the oldest entry to the newest, to wait until a PTP mechanism 155 becomes available. When a PTP mechanism 155 becomes available, the PTP mechanism queue is scanned from the oldest entry to the newest entry to determine which request in the queue is waiting on the available PTP mechanism 155. The available PTP mechanism 155 is allocated to the first request in the PTP mechanism queue needing that hand 240. The request is then entered into an arm queue to wait until an arm 321 becomes available. When an arm 321 becomes available the arm queue is scanned from the oldest entry to the newest entry to determine which request in the arm queue is waiting on the available arm 321. The available arm 321 is assigned to the first request in the arm queue needing that arm 321. The request is then satisfied by moving the robotic arm 321 so as to move the hand 240 to the location of the receptacle containing the cartridge that is sought and then using the hand 240 to remove the cartridge from that receptacle.
At this point the get is complete. The arm 321 and PTP mechanism 155 are released for reallocation to the next request in the arm queue needing that arm 321 and the next request in the PTP mechanism queue needing that PTP mechanism 155. The hand 240 retains the cartridge it has retrieved and accordingly cannot be released. The request is then returned to the back of the arm queue to wait for an available arm 321 so it that it can complete its transfer through a put operation.
The put operation is essentially the same as that described in the previous paragraph. Upon completion of the get, the request is returned to the arm queue and, if necessary, the PTP mechanism queue, each queue being organized from the oldest entry to the newest, to wait until an arm 321 and PTP mechanism 155 necessary for the put become available. When a PTP mechanism 155 becomes available, the PTP mechanism queue is scanned from the oldest entry to the newest entry to determine which request in the queue is waiting on the available PTP mechanism 155. The available PTP mechanism 155 is allocated to the first request in the PTP mechanism queue needing that hand 240. When an arm 321 becomes available, the arm queue is scanned from the oldest entry to the newest entry to determine which request in the queue is waiting on the available arm 321. The available arm 321 is allocated to the first request in the arm queue needing that arm 321. When an arm 321 is allocated to the request, the arm 321 is moved so as to move the hand 240 and the cartridge contained therein to the receptacle at the destination location. The hand 240 then inserts the cartridge into the receptacle whereupon the put is complete. The PTP mechanism 155, arm mechanism 321 and hand 240 are then released for reallocation to the next request in the PTP mechanism queue, arm queue and hand queue, respectively.
In the operations described above, there exists one resource queue for each resource, i.e., PTP mechanism 155, drive 141, 142, 143, 144, hand 240 and arm 321, for the entire automatic cartridge system. Each time a resource becomes available, the appropriate queue is scanned from the oldest entry to the newest entry to determine which request in the queue is waiting on the available resource.
In an alternative implementation, there exists one resource queue for each resource for each LSM 111, 112 in the automated cartridge system. Each time a resource become available in an LSM 111, 112, it is allocated to the first element on the queue (in a first-come, first serve implementation, the first entry on the queue will always be the oldest request). This implementation eliminates the need to scan the queue to determine which request in the queue is waiting on the available resource.
As mentioned above, in these automated cartridge systems, cartridge requests are performed only on a first-come first-served basis. That is, all cartridge requests are forced to compete for the available resources on an equal footing, and those that request the resources first are granted them first. While this method of performing transfers operates as described, experience has shown that its performance could be improved. The operators of these systems are unable to modify the order in which the library controller 121 performs these requests. This prevents operators from prioritizing the requests, that is, compelling the ACS to perform an important cartridge request first, although they may have been sent to the system subsequent to less important cartridge transfer requests.
Therefore, there is a need for a method and apparatus for prioritizing requests for tape retrieval within an automated cartridge system (ACS).
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an ACS which prioritizes requests for tape retrieval. The cartridge requests may be assigned a priority relating to the urgency of the request. The ACS will recognize these requests and organize them so that higher priority requests will be executed ahead of other lower priority requests.
It is another object of the present invention to carry out the prioritization in such a manner that even low priority requests will eventually be executed. To avoid the problem of lower priority jobs being held off indefinitely by a stream of incoming jobs with higher priorities, each time a mechanism is granted to a request, all lower priority requests waiting for that mechanism have their priority incremented by a predetermined amount.
It is another object of the present invention to provide the capability to execute certain requests only when no other requests are pending in the system. In accordance with this object of the invention, a special priority is assigned to these requests that inhibit their execution until no other requests are pending in the system.
It is another object of the present invention to provide the capability to execute certain requests before all current requests pending in the system. In accordance with this object of the invention, a super priority is assigned to these requests that is greater than any priority that may be assigned by the system.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the inventions will be more readily apparent from the following detailed description of the invention in which:
FIG. 1 illustrates the automated magnetic tape cartridge library system in block diagram form;
FIG. 2 illustrates a top view of a library module;
FIG. 3 illustrates a cut away view of a library module with its associated robot arm mechanism and tape cartridge storage cell array;
FIG. 4 illustrates a perspective view of the robot arm mechanism;
FIG. 5 illustrates in plan view the access doors and cartridge access port shown in FIG. 2;
FIG. 6 illustrates in detail the pass through port shown in FIG. 2;
FIGS. 7a-1, 7a-2, 7b-1 and 7b-2 are flowcharts of an embodiment of the invention which provides for task optimization;
FIGS. 8a-1, 8a-2, 8b-1 and 8b-2 are flowcharts of an alternative embodiment of the invention illustrating incrementation of priorities of request in a queue; and
FIGS. 9a-1, 9a-2, 9b-1 and 9b-2 are flowcharts of an alternative embodiment of the invention illustrating incrementation of priorities of requests not selected for execution.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 7a-1, 7a-2, 7b-1 and 7b-2 are an embodiment of the invention for task prioritization in an ACS which may have a plurality of LSMs 111, 112 inter-connected by PTP mechanisms 155. In accordance with the invention, task prioritization is achieved by assigning a priority to each cartridge request. The priority of each request illustratively is a value from 0 to 99 with 99 being highest.
When a new cartridge request is received (step 10), it is examined to determine if its destination is a tape drive 141, 142, 143, 144 (step 11) and, if so, if the destination tape drive 141, 142, 143, 144 is available. If the destination drive 141, 142, 143, 144 is available, the drive 141, 142, 143, 144 is allocated to the request and processing of the request continues at step 15. If the drive 141, 142, 143, 144 is not available, the request is placed in a drive queue behind all requests of equal or greater priority and in front of all others (step 33). At step 47, the library controller 121 determines if a drive 141, 142, 143, 144 has become available. If a tape drive 141, 142, 143, 144 is now available, the library controller 121 determines if any requests in the drive queue need the available tape drive 141, 142, 143, 144 by scanning the drive queue from the highest priority request to the lowest priority request (step 67). The available tape drive 141, 142, 143, 144 is allocated to the first request in the queue waiting on that tape drive 141, 142, 143, 144 (step 87).
In alternative embodiment shown in FIGS. 8a-1, 8a-2, 8b-1 and 8b-2, to avoid the problem of lower priority requests being held off indefinitely, after the request is placed in the drive queue behind all requests of equal or greater priority and in front of all others (step 33), the library controller 121 increments the priority of all requests in the drive queue of priority lower than the newly entered request (step 107).
A further alternative embodiment is shown in FIGS. 9a-1, 9a-2, 9b-1 and 9b-2. Rather than increasing the priority after a new request has been entered in the drive queue of all requests in the hand queue with a priority lower than the newly entered request, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments after allocation of a drive 141, 142, 143, 144 the priority of all lower priority requests in the drive queue waiting for the allocated drive 141, 142, 143, 144 (step 127).
Referring back to FIGS. 7a-1, 7a-2, 7b-1 and 7b-2, after the destination drive 141, 142, 143, 144 has been allocated to the request, the request is examined to determine if a PTP slot 151, 152, 153, 154 is needed (step 15). All requests which need a PTP slot 151, 152, 153, 154 are placed in a PTP slot queue behind all requests of equal or greater priority and in front of lower priority requests (step 35). If PTP slots 151, 152, 153, 154 are available, the library controller 121 determines if any requests in the PTP slot queue need the available PTP slot 151, 152, 153, 154 by scanning the PTP slot queue from the highest priority request to the lowest priority request (step 70). When a request in the PTP slot queue is found for which all necessary PTP slots 151, 152, 153, 154 are available, the request is granted the path, i.e., the necessary PTP slots 151, 152, 153, 154 are allocated to it (step 90).
Referring again to FIGS. 8a-1, 8a-2, 8b-1 and 8b-2, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments the priority of all requests in the PTP slot queue of priority lower than the newly entered request (step 110). At step 50 the library controller 121 determines if any PTP slots 151, 152, 153, 154 are available.
In the further alternative embodiment shown in FIGS. 9a-1, 8a-2, 9b-1 and 9b-2, rather than increasing after a new request has been entered in the PTP slot queue the priority of all requests in the PTP slot queue with a priority lower than the newly entered request, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments after allocation of the PTP slots 151, 152, 153, 154 the priority of all lower priority requests in the PTP slot queue waiting for the allocated PTP slots 151, 152, 153, 154 (step 130).
Referring back to FIGS. 7a-1, 7a-2, 7b-1 and 7b-2, once the request is granted a path, the library controller 121 examines the request to determine if a hand 240 is needed (step 20). If a hand 240 is needed, the request is placed in a hand queue behind all requests of equal or greater priority and in front of all others (step 40). At step 55, the library controller 121 determines if a hand 240 has become available. If a hand 240 is now available, the library controller 121 determines if any requests in the hand queue need the available hand 240 by scanning the hand queue from the highest priority request to the lowest priority request (step 75). The available hand 240 is allocated to the first request in the queue waiting on that hand 240 (step 95).
As illustrated in the alternative embodiment shown in FIGS. 8a-1, 8a-2, 8b-1 and 8b-2, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments the priority of all requests in the hand queue of priority lower than the newly entered request (step 115).
Illustrated in the further alternative embodiment shown FIGS. 9a-1, 9a-2, 9b-1 and 9b-2, rather than increasing after a new request has been entered in the hand queue the priority of all requests in the hand queue with a priority lower than the newly entered request, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments after allocation of a hand 240 the priority of all lower priority requests in the hand queue waiting for the allocated hand 240 (step 135).
Referring back to FIGS. 7a and 7b, all requests which need a PTP mechanism 155 are placed in a PTP mechanism queue behind all requests of equal or greater priority and in front of all others (step 45). At step 60 the library controller 121 determines if an PTP mechanism 155 is available. If a PTP mechanism 155 is available, the library controller 121 determines if any requests in the PTP mechanism queue need the available PTP mechanism 155 by scanning the PTP mechanism queue from the highest priority request to the lowest priority request (step 80). The available PTP mechanism 155 is allocated to the first request in the queue waiting on that PTP mechanism 155 (step 100).
As illustrated in FIGS. 8a-1, 8a-2, 8b-1 and 8b-2, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments the priority of all requests in the PTP mechanism queue of priority lower than the newly entered request (step 120).
In the further alternative embodiment shown in FIGS. 9a-1, 9a-2, 9b-1 and 9b-2, rather than increasing after a new request has been entered in the PTP mechanism queue the priority of all requests in the PTP mechanism queue with a priority lower than the newly entered request, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments after allocation of a PTP mechanism 155 the priority of all lower priority requests in the PTP mechanism queue waiting for the allocated PTP mechanism 155 (step 140).
Referring again to FIGS. 7a-1, 7a-2, 7b-1 and 7b-2, all requests which need an arm 321 are placed in a wait arm queue behind all requests of equal or greater priority and in front of all others (step 30). At step 65 the library controller 121 determines if an arm 321 is available. If an arm 321 is available, the library controller 121 determines if any requests in the arm queue need the available arm 321 by scanning the arm queue from the highest priority request to the lowest priority request (step 85). The available arm 321 is allocated to the first request in the queue waiting on that arm 321 (step 105).
As illustrated in FIGS. 8a-1, 8a-2, 8b-1 and 8b-2, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments the priority of all requests in the arm queue of priority lower than the newly entered request (step 125).
In further alternative embodiment shown in FIGS. 9a-1, 9a-2, 9b-1 and 9b-2, rather than increasing after a new request has been entered in the arm queue the priority of all requests in the arm queue with a priority lower than the newly entered request, to avoid the problem of lower priority requests being held off indefinitely, the library controller 121 increments after allocation of an arm 321 the priority of all lower priority requests in the arm queue waiting for the allocated arm 321 (step 145).
In the operations described above, there exists one resource queue for each resource, i.e., PTP mechanism 155, drive 141, 142, 143, 144, hand 240 and arm 321, for the entire automatic cartridge system. Each time a resource becomes available, the appropriate queue is scanned from the oldest entry to the newest entry to determine which request in the queue is waiting on the available resource.
In an alternative implementation, there exists one resource queue for each resource for each LSM 111, 112 in the automated cartridge system. Each time a resource become available in an LSM 111, 112, it is allocated to the first element on the queue (with task prioritization, the first entry on the queue will have the highest priority). This implementation eliminates the need to scan the queue to determine which request in the queue is waiting on the available resource.
Another embodiment of the present invention provides the capability to execute certain requests only when no other requests are pending in the system. A special priority is assigned to these requests that inhibit their execution until no other requests are pending in the system. In accordance with this embodiment, the library controller 121 assigns a priority of 0 to those requests that are to be executed only when no other requests are pending in the system ("priority 0 requests"). The library controller 121 never increments the priority of priority 0 requests. As a result, these priority 0 request will only be executed by the system when no other requests are competing for available resources.
Another embodiment of the present invention provides the capability to execute certain requests before all current requests pending in the system. A super priority is assigned to these requests that is greater than any priority that may be assigned by the system. In accordance with this embodiment, the library controller 121 assigns a priority of 99 to those requests that are to be executed before all current requests pending in the system ("priority 99 requests"). The library controller 121 never increments the priority of a request pending in the system to a priority greater than 98. As a result, priority 99 requests are allocated available resources before all non-priority 99 requests pending in the system.
Various methods of prioritizing the cartridge requests may be used in accordance with the invention. In one example, the library controller 121 may have numerous hosts. Each host can be set up to send requests at a priority that relates to the response time required for that particular host. For instance, a host connected to customer accounts may have a higher priority attached to its requests than a host which handles cartridge requests for engineers.
In another example, priorities could be assigned on a user by user basis. For instance, the system administrator would have a higher priority attached to his requests than say a financial analyst.
In a final example, prioritization could be assigned to cartridge requests based on the type of robot motion that will be required. As an example, cartridge entries into the system would have a higher priority than cartridge removals from the system. It should also be noted that a combination of the preceding examples could also be implemented.
A computer program listing one embodiment of an implementation of task prioritization for a tape storage system is attached as an appendix hereto.
Various embodiments of the invention have been described. The descriptions are intended to be illustrative, not limitative. Thus, it will be apparent to those skilled in the art that certain modifications may be made to the invention as described without departing from the scope of the claims set out below. ##SPC1## | An automated memory cartridge system prioritizes requests for tape retrieval. The requests to transfer cartridges may be assigned a priority relating to the importance of the request. The system will recognize these requests and organize them so that higher priority requests will be executed ahead of other lower priority requests. This prioritization will be accomplished in such a manner which allows even very low priority requests to eventually be carried out. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to electric- or fluid-powered torque-applying tools, and more specifically, to control methods for such power tools.
2. Description of Related Art
Computer-controlled fluid- or electric-power tools are typically used in production environments to secure threaded fasteners (e.g., nuts and bolts) into joints. Such power tools typically include a handheld unit coupled to a controller. The handheld unit, or tool, usually has a high-speed, high-torque motor coupled to a universal adapter head. Various interchangeable bits are connected to the head in order to drive threaded fasteners, e.g., bits appropriate for hex-head bolts and hexagonal nuts. The motor of each handheld unit is usually rated to apply no more than a maximum amount of torque, and is also usually rated to run at no more than a maximum speed.
The controller for each handheld unit controls the power supply for each handheld unit, and also monitors such parameters as the current tool speed and current applied torque. In a typical fastening job, fasteners are tightened to a predetermined, specified torque. As the handheld units operate at high speed, on the order of several hundred RPM, the controller is typically used to start and stop the motor of the handheld unit automatically so that the torque applied to the fastener and joint does not exceed the specified torque or the torque rating of the tool's motor.
The high speed at which the tool's motor operates means that a single fastening job, for example tightening a single bolt, may only require a few milliseconds. Therefore, even though the tools are computer-controlled, there is a substantial likelihood that the tool will “overshoot” the desired torque, thus increasing the stress on the joint and potentially damaging the tool.
Joints are usually classified by their torque/turn rates. The torque/turn rate is defined as the ratio of change in torque per unit of rotation of the fastener. A fastening application is considered “soft” when the torque/turn rate is low, and is considered “hard” when the torque/turn rate is high. Joints may also be classified as “medium” or may be completely irregular in their properties.
In evaluating the characteristics of a fastening job, the tool's torque/time rate is also important. The torque/time rate is dependent upon the rotational speed of the tool and the torque/turn rate of the fastener itself, therefore, the torque/time rate is strongly influenced by the torque/turn rate. In general, a high torque/time rate is indicative of a “hard” joint, while a relatively low torque/time rate is indicative of a “soft” joint. A high torque/time rate is one of the factors which contributes to the problem of torque “overshoot.”
To remedy the problem of torque overshoot, the user may simply choose to run the tool at a lower rotational speed. Unfortunately, that simple solution is not practical in production environments because a slower-running tool takes more time to finish a tightening process, thereby decreasing worker productivity and potentially causing the tool motor to overheat.
Because of the variability in joint properties, it becomes difficult to design a computer algorithm to properly control a torque-applying tool. Previous attempts have resulted in algorithms with somewhat limited utility.
Commonly-assigned U.S. Pat. No. 5,315,501 to Whitehouse discloses an algorithm for controlling power tools. The algorithm determines an internal torque target based upon the torque/turn or torque/time rate of the joint and dynamic characteristics of the tool, where the rate is calculated based on the controller-observed properties of several different joints. For optimum results, this algorithm must be used on a joint in which the amount of torque monotonically increases. This type of joint is not often encountered in practice, thus limiting the applicability of the algorithm. In cases where the algorithm can be applied, the controller is required to analyze up to 75% of the torque/turn characteristic of the joint before enabling the control algorithm. Given that “hard” joints can be tightened in less than 10 ms, the controller usually does not have sufficient time to shut the tool down when the internal torque target is reached, resulting in torque overshoot. The method also preferably requires the use of an angular measuring device, which increases the cost of the system. Moreover, the angular measurements required for the method may not be accurate, because in a typical tool, the angular measurement changes if the user changes the position of the tool while tightening a joint.
Commonly-assigned U.S. Pat. No. 5,637,968 to Kainec et al. discloses an alternate method of power tool control in which the controller measures the torque/turn rate of the joint between 25% and 50% of the programmed target torque to classify the joint as either “soft,” “medium,” or “hard.” The controller then issues a command to execute an immediate downshift in speed based on the joint classification. The controller continues the tightening process at the reduced speed until the programmed target torque is reached.
The design disclosed in the Kainec patent can be improved in several ways. First, on a “hard” joint, if the motor speed is reduced at 50% of the target torque and the tool is running at, for example, 1500 RPM, the tool has only about 1.5 ms to slow down before the target torque is reached, whereas the typical response time for a control system can be much greater than that. The immediate downshift imposed by the Kainec method is undesirable because the immediate change in speed can induce damaging dynamic loads on the motor and gearing. Immediate downshifts also consume more power, because the controller attempts to dynamically brake the tool's motor. Moreover, the dynamic braking process itself causes the tool and controller to heat up unnecessarily.
The classification system imposed by the Kainec method also imposes some limitations. By categorizing all joints into one of only three categories and requiring a specific, fixed downshift in tool speed for each category, the method may prevent the controller from tightening each joint optimally. For example, a joint with a characteristic between “hard” and “soft” would be classified as a “medium” joint, and the controller would reduce speed at 50% of the target torque, which would actually increase the amount of time it takes to fasten the joint. For most joints, the Kainec method actually increases the amount of time it takes to fasten the joint. Additionally, the method does not account for the tool's speed, so even when a joint is correctly classified, torque overshoot may still be a problem because a faster tool on a particular joint may require a greater reduction in tool speed in order to avoid overshoot.
Immediate downshifts in tool speed are also generally undesirable because of the manner in which torque-applying tools are tested. Typically, torque-applying tools are tested by using brakes to simulate the effects of tightening a threaded fastener. However, brakes have very high polar moments of inertia when compared to typical joint assemblies, which can affect the dynamic response time of the control system and an immediate downshift may cause instability, erratic torque readings, and thus, inaccurate test results.
Other power tool control algorithms that are commonly used include learning-based algorithms. A learning-based algorithm requires that the tool and controller be used on several “test” joints of a particular type so that the controller can adapt the tool's speed and performance to the characteristics of that particular joint. The controller runs the tool at various speeds until an optimum speed profile is determined for the particular type of joint. Unfortunately, once the learning algorithm is employed, the tool and controller may only be used optimally on the particular type of joint for which the controller has “trained.”
One example of this type of learning-based algorithm is disclosed U.S. Pat. No. 5,215,270 to Udocon et al. The disclosed method applies continuous feedback control over the tool's speed to maintain an “optimum” speed. The optimum speed is calculated by using an equation which includes empirical constants that must be determined for each joint. The method may either increase or decrease the tool's speed to meet the calculated optimum speed.
Another example of a learning-based algorithm is disclosed in U.S. Pat. No. 5,650,574 to Sato et al. In this method, a family of tool speed profiles are precalculated and are stored in the tool controller. Over the course of several learning cycles, the controller implements each one of the family of tool speed profiles in succession, changing speed profile until the chosen tool speed profile causes no torque overshoot.
Aside from learning-based methods, some power tool control methods have employed continuous feedback control of tool speed based on the tool's measured, applied torque, but these methods generally do not prevent torque overshoot. For example, U.S. Pat. No. 5,519,614 to Hansson discloses a similar continuous feedback control method in which the tool is held to a calculated, optimum rate of torque application, but the control method is used only to control the reaction forces experienced by the user.
SUMMARY OF THE INVENTION
There exists a need for an adaptive control method for a torque-applying tool that correctly fastens a joint to a specified torque without overshoot, regardless of the torque rate or class of the joint, or that does not require the torque-applying tool to test or learn a particular type of joint.
An exemplary method of controlling a torque-applying tool to apply a selected torque by controlling a speed of the torque applying tool includes calculating a first torque at an end of a deceleration ramp that is a percentage of the selected torque, calculating a second torque at a start of the deceleration ramp that is a percentage of the selected torque, calculating a first speed at the end of the deceleration ramp that is a percentage of a selected speed, periodically determining a peak torque applied by the tool, determining if the peak torque is greater than the first torque, stopping the tool, if the peak torque is greater than or equal to the first torque and the selected torque, determining if the peak torque is greater than or equal to the second torque, if the peak torque is not greater than the first torque, and calculating parameters descriptive of the deceleration ramp and controlling the speed in accordance with the parameters, if the peak torque is greater than or equal to the second torque.
Another exemplary method of controlling a torque applying tool to apply a selected torque by controlling a speed of the torque applying tool includes determining a final torque value, determining a final speed value, decreasing speed levels until the torque applying tool reaches the final torque value, periodically measuring the torque level until the final torque value is measured, and stopping the torque applying tool when the selected torque value is reached.
An exemplary torque-applying tool according to the invention includes a motor, a drive head that is driven by the motor, a sensor package including a torque sensor and a speed sensor, and a controller that calculates a first torque at an end of a deceleration ramp that is a percentage of a selected torque, calculates a second torque at a start of the deceleration ramp that is a percentage of the selected torque, calculates a first speed at the end of the deceleration ramp that is a percentage of a selected speed, periodically determines a peak torque applied by the tool, determines if the peak torque is greater than the first torque, stops the tool, if the peak torque is greater than or equal to the first torque and the selected torque, determines if the peak torque is greater than or equal to the second torque, if the peak torque is not greater than the first torque, and calculates parameters descriptive of the deceleration ramp and controls the speed in accordance with the parameters, if the peak torque is greater than or equal to the second torque.
An exemplary controller for a torque-applying tool including a motor, a drive head that is driven by the motor, a sensor package including a torque sensor and a speed sensor, calculates a first torque at an end of a deceleration ramp that is a percentage of a selected torque, calculates a second torque at a start of the deceleration ramp that is a percentage of the selected torque, calculates a first speed at the end of the deceleration ramp that is a percentage of a selected speed, periodically determines a peak torque applied by the tool determines if the peak torque is greater than the first torque, stops the tool, if the peak torque is greater than or equal to the first torque and the selected torque, determines if the peak torque is greater than or equal to the second torque, if the peak torque is not greater than the first torque, and calculates parameters descriptive of the deceleration ramp and controls the speed in accordance with the parameters, if the peak torque is greater than or equal to the second torque.
BRIEF DESCRIPTION OF THE DRAWINGS
Various exemplary embodiments will be described with reference to the following drawings, in which like reference characters represent like features, wherein:
FIG. 1 illustrates a torque-applying tool and controller according to the present invention;
FIG. 2 is a flow diagram illustrating a method of controlling a tool according to one exemplary embodiment of the present invention;
FIGS. 3A and 3B are flow diagrams illustrating another method of controlling a tool according to another exemplary embodiment of the present invention;
FIGS. 4A and 4B are plots illustrating a first example of a use of the present invention;
FIGS. 5A and 5B are plots illustrating a second example of a use of the present invention;
FIGS. 6A and 6B are plots illustrating a third example of a use of the present invention;
FIGS. 7A and 7B are plots illustrating a fourth example of a use of the present invention: and
FIG. 8 is a graph explaining the relationship between the percent of rated speed at the end of ramping versus the target torque percent of rated torque.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 illustrates an exemplary torque-applying tool 100 and controller 102 according to the present invention. The tool 100 includes a high speed electric motor 104 coupled to a drive head 106 . The drive head 106 includes a rotatably driven spindle 107 that accepts interchangeable threaded fastener engaging members, such as sockets, allowing the tool 100 to drive a variety of threaded fasteners. The tool 100 also includes a tool electronics board (TEB) 108 that interfaces electronically with the controller 102 , and a sensor package 110 that communicates with the controller 102 . The torque and speed rating of the motor 104 of the torque-applying tool 100 are stored in the tool electronics board 108 . The sensor package 110 includes a torque sensor and a speed sensor that measure the torque applied by the tool 100 and the speed at which the tool 100 is operating, respectively. A tool without a tool electronics board 108 may be used in the present invention if the tool parameters that are typically stored in the tool electronics board 108 are entered into the controller 102 by a user, or through other means.
The sensor package 110 may be integral to the motor 104 . For example, the motor 104 may be a brushless servomotor with an internal angular encoder that determines the position of the armature relative to the stator windings. Such an angular encoder may also be used to determine if an error condition exists during tightening, as will be described below.
Although the torque-applying tool has thus far been described with respect to a tool including an electric motor, it should be understood that the present invention may be applied to a number of different types of computer-controlled torque-applying tools, of which tool 100 is only one example. In particular, the present invention may also be applied to computer-controlled fluid powered tools, such as pneumatic and hydraulic tools. It should also be understood that the tool 100 need not be a handheld tool. Rather, a tool 100 could be mounted in a permanent, articulating fixture and controlled remotely or robotically. Such a mounted tool would be especially applicable to an industrial assembly line environment, in which it might be programmed to activate when a part reaches a predetermined location in the assembly line.
The controller 102 provides a user-programmable interface for the tool 100 , communicating with the tool electronics board 108 through connector 112 . The controller 102 has a display 114 , for example an LED display, and an input panel 116 . The input panel 116 allows a user to input process parameters for a specific fastening job into the controller 102 , such as a programmed target torque and a programmed free speed. The controller 102 may also be provided with a network interface 118 . The network interface 118 connects the controller 102 to an external computer, such as a personal computer, so that the programmed target torque and the programmed free speed can be input remotely. The network interface 118 also allows a number of controllers 102 and tools 100 to be programmed and monitored remotely by a single user at a single computer. In the following discussion, it is understood that a user may program the controller 102 either from the input panel 116 or from an external computer connected to the network interface 118 with the same results.
It should also be understood that although the controller 102 in this exemplary embodiment is implemented as a specialized computer system with its own microprocessor, display 114 , and input panel 116 , the controller 102 may be a general purpose computer or any other computing system capable of implementing the controls 200 , 300 that are discussed below. It should also be appreciated that the controller may be integrated into the tool 100 , rather than provided separately.
The controller 102 monitors the torque and the speed of the tool 100 during fastening operations and adjusts the speed of the tool 100 appropriately to prevent torque overshoot. In a first exemplary embodiment of the present invention, the controller 102 determines the peak torque applied by the tool 100 at 1 ms intervals and commands changes in the speed of the tool 100 in accordance with the determined torque. The controller 102 actively adjusts the speed of the tool 100 while the tool is in operation and does so without the use of an angular encoder. This type of continuous, active control over the speed of the motor 100 minimizes torque overshoot while maintaining a fast time-to-torque.
FIG. 2 is a flow diagram illustrating a first exemplary embodiment of a control 200 implemented by the controller 102 to control the speed of the tool 100 during operation. The control 200 may be embodied in a computer program stored in tie controller 102 , and uses certain fastening process parameters and values, the abbreviations and meanings of which are listed in Table 1.
TABLE 1
Abbreviation
Explanation
SR
Speed Rating of Tool
TR
Torque Rating of Tool
TP
Programmed Target Torque
TP %
Target Torque Percent of Rated Torque
SP
Programmed Free Speed
TPK
Peak Measured Torque
TSR
Torque at Start of Ramping
TSR %
Percent of Programmed Torque at Start of
Ramping
SSR
Speed at Start of Ramping
TER
Torque at End of Ramping
TER %
Percent of Programmed Torque at End of
Ramping
SER
Speed at End of Ramping
SER %
Percent of Rated Speed at End of Ramping
SC
Speed Command
Control 200 begins in S 202 when the controller 102 and tool 100 are first turned on. Control then proceeds to S 204 where the controller 102 interrogates the tool electronics board 108 to determine the torque rating and the speed rating of the tool 100 . Control then proceeds to S 208 . In S 208 a programmed free speed SP and programmed target torque TP (the target final torque on the joint) are input either at the controller input panel 116 or at a computer connected to the network interface 118 .
The control 200 uses ramped speed profiles to control the speed of the motor 104 . In other words, once the controller 102 determines that the speed of the tool 100 should be decreased, it decreases the speed command SC in proportion to the increase in torque. The controller 102 implementing control 200 starts the speed “ramp down” at the preprogrammed percent of programmed torque at start of ramping TSR %. Control 200 stops the speed “ramp down” of the motor 104 by determining the peak measured torque TPK and comparing the peak measured torque TPK to parameters that are stored in or determined by the controller 102 . The parameters include the torque at the start of the ramping TSR and the torque at the end of ramping TER.
In general, the value chosen for the percent of programmed torque at the start of ramping TSR % should be chosen so as to be high enough to avoid premature enabling of control 200 before the joint is sufficiently snug, but should also be low enough to allow sufficient time to enable control 200 before the joint is completely tightened.
After input of the programmed target torque TP and the programmed free speed SP in S 208 , the control 200 proceeds to S 210 . In S 210 , the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % are determined. In this embodiment, the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % are fixed values that are stored in a memory of the controller 102 or a computer connected to the controller 102 by the network interface 118 . In an exemplary embodiment of the invention, the percent of programmed torque at the start of ramping TSR % is 20%, the percent of programmed torque at the end of ramping TER % is 100% and the percent of rated speed at the end of ramping SER % is 20%.
After the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % are determined in S 210 , the control 200 proceeds to S 212 . In S 212 , the percent of programmed torque at the start of ramping TSR % is determined. In this embodiment, the percent of programmed torque at the start of ramping TSR % is a fixed value that is stored in a memory of the controller 102 or a computer connected to the controller 102 by the network interface 118 . In an exemplary embodiment of the invention, the percent of programmed torque at the start of ramping TSR % is 20%. The actual values for TER %, SER %, and TSR % may be preset in a variety of ways. Although the percentages TER %, SER % and TSR % have been described as fixed values stored in a memory of the controller 102 or a computer connected to the controller, it should be appreciated that a user may select from several discrete sets of fixed, preset values for TER %, SER %, and TSR %. The effect of these parameters on the performance of the tool 100 will also be discussed below with reference to the various examples.
After determining the percent of programmed torque at the start of ramping TSR % in S 212 , the control 200 proceeds to S 214 . In S 214 , the torque at the start of ramping TSR is calculated. The torque at the start of ramping TSR is calculated by multiplying the programmed target torque TP by the percent of programmed torque at the start of ramping TSR %, as in equation (1):
TSR=TP×TSR % (1).
The control 200 then proceeds to S 216 . In S 216 the torque at the end of ramping TER is calculated by multiplying the programmed target torque TP by the percent of programmed torque at the end of ramping TER %, as in equation (2):
TER=TP×TER % (2).
The control then proceeds to S 218 . In S 218 , the speed at the end of ramping SER is calculated by multiplying the rated speed SR by the percent of rated speed at the end of ramping SER %, as in equation (3):
SER=SR×SER % (3).
The control 200 then proceeds to S 220 . In S 220 the tool 100 is started. The tool 100 may either be started automatically by the controller 102 once S 218 is complete, or the tool may be started manually.
Once the tool 100 is started, the control proceeds to S 222 . In S 222 , the peak measured torque TPK of the tool 100 is determined. The controller 102 interrogates the sensor package 110 every millisecond, i.e., at a rate of 1 kHz, to read the current value of torque T applied by the tool 100 to the joint. As long as the torque T read by the sensor package 110 is increasing every millisecond, the peak measured torque TPK is equal to the torque T. However, as shown in FIGS. 7A and 7B, for example, between points 704 and 706 in FIGS. 7A and 7B the joint has a higher torque/turn rate and between points 706 and 707 the joint lower torque/turn rate than between points 704 and 706 . After point 707 , the torque/turn rate of the joint decreases and drops sharply at point 708 . The peak measured torque TPK, however, remains constant between points 707 and 708 . This allows the controller 102 to disregard small, momentary drops in the torque T. Further distinctions between the peak measured torque TPK and the torque T will be discussed below with reference to the various examples. It is understood that in order to determine the peak measured torque TPK, the controller 102 reads each incoming torque T from the sensor package 110 every millisecond to determine whether the torque T exceeds the value of the peak measured torque TPK that is stored in a memory of the controller 102 or a computer connected to the controller 102 .
After determining the peak measured torque TPK in S 222 , the control 200 proceeds to S 224 . In S 224 , it is determined whether the peak measured torque TPK is greater than or equal to the torque at the end of ramping TER. If the peak measured torque TPK is greater than or equal to the torque at the end of ramping TER (S 224 : Yes), the control proceeds to S 225 and it is determined if the peak measured torque TPK is greater than or equal to the programmed target torque TP. If the peak measured torque TPK is greater than or equal to the programmed target torque (S 225 : Yes), control 200 proceeds to S 226 and the tool 100 is stopped. The control 200 than proceeds to S 298 and ends. If the peak measured torque TPK is less than the programmed target torque TP (S 225 : No), control 200 returns to S 222 .
If the peak measured torque TPK is less than the torque at the end of ramping TER (S 224 : No), the control 200 proceeds to S 228 . In S 228 , it is determined whether the peak measured torque TPK is greater than or equal to the torque at the start of ramping TSR. If the peak measured torque TPK is not greater than or equal to the torque at the start of ramping TSR (S 228 : No), the control 200 returns to S 222 . If the peak measured torque TPK is greater than or equal to the torque at the start of ramping TSR (S 228 : Yes), the control 200 proceeds to S 232 .
Because of the configuration of most electric torque-applying tools, the controller 102 issues a series of speed commands SC. In a typical embodiment of the present invention, a speed command SC is issued to the tool 102 every millisecond. Before any speed ramp RAMPS begins, the controller 102 sets a time counter equal to zero. In S 232 , it is determined if the time counter is set to zero. If the time counter is set to zero (S 232 : Yes), the control 200 proceeds to S 234 where the speed at the start of the ramp SSR is set to the current speed SPEED as determined by the sensor package 110 . Control 200 then proceeds to S 236 . In S 236 , the slope of the speed ramp RAMPS is calculated, as in equation (4):
RAMPS=( SSR−SER )/( TER−TSR ) (4)
Equation (4) defines a linear speed ramp RAMPS based on the speed at the start of the ramp SSR, the speed at the end of the ramp SER, the torque at the end of the ramp TER and the torque at the start of the ramp TSR.
After calculating the speed ramp RAMPS in S 236 , the control 200 proceeds to S 238 and the time counter is incremented by a defined time period Δt, 1 ms in this embodiment, and control 200 proceeds to S 240 . In S 240 , a speed command SC is calculated, as in equation (5):
SC=SSR −RAMPS( TPK−TSR ) (5)
After calculation of the speed command in S 240 , control 200 proceeds to S 242 where the speed command SC is issued to the motor 104 to set the speed of the motor 104 to the value of the speed command SC. Control 200 then returns to S 222 .
As discussed above, the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % are fixed values in the control 200 . However, as the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % are fixed values, the control 200 has a potential for torque overshoot, especially on hard joints. Empirical testing has shown that the actual speed of the motor 104 at each 1 ms time interval is consistently higher than the speed command SC. This disparity occurs especially at high speeds, because the response time of a servo control loop implemented as the control 200 will allow the actual too speed to lag the speed command SC. Increasing the gains in the servo control loop can reduce this lag time, but high gains may cause the system to become unstable, resulting in undesired and damaging mechanical vibrations in the tool 100 .
However, if the percent of programmed torque at the end of ramping TER % is made variable, the torque at the end of ramping TER can be set to lower than 100% of the programmed torque TP, which provides leeway to correct for torque overshoot. The percent of the programmed torque at the end of ramping TER % is determined by examining the performance of a particular model of the tool 100 .
In a second embodiment of the present invention, the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % are variable. To promote ease of use and to prevent the user from selecting potentially incorrect or damaging values of the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER %, the controller 102 contains a number of discrete sets of the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % values, and the user chooses from among these discrete sets of values. For example, one set of values (also referred to as a “tightening level”) may specify that the percent of programmed torque at the end of ramping TER % is 60% of the programmed torque TP and the percent of rated speed at the end of ramping SER % is 20% of the tool's rated speed.
FIGS. 3A and 3B are flow diagrams illustrating a control 300 in accordance with the second embodiment of the present invention. Control 300 begins at S 302 , and control passes to S 304 , in which the tool electronics board 108 is interrogated to determine the capabilities of the tool 100 . Control then proceeds to S 306 . In S 306 , the controller 102 reads the user-defined programmed torque TP and programmed speed SP values. Control passes to S 308 .
In control 300 , the values of the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER % are not fixed values. During the programming of the controller 102 , the user is permitted to choose between one of two predetermined “tightening levels”, each level defining specific settings for the percent of programmed torque at the end of ramping TER % and the percent of rated speed at the end of ramping SER %. In this embodiment, the “level 1” settings are intended for applications where precise torque control is a high priority. In level 1, the percent of rated speed at the end of ramping SER % is set to a value of 20% of the tool's rated speed and the percent of programmed torque at the end of ramping TER % is determined based upon the programmed speed SP. In level 2, the percent of rated speed at the end of ramping SER % value is calculated based on the percent of the tool's rated torque. Level 2 settings are designed to reduce the time-to-torque and are useful for applications where precise torque control is not the highest priority.
If it is determined in S 308 that the user has selected level 1 tightening settings (S 308 :L 1 ), control passes to S 310 . In S 310 , the controller 102 determines the percent of programmed torque at the start of ramping TSR % in a manner identical to that of control 200 . Control 300 then passes to S 314 . In S 314 , the controller 102 calculates the torque at the start of ramping TSR as in control 200 . Control passes to S 318 .
In S 318 , the controller 102 calculates the value for the percent of programmed torque at the end of ramping TER %. In control 300 , the percent of programmed torque at the end of ramping TER % is calculated based on the programmed speed SP of the tool 100 . In an exemplary embodiment, if the tool's programmed speed is greater than a first speed, for example 2001 RPM, the percent of programmed torque at the end of ramping TER % is set to 20%. If, in this exemplary embodiment, the tool's programmed speed is less than a second speed, for example 501 RPM, the percent of programmed torque at the end of ramping TER % is set to 100%. Otherwise, the percent of programmed torque at the end of ramping TER % is calculated according equation (6):
TER %= C 1 · SP+C 2 (6)
In equation (6), C 1 is an empirically determined coefficient that is dependent on the various parameters of the tool, including, for example, the speed and torque rating of the motor and C 2 is an offset value. In an exemplary embodiment of the invention, C 1 is −0.04 and C 2 is 100. Control 300 then passes to S 322 , in which torque at the end of ramping TER is calculated as in control 200 . Control passes to S 326 .
In S 326 , the controller 102 reads the value of the percent of rated speed at the end of ramping SER %, which, for level 1 tightening, is set to a fixed value of 20%. Control 300 then passes to S 330 , in which the controller 102 calculates the speed at the end of ramping SER as in method 200 . Control 3300 then passes to S 334 , in which the tool 100 is started.
If the controller 102 determines that the user has selected tightening level 2 (S 308 :L 2 ), control 300 then proceeds sequentially through S 312 , S 316 , S 320 , S 324 , S 325 , S 328 , S 332 and S 334 . Of those blocks, only S 325 and S 328 differ from the functions described in the level 1 discussion above.
In S 325 , the controller 102 calculates the value of the percent of rated torque TP %, which is the ratio of the programmed target torque TP to the torque rating of the tool TR. Control 300 passes to S 328 .
In S 328 , the controller 102 calculates the value of the percent of rated speed at the end of ramping SER %. In level 1 tightening (S 326 ), the percent of rated speed at the end of ramping SER % is fixed at 20%. In level 2 tightening, the percent of rated speed at the end of ramping SER % is calculated by the controller 102 based upon the target torque percent of rated torque TP %, which is the ratio of the programmed target torque TP to the torque rating TR of the tool 100 . If the target torque percent of rated torque TP % is high, for example 90% or above, the tool 100 is being run close to capacity. However, if the target torque percent of rated torque TP %, is low, for example 50% or less, the tool is being run below capacity. The percent of rated speed at the end of ramping SER % is decreased as the target torque percent of rated torque TP % decreases because control of the tool at lower capacities is made more difficult due to the inertia of the tool 100 .
Referring to FIG. 8, the relationship between the percent of rated speed at the end of ramping SER % to the target torque percent of rated torque TP % is shown, i.e., the relationship between the rated speed at the end of ramping SER % to the capacity at which the tool 100 is used. At point X, the tool 100 is being operated at a level closer to its full capacity than at point Y. At point X, the target torque percent of rated torque TP % has a value M, for example 90%, and the percent of rated speed at the end of ramping SER % has a value Q, for example 30%. At point Y, the target torque percent of rated torque TP % has a value L, for example 50% and the percent of rated speed at the end of ramping SER % has a value P, for example 20%. The percent of rated speed at the end of ramping SER % is set according to equation (7):
SER %= R·TP %+ Z (7)
wherein R is the rate of change of the percent of rated speed at the end of ramping SER % to the target torque percent of rated torque TP %, which is defined as (Q−P)/(M−L), and Z is an offset value. In the example discussed above, R=0.25=(30−20)/(90−50) and Z=7.5. The percent of rated speed at the end of ramping SER % of the example discussed above thus equals 0.25·TP %+7.5.
It should be appreciated that the rate of change of the percent of rated speed at the end of ramping SER % to the target torque percent of rated torque TP % is empirically determined and depends on the paramaters of the tool 100 , including, for example, the speed and torque rating of the tool 100 . It should also be appreciated that the relationship between the percent of rated speed at the end of ramping SER % and the target torque percent of rated torque TP % may not be linear. The relationship may be defined by a stepwise function, for example.
Once the torque at the end of ramping TER and the speed at the end of ramping SER are determined, control 300 proceeds similarly to control 200 , i.e., the purpose and flow of blocks S 336 -S 398 generally correspond with blocks S 222 -S 298 of control 200 ; therefore, the discussion presented above with respect to blocks S 222 -S 298 of control 200 will suffice to describe the corresponding functional blocks of control 300 .
It should be understood that any appropriate values may be chosen for the parameters of controls 200 and 300 described above. The individual parameters that are used will vary with the type and characteristics of the tool and controller to which controls 200 and 300 are applied. In addition, some special considerations apply when controls 200 and 300 are applied to fluid powered tools. These considerations will be described in detail below.
The characteristics and advantages of the present invention will be further described with reference to the following examples. The examples illustrate exemplary results achieved using controls 200 and 300 on various types of soft, medium, hard and irregular joints. Examples 1-3 illustrate idealized versions of soft, medium, and hard joint for purposes of explanation and illustration. It is understood that in a production environment, most joints have at least some irregularity.
EXAMPLE 1
Soft Joint
FIGS. 4A and 4B illustrate Example 1, the control 200 as applied to an idealized soft joint. FIG. 4A shows a plot of time in milliseconds versus measured peak torque for a tool 100 employing control 200 and for a comparable tool without control 200 . Both tools are applied to a soft joint. In Example 1, the programmed torque is 40 Newton meters (Nm) and the programmed free speed is 760 RPM. The speed ramp for the tool using control 200 begins at point 400 and terminates at point 404 . The comparable tool without control 200 stops at point 402 . FIG. 4B is a plot of time versus tool speed in RPM, illustrating the speed profile of the two tools.
In FIGS. 4A and 4B, the joint is soft, therefore, the rate of torque application is very low, and consequently, there is very little torque overshoot in either the tool employing control 200 or the comparable tool. Note that for both tools the microprocessor in the controller takes approximately 2 ms after TP is reached to shut down the tool. This 2 ms time delay is not significant in Example 1 because the rate of torque application is very low. The use of control 200 does result in an approximately 20% increase in the time-to-torque, as is shown in FIGS. 4A and 4B, but this increase in time is not generally noticed by the user because the tightening process is completed in a fraction of a second.
EXAMPLE 2
Medium Joint
FIGS. 5A and 5B illustrate Example 2, the control 200 as applied to an idealized medium joint. FIG. 5A shows a plot of time in milliseconds versus measured peak torque for a tool 100 employing control 200 and for a comparable tool without control 200 . Both tools are applied to a medium joint. In Example 2, the programmed torque is 40 Newton meters (Nm) and the programmed free speed is 760 RPM. The speed ramp for the tool using control 200 begins at point 500 and terminates at point 502 . The comparable tool without control 200 stops at point 504 . FIG. 5B is a plot of time versus tool speed in RPM, illustrating the speed profile of the two tools.
As in the soft joint of Example 1, the rate of torque application in the medium joint is relatively low, and thus, there is substantially no torque overshoot in either tool. As in Example 1, the 2 ms delay imposed by the response time of the controller is not significant in either tool. In Example 2, use of control 200 causes a 25% increase in time-to-torque, but as in Example 1, this increased time-to-torque will likely go unnoticed by the user.
EXAMPLE 3
Hard Joint
The advantages of the present invention are most clearly seen in the case when a tool employing one of the controls 200 or 300 described above is used on a hard joint. FIGS. 6A and 6B illustrate Example 3, the use of tool 100 on an idealized hard joint. As in the previous Examples, both FIGS. 6A and 6B include data for a comparable tool used on the same joint without one of controls 200 and/or 300 of the present invention.
As is evident from both FIG. 6 A and FIG. 6B, the rate of torque application for a hard joint is about an order of magnitude greater than for a soft or medium joint, the fastening task is complete in just over 10 ms, rather than 100-200 ms. Because the rate of torque application is so great for a hard joint, torque overshoot is typically a problem, because the tool is usually spinning very quickly when the programmed torque is reached.
FIG. 6A clearly shows the typical torque overshoot in the comparable tool without controls 200 and 300 . In this Example, the programmed torque is 40 Nm, but the comparable tool, indicated at trace 600 , overshoots to 45 Nm because of the 2 ms delay caused by the response time of the microprocessor in the controller. This 2 ms delay is illustrated in FIG. 6A by dotted-line curve segment 602 .
By contrast, the tool using control 200 begins a speed ramp at point 604 and reaches the programmed torque at point 606 . As shown in FIG. 6B, the speed of the tool when TP is reached is only 152 RPM, about 25% of the speed of the comparable tool at TP. The 2 ms response delay of the controller for the tool using controls 200 and 300 results in a torque overshoot of only 1 Nm, as indicated by dotted-line segment 608 .
In the case of a hard joint, the speed at the beginning of the speed ramp for a tool 100 is greater than the speeds at the beginning of the speed ramps in soft and medium joints. This is because the rotational kinetic energy of the tool contributes a significant portion of the energy required to tighten a fastener into a hard joint.
EXAMPLE 4
Irregular Joint
Examples 1-3 show linear joints in which the amount of torque on the joint monotonically increases. However, joints are frequently irregular in their characteristics. FIG. 7A shows a typical time versus torque plot for a tool 100 using one of controls 200 and 300 applied to an irregular joint. In FIG. 7A, two sets of data are plotted, the measured torque values at each instant in time, and the peak torque values at each instant in time.
As was explained briefly above, controls 200 and 300 of the present invention use the measured peak torque (TPK) values to control speed ramping, rather than the measured torque values. This distinction is especially important in the case of irregular joints. In the irregular joint illustrated in FIG. 7A, the torque on the irregular joint increases linearly until point 704 (the controller begins a speed ramp at point 702 ). After point 704 , the torque on the joint increases nonlinearly until point 706 . Between point 706 and point 707 on the curve, the torque/turn rate of the joint decreases as the joint members yield and re-align. Between point 707 and point 708 , the joint experiences a momentary, sharp drop in torque/turn rate, during which the measured torque and peak torque values do not agree.
If controls 200 and 300 of the present invention used the measured torque values to control the speed ramp, the momentary drop in torque/turn rate at point 708 would cause the tool to speed up, an effect which would be undesirable. (As was explained earlier, quick changes in tool speed can cause the system to become unstable.) The use of the peak torque values eliminates this problem, as is made clear in FIG. 7 A. The irregular joint goes through several additional periods of variation in torque/turn rate before the speed ramp terminates at point 710 . FIG. 7B shows the corresponding time versus RPM plot. In FIG. 7B, the effect of the 2 ms controller response delay is visible as dotted-line segment 712 .
Use on Fluid Powered Tools
As was explained above, controls 200 and 300 of the present invention may be applied to fluid-powered tools, such as pneumatic and hydraulic torque-applying tools. However, fluid-powered tools differ somewhat from electric-powered tools, and may require some slight adaptations to controls 200 and 300 .
In fluid-powered tools, one known way of measuring the tool's rotational velocity is by installing an angular encoder in the fluid-powered tool. Control 200 or 300 could then be implemented using the fluid-powered tool. Note that fluid powered tools typically have longer response times than electric-powered tools, therefore, the parameters of controls 200 and 300 would need to be modified appropriately to compensate for the longer response times. Control 300 may be particularly suited to use in fluid-powered tools because of its greater adaptability.
As a further embodiment of the present invention, if an angle encoder is installed in either a fluid- or electric-powered tool, the angle encoder could be used to determine if a bolt has cross-threaded, or if other error conditions exist. For error detection with an angular encoder, the controller 102 would be programmed to expect that a fastening job will require a certain amount of rotation (e.g., 360 or 720 degrees). If a programmed torque is reached before the expected amount of rotation is achieved, it may indicate that a fastener has cross-threaded, or that the operator has tried to tighten the same bolt twice. Conversely, if the programmed torque is not reached after a large amount of rotation, it indicates that the fastener may be stripped. To implement error detection, the controller 102 would compare the amount of rotation with the TPK value, and would indicate error conditions as appropriate.
While the invention has been described by way of example embodiments, it is understood that the words which have been used herein are words of description, rather than words of limitation. Changes may be made within the purview of the appended claims without departing from the scope and spirit of the invention in its broader aspects. Although the invention has been described herein with reference to particular controls and embodiments, it is understood that the invention is not limited to the particulars disclosed. The invention extends to all appropriate equivalent structures, uses and mechanisms. | A method of controlling electric- and fluid-powered torque-applying tools to avoid torque overshoot and unwanted joint stresses. During a fastening operation, a controller monitors the peak torque applied to a joint at specified intervals in time and adjusts the speed of the tool appropriately to reach a programmed torque value without overshooting. The method may be applied to arbitrary types of joints and allows the tool to adapt to the characteristics of a joint while a fastening operation is underway, without a separate “learning” or “adaptation” phase. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
An optimum excitation frequency, which optimizes production of satellite ink drops (very small ink drops compared to the main ink drops) and stability of the ink disintegration phase, is automatically determined and relates also to an optimum excitation frequency setting method for the continuous jet type ink jet recording apparatus.
2. Description of the Related Art
Various Ink jet recording apparatus of the continuous jet type are conventionally known and practically used. An exemplary one of such conventional continuous jet type ink jet recording apparatus is disclosed, for example, in Japanese Patent Laid-Open Application No. Heisei 4-220350 and shown in FIG. 10. As presented in FIG. 10 the continuous jet type ink jet recording apparatus shown includes, as principal components thereof, a nozzle 1 having a circular orifice of a very small diameter, an ink electrode 2 for holding the potential of ink in the nozzle 1 at the ground level, an oscillator 3 in the form of a piezoelectric oscillator mounted on the nozzle 1, a control electrode 4 having a circular opening or a slit-like opening coaxial with the nozzle 1 and connected to receive a charge controlling signal to control charging of a jet of ink in accordance with image data, a grounding electrode 5 disposed in the rear (rightwardly in FIG. 10) of the control electrode 4 and grounded itself, a knife edge 6 mounted on the grounding electrode 5, a deflection power supply E1, a deflection electrode 7 connected to the deflection power supply E1 for cooperating with the grounding electrode 5 to produce therebetween an intense electric field perpendicular to an ink jet flying axis to deflect a charged ink drop to the grounding electrode 5 side, a reference oscillator CG for generating a reference clock signal CLK of an oscillation frequency instructed from a microprocessor unit (hereinafter referred to simply as MPU) not shown, a frequency divider FD for dividing the frequency of the reference clock signal CLK by N (positive integer) to produce an excitation signal PCLK, a delayed pulse generator DG for delaying the excitation signal PCLK to produce excitation signals PCLK of phases θ 0 , θ 1 , θ 2 , . . . , θ N-1 delayed to N (positive integer) stages in response to the reference clock signal CLK, a multiplexer MP for selecting one of the excitation signals PCLK of the thus delayed phases θ 0 , θ 1 , θ 2 , . . . , θ N-1 , an oscillation element driver VD for driving the oscillator 3 with the excitation signal PCLK of the phase θ selected by the multiplexer MP, a pulse width modulator PM for converting image data into a pulse width signal corresponding to a density gradation, a synchronizing circuit SC for synchronizing a rising or falling edge of the output of the pulse width modulator PM with a rising or falling edge of the excitation signal PCLK from the frequency divider FD, and a high voltage switch HVS for voltage amplifying and applying the output of the synchronizing circuit SC as a charge controlling signal to the control electrode 4. It is to be noted that reference character DR denotes a rotary drum around which a recording medium is wrapped.
In the conventional continuous jet type ink jet recording apparatus of the construction described above, the MPU variably sets the oscillation frequency of the reference clock signal CLK of the reference oscillator CG to variably set the excitation frequency of the excitation signal PCLK. The picture quality of a result of recording depends upon the ink disintegration characteristic of the nozzle 1, and the ink disintegration characteristic varies depending upon the excitation frequency of the excitation signal PCLK. Consequently, in the conventional continuous jet type ink jet recording apparatus, test images are printed successively varying the excitation frequency of the excitation signal PCLK and are checked for the picture quality by visual inspection, and an optimum excitation frequency is manually set from the outside (by means of an operation panel or the like) based on the visual check.
The conventional continuous jet type ink jet recording apparatus described above has two problems in terms of a manner of disintegration of an ink jet into ink drops from an ink column.
The first problem relates to a satellite drop which is produced between principal drops by the non-linearity of the surface deformation of an ink column. Three different modes are possible in regard to production of a satellite drop including a mode wherein a satellite drop produced is integrated with a succeeding principal drop, another mode wherein a satellite drop produced is integrated with a preceding principal drop, and a further mode wherein a satellite drop is not integrated until it comes to a recording surface. In continuous jet type ink jet recording apparatus, a still further mode wherein no satellite drop is produced is desirable. However, even if a satellite drop is produced, if it is integrated rapidly in the control electrode 4, it does not matter especially. However, when the integration occurs so late that a satellite drop is integrated in the rear of an exit of the control electrode 4 or no integration of a satellite drop occurs until it comes to a recording surface, the charged satellite drop (whose specific charge is usually higher than that of a charged principal drop) is influenced much by a deflection electric field and is deflected precedently to a charged principal drop. As a result, an electrostatic repulsive force from the satellite drop acts in a perpendicular direction to the ink jet flying axis upon the charged principal drop to obstruct correct deflection of the charged principal drop. Further, if the charged satellite drop is deflected out of a correct trajectory and integrated with a non-charged principal drop to be recorded, the noncharged principal drop is deflected a little. Any of the events described above deteriorates the picture quality very much. This problem will be hereinafter referred to as satellite drop problem.
The second problem is that the disintegration phase in (timing at) which an ink column is disintegrated into an ink drop is different among individual ink drops and is not stabilized with respect to the phase of the excitation signal PCLK. This small dispersion in disintegration phase at a disintegration point is amplified by an influence of the resistance of the air during flying of the ink drop and appears as a large fluctuation in position in the proximity or rearwardly of the knife edge 6. Further, the phase of the charge controlling signal during printing is kept fixed with reference to the phase of the excitation signal PCLK. If the disintegration phase varies in this condition, then not only the charging phase cannot be kept optimally, but also the measurement of the optimum charging phase suffers from an error. Such jet is defined as fuzzy jet. A fuzzy jet gives rise to, similarly to the satellite drop problem described above, significant reduction in picture quality because of production of an intermediate charged ink drop due to a fluctuation of the position of an ink drop in the ink jet axial direction and a fluctuation of the charging phase. This problem is defined as fuzzy jet problem.
Empirically, the two problems described above depend much upon the excitation frequency of the excitation signal PCLK. In particular, it is considered that the two problems depend upon the frequency characteristic of a mechanical oscillation system by which oscillations of the oscillator 3 mounted on the nozzle 1 are transmitted to the disintegration point of an ink jet.
In order to solve the problems described above, in a conventional continuous jet type ink jet recording apparatus, test images are printed successively varying the excitation frequency of the excitation signal PCLK and are checked by visual inspection to select an optimum excitation frequency, and the actual excitation frequency is manually set to the optimum excitation frequency. Therefore, the conventional continuous jet type ink jet recording apparatus is disadvantageous in that it is cumbersome that test images must be printed actually, that a criterion is very indefinite since it depends upon subjective visual observation of images, that setting of an excitation frequency which has been determined to be optimum is cumbersome because it is performed manually, and so forth.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a continuous jet type ink jet recording apparatus and an optimum excitation frequency setting method wherein an optimum excitation frequency against the satellite drop problem and the fuzzy jet problem is determined and an actual excitation frequency is automatically set to the optimum excitation frequency.
It is another object of the present invention to provide a continuous jet type ink jet recording apparatus including a plurality of nozzles to allow printing in color wherein an optimum excitation frequency is determined and an actual excitation frequency is automatically set to the optimum excitation frequency.
In order to attain the objects described above. according to an aspect of the present invention, there is provided a continuous jet type ink jet recording apparatus, comprising jet formation means for discharging pressurized ink as a continuous jet from a nozzle and successively disintegrating the continuous jet into ink drops of a uniform size in synchronism with excitation of an oscillator mounted on the nozzle. charging means for selectively charging the ink drops, deflection means for applying a deflection electric field perpendicular to a flying axis of the jet to an ink drop charged by the charging means to deflect the ink drop in a direction perpendicular to the jet flying axis, separation means for intercepting a charged ink drop deflected by the deflection means and allowing a straightforwardly advancing non-charged ink drop to pass thereby, variable frequency oscillation means for outputting an excitation signal for exciting the oscillator, switch means for switching the deflection electric field by the deflection means on and off, probe pulse generation means for generating a probe pulse signal in synchronism with the excitation signal outputted from the variable frequency oscillation means in a condition wherein the deflection electric field is controlled to an off state by the switch means, phase shifting means for shifting a phase of one of the excitation signal and the probe pulse signal with respect to a phase of the other, a conductive drop catcher for catching a charged ink drop charged by the probe pulse signal generated by the probe pulse generation means and having passed by the separation means, current detection means for detecting charge of charged ink drops caught by the conductive drop catcher as an electric current value, analog to digital conversion means for converting the electric current value detected by the current detection means into digital data, and optimum excitation frequency determination means for delivering an instruction to the variable frequency oscillation means to successively change an excitation frequency of the excitation signal to M stages, M being a positive integer, delivering another instruction to the phase shifting means to successively shift the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N with the excitation frequency at each of the stages, N being a positive integer, re-arranging the digital data obtained by the analog to digital conversion means in the order of the phases at each stage and storing the thus re-arranged data as jet current waveform data, extracting, based on the M sets of jet current waveform data thus stored, characteristics of the jet current waveforms at the individual stages to determine an optimum excitation frequency and delivering a further instruction to the variable frequency oscillation means to output an excitation signal of the optimum excitation frequency.
In the continuous jet type ink jet recording apparatus, the switch means switches the deflection electric field by the deflection means off, and the probe pulse generation means generates a probe pulse signal in synchronism with an excitation signal outputted from the variable frequency oscillation means in a condition wherein the deflection electric field is controlled to an off state by the switch means. Then, the phase shifting means shifts a phase of one of the excitation signal and the probe pulse signal with respect to a phase of the other, and the conductive drop catcher catches a charged ink drop charged by the probe pulse signal generated by the probe pulse generation means and having passed by the separation means. The current detection means detects charge of the charged ink drops caught by the conductive drop catcher as an electric current value, and the analog to digital conversion means converts the electric current value detected by the current detection means into digital data. Then, the optimum excitation frequency determination means delivers an instruction to the variable frequency oscillation means to successively change an excitation frequency of the excitation signal to M (positive integer) stages, delivers another instruction to the phase shifting means to successively shift the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2πN. (N is a positive integer) with the excitation frequency at each of the stages, re-arranges the digital data obtained by the analog to digital conversion means in the order of the phases at each stage and stores the thus re-arranged data as jet current waveform data, extracts, based on the M sets of jet current waveform data thus stored, characteristics of the jet current waveforms at the individual stages to determine an optimum excitation frequency and delivers a further instruction to the variable frequency oscillation means to output an excitation signal of the optimum excitation frequency.
Consequently, with the continuous jet type ink jet recording apparatus, the following advantages can be anticipated. In particular, the cumbersome operation of actually printing a test image can be eliminated. Further, since the criterion for the optimum excitation frequency is based on the detection value of the jet current, very accurate discrimination can be achieved. Furthermore, since determination of an optimum excitation frequency and setting of an actual excitation frequency to the optimum excitation frequency are automated, very simple and high speed operation can be achieved.
According to another aspect of the present invention, there is provided a continuous jet type ink jet recording apparatus, comprising n jet formation means each for discharging pressurized ink as a continuous jet from a nozzle and successively disintegrating the continuous jet into ink drops of a uniform size in synchronism with excitation of an oscillator mounted on the nozzle, n being an integer equal to or greater than 2, n charging means each for selectively charging the ink drops, deflection means for applying a deflection electric field perpendicular to flying axes of the jets to each ink drop charged by the charging means to deflect the ink drop in a direction perpendicular to the jet flying axis, separation means for intercepting a charged ink drop deflected by the deflection means and allowing a straightforwardly advancing non-charged ink drop to pass thereby, variable frequency oscillation means for outputting an excitation signal for commonly exciting the n oscillators, switch means for switching the deflection electric field by the deflection means on and off, probe pulse generation means for generating a probe pulse signal in synchronism with the excitation signal outputted from the variable frequency oscillation means in a condition wherein the deflection electric field is controlled to an off state by the switch means, n phase shifting means each for shifting a phase of one of the corresponding excitation signal and the probe pulse signal with respect to a phase of the other, a conductive drop catcher for catching a charged ink drop charged by the probe pulse signal generated by the probe pulse generation means and having passed by the separation means, current detection means for detecting charge of charged ink drops caught by the conductive drop catcher as an electric current value, analog to digital conversion means for converting the electric current value detected by the current detection means into digital data, and optimum excitation frequency determination means for delivering, successively for each of the n net formation means, an instruction to the variable frequency oscillation means to successively change an excitation frequency of the excitation signal to M stages, M being a positive integer, and then another instruction to the corresponding phase shifting means to successively shift the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N with the excitation frequency at each of the stages, N being a positive integer, re-arranging the digital data obtained in regard to each of the jet formation means by the analog to digital conversion means in the order of the phases at each stage and storing the thus re-arranged data as jet current waveform data, extracting, based on the nxM sets of jet current waveform data thus stored, characteristics of the jet current waveforms to determine an optimum excitation frequency and delivering a further instruction to the variable frequency oscillation means to output an excitation signal of the optimum excitation frequency.
In the continuous jet type ink jet recording apparatus, the switch means switches the deflection electric field by the deflection means off, and the probe pulse generation means generates a probe pulse signal in synchronism with an excitation signal outputted from the variable frequency oscillation means in a condition wherein the deflection electric field is controlled to an off state by the switch means. Each of the n phase shifting means shifts a phase of one of the corresponding excitation signal and the probe pulse signal with respect to a phase of the other, and the conductive drop catcher catches a charged ink drop charged by the probe pulse signal generated by the probe pulse generation means and having passed by the separation means. The current detection means detects the charge of the charged ink drops caught by the conductive drop catcher as an electric current value, and the analog to digital conversion means converts the electric current value detected by the current detection means into digital data. Then, the optimum excitation frequency determination means delivers, successively for each of the n net formation means, an instruction to the variable frequency oscillation means to successively change an excitation frequency of the excitation signal to M (positive integer) stages and then another instruction to the corresponding phase shifting means to successively shift the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N (N is a positive integer) with the excitation frequency at each of the stages, re-arranges the digital data obtained in regard to each of the jet formation means by the analog to digital conversion means in the order of the phases at each stage and stores the thus re-arranged data as jet current waveform data. Further, the optimum excitation frequency determination means extracts, based on the nxM sets of jet current waveform data thus stored, characteristics of the jet current waveforms to determine an optimum excitation frequency and delivers a further instruction to the variable frequency oscillation means to output an excitation signal of the optimum excitation frequency.
Consequently, also the continuous jet type ink jet recording apparatus is advantageous in that the cumbersome operation of actually printing a test image can be eliminated, that, since the criterion for the optimum excitation frequency is based on the detection value of the jet current, very accurate discrimination can be achieved, and that, since determination of an optimum excitation frequency and setting of an actual excitation frequency to the optimum excitation frequency are automated, very simple and high speed operation can be achieved.
According to a further aspect of the present invention, there is provided a continuous jet type ink jet recording apparatus, comprising n jet formation means each for discharging pressurized ink as a continuous jet from a nozzle and successively disintegrating the continuous jet into ink drops of a uniform size in synchronism with excitation of an oscillator mounted on the nozzle, n being an integer equal to or greater than 2, n charging means each for selectively charging the ink drops, deflection means for applying a deflection electric field perpendicular to flying axes of the jets to each ink drop charged by the charging means to deflect the ink drop in a direction perpendicular to the jet flying axis, separation means for intercepting a charged ink drop deflected by the deflection means and allowing a straightforwardly advancing non-charged ink drop to pass thereby, variable frequency oscillation means for outputting an excitation signal for commonly exciting the n oscillators, switch means for switching the deflection electric field by the deflection means on and off, probe pulse generation means for generating a probe pulse signal in synchronism with the excitation signal outputted from the variable frequency oscillation means in a condition wherein the deflection electric field is controlled to an off state by the switch means, n phase shifting means each for shifting a phase of one of the corresponding excitation signal and the probe pulse signal with respect to a phase of the other, n conductive drop catchers each for catching a charged ink drop charged by the probe pulse signal generated by the probe pulse generation means and having passed by the separation means, n current detection means each for detecting the charge of the charged ink drops caught by the corresponding conductive drop catcher as an electric current value, n analog to digital conversion means for converting the electric current values detected by the n current detection means into digital data, and optimum excitation frequency determination means for delivering, simultaneously for the n net formation means, an instruction to the variable frequency oscillation means to successively change an excitation frequency of the excitation signal to M stages, M being a positive integer, and then another instruction to each of the n phase shifting means to successively shift the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N with the excitation frequency at each of the stages, N being a positive integer, re-arranging the digital data obtained in regard to each of the jet formation means by the analog to digital conversion means in the order of the phases at each stage and storing the thus re-arranged data as jet current waveform data, extracting, based on the nxM sets of jet current waveform data thus stored, characteristics of the jet current waveforms to determine an optimum excitation frequency and delivering a further instruction to the variable frequency oscillation means to output an excitation signal of the optimum excitation frequency.
In the continuous jet type ink jet recording apparatus, the switch means switches the deflection electric field by the deflection means off, and the probe pulse generation means generates a probe pulse signal in synchronism with an excitation signal outputted from the variable frequency oscillation means in a condition wherein the deflection electric field is controlled to an off state by the switch means. Each of the n phase shifting means shifts a phase of one of the corresponding excitation signal and the probe pulse signal with respect to a phase of the other, and each of the n conductive drop catchers catches a charged ink drop charged by the probe pulse signal generated by the probe pulse generation means and having passed by the separation means. Each of the n current detection means detects the charge of charged ink the drops caught by the corresponding conductive drop catcher as an electric current value, and the n analog to digital conversion means convert the electric current values detected by the n current detection means into digital data. Then, the optimum excitation frequency determination means delivers, simultaneously for the n net formation means, an instruction to the variable frequency oscillation means to successively change an excitation frequency of the excitation signal to M (positive integer) stages and then another instruction to each of the n phase shifting means to successively shift the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N (N is a positive integer) with the excitation frequency at each of the stages, re-arranges the digital data obtained in regard to each of the jet formation means by the analog to digital conversion means in the order of the phases at each stage and stores the thus re-arranged data as jet current waveform data. Further, the optimum excitation frequency determination means extracts, based on the nxM sets of jet current waveform data thus stored, characteristics of the jet current waveforms to determine an optimum excitation frequency and delivers a further instruction to the variable frequency oscillation means to output an excitation signal of the optimum excitation frequency.
Consequently, also the continuous jet type ink jet recording apparatus is advantageous in that the cumbersome operation of actually printing a test image can be eliminated, that, since the criterion for the optimum excitation frequency is based on the detection value of the jet current, very accurate discrimination can be achieved, and that, since determination of an optimum excitation frequency and setting of an actual excitation frequency to the optimum excitation frequency are automated, very simple and high speed operation can be achieved.
According to a still further aspect of the present invention, there is provided an optimum excitation frequency setting method, comprising the steps of discharging pressurized ink as a continuous jet from a nozzle and successively disintegrating the continuous jet into ink drops of a uniform size in synchronism with excitation of an oscillator mounted on the nozzle, generating a probe pulse signal in synchronism with an excitation signal for the oscillator, charging an ink drop with the probe pulse signal thus generated, detecting charge of thus charged ink drops as an electric current value, converting the thus detected electric current value into digital data, and successively changing an excitation frequency of the excitation signal to M stages, M being a positive integer, successively shifting the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N with the excitation frequency at each of the stages, N being a positive integer, re-arranging the digital data obtained by the analog to digital conversion in the order of the phases at each stage and storing the thus re-arranged data as jet current waveform data, extracting, based on the M sets of jet current waveform data thus stored, characteristics of the jet current waveforms at the individual stages to determine an optimum excitation frequency, and outputting an excitation signal of the optimum excitation frequency.
The optimum excitation frequency setting method is advantageous in that, since the criterion for the optimum excitation frequency is based on the detection value of the jet current, very accurate discrimination can be achieved.
According to a yet further aspect of the present invention, there is provided an optimum excitation frequency setting method, comprising the steps of discharging pressurized ink as a continuous jet from each of n nozzles an d successively disintegrating the continuous jet into ink drops of a uniform size in synchronism with excitation of an oscillator mounted on each of the nozzles, n being an integer equal to or greater than 2, generating a probe pulse signal in synchronism with an excitation signal for the oscillator, charging an ink drop with the probe pulse signal thus generated, detecting the charge of thus charged ink drops as an electric current value, converting the thus detected electric current value into digital data, and successively changing, successively for each of the n nozzles, an excitation frequency of the excitation signal to M stages, M being a positive integer, and successively shifting the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N with the excitation frequency at each of the stages, N being a positive integer, rearranging the digital data obtained in regard to each of the n nozzles by the analog to digital conversion in the order of the phases at each stage and storing the thus re-arranged data as jet current waveform data, extracting, based on the nxM sets of jet current waveform data thus stored, characteristics of the jet current waveforms at the individual stages to determine an optimum excitation frequency, and outputting an excitation signal of the optimum excitation frequency.
Also the optimum excitation frequency setting method is advantageous in that, since the criterion for the optimum excitation frequency is based on the detection value of the jet current, very accurate discrimination can be achieved.
According to a yet further aspect of the present invention, there is provided an optimum excitation frequency setting method, comprising the steps of discharging pressurized ink as a continuous jet from each of n nozzles and successively disintegrating the continuous jet into ink drops of a uniform size in synchronism with excitation of an oscillator mounted on each of the nozzles, n being an integer equal to or greater than 2, generating a probe pulse signal in synchronism with an excitation signal for the oscillator, charging an ink drop with the probe pulse signal thus generated, detecting the charge of thus charged ink drops as an electric current value, converting the thus detected electric current value into digital data, and successively changing, simultaneously for the n nozzles, an excitation frequency of the excitation signal to M stages, M being a positive integer, and successively shifting the phase of one of the excitation signal and the probe pulse signal with respect to the phase of the other by 2π/N with the excitation frequency at each of the stages, N being a positive integer, re-arranging the digital data obtained in regard to each of the n nozzles by the analog to digital conversion in the order of the phases at each stage and storing the thus re-arranged data as jet current waveform data, extracting, based on the nxM sets of jet current waveform data thus stored, characteristics of the jet current waveforms at the individual stages to determine an optimum excitation frequency, and outputting an excitation signal of the optimum excitation frequency.
Also the optimum excitation frequency setting method is advantageous in that, since the criterion for the optimum excitation frequency is based on the detection value of the jet current, very accurate discrimination can be achieved.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference characters.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a general construction of a continuous jet type ink jet recording apparatus to which the present invention is applied;
FIG. 2 is a time chart illustrating outputs of a frequency divider, a probe pulse generator and a delay pulse generator shown in FIG. 1;
FIG. 3 is a graph showing a jet current waveform obtained by plotting values of jet current measured on the continuous jet type ink jet recording apparatus of FIG. 1;
FIG. 4 is a graph illustrating a normal jet current waveform and another jet current waveform, which suffers from the satellite drop problem, measured on the continuous jet type ink jet recording apparatus of FIG. 1;
FIG. 5 is a graph illustrating a stable jet current waveform and another jet current waveform, which suffers from the fuzzy jet problem, measured with on the continuous jet type ink jet recording apparatus of FIG.
FIG. 6 is a flow chart illustrating an optimum excitation frequency determination process executed by an MPU shown in FIG. 1;
FIG. 7 is a block diagram showing a general construction of another continuous jet type ink jet recording apparatus to which the present invention is applied;
FIG. 8 is a similar view but showing a general construction of a further continuous jet type ink jet recording apparatus to which the present invention is applied;
FIG. 9 is a flow chart illustrating an optimum excitation frequency determination process executed by an MPU shown in FIG. 8; and
FIG. 10 is a block diagram showing a general construction of a conventional continuous jet type ink jet recording apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, there is shown a continuous jet type ink jet recording apparatus to which the present invention is applied. The continuous jet type ink jet recording apparatus shown includes, as principal components thereof, a nozzle 1 having a circular orifice of a very small diameter, an ink electrode 2 for holding the potential of ink in the nozzle 1 at the ground level, an oscillator 3 in the form of a piezoelectric oscillator mounted on the nozzle 1, a control electrode 4 having a circular opening or a slit-like opening coaxial with the nozzle 1 and connected to receive a charge controlling signal to control charging of a jet of ink in accordance with image data, a grounding electrode 5 disposed in the rear of the control electrode 4 and grounded itself, a knife edge 6 mounted on the grounding electrode 5, a deflection power supply E1, a deflection electrode 7 connected to the deflection power supply E1 for cooperating with the grounding electrode 5 to produce therebetween an intense electric field perpendicular to an ink jet flying axis to deflect a charged ink drop to the grounding electrode 5 side, a switch SW1 for switchably connecting the deflection electrode 7 to the deflection power supply E1 or the ground, a reference oscillator CG for generating a reference clock signal CLK of an oscillation frequency instructed from an MPU 10, a frequency divider FD for dividing the frequency of the reference clock signal CLK by N (positive integer) to produce an excitation signal PCLK, a delayed pulse generator DG for delaying the excitation signal PCLK to N (positive integer) stages in response to the reference clock signal CLK to produce pulse trains θ 0 , θ 1 , θ 2 , . . . , θ N-1 , a multiplexer (2) MP2 for selecting one of the delayed pulse trains θ 0 , θ 1 , θ 2 , . . . θ N-1 , an oscillation element driver VD for driving the oscillator 3 with the pulse signal selected by the multiplexer (2) MP2, a pulse width modulator PM for converting image data into a pulse width signal corresponding to a density gradation, a probe pulse generator PG for generating a probe pulse signal having a pulse width sufficiently shorter than the period of the excitation signal PCLK in synchronism with a rising or falling edge of the excitation signal PCLK, a synchronizing circuit SC for synchronizing a rising or falling edge of the output of the pulse width modulator PM with a rising or falling edge of the excitation signal PCLK from the frequency divider FD, a multiplexer (1) MP1 for selecting one of the probe pulse signal from the probe pulse generator PG and the output of the synchronizing circuit SC, a high voltage switch HVS for voltage amplifying and applying the output of the multiplexer (1) MP1 as a charge controlling signal to the control electrode 4, a conductive drop catcher 8 disposed at a position (hereinafter referred to as home position) in a region, which does not participate in recording, rearwardly of the grounding electrode 5 and the deflection electrode 7 and serving also as a detection electrode, a shield line 9 having an end connected to the conductive drop catcher 8, a current detector (current to voltage converter) CD for measuring the charge of ink drops discharged from an ink jet to the conductive drop catcher 8, an analog to digital (A/D) converter ADC for converting the output of the current detector CD from an analog signal into a digital signal, and the MPU 10 for controlling the reference oscillator CG to oscillate with an oscillation frequency of the reference clock signal CLK in response to the output of the analog to digital converter ADC. It is to be noted that the MPU 10 also controls the entire system of the continuous jet type ink jet recording apparatus of the present embodiment.
The reference oscillator CG oscillates the reference clock signal CLK in response to an instruction from the MPU 10 so that the oscillation frequency thereof is set to one of frequencies f 0 , f 1 , f 2 , f 3 , . . . , fM-1 obtained by dividing a frequency band ranging within ±5% to ±10% from a center frequency equally by M (positive integer).
The delayed pulse generator DG is formed from, for example, an N-bit shift register of the serial-in parallel-out type.
The probe pulse generator PG is formed from, for example, a monostable multivibrator triggered by an edge of the excitation signal PCLK.
The current detector CD is formed from an integration circuit. The current detector CD has an integration time, for example, longer than 2×10 4 times the disintegration period. Consequently, the current detector CD detects accumulated charge of more than 2×10 4 ink drops (refer to Japanese Patent Laid-Open Application No. Heisei 4-144753).
Subsequently, operation of the continuous jet type ink jet recording apparatus of the first embodiment having the construction described above will be described. It is to be noted that this operation is executed when a carriage (not shown) on which the nozzle 1 is carried is at its home position and a process prepared in advance for automatically setting an optimum excitation frequency is started.
First, ink is pressurized by an ink pump (not shown) and introduced into the nozzle 1 through an ink tube (not shown) so that a jet of the ink is jetted from the nozzle 1. Thereafter, the ink jet is continuously jetted in a steady condition. Then, the MPU 10 switches the switch SW1 to the grounding side to ground the deflection electrode 7. Consequently, the deflection electric field between the grounding electrode 5 and the deflection electrode 7 is turned off. As a result, also a charged ink drop is thereafter allowed to pass by the knife edge 6. Further, the MPU 10 controls the multiplexer (1) MP1 to select the output of the probe pulse generator PG.
In this condition, the MPU 10 successively delivers instructions of the following operations to set an oscillation frequency of the reference clock signal CLK of the reference oscillator CG to optimize the excitation frequency of the excitation signal PCLK.
1 The oscillation frequency of the reference clock signal CLK is set to f 0 , and the jet current waveform (charging characteristic of the jet) at f 0 is measured by the following procedure.
The reference oscillator CG outputs the reference clock signal CLK. The reference clock signal CLK is divided by N in frequency by the frequency divider FD and inputted as the excitation signal PCLK to the delayed pulse generator DG, probe pulse generator PG and synchronizing circuit SC. In particular, the excitation frequency PCLK of the excitation signal PCLK (in the following description, a signal and its frequency may be denoted by the same reference characters) is CLK/N (for example, CLK=16 MHz, N=16, PCLK=1 MHz).
The delayed pulse generator DG receives the excitation signal PCLK and the reference clock signal CLK as input data and an input shift clock signal, respectively, and outputs N pulse trains θ 0 , θ 1 , θ 2 , . . . , θ N-1 having a period of the excitation signal PCLK successively delayed by 2π/N. One of the N pulse trains θ 0 , θ 1 , θ 2 , . . . , θ N-1 is selected by the multiplexer (2) MP2 under the control of the MPU 10 and outputted to the oscillation element driver VD. The oscillation element driver VD excites the oscillator 3 in response to the output of the multiplexer (2) MP2. Consequently, the ink jet jetted from the nozzle 1 is disintegrated into a drop in synchronism with the excitation by the oscillator 3.
The probe pulse generator PG generates, in synchronism with a rising or falling edge (same one as that upon recording) of the excitation signal PCLK, a probe pulse signal having a pulse width sufficiently shorter than the period of the excitation signal PCLK (for example, when the period of the excitation signal PCLK is 1 μsec (oscillation by 1 MHz), the pulse width is 0.1 to 0.3 μsec).
The probe pulse signal outputted from the probe pulse generator PG is inputted via the multiplexer (1) MP1 to the high voltage switch HVS, by which it is voltage amplified and applied as a charge controlling signal to the control electrode 4. Accordingly, an ink drop disintegrated in synchronism with the excitation of the oscillator 3 is charged in response to the probe pulse signal. Now, since the polarity of the probe pulse signal is the negative, an ink drop is usually charged, but only within a time within which the probe pulse signal is applied as a controlling signal to the control electrode 4 (for example, 0.1 to 0.3 μsec), the charging voltage is controlled to an off state.
An ink drop charged by the control electrode 4 is not deflected since the deflection electric field is in an off state, and passes by the knife edge 6 and is caught by the conductive drop catcher 8 at the home position which is in an isolated condition from any other element.
Charge of charged ink drops caught by the conductive drop catcher 8 flow as jet current I j through the shield line 9 and appears as a voltage at the output of current detector CD. The voltage converted from the jet current I j is then converted into digital data by the analog to digital converter ADC and outputted to a data bus of the MPU 10.
Measurement of the jet current I j is performed for the individual phases in such a manner that, as seen in FIG. 2, the MPU 10 successively switches the multiplexer (2) MP2 so that the oscillator 3 is successively driven with the pulse trains θ 0 , θ 1 , θ 2 , . . . , θ N-1 having phases successively delayed by 2πi/N (i=0, 1, 2, . . . , N-1) with respect to the excitation signal PCLK to excite the nozzle 1.
Values of the jet current I j measured for the individual phases are converted from analog into digital values by the analog to digital converter ADC and individually stored into the memory (not shown) of the MPU 10.
FIG. 3 is a graph showing a jet current waveform obtained by plotting values of the jet current I j measured for each phase using a probe pulse signal. As shown in FIG. 3, whether or not an intermediately charged ink drop is present is determined by stroboscope observation using a microscope, and the mark ◯ represents absence of an intermediately charged ink drop while the mark represents presence of an intermediately charged ink drop. That a result of the measurement exhibits such a tendency as seen in FIG. 3 is described in detail in Johan Nilsson, "Applications of Micro Drops", Dept. of Electrical Measurements, Lund Inst. of Technology, Report 6/1993, pp. 90-101. Further, a technique of measuring the jet current I j is disclosed in detail in Japanese Patent Laid-Open Application No. Heisei 4-144753 by the inventor of the present invention.
2 Thereafter, the MPU 10 successively sets the oscillation frequency of the reference clock signal CLK of the reference oscillator CG to f 1 , f 2 , f 3 , . . . , f M-1 and measures the jet current waveform with each of the oscillation frequencies in a similar manner as described above.
3 After the measurement of M sets of jet current waveform data with the oscillation frequencies f 0 , f 1 , f 2 , f 3 , . . . , f M-1 is completed, the MPU 10 extracts characteristics of the jet current waveforms based on the M sets of jet current waveform data stored in the memory, determines an optimum excitation frequency of the excitation signal PCLK, and sets the oscillation frequency of the reference clock signal CLK of the reference oscillator CG to the optimum excitation frequency. In particular, since whether or not the satellite drop problem and the fuzzy jet problem actually occur can be determined empirically from the shape of a jet current waveform, the MPU 10 extracts, from the M sets of jet current waveform data, excitation frequencies with which no satellite drop is produced or with which, even if a satellite drop is produced, it is integrated rapidly in the control electrode 4 and has no bad influence on a principal drop. Then, the MPU 10 discriminates, from among the thus extracted excitation frequencies, an excitation frequency with which the disintegration phase is most stable (most non-fuzzy), and determines the thus discriminated excitation frequency as an optimum excitation frequency.
FIG. 4 is a graph which shows a normal jet current waveform (A) which does not suffer from the satellite drop problem and jet current waveforms (B) and (C) which suffer from the satellite drop problem. The normal jet current waveform (A) exhibits a simple waveform which has a single maximum point (highest point) and a single minimum point (lowest point). Further, when the phase is successively delayed like θ N-1 →θ N-2 →. . . →θ 1 →θ 0 , the maximum point appears later than and comparatively in the proximity of (small in phase difference from) the minimum point. In the normal jet current waveform (A), the maximum point corresponds to the disintegration phase of a principal drop. On the other hand, the jet current waveform (B). which suffers from the satellite drop problem, includes two maximum points and two minimum points. When the phase is successively delayed like θ N-1 →θ N-2 →. . . →θ 1 →θ 0 , the maximum point which appears subsequently to the lowest point is the disintegration phase point of a principal drop, and the highest point appears after the other minimum point next to the maximum point. In the meantime, the jet current waveform (C) which suffers from the satellite drop problem includes a single maximum point (highest point) and a single minimum point (lowest point), which, however, are spaced away by a very long distance from each other (large in phase difference between them). When the phase is successively delayed like θ N-1 →θ N-2 →. . . →θ 1 →θ 0 , the maximum point appears at a position spaced rearwardly by a large distance (with a great phase difference) from the minimum point. This maximum point does not correspond to the disintegration phase of a principal drop. It is to be noted that the jet current waveform (C) which suffers from the satellite drop problem can be regarded as that of a case wherein the jet current waveform (B) which suffers from the satellite drop problem does not include the minor minimum point. In order to extract only the normal jet current waveform (A) from among the three kinds of jet current waveforms (A), (B) and (C), for example, the minimum point is found out first, and then the phase is successively delayed from the point. In this instance, it can be determined that, if the maximum point is found out successfully within a fixed range in phase from the point, then the jet current waveform is normal (normal jet current waveform (A)), but in any other case, the jet current waveform is not normal and may be the jet current waveform (B) or (C). The fixed range in phase can be determined empirically.
FIG. 5 is a graph showing a jet current waveform (A) which exhibits a stable disintegration phase and another jet current waveform (D) which exhibits an unstable disintegration phase (fuzzy jet). Since the current detector CD is formed from an integration circuit, comparing with the jet current waveform (A) which exhibits a stable disintegration phase, the jet current waveform (D) which exhibits an unstable disintegration phase presents a lower contrast ΔI j which is a difference between the highest value and the lowest value of the jet current I j (ΔI j (D)<ΔI j (A)).
From the foregoing, those jet current waveforms which suffer from the satellite drop problem are first removed from the M sets of jet current waveforms, and then from among the remaining jet current waveforms, a jet current waveform which exhibits the highest contrast ΔI j is determined. The excitation frequency of the thus determined jet current waveform is an optimum excitation frequency (criterion for the optimum excitation frequency).
FIG. 6 is a flow chart illustrating an optimum excitation frequency determination process executed by the MPU 10 based on the criterion for the optimum excitation frequency described above. As shown in FIG. 6, the optimum excitation frequency determination process includes a current waveform data extraction step S101, a jet current lowest value corresponding phase extraction step S102, a jet current maximum value corresponding phase extraction step S103, a phase difference discrimination step S104, a jet current minimum value corresponding phase extraction step S105, a lowest value corresponding phase/minimum value corresponding phase comparison step S106. a contrast storage step S107, an excitation frequency highest discrimination step S108, an excitation frequency increment step S109, and an optimum excitation frequency determination step S110.
Operation of the MPU 10 in the optimum excitation frequency determination process will be described below with reference to FIG. 6.
First, the MPU 10 extracts current waveform data of an excitation frequency f K (beginning with K=0) (step S101), and extracts a phase θ min corresponding to the lowest value I j (min) of the jet current I j (step S102).
Then, the MPU 10 successively moves the phase in a direction in which the excitation signal PCLK is delayed with respect to a probe pulse signal (θ N-1 →θ 0 ) to extract a phase θ max with which the jet current I j exhibits a maximum value (step S103).
Thereafter, the MPU 10 discriminates whether or not the difference θ max -θ min is smaller than a prescribed value Δθ s determined empirically (step S104). If the phase difference is not smaller, then the excitation frequency f K is incremented by one (step S109), and then the MPU 10 returns its control to step S101 to examine the data for the next sucessive waveform.
If the difference θ max -θ min is smaller than the prescribed value Δθ s in step S104, then the MPU 10 successively moves the phase in a direction in which the excitation signal PCLK is delayed with respect to the probe pulse signal (θ N-1 →θ 0 ) to extract a phase θ' min with which the jet current I j exhibits a minimum value I j ' (min) (step S105).
Then, the MPU 10 discriminates whether or not θ' min is equal to θ min (step S106). If θ' min is not equal to θ min , then the MPU 10 increments the excitation frequency f K by one step (step S109) and returns the control to step S101.
If θ' min is equal to θ min in step S106, the MPU 10 stores the difference ΔI j =I j (max)-I j (min) as a contrast at the excitation frequency f K into the memory (step S107).
Thereafter, the MPU 10 discriminates whether or not the excitation frequency f K is equal to the highest excitation frequency f M-1 (step S108). If the excitation frequency f K is not equal to the highest excitation frequency f M-1 , then the MPU 10 increments the excitation frequency f K by one step (step S109) and then returns the control to step S101.
If the excitation frequency f K is equal to the highest excitation frequency f M-1 in step S108, then the MPU 10 searches the contrasts ΔI j stored in the memory for the highest value ΔI j (max) and determines the excitation frequency f K corresponding to the maximum value Δ Ij (max) as an optimum excitation frequency f opt (step S110), thereby ending the process.
After the optimum excitation frequency f opt is determined in this manner, the MPU 10 delivers an instruction to the reference oscillator CG to oscillate with an optimum excitation frequency N·f opt corresponding to the optimum excitation frequency f opt .
It is to be noted that, if the MPU 10 thereafter switches the switch SW1 to the deflection power supply E1 side, switches the multiplexer (1) MP1 to select the output of the synchronizing circuit SC and switches the multiplexer (2) MP2 to select the appropriate excitation phase, then the continuous jet type ink jet recording apparatus enters a printing mode.
As shown in FIG. 7, there is shown in block diagram a general construction of another continuous jet type ink jet recording apparatus to which the present invention is applied. The continuous jet type ink jet recording apparatus of the present embodiment is a modification to and basically similar in construction to the continuous jet type ink jet recording type of the preceding embodiment of FIG. 1, and overlapping description of the common construction is omitted here to avoid redundancy.
The continuous jet type ink jet recording apparatus of the present embodiment is basically different from the continuous jet type ink jet recording type of the preceding embodiment in that, while the continuous jet type ink jet recording apparatus of the first embodiment delays, upon designation of the phase of the charge controlling signal with respect to the disintegration phase for an ink jet, the excitation signal PCLK to designate the phase, the continuous jet type ink jet recording apparatus delays the charge controlling signal to designate the phase. In particular, in the continuous jet type ink jet recording apparatus of the present embodiment, the excitation signal PCLK is inputted directly to the oscillation element driver VD while the output signal of the multiplexer (2) MP2 is inputted to the probe pulse generator PG and the synchronizing circuit SC. Accordingly, all of the components of the continuous jet type ink jet recording apparatus of the present embodiment are common and correspond to all of the components of the continuous jet type ink jet recording apparatus of the first embodiment.
Also in the continuous jet type ink jet recording apparatus of the present embodiment constructed in this manner, although it is different in that the jet current I j is measured successively displacing the phase of the probe pulse signal by 2π/n, jet current waveform data are obtained for the excitation frequencies f 0 , f 1 , f 2 , f 3 , . . . , f M-1 similarly as in the continuous jet type ink jet recording apparatus of the first embodiment described hereinabove with reference to FIG. 1. In this instance, however, since the displacement in phase between the excitation signal PCLK and the charge controlling signal is reversed, the jet current waveforms are symmetrical (mirror images) to those of FIGS. 3 to 5 in regard to the leftward and rightward directions. Further, since the process of extracting characteristics of jet current waveforms to determine an optimum excitation frequency can be inferred readily from the description of the continuous jet type ink jet recording apparatus of the first embodiment, detailed description thereof is omitted here.
Referring now to FIG. 8, there is shown in block diagram a general construction of a further continuous jet type ink jet recording apparatus to which the present invention is applied. The continuous jet type ink jet recording apparatus of the present embodiment is constructed as a modification to and basically similar in construction to the continuous jet type ink jet recording type of the preceding embodiment of FIG. 1, and overlapping description of the common construction is omitted here to avoid redundancy.
The continuous jet type ink jet printer of the present embodiment, however, is constructed as a continuous jet type ink jet recording apparatus which can print in color and, to this end, includes a plurality of nozzles 1. Thus, the continuous jet type ink jet recording apparatus of the present embodiment includes, independently for the four individual colors of C (cyan), M (magenta), Y (yellow) and BK (black), the components of the continuous jet type ink jet recording apparatus of the first embodiment shown in FIG. 1 except the reference oscillator CG, frequency divider FD, grounding electrode 5, knife edge 6, deflection electrode 7, deflection power supply E1, switch SW1, delayed pulse generator DG, probe pulse generator PG, conductive drop catcher 8, shield line 9, current detector CD, analog to digital converter ADC and MPU 10. It is to be noted that, if also the reference oscillator CG and the frequency divider FD are provided for each of the four colors individually independently of each other, the number of ink drops to be produced per unit time becomes different among the individual colors, and this is not preferable for a color-printable continuous jet type ink jet recording apparatus which controls the amounts of inks of the four colors to be applied to a recording medium to represent information in color.
In the continuous jet type ink jet recording apparatus having the construction described above, jet current waveform data (data quantity: 4M) are first measured with the excitation frequencies f 0 , f 1 , f 2 , f 3 , . . . , f M-1 for the the four nozzles 1 independently of each other, and then, if any one of the four nozzle 1 has exhibited a jet current waveform which suffers from the satellite drop problem, an excitation frequency or frequencies with which the nozzle 1 suffers from the satellite drop problem are excepted also with regard to the other three nozzles 1. Then, based on the remaining jet current waveforms, an excitation frequency with which the lowest value ΔI j (min) exhibits the highest value among the four sets of contrasts ΔI j corresponding to the four nozzles 1 is determined as an optimum excitation frequency (criterion for the optimum excitation frequency).
FIG. 9 illustrates in flow chart an optimum excitation frequency determination process executed by the MPU 10 based on the criterion for the optimum excitation frequency described above. As shown in FIG. 9, the optimum excitation frequency determination process includes a nozzle number 1 setting step S200, a current waveform data extraction step S201, a jet current lowest value corresponding phase extraction step S202, a jet current maximum value corresponding phase extraction step S203, a phase difference discrimination step S204, a jet current minimum value corresponding phase extraction step S205, a lowest value corresponding phase/minimum value corresponding phase comparison step S206, a contrast storage step S207, an excitation frequency highest value determination step S208, an excitation frequency increment step S209, a nozzle number 4 discrimination step S210, a nozzle number increment step S211, a contrast lowest value extraction step S212, and an optimum excitation frequency determination step S213.
Here, operation of the MPU 10 in the optimum excitation frequency determination process will be described with reference to FIG. 9.
First, the MPU 10 sets the nozzle number n to 1 (step S200), extracts current waveform data of the excitation frequency f K (beginning with K=0) (step S201) and extracts a phase θ min corresponding to the lowest value I j (min) of the jet current I j (step S202).
Then, the MPU 10 successively moves the phase in a direction in which the excitation signal PCLK is delayed with respect to a probe pulse signal (θ N-1 →θ 0 ) to extract a phase θ max with which the jet current I j exhibits a maximum value (step S203).
Thereafter, the MPU 10 discriminates whether or not the difference θ max -θ min is smaller than a prescribed value Δθ s determined empirically (step S204). If the difference is not smaller, then the excitation frequency f K is incremented by one step (step S209), and then the MPU 10 returns its control to step S201.
If the difference θ max -θ min is smaller than the prescribed value Δθ s in step S204. then the MPU 10 successively moves the phase in a direction in which the excitation signal PCLK is delayed with respect to the probe pulse signal (θ N-1 .sub.→θ 0 ) to extract a phase θ' min with which the jet current I j exhibits a minimum value I j ' (min) (step S205).
Then, the MPU 10 discriminates whether or not θ' min is equal to θ min (step S206). If θ' min is not equal to θ min , then the MPU 10 increments the excitation frequency f K by one step (step S209) and returns the control to step S201.
If θ' min is equal to θ min in step S206, then the MPU 10 stores the difference ΔI j =I J (max)-I j (min) as a contrast at the excitation frequency f K into the memory (step S207).
Thereafter, the MPU 10 discriminates whether or not the excitation frequency f K is equal to the highest excitation frequency f M-1 (step S208). If the excitation frequency f K is not equal to the highest excitation frequency f M-1 , then the MPU 10 increments the excitation frequency f K by one step (step S209) and then returns the control to step S201.
If the excitation frequency f K is equal to the highest excitation frequency f M-1 in step S208, then the MPU 10 discriminates whether or not the nozzle number n is equal to 4 (step S210). If the nozzle number n is not equal to 4, then the MPU 10 increments the nozzle number n by one (step S211) and returns the control to step S201. Consequently, the operations in steps S201 to S208 described above are repeated by a number of times equal to the number of the nozzles 1.
If it is discriminated in step S210 that the nozzle number n is equal to 4, then the MPU 10 searches the contrasts ΔI j stored in the memory for the lowest values ΔI j (min) for the individual nozzles 1 from among the contrasts ΔI j whose excitation frequencies f K are common among the nozzles 1, and stores the lowest values ΔI j (min) into the memory (step S212). Then, the MPU 10 determines the excitation frequency f K corresponding to the minimum value ΔI j (min) of the highest contrast ΔI j from among the stored minimum values ΔI j (min) of the contrasts ΔI j as an optimum excitation frequency f opt (step S213), thereby ending the process.
By the way, in the continuous jet type ink jet recording apparatus of the third embodiment shown in FIG. 8, since the conductive drop catcher 8, shield line 9, current detector CD and analog to digital converter ADC are provided commonly for the plurality of nozzles 1, jet current waveforms from the nozzles 1 are measured in a time series. However, if the conductive drop catcher 8, shield line 9, current detector CD and analog to digital converter ADC are provided for each of the nozzles 1, then jet current waveforms can be measured in parallel, and the measurement time is reduced remarkably.
It is to be noted that the construction wherein the charge controlling signal is delayed with respect to the excitation signal PCLK as in the continuous jet type ink jet recording apparatus of the second embodiment shown in FIG. 7 can naturally be applied similarly to the continuous jet type ink jet recording apparatus of the third embodiment which employs the plurality of nozzles 1.
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein. | The optimum excitation frequency for forming successive ink drops in an ink jet printer is determined by forming a sequence of ink drops at a plurality of different drop-formation frequencies and phases thereof and integrating a detected current representative of the value of the charge on the ink drops as a function of time for each the plural frequencies and phases thereof to create a corresponding plurality of waveforms. The frequency of the optimum waveform, which minimizes the undesired formation of satellite ink drops and undesired drop dispersion, is then selected for use during the next print mode. The optimum waveform is characterized by a single maxima and minima separated in phase by a value no greater than a predetermined maximum value. | 1 |
This invention relates generally to a apparatus for enhancing pixel addressability in a digital imaging system, and more particularly to a digital pulse width and position modulator, which generates complimentary video pulses.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention is intended for use in a scanning output system that uses a beam for generating information, or more specifically, wherever a digital pulse forming circuit may be used to control a scanning beam. The beam may vary in intensity and duration according to the pulses used to control the beam. For example, a laser beam may be used in a printer for selectively exposing areas on a photoreceptor. The latent electrostatic image formed on the photoreceptor by the beam exposure attracts developing toner in proportion to the latent image charge level to develop the image. As another example, a cathode ray tube uses an electron beam to scan a phosphorous screen. The electron beam may be varied in intensity and duration to accurately display information on the phosphorous screen. In both examples, a pulse forming circuit may be used to generate video pulses to control the intensity and operation time of the respective beams.
Heretofore, various methods and apparatus have been used to vary the position and width of pulses used to control laser or CRT beams. The following disclosures may be relevant:
U.S. Pat. No. 4,347,523, also to Ohara, discloses an apparatus of general interest which uses an input signal to address pulse numbers with corresponding pulse width selection numbers.
U.S. Pat. No. 4,375,065 to Ohara describes an apparatus of general interest that uses pulse number and pulse position modulation to control a laser beam.
U.S. Pat. No. 4,390,882 to Ohara et al. discloses for an image processing apparatus a method of adjusting the image density by controlling the on time of the laser. Control of the laser on time is performed by a multivibrator having a variable RC time constant.
U.S. Pat. No. 4,544,264 and U.S. Pat. No. 4,625,222, both issued to Bassetti et al. describe enhancement circuits suitable for use in a laser based electrophotographic printing machine. The enhancements are directed at modifying the digital drive signals used to produce the image, including smoothing digitized edges and broadening fine lines in both the horizontal and vertical directions. Leading and trailing edge signals, in both directions are provided to potentially print each black pixel or line as a series of three pixels, a gray leading pixel, overlapped by a central black pixel, which is in turn overlapped by a gray trailing pixel. A similar process is applied for scanlines as well. The series of signals are recombined to effectively control the voltage and current levels of a laser driver.
U.S. Pat. No. 4,544,922 to Watanabe et al. teaches a smoothing circuit for an orthogonal matrix display. The circuit adds or removes a "small dot" on the display from either the first or last third of a dot clock (DCK) period which is one-third the period in which a standard dot of the original pattern is displayed.
U.S. Pat. No. 4,626,923 to Yoshida teaches an image processing apparatus for producing a halftone image in which the on time of the laser is controlled by both the image input data and a pulse width modulation circuit. The image data is transferred under control of clock signal, CLK. The pulse width modulation circuit includes a clock, CLKH, having a frequency three times that of CLK, which is used together with latches and AND gates to provide synchronous sub-pixel addressing.
U.S. Pat. No. 4,661,859 to Mailloux et al. describes an image processing circuit for producing a greyscale image in which the on time of the laser is controlled by both the video input data and the pulse width modulation circuit. The pulse width modulation circuit includes a clock having a frequency greater than the video data rate, which allows synchronous sub-pixel addressing.
U.S. Pat. No. 4,905,023 to Suzuki, describes an image forming apparatus using a plurality of conversion tables addressed by an input video image signal to generate pulses.
U.S. Pat. No. 4,926,268 to Kawamura et al. discloses an image processing apparatus which employs analog circuitry to produce a pulse-width modulated (PWM) output from a multi-level digital signal. As described, each analog signal is generated in synchronism with the pixel clocks.
U.S. Pat. No. 4,933,689 to Yoknis describes a method for enhancing a displayed image in a laser exposed dot matrix format to produce softened edge contours. Using three pulses, a central pulse plus leading and trailing enhancement pulses which are separated therefrom. The purpose of the leading and trailing pulses is to create a blurred or grayed region at the leading and trailing edges of each associated character.
U.S. Pat. No. 4,965,672 to Duke et al. discloses an apparatus for varying the width and position of pulses used to control a laser beam.
U.S. Pat. No. 5,144,337 to Imamura et al. teaches an image forming apparatus suitable for changing the size of an output dot in a main and subscanning direction. Dot size and shape are controlled by pulse width modulation and power modulation applied to a laser diode.
U.S. Pat. No. 5,144,338 to Sakano discloses an image recorder which employs a pulse width modulated laser beam to control the recording position on a photoconductive drum. The position (left aligned, centered, or right aligned) and duration (12 ns, 20 ns, 32 ns, or 56 ns) of the pulse within a pixel interval is determined based upon the tone level of the pixel of interest and its relation to the tone levels of both preceding and following pixels.
U.S. Pat. No. 5,184,226 to Cianciosi describes a digital system for generating pulses from a series of data words, the relevant portions of which are hereby incorporated by reference. The system employs multiple RAM look-up tables for translating the data words into a series of corresponding pulses utilizing two channels to achieve the desired throughput.
U.S. Pat. No. 5,193,011 to Dir et al. discloses a system for printing gray levels without the need of a halftone cell. The system determines the pulse width for each pixel as a function of the gray level of the pixel, based upon an iterative comparison to an incrementing grey level clock. In one embodiment, a page-wide liquid crystal shutter is used to regulate the exposure of a photoconductive drum. The shutter may be toggled on and off multiple times for each pixel during the recording of a single row of the image.
L. Steidel in "Technology Overview: Resolution Enhancement Technologies for Laser Printers", LaserMaster Corp., discusses three currently available implementations for vertical resolution enhancement, Resolution Enhancement Technology, Paired Scan Line Scheme, and TurboRes. In all cases, the horizontal resolution of the laser scanner is increased by increasing the clock speed. On the other hand, the vertical resolution is enhanced by combining the weaker laser laser energy from a brief laser flash, which leaves only residual or fringe energy on the image drum at the periphery of a pixel of an adjacent pixel on a second scan line.
An object of the present invention is to provide a pulse width position modulation system having the capability to selectively produce multiple pulses within a predefined pixel clock period without the necessity of increasing the speed of the hardware used to produce the pulses.
Another object of the present invention is to enable the pulse width position modulation system to selectively produce pulses which are justified with the beginning and end of a predefined pixel clock period so as to enable the extension of adjacent pulses produced in preceding or succeeding clock periods.
In accordance with the present invention, there is provided an apparatus for generating multiple pulses within a predefined clock period. The apparatus comprises means for specifying the leading edge delay for a first pulse to be generated during the predefined clock period, means for specifying the trailing edge delay for the first pulse to be generated during the predefined clock period, means for generating the first pulse during the portion of the clock period between the leading edge delay and the trailing edge delay, and means, selectable on a clock period basis, for inverting the first pulse to produce a pair of complimentary pulses within the selected clock period.
In accordance with another aspect of the present invention, there is provided a digital electronics system capable of generating pulses within predefined clock periods which delimit pixel boundaries. The system includes an apparatus for extending the pulses beyond the pixel boundaries, comprising, means for specifying the leading edge delay for a first pulse to be generated during the predetermined clock period, means for specifying the trailing edge delay for the first pulse to be generated during the predetermined clock period, means for generating the first pulse during the portion of the clock period between the leading edge delay and the trailing edge delay, and means, selectable on a clock period basis, for inverting the first pulse to produce a pair of complimentary, boundary justified pulses within the selected clock period, said boundary justified pulses thereby extending the pulses generated during a preceding and a succeeding clock period.
In accordance with yet another aspect of the present invention, there is provided a digital electronics system for generating pulses from a series of data words, comprising means for translating the series of data words into a series of pulse attribute words, wherein each pulse attribute word includes information for controlling the formation of a corresponding pulse during a clock period, means for splitting the series of pulse attribute words into two channels, means corresponding to each channel for accepting pulse attribute words from respective channels, and forming pulses using the information included in the pulse attribute words for controlling the formation of the pulses, means for generating the pulses, wherein a pulse from a first pulse forming means is generated while a pulse from a second pulse forming means is being formed, and means for inverting the pulse generated during a selected clock period to produce a pair of complimentary pulses within the selected period.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a Raster Output Scanner (ROS), illustrating a portion of the photosensitive image plane;
FIG. 2A is a schematic illustration showing an example of a pulse with variable width and position;
FIGS. 2B is a schematic illustration of the complimentary pulses produced using the pulse of FIG. 2A in accordance with an embodiment of the present invention;
FIG. 3A is a schematic illustration showing an example of a pulse with variable width and position;
FIGS. 3B is a schematic illustration of the complimentary pulses produced using the pulse of FIG. 3A in accordance with an embodiment of the present invention;
FIGS. 4 and 5 are a schematic block diagram of a pulse modulator according to an embodiment of the present invention;
FIG. 6 is a schematic diagram illustrating the detail of the video pulse inversion and combination logic blocks depicted in FIG. 5; and
FIGS. 7 through 9 illustrate timing diagrams for the various signals used in the video pulse inversion and combination logic blocks depicted in detail in FIG. 6.
The present invention will be described in connection with a preferred embodiment, however, it will be understood that there is no intent to limit the invention to the embodiment described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For a general understanding of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements. FIG. 1 shows a raster output scanner (ROS) which may be used to print video signals produced by a source (not shown). There are two common types of ROS 18, flying spot and pulse imaging ROSs. In both, a laser beam 20, emitted from laser 22, passes into conditioning optics 24 which includes a modulator 25. For precise periods of time, determined in response to video signals supplied to ROS 18, modulator 25 either blocks or deflects the laser beam, or allows to the beam to pass through the conditioning optics to illuminate a facet 26 of rotating polygon 28. Laser 22 may be a helium-neon laser or a laser diode. In the latter case, the video data would directly modulate the laser rather than modulator 25. In addition, more than a single laser source 22 or beam 20 could be employed to practice the invention.
After reflecting off facet 26, laser beam 20 passes through conditioning optics 30 and forms a spot 21 on photosensitive image plane 32. The rotating facet causes laser spot 21 to scan across the image plane in a line 34. Line 34 lies in what is commonly referred to as the fast scan direction, represented by arrow 36. In addition, as facet 26 rotates, image plane 32 moves in a slow scan direction, substantially perpendicular to the fast scan direction, as represented by arrow 38. Movement in the slow scan direction is such that successive rotating facets of the polygon for successive scanlines 34 that are offset from each other in the slow scan direction.
Each scan line 34 consists of a row of pixels 40, wherein the pixels are produced by the modulation of the laser beam as laser spot 21 scans across the image plane. As beam 20 scans across the scanline, pixel spot 21 either illuminates or does not illuminate the individual pixel, in accordance with the video signals provided to ROS. In general, the video signals may be characterized as a serial stream of binary pulses, where a logic one or a pulse specifies that the beam is to illuminate the surface, while a logic zero, no pulse, will result in no illumination.
For both types of ROS, the width of pixel 40 is dependent upon the period or duration of the corresponding logic one pulse in the video signal supplied to ROS 18. In a scanning spot ROS, at the leading edge of a pulse, for example edge 50 of FIG. 2A, modulator 25 allows the passage of laser beam 20 onto the image plane. For the duration of the pulse, and oval shaped laser spot 21 is scanned across image plane 32, illuminating at least one addressed pixel 40 within the scan line 34. The width of the illuminated region in the fast scan direction thus depends on the duration of the video pulse, as well as on the width and scanning rate of laser spot 21. Typically, the dimensions of the laser spot are such that it is two to three times taller in the slow scan direction than its width in the fast scan direction. As an example, in a 600 spi, 135 ppm, dual beam printer, the laser spot is approximately 43 μm high and 20 μm wide, and the time period required for the spot to scan across the width of a single pixel 40 is about 15 nanoseconds.
Typically, the video data used to drive the ROS is clocked so that the period within which each pixel is exposed, referred to hereafter as a pixel clock period, is the same. In addition, the video data used to generate the video signal pulses which drive the modulator are also synchronized with ROS 18 and the movement of the image plane 32 in the slow scan direction, thereby allowing a particular bit of video data to address an appropriate portion of image plane 32. The synchronization of the video data, the video signal pulses produced therefrom, the ROS and the image plane is achieved through the use of a system clock that is equivalent to the rate at which pixels must be exposed on the image plane. While faster clocks may allow greater resolution within the video pulse stream, a higher frequency also results in increased costs for faster hardware within the video processing path.
In the present embodiment, a pulse width, position, and amplitude modulator (pulse modulator) is utilized to form the video signal pulses in response to video data representing the image to be printed. Referring to FIGS. 2A through 5, it should be noted that while the following description of the pulse modulator is directed toward a single color output, there is no intent to limit the application of the present invention in such a manner.
FIGS. 2A and 3A show the general organization for pulse formation of the pulse modulator. Moreover, FIGS. 2A and 3A show exemplary pulse characteristics for first or primary video pulse signals generated by the invention. As shown by the two pulses represented in the figures, the width and position of a pulse 52 within a pixel clock period 54 may be varied with separate, independently variable delays for the leading edge 56 and trailing edge 58 of the pulse 52. A leading edge delay 56 is defined from the beginning of a pixel period 60 to the leading edge of the pulse 50. A trailing edge delay 58 is defined from the beginning of a pixel period 60 to the trailing edge of the pulse 62. In a normal operating mode, pulse 52 would be generated in response to information in a corresponding data word, as disclosed in U.S. Pat. No. 5,184,226 to Cianciosi, issued Feb. 2, 1993, the relevant portions of which are hereby incorporated by reference.
Generally, each pulse 52 is formed according to the information in a corresponding data word. A series of data words is input into a pulse modulator (not shown), and each data word is consecutively translated into a set of pulse attribute words. Each pulse attribute word corresponds to a characteristic of a corresponding pulse to be formed by the pulse modulator. Thus, each data word contains the information for forming a pulse.
The architecture of the pulse modulator will now be described with reference to FIG. 4. A series of data words, each n bits per pixel where n is 8 in the preferred embodiment, is input into the pulse modulator from a video or image source 101, such as a computer memory or an image scanner. The series of data words may be sent through a video expansion port 103 to other pulse modulators (not shown) for parallel processing, such as in the case of color printing where similar processing of the video information is performed for different colors.
The present invention further includes translating means, splitting means, pulse forming means, and generating means. In the pulse modulator of FIG. 4, a data word from the series is sent through a RAM address multiplexer 105 to a translating means. As embodied herein, the translating means comprises four RAM lookup tables 107, 109, 111, and 113. Each data word represents an address within the four RAM lookup tables 107, 109, 111, and 113. In a preferred embodiment, a pair of 256×4 ECL RAM lookup tables is used to generate a pulse attribute word for each pulse attribute sought to be controlled.
Pulse attributes may include leading edge delay, trailing edge delay, amplitude of the pulse to be formed, and other special features such as an inverted or multiple pulse per pixel selection, as will be described with respect to the present invention. Alternatively, a single 256×8 ECL RAM lookup table may be used to generate each pulse attribute word. The embodiment of FIG. 4 shows two pairs of 256×4 RAM lookup tables 107 and 109, 111 and 113 which correspond to the two pulse attributes of leading edge delay and trailing edge delay. The pulse modulator will accommodate as many pairs of 256×4 RAM lookup tables as there are desired pulse attributes. For example, a third pair of 256×4 RAM lookup tables may be used to control the amplitude of a pulse to be formed. Alternatively, a series of RAM addresses in the lookup tables may be assigned to produce inverted pulses. For example, addresses 64-127 would be decoded so that the pulses produced in response to the data output from those table locations would be inverted. Furthermore, a larger or smaller number of addresses may be used, or allocated, for the production of inverted pulses.
Once an address in each RAM lookup table is accessed by the data word, each RAM lookup table generates a nibble (4 bits) of information. Thus, each pair of RAM lookup tables generates a pulse attribute word (8 bits) corresponding to the pulse attribute sought to be controlled. While an 8-bit implementation may be preferable, it is not a limitation, and the pulse attribute word may be any number of bits (i.e., 4, 6, 8, 10, 12, etc.).
Characteristic data indicative of the pulse attributes sought to be controlled in a pulse modulator may be downloaded into the RAM lookup tables 107, 109, 111, and 113 from the lookup table download interface 115. Once the lookup table download interface 115 accesses an address of a RAM lookup table, a pulse attribute data nibble may be loaded into the RAM lookup table through the lookup table data bus 117 from the lookup table download interface 115. This allows for different mapping functions in the same pulse modulator for different printing characteristics (i.e., font smoothing, graphics, etc.), and further facilitates maintenance of print quality as the components of the system age. After the RAM lookup tables 107, 109, 111, and 113 are loaded, the lookup table download interface 115 instructs the RAM address multiplexer 105 to receive data from the video data bus 119.
In the embodiment of FIG. 4, the four RAM lookup tables 107, 109, 111, and 113 perform a logic mapping function, which translates the incoming data word into two pulse attribute words to control the formation of a pulse. In FIG. 4, the top two RAM lookup tables 107 and 109 generate separate nibbles of pulse attribute information which combine to form a pulse attribute word for the leading edge delay of a pulse to be formed. The bottom two RAM lookup tables 111 and 113 generate separate nibbles of pulse attribute information which combine to form a pulse attribute word for the trailing edge delay of a pulse to be formed.
Each pulse attribute word is fed to a respective splitting means which comprises multiplexer and latch blocks 121 and 123. In the preferred embodiment, each respective multiplexer and latch block contains two latches, one for each of the phase 1 and phase 2 buses. The two pulse attribute words generated in the RAM lookup tables 107, 109, 111, and 113 from a data word are latched onto the phase 1 buses by their respective multiplexers 121 and 123 at a leading edge of a pulse from the phase 1 video clock 135.
The two data words latched on their respective phase 1 buses 125 and 127 are further processed on separate channels in a pulse forming means corresponding to each channel. As depicted, the pulse forming means comprises a delay logic block 129 for forming separate leading and trailing edge delayed pulses and a video pulse forming logic block 131. The video pulse forming logic block 131, which comprises the generating means, forms a single pulse from the leading and trailing edge delay pulses. Subsequent to generation of the first or normal pulse in the video pulse forming logic block 131, the pulse may be inverted under the control of the combination logic block 149.
As represented by the preferred embodiment depicted in FIG. 5, combination logic block 149 may be an XOR gate. Video combination logic block 149 allows the video signal from video pulse forming logic block 131 to pass unaltered if a logic zero is present on the inversion control line. On the other hand, at any time the video pulse inversion logic block 145 should produce a logic one on the inversion control line, the video pulse signal output from block 131 will be inverted so as to form a pair of video pulses.
It is noted that the speed of a typical scanning system, with only a single phase video clock and corresponding phased set of busses, is limited by the speed at which its delay and pulse forming logic 129 and 131 can operate on pulse attribute words and then be reset to accept new pulse attribute words. In the embodiment shown in FIG. 4, with only the phase 1 video clock 135 and phase 1 busses 125 and 127, the delay and pulse forming logic blocks 129 and 131 may limit the processing speed of the pulse modulator. Specifically, while the two pulse attribute words corresponding to the first data word are being processed by the delay and pulse forming logic blocks 129 and 131, a second pair of pulse attribute words corresponding to a second data word will already be formed, waiting at the respective multiplexer and latch blocks 121 and 123 to be latched onto the phase 1 busses 125 and 127 and processed by the delay and pulse forming logic 129 and 131.
Referring once again to FIGS. 2A, B and 3A, B, where the representative signals are illustrated, FIGS. 2A and 3A are intended to represent the first or normal video signal pulse output from video pulse forming logic block 131. As previously described pulses 52 have a position and width defined by the leading and trailing edge delays stored in the RAM lookup tables. Although FIGS. 2A and 2B, depict pulses 52 which lie entirely within clock period 54, the pulses could also extend so as to be justified with a boundary of the clock period. Furthermore, the same "normal" video pulses may also be used to produce one or two complimentary or inverted pulses, 70 and 72, justified to the respective pixel clock boundaries, 60 and 61 as depicted in FIGS. 2B and 3B. Because they are defined over the same pixel period 54, the characteristics of complimentary pulses 70 and 72 are also directly controllable by the previously described pulse attribute words.
Referring also to FIG. 6, along with timing diagrams of FIGS. 7-9, where the details of the video inverting means are illustrated, it can be seen that inversion logic block 145 is designed to correctly synchronize the timing of the inversion control signal on line 210 with the video pulse signal output by video pulse forming logic block 131. More specifically, it is necessary to assure that the selection signal provided on inversion control line 210 be produced in synchronization with the video signal in order to assure accurate control of the video output signal on pixel boundaries. As illustrated, the video pulse inversion logic block 145 is comprised of pulse decoding block 212, a pair of pulse skew adjusting blocks, 214 and 216, and a corresponding pair of inverting blocks, 218 and 220. Pulse decoding block 212 is intended to detect and decode the video data signals from the RAM Address Bus in order to determine which pulses are to be selectively inverted to produce desired complimentary pulses. More specifically, the necessary synchronization is achieved using the A LATCH CLOCK and B LATCH CLOCK signals, input to block 212, to initiate the timing delay within the inversion logic block. The DECODE 1 and DECODE2 signals are used to enable the inversion block. In one embodiment, the two most-significant bits (A 6 and A 7 ) of the 8-bit video address being input to the ROM lookup tables may be used for DECODE 1 and DECODE2. Thus, whenever the upper 128 addresses of the lookup table are accessed, the inversion block will be enabled. Subsequently the A and B phase pulses are routed through skew adjusting blocks 214 and 216 (e.g., programmable delay circuits) in order to compensate for timing skew, such as gate delays, between the inverted and non-inverted pulse paths. Skew adjusting blocks 214 and 216 both adjust for any timing skew between the pulse width position modulated channels (A and B) in the present embodiment. Programmable hex switches are used to establish the delays (D1 and D2 in FIGS. 8 and 9) with delay devices 215 and 217. Both skew adjusting blocks include circuitry to align the inverted video output pulse in an appropriate spatial relationship with the non-inverted video output pulse. More specifically, the rising edge of the inverted pulse is aligned with the edge of a non-inverted pulse having a programmed delay of zero. Lastly, inverting blocks 218 and 220 capture the decoded pulse signals and skew adjustment signals produced by blocks 214 and 216, respectively, to produce a skew adjusted, inversion control signal which may be combined with the video pulses at combination logic block 149 to selectively produce the complimentary dual pulse video output.
In recapitulation, the present invention is an apparatus for improving the addressability of a system employing a pulse width and position modulated signal. The invention enables the selective generation of video signals having pulses which extend beyond clocked pixel boundaries. A pair of pixel clock boundary justified pulses are produced by generating the compliment to a normal pulse width and position modulated video pulse.
It is, therefore, apparent that there has been provided, in accordance with the present invention, an apparatus for enhancing pixel addressability in a digital output device. While this invention has been described in conjunction with preferred 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. | The present invention is a digital electronics system for generating multiple pulses within a predefined pixel clock period in a digital output device, where both a leading edge delay and a trailing edge delay are specified for a first pulse to be generated during the predetermined clock period. Pulse forming circuitry generates the first pulse during the portion of the clock period between the leading edge delay and the trailing edge delay, and an inverting circuit, selectable on a clock period basis, is activated to produce complimentary pulses within the selected clock period. The system is depicted as a two phase embodiment which enables high-speed operation. | 7 |
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