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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of PCT application Ser. No. PCT/EP02/12887, filed Nov. 18, 2002, which claims priority to German Patent Application No. 102 10 351.8, filed on Mar. 8, 2002, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
This invention relates to a cleaning device of a dry shaving apparatus, with a base plate and a chassis arranged for displacement relative to the base plate, and a spring adapted to be secured therebetween.
BACKGROUND
A cleaning device of this type is known from the appliance of the Braun company sold under the name “Clean & Charge”. This cleaning device includes a housing into which the dry shaving apparatus is inserted for cleaning purposes. This involves receiving the shaving head of the shaving apparatus in a receptacle designed as a cleaning bath. The housing further accommodates a reservoir containing a cleaning fluid. To clean the shaving head the cleaning fluid is fed from this reservoir into the receptacle. In the receptacle the cleaning fluid is caused to contact the shaving head in order to remove the hair dust collected in the shaving head. From the receptacle the cleaning fluid flows back into the reservoir, entraining with it the removed hair dust. The principle of operation of such a cleaning device is known, for example, from DE 44 02 237 C2. Considering that the effect of the cleaning fluid weakens with the number of cleaning processes increasing, it is necessary to substitute fresh cleaning fluid after a certain number of cleaning cycles. For this reason, the reservoir for the cleaning fluid is of the replaceable type. To replace the cleaning fluid reservoir, the housing of the cleaning device is opened by means of a lift mechanism, enabling the previous reservoir to be removed and a reservoir containing fresh cleaning fluid to be substituted. For this purpose, the cleaning device is divided into a base plate and a chassis.
The chassis is comprised of a chassis plate and the chassis proper. The base plate has guides for the spiral springs, said spiral springs being biased towards the chassis plate with the cleaning device in closed condition. Through a button provided on the outside of the housing the locked relationship between chassis and base plate is canceled and the lift mechanism is activated. The three spiral springs are untensioned and lift the chassis, thereby releasing the cleaning fluid reservoir for replacement. After the reservoir is replaced, the chassis is pushed down against the base plate, locking onto it at the same time. With the downward movement of the chassis the spiral springs are tensioned. Owing to the long opening travel of the housing it is necessary for the spiral springs to have a long spring excursion. At the same time the spiral springs have to hold the chassis securely in open condition. This necessitates relatively high forces for closing the housing and simultaneously tensioning the spiral springs. Moreover, these forces have a particularly strong effect also in closed condition because the spiral springs have a progressive spring characteristic. This puts a considerable strain on the structure of the cleaning device. Furthermore, the abrupt beginning and the abrupt end of the opening movement at a stop is accompanied by loud noise. On account of the long spring excursion the spiral springs are guided. On actuation of the lift mechanism the spiral springs come into contact with the guides, which likewise leads to a not insubstantial noise level.
It is therefore an object of the present invention to provide a cleaning device with a lift mechanism that operates as smoothly as possible, develops minimum possible noise while being of straight-forward construction, and puts little strain on the structure of the cleaning device.
SUMMARY
According to the present invention this object is accomplished by providing the lift mechanism with at least one coiled-strip spring. The chassis is spring-loaded against the base plate by the coiled-strip spring. With the cleaning device in closed condition, the coiled-strip spring is uncoiled. Actuation of the lift mechanism releases the chassis, which is then moved by the relaxing coiled-strip spring coiling up in the process. An advantage of a coiled-strip spring made of strip steel is its nearly linear spring characteristic and its almost noiseless operation. In addition, owing to the coiling motion impact-type contact with other components or with itself is prevented from occurring during both coiling up and uncoiling, but rather, the chassis is lifted at a relativity constant speed through the entire stroke travel. The coiled-strip spring hence can enable a substantially quieter lift mechanism. Moreover, the coiled-strip spring can reduce the load on the chassis so that the construction has to withstand less severe stresses, strains and loads. The provision of a suitable arrangement can render the coiled-strip spring, which coils up when the cleaning device is opened, invisible to the user. Therefore an additional surface treatment or encapsulation of the coiled-strip spring to enhance its appearance can be avoided.
Preferably, the base plate has at least one guide that supports the movement of the chassis. Apart from one guide disposed centrally on the base plate, the arrangement of several guides on the circumference of the base plate may also be considered. Arranging the guides on the circumference has the advantage that sufficient space is available in the center of the base plate for the cleaning fluid reservoir and other built-in components. Canting of the chassis plate is avoided if guide bushings having a long guide length are provided on the chassis.
This guide may be constructed at the same time as a guide for one or several coiled-strip springs. The use of two coiled-strip springs for each guide, referred to as twin coiled-strip springs, is advantageous in this connection. The arrangement of two coiled-strip springs allows the use of small springs, and also enables the symmetrical arrangement of the coiled-strip springs on a guide, which largely eliminates the risk of canting the chassis during the opening movement.
It is suitable to design two coiled-strip springs (twin coiled-strip springs) as a one-piece construction. In this design each end of a U-shaped length of strip steel is formed as a coiled-strip spring, with the two springs coiling up or uncoiling in outward direction. This enables both coiled-strip springs to be arranged on the guide with a single fastening. As a result, the number of single parts is reduced while at the same time the assembly is simplified. The coiled-strip springs may be fastened to the guide by frictional as well as positive engagement using, for example, screws, clips or rivets.
In another aspect the lift mechanism includes elements that slow down the movement of the chassis during opening of the cleaning device until the end position is reached. This can result in a noiseless opening movement, since the chassis is prevented from striking hard against a stop limiting the opening movement. Furthermore, decelerating the lift mechanism has a wear-reducing effect.
The elements for the decelerated lift mechanism can be elastic elements arranged either on the guide, the base plate or the chassis. The elastic elements may be spring, rubber, foam or other plastic parts which are moved against a stop. In this context, springs are advantageous because they allow slowing down of the lift mechanism through a relatively long travel. The stop may be arranged on the chassis as well as on the guides, preferably at the end remote from the base plate. Ease of assembly is accomplished by fastening the stop or the spring to the guide together with the coiled-strip spring. The use of spring clips is particularly suitable in this connection. These clips enable the fastening of the coiled-strip springs in addition to providing one or several springs for slowing down the opening movement of the chassis plate just before reaching the end position.
In another embodiment with the spring clips, the springs are bending springs cooperating each with a ramp disposed on the chassis. By suitably selecting the incline of the ramp a wide variety of different deceleration characteristics can be set. Thus a minor incline of the ramp results in a slow deceleration of the opening movement, while a major incline of the ramp produces a rapid deceleration. By varying the inclination over the distance to be covered it is possible to obtain combinations of the two decelerations. Thus it can be considered to provide the ramp initially with a small incline, which results in only a slow deceleration of the opening movement. As the chassis plate continues its approach to the end position, the ramp's incline increases, leading to a progressively increasing deceleration of the opening movement up to a complete stop. With suitable selection of the ramp design it is thus possible to set the end position in a defined manner. In this instance no additional stop for the lift mechanism is necessary.
Further objects, features, advantages and application possibilities of the present invention will become apparent from the subsequent description of the embodiments. It will be understood that any single feature or any combination of single features described or represented by illustration form the subject-matter of the present invention, irrespective of their summary in the claims or their back-references.
BRIEF DESCRIPTION OF DRAWINGS
An embodiment of the present invention will be described in the following. In the drawing,
FIG. 1 is a schematic view of a cleaning device;
FIG. 2 is an exploded view of the lift mechanism of the cleaning device;
FIG. 3 is a perspective view of the lift mechanism in retracted condition;
FIG. 4 is a side view of the lift mechanism in open condition; and
FIG. 5 is a side view of the guide of FIG. 4 .
DETAILED DESCRIPTION
The cleaning device 1 shown in FIG. 1 is comprised of a base plate 2 and a chassis 3 . The chassis 3 is composed of two housing parts 4 , 5 . The shaving head of a dry shaving apparatus, not shown, is insertable into an opening 6 . Arranged underneath the chassis 3 are the devices needed for cleaning the dry shaving apparatus, such as the reservoir and the pump for the cleaning fluid and the lift mechanism.
The lift mechanism shown in greater detail in FIG. 2 comprises the base plate 2 from which three guides 7 a - c extend in upward direction. Slidably arranged along the guides 7 a - c is a chassis plate 8 . To avoid canting of the chassis plate 8 , the chassis plate 8 includes three guide bushings 9 . The chassis plate 8 mounts the housing parts 4 , 5 of the chassis 3 . Arranged on each of the guides 7 a , 7 c are two coiled-strip springs 10 a - d which are able to coil up and uncoil along a guideway 11 . Each pair of coiled-strip springs 10 a, b; 10 c, d, bent in a U-shaped configuration, are integrally connected with each other and fastened to the upper end of the respective guide 7 a , 7 c together with a respective spring clip 12 by two screws 15 . The spring clips 12 have two laterally arranged cantilevered portions 13 with inwardly bent tongues 14 supporting each other. For this purpose the guides 7 a, 7 c have a respective recess 26 at the appropriate level. The tongues 14 may also be supported by corresponding surfaces of the guides 7 a, 7 c. Arranged on the base plate 2 on a bridge are two detent hooks 16 which cooperate with a detent slide 17 to lock the chassis 3 onto the base plate 8 when the lift mechanism is in a retracted condition. The detent slide 17 has several detent bars 18 for engagement with the detent hooks 16 . To connect the detent slide 17 to the chassis plate 8 , hooks 20 are provided on the chassis plate's upper side. Shaped elements 21 disposed between the hooks 20 provide a guide for the detent slide 17 . A return spring 22 ( FIG. 3 ), likewise secured to the chassis plate 8 , effects movement of the detent slide 17 into a predetermined initial position.
FIG. 3 shows the chassis plate 8 in its retracted condition in which it is locked onto the base plate 2 . In this condition the detent bars 18 engage behind the detent hooks 16 . Together with the spring clips 12 the coiled-strip springs 10 are snap-locked on the guides 7 a, 7 c or secured thereto by screws. With the chassis plate 8 locked in place, the coiled-strip springs 10 are tensioned due to uncoiling. The ends of the coiled-strip springs 10 are arranged within the guide bushings 9 . Operation of the actuating element 23 causes the detent slide 17 to be displaced along the shaped elements 21 in opposition to the return spring 22 . As this displacement occurs, the detent bars 18 are no longer in engagement with the detent hooks 16 , and the lift mechanism operates to cause the chassis plate 8 to be moved upwards along the guides 7 a - c. After the actuating element 23 is released, the detent slide 17 is moved back to its initial position by the return spring 22 . The upward movement of the chassis plate 8 is effected by the coiled-strip springs 10 . The cleaning device 1 is thus open. To close the cleaning device 1 , the chassis 3 and chassis plate 8 are together moved downwards manually. During the downward movement of the chassis plate 8 the detent bars 18 of the detent slide 17 engage the detent hooks 16 . Lateral chamfers 19 on the upper side of the detent hooks 16 effect displacement of the detent slide 17 against the return spring 22 as the chassis plate 8 continues its downward movement. Once the chassis plate 8 is displaced downwards such a distance that the detent bars 18 are underneath the detent hooks 16 , the return spring 22 moves the detent slide 17 back into its initial position whereby the detent bars 18 engage behind the detent hooks 16 . The chassis plate 8 is thus again locked onto the base plate 2 , and the cleaning device 1 is closed. The audible locking action as the result of return spring 22 causing the detent bars 18 to strike against the detent hooks 16 is at the same time an audible signal informing the user of the cleaning device 1 that the lift mechanism is locked in place and the cleaning device closed.
The open cleaning device 1 is shown in FIG. 4 . Guide bushings 9 formed on the chassis plate 8 receive the guides 7 of the base plate 2 . By means of suitable snap-locks and/or screws 15 , a spring clip 12 and the coiled-strip springs 10 c, 10 d are fastened to the guide 7 c. The two coiled-strip springs 10 c, 10 d are bent in a U-shaped configuration and embrace the guide 7 c . The coiled up ends of the coiled-strip springs 10 c, 10 d rest each against a respective stop 24 of the guide bushing 9 , thus spring-loading the chassis plate 8 against the base plate 2 . In the end position shown, the coiled-strip springs 10 are not completely untensioned, but possess sufficient bias to reliably hold the chassis plate 8 in the end position. The guide bushing has two masking plates 25 arranged in front of the coiled up ends of the coiled-strip springs 10 . These masking plates 25 protect the coiled-strip springs in addition to providing a sightproof guard so that that the coiled-strip springs 10 are not visible to the user when the cleaning device 1 is open. For closing the cleaning device 1 , the coiled up ends of the coiled-strip springs 10 are urged downwardly by the stops 24 , causing the ends to uncoil. The coiled-strip springs 10 are thereby tensioned. The coiled-strip springs 10 are constructed in such a way that the ends are coiled up in closed condition, that is, as shown in FIG. 3 , in order to ensure reliable contact with the stops 24 . On actuation of the lift mechanism the guide bushings 9 slide with sliding surfaces 30 against the coiled-strip springs 10 .
FIG. 5 is a sectional view of the guide in its closed condition. In this view the chassis plate 8 is locked onto the base plate 2 . The spring clip 12 connected with the guide 7 c has two lateral cantilevered portions 13 with inwardly bent ends 14 which extend into the recess 26 in the guide 7 c. Arranged in the guide bushing 9 is a ramp 27 . The ramp 27 is arranged in such a manner that its distance to the guide 7 c is progressively reduced from top to bottom. Opposite the ramp 27 , the guide bushing 9 has a limit stop 28 extending parallel to the guide 7 c. At the lower end the limit stop 28 has an inwardly extending shoulder 29 . The attenuation of the lift mechanism just before reaching the end position will be described below.
As the chassis plate 8 is moved upwards, the ramp 27 strikes the cantilevered portion 13 . In continuation of this movement, the cantilevered portion 13 is bent inwardly. The end 14 is also deflected inwardly until it meets the opposite end 14 , urging it against the limit stop 28 of the guide bushing 9 . On account of this elastic deformation of the spring clip 12 the upward movement of the lift mechanism is slowed down. With an appropriate design of the ramp and the spring clip 12 deceleration of the lift mechanism and the end position of the chassis plate 8 can be set arbitrarily within wide limits. Thus, it can be considered to design the limit stop 28 likewise as a ramp. In the present case the end position is produced by positive engagement when the shoulder 29 formed in the guide 9 meets the right-hand cantilevered portion 13 of the spring clip 12 .
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A lift mechanism for a cleaning device of a dry shaving apparatus includes a base plate with guides and a chassis plate mounting the chassis and arranged for displacement relative to the base plate. Coiled-strip springs arranged on the guides spring-load the chassis plate against the base plate. On actuation of the lift mechanism the coiled-strip springs are untensioned by coiling up along the guides, thereby lifting the chassis plate. The coiled-strip springs reduce the load on the construction and ensure an almost noiseless lift mechanism.
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INTRODUCTION AND BACKGROUND
The invention relates to a device for monitoring a melt for the production of crystals and a process therefor.
When a given material, for example, Si polymaterial is thoroughly melted in a quartz crucible, the transition from a solid to a liquid state does not, as a rule, occur abruptly, but rather, gradually. In the actual practice of creating crystals it is very important that the given melt state be precisely known or identifiable, since this state dictates the procedural steps that are to follow.
There are experienced melt specialists who are able to precisely infer the state of the melt from the surface appearance of a crucible. Also known is the automatic identification of a melt state using pyrometers as sensors, though this results in an unreliable kind of regulation involving long time constants.
Various processes have already been suggested for an improved automatic regulation of the drawing process of a monocrystal. For example, a process for drawing a monocrystal from the melt is known in which the individual crystals are drawn up while the data influencing the drawing process, which are based on numerous conditions, are recorded and compared with other data (EP 0 536 405 A1). In the process, a laser beam, for example, strikes the surface of molten material located in a crucible. Identification of a reflected laser beam allows the position of the molten surface to be determined, and the crucible is elevated according to the difference between the measured position and a predetermined position. However, this known process does not permit reliable process monitoring during the melting phase.
Also known is an optical system or process for regulating the growth of a silicon crystal in which the diameter of a silicon crystal drawn from a melt is measured with the assistance of a television camera; here the surface of the melt exhibits a meniscus which is visible as a bright area in close proximity to the silicon crystal (EP 0 745 830 A2). In this system, a camera is used to produce an image pattern of a portion of the bright area near the silicon crystal. The characteristics of the image pattern are then detected. A characteristic of the visual pattern would be, for example, the light intensity gradient. After this, one edge of the bright area is defined as a function of the detected characteristics. Then an outline is defined which closes the defined edge of the bright area; finally the diameter of the defined outline is determined, and the diameter of the silicon crystal is determined as a function of that defined outline diameter. A disadvantage of this known system is that its accuracy is insufficient in several applications and external influences, in particular, are not adequately taken into account.
To eliminate these disadvantages it has already been suggested to add to the camera imaging the first area of the crystal a second camera which images a second portion of the crystal; the diameter of the crystal is determined in an evaluation circuit using the images of both cameras (unpublished patent application 197 38 438.2). In this manner it is possible to precisely record the actual crystal diameter in all phases of the cultivation process. The melting process itself cannot be monitored with the proposed device.
An object of the invention is to overcome the problem of monitoring the melting process for the basic materials from which monocrystals are drawn.
SUMMARY OF THE INVENTION
The above and other objects of the invention can be achieved with a device for monitoring a melt for the production of crystals, wherein a camera is provided which images at least portions of the surface of the contents of a crucible and with an evaluating device provided which evaluates the camera's images with respect to solid and liquid portions of the surface of the crucible contents.
A feature of the invention resides in a process for monitoring a melt serving the production of crystals, wherein:
a) at least portions of the surface of the contents of the crucible are imaged with a camera; and,
b) the image made by the camera is evaluated with respect to solid and liquid components on the surface of the contents of the crucible.
The advantage achieved with the invention particularly consists in shortening the process time, avoiding overheating of the melt and the crucible, and minimizing the O 2 content of the melt. The use of a special sensor thus makes it possible to implement a melt control before complete fusion of the molten material. In addition, individual differences can be identified per batch and taken into account.
BRIEF DESCRIPTION OF DRAWINGS
An example of embodiment of the invention is shown in the drawings and is described below in greater detail. Shown are:
FIG. 1 is a general depiction of the device according to the invention;
FIG. 2 a is a top view of a crucible containing molten material;
FIG. 2 b is a graphic depiction of the brightness distribution along a horizontal line on the crucible;
FIG. 3 is an enlarged depiction of the measuring window of a camera directed at the surface of a crucible; and
FIG. 4 is a flow chart for the process of identifying solid or liquid components of the melt.
DETAILED DESCRIPTION OF INVENTION
FIG. 1 shows a device which makes it possible to identify the fusion of molten material at an early stage. This device is based on an optical principle according to which those areas of a melt that are liquid emit less visible light than areas that are still solid or that have solidified out of the melt. Instead of, or in addition to, this brightness principle, the principle of hue or chrome and/or color saturation can be used—inasmuch as molten materials differ from non-molten materials not only in brightness but also in chrome and/or color saturation.
To identify the brightness of the melt, a camera 2 is provided; the camera can be a CCD video camera. This camera 2 is positioned diagonally over the crucible 7 in which the melt 3 is located. The camera 2 is used to observe the surface 4 of the melt 3 , or at least a portion of this surface 4 .
The crucible 7 can be moved by means of a shaft 5 and a gear 6 using a motor 9 , for example, from above downwards. It is also possible to make it rotate. The crucible 7 is located in a housing consisting of an upper part 12 , a middle part 13 , and a lower part 14 . The lower part 14 is furnished with two gas outlets 25 , 26 . An electrical heating system 16 is positioned around the crucible 7 and is provided with electrical energy from a heater current source 17 . Parts that are not depicted can brought into the proximity of the melt 3 with a threaded rod 18 driven by a motor 19 . The threaded rod 18 is enclosed in a cylindrical unit or pipe 23 belonging to the upper part 12 , which is provided with a gas inlet opening 24 .
The output signals of camera 2 are fed to an image evaluating unit 37 , which exchanges data with a control unit 38 . This control unit 38 can be influenced by means of an operating unit 39 , for example, a keyboard. The control unit 38 makes it possible to control the drive 6 , 9 for the crucible 7 and to control the heater current source 17 .
FIG. 2 a depicts the crucible 7 in a view from above. Located in the crucible 7 is liquid material 50 , e.g., liquid silicon, in which there are several islands 51 to 54 of hardened material. The liquid melt 50 emits less brightness than the hardened islands 51 - 54 , because the hardened material better reflects visible light than the liquid material. As a result, the islands 51 - 54 have a brighter appearance than the surrounding liquid material 50 .
Reference numeral 55 designates a measuring window which corresponds to the viewing angle of the camera 2 , i.e., the camera 2 records the area of the crucible 7 defined by the measuring window 55 . Reference numeral 56 designates a measuring line whose meaning will be explained below.
In FIG. 2 b the brightness of the crucible contents is depicted in an x coordinate system. It will be seen that those points where solid islands 51 - 54 are located exhibit a greater brightness B 1 . . . B 4 than at those points where the liquid melt is located.
If only the islands 52 , 53 through which measuring line 56 passes are taken into account, then brightnesses B 1 and B 3 in FIG. 2 b would fall out.
FIG. 3 again shows the measuring window 55 with the melt 50 and the islands 51 to 54 located therein, but on an enlarged scale. Superimposed on the measuring window are a number of horizontal and vertical measuring lines 60 to 69 and 70 to 86 , so as to form a lattice. These measuring lines 60 to 69 and 70 to 86 are scanning lines and columns for the CCD camera 2 . The measuring window recorded by the CCD camera 2 is thus scanned line by line or column by column, i.e., the scanning lines and columns shown in FIG. 3 are approached in time-multiplex fashion.
With this kind of scanning, the brightness transitions between solid and liquid Si are recorded; this is marked by points P 1 . . . P 9 with reference to island 52 . By identifying these brightness transitions, it is possible to precisely establish the aggregate state of the surface of the Si melt.
If the individual points P 1 . . . P 9 are known, the surface area of the island 52 can be calculated. The surface areas of the other islands 51 , 53 , 54 can be calculated in corresponding fashion. This in turn creates the possibility of determining the ratio of liquid surface to solid surface. Different values can be established for these ratios, which, when reached, will result in the execution of certain procedural steps. Of particular interest here is the disappearance of the solid surface portion of the melt, since this state indicates a finished melt. Since the disappearance of solid bodies can be simulated by natural events, a predetermined waiting period is observed during which the crucible continues to rotate. Only after this waiting period is over is it assumed that the solid parts of the surface have actually disappeared; the appropriate procedural step is then initiated.
FIG. 4 shows the process flow of the invention in the form of a flow chart. After the startup indicated by block 100 , the surface of the melt reproduced by the CCD camera 2 is read as an image in digital form into a storage unit (not shown), as suggested by block 101 . The image thus read in is now scanned line by line and/or column by column, cf. block 102 , and monitored for brightness. Whenever the difference in brightness between adjacent points of a line and/or column exceeds a predetermined threshold value, the local coordinate of the transition point—the so-called edge—is identified and stored, cf. block 103 .
In this manner it is possible to locate, e.g., points P 1 . . . P 9 of island 52 . With a suitable interpolative process a path can be drawn joining these points P 1 . . . P 9 , giving the outline of island 52 . From this the surface area of the island 52 can be calculated.
If the islands 51 to 54 become larger or increase in number, the number of identified edges also increases. The number of identified edges is thus a measure of the molten state on the surface of the melt. If a specific melt value is established for the number of edges—cf. block 104 —a predetermined melt-solid body behavior can be defined, arrival at which will trigger a given process step. This is indicated by block 105 . A process step of this kind might be, for example, a reduction in the heat in heating element 16 or an increase in the crucible's rate of revolution. When all process steps have been executed, the process can be terminated.
The threshold value for the number of edges could be input via, e.g., the operating unit 39 .
The invention thus makes it possible to monitor and influence the individual steps in the production of a crystal, even at an early point in the process. If solid semiconductor lumps, for example, are left hanging on the wall of the crucible or if lumps drifting in the melt threaten to touch equipment above the melt, and to damage it, the heating output, for example, and/or the rate of rotation of the crucible can be modified appropriately in order to accelerate the melting process.
If the process according to the invention establishes that the solid/liquid ratio=0, a waiting period of 1 to 5 minutes is introduced, until the next process step is introduced, since, as mentioned above, disruptive influences can simulate a complete liquefaction of the melt when some unmolten parts still remain in it. This waiting period assures that all material has actually melted and that the process of drawing a crystal can begin. The length of the waiting period depends on the crucible's rate of rotation. If the crucible is rotated quickly, the waiting period can be shortened, since the increased rate of rotation will more rapidly bring the unmelted lumps into the area where they are melted.
Further variations and modifications of the foregoing will be apparent to those skilled in the art and are intended to be encompassed by the claims appended hereto.
German priority applications 197 38 438.2 and 198 17 709.7 are relied on and incorporated herein by reference.
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A device for monitoring a melt for the production of crystals. A camera is provided which images at least portions of the surface of the contents of a crucible. An evaluating device is used to evaluate the camera's images with respect to solid and liquid portions of the surface of the crucible contents.
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BACKGROUND
Processes for extracting numerous compounds from organic materials, particularly from plants, using supercritical fluid extraction (SFE) are known. Generally, above a critical temperature (T c ) and pressure (P c ), a vapor and a liquid of the same substance have the same density; in this state the fluid cannot be liquified by further increasing the pressure. A supercritical fluid state results when the substance is maintained at its T c and P c whereby a transition from gas/liquid to supercritical liquid occurs. For example, a description of the phase changes in a gas (CO 2 ) and the conditions at which the gas becomes a supercritical fluid (SCF) is known, as described in U.S. Pat. No. 4,749,522.
U.S. Pat. No. 3,899,398 to Cole et al. teaches a process for treating citrus wastes to obtain essential oils by cooking the citrus wastes in the aqueous phase under autogeneous pressure at a temperature of about 350° C. to 750° C., in the absence of air or oxygen.
U.S. Pat. No. 4,749,522 to Kamarei discloses supercritical fluid extraction of animal derived materials and provides generalized teachings that numerous methods can be used to prepared non-dried animal tissues used in the supercritical extraction process, including grinding, crushing, cumminuting, high and low pressure pressing, cryogrinding, flaking, sonication, freezing, freeze-thaw treatment, freeze drying, emulsification, homogenization, filtration, high speed mixing, centrifugation, cell separation, mechanical separation, thermal treatment, and other physical treatment such as treatment with inorganic and organic acids, bases, solvents, surface active agents, colorants, ionization radiation treatment; enzymatic treatment such as endogenous and/or exogenous enzymatic treatment, and any combination of more than one of the above methods of treating the sample. However, in none of his examples does Kamarei teach using treatment with acids of any kind. Nor does Kamarei suggest the use of his process for treating plant materials.
U.S. Pat. No. 4,824,570 discloses a process for supercritical extraction of essential oils from plants with carbon dioxide for preparing pharmaceutical products.
Bonnie A. Charpentier and Michael R. Sevenants (eds.), Supercritical Fluid Extraction and Chromatography, Techniques and Applications, ACS Symposium Series 366, American Chemical Society, Washington, D.C. (1988) discloses, for example, the ultrasonic supercritical fluid extraction (sfe) of caffeine from roasted coffee beans, of omega-3 fatty acids from fish oil and of terpenes from orange essential oil. Carpentier and Sevenants also discloses in Chapter 7, steps to developing a commercial supercritical carbon dioxide processing plant, and teaches that most solvent extraction using CO 2 are run at temperatures between 10° C. and 50° C., mild temperatures which are not likely to degrade or volatize heat-sensitive aroma compounds. The authors further teach that some materials may require pre-treatment processing (i.e. physical methods) to prepare the material for extraction or post-treatment of the residue after extraction is completed, further stating that materials handling systems such as conveyors and product silos must be designed with these considerations in mind.
Bioprocessing Technology, a monthly intelligence service from Technical Insights, Inc., Vol. 11, Number 11, November 1988 discloses that supercritical fluids, using as its solvent carbon dioxide, can be used to isolate diosgenin, a building block for sterols from plant cell culture.
J. M. Wong and K. P. Johnston, Biotechnology Progress, Vol. 2, No. 1, March 1986, pp. 29-39 teach the solubilization of biomolecules, such as sterols, in carbon dioxide based supercritical fluids.
L. Sanchez et al., Analyst (London) 97 (1161) pp. 973-6 (Chem. Abstract 78(13):81734c) teach that crude diosgenin was obtained from barbasco root by hydrolysis with 30% HCl followed by extraction with CHCl 3 .
None of these references teach supercritical fluid extraction of compounds from plant materials which were hydrolyzed either prior to or during contacting with a supercritical fluid.
SUMMARY OF THE INVENTION
The present invention is directed toward a process for extracting a compound from plant material, comprising
a) contacting hydrolyzed plant material with a supercritical fluid, optionally with a co-solvent, and
b) recovering the compound from the supercritical fluid.
In another embodiment, the present invention is directed toward a process for removing a compound from plant material, comprising contacting the plant material with an acid, a supercritical fluid and a co-solvent, and recovering the compound from the supercritical fluid.
One advantage of the present invention is that it provides a process for extracting compounds having pharmaceutical utility from plant material in excellent yields and of high purity.
A second advantage of the present process is that it can utilize either fresh or dried plant materials, thus making the process extremely versatile in conjunction with off-site harvesting practices.
A third advantage of the present process it that it can utilize coarsely ground plant material, thus simplifying physical pretreatment operations, such as grinding and sieving.
A fourth advantage is that the present process generates considerably less waste, i.e. solvents, requiring much less handling and disposal than other known processes for extracting compounds from plant material.
A fifth advantage is that the present process is easily amenable to automation procedures and online analysis of the compounds being extracted from said plant materials.
DETAILED DESCRIPTION OF THE INVENTION
Throughout the specification, the terms "removal" and "extraction" have the same meaning and are used interchangeably.
An apparatus for supercritical extraction is made up of a extraction cell, preferably cylindrical, which is housed in a chamber for controlling temperatures and pressures. A supercritical fluid (ie. extracting mobile phase), such as CO 2 , is pumped into the extraction cell, through a pressure regulating restrictor and into a vessel which serves as a trap. Pressure is maintained by back pressure regulators. As the supercritical fluid passes through the plant material containing the desired compound, the supercritical fluid removes the compound from the plant material. As the supercritical fluid containing the desired compound leaves the chamber, the fluid transforms into a gas, which passes through or is injected into (i.e. bubbling) a trapping vessel. The desired compound extracted from the plant material is concentrated in the trapping vessel.
The plant material can include the entire plant itself or any part thereof, including the roots, stems, leaves, fruits, flowers, seeds, tubers and the like, such as Barbasco root and Yucca seed.
Generally, the compound being extracted from the plant material should be resistant to hydrolysis by acid, although a compound which is oxidized or derivatized compounds can also be extracted. A compound is considered resistant to hydrolysis if the compound is not degraded by acid hydrolysis, even though certain acid labile moieties, e.g. esters, aldehydes, ketones, ethers, unsaturated double and triple bonds, etc. may undergo reaction with the acid and/or solvent. Where an oxidized or derivatized compound is extracted, the compound can be used as is, or can be converted to its original form by conventional procedures, e.g. reduction, esterification, addition, etc. as described in J. March, Advanced Organic Chemistry, 3rd Edition, John Wiley and Sons, New York, N.Y., (1985), 1346 pages.
Thus, the present process is useful for extracting from plant materials sterol compounds such as diosgenin, sarsasapogenin or cholestorol, and fatty acids such as C-8 to C-24 fatty acids, including octanoic acid, hexadecanoic acid, tetradecanoic acid and the like.
In the present process, hydrolyzed plant material can be prepared by treatment of fresh or dried plant material with acid under conditions effective to promote hydrolysis. Although partially hydrolyzed plant material can used in the present process, it is preferred that the plant material is completely hydrolyzed to maximize yields of the desired compound from the plant material. Useful acids for hydrolyzing the plant material can include mineral acids such as sulfuric acid (H 2 SO 4 ), hydrochloric acid (HCl) or phosphoric acid (H 3 PO 4 ); or organic acids such as formic acid, acetic acid, propanoic acid, butyric acid, o-, m- or p-toluene sulfonic acid, benzoic acid, trichloroacetic acid, trifluoroacetic acid; or mixtures of any of the above acids.
The acid can be employed in amounts sufficient to at least partially hydrolyze the plant material either prior to or during treatment with the supercritical fluid. Such amounts can range from excess to about equimolar amounts of acid per mole of compound anticipated to be removed or extracted from the plant material, preferably from about 100 to about 10 moles acid per mole of compound being extracted, more preferably from about 75 to about 25 moles of acid, most preferably about 50 moles acid. For example, if it is anticipated a barbasco root contains about 5% diosgenin, a treatment of about 50 moles acid per mole of diosgenin would utilize about one gram of acid per 0.5 gram of root material to completely hydrolyze the root material.
The acid solution should be thoroughly mixed with the plant material to allow maximum contact and penetration by the acid, by employing methods such as shaking, stirring, vortexing or sonicating the acid and plant material.
The plant material can be hydrolyzed with the acid at temperatures and pressures effective to promote hydrolysis of the plant material. Such temperatures can range from about ambient to about the boiling point of the acid solution, such as from about 25° C. to about 300° C., more preferably about 110° C. The pressures can range from ambient to the elevated pressures associated with the increased temperatures of the acid in the reactor.
Optionally, base can be added during or at the completion of hydrolysis of the root to neutralize any excess acid. Suitable bases include hydroxides, carbonates and bicarbonates of an alkali metal such as sodium, lithium, potassium or of an alkaline earth metal such as calcium or magnesium. Preferably the base is lime or sodium hydroxide, due their lower costs and availability. The base can be employed in amounts ranging from excess to about equimolar amounts of acid associated with the root and/or reaction mixture.
The supercritical fluid employed in the present process can be any of those described in U.S. Pat. No. 4,749,522. Representative extracting (solvating) mobile phase components include the elemental gases such as helium, argon, nitrogen and the like; inorganic compounds such as ammonia, carbon dioxide, water, and the like; organic compounds such as C-1 to C-5 alkanes or alkyl halides such as monofluoro methane, butane, propane carbon tetrachloride, and the like; or combinations of any of the above. A supercritical fluid can be modified by the addition of inorganic and/or organic compounds as listed above, called modifiers. Most preferably, the supercritical fluid is carbon dioxide admixed with chloroform. Not all the fluids described above will be suitable for extracting a desired compound from plant material. However, by determining the known properties of the desired compound as well as the gas specifications, including supercritical temperatures and pressures, one of ordinary skill in the art can select those components or any combinations thereof suitable for the extraction process.
The cosolvent employed in the present process should be compatible with the supercritical fluid selected and also be capable of at least partially dissolving the compound being extracted. Suitable co-solvents for use in conjunction with the supercritical fluid include aromatics such as xylene, toluene and benzene; aliphatics such as C-5 to C-20 alkanes including hexane, heptane and octane; water; C-1 to C-10 alcohols such as methanol, ethanol, propanol, butanol and isopropanol; ethers; acetone; chlorinated hydrocarbons such as chloroform, carbon tetrachloride or methylene chloride; or mixtures of any of the above. The co-solvent can be employed in amounts effective to aid in the wetting and/or hydrolysis of the plant material, and can range from excess to about one volume of solvent per one volume of acid, preferably from about 10 to one volume of solvent per one volume of acid. Where non-hydrolyzed plant material is used, a solvent should be used. However, where hydrolyzed plant material is used, the process can be conducted optionally with a solvent such as any of those described above; or the process using hydrolyzed plant materials (e.g. pre-hydrolyzed plant materials) can be conducted without a solvent. Preferably the process using hydrolyzed materials does not use a solvent.
The plant material can be contacted with the supercritical fluid at temperatures ranging from about 30° C. to about 300° C., preferably from about 75° C. to about 250° C. The pressure employed should be sufficient to maintain the supercritical fluid, and can be increased from ambient atmospheric pressure to about 400 atmospheres or more, preferably between about 100 and 300 atmospheres. Preferably the apparatus is programmed to maintain slow, incremental increases in pressure to achieve efficient extraction of the compound from the plant material and avoid abrupt sample movements or plugging of the output lines.
The compound being extracted can be recovered from the supercritical fluid by passing through or injecting the mobile phase into a trapping solvent within which the desired compound is readily soluble, such as any of the solvents described above for use with the supercritical fluid. The compound can be recovered from the trapping solvent using conventional recovery procedures such as evaporation, distillation, phase separation, or crystallization or filtration.
EXAMPLE 1
Extraction of Diosgenin from Fresh Barbasco Root Hydrolyzed During Supercritical Fluid Extraction ##STR1##
To a ten mL stainless steel extraction cell is added 0.5 g dried, coarsely ground barbasco root, 2 mL of isopropyl alcohol and 2 mL of 3N para-toluene sulfonic acid (PTSA). The extraction cell is sonicated for 15 minutes to mix the contents of the extraction cell. The extraction cell is opened and about one inch of prewashed sand is added and packed at the fritted restrictor end of the cell (i.e. output). The extraction cell is closed and inserted into a supercritical extraction unit with the sand filled end attached to the restrictor. The input is attached to the opposite end. The operating conditions are as follows:
______________________________________Head Space Filler: HeliumRestrictor Flow: 500 mL/minExtracting Mobile Phase Supercritical fluid grade(i.e. supercritical fluid): CO.sub.2 modified with 10% chloroformOven Temperature: 250° C.Trapping Solvent: ToluenePressure Program: a. 100 atm. for 2 minutes b. 200 atm. for 2 minutes c. 225 atm. for 2 minutes d. 250 atm. for 2 minutes e. 275 atm. for 2 minutes f. 300 atm. for 60 minutesTotal Extraction Time: 70 minutes______________________________________
Analysis of the trapping solvent containing the extracted compound by supercritical fluid chromatography (SFC) and comparison with known standards indicates that 100+10% of the diosgenin from the barbasco root, depending upon sample homogeneity, is extracted.
EXAMPLE 2
Extraction of Diosgenin From Dry Barbasco Root Which is Acid Hydrolyzed Prior to Supercritical Fluid Extraction
a. Hydrolysis of root. To a five liter glass lined, three-necked reactor equipped with an overhead stirrer, thermometer, condenser, addition funnel and agitator, is added 1860 ml tap water and 282 g sulfuric acid. Under agitation, the flask is charged with 1000 g of air dried barbasco roots (equivalent to about 40 g diosgenin). The reactor is closed and heated with steam to a temperature of 110° C. for two hours, during which time 592 ml water is added. The reaction mixture is cooled to 90° C., the reactor is vented to allow the air space within the reactor to equilibrate to atmospheric pressure, and the reactor is charged with 1200 mL of hot water. The acidified water is drained from the roots. The roots are washed with additional hot water, flushed with steam for 30 minutes and dried at 80° C. overnight to give hydrolyzed roots.
b. Supercritical fluid extraction. Essentially the same procedure as in Example 1 is employed, except that sonication is eliminated and only hydrolyzed barbasco root from step a. and prewashed sand are added to the extraction cell. Analysis of the trapping solvent indicates that 100±10% of the diosgenin from the barbasco root is extracted.
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The present invention is directed toward a process for extracting compounds from plant material, comprising
a) contacting hydrolyzed plant material with a supercritical fluid and optionally with a co-solvent and p1 b) recovering the compound from the supercritical fluid.
In another embodiment, the present invention is directed toward a process for removing a compound from plant material, comprising contacting the plant material with an acid, a supercritical fluid and a co-solvent, and recovering the compound from the supercritical fluid. The sterols, diosgenin and sarsapogenin, are efficiently extracted from barbasco root and Yucca seed, respectively.
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RELATED APPLICATION DATA
[0001] This application is a divisional of U.S. application Ser. No. 10/605,852 filed on Oct. 30, 2003, entitled “Control Cable Adjustment Device.”
BACKGROUND OF THE INVENTION
[0002] The present invention relates to adjustment devices for adjusting the length of a control cable and more particularly to an adjustment device for adjusting a shifting cable or brake cable for a bicycle.
[0003] Control cable adjustment devices are used to adjust the length of a control cable or Bowden cable that connects a gear shifter to a gear change mechanism such as a derailleur or internal gear hub or connects a brake lever to a brake. The control cable includes an inner wire that slides within an outer casing or sheath. The length of the cable needs to be adjusted because elongation of the cable occurs after extended use under load and shifting or braking requires precise cable guidance. Usually the adjustment device is threaded into the shifter or brake housing, resulting in the adjustment device being indirectly braced against the bicycle frame. When the adjustment device is threaded into the housing, the sheath is shortened relative to the inner wire, which then moves loosely in the sheath.
[0004] To tighten the control cable, the adjustment device is unscrewed from the housing, resulting in the sheath being elongated relative to the inner wire. Usually the adjustment device includes a locknut or detent mechanism that holds the adjustment device in its current position and also prevents the adjustment device from being rotated in an uncontrolled manner. Various detent mechanisms are shown in U.S. Pat. No. 5,674,142; U.S. Pat. No. 4,833,937, EP 0 916 570 A2, and German Utility Model DE-GM 76 26 479.
[0005] U.S. Pat. No. 5,674,142 discloses an adjustment device having an elongated retention nut that is threaded onto an elongated mounting member of a shifter housing. The device includes a detent mechanism having detents located on an inner surface of the retention nut that are engageable with protrusions on an outer surface of the mounting member. The protrusions are located adjacent the inner end of the threads on the mounting member. A problem with this configuration is that by arranging the threads and the protrusions adjacent one another, the adjustment device is relatively long.
[0006] U.S. Pat. No. 4,833,937 discloses a detent mechanism that includes a disk rotatably connected to the adjuster and having protrusions which is biased by a spring to engage detents located on the outer surface of a stop nonrotatably connected to a shifter housing. When the adjuster is rotated the disk rotates between the protrusions to provide stepwise adjustment of a control cable. A problem with this configuration is that it requires a lot of components and requires a cover for the detent mechanism, which also unnecessarily enlarges the outside diameter of the adjustment device.
[0007] In EP 0 916 570 A2, the detent mechanism includes a spring having a first end that is secured in a slot of a brake lever housing and a second end that engages a channel in the outside diameter of the adjuster. After each complete adjustment revolution, the end of the spring element snaps into the channel provided for the control cable on the adjuster. Although this adjustment device has fewer components than the previous mentioned adjustment devices, it requires an additional slot in the brake housing to receive one end of the spring. Another problem with this configuration is that the spring reengages the insertion slot in the adjuster only after each complete revolution of the adjuster, resulting in only coarse control cable adjustment.
[0008] The detent mechanism described in DE-GM 76 26 479 generally includes an adjustment nut having external longitudinal flutes and a screw thread that is surrounded by flexible retention arms which engage the longitudinal flutes to provide the detent function. A problem with this configuration is that the externally located flexible retention arms unnecessarily enlarge the outside diameter of the adjustment device and requires a cover to prevent soiling of the detent mechanism. Therefore there is a need for a control cable adjustment device that is compact and has minimal parts.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a reliable adjustment device for shifter cables and brake cables that is economical in terms of both manufacture and installation.
[0010] This is achieved in the present invention by using components that perform multiple functions and by skillfully arranging a spring element in the adjustment device. A spring element that is already present in the control mechanism may used for a detent mechanism of the adjustment device. For example, a return spring for a release lever of a shifter, a spring on a release slider, a cable spool spring or a recovery spring for a brake lever may be additionally used as a retention spring in the detent mechanism. If these springs are too soft or too far away from the adjustment device, the spring may be stiffened and braced by suitable bracing in or on the shifter or brake lever housing. If no suitable spring of the shifter or brake lever is available, then at least an existing insertion slot required for insertion of the control cable braces the spring element required for the detent operation. Therefore, the present invention requires either no additional spring element by using an existing spring in the control mechanism or eliminates the need to have an additional slot in the shifter or brake lever housing to brace the spring element by using a control cable insertion slot already present in the shifter or brake lever housing.
[0011] The present invention provides a control cable adjustment device for adjusting a control cable extending between a control mechanism such as a shifter or brake lever and an operating mechanism such as a derailleur or brake. The adjustment device includes an adjuster rotatably connected to a housing of the shifter or brake lever and a spring element. Together the adjuster and the spring element constitute a detent mechanism. The adjuster has a first end that receives the outer casing or sheath of the control cable and a second end that has threads that are received a threaded bore of the shifter or brake lever housing. The first end of the adjuster also has grip recesses to make it easier to rotate the adjuster. A detent contour extends coaxially through the second end of the adjuster and has radially inwardly directed holding contours.
[0012] The spring element has a retention segment or leg that engages the detent contour. The detent contour is provided with enough open space to avoid impeding the operation of the spring element or the control cable during adjustment of the cable. The cross section of the detent contour may be a polygon or round with flutes or elevations. The detent contour may also have different slopes to provide different rotational forces during rotation of the adjuster. For example the adjuster may have high rotational forces in the screwing in direction and low rotational forces in the screwing out direction. The spring element extends substantially parallel with the inner wire of the control cable extending through the adjuster.
[0013] The spring element may be a wireform spring that is preloaded and has two legs or segments that perform different functions. One segment may engage the detent contour to retain the adjuster in a current position and the other segment may function as a return spring for a release lever of a shifter or a recovery spring for a brake lever. To ensure that the retention segment does not move into the detent contour as the adjuster is rotated relative to the housing, the retention segment is braced in a cutout in the housing. The cutout prevents the retention segment from entering a cable insertion slot in the adjuster. Additionally, the cable insertion slot may be arranged to extend not parallel relative to the retention segment, for example, it extends at a 30 degree angle, to prevent the retention segment from entering the insertion opening. Also, a stop may be used to prevent the retention segment from entering the insertion opening.
[0014] To increase the detent and holding forces, the retention segment of the spring element may include two retention segments that are preloaded outward and are in equilibrium. The retention segments are braced against in the housing near the adjuster so that almost no bending moments and no torsion moments are introduced into the spring element upon rotation of the adjuster.
[0015] When it is not possible to use an existing spring element within the shifter or brake lever, an additional spring element must be provided to perform the detent function. In this embodiment of the present invention, a spring element is provided having at least two retention segments preloaded outward into the detent contour of the adjuster. To ensure that the spring element does not move upon rotation of the adjuster, the spring element includes a support segment that is braced against the housing. Once the control cable is installed, the spring element may be inserted easily and without tools into the detent contour of the adjuster and the cable insertion slot.
[0016] The present invention is not limited to the adjusting of a control cable for a gear shifter or a brake lever for a bicycle but can also be used wherever a defined, constant cable length or cable tension is required in a control cable. For example, clutch cables for motorized vehicles or other motion-related cables.
[0017] These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In the drawings:
[0019] FIG. 1 is a perspective view of a control cable adjustment device connected to a shifter in accordance with one embodiment of the present invention;
[0020] FIG. 2 is a perspective view of a control cable adjustment device in accordance with another embodiment of the present invention;
[0021] FIG. 3 is a perspective view of a control cable adjustment device in accordance with another embodiment of the present invention;
[0022] FIG. 4 is a perspective view of a control cable adjustment device in accordance with another embodiment of the present invention; and
[0023] FIG. 5 is a perspective view of a control cable adjustment device in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION
[0024] FIG. 1 shows a control cable adjustment device 20 connected to a bicycle shifter 21 in accordance with one embodiment of the present invention. The control cable adjustment device 20 adjusts the length of a control cable (not shown) having an outer casing or sheath and an inner wire that extends between a control mechanism such as the bicycle shifter 21 or brake lever and an operating mechanism such as a derailleur or brake. The control cable adjustment device 20 controls the length of the control cable by moving the sheath relative to the inner wire. The shifter 21 generally includes a housing 4 mountable to a handlebar of a bicycle and a lever 8 movably or pivotally coupled to the housing 4 . The lever 8 may be biased by a return spring toward a neutral position. The shifter housing 4 includes a cable guide 13 having an internally threaded bore 15 for receiving the adjustment device 20 .
[0025] The adjustment device 20 generally includes an adjuster 1 and a spring element 2 . The adjuster 1 has first and second ends. At the first end 22 is a receiving bore for the sheath of the control cable and grip recesses 3 to facilitate the turning of the adjuster 1 relative to the housing 4 . At the second end 23 is a detent contour 5 and external threads 12 . The external threads 12 are screwed into the threaded bore 15 of the shifter housing 4 . A control cable insertion opening 14 extends along the adjuster 1 and the cable guide 13 , which allows the inner wire to be transversely inserted into the detent contour 5 of the adjuster 1 and the bore 15 of the cable guide 13 . Alternatively, the adjuster 1 may not have an insertion opening but has an unbroken or continuous periphery.
[0026] The spring element 2 has a retention segment or leg 6 that extends into the detent contour 5 and a spring segment 7 that extends into the shifter housing 4 . The detent contour 5 and the retention segment 6 extend coaxially with the external threads 12 on the adjuster 1 . To ensure that the retention segment 6 does not move in the detent contour 5 as the adjuster 1 is screwed in and out of the shifter housing 4 , the retention segment 6 is braced in a cutout 9 in the shifter housing 4 . The height of the cutout 9 is such that it braces the retention segment 6 but also allows passage of the inner wire. The cutout 9 also prevents the retention segment 6 from jamming in the insertion opening 14 . Further, the detent contour 5 has enough free space to not impede the operation of the control cable or the retention segment 6 . The spring element 2 is guided through the shifter housing 4 around a centrally located shifting mechanism 11 and is held by a brace 10 which allows the two segments 6 , 7 to function as two springs relatively independent of one another.
[0027] FIG. 2 illustrates a similar adjuster 1 as shown in FIG. 1 except that the detent contour 5 has a cross section in the shape of a rectangle with rounded corners. However, the cross section can be various different shapes, for example, a circle with flutes 36 to receive the retention segment 6 (see FIG. 3 ) or, as shown in FIG. 1 , a polygon with convex sides. The cross section of the detent contour 5 can also have varying surfaces configured to engage the retention segment 6 such that different forces occur when adjuster 1 is screwed in or out. Preferably, there are high rotational forces in the screwing direction A and low rotational forces in the unscrewing direction B.
[0028] FIG. 3 shows another embodiment of the present invention wherein an adjuster 24 has a control cable insertion slot 25 that extends obliquely, rather than parallel to the inner wire of the control cable as shown in FIG. 2 and a spring element 26 having a retention segment, in this embodiment, two flexible segments 27 . The oblique profile of the control cable insertion slot 25 prevents the retention segments 27 , which extends parallel to the control cable, from penetrating into the control cable insertion slot 25 . In the installed state, when the threads 12 are screwed into the threaded bore 15 on the housing segment 13 , the retention segments 27 engage the detent contour 5 . In this embodiment, the spring element 26 functions only as a detent spring. Another segment 38 of the spring element 26 is braced around a fixed point 16 on a housing (not shown) similar to the housing 4 shown in FIG. 1 and the retention segments 27 , which are preloaded in the direction of the detent contour 5 , extend into the adjuster 24 . The adjuster 24 has pronounced grip recesses 28 to allow easy adjustment of the control cable. This embodiment of the control cable adjustment device is particularly suitable for twist-grip shifters and brake actuation systems.
[0029] FIGS. 4 and 5 show other embodiments of the present invention wherein a spring element 29 is braced against a brace 30 in a brake lever housing 17 , see FIG. 4 , and is braced in a control cable insertion slot 31 , see FIG. 5 . The spring element 29 has retention segments 32 that, in the installed state, extend into the detent contour 5 of the adjuster 1 . To ensure that the retention segments 32 do not become jammed in the insertion slot 31 , the movement of the retention segments 32 is restricted by a stop 19 located on the brake housing 17 . Further, the spring element 29 is placed around the brace 30 to ensure that it remains in a defined position in the brake housing 17 .
[0030] The adjuster 1 has threads 12 that are screwed into a threaded bore 34 of the brake housing 17 . When the control cable insertion slots 31 of the adjuster 1 and the brake lever housing 17 are aligned with one another, the control cable can be hooked onto the brake lever and inserted into the control cable insertion slot 31 . To insert the one end of the spring element 29 into the adjuster 1 and to insert the other end of the spring element 29 into the control cable insertion slot 31 on the brake lever housing 17 , the brake lever must be depressed. The spring element 29 includes a support segment 18 that is inserted into the control cable insertion slot 31 of the brake housing 17 and having a configuration such that the spring element 29 is prevented from rotating. When the spring element 29 is installed, it is prevented from falling out of the brake housing 17 by the preload force of the retention segments 32 directed against the detent contour 5 and by the brake lever when it is not depressed.
[0031] While this invention has been described by reference to specific embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.
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A control cable adjustment device for adjusting a control cable extending between a control mechanism and an operating mechanism. The adjustment device includes an adjuster rotatably connected to a housing of the control mechanism and a spring element having at least one retention segment. The retention segment engages a detent contour of the adjuster to retain the adjuster in its current position. Another segment of the spring element may have a second function as a return spring for a gear shifter or a brake lever.
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This application is a 371 of PCT/JP94/01332, filed Aug. 11, 1994.
FIELD OF THE INDUSTRIAL UTILIZATION
The present invention relates to novel benzylamine derivatives and their salts.
BACKGROUND ART
As to the current human society is becoming increasingly complex in structure and mechanism, so that people undergo increasing stresses of various kinds. In such an ever-changing society, the number of people suffering from mental disorder, particularly depression and anxiety neurosis are increasing, posing a big social problem.
Unlike the typical depression seen in the past, depression appearing currently is relatively slight and tends to become chronic, in many cases. Depression is often difficult to distinguish from neurosis and tends to become chronic. It is reported that most of the patients of chronic depression have neurosis as well and that the number of depression patients is increasing more and more in recent years (cf. Japanese Journal of Clinical Psychiatry, Vol. 21, No. 4, pp. 691-695, 1992).
Thus, the features of mental disorder are becoming more complex as the structure and mechanism of society become complex. The following two facts are pointed out as the recent major changes in the features of metal disorder.
(1) In neurosis, those neuroses are increasing which show depressive syndrome and which are difficult to distinguish from depression.
(2) Among the patients which have been judged to have neurosis, patients of slight depression are included. Among, in particular, the patients which have been judged to have neurosis because of their anxiety attack and expectation fear, patients of slight depression are included at a fairly high ratio (cf. Japanese Journal of Clinical Psychiatry, Vol. 21, No. 4, pp. 691-695, 1992).
According to a clinical research (cf. "Anxious Depression" edited by Racagni G. Smeraldi, Raven Press, N.Y., 1987), analysis of the symptoms of the patients who had been judged to have serious depression, indicated that the symptoms comprised worry of intermediate level (72%), psychological anxiety (62%), physical anxiety (of autonomic nervous system and muscle system) (42%), fear attack (29%), fear symptom (19%) and obsessive-compulsive symptom (1.2%). Patients of depression include patients of anxiety symptom at a high ratio.
Mental disorder which show complex and diversified symptoms as mentioned above, are currently treated, in many cases, with an antidepressant, an antianxiety agent or a combination thereof, depending upon the symptoms. Such treatment is effective in some cases but is said to be insufficient in most cases. Conventional antidepressants are effective for endogeneous depression, but are not sufficiently effective for character-originated depression or highly neurotic depression (cf. Journal of Neuropsychopharmacology, Vol. 9, No. 4, pp. 279-285, 1987). Use of antianxiety agent by patients who show anxiety symptom on the surface while actually having a depressive phase, prolongs the depression in some cases (cf. Japanese Journal of Clinical Psychiatry, Vol. 21, No. 4, pp. 691-695, 1992). Use of antidepressant based on the indiscreet judgement by clinical department other than psychiatry department, may overlook suicidal ideation and induce the prolongation of depression (cf. Journal of Neuropsychopharmacology, Vol. 9, No. 4, pp. 279-285, 1987).
Conventional antidepressants have problems; that is, (1) they show no immediate effect and need to be administered continuously for at least 2 weeks, (2) they have undesirable side effects such as anti-cholinergic effect and the like and (3) they are ineffective in some cases (effective ratio: 65%) (cf. Journal of Neuropsychopharmacology, Vol. 11, No. 10, pp. 753-761, 1989). Conventional antianxiety agents have problems; that is, (1) they have side effects such as excessive sedation, somnolence, muscle relaxation and the like and (2) there often appear serious adverse symptoms such as dependency, abstinence symptom, memory impairment and the like (cf. Journal of Neuropsychopharmacology, Vol. 11. No. 9, pp. 709-719, 1989).
Single or combination use by patients, of antidepressant and antianxiety agent which, as mentioned above, have many side effects and many adverse effects and are said to be ineffective to the core symptoms of mental disorder, is considered to produce antinomy in the treatment of mental disorder. Hence, if there is developed a medicine which tackles the root cause of mental disorder and which shows both an anti-depression activity and an anti-anxiety activity, it will solve the above-mentioned problems associated with the treatment of mental disorder.
Compounds having chemical structures similar to those of the benzylamine derivatives of the present invention are disclosed in PCT International Applications WO 90/14334 (Publication Date: Nov. 29, 1990), WO 93/07113 (Publication date: Apr. 15, 1993), WO 91/09594 (Publication Date: Jul. 11, 1991) and WO 93/00313 (Publication Date: Jan. 7, 1993). Particularly in WO 91/09594 and WO 93/00313 are disclosed compounds represented by the following general formula: ##STR2## wherein: Ar is aryl or heteroaryl wherein aryl or heteroaryl can be substituted by hydrogen, halogen such as chloro, fluoro, bromo or iodo, CF 3 , C 1 -C 6 alkoxy, C 2 -C 6 dialkoxymethyl, C 1 -C 6 alkyl, cyano, C 3 -C 15 dialkylaminoalkyl, carboxy, carboxamino, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkylthio, allyl, aralkyl, C 3 -C 6 cycloalkyl, aroyl, aralkoxy, C 2 -C 6 acyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, an aryl ring fused to a substituted benzene ring, a substituted aryl ring fused to a benzene ring, a heteroaryl ring fused to a benzene ring, a substituted heteroaryl ring fused to a benzene ring, C 3 -C 6 heterocycloalkyl, a C 3 -C 6 heterocycloalkyl ring fused to a benzene ring, C 1 -C 6 alkylthio, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, arylthio, C 1 -C 6 haloalkoxy, amino, C 1 -C 6 alkylamino, C 2 -C 15 dialkylamino, hydroxy, carbamoyl, C 1 -C 6 N-alkylcarbamoyl, C 2 -C 15 N,N-dialkylcarbamoyl, nitro or C 2 -C 15 dialkylsulfamoyl;
R is hydrogen or C 1 -C 6 alkyl;
R 1 is selectively from the group consisting of hydrogen, C 1 -C 6 alkyl, hydroxy, amino, C 1 -C 6 alkylamino and ═O (a double bond oxygen); or
R and R 1 together form a morpholino ring;
n is 0-5;
W is --(CH 2 ) p -- or --H H-- wherein p is 1-3;
X is --(CH 2 ) q -- wherein q is 1-6, --(CH 2 ) r --C.tbd.C--(CH 2 ) r -- wherein each r is 0-3, --(CH 2 ) r --CH═CH--(CH 2 ) r --, ##STR3## --(CH 2 ) r --Y--(CH 2 ) r -- wherein Y is O or S, or C 1 -C 6 alkyl (wherein Z is hydrogen); and
Z is hydrogen, aryl, an aryl-substituted carboxylic acid group, heteroaryl or cycloalkyl, wherein aryl, heteroaryl and cycloalkyl can be substituted by hydrogen, halogen such as chloro, fluoro, bromo or iodo, CF 3 , C 1 -C 6 alkoxy, C 2 -C 6 dialkoxymethyl, C 1 -C 6 alkyl, cyano, C 3 -C 15 dialkylaminoalkyl, carboxy, carboxamido, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkylthio, allyl, aralkyl, C 3 -C 6 cycloalkyl, aroyl, aralkoxy, C 2 -C 6 carboxylic acyl, acyl, substituted aryl, heteroaryl, substituted heteroaryl, an aryl ring fused to a substituted benzene ring, a substituted aryl ring fused to a benzene ring, a heteroaryl ring fused to a benzene ring, a substituted heteroaryl ring fused to a benzene ring, C 3 -C 6 heterocycloalkyl, a C 3 -C 6 heterocycloalkyl ring fused to a benzene ring, C 1 -C 6 alkylthio, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, arylthio, C 1 -C 6 haloalkoxy, amino, C 1 -C 6 alkylamino, C 2 -C 15 dialkylamino, hydroxy, carbamoyl, C 1 -C 6 N-alkylcarbamoyl, C 2 -C 15 N,N-dialkylcarbamoyl, nitro, C 2 -C 15 dialkylsulfamoyl or an ortho methylenedioxy group.
According to said two literatures, the compounds of the above general formula are useful as a sigma-receptor ligand and can be used as a drug for schizophrenia or other psychosis, or for the treatment of central nervous system diseases, drug abuse, gastrointestinal diseases, hypertension, migrane, peritonsilitis, depression, etc.
Thus, the above-mentioned literatures disclose compounds having chemical structures similar to those of the present benzylamine derivatives, but do not disclose the present benzylamine derivatives per se.
Under the above situation, the present inventors made an extensive study and found out that the benzylamine derivatives represented by the above general formula (1) and their salts have both an anti-depression activity and an anti-anxiety activity and are effective as an excellent anti-depression and anti-anxiety drug. The present invention has been completed based on the finding. The benzylamine derivatives and their salts according to the present invention are characterized in that they are effective for amelioration of consciousness disturbance as well as for the treatment of obsessive-compulsive neurosis.
DISCLOSURE OF THE INVENTION
The benzylamine derivatives of the present invention are novel compounds not yet reported in any literature and are represented by the following general formula (1): ##STR4## wherein R 1 is a lower alkyl group; R 2 is a cycloalkyl group; and R 3 is a halogen atom.
The benzylamine derivatives represented by general formula (1) and their salts according to the present invention have both an anti-depression activity and an antianxiety activity and are effective as an excellent antidepression and anti-anxiety agent responding to the demand in medical care.
The benzylamine derivatives or their salts according to the present invention, having, in particular, an effect for activating the central nervous system and an effect for ameliorating disturbance of consciousness, are useful as a remedy for head trauma, cerebral hemorrhage, cerebral infarction, subarachnoidal hemorrhage, medical poisoning, atmospheric hypoxia, accident caused by anoxia, disturbance of consciousness after operation of the brain or after bypass operation of the heart, and the sequelae of said diseases such as mental growth retardation, lowering of attention response, language disorder, recognition disturbance, learning disability, hypokinetic syndrome, hypobulia, emotional disturbance and the like, and are also useful as an agent for ameliorating various diseases such as depressive state in senile dementia, delirium, language disorder, recognition disturbance, learning disability, hypokinetic syndrome, lowering of attention response, memory impairment with aging and the like. Further, the compounds of the present invention have a sigma receptor-agonistic action and are useful as a remedy for depression, anxiety neurosis, psychotic diseases caused by stress (e.g. psychosomatic disease), anorexia nervosa, hypopituitarism, hyperprolactinemia, cerebrovascular dementia, hyperkinetic syndrome, dementia-amnesia, Perkinson disease and the like. The compounds of the present invention can also be used as an antidepressant and an antianxiety agent.
The benzylamine derivatives and their salts according to the present invention show, also when orally administered, an anti-depression and anti-anxiety activity, an effect for activating the central nervous system, an effect for ameliorating disturbance of consciousness and a sigma receptor-agonistic action.
In the present complex society, a large number of people are suffering from mental disorders (e.g. obsessive-compulsive neurosis) caused by environmental stresses. The present compounds are useful as a remedy for obsessive-compulsive neurosis.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The groups used in the benzylamine derivatives represented by general formula (1) and their salts according to the present invention are specifically as follows.
The lower alkyl group represented by R 1 includes straight-chain or branched-chain alkyl groups of 1-6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl and the like.
The cycloalkyl group represented by R 2 can be exemplified by cycloalkyl groups of 3-8 carbon atoms, such as cyclopropyl, cyclopentyl, cyclobutyl, cyclohexyl, cycloheptyl, cyclooctyl and the like.
The halogen atom represented by R 3 includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.
Of the compounds of the present invention, preferable are compounds wherein R 1 is a methyl group or an ethyl group, R 2 is a cyclopropyl group, or a cyclobutyl group, and R 3 is a chlorine atom. Particularly preferable are compounds wherein R 1 is a methyl group, R 2 is a cyclopropyl group, and R 3 is a chlorine atom.
The benzylamine derivatives represented by general formula (1) according to the present invention can be produced by various processes. Preferable examples of the processes are shown below. ##STR5## wherein R 1 , R 2 and R 3 are the same as defined above.
In the Reaction formula-1, the reaction of the compound (2) with the compound (3) is conducted in the absence of any solvent or in the presence of an appropriate solvent, in the presence or absence of a dehydrating agent. The solvent includes, for example, alcohols such as methanol, ethanol, isopropanol and the like; aromatic hydrocarbons such as benzene, toluene, xylene and the like; halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride and the like; aprotic polar solvents such as dimethylformamide, dimethylacetamide, N-methyl-pyrrolidone and the like; and mixed solvents thereof. As the dehydrating agent, there are mentioned, for example, desiccants ordinarily used in dehydration of solvents, such as molecular sieve and the like; mineral acids such as hydrochloric acid, sulfuric acid, boron trifluoride and the like; and organic acids such as p-toluenesulfonic acid and the like. The reaction is conducted generally at about room temperature to 150° C., preferably at about room temperature to 100° C., and is complete generally in about 5 minutes to 10 hours. The amount of the compound of general formula (3) used is not particularly restricted but is generally at least equimolar to the compound of general formula (2), preferably 1-2 moles per mole of the compound (2). The amount of the dehydrating agent used is ordinarily a large excess when a desiccant is used, and is a catalysis amount when an acid is used. The thus obtained compound represented by the following general formula (A): ##STR6## (wherein R 1 , R 2 and R 3 are the same as defined above) is subjected to a reduction reaction without being isolated.
In the reduction reaction for the compound of general formula (A), various processes can be used. There can be used, for example, the same conditions as used in the catalytic hydrogenation (mentioned later) of compound of general formula (9). Preferably used, however, is a reduction process using a hydride reducing agent. This hydride reducing agent includes, for example, lithium aluminum hydride, sodium borohydride and diborane. It is used in an amount of at least 1 mole, preferably 1-10 moles per mole of the compound (2). This reduction reaction is conducted ordinarily in an appropriate solvent such as water, lower alcohol (e.g. methanol, ethanol or isopropanol), ether (e.g. tetrahydrofuran, diethyl ether or diglyme) or the like, generally at about -60 to 50° C., preferably -30° C. to room temperature for about 10 minutes to 5 hours. When lithium aluminum hydride or diborane is used as the reducing agent, it is preferable to use an anhydrous solvent such as diethyl ether, tetrahydrofuran, diglyme or the like. ##STR7## wherein R 1 , R 2 and R 3 are the same as defined above; X is a halogen atom; and R 4 and R 5 are independently a hydrogen atom or a lower alkyl group.
The reaction of the compound (4) with the compound (5) and the reaction of the compound (7) with the compound (10) are conducted generally in an appropriate inert solvent in the presence or absence of a basic compound. As to the inert solvent, there can be mentioned, for example, aromatic hydrocarbons such as benzene, toluene, xylene and the like; ethers such as tetrahydrofuran, dioxane, diethylene glycol dimethyl ether and the like; lower alcohols such as methanol, ethanol, isopropanol, butanol and the like; acetic acid; ethyl acetate; acetone; acetonitrile; dimethyl sulfoxide; dimethylformamide; hexamethylphosphoric triamide; and mixed solvents thereof. As to the basic compound, there can be mentioned, for example, carbonates such as sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate and the like; metal hydroxides such as sodium hydroxide, potassium hydroxide and the like; sodium hydride; potassium; sodium; sodium amide; metal alcholates such as sodium methylate, sodium ethylate and the like; and organic bases such as pyridine, N-ethyldiisopropylamine, dimethylaminopyridine, triethylamine, 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 1,4-diazabicyclo[2.2.2]octane (DABCO) and the like. The proportions of the compound (4) and the compound (5), or the proportions of the compound (7) and the compound (10) are not particularly restricted and can be appropriately selected in wide ranges; however, the latter is used desirably in an amount of at least about 1 mole, preferably about 1-5 moles per mole of the former. The reaction is conducted generally at about 0°-200° C., preferably at about 0°-170° C. and is complete generally in about 30 minutes to 30 hours. Incidentally, an alkali metal halide (e.g. sodium iodide or potassium iodide), etc. may be added to the reaction system.
The reaction of the compound (4) with the compound (6) is conducted in the absence of any solvent or in the presence of an appropriate solvent, in the presence of a reducing agent. The solvent can be exemplified by water; alcohols such as methanol., ethanol, isopropanol and the like; acetonitrile; formic acid; acetic acid; ethers such as dioxane, diethyl ether, diglyme, tetrahydrofuran and the like; aromatic hydrocarbons such as benzene, toluene, xylene and the like; and mixed solvents thereof. The reducing agent can be exemplified by formic acid; alkali metal salts of fatty acids, such as sodium formate and the like; hydride reducing agents such as sodium borohydride, sodium cyanoborohydride, lithium aluminum hydride and the like; and catalytic reducing agents such as palladium black, palladium-carbon, platinum oxide, platinum black, Raney nickel and the like.
When formic acid is used as the reducing agent, the reaction is desirably conducted generally at about room temperature to 200° C., preferably at about 50°-150° C. and is complete in about 1-10 hours. The desirable amount of formic acid used is a large excess over the compound (4).
When a hydride reducing agent is used, the reaction is desirably conducted generally at about -30° to 100° C., preferably at about 0°-70° C. and is complete in about 30 minutes to 15 hours. The desirable amount of the reducing agent used is generally about 1-20 moles, preferably about 1-6 moles per mole of the compound (4). When, in particular, lithium aluminum hydride is used as the hydride reducing agent, there is preferably used, as the solvent, an ether (e.g. diethyl ether, dioxane, tetrahydrofuran or diglyme) or an aromatic hydrocarbon (e.g. benzene, toluene or xylene).
When a catalytic reducing agent is used, the reaction is desirably conducted in a hydrogen atmosphere of generally about normal pressure to 20 atm., preferably about normal pressure to 10 atm. in the presence of a hydrogen donor such as formic acid, ammonium formate, cyclohexene, hydrazine hydrate or the like generally at about -30° to 100° C., preferably at about 0°-60° C., and is complete generally in about 1-12 hours. The desirable amount of the catalytic reducing agent used is generally about 0.1-40% by weight, preferably about 1-20% by weight based on the compound (4).
The desirable amount of the compound (6) used is generally at least equimolar, preferably equimolar to a large excess to the compound (4).
The reaction of the compound (7) with the compound (8) is carried out in accordance with an ordinary amide-bond formation reaction. The amide-bond formation reaction can be carried out by various known processes, for example, (a) a mixed acid anhydride process which comprises, for example, reacting the carboxylic acid (8) with an alkyl halocarboxylate to form a mixed acid anhydride and reacting the anhydride with the amine (7); (b) an active ester process which comprises, for example, converting the carboxylic acid (8) into an active ester such as p-nitrophenyl ester, N-hydroxysuccinimide ester, 1-hydroxybenzotriazole ester or the like and reacting the active ester with the amine (7); (c) a carbodiimide process which comprises subjecting the carboxylic acid (8) and the amine (7) to a condensation reaction in the presence of an activating agent such as dicyclohexylcarbodiimide, carbonyldiimidazole or the like; and (d) other processes. The other processes (d) include, for example, a process which comprises converting the carboxylic acid (8) into a carboxylic acid anhydride with a dehydrating agent such as acetic anhydride or the like and reacting the carboxylic acid anhydride with the amine (7); a process which comprises reacting an ester of the carboxylic acid (8) and a lower alcohol with the amine (7); and a process which comprises reacting a halide of the carboxylic acid (8), i.e. a carboxylic acid halide with the amine (7). There may also be employed, for example, a process which comprises activating the carboxylic acid (8) with a phosphorus compound such as triphenylphosphine, diethyl chlorophosphate or the like and reacting the resulting compound with the amine (7), and a process which comprises converting the carboxylic acid (8) into an N-carboxyaminoacid anhydride with phosgene, trichloromethyl chloroformate or the like and reacting the anhydride with the amine (7). There may further be employed, for example, a process which comprises activating the carboxylic acid (8) with an acetylene compound such as trimethylsilylethoxyacetylene or the like and reacting the activation product with the amine (7).
In the mixed acid anhydride process (a), the mixed acid anhydride used can be obtained by an ordinary Schotten-Baumann reaction. The anhydride is reacted with the amine (7) generally without being isolated, whereby a compound of general formula (9) can be produced. The Schotten-Baumann reaction is conducted in the presence of a basic compound. The basic compound is a compound conventionally used in the Schotten-Baumann reaction and includes, for example, organic bases such as triethylamine, trimethylamine, pyridine, N,N-dimethylaniline, N-methylmorpholine, 4-dimethylaminopyridine, DBN, DBU, DABCO and the like, and inorganic bases such as potassium carbonate, sodium carbonate, potassium hydrogencarbonate, sodium hydrogencarbonate and the like. The reaction is conducted at about -20° to 100° C., preferably at 0°-50° C. for about 5 minutes to 10 hours, preferably about 5 minutes to 2 hours. The reaction of the resulting mixed acid anhydride with the amine (7) is conducted at about -20° to 150° C. preferably at 10°-50° C. for about 5 minutes to 10 hours, preferably about 5 minutes to 5 hours. The mixed acid anhydride process (a) is conducted in an appropriate solvent or in the absence of any solvent. The solvent may be any solvent conventionally used in the mixed acid anhydride process, and can be exemplified by halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane and the like; aromatic hydrocarbons such as benzene, toluene, xylene and the like; ethers such as diethyl ether, dioxane, diisopropyl ether, tetrahydrofuran, dimethoxyethane and the like; esters such as methyl acetate, ethyl acetate and the like; and aprotic polar solvents such as 1,1,3,3-tetramethylurea, N,N-dimethylformamide, dimethyl sulfoxide, hexamethylphosphoric triamide and the like and mixed solvent thereof. The alkyl halocarboxylate used in the mixed acid anhydride process (a) can be exemplified by methyl chloroformate, methyl bromoformate, ethyl chloroformate, ethyl bromoformate and isobutyl chloroformate. The alkyl halocarboxylate is used in an amount of generally at least 1 mole, preferably about 1-1.5 moles per mole of the amine (7). The carboxylic acid (8) is used in an amount of generally at least 1 mole, preferably about 1-1.5 moles per mole of the amine (7).
The active ester process (b), when, for example, N-hydroxysuccinimide ester is used, is conducted in an appropriate solvent which does not adversely affect the reaction, in the presence or absence of a basic compound. Into the reaction system may be added a condensation agent such as dicyclohexylcarbodiimide, carbonyldiimidazole, 1-ethyl-3-(3'-dimethylaminopropyl)carbodiimide or the like. As the basic compound, there can be used any of the basic compounds used in the above-mentioned Schotten-Baumann reaction; and there may further be used alkali metal salts of carboxylic acids (e.g. sodium acetate, sodium benzoate, sodium formate, potassium acetate, lithium benzoate and cesium acetate), alkali metal halides (eg. potassium fluoride and cesium fluoride), etc. Specific examples of the solvent are halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane and the like; aromatic hydrocarbons such as benzene, toluene, xylene and the like; ethers such as diethyl ether, dioxane, tetrahydrofuran, dimethoxyethane and the like; esters such as methyl acetate, ethyl acetate and the like; aprotic polar solvents such as N,N-dimethylformamide, dimethyl sulfoxide, hexamethylphosphoric triamide and the like; and mixed solvents thereof. The reaction is conducted at 0°-150° C., preferably at 10°-100° C. and is complete in 5-30 hours. The desirable amount of the N-hydroxysuccinimide ester used is generally at least 1 mole, preferably 1-2 moles per mole of the amine (7).
A compound (9) can also be obtained by reacting the amine (7) with the carboxylic acid (8) in the presence of a phosphorus compound as condensation agent, such as triphenylphosphine, triphenylphosphine2,2'-dipyridyl disulfide, diethyl chlorophosphate, diphenylphosphinyl chloride, phenyl N-phenylphosphoramide chloridate, diethyl cyanophosphate, bis(2-oxo-3-oxazolidinyl)phosphinic chloride or the like. As the basic compound, there can widely be used known basic compounds, for example, the basic compounds used in the above-mentioned Schotten-Baumann reaction, sodium hydroxide and potassium hydroxide. The solvent used includes, for example, the solvents used in the mixed acid anhydride process (a), pyridine, acetone, acetonitrile and mixed solvents of two or more of said solvents. The reaction is conducted generally at about -20° to 150° C., preferably at about 0°-100° C. and is complete generally in 5 minutes to 30 hours. The desirable amounts of the condensation agent and the carboxylic acid (8) used are independently at least about 1 mole, preferably about 1-2 moles per mole of the amine (7).
A compound (9) can also be obtained by reacting the amine (7) with the carboxylic acid (8) in the presence of a condensation agent. The reaction is conducted in an appropriate solvent in the presence or absence of a catalyst. The solvent can be exemplified by halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride and the like; acetonitrile; and dimethylformamide. The catalyst can be exemplified by organic bases such as dimethylaminopyridine, 4-piperidinopyridine and the like; salts such as pyridinium tosylate and the like; camphorsulfonic acid; and mercury oxide. The condensation agent includes, for example, acetylene compounds such as trimethylsilylethoxyacetylene and the like. The condensation agent is desirably used in an amount of generally 1-10 moles, preferably 2-6 moles per mole of the amine (7). The carboxylic acid (8) is desirably used in an amount of generally at least about 1 mole, preferably about 1-2 moles per mole of the amine (7). The reaction is conducted generally at about 0°-150° C., preferably at about room temperature to 100° C. and is complete generally in about 1-10 hours.
When there is used one of the processes (d) which comprises reacting a halide of the carboxylic acid (8), i.e. a carboxylic acid halide with the amine (7), the reaction is conducted in an appropriate solvent in the presence of a dehydrohalogenating agent. An ordinary basic compound is used as the dehydrohalogenating agent. The basic compound can be selected widely from known basic compounds and includes, for example, the basic compounds used in the Schotten-Baumann reaction, sodium hydroxide, potassium hydroxide, sodium hydride and potassium hydride. The solvent includes the solvents used in the mixed acid anhydride process (a); alcohols such as methanol, ethanol, propanol, butanol, 3-methoxy-1-butanol, ethyl cellosolve, methyl cellosolve and the like; pyridine; acetone; acetonitrile; mixed solvents of two or more of said solvents; and so forth. The proportions of the amine (7) and the carboxylic acid halide are not particularly restricted and can be selected appropriately in wide ranges, but the latter is desirably used in an amount of generally at least about 1 mole, preferably about 1-5 moles per mole of the former. The reaction is conducted generally at about -20° to 180° C., preferably at about 0°-150° C. and is complete generally in about 5 minutes to 30 hours.
In the above, the carboxylic acid halide can be produced, for example, by reacting the carboxylic acid (8) with a halogenating agent in the presence or absence of a solvent. The solvent can be any solvent which does not adversely affect the reaction, and includes, for example, aromatic hydrocarbons such as benzene, toluene, xylene and the like; halogenated hydrocarbons such as chloroform, methylene chloride, carbon tetrachloride and the like; ethers such as dioxane, tetrahydrofuran, diethyl ether and the like; dimethylformamide; and dimethyl sulfoxide. The halogenating agent can be an ordinary halogenating agent capable of converting the hydroxyl group of carboxyl group into a halogen, and can be exemplified by thionyl chloride, phosphorus oxychloride, phosphorus oxybromide, phosphorus pentachloride and phosphorus pentabromide. The proportions of the carboxylic acid (8) and the halogenating agent used are not particularly restricted and can be selected appropriately; however, when the reaction is conducted in the absence of any solvent, the latter is used generally in large excess of the former and, when the reaction is used in a solvent, the latter is used in an amount of generally at least about 1 mole, preferably 2-4 moles per mole of the former. The reaction temperature and time are not particularly restricted, either, but are generally about room temperature to 100° C., preferably 50°-80° C. and about 30 minutes to 6 hours, respectively.
The reaction for converting the compound (9) into a compound (1) can be conducted by various processes. It can be conducted, for example, by (1) subjecting the compound (9) to catalytic hydrogenation in an appropriate solvent in the presence of a catalyst. The solvent includes, for example, water; acetic acid; alcohols such as methanol, ethanol, isopropanol and the like; hydrocarbons such as hexane, cyclohexane and the like; ethers such as diethylene glycol dimethyl ether, dioxane, tetrahydrofuran, diethyl ether and the like; esters such as ethyl acetate, methyl acetate and the like; aprotic polar solvents such as dimethylformamide and the like; and mixed solvents thereof. As the catalyst, there can be used, for example, palladium, palladium black, palladium-carbon, platinum, platinum oxide, copper chromite and Raney nickel. The desirable amount of the catalyst used is generally about 0.02-1 time the amount of the compound (9). The reaction temperature is generally about -20° to 100° C., preferably about 0°-70° C.; the desirable hydrogen pressure is generally 1-10 atm.; and the reaction is complete generally in about 0.5-20 hours.
In the reaction for converting the compound (9) into a compound (1), there is preferably used (2) a reduction process using a hydride reducing agent. The hydride reducing agent includes, for example, lithium aluminum hydride, sodium borohydride and diborane. It is used in an amount of generally at least 1 mole, preferably 1-10 moles per mole of the compound (9). The reduction reaction is conducted generally in an appropriate solvent such as water, lower alcohol (e.g. methanol, ethanol or isopropanol), ether (e.g. tetrahydrofuran, diethyl ether or diglyme), acetic acid or the like, generally at about 0°-200° C., preferably at 0-°170° C. for about 10 minutes to 10 hours. When lithium aluminum hydride or diborane is used as the reducing agent, it is preferable to use an anhydrous solvent such as diethyl ether, tetrahydrofuran, diglyme or the like. ##STR8## wherein R 1 , R 2 and R 3 are the same as defined above.
The reaction of the carboxylic acid compound (11) with the amine compound (3) can be conducted under the same conditions as in the reaction of the amine compound (7) with the carboxylic acid compound (8) in the Reaction formula-2. The desirable amount of the amine compound (3) used is determined per molar quantity of the carboxylic compound (11).
The reduction reaction for the compound (12) can be conducted under the same conditions as in the reduction reaction for the compound (9) in the Reaction formula-2. The compound (12) can be produced, for example, by a process shown by the following Reaction formula-4. ##STR9## wherein R 3 and X are the same as defined above; and R 6 and R 7 are each R 1 or --CH 2 R 2 (R 1 and R 2 are the same as defined above) with a proviso that when R 6 is R 1 , R 7 is --CH 2 R 2 and, when R 6 is --CH 2 R 2 , R 7 is R 1 .
The reaction of the compound (11) with the compound (13) is conducted under the same conditions as in the reaction of the compound (11) with the compound (3) in the Reaction formula-3. The reaction of the compound (14) with the compound (15) is conducted under the same conditions as in the reaction of the compound (4) with the compound (5) in the Reaction formula-2.
The starting material (4) or (7) in the Reaction formula-2 can be produced, for example, by a process shown by the following Reaction formula-5. ##STR10## wherein R 3 and R 6 are the same as defined above.
In the Reaction formula-5, a compound (16) wherein R 6 is R 1 , is the compound (7), and a compound (16) wherein R 6 is --CH 2 R 2 , is the compound (4). The reaction of the compound (2) with the compound (13) is conducted under the same conditions as in the reaction of the compound (2) with the compound (3) in the Reaction formula-1.
The starting material (2) in the Reaction formula-1 and the starting material (11) in the Reaction formula-3 or the Reaction formula-4 can be produced, for example, by a process shown by the following Reaction formula-6. ##STR11## wherein R 3 and X are the same as defined above.
The reaction of the compound (17) with the compound (19) and the reaction of the compound (18) with the compound (19) are each conducted under the same conditions as in the reaction of the compound (4) with the compound (5) in the Reaction formula-2.
Of the present compounds represented by general formula (1), those having a basic group can each form an acid addition salt easily by being reacted with a pharmacologically acceptable acid. The acid can be exemplified by inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid and the like, and organic acids such as oxalic acid, acetic acid, succinic acid, malonic acid, methanesulfonic acid, maleic acid, fumaric acid, malic acid, tartaric acid, citric acid, benzoic acid and the like.
Each of the intended compounds obtained by the above reaction formulas can be easily isolated and purified by ordinary separation means. The separation means can be exemplified by solvent extraction, dilution, recrystallization, column chromatography and preparative thin-layer chromatography.
Each of the compounds of general formula (1) is used generally in the form of ordinary pharmaceutical preparation. The pharmaceutical preparation is prepared by using diluents or excipients ordinarily used, such as filler, bulking agent, binder, humectant, disintegrator, surfactant, lubricant and the like. The pharmaceutical preparation can be prepared in various forms depending upon the purpose of remedy, and the typical forms include tablets, pills, a powder, a solution, a suspension, an emulsion, granules, capsules, suppositories, an injection (e.g. solution or suspension), etc. In preparing tablets, there can be used various carriers known in the field, exemplified by excipients such as lactose, white sugar, sodium chloride, glucose, urea, starch, calcium carbonate, kaolin, crystalline cellulose, silicic acid and the like; binders such as water, ethanol, propanol, simple syrup, lactose solution, starch solution, gelatin solution, carboxymethyl cellulose, shellac, methyl cellulose, potassium phosphate, polyvinylpyrrolidone and the like; disintegrators such as dry starch, sodium alginate, powdered agar, powdered laminarin, sodium hydrogencarbonate, calcium carbonate, polyoxyethylene sorbitan-fatty acid esters, sodium lauryl sulfate, stearic acid monoglyceride, starch, lactose and the like; disintegration inhibitors such as white sugar, stearin, cacao butter, hydrogenated oil and the like; absorption promoters such as quaternary ammonium salts, sodium lauryl sulfate and the like; humectants such as glycerine, starch and the like; adsorbents such as starch, lactose, kaolin, bentonite, colloidal silicic acid and the like; and lubricants such as refined talc, stearic acid salts, boric acid powder, polyethylene glycol and the like. The tablets can be prepared, as necessary, in the form of ordinary coated tablets, such as sugar-coated tablets, gelatin-coated tablets, enteric coated tablets or film-coated tablets, or in the form of double-layered tablets or multi-layered tablets. In preparing pills, there can be used various carriers known in the field, exemplified by excipients such as glucose, lactose, starch, cacao butter, hardened vegetable oils, kaolin, talc and the like; binders such as powdered acacia, powdered tragacanth, gelatin, ethanol and the like; and disintegrators such as laminarin, agar and the like. In preparing suppositories, there can be used various carriers known in the field, exemplified by a polyethylene glycol, cacao butter, a higher alcohol ester, gelatin and a semi-synthetic glyceride. In preparing an injection (solution, emulsion or suspension), the solution and suspension are sterilized and are preferably made isotonic to the blood. In preparing the solution, emulsion or suspension, there can be used all diluents conventionally used in the field, such as water, ethyl alcohol, propylene glycol, ethoxylated isostearyl alcohol, polyoxy-isostearyl alcohol and polyoxyethylene sorbitan-fatty acid esters. In this case, the pharmaceutical preparation may contain sodium chloride, glucose or glycerine in an amount sufficient to make the preparation isotonic, and may-further contain a solubilizing agent, a buffer solution, a soothing agent, etc. all ordinarily used. The pharmaceutical preparation may furthermore contain, as necessary, a coloring agent, a preservative, a perfume, a flavoring agent, a sweetening agent and other drugs.
The amount of the compound of general formula (1) or its salt according to the present invention to be contained in the pharmaceutical preparation is not particularly restricted and can be appropriately selected from a wide range, but the desirable amount is generally 1-70% by weight in the pharmaceutical preparation.
The method for administering the pharmaceutical preparation is not particularly restricted. It is decided depending upon the form of preparation, the age, distinction of sex and other conditions of patient, the disease condition of patient, etc. For example, tablets, pills, a solution, a suspension, an emulsion, granules or capsules are administered orally. An injection is intravenously administered singly or in admixture with an ordinary auxiliary solution of glucose, amino acids or the like, or, as necessary, is singly administered intramuscularly, intradermally, subcutaneously or intraperitoneally. Suppositories are administered intrarectally.
The dose of the pharmaceutical preparation is appropriately selected depending upon the administration method, the age, distinction of sex and other conditions of patient, the disease condition of patient, etc., but the desirable dose is generally about 0.2-200 mg per kg of body weight per day in terms of the amount of the active ingredient, i.e. the compound of general formula (1) or its salt.
Description is made hereinafter on Preparation Examples, Reference Examples, Examples and Results of Pharmacological Tests.
Preparation Example 1
______________________________________4-(4-Chlorobenzyloxy)-N-cyclopropyl- 5 mgmethyl-N-methylbenzylamineStarch 132 mgMagnesium stearate 18 mgLactose 45 mgTotal 200 mg______________________________________
Tablets each containing the above composition were produced by an ordinary method.
Preparation Example 2
______________________________________2-(4-Chlorobenzyloxy)-N-cyclopropyl- 150 mgmethyl-N-methylbenzylamineAvicel (trade mark, a product of ASAHI 40 gCHEMICAL INDUSTRY CO., LTD.)Corn starch 30 gMagnesium stearate 2 gHydroxypropyl methyl cellulose 10 gPolyethylene glycol 6000 3 gCastor oil 40 gMethanol 40 g______________________________________
The present invention compound, Avicel, corn starch and magnesium stearate were mixed and ground, and then made into tablets using a punch (R: 10 mm). The tablets were coated with a film coating agent consisting of hydroxypropyl methyl cellulose, polyethylene glycol 6000, castor oil and methanol, whereby film-coated tablets were produced.
Reference Example 1
To a solution of 1.2 g of 3-hydroxybenzaldehyde in 50 ml of N,N-dimethylformamide were added 2.4 g of 4-chlorobenzyl chloride and 2.1 g of potassium carbonate. The mixture was stirred at 60° C. for 3 hours. After cooling, the reaction mixture was treated with ethyl acetate-water. The resulting ethyl acetate layer was separated, washed with water, dried with anhydrous magnesium sulfate, and subjected to vacuum distillation to remove the solvent. The resulting residue was purified by silica gel column chromatography (eluant: n-hexane/ethyl acetate=102) to obtain 1.9 g of 3-(4-chlorobenzyloxy)benzaldehyde.
Colorless needles
1 H-NMR (CDCl 3 ) δ ppm: 5.10 (2H, s), 7.21-7.25 (1H, m), 7.38 (4H, s), 7.43-7.49 (3H, m), 9.98 (1H, s)
Reference Example 2
To a solution of 10 g of 4-hydroxybenzoic acid in 100 ml of N,N-dimethylformamide were added 29.1 g of 4-chlorobenzyl chloride and 25 g of potassium carbonate. The mixture was stirred at 60° C. for 3 hours. After cooling, the reaction mixture was treated with ethyl acetate-water. The resulting ethyl acetate layer was separated, washed with water, dried with anhydrous magnesium sulfate, and subjected to vacuum distillation to remove the solvent. The resulting residue was washed with n-hexane, then collected by filtration, and suspended in 50 ml of ethanol. To the suspension was added 100 ml of a 2N aqueous sodium hydroxide solution. The mixture was stirred at room temperature for 4 days and then neutralized with concentrated hydrochloric acid. The resulting crystals were collected by filtration and recrystallized from chloroform to obtain 16.7 g of 4-(4-chlorobenzyloxy)benzoic acid.
Colorless scales
1 H-NMR (DMSO-d 6 ) δ ppm: 5.14 (2H, s), 6.95 (2H, d, J=8.5 Hz), 7.47 (2H, d, J=11 Hz), 7.52 (2H, d, J=11 Hz), 7.87 (2H, d, J=8.5 Hz)
Reference Example 3
2-(4-Chlorobenzyloxy)benzoic acid was obtained in the same manner as in Reference Example 2 by using 2-hydroxybenzoic acid as a starting material.
Yellow prisms
1 H-NMR (CDCl 3 ) δ ppm: 5.26 (2H, s), 7.07-7.17 (2H, m), 7.39 (4H, s), 7.51-7.58 (1H, m), 8.16 (1H, dd, J=2.0 Hz, J=8.0 Hz)
Reference Example 4
The following compounds were obtained in the same manner as in Reference Example 1 by using 3-hydroxybenzaldehyde as a starting material.
3-(2-Chlorobenzyloxy)benzaldehyde
Colorless granules
1 H-NMR (CDCl 3 ) δ ppm: 5.21 (2H, s), 7.24-7.31 (3H, m), 7.39-7.57 (5H, m), 9.98 (1H, s)
3-(3-Chlorobenzyloxy)benzaldehyde
Colorless oil
1 H-NMR (CDCl 3 ) δ ppm: 5.10 (2H, s), 7.22-7.33 (4H, m), 7.43-7.52 (4H, m), 9.98 (1H, s)
3-(4-Fluorobenzyloxy)benzaldehyde
Pink powder
1 H-NMR (CDCl 3 ) δ ppm: 5.08 (2H, s), 7.09 (2H, dd, J=8.5 Hz, J=8.5 Hz), 7.22-7.26 (1H, m), 7.39-7.50 (5H, m), 9.98 (1H, s)
3-(4-Bromobenzyloxy)benzaldehyde
White powder
1 H-NMR (CDCl 3 ) δ ppm: 5.07 (2H, s), 7.20-7.26 (1H, m), 7.30-7.34 (2H, m), 7.42-7.55 (5H, m), 9.97 (1H, s)
Reference Example 5
A solution of 62 g of 3-(4-chlorobenzyloxy)-benzaldehyde and 20 g of cyclopropylmethylamine in 750 ml of methanol was stirred at room temperature for 15 minutes. Thereto was slowly added 12 g of sodium borohydride with ice-cooling. The resulting mixture was stirred at the same temperature for 1 hour. The reaction mixture was dissolved in 1 liter of chloroform. The solution was washed with water, dried with anhydrous magnesium sulfate, and subjected to vacuum distillation to remove the solvent, whereby 81 g of 3-(4-chlorobenzyloxy)-N-cyclopropylmethylbenzylamine was obtained.
Yellow oil
1 H-NMR (CDCl 3 ) δ ppm: 0.06-0.12 (2H, m), 0.44-0.51 (2H, m), 0.92-1.00 (1H, m), 1.55 (1H, m), 2.47 (2H, d, J=7 Hz), 3.79 (2H, s), 5.04 (2H, s), 6.81-6.96 (3H, m), 7.24 (1H, dd, J=8 Hz, J=8 Hz), 7.36 (4H, s)
Reference Example 6
3-(4-Chlorobenzyloxy)-N-methylbenzylamine was obtained in the same manner as in Reference Example 5 by using suitable starting materials.
Yellow oil .sup. 1H-NMR (CDCl 3 ) δ ppm: 1.40 (1H, bs), 2.45 (3H, s), 3.73 (2H, s), 5.03 (2H, s), 6.82-6.95 (3H, m), 7.24 (1H, dd, J=8.0 Hz, J=8.0 Hz), 7.36 (4H, s)
Reference Example 7
To a solution of 2.1 g of 3-(4-chlorobenzyloxy)-N-methylbenzylamine and 3.4 ml of triethylamnine in 50 ml of dichloromethane was dropwise added 1.0 ml of cyclobutanecarbonyl chloride with ice-cooling. The mixture was stirred at room temperature for 1 hour. The reaction mixture was washed with water, dried with anhydrous magnesium sulfate, and subjected to vacuum distillation to remove the solvent, whereby 3.1 g of 3-(4-chlorobenzyloxy)-N-cyclobutonecarbonyl-N-methylbenzylamine was obtained.
Yellow oil
1 H-NMR (CDCl 3 ) δ ppm: 1.81-2.53 (6H, m), 2.80, 2.90 (total 3H, s), 3.20-3.48 (1H, m), 4.40, 4.54 (total 2H, s), 5.01 (2H, s), 6.70-6.93 (3H, m), 7.19-7.33 (1H, m), 7.35 (4H, s)
Reference Example 8
In 80 ml of thionyl chloride was dissolved 5 g of 4-(4-chlorobenzyloxy)benzoic acid. The solution was refluxed with heating, for 1 hour and then subjected to vacuum distillation to remove thionyl chloride. The resulting residue was dissolved in 30 ml of dichloromethane. The solution was dropwise added, with ice-cooling, to a solution of 2.2 g of cyclopropylmethylamine and 10 ml of triethylamine in 100 ml of dichloromethane. The mixture was stirred at room temperature for 1 hour. The reaction mixture was washed with 2N hydochloric acid and water, dried with anhydrous magnesium sulfate, and subjected to distillation to remove the solvent, whereby 4.2 g of 4-(4-chlorobenzyloxy)-N-cyclopropylmethylbenzamide was obtained.
White powder
1 H-NMR (CDCl 3 ) δ ppm: 0.23-0.30 (2H, m), 0.51-0.59 (2H, m), 1.00-1.15 (1H, m), 3.30 (2H, dd, J=5.5 Hz, J=7.0 Hz), 5.07 (2H, s), 6.09-6.21 (1H, m), 6.95-7.00 (2H, m), 7.36 (4H, s), 7.72-7.77 (2H, m)
Reference Example 9
2-(4-Chlorobenzyloxy)-N-cyclopropylmethylbenzamide was obtained in the same manner as in Reference Example 8 by using 2-(4-chlorobenzyloxy)benzoic acid as a starting material.
White powder
1 H-NMR (CDCl 3 ) δ ppm: 0.02-0.08 (2H, m), 0.29-0.37 (2H, m), 0.77-0.85 (1H, m), 3.22 (2H, dd, J=5.0 Hz, J=7.0 Hz), 5.14 (2H, s), 7.03-7.15 (2H, m), 7.38-7.48 (1H, m), 7.41 (4H, s), 7.72-7.98 (1H, m), 8.24 (1H, dd, J=2.0 Hz, J=8.0 Hz)
Reference Example 10
In 30 ml of N,N-dimethylformamide was dissolved 1.5 g of 4-(4-chlorobenzyloxy)-N-cyclopropylmethylbenzamide. To the solution was added 0.25 g of sodium hydride. The mixture was stirred at room temperature for 30 minutes and then at 60° C. for 30 minutes. The reaction mixture was ice-cooled, and 0.5 ml of methyl iodide was added thereto. The mixture was stirred overnight at room temperature. The reaction mixture was treated with ethyl acetate-water. The resulting ethyl acetate layer was separated, washed with water, dried with anhydrous magnesium sulfate, and subjected to distillation to remove the solvent. The resulting residue was purified by column chromatography (eluant: dichloromethane/acetone=50/1) to obtain 1.4 g of 4-(4-chlorobenzyloxy)-N-cyclopropylmethyl-N-methylbenzamide.
Colorless oil
1 H-NMR (CDCl 3 ) δ ppm: 0.00-0.40 (2H, m), 0.51-0.63 (2H, m), 0.88-1.11 (1H, m), 2.95-3.50 (5H, m), 5.05 (2H, s), 6.93-6.97 (2H, m), 7.26-7.40 (2H, m), 7.37 (4H, s)
Reference Example 11
2-(4-Chlorobenzyloxy)-N-cyclopropylmethyl-N-methylbenzamide was obtained in the same manner as in Reference Example 10 by using, as a starting material, 2-(4-chlorobenzyloxy)-N-cyclopropylmethylbenzamide.
Light yellow oil
1 H-NMR (CDCl 3 ) δ ppm: 0.05-0.10, 0.23-0.37, 0.37-0.55 (total 4H, m), 0.75-0.92, 0.92-1.08 (total 1H, m) , 2.88-3.25 (5H, m), 5.07-5.14 (2H, m), 6.89-7.14 (2H, m), 7.25-7.45 (6H, m)
Reference Example 12
The following compounds were obtained in the same manner as in Reference Example 5 by using suitable starting materials.
3-(2-Chlorobenzyloxy)-N-cyclopropylmethylbenzylamine
Colorless oil
1 H-NMR (CDCl 3 ) δ ppm: 0.07-0.13 (2H, m), 0.44-0.51 (2H, m), 0.92-1.10 (1H, m), 1.35-1.61 (1H, m), 2.48 (2H, d, J=7.0 Hz), 3.80 (2H, s), 5.17 (2H, s), 6.85-6.99 (3H, m), 7.25-7.32 (3H, m), 7.38-7.42 (1H, m), 7.55-7.59 (1H, m)
(3-Chlorobenzyloxy)-N-cyclopropylmethylbenzylamine
Colorless oil
1 H-NMR (CDCl 3 ) δ ppm: 0.07-0.12 (2H, m), 0.44-0.51 (2H, m), 0.50-1.08 (1H, m), 1.35-1.52 (1H, m), 2.48 (2H, d, J=7.0 Hz), 3.80 (2H, s), 5.04 (2H, s), 6.82-6.97 (3H,m), 7.21-7.30 (4H, m), 7.44-7.45 (1H, m)
3-(4-Fluorobenzyloxy)-N-cyclopropylmethylbenzylamine
Colorless oil 1 H-NMR (CDCl 3 ) δ ppm: 0.07-0.13 (2H, m), 0.44-0.51 (2H, m), 0.92-1.08 (1H, m), 1.40-1.70 (1H, m), 2.47 (2H, d, J=7.0 Hz), 3.80 (2H, s), 5.03 (2H, s), 6.83-6.97 (3H, m), 7.04-7.10 (2H, m), 7.26 (1H, dd, J=8.0 Hz, J=8.0 Hz), 7.38-7.44 (2H, m)
3-(4-Bromobenzyloxy ) -N-cyclopropylmethylbenzylamine
Colorless oil
1 H-NMR (CDCl 3 ) δ ppm: 0.06-0.12 (2H, m), 0.44-0.51 (2H, m), 0.91-1.06 (1H, m), 1.34-1.60 (1H, m), 2.47 (2H, d, J=7.0 Hz), 3.79 (2H, s), 5.02 (2H, s), 6.81-6.95 (3H, m), 7.20-7.33 (3H, m), 7.49-7.52 (2H, m)
Reference Example 13
The following compounds were obtained in the same manner as in Reference Example 8 by using suitable starting materials.
3-(4-Chlorobenzyloxy)-N-cyclohexylmethylbenzamide
White powder
1 H-NMR (CDCl 3 ) δ ppm: 0.95-1.11 (2H, m), 1.11-1.36 (3H, m), 1.56-1.90 (6H, m), 3.29 (2H, dd, J=6.5 Hz, J=6.5 Hz), 5.06 (2H, s), 6.18-6.29 (1H, m), 7.04-7.09 (1H, m), 7.26-7.43 (3H, m), 7.36 (4H, s)
3-(4-Chlorobenzyloxy)-N-cyclopropylmethyl-N-propylbenzamide
White powder
1 H-NMR (CDCl 3 ) δ ppm: 0.01-1.82 (10H, m), 3.00-3.63 (4H, m), 5.05 (2H, s), 6.91-6.99 (3H, m), 7.30 (1H, dd, J=8.0 Hz, J=8.0 Hz), 7.35 (4H, s)
Reference Example 14
3-(4-Chlorobenzyloxy)-N-cyclohexylmethyl-N-methylbenzamide was obtained in the same manner as in Reference Example 10 by using, as a starting material,
3-(4-chlorobenzyloxy)-N-cyclohexylmethylbenzamide.
Colorless oil
1 H-NMR (CDCl 3 ) δ ppm: 0.55-0.72, 0.95-1.37, 1.52-1.85 (total 11H, m), 2.89, 3.04 (total 3H, s), 3.06, 3.37 (total 2H, s), 5.05 (2H, s), 6.92-6.99 (3H, m), 7.30 (1H, dd, J=8.5 Hz, J=8.5 Hz), 7.36 (4H, s)
EXAMPLE 1
In a mixture of 150 ml of formic acid and 150 ml of 37% formaldehyde was dissolved 80 g of 3-(4-chlorobenzyloxy)-N-cyclopropylmethylbenzylamine. The solution was refluxed with heating, for 3 hours. The reaction mixture was cooled to room temperature, and 150 ml of concentrated hydrochloric acid was added thereto. The mixture was subjected to vacuum distillation to remove the solvent. The resulting residue was treated with chloroform-aqueous sodium hydroxide solution. The resulting chloroform layer was separated, washed with water, dried with anhydrous sodium sulfate, and subjected to vacuum distillation to remove the solvent, whereby 86 g of 3-(4-chlorobenzyloxy)-N-cyclopropylmethyl-N-methylbenzylamine was obtained as a brown oil.
Of 86 g, 3 g was converted into a hydrochloride. The hydrochloride was recrystallized from ethyl acetate to obtain 2.1 g of 3-(4-chlorobenzyloxy)-N-cyclopropylmethyl-N-methylbenzylamine hydrochloride.
Colorless needles
Melting point: 119.0°-121.0° C.
The compounds of Examples 2-10 shown in Table 1 were obtained in the same manner as in Example 1 by using suitable starting materials.
TABLE 1__________________________________________________________________________ ##STR12## ##STR13## ##STR14## ##STR15## ##STR16## ##STR17## ##STR18##__________________________________________________________________________ 2 CH.sub.3 ##STR19## ##STR20## White powder (Ethanol) 154.0-154.5 (Oxalate) 3 CH.sub.3 ##STR21## ##STR22## Slightly blue powder (Etanol- diethyl ether) 125.0-126.5 (Oxalate) 4 CH.sub.3 ##STR23## ##STR24## White powder (Ethanol) 102.5-103.0 (Maleate) 5 CH.sub.3 ##STR25## ##STR26## White powder (Ethanol) 125.0-126.0 (Oxalate) 6 CH.sub.3 ##STR27## ##STR28## White powder (Ethanol) 140.5-141.0 (Oxalate) 7 CH.sub.3 ##STR29## ##STR30## Colorless granules (Ethanol) 138.0-139.0 (Oxalate) 8 CH.sub.3 ##STR31## ##STR32## White powder (Ethanol) 129.0-141.0 (Oxalate) 9 CH.sub.3 ##STR33## ##STR34## White powder (Ethanol) 187.0-187.5 (Oxalate)10n-C.sub.3 H.sub.7 ##STR35## ##STR36## White powder (Ethanol- diethyl ether) 78.0-82.5 (Oxalate)__________________________________________________________________________
EXAMPLE 11
0.5 g of lithium aluminum hydride was added to a solution of 1.4 g of 4-(4-chlorobenzyloxy)-N-cyclopropylmethyl-N-methylbenzamide in 50 ml of tetrahydrofuran. The mixture was refluxed with heating, for 3 hours. The reaction mixture was cooled, and 2 ml of water was added thereto. The mixture was stirred at room temperature for 14 hours. The reaction mixture was filtered and the filtrate was treated with water-diethyl ether. The resulting diethyl ether layer was separated, washed with water, dried with anhydrous magnesium sulfate, and subjected to vacuum distillation to remove the solvent. The resulting residue was converted into an oxalate. The oxalate was recrystallized from ethanol to obtain 1.3 g of 4-(4-chlorobenzyloxy)-N-cyclopropylmethyl-N-methylbenzylamine oxalate.
White powder
Melting point: 154.0°-154.5° C.
The compounds of Examples 1 and 3-10 were obtained in the same manner as in Example 11 by using suitable starting materials.
EXAMPLE 12
To a solution of 62 g of 4-(4-chlorobenzyloxy)benzaldehyde and 24 g of N-cyclopropylmethyl-N-methylamine in 750 ml of methanol was slowly added 12 g of sodium borohydride with ice-cooling. The mixture was stirred at the same temperature for 1 hour. The reaction mixture was dissolved in 1 liter of chloroform. The solution was washed with water, dried with anhydrous magnesium sulfate, and subjected to vacuum distillation to remove the solvent. The resulting residue was converted into an oxalate. The oxalate was recrystallized from ethanol to obtain 84 g of 4-(4-chlorobenzyloxy)-N-cyclopropylmethyl-N-methylbenzylamine oxalate.
White powder
Melting point: 154.0°-154.5° C.
The compounds of Examples 1 and 3-10 were obtained in the same manner as in Example 12 by using suitable starting materials.
EXAMPLE 13
0.92 g of lithium aluminum hydride was added to a solution of 2.8 g of 3-(4-chlorobenzyloxy)-N-cyclobutanecarbonyl-N-methylbenzylamine in 50 ml of tetrahydrofuran. The mixture was refluxed with heating, for 3 hours. The reaction mixture was cooled, and 2 ml of water was added thereto. The mixture was stirred for 14 hours and then filtered. The filtrate was treated with water-diethyl ether. The resulting diethyl ether layer was separated, washed with water, dried with anhydrous magnesium sulfate, and subjected to vacuum distillation to remove the solvent. The residue was converted into a maleate. The maleate was recrystallized from ethanol to obtain 1.9 g of 3-(4-chlorobenzyloxy)-N-cyclobutylmethyl-N-methylbenzylamine maleate.
White powder
Melting point: 102.5°-103.0° C.
The compounds of Examples 1-3 and 5-10 were obtained in the same manner as in Example 13 by using suitable starting materials.
Pharmacological Tests
(1) Forced swimming test
This test was conducted by modifying the test methods described in Nature, Vol. 266, pp. 730-732 (1977) and European Journal of Pharmacology, Vol. 47, pp. 379-391 (1978). That is, a tap water (temp.: about 25° C.) was fed into a clindrical water bath (inside diameter: 29.5 cm, height: 25 cm) made of a transparent acrylic resin, to a water depth of 11.3 cm. Male mice of 7-8 week-age each weighing 30-35 g were forced to swim therein for 6 minutes, and the amount of swimming was measured. The measurement of amount of swimming was automatically made by the use of an infrared beam and a sensor capable of detecting the beam, and the number of counting was used as a yardstick indicating the depressive state of mouse. A larger number means a higher antidepressive activity of test compound used.
Each mouse was fasted for 16-18 hours before swimming and received oral administration of a test compound and a solvent 1 hour before the start of the test. The solvent was a physiological saline solution containing 5% of acasia, and the test compound was used by suspensing or dissolving in the solvent. Each mouse of control group received only the solvent, i.e. the physiological saline solution containing 5% of acasia.
The results are shown in Table 2. In Table 2, the values of swimming amount (%) are those when the value of control group was taken as 100%.
TABLE 2______________________________________ Amount Amount of administered swimmingTest compound (mg/kg) (%)______________________________________Example 1 compound 1 120Example 2 compound 3 110Example 3 compound 30 118______________________________________
(2) Elevated plus-maze test
This test was conducted in accordance with the test methods described in Pharmacology Biochemistry & Behavior, Vol. 24, pp. 525-529 (1986) and Psychopharmacology, Vol. 92, pp. 180-185 (1987). There was used, as the test apparatus, an acrylic resin-made maze consisting of a platform (5×5 cm), two open arms (each 5×5 cm and having no wall surrounding the arms) and two closed arms (each 25×5 cm and surrounded, at the three sides, by a transparent acrylic resin-made wall 15 cm high), wherein the two open arms extended from the two opposite sides of the platform and the two closed arms extended from the remaining two opposite sidss of the platform (the two open arms and the two closed arms formed a cross shape via the platform). The platform, open arms and closed arms of the maze were held at a height of 38 cm from the floor of a room in which the maze was placed. On the platform of the maze was placed a male mouse of 4-5 week-age weighing 20-24 g which had been fasted for 16-18 hours, with the face being directed to either of the open arms. For 5 minutes from that timing, the movement of the mouse on the maze was observed to measure the times of entry into open arms and the times of entry into closed arms. There was used, as the yardstick of anti-anxiety activity of test compound, there was used "frequency of entry into open arms" which is defined as follows.
Frequency (%) of entry into open arms=(times of entry into open arms)-(times of entry into open arms+times of entry into closed arms)×100
A larger frequency means a higher anti-anxiety activity of test compound.
Each test compound was suspended or dissolved in a physiological saline solution containing 5% of acasia and orally administered to each mouse 1 hour before the mouse was placed on te maze. Only the physiological saline solution was administered to each mouse of control group.
The results are shown in Table 3. In Table 3, the values of frequency (%) are those when the value of control group was taken as 100%.
TABLE 3______________________________________ Amount administered FrequencyTest compound (mg/kg) (%)______________________________________Example 1 compound 1 262Example 2 compound 3 175Example 3 compound 3 128______________________________________
(3) Evaluation of effect for ameliorating disorder of consciousness, in a coma forcibly caused by head trauma
This test was conducted in accordance with the test methods described in Journal of Japan Accident Medical Association, Vol. 25, p. 202 (1977) and Journal of Clinical and Experimental Medicine (IGAKU NO AYUMI), Vol. 102, pp. 867-869 (1977). That is, male mice of 4-5 week-age each weighing 20-29 g were fasted for 18-20 hours; then, the head of each mouse was fixed to a foamed polystyrol-made pillow; an acrylic resin-made cylindrical bar was dropped, along a transparrent plastic tube, onto the vertex cranii of each mouse to give an impact to the mouse. The resulting disturbance of consciousness in mouse was examined by measuring the following two items: a time from the coma after impact to recovery of righting reflection (this time is referred to as RR time) and a time for said coma to recovery of spontaneous motility (this time is referred to as SM time). A test compound was suspended or dissolved in a physiological saline solution containing 5% of acasia and then orally administered to each mouse 1 hour before the mouse was subjected to anesthesia loading. Only the physiological saline solution containing 5% of acasia was administered to the mice of control group. The effect for ameliorating disturbance of consciousness, of each test compound was evaluated by a ratio (%) of RR or SM time of test compound-administered mice to RR or SM time of control group mice. Each of the present compounds tested showed a significant effect for ameliorating disturbance of consciousness.
(4) Test for amount of mouse's movement under controlled conditions
(a) Test animals
ddy-Strain male mice of 7-8 week-age each weighing 30-35 g.
(b) Test apparatus
A transparent acrylic resin-made test box of 30×30×29 cm having a grid floor; a photoelectric tester for measuring the amount of mouse's movement; and a shock generator for imparting an electrical shock to each mouse.
(c) Test procedure
On the first day, mice were placed in the above test apparatus and received an electrical shock (AC 160 V×3 A, 200 mse, 0.1 Hz) from the floor grid for 6 minutes. On the second day, the mice were returned to the same apparatus (but received no electrical shock) and measured for the amount of movement by using the above photoelectric tester (these mice were a condition-controlled group). The same procedure was applied to the mice of control group except that they received no electrical shock on the first day.
Each test compound was suspended in a physiological saline solution containing 5% of acasia, or dissolved in a physiological saline solution. The suspension or solution was orally administered to each mouse on the second day 30 minutes to 1 hour before the measurement of amount of movement. The parameter of the condition-controlled group was compared with that of the solvent alone-administered group (control group).
In this test, "parameter" is the amount of movement (the number of counting by the photoelectric tester) on the second day.
In the above test, the electrically-shocked mice, when returned to the same site, remember the shock and generate a stress; and this stress substantially reduce the amount of their movement. The present compounds tested were effective in recovering the amount of movement.
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A benzylamine derivative or salt thereof having antidepressant and antianxiety activities having the general formula: ##STR1## wherein R 1 is a lower alkyl group;
R 2 is a cycloalkyl group; and
R 3 is a halogen atom;
or salt thereof.
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INCORPORATION BY REFERENCE
[0001] Priority is claimed med to Japanese Patent Application No. 2015-208613, filed Oct. 23, 2015, the entire content which is incorporated herein by reference.
BACKGROUND
[0002] Technical Field
[0003] The present invention in particular embodiments relates to valve structures in valved nonlubricated linear compressors, and to nonlubricated linear compressors having the valve structures. In addition, the present invention in particular embodiments relates to cryogenic refrigerators having the nonlubricated linear compressors.
[0004] Description of Related Art.
[0005] Attempts at applying nonlubricated linear compressors to cryogenic refrigerators have been proposed.
SUMMARY
[0006] One embodiment of the present invention affords a valve structure for a valved nonlubricated linear compressor. The valve structure comprises: a valve seat part including a valve hole portion having a valve hole connecting a first gas chamber to a second gas chamber, and a valve-body supporting wail part extending laterally from the valve hole portion; an elastic valve-body member furnished with a first elastic platelike section disposed paralleling the valve hole portion such as to cover the valve hole, and a second elastic platelike section extending from the first elastic platelike section and paralleling the valve-body supporting wall part, wherein the first elastic platelike section is elastically deformable against the second elastic platelike section under pressure differential between the first gas chamber and the second gas chamber such as to uncover the valve hole; and an elastic pressing member arranged paralleling the second elastic platelike section such as to elastically deform together with the elastic valve-body member, the elastic pressing member being of planar form determined such as to expose the first elastic platelike section.
[0007] Another embodiment of the present invention affords a nonlubricated linear compressor including a valve structure as set forth above.
[0008] Still another embodiment of the present invention affords a cryocooler including the just-mentioned nonlubricated linear compressor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic view showing a cryocooler according to an embodiment of the present invention.
[0010] FIG. 2 is a sectional view schematically showing a linear compressor shown in FIG. 1 .
[0011] FIG. 3 is a sectional view schematical showing a valve structure of a valved nonlubricated linear compressor according to an embodiment of the present invention.
[0012] FIG. 4 is a plan view schematically showing an elastic valve body member shown in FIG. 3 .
[0013] FIG. 5 is a plan view schematically showing an elastic pressing member shown in FIG. 3 .
[0014] FIG. 6 is a top view schematically showing the valve structure shown in FIG. 3 .
[0015] FIG. 7 is a sectional view schematically showing a portion of a reed valve having a stopper.
[0016] FIG. 8 is a sectional view schematically showing a valve structure of a valved nonlubricated linear compressor according to another embodiment of the present invention.
[0017] FIG. 9 is a sectional view schematically showing a valve structure of a valved nonlubricated linear compressor according to still another embodiment of the present invention.
DETAILED DESCRIPTION
[0018] A nonlubricated linear compressor includes a valve therein. A stopper which restricts a movement, amount of a valve body maybe provided in the valve. However, if the movement amount of the valve body is restricted, since a flow rate of gas flowing through the valve decreases, the flow rate of gas which is discharged from a linear compressor also decreases. In addition, noise may occur due to collision of the valve body with respect to the stopper. In this way, there is room for improvement for the nonlubricated linear compressor including the valve having a stopper.
[0019] It is desirable to provide an improved valve structure, a valved nonlubricated linear compressor having the valve structure, and a cryocooler having the nonlubricated linear compressor.
[0020] In addition, arbitrary combinations of the above-described components, or components or expression of the present invention may be replaced by each other in methods, devices, systems, or the like, and these replacements are also included in aspects of the present invention.
[0021] According to the present invention, it is possible to provide an improved valve structure, a valved nonlubricated linear compressor having the valve structure, and a cryocooler having the valved nonlubricated linear compressor.
[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in descriptions thereof, the same reference numerals are assigned to the same elements, and overlapping descriptions thereof are omitted. In addition, configurations described below are exemplified, and do not limit the scope of the present invention.
[0023] FIG. 1 is a schematic view showing a cryocooler 100 according to an embodiment of the present invention. The cryocooler 100 includes a linear compressor 10 and an expander 102 . For example, the expander 102 is a Gifford McMahon type expander, and in this case, the cryocooler 100 is a Gifford McMahon type cryocooler.
[0024] A discharge port of the linear compressor 10 is connected to the expander 102 through a high-pressure pipe 104 . Moreover, a suction port of the linear compressor 10 is connected to the expander 102 through a low-pressure pipe 106 . A high-pressure working gas 36 is supplied from the linear compressor 10 to the expander 102 through the high-pressure pipe 104 . The high-pressure working gas 36 is adiabatically expanded in the expander 102 , and thus, the expander 102 generates coldness. A low-pressure working gas 34 is recovered front the expander 102 to the linear compressor 10 through the low-pressure pipe 106 . The linear compressor 10 compresses the low-pressure working gas 34 and supplies the compressed gas as the high-pressure working gas 36 to the expander 102 again. For example, the working gas is a helium gas.
[0025] FIG. 2 is a sectional view schematically showing the linear compressor 10 shown in FIG. 1 . The linear compressor 10 includes a compressor case 12 , a compressor container 14 , a piston 16 , a cylinder 18 , a linear actuator 20 , and a leaf spring unit 22 . In the linear compressor 10 , one piston 16 , and one cylinder 18 which accommodates the piston 16 are provided. The linear compressor 10 is configured of a nonlubricated linear compressor (may be referred to as an linear compressor) in which oil is not used so as to lubricate a movable element.
[0026] The compressor case 12 accommodates the compressor container 14 . Dynamic vibration absorbers 24 for preventing vibrations of the compressor container 14 from being transmitted to the outside or decreasing the vibrations are provided between the compressor case 12 and the compressor container 14 . The compressor case 12 may be a cover member which covers the dynamic vibration absorbers 24 .
[0027] The compressor container 14 is a pressure container which is configured so as to airtightly hold a working gas in the linear compressor 10 . The compressor container 14 accommodates the piston. 16 , a cylinder 18 , the linear actuator 20 , and the leaf spring unit 22 .
[0028] The compressor container 14 includes a high-pressure chamber 26 and a low-pressure chamber 28 of a working gas therein. A discharge pipe 30 is connected to the high-pressure chamber 26 , and a suction pipe 32 is connected to the low-pressure chamber 28 . The discharge pipe 30 penetrates the compressor case 12 and the compressor container 14 , and connects the high-pressure pipe 32 penetrates the compressor case 12 and the compressor container 14 , and connects the low-pressure chamber 28 to the outside of the linear compressor 10 . Accordingly, the low-pressure working gas 34 is recovered from the outside of the linear compressor 10 to the low-pressure chamber 28 through the suction pipe 32 . In addition, the high-pressure working gas 36 is supplied from the high-pressure chamber 26 to the outside of the linear compressor 10 through the discharge pipe 30 .
[0029] In addition, with the compressor container 14 or instead of the compressor container 14 , the compressor case 12 may be configured as a pressure container which airtightly holds the working gas in the linear compressor 10 .
[0030] The piston 16 is a movable body which partitions the inside of the compressor container 14 into the high-pressure chamber 26 and the low-pressure chamber 28 . The high-pressure chamber 26 includes a pressurization chamber 38 and a discharge chamber 40 . The pressurization chamber 38 is formed between the piston 16 and the cylinder 18 . The discharge chamber 40 is formed inside the cylinder 18 . The discharge pipe 30 is connected to the discharge chamber 40 .
[0031] The linear compressor 10 is configured of a valved linear compressor. An intake valve 42 for supplying the low-pressure working gas 34 from the low-pressure chamber 28 to the high-pressure chamber 26 is provided in the piston 16 . The intake valve 42 is opened and closed by a pressure difference between the high-pressure chamber 26 and the low-pressure chamber 28 . The intake valve 42 is opened when the pressure difference exceeds a predetermined threshold value, and is closed when the pressure difference is dower than the threshold value. A discharge valve 14 for discharging the high-pressure working gas 36 from the pressurization chamber 38 to the discharge chamber 40 is provided in the cylinder 18 . The discharge valve 44 is opened and closed by a pressure difference between the pressurization chamber 38 and the discharge chamber 40 . The discharge valve 44 is opened when the pressure difference exceeds a predetermined threshold value, and is closed when the pressure difference is lower than the threshold value. For example, the intake valve 42 and the discharge valve 44 are reed valve type valves.
[0032] The piston 16 is a hollow cylindrical member which extends in an axial direction (a vertical direction in FIG. 2 ) The piston. 16 includes a piston tip portion 46 which faces the pressurization chamber 38 , and a piston main body portion 48 which extends from the piston tip portion 46 toward the side opposite to the pressurization chamber 38 in the axial direction.
[0033] A first piston recessed portion 50 is formed in the piston tip portion 46 , and a second piston recessed portion 52 is formed in the piston main body portion 48 . The first piston recessed portion 50 is a hollow portion of the piston tip portion 46 , piston recessed portion 52 is a hollow portion of the piston main body portion 48 , and forms a portion of the low-pressure chamber 28 .
[0034] A piston partition portion 54 is provided between the piston tip portion 46 and the piston main body portion 48 . The piston partition portion 54 is a wall which partitions the piston into the first piston recessed portion 50 and the second piston recessed portion 52 . A piston communication hole 56 is formed at the center of the piston partition portion 54 . The piston communication hole 56 communicates with the first piston recessed portion 50 and the second piston recessed portion 52 . The intake valve 42 is accommodated in the first piston recessed portion 50 . The intake valve 42 is configured so as to open and close the piston communication hole 56 by a pressure difference between the first piston recessed portion 50 and the second piston recessed portion 52 .
[0035] The piston 16 is supported to the compressor container 14 in a reciprocation-enable manner (for example, a vibration-enable manner) in the axial direction by the leaf spring unit 22 . A radial inner portion of the leaf spring unit 22 is attached to the base end portion of the piston main body portion 48 so as to circumferentially surround the piston 16 . A radial outer portion of the leaf spring unit 22 is attached to the compressor container 14 .
[0036] Moreover, the piston 16 includes a piston drive portion 49 which is driven by the linear actuator 20 . The piston drive portion 49 is attached to the piston main body portion 48 .
[0037] The cylinder 18 is a hollow cylindrical member which extends in the axial direction so as to accommodate the piston 16 . The cylinder 18 is supported so as to be fixed to the compressor container 14 . The cylinder 18 includes a cylinder fixing end portion 58 which is fixed to the compressor container 14 , and a cylinder main body portion 60 which extends from the cylinder fixing end portion 58 toward the piston 16 in the axial direction. The discharge chamber 40 is formed in the cylinder fixing end portion 58 . The cylinder main body portion 60 includes a cylinder inner surface 62 which slidably supports the piston 16 in the axial direction. A cylinder partition portion 64 is provided between the cylinder fixing end portion 58 and the cylinder main body portion 60 . A cylinder communication hole 66 is formed at the center of the cylinder partition portion 64 . The cylinder communication hole 66 communicates with the discharge chamber 40 and the pressurization chamber 38 . The discharge valve 44 is accommodated in the discharge chamber 40 , and is configured so as to open and close the cylinder communication hole 66 by a pressure difference between the discharge chamber 40 and the pressurization chamber 38 .
[0038] The linear actuator 20 is configured to be driven so as to reciprocate the piston 16 in the axial direction. A forward movement and a backward movement of the piston 16 in the axial direction are periodically repeated by the driving of the linear actuator 20 . The forward movement of the piston 16 is a upward movement in FIG. 2 , and the backward movement of the piston 16 is a downward movement in FIG. 2 . For example, the linear actuator 20 is a linear vibration actuator which vibrates the piston 16 in the axial direction.
[0039] The leaf spring unit 22 is a bearing which allows reciprocation of the piston 16 in the axial direction and restricts the movements of the piston 16 in the radial direction and the circumferential direction. The leaf spring unit 22 includes a plurality of leaf springs 23 . The plurality of leaf springs 23 are arranged in series in the axial direction, and for example, include at least ten leaf springs 23 . In the plurality of leaf springs 23 , each leaf spring 23 elastically supports the piston 16 to the compressor container 14 such that the piston 16 can reciprocate in the axial direction. Each leaf spring 23 extends along a plane perpendicular to the axial direction. The leaf spring 23 is referred to as a flexure spring, is soft in the reciprocation direction of the piston 16 , and is rigid in the direction perpendicular to the reciprocation direction.
[0040] The plurality of leaf springs 23 are disposed so as to be adjacent to each other with gaps in the axial direction. The leaf springs 23 are disposed with gaps in the axial direction such that the leaf springs 23 do not come into contact with each other. For example, the gas between two leaf springs 23 adjacent to each other in the axial direction is determined such that the two leaf springs 23 do not come into contact with each other by elastic deformation generated by the reciprocation of the piston 16 . In order to maintain an appropriate gap, a spacer or a pressing member may be provided between two leaf springs 23 .
[0041] In this way, an axial vibration system is configured in which the piston. 16 is provided as a mass element and the leaf spring unit 22 is provided as an elastic element. For example, the vibration system is designed so as to provide a desired resonant frequency by appropriately setting axial stiffness of each leaf spring 23 of the leaf spring unit 22 . The vibration system is driven by the linear actuator 20 .
[0042] An axial movable region on design of the piston 16 is determined so as to apply a cycle of a desired volume change to the high-pressure chamber 26 (for example, pressurization chamber 38 ). For example, the axial movable region of the piston 16 may be determined such that the piston 16 (for example, piston tip portion 46 ) abuts on or comes into contact with a facing portion (for example, cylinder partition portion 64 ) of the cylinder 18 at a top dead center when the piston 16 moves forward, and the tip surface of the piston 16 is separated from the facing portion of the cylinder 18 by a predetermined distance at a bottom dead center when the piston 16 moves backward. Alternatively, the axial movable region may be determined to a predetermined separation distance such that the tip surface of the piston 16 does not come into contact with the facing portion of the cylinder 18 at the top dead center.
[0043] Here, a basic operation of the linear compressor 10 will be described. As described above, the low-pressure working gas 34 is recovered from the outside of the linear compressor 10 to the low-pressure chamber 28 through the suction pipe 32 . When the piston 16 moves to the bottom dead center or the vicinity thereof, the intake valve 42 is opened and the discharge valve 44 is closed. The low-pressure working gas 34 is supplied from the second piston recessed portion 52 to the pressurization chamber 38 through the piston communication hole 56 . When the piston 16 moves forward from the bottom dead center to the top dead center, the intake valve 42 is closed, and the working gas inside the pressurization chamber 38 and the discharge chamber 40 is compressed so as to be boosted.
[0044] When the piston 16 moves to the top dead center or the vicinity thereof, the discharge valve 44 is opened, and the high-pressure working gas 36 is supplied from the discharge chamber 40 to the outside of the linear compressor 10 through the discharge pipe 30 . When the piston 16 moves backward from the top dead center to the bottom dead center, the discharge valve 44 is closed, and the working gas inside the pressurization chamber 38 and the discharge chamber 40 is expanded so as to be decompressed. When the piston 16 is returned to the bottom dead center or the vicinity thereof, the intake valve 42 is opened, and the low-pressure working gas 34 is supplied to the pressurization chamber 38 again. In this way, a compression cycle is repeated in the linear compressor 10 .
[0045] FIG. 3 is a sectional view schematically showing a valve structure 70 of a valved nonlubricated linear compressor according to an embodiment of the present invention. The valve structure 70 includes a valve seat portion 74 having a valve hole 72 , an elastic valve body member 76 , an elastic pressing member 78 , and a fixing member 80 . The valve structure 70 is disposed between a first gas chamber 82 and a second gas chamber 84 . The first gas chamber 82 communicates with the second gas chamber 84 through the valve hole 72 . When the valve structure 70 is closed, the valve structure 70 blocks the first gas chamber 82 from the second gas chamber 84 . The valve structure 70 blocks a flow of a working gas between the first gas chamber 82 and the second gas chamber 84 through the valve hole 72 . Meanwhile, the valve structure 70 is open, the valve structure 70 allows the first gas chamber 82 to communicate with the second gas chamber 84 . The valve structure 70 allows the flow of a working gas between the first gas chamber 82 and the second gas chamber 84 through the valve hole 72 .
[0046] The valve structure 70 may be the above-described intake valve 42 . In this case, the valve hole 72 and the valve seat portion 74 respectively correspond to the piston communication hole 56 and the piston partition portion 54 shown in FIG. 2 . The first gas chamber 82 and the second gas chamber 84 respectively correspond to the high-pressure chamber 26 and the low-pressure chamber 28 . Alternatively, the valve structure 70 may be the above-described discharge valve 44 . In this case, the valve hole 72 and the valve seat portion 74 respectively correspond to the cylinder communication on hole 66 and the cylinder partition portion 64 shown in FIG. 2 . The first gas chamber 82 and the second gas chamber 84 respectively correspond to the discharge chamber 40 and the pressurization chamber 38 .
[0047] The valve seat portion 74 includes a valve hole portion 74 a having a valve hole 72 , and a valve body support wall portion 74 b which extends laterally from the valve hole portion 74 a . The valve hole portion 74 a is a portion of the valve seat portion 74 which defines the valve hole 72 , and the valve body support wall portion 74 b which is a portion of other portions of the valve seat portion 74 which does not have the valve hole 72 . Accordingly, the valve hole portion 74 a and the valve body support wall portion 74 b may be respectively referred to as a wall portion with a hole and a wall portion without a hole of the valve seat portion 74 .
[0048] The valve seat portion 74 extends to be flat along a surface perpendicular to the axial direction (similarly to FIG. 2 , vertical direction in FIG. 3 ). The valve body support wall portion 74 b is continuous to the valve hole portion 74 a such that the flat surface of the valve body support wall portion 74 b is formed along with the valve hole portion 74 a . For example, in a case where the valve seat portion 74 have a circular plate shape, the valve hole portion 74 a may occupy a semicircular region (alternatively, a fan-shaped region or an arc-shaped region) which is positioned on one side of the circular plate, and the valve body support wall portion 74 b may occupy a semicircular region (alternatively, a fan-shaped region or an arc-shaped region) positioned on a side opposite to the valve hole portion 74 a.
[0049] The elastic valve body member 76 includes a first elastic plate-shaped portion 76 a and a second elastic plate-shaped portion. 76 b . The first elastic plate-shaped portion 76 a is disposed along the valve hole portion 74 a so as to cover the valve hole 72 . The second elastic plate-shaped portion 76 b extends laterally from the first elastic plate-shaped portion 76 a and is disposed along the valve body support wall portion 74 b . The first elastic plate-shaped portion 76 a can be elastically deformed with respect to the second elastic plate-shaped portion 76 b so as to open the valve hole 72 by a pressure difference between the first gas chamber 82 and the second gas chamber 84 . The elastic valve body member 76 may be a leaf spring which is soft in the axial direction and is rigid movement of the first elastic plate-shaped portion 76 a with respect to the valve hole 72 is shown by broken lines in FIG. 3 . The elastic valve body member 76 operates as a valve body which can be elastically displaced so as to open and close the valve hole 72 .
[0050] The first elastic plate-shaped portion 76 a and the second elastic plate-shaped portion 76 b form an integral member (that is, elastic valve body member 76 ) which is continuous to each other. For example, in a case where the elastic valve body member 76 has a circular plate shape, the first elastic plate-shaped portion 76 a may be a semicircular portion. (alternatively, a fan-shaped region or an arc-shaped region) which is positioned on one side of the circular plate, and the second elastic plate-shaped portion 76 b may be a semicircular portion (alternatively, a fan-shaped region or an arc-shaped region) positioned on a side opposite to the first elastic plate-shaped portion 76 a . In addition, the elastic valve body member 76 includes a slit 76 c which is positioned between the first elastic plate-shaped portion 76 a and the second elastic plate-shaped portion 76 b.
[0051] The elastic pressing member 78 is disposed along the second elastic plate-shaped portion 76 b so as to be elastically deformed along with the elastic valve body member 76 . The elastic pressing member 78 has a planar shape which is defined so as to expose the first elastic plate-shaped portion 76 a . In this way, the elastic pressing member 78 is positioned at a location corresponding to the valve body support wall portion 74 b (that is, a wall portion without a hole) of the valve seat portion 74 . The elastic pressing member 78 is not present on the valve hole portion 74 a , and thus, an upward space of the first elastic plate-shaped portion 76 a in the axial direction is open.
[0052] The elastic pressing member 78 may have the same thickness as that of the elastic valve, body member 76 . Alternatively, the elastic pressing member 78 may have a thickness different from that of the elastic valve body member 76 . By adjusting the thickness of the elastic pressing member 78 , it is possible to adjust axial stiffness of the elastic pressing member 78 .
[0053] One surface of the elastic valve body member 76 is in contact with the valve seat portion 74 , and the other surface of the elastic valve body member 76 is in contact with the elastic pressing member 78 . More specifically, one surface of the first elastic plate-shaped portion 76 a is in contact with the valve hole portion 74 a , and the other surface thereof is not in contact with any member. One surface of the second elastic plate-shaped portion 76 b is in contact with the valve body support wall portion 74 b , and the other surface thereof is in contact with the elastic pressing member 78 .
[0054] Moreover, if necessary, any plate-shaped or film-shaped member may be interposed between the elastic valve body member 76 and the valve seat portion 74 . In addition, any plate-shaped or film-shaped member may be interposed between the elastic valve body member 76 and the elastic pressing member
[0055] The fixing member 80 fixes the elastic valve body member 76 and the elastic pressing member 78 to the valve seat portion. 74 in a state where the elastic valve body member 76 is interposed between the elastic pressing member 78 and the valve seat portion 74 . For example, the fixing member 80 may be a fastening member such as a bolt. Each of the valve seat portion 74 , the elastic valve body member 76 , and the elastic pressing member 78 may have a through-hole (for example, bolt hole) through which the fixing member 80 passes.
[0056] FIG. 4 is a plan view schematically showing the elastic valve body member 76 shown in FIG. 3 . The elastic valve body member 76 includes a fulcrum portion 76 d and a connecting portion 76 e in addition to the first elastic plate-shaped portion. 76 a and the second elastic plate-shaped portion 76 b . The fulcrum portion 76 d is separated from the first elastic plate-shaped portion 76 a by the slit 76 c . The slit 76 c is an arc-shaped slit., and partially surrounds the fulcrum portion 76 d . The connecting portion 76 e radially extends from the fulcrum portion 76 d to the side opposite to the slit 76 c . The connecting portion 76 e connects the fulcrum portion 76 d to the second elastic plate-shaped portion 76 b . The second elastic plate-shaped portion 76 b is continuous to the first elastic plate-shaped portion 76 a in the circumferential direction. Since a center angle of the arc-shaped slit is greater than 180°, a center angle of the connecting portion 76 e is smaller than 180°. According to this, the first elastic plate-shaped portion 76 a has a fan shape having a center angle which is greater than 180°, and the second elastic plate-shaped portion 76 b has a fan shape having a center angle which is smaller than 180°.
[0057] The fulcrum portion 76 d is positioned at the center of the elastic valve body member 76 . The fulcrum portion 76 d has a through-hole 76 f , through which the fixing member 80 passes, at the center of the fulcrum portion 76 d . Accordingly, the fulcrum portion 76 d has an annular shape which surrounds the through-hole 76 f . The fulcrum portion 76 d is fixed to the valve body support wall portion 74 b by the above-described fixing member 80 .
[0058] FIG. 5 is a plan view schematically showing the elastic pressing member 78 shown in FIG. 3 . The elastic pressing member 78 has the same shape as that of a portion of the elastic valve body member 76 in a plan view. The elastic pressing member 78 includes the elastic plate-shaped portion 78 b , the fulcrum portion 78 d , and the connecting portion 78 e , which respectively have shapes similar to those of the second elastic plate-shaped portion 76 b , the fulcrum portion 76 d , and the connecting portion 78 e of the elastic valve body member 76 in a plan view. In addition, the elastic pressing member 78 includes notches 78 c corresponding to both ends of the slit 76 c of the elastic valve body member 76 , and a through-hole 78 f corresponding to the through-hole 76 f of the elastic valve body member 76 . The fulcrum portion 78 d of the elastic pressing member 78 is fixed to the valve body support wall portion 74 b along with the fulcrum portion 76 d of the elastic valve body member 76 by the above-described fixing member 80 .
[0059] FIG. 6 is a top view schematically showing the valve structure 70 shown in FIG. 3 . Accordingly, the elastic valve body member 76 , the elastic pressing member 78 and the fixing member 80 are shown in FIG. 6 . In addition, for easy understanding, the valve holes 72 are by broken lines in FIG. 6 . In this example, the valve structure 70 includes three valve holes 72 .
[0060] As shown in FIGS. 3 and 6 , the first elastic plate-shaped portion 76 a is disposed so as to cover the valve holes 72 , and the second elastic plate-shaped portion 76 b is disposed in the region in which the valve holes 72 are not present. The elastic pressing member 78 is superposed on the elastic valve body member 76 , and similarly to the second elastic plate-shaped portion 76 b , is disposed in the region in which the valve holes 72 are not present. The fixing member 80 fixes the elastic valve body member 76 and the elastic pressing member 78 .
[0061] An operation of the valve structure 70 having the above-described configuration will be described. The valve structure 70 is opened and closed by the pressure difference between the first gas chamber 82 and the second gas chamber 84 . When the pressure of the first gas chamber 82 increases with respect to the pressure of the second gas chamber 84 and the pressure difference between two chambers exceeds a predetermined threshold value, the first elastic plate-shaped portion 76 a is elastically displaced with respect to the second elastic plate-shaped portion 76 b (arrow D in FIG. 3 ). The first elastic plate-shaped portion 76 a is separated from the valve hole portion 74 a . As a result, a working gas flows (arrow G in FIG. 3 ) from the second gas chamber 84 into the first gas chamber 82 through the valve holes 72 . Accordingly, the valve structure 70 is opened.
[0062] Thereafter, when the pressure difference between the two chambers is lower than the predetermined threshold value, the first elastic plate-shaped portion 76 a is returned (arrow E in FIG. 3 ) to the initial position by a restoring force. The first elastic plate-shaped portion 76 a comes into contact with the valve hole portion 74 a again. The flow of the working gas from the second gas chamber 84 to the first gas chamber 82 is blocked. Accordingly, the valve structure 70 is closed.
[0063] FIG. 7 is a sectional view schematically showing a portion of a reed valve having a stopper 86 . The stopper 86 is disposed such that the tip portion thereof is separated from the valve hole 88 in the axial direction. A reed valve body 90 is separated from the stopper 86 so as to cover the valve hole 88 . As shown by broken lines, when the reed valve body 90 opens the valve hole 88 , an axial movement of the reed valve body 90 is restricted by the stopper 86 . Since a lift amount of the reed valve body 90 is limited, a flow rate of the gas flowing through the valve is relatively small. In addition, collision of the reed valve body 90 with respect to the stopper 86 may generate noise.
[0064] However, according to the embodiment described with reference to FIGS. 1 to 6 , the above of the first elastic plate-shaped portion 76 a in the axial direction is open, and the valve structure 70 does not have the stopper which limits the movement of the elastic valve body member 76 . Accordingly, it is possible to relatively increase the lift amount of the elastic valve body member 76 . The flow rate of the gas flowing through the valve structure 70 increases, and the flow rate of the gas discharged by the linear compressor 10 increases. In addition, since the stopper is not present, collision noise generated by opening and closing of the valve structure 70 decreases.
[0065] When the first elastic plate-shaped portion 76 a is axially displaced, the second elastic plate-shaped portion 76 b is elastically deformed. The elastic pressing member 78 is elastically deformed according the elastic deformation of the second elastic plate-shaped portion 76 b In this way, the elastic pressing member 78 is integrally deformed with elastic valve body member 76 , compared with a case where the elastic pressing member 78 is not present, it is possible to alleviate stress when the elastic valve body member 76 is elastically deformed. For example, stress concentration in the connection portion 76 e and the second elastic plate-shaped portion 76 b is alleviated. Accordingly, it is possible to prolong a service life of the elastic valve body member 76 .
[0066] In addition, the planar shape of the elastic valve body member 76 contributes an increase in the lift amount. The first elastic plate-shaped portion 76 a is separated from the fulcrum portion 76 d by the slit 76 c and the first elastic plate-shaped portion 76 a is connected to the fulcrum portion 76 d by the second elastic plate-shaped portion 76 b and the connecting portion 76 e . In addition, the fulcrum portion 76 d is positioned at the center of the elastic valve body member 76 . In this way, it is possible to lengthen the spring length of the elastic valve body member 76 . Accordingly, the valve structure 70 having a large lift amount is obtained.
[0067] FIG. 8 is a sectional view schematically showing the valve structure 70 of a valved nonlubricated linear compressor according to another embodiment of the present invention. As shown in FIG. 8 , the elastic valve body member 76 includes a fluoropolymer layer 92 . A contact surface between the elastic valve body member 76 and the valve seat portion 74 is covered with the fluoropolymer layer 92 . Moreover, both surfaces of the elastic valve body member 76 may be covered with the fluoropolymer layers 92 . For example, the fluoropolymer layer 92 is formed of polytetrafluoroethylene (PTFE). Accordingly, it is possible to decrease collision noise between the elastic valve body member 76 and the valve seat portion 74 . In addition, seal performance during closing of the valve structure 70 , that is, sealability of the valve hole 72 b the elastic valve body member 76 is improved.
[0068] FIG. 9 is a sectional view schematically showing the valve structure 70 of a valved nonlubricated linear compressor according to still another embodiment of the present invention. The valve structure 70 includes a fluoropolymer member 94 which is disposed between the valve seat portion 74 and the elastic valve body member 76 . The fluoropolymer member 94 may be a film, a sheet, or a plate which is formed of a fluoropolymer such as polytetrafluoroethylene (PTFE). The fluoropolymer member 94 is disposed along the valve seat portion 74 . One surface of the fluoropolymer member 94 is in contact with the valve seat portion 74 , and the other surface of the fluoropolymer member 94 is in contact with the elastic valve body member 76 .
[0069] The fluoropolymer member 94 has a planar shape similar to the elastic valve body member 76 except for having the opening portion 96 . The opening portion 96 is formed at the location corresponding to the valve hole 72 . Accordingly, the working gas passes through the valve hole 72 and the opening portion 96 . The opening portion 96 may be a hole, a slit, or other opening portions.
[0070] The fluoropolymer member 94 may have the same thickness as that of the elastic valve body member 76 . Alternatively, the fluoropolymer member 94 may have a thickness different from that of the elastic valve body member 76 . In this way, the thickness of the fluoroplymer member 94 can be greater than that of the fluoropolymer layer 92 shown in FIG. 8 . This contributes a decrease in collision noise between the elastic valve body member 76 and the valve seat portion 74 .
[0071] The opening portion 96 may be a hole having the same shape as that of the valve hole 72 . The opening portion 96 may be a hole having a shape different from that of the valve hole 72 . For example, the opening portion 96 may be a hole which is smaller than the valve hole 72 . In a case where the fluoropolymer member 94 has flexibility in the axial direction, and it is possible to axially lift the fluoropolymer member 94 by interaction between the working gas passing through the valve hole 72 and the fluoropolymer member 94 . This contributes a decrease in noise during opening and closing of the valve structure 70 .
[0072] It should be understood that the invention is not limited to the above-described embodiment, but may be modified into various forms on the basis of the spirit of the invention. Additionally, the modifications are included in the scope of the invention.
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A valve structure includes: a valve seat part furnished with a valve hole portion having a valve hole connecting a first gas chamber to a second gas chamber, and a valve-body supporting wall part laterally extending from the valve hole portion; an elastic valve-body member furnished with a first elastic platelike section disposed paralleling the valve hole portion, and a second elastic platelike section extending from the first elastic platelike section, wherein the first elastic platelike section is elastically deformable against the second elastic platelike section under pressure differential between the first gas chamber and the second gas chamber such as to open the valve hole; and an elastic pressing member arranged paralleling the second elastic platelike section such as to elastically deform together with the elastic valve-body member, and being of planar form determined such as to expose the first elastic platelike section.
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RELATED APPLICATION
This application is a continuation-in-part application of U.S. patent application Ser. No. 12/500,805, filed Jul. 10, 2009, which in turn is a continuation-in-part of U.S. patent application Ser. No. 11/747,481, filed May 11, 2007, which in turn is a continuation-in-part of U.S. patent application Ser. No. 11/041,322, filed Jan. 24, 2005, now U.S. Pat. No. 7,390,841, U.S. patent application Ser. No. 12/049,668, filed Mar. 17, 2008 and U.S. patent application Ser. No. 12/098,613 filed Apr. 7, 2008, and the entire description and claims of these applications are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to heavy metal-free and anaerobically compostable polymeric compositions and articles having indoor and outdoor utilities with effective anaerobic landfill degradation. Articles of the polymer compositions are also made into composites having an hydrophobic polymer surface layer and an underlying hydrolyzable biodegradable polymer layer which biodegrade in landfills in a relatively short time.
BACKGROUND OF THE INVENTION
For many years it has been desired to make plastic materials from polymers such as polyvinyl chloride (PVC), polyvinyl acetate (PVAc), and olefin polymers (EPDM) which are either biodegradable by microorganisms or environmentally degradable such as in a landfill. In spite of considerable efforts, landfills are becoming inundated with plastic materials, and articles made therefrom, that will not degrade perhaps for centuries. This is especially true for vinyl halide and olefin polymer materials such as PVC and EPDM that are considered non-biodegradable, that is, they persist in landfills under anaerobic conditions indefinitely without noticeable decomposition. This factor limits the acceptance of PVC and polyolefins in many products where their useful balance of properties and low cost would be attractive. An example is that of printable film and sheet. If a sample of EPDM or flexible (plasticized) PVC is tested per ASTM D 5526, Standard Test Method for Determining Anaerobic Biodegradation of Plastic Materials Under Accelerated Landfill Conditions, there is no appreciable weight loss or change in appearance after 100 days at 97° F. in contact with simulated household waste. In contrast, cellulosic polymers and other biodegradable plastics, such as polylactic acid and polycaprolactone, are completely consumed.
There has been a particular need for a compostable polymer composition for use in many end products such as polyvinyl chloride, polyvinyl acetate or olefin polymer films, banners, billboards, signs, laminates, ink jet media, diapers, hygienic pads and the like. These products must satisfy properties for practical purposes such as tear strength, tensile and impact strengths to function in many useful articles. However, the same properties that make them useful lead to their lack of biodegradability. PVC, PVAc and olefin polymers have achieved widespread usage. However, the explosive growth of such thermoplastics or elastomers has aggravated the problem of disposing of them, and has caused their accumulation in landfills. Very little of these polymeric waste products degrade in most landfills because of anaerobic conditions. The problem has become aggravated because of the shortage of landfills and municipalities are seeking to restrict the use of plastics because of their inability to degrade in landfills.
Environmental concerns with existing polymer stabilizers have stimulated interest in alternative stabilizers including organic based stabilizers. For example, in the pipe industry, PVC has long been stabilized with heavy metals, such as lead and cadmium. However, in Europe, replacement of lead-based stabilizers is currently one of the main focuses. As part of the voluntary initiative of Vinyl 2010, the European Vinyl Industry is committed to replace lead stabilizers in all PVC applications by 2015. Thus, there has been considerable interest in developing a new generation of environmentally acceptable heavy metal-free PVC stabilizers that prevent degradation and change in color during processing, and also provide tangible benefits to the manufacturer of useful articles.
In addition to providing useful PVC plastic articles which are free of heavy metal stabilizers, it would be highly desirable to also make them compostable. Thus, plastic articles that are capable of withstanding environmental conditions could be made and their degradation by sunlight, moisture, temperature, and the like prevented during their service life. Plastic products for practical purposes must satisfy such properties as water impermeability and sufficient mechanical properties, such as tear, tensile and impact strengths to function in useful articles. For example, there is a particular need for indoor or outdoor signs, billboards, banners, images, protective barriers, backdrops, and building wall coverings to provide plastic sheet material which will withstand outdoor environmental conditions. In the case of disposable health care products, diapers, underpants, hygienic pads, and the like, these products must also satisfy such properties as water impermeability in order to prevent seepage of urine or other human waste products therethrough. Further, for health care and waste management, there are needs for disposable plastic products such as medical tubing, bags and utensils that are biodegradable.
SUMMARY OF THE INVENTION
This invention is directed to heavy metal-free and anaerobically compostable vinyl halide polymeric compositions and articles, such as a composite polymeric sheet. The compostable articles are typically hydrophobic due to the vinyl halide polymers employed in their manufacture. In view of the hydrophobic nature of the polymers employed, the articles are well-suited for environmental use by withstanding conditions such as sunlight, moisture, humidity, and the like. They are therefore very adaptable for fabricating useful articles that can withstand environmental or use conditions. However, the polymeric compositions and articles are anaerobically compostable because they contain an organotitanate or an organozirconate as an anaerobic prodegradant, in relative amounts to render the polymer compostable in a landfill. In addition, the compositions contain a heavy metal-free organic based heat stabilizer that enables their fabrication into useful articles without degradation of vinyl halide polymer. Where polymer composites are made, the surface layer can he hydrophobic and the underlying layer can be a hydrolyzable biodegradable polymer which enables the entire article to be compostable in the landfill. Therefore, this invention satisfies environmental concerns involved in the fabrication, use, and disposal of vinyl halide polymer compositions.
More particularly, a suitable polymeric composition or article contains a vinyl halide polymer which may be a thermoplastic or elastomeric polymer. The term “vinyl halide” as used herein and understood in the art is intended to cover organic polymers consisting of long chains of carbon atoms and includes the addition of halogen atoms into the polymer chain of carbon atoms, such as polyvinyl chloride (PVC). Polymers are selected from the group consisting of a vinyl halide polymer, or copolymers or blends thereof. Composite articles of these polymers containing heavy metal-free stabilizers and anaerobic prodegradants with normally biodegradable polymer structures can be made according to this invention. In the case of the biodegradable thermoplastic polymer, suitable polymers include polylactic acid (PLA), polyvinyl alcohol polycaprolactone (PCL), polyamide, polyacrylamide, polyacrylate, polymethacrylate, polyester, and cellulose, and copolymers or blends thereof.
This invention is also directed to a method of anaerobic biodegradation of polymeric articles in a landfill. The method is practiced by introducing an article or a physically reduced form thereof into a landfill for anaerobic degradation. The article is comprised of an hydrophobic vinyl halide polymer containing an organic based heat stabilizer and an organotitanate or an organozirconate as a prodegradant in relative amounts to render the article anaerobically compostable. The organic based heat stabilizer is also contained in an amount to heat stabilize the vinyl halide polymer or copolymer during fabrication into a useful article. In the case of composite articles, for example, a polymeric surface layer contains the stabilizer and prodegradant, and underlying the hydrophobic surface layer can contain an hydrolyzable biodegradable thermoplastic polymer layer. Each layer is thus compostable or biodegradable in the landfill. Moreover, the heavy metal-free useful articles or composite articles having the hydrophobic vinyl halide polymer composition or surface layer enable environmental servicing utilities and, when introduced into a landfill, are anaerobically compostable.
DETAILED DESCRIPTION OF THE INVENTION
As reported in the above-identified Ser. No. 11/041,322 patent application, polyvinyl chloride compositions have been formulated with plasticizer and stabilizer along with the prodegradant composition. Polymeric sheets containing this composition and composites with woven or nonwoven sheets have been made compostable. Such compositions consist of (a) PVC; (b) a plasticizer selected from the group of completely aliphatic carboxylic acid esters; (c) a heat stabilizer selected from the group of sulfur-free dialkyl and monoalkyltin carboxylates; and (d) an anaerobically prodegradant reactive organotitanate or organozirconate. As reported in the above-identified Ser. No. 11/747,481 patent application, further unobvious and unexpected improvements have been made. In particular, compositions of vinyl halide resins such as PVC, even without plasticizer, are compostable when the prodegradant system is employed. In addition, it has also been found that the reactive organotitanate or organozirconate can be broadened to include other monomeric adducts in addition to the amide adduct disclosed in the above-identified Ser. No. 11/041,322 patent application. For instance, an ester adduct of the organotitanate or organozirconate and an organotin compound, in relative amounts, has been found to render the vinyl halide polymer composition compostable, even in the absence of a plasticizer. The above-identified applications Ser. Nos. 12/098,613, 12/049,668, and 12/500,805 are directed to further improvements in compositions, articles, and composites for other polymer systems, such as an olefin polymer and a vinyl acetate polymer.
This application is directed to further improvements in anaerobically compostable vinyl halide polymeric compositions and articles which anaerobically degrade in landfills. The compositions and articles are formulated with organic based heat stabilizers (“OBS stabilizers”) which are free or essentially free of heavy metals such as lead, cadmium, or tin. Compostable polymer compositions or articles having very useful hydrophobic surfaces or layers comprise, for example, a vinyl halide (PVC) polymer and a monomeric adduct of an organotitanate, or organozirconate, as a prodegradant in relative amounts to render the polymer composition compostable. As employed herein, the term “adduct” is intended to mean a complex association of the monomeric molecule and the organotitanate or organozirconate molecule. It was previously reported that amide salts of the neoalkoxy modified monoalkoxy titanate or zirconate achieved the objectives of the invention. The amide salts were defined particularly by methacrylamide as the monomeric adduct of the reactive titanate or zirconate. It has also been found that the ester adducts of the specific organotitanates or zirconates can also function in the prodegradant of this invention. The monomeric ester of the organotitanate or organozirconate adduct is exemplified by dimethylaminoethyl methacrylate. It has also been found that the dimethylaminopropyl acrylamide is as effective as the methacrylamide.
The compositions and composites of this invention, as well as useful articles made therefrom, are compostable. “Compostable” means that the composition or sheet undergoes chemical, physical, thermal and/or biological degradation such that it may be incorporated into and is physically indistinguishable from finished compost (humus) and which ultimately mineralizes (biodegrades) to C0 2 , water and biomass in the environment like other known compostable matter such as paper and yard waste. The compostable films and composites are anaerobically biodegradable. “Biodegradable” means that the composition or composite is susceptible to being assimilated by anaerobic microorganisms when buried in the ground, e.g., a landfill under conditions conducive to their growth. For purposes of this invention, “compostable” is intended to mean anaerobically biodegradable by microorganisms.
Anaerobic composting conditions that enable the chemical, physical, thermal and/or biological degradation of the composition or composite may vary. The compositions, articles or composites of this invention are especially adapted to be compostable in municipal solid waste composting facilities or landfills. For example, following ASTM D 5526-94 (reapproved 2002), Standard Test Method for Determining Anaerobic Biodegradation of Plastic Materials Under Accelerated Landfill Conditions, samples of PCV, PVAC and EPDM were degraded, incorporated into and physically indistinguishable in the test landfill.
Compostable polymer compositions, articles, and composites of this invention, their method of manufacture and compostability will be understood with reference to the following detailed description. The hydrophobic vinyl halide polymer in the article or article surface layer is broadly defined herein as a polymer which includes thermoplastic or elastomeric polymers. More preferably, it includes a vinyl halide polymer, copolymers and blends thereof as follows.
Vinyl Halide Polymer
The vinyl halide resin employed is most commonly a homopolymer of vinyl chloride, i.e., polyvinyl chloride. It is to be understood, however, that this invention is not limited to a particular vinyl halide resin such as polyvinyl chloride (PVC) or its copolymers. Other halogen-containing polymers or resins which are employed and which illustrate the principles of this invention include chlorinated polyethylene, chlorosulfonated polyethylene, chlorinated polyvinyl chloride, and other vinyl halide polymer or resin types. Vinyl halide polymer or resin, as understood herein, and as appreciated in the art, is a common term and is adopted to define those resins or polymers usually derived by polymerization or copolymerization of vinyl monomers including vinyl chloride with or without other comonomers such as ethylene, propylene, butene, hexene, octene, a diene, vinyl acetate, vinyl ethers, vinylidene chloride, methacrylate, acrylonitrile, acrylates, styrene, etc. A simple case is the conversion of vinyl chloride H 2 C═CHC1 to polyvinyl chloride (CH 2 CHCI—)n wherein the halogen is bonded to the carbon atoms of the carbon chain of the polymer. Other examples of such vinyl halide resins would include vinylidene chloride polymers, vinyl chloride-vinyl ester copolymers, vinyl chloride-vinyl ether copolymers, vinyl chloride-vinylidene copolymers, vinyl chloride-propylene copolymers, chlorinate polyethylene, and the like. Of course, the vinyl halide commonly used in the industry is the chloride, although others such as bromide and fluoride may be used. Examples of the latter polymers include polyvinyl bromide, polyvinyl fluoride, and copolymers thereof.
Composites with Biodegradable Polymers
As stated above, composites of vinyl halide polymers and normally biodegradable polymers can be made according to of this invention. Such normally biodegradable polymers include polylactic acid (PLA), polyvinyl alcohol (PVA), polycaprolactone (PCL), polyamide, polyacrylamide, polyacrylate, polymethacrylate, polyester, and cellulose, and copolymers or blends thereof. Other examples of biodegradable polymers suitable for use are those which enable the manufacture of useful articles or composites such as sheet materials. These articles are formed in a number of ways such as by extrusion molding, coextrusion of a surface layer and underlying layer into a composite sheet, for example. The sheets may also be made by lamination of the layers, combined coextrusion-lamination techniques or coating techniques.
Anaerobic Prodegradant Organotitanate or Organozirconate
As disclosed in the above identified application Ser. No. 11/041,322, and more recently, the Ser. No. 12/500,805 application, the anaerobic prodegradant of this invention is an organozirconate or organotitanate. The monomeric adducts of the organozirconate or titanate are exemplified by the monomeric groups of dimethylaminopropyl acrylamide, methacrylamide, dimethylaminoethyl methacrylate, and other similar reactive monomeric groups as detailed herein. In a broader sense, the adducts more preferably comprise dialkylamino-short alkylchain-reactive monomers. The prodegradant may be defined more particularly as follows.
The chemical description and chemical structure of organotitanates or zirconates have been well developed. Kenrich Petrochemicals, Inc. is a manufacturer of these products and, hereinafter, the Kenrich products are interchangeably identified with the prefix “Kenrich”, “K”, “KR”, and “LICA”. For instance, Kenrich LICA 38J is a reactive titanate under the chemical name titanium IV neoalkanolato tri(dioctyl)pyrophosphate-O (adduct) N-substituted methacrylamide. Furthermore, with zirconium substituted for titanium, Kenrich produces NZ 38 under the chemical description zirconium IV neoalkanolato tri(dioctyl)pyrophosphate-O (adduct) N-substituted methacrylamide. These compounds are generally referred to as amide salts of neoalkoxy modified monoalkoxy titanate or zirconate. While the invention has been exemplified hereinafter with these amide adducts of these specific organotitanates or organozirconates and other prodegradants, it is to be understood that other similar compounds can achieve the objectives of this invention.
The K38J pyrophosphato titanium adduct is the reaction product of K38+ dimethylaminopropyl methacrylamide (DMPDMA), according to the following structure where R′=methyl, R″=propyl, R=butyl, n˜3.
K38=the above structure without DMPDMA. K38 is titanium IV neoalkanolato tri(dioctyl)pyrophosphate-O. These two ingredients react rapidly at room temperature when mixed in stoichiometric proportions (close to 3:1). P—OH becomes P—O − and R2N, R3N+. A bright red color develops, which is the thermochromic, indicating coordination of likely C═O to titanium, which displays such colors when penta-coordinate instead of tetra-coordinate. (For example, acetone.TiCl4 is orange-red, and the precursors, colorless.) Neither K38 nor DMPDMA cause depolymerization of olefin polymers when used alone. However, if added separately to the olefin polymer, the combination in situ is as effective as K38J. Thus, use of the term “adduct” is intended to cover the use of preformed complex or the separate addition of the components to enable their association or complexing in situ to provide the prodegradant effects of this invention.
A substituted methacrylamide can also be employed as an adduct of the organotitanate or zirconate. For instance, Kenrich Ken-React KR-238J is another reactive titanate where the monomeric adduct is a substituted methacrylamide. The KR-238J is a dimethylaminopropyl methacrylamide which has been found to be as effective as the methacrylamide adduct of Kenrich-38J, described above. A chemical description of KR-238J is titanium IV ethylenedialato bis(dioctyl)pyrophosphato ethylene titanate (adduct) N-substituted methacrylamide. Furthermore, dimethylaminoethyl methacrylate, a monomeric ester adduct, is equally effective in combination with the pyrophosphato form of the titanium or zirconium coupling agent. The K238J adduct has the chemical structure as follows:
K238=the above structure without DMPDMA. Thus, as used herein “K38 and “K238” are intended to mean the organopyrophosphato titanate portion of the adduct which is complexed with the monomeric amide, ester, or other like monomers, and the resulting adduct is referred to herein as K38J and K238J, respectively. Specific compounds are exemplified by titanium IV neoalkanolato tri(dioctyl)pyrophosphato-O (adduct) N-substituted methacrylamide and zirconium IV neoalkanolato tri(dioctyl)pyrophosphato-O (adduct) N-substituted methacrylamide, titanium IV neoalkanolato bis(dioctyl)pyrophosphato-O (adduct) N,N-dimethylamino-alkyl propenoamide, and zirconium IV neoalkanolato bis(dioctyl)pyrophosphato-O (adduct) N,N-dimethylamino-alkyl propenoamide.
The above monomeric adducts result from salt or complex formation via the titanate/zirconate acidic —P═O(OH) group. The monomer contains a basic functional group that will react to form a salt (but not go on to other reactions such as oxidation). A tertiary amine group is favorable. This could be a dialkyl amine group, methyl pyridine functionality or a range of basic nitrogen heterocyclic groups. The rest of the reactive momomer must contain an activated carbon-carbon double bond. The C═C bond, to be activated, should be conjugated with C═O, as in an ester, ketone, aldehyde or amide, with —CN, with oxygen as in a vinyl ether, or with oxygen, nitrogen or sulfur in an allylic linkage, or with an aromatic ring as in styrene or vinyl ferrocene.
In a more generalized form as set forth the above identified applications Ser. Nos. 11/747,481 and 12/500,805, the adducts can be defined as:
Organotitanate or Zirconate —P═O(OH)-Salt Forming Group-R—C═C-Activating Group,
where R is a hydrocarbon radical or substituted hydrocarbon radical and the activating group is conjugated with the C═C.
It has been found that a nitrate or sulfonate group, e.g. “X” may be substituted for the phosphate group and the results of this invention may be achieved. Thus the adducts may be defined as:
Organotitanate or Zirconate —X-Salt Forming Group-R—C═C-Activating Group
where X is a phosphate, nitrate or sulfonate group, R is a hydrocarbon radical or substituted hydrocarbon radical and activating group has a C═O, —CN, oxygen, nitrogen, sulfur, or an aromatic ring conjugated with the C═C to activate the carbon-carbon double bond, wherein the substituent of the substituted hydrocarbon radical is selected from the group consisting of an ether, thioether, ester, thioester, and amide.
Other monomers of the adducts of this invention are exemplified by the following:
These organotitanates or zirconates are further described in considerable detail in the following U.S. Patents which are incorporated herein in their entireties by reference, namely, U.S. Pat. Nos. 4,069,192; 4,080,353; 4,087,402; 4,094,853; 4,096,110; 4,098,758; 4,122,062; 4,152,311; 4,192,792; 4,202,810; 4,261,913; 4,277,415; 4,338,220; 4,417,009; 4,512,928; 4,600,789; 4,623,738.
Also, products equivalent to Kenrich K38J and K238J are made by Nanjing Capatue Chemical Co., Ltd. of the Peoples' Republic of China, under the marks Ti Link TCA-L38J and TCA-K238A. Other information on these quat titanates and zirconates may be obtained with reference to Capatue Chemical publication of products entitled Organometallic Coupling Agents at www.Capatue.com and this information is incorporated herein by reference.
The above-identified patents have been granted to Monte et al., and assigned to Kenrich Petrochemicals, Inc. The patents are directed to coupling agents and conform to the following general formula:
(RO—) n -M-(OXR 1 Y) 4-n
The M group in the above general formula is representative of titanium or zirconium. The coupling agents disclosed in the above-identified patents are generally referred to in the art as organotitanates or organozirconates. For example, the functions of the groups in the above general formula for the above titanates or zirconates have been described in the above patents and a paper entitled, “Neoalkoxy Titanate and Zirconate Coupling Agent Additives in Thermoplastics”, Monte, S. J., Kenrich Petrochemicals, Inc., Polymers and Polymeric Composites (2002), 10 (II), 121-172. In addition, reference may be made to Handbook of Polymer Additives and Modifiers, Chapter 75: by Grossman, R. F., Coupling Agents; pp. 993-1000 (Van Nostrand 1992). The literature, as represented by these publications, has disclosed the merits of using organotitanates or organozirconates in polymer compositions to essentially increase the stability of the polymeric compositions, especially those compositions containing fillers or reinforcing agents, to provide an overall better balance of processing and properties in the manufacture of useful polymeric articles. However, in accordance with the principles of this invention, it has been found that useful hydrocarbon polymer compositions may be rendered anaerobically biodegradable in landfills by employing certain monomeric forms of organotitanates or zirconates as anaerobic prodegradants.
Accordingly, the following modified general formula is proposed to explain the anaerobic prodegradants functions as used according to the principles of this invention:
(RO)- n -M(XY) 4-n
With an RO-M bond, M is a metal capable of forming a bond to an aliphatic carbon atom that has sufficient stability to permit addition to a polymeric composition and subsequent processing. In addition, the RO-M bond must not add toxicity and M is titanium or zirconium. The metal must also be able to expand its octet, that is, to form addition complexes with greater than tetrahedral coordination, and is involved in mediating carbon-carbon bond scission. The RO— group is designed to provide mobility in a polymer matrix.
In this invention, it has been found that groups, such as “X”, can be placed on M that attract microbes, the latter being taken to designate bacteria, archaea, cyanobacteria, unicellular or cell cluster algae and fungi. These microbes require a hydrophilic site, such as provided by certain of the organotitanates and zirconates disclosed in the Kenrich references. The “Y” group provides the monomeric adduct which complexes or forms a salt with the X group of the organotitanate or zirconate as expressed in the more generalized formula above. The X groups found effective in attracting microbes include phosphate, nitrate and sulfonate. These ligands have provided other benefits, per the above Kenrich patents, but have never previously been shown to promote anaerobic landfill degradation. It is hypothesized that these oxygenated anions enable oxidation of hydrocarbon polymers by microbes anaerobically in landfills according to this invention. If the microbe-attracting group is designated ˜, then the general formula is (RO) n -M(X ˜ Y) 4-n .
The microbe-attracting groups X ˜ may be ligands on M or functional groups on RO. The microbe-attracting ligand (˜) itself, in some cases, may have specific affinity for the polymer. Whatever the mechanism or theory, monomeric adducts of organotitanates or zirconates have not been employed as anaerobic prodegradants in useful hydrophobic hydrocarbon polymer composition, articles and landfill degradation.
Organic Based Heat Stabilizer
As indicated in the Background of the Invention, environmental concerns with heavy metal stabilizers have stimulated interest in alternative stabilizers. It has been found, according to principles of this invention, that organic based heat stabilizers (herein sometimes simply “OBS”) may be substituted for heavy metal based stabilizers or other metal based stabilizers, and the synergistic effects of heat stabilization to make useful articles and to provide for anaerobically compostable vinyl halide compositions may still be achieved.
A preferred OBS stabilizer that has been found environmentally acceptable while still enabling the fabrication benefits and anaerobic compostability in accordance with the principles of this invention, is a pyrimidinedione, having the following structure:
XR 3 : electron—donating group
R 1-3 : alkyl, phenyl, hydrogen
However, in accordance with the principles of this invention, other heavy metal-free organic based stabilizers are considered to be within the scope of this invention. Such OBS stabilizers include pyrimidinedione, dicyandiamide, urea, quanadine, tetrahydropyranyl esters or ethers, organic thiols, melamine, and hydrazides, for instance. These OBS stabilizers that have been referred to in the patent art such as U.S. Pat. Nos. 3,928,285; 4,948,827; 6,667,357; 6,762,231; 6,747,081; and 6,927,247. U.S. Pat. No. 3,660,331 describes tetrahydropyranylethers or esters that may be employed in heat stabilizing vinyl halide polymers. Belgian Patent No. 616,642, Netherlands 6,410,105, West German 1,140,705, British 986,161 and U.S. Pat. Nos. 3,084,135; 3,194,786, and 2,367,483 are disclosures of organic based thermal stabilizers for vinyl halide polymers. Thus, the term “organic based thermal or heat stabilizer” and the components or compositions embraced thereby, which are essentially free of heavy metals, are known to those of skill in the art. However, this invention is predicated in part upon the employment of such a stabilizer in combination with the prodegradant which enables the anaerobic compostability of useful articles that have been fabricated employing vinyl halide resins and an OBS stabilizer.
Prodegradant Synergistic Composition
As earlier reported in application Ser. No. 11/747,481, it has been discovered that the prodegradant behavior of organotitanate or organozirconate adduct, i.e., the organopyrophosphato monomeric adduct, displays an unpredicted synergism in the compostability of vinyl halide polymers which are employed in an article or the composite article surface layer. Further improvements have been made as reported hereinafter for the prodegradants and polymers. The remarkable anaerobic compostability properties exist over ranges of ratios of the essential components. The exact mechanism for the unexpected results and the compostability of polymers with the prodegradants is not completely understood. Certainly there are theories which could be proposed, but regardless of theories, the beneficial results evident in the numerous examples of this invention which follow, in further view of this detailed description, speak for themselves. Applicant relies upon these empirical demonstrations of the principles of this invention to advance its merit.
With the prodegradant or OBS stabilizer of this invention, it has been found that the total composition of prodegradant or OBS stabilizer is useful over a range of about 1 to about 10 parts (phr) by weight based upon 100 parts by weight of the vinyl halide polymer. The most useful range is on the order of about 1 to about 5 phr.
The principles of this invention and its operating parameters will be further understood with reference to the following detailed examples which serve to illustrate the types of specific OBS stabilizers and prodegradants and their amounts as used in typical polymer formulations and the compostabilities displayed by the prodegradant of this invention. These examples are considered to be exemplary of this invention and should not be considered as limiting, especially in view of applicant's broad disclosure of the principles of this invention.
The compostability of the polymer compositions of the following Examples was determined by following ASTM D 5526-94 (reapproved 2002), Standard Test Method for Determining Anaerobic Biodegradation of Plastic Materials Under Accelerated Landfill Conditions. Using the standard test, a mixture was prepared comprising 60% by weight of sterilized dehydrated manure (to simulate processed household waste), at different percentages of distilled water (35% or 60%), and 10% fermenting inoculum from an active composter. Film samples of the compostable vinyl halide, vinyl acetate, and other polymers were run in the Examples which follow. All experiments were run at 97° F. in a dark incubator.
EXAMPLE 1
A plastisol was mixed comprising 100 parts PPG (Geon 121) in a dispersion resin, 80 parts of di-isononyl adipate (Exxon), 5 epoxidized soybean oil, 2 parts of an organic based heat stabilizer of pyrimidinedione having a structure which is exemplified above (Mark OBS 1200 developed by Crompton Vinyl Additives GmbH, Chemtura Company) and five parts of LICA 38J, identified above. The plastisol is coated as a 2 mil film on release paper using a wire wound bar. After ten days in an ASTM D 5526 landfill at 90-95° F., the film sample had been largely consumed, most having been replaced by bacterial colonies. In sixty days, the sample had vanished.
EXAMPLE 2
Example 1 was repeated, except that one part of LICA 38J was employed instead of five parts. After ten days in an ASTM D 5526 landfill at 90-95° F., the sample showed colonies forming at the surface and some edge erosion.
The above Examples 1 and 2 illustrate the use of the heavy metal-free organic based heat stabilizer in combination with the prodegradant to achieve the advantages of this invention. To illustrate the results with other heavy metal-free organic based heat stabilizers, other organic stabilizers may be employed. For example, the following comparative Examples are used to illustrate that a number of organic stabilizers may be substituted for the organotin stabilizers of Comparative Examples 3-46. Examples have been identified in the specification above, such as pyrimidinedione, dicyandiamide, urea, quanadine, tetrahydropyranyl esters or ethers, organic thiols, melamine, and hydrazides.
COMPARATIVE VINYL HALIDE POLYMER EXAMPLES 3-25
In each of the examples 3-14, as follows, standard resin formula was employed which contained 100 parts by weight polyvinyl chloride homopolymer (Geon 121 PVC by B.F. Goodrich). Included in the standard formula was a plasticizer such as di-octyl adipate (DOA) or di-isodecyl phthalate (DIDP). Examples 15-19 illustrate other polymer/copolymer blends and unplasticized compositions. Examples 20-25 illustrate the sulfonate and nitrate analogues of the phosphate ligand of the prodegradant.
The compostability of the PVC compositions of the examples was determined by following ASTM D 5526-94 (reapproved 2002), Standard Test Method for Determining Anaerobic Biodegradation of Plastic Materials Under Accelerated Landfill Conditions. Using the standard test, a mixture was prepared comprising 60% by weight of sterilized dehydrated manure (to simulate processed household waste), 30% distilled water, and 10% fermenting inoculum from an active composter. 50 g were used in sealed Petri dishes with 2 by 1 inch samples of PVC composition or composite sheet material. All experiments were run at 97° F. in a dark incubator.
EXAMPLE 3
A plastisol was mixed with consisting of 100 parts PVC (Geon 121), 80 parts di-isodecyl phthalate (DIDP), and 2 parts dibutyltin dilaurate (DBTDL) heat stabilizer; coated as a 2 mil film on release paper and fused. Samples were unchanged after 90 days exposure to the test conditions of ASTM D 5526-94. The procedure was repeated using di-octyl adipate (DOA) in place of DIDP. After 90 days, there was visible mold growth on the film but no visible evidence of decomposition. The procedure was repeated with the addition of 2.5 parts of a 4% solution of isothiazolone biocide (MICRO-CHEK 11, Ferro Corporation). In this case, there was no evidence of mold growth after 90 days.
EXAMPLE 4
The plastisol of Example 3 was mixed using DOA, DBTDL plus 5 parts of titanium neoalkanato, tri(dioctyl)pyrophosphato-O-(adduct)-N-substituted methacrylamide (Kenrich LICA 38J). Fused samples were consumed in the test landfill within 10 days, vanishing to the visible eye. The experiment was repeated adding 2.5 parts of MICRO-CHEK 11 biocide, with identical results.
EXAMPLE 5
The plastisol of Example 3 was mixed with DBTDL, LICA 38J and, replacing DOA with the di-isononyl ester of cyclohexane dicarboxylic acid (DINCH, BASF). Upon testing per ASTM D 5526-94 method, fused samples disappeared in 7 days, with or without added biocide.
EXAMPLE 6
Example 5 was repeated with the zirconate analog of LICA 38J (Kenrich N Z 38J). Upon testing per ASTM D 5526-94 method, fused samples disappeared within 10 days.
EXAMPLE 7
The plastisol was mixed using DINCH, LICA 38J and dibutyltin maleate ester heat stabilizer (PLASTISTAB 2808, Halstab) in place of DBTDL. Upon testing per ASTM D 5526-94 method, fused samples disappeared within 10 days.
EXAMPLE 8
The plastisol was mixed using DINCH, LICA 38J, and 2 parts of a liquid calcium/zinc stabilizer (PLASTISTAB 3002, Halstab) in place of DBTDL organotin. After 90 days, the fused sample had heavy mold growth and had fragmented but was still visibly of the same dimensions.
EXAMPLE 9
Control samples were run for comparison. Upon testing per ASTM D 5526-94 method, samples of untreated filter paper showed mold growth within week and were consumed in 30 days. A sample of polylactic acid (PLA) 2 mil film was completely consumed in seven days. A sample of 1 mil low density polyethylene (LDPE) film was unchanged after 90 days.
EXAMPLE 10
A plastisol was mixed consisting of 100 parts Geon 121 PVC, 80 parts DOA, 2 parts DBTDL stabilizer and 5 parts of LICA 38, which is the titanate LICA 38J without the methacrylamide adduct. After 30 days at 971F per ASTM D 5526, there was no visible sign of decomposition. The same result was found with NZ 38, the zirconate bases for NZ 38J, and with 5 parts of methacrylamide itself. These tests establish that the methacrylamide adduct of the organotitanate or zirconate is necessary for compostability.
EXAMPLE 11
A plastisol was mixed consisting of 100 parts PVC, 80 parts DOA, 5 parts LICA 38J organotitanate-methacrylamide adduct, and 2 parts of dibutyltin di-isothioglycolate (SP1002, Ferro Corporation). After 30 days, there was only minor decomposition. This probably reflects the antioxidant capability of organotin mercaptides. It also presently establishes the preferred organotin carboxylates in the prodegradant system.
EXAMPLE 12
Example 11 was repeated using the following stabilization system: epoxidized soybean oil (ESO)—2 parts; phenyl di-iso-decyl phosphite—2 parts; zinc stearate—0.2 parts. After 30 days, there was no visible compostability, probably due to the antioxidant capability of the phosphite that would be used in most mixed metal stabilizer systems. In this case there was, however, notable mold growth, so it is possible that there might be eventual decomposition (period of years). Repetition using ESO containing 4% isothiazolone biocide led to no mold growth.
EXAMPLE 13
As described previously, plastisol was mixed consisting of 100 parts Geon 121 PVC, 80 parts DOA, 2 parts DBTDL, and 5 parts of Kenrich LICA 38J reactive titanate. To this was added 5 parts of VULCABOND MDX (Akzo Nobel) bonding agent. The plastisol was coated on polyester fabric and fused to a coating of about 5 mils thickness.
A sample of this coated fabric with the inventive prodegradant system and a control sample of a commercial finished product of the same construction (without the prodegradant system) were exposed at 90° F. per ASTM D5526 conditions,. After two weeks exposure, the control sample was essentially unchanged. The inventive sample has lost almost all trace of plastisol to the landfill, the only remnants being that which penetrated intersections of the fabric mesh. The fabric shows evidence of some decomposition and it is anticipated that the polyester will slowly decompose.
EXAMPLE 14
In Examples 3-13, the PVC samples were plasticized with DOA or DIDP in combination with a prodegradant system which was the adduct of K-38 and dimethylaminopropyl methacrylamide (DMPDMA). In order to demonstrate the effectiveness of the monomeric adduct in comparison to each of the adduct components, Examples similar to 3-13 were repeated with each of the adduct components alone. None of the components of the adduct, alone, caused depolymerization of the halogenated polymers. However, if each of the components of the adduct were added separately to the PVC compound, and reacted in situ, the combination was as effective as adding the adduct. Accordingly, it has been presently demonstrated that the monomeric adduct of the organotitanate or zirconate is essential in order to obtain the desired results of the prodegradant system.
EXAMPLE 15
1.5 grams of Poval (Kuraray) LM-20, a partially hydrolyzed polyvinyl acetate, having a number average molecular weight (Mn) of about 20,000 were dissolved in 50 grams of ethanol. The solution was coated on release liner to form a two-mil film when dry. Two grams of the dried film were placed in 50 grams of landfill composition per ASTM D 5526 containing 35% water; two grams were also placed in 50 grams of landfill composition having 60% water content. After ninety days at 35% moisture, the film was intact with a weight gain of about 6%. After ninety days at 60% moisture, the film appeared softened, and had gained about 10% in weight. There was no evidence of microbial growth. The cast film was clear and accepted pencil and ballpoint. It adhered strongly to 3M #142 pressure-sensitive tape
EXAMPLE 16
Example 13 was repeated with UCAR VYHH (Dow) PVC/VAC, which is a copolymer of polyvinyl chloride and vinyl acetate at 14% vinyl acetate, with a number average molecular weight (Mn) of about 10,000. Two films were cast from methylisobutylketone with two parts per hundred of dibutyltin dilaurate (DBTDL) heat stabilizer added. This Example demonstrates that when the vinyl copolymer of vinyl acetate with vinyl chloride is employed, stabilizer is added. The samples were translucent, accepted pencil and ballpoint ink, and had strong adhesion to 3M #142 tape. The samples showed no measurable weight loss after 90 days' exposure, either at a 35% or 60% moisture level, nor evidence of surface mold growth.
EXAMPLE 17
Example 16 was run with the addition of 2 phr of LICA 38J at 35% water, weight loss after 30 and 60 days was 65% and 96%, respectively. At 60% water, weight loss after 30, 60, and 90 days was 12%, 20%, and 27%, respectively. This Example demonstrated, at various moisture levels, landfill compostability of the composition. This Example 17 may be compared to Example 13 in the earlier application Ser. No. 11/747,481, filed May 11, 2007, for the purpose of demonstrating unplasticized PVC/VAC polymer compositions. The VYHH PVC copolymer with 14% vinyl acetate was employed in that Example 13. As reported in that Example 13, the VYHH PVC/VAC copolymer with vinyl acetate does not itself decompose into the landfill, nor does this occur with 2-5 phr of K-38, which is the titanate component of the adduct. However, samples containing the prodegradant system of 5,1, and 0.5 phr K38J adduct and 2 phr DBTL organotin depolymerization or compostability was observed upon performing the ASTMD 5526 conditions. Accordingly, when using the prodegradant system of K38J and organotin, after 60 days at 35° C. in the dark, no visual traces of the PVC/VAC copolymer were observed. These Examples 17 (in this application) and Example 13 of the patent application Ser. No. 11/747,481, demonstrate that unplasticized halogenated copolymers with vinyl acetate will effectively decompose with the prodegradant of this invention.
EXAMPLE 18
Example 17 was run using the 1:1 of UCAR VYHH PVC/VAC and Poval LM-20 PVAc, identified as above. At both moisture levels of 65% and 96%, the polymer had vanished into the landfill in 30 days. The 2 ml cast film was transparent, readily accepted pencil and ballpoint marking, and adhered strongly to 3M #142 tape. The sample exposed to UV-A radiation at 40° C. for 30 days (Q-panel) showed no discoloration. The sample, when ignited with a match, self-extinguished.
EXAMPLE 19
Example 18 was run using a blend of UCAR VYHH PVC/VAC and ELVAX-40, previously identified, at both 35 and 60 percent moisture levels, weight loss after 30 days was 45-50%, and 100% after sixty days. Accordingly, these Examples further illustrate the compostability of vinyl acetate copolymers according to the principles of this invention.
EXAMPLES 20-25
The purpose for these following Examples 20-35 is to demonstrate the effectiveness of sulfonate and nitrate analogs of the phosphate ligand in the above-identified prodegradant compounds. The hydrophobic hydrocarbon base polymer consisted of 100 parts PVC (Geon 121), 45 parts di-iso-nonyl adipate (DINA), 20 parts calcium carbonate, 6 parts titanium dioxide, 2.5 parts epoxidized soybean oil (ESO), and 2 parts of dimethyltin maleate. To the base PVC polymer composition was added 2 phr of LICA (KR) 38J and 2 phr of KR 238J, identified above, which served as Examples 20 and 21. Example 22 employed Kenrich 262J, which is the same compound as LICA 238J, but sidechains on the phosphorus are methyl and butyl instead of octyl. In other words, KR 262J is titanium IV bis(butyl, methyl)-pyrophosphato-O ethylenediolato (adduct) with DMAPMA. As used herein “DMAPMA” means N-substituted methacrylamide, above identified. Kenrich 262ESJ is the monomeric adduct of titanium IV bis(butyl, methyl)pyrophosphato-O ethylenediolato (adducts) bis(dioctyl)hydrogen phosphite and DMAPMA. For comparison with Examples 20-23, sulfate and nitrate analogs of the phosphate ligand of the prodegradants LICA 38J, 238J, and 262J were employed. In the case of Example 24, the sulfonate analog employed was titanium IV bis-2-propenolato-butanolato-tris-dodecylbenzenesulfonate (adduct) DMAPMA. In the case of Example 25, the nitrate analog was Kenrich 134J, which is the titanium IV bisphenylpropyl-phenolato-oxoethylenediolato (adducts) sorbitol nitrate and DMAPMA. The nitrate adduct was 1:1 DMAPMA adduct of the reaction product of 1:1 molar sorbitol nitrate and KR 134J. KR134J=titanium IV bis[4-(2 phenyl) 2-propyl-2]phenolato oxyethylenediolato.
All of the above PVC polymer compositions containing the prodegradant adducts having the phosphate, sulfate, and nitrate ligands were coated on release paper using a wire-bound bar infused at 150° C. to yield 2-3 mil coatings. 2 grams of each were placed on 50 grams of landfills medium per ASTM D5526. (21.5 grams sterilized sewage=milorganite, 7.5 grams of active compost, 21 grams of water, pH after 24 hours=7.8, CO 2 and NH 3 levels OK per the Solvita compost maturity spot test procedure). These were in crystal styrene petri dishes maintained at 35° C. in a dark incubator after being sealed. After 90 days, all of the above had vanished into the landfill except for a scatter of filter and pigment particles.
All of the above operating and comparative Examples describe the invention so that a person of skill in the art will be enabled to practice it.
Those of ordinary skill in the art realize that the descriptions, procedures, methods and compositions presented above can be revised or modified without deviating from the scope of the described embodiments, and such do not depart from the scope of the invention.
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Heavy metal-free compostable polymers, composites and articles anaerobically biodegrade in landfills in a relatively short time. Heavy metal-free composite polymeric articles and sheets such as indoor or outdoor signs, billboards, banners, images, protective barriers, backdrops and wall coverings have very useful service durations and yet are landfill biodegradable.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a Divisional of pending U.S. patent application Ser. No. 09/032,256, filed Feb. 27, 1998.
TECHNICAL FIELD
This invention relates to clocked integrated circuits that deliver data, and more particularly to a method and apparatus for adjusting the timing of data presented to an output terminal relative to a clock signal.
BACKGROUND OF THE INVENTION
Clock signals are used by a wide variety of digital circuits to control the timing of various events occurring during the operation of the digital circuits. For example, clock signals are used to designate when command signals, data signals, and other signals used in memory devices and other computer components are valid and can thus be used to control the operation of the memory device or computer system. For instance, a clock signal can be used to develop sequential column addresses when an SDRAM is operating in burst mode.
Retrieving valid data from a clocked memory device at a specified time can be difficult to coordinate. After a memory address is selected, the data travels out of the selected memory cell, is amplified, passes through configuration circuitry (if the memory chip has multiple configurations) and passes through an output buffer before the data is read. Before the advent of synchronous memory circuits, data simply appeared at an output terminal following a propagation delay after the data was requested. In a synchronous memory circuit, data delivery is synchronized with a clock signal. Many circuits have been created to coordinate data signals with clock signals, with varying degrees of success. Two of the problems to solve are determining how fast and with what regularity the data signal propagates through the chip circuitry. Because data output is often coordinated with a clock signal that is external to the memory chip, computer simulations of signal propagation within a chip are performed to align the external clock signal with the data delay of the synchronous memory device. Static time delays are then designed into the memory circuit based on the simulation predictions. Because of production variations, improper assumptions, and other factors ultimately causing timing errors, the data does not always arrive at the output terminal at the desired time. As computer clock speeds increase, the window for providing valid data to the output terminal closes, making it more difficult to ensure the correct delivery time of data from the memory circuit.
An example of a circuit that provides data to a data pad at a specific time relative to an external clock is shown in FIG. 1 . An output circuit 2 includes a memory array 5 that contains an array of individual memory cells (not shown). Once a particular memory cell is selected to be read, complementary signals corresponding to the contents of the memory cell travel to a pair of respective I/O and I/O* lines. The signals on the I/O and I/O* lines are sensed and amplified by a data sensing circuit 10 , which produces a DATA* signal at an output. An external clock signal is received at a clock circuit input 7 and passes through clock circuitry 15 to become a CLKDOR* signal. The CLKDOR* signal may differ from the external clock signal in a variety of ways, including phase, orientation, and duty cycle, however, their overall periodic cycle length is the same. Oftentimes, to properly match timing of the data arriving at the data pad with the external clock signal, a static delay is added within the clock circuitry 15 .
The DATA* signal is presented to a passgate 20 and passed to an output node 21 when the signal CLKDOR* signal is HIGH and its complement from an inverter 17 is LOW. From the output node 21 , the DATA* signal is input to a NOR gate 30 along with a TRISTATE signal. An output from the NOR gate 30 leads to a passgate 24 . When the CLKDOR* signal is LOW and its complement from the inverter 17 is HIGH, the output from the NOR gate 30 passes through the passgate 24 and becomes the signal DQHI. Another NOR gate 32 combines the output of the NOR gate 30 with the TRISTATE signal. This output from the NOR gate 32 is presented to a pair of passgates 22 , 26 . The passgate 22 receives the signal from the NOR gate 32 and, when the CLKDOR* signal is LOW and its complement from the inverter 17 is HIGH, feeds it back to the output node 21 . The passgate 26 passes the signal it receives from the NOR gate 32 as an output signal DQLO when the signal CLKDOR* is LOW and its complement from the inverter 17 is HIGH.
If the signal DQHI is HIGH, a pull-up circuit 36 raises a DQ pad 40 to a HIGH voltage. Conversely, if DQLO is HIGH, it activates a pull-down circuit 38 to pull the DQ pad 40 to a ground voltage. The output circuit 2 is designed so that the pull-up circuit 36 and the pull-down circuit 38 cannot operate simultaneously. When neither the pull-up circuit 36 nor the pull-down circuit 38 is active, the DQ pad 40 is neither pulled up to a HIGH voltage nor pulled down to ground, but instead remains in a high-impedance state.
The circuit operation of the data delivery circuit 2 will now be explained. When the CLKDOR* signal is HIGH and the DATA* signal is HIGH, a HIGH signal passes to the output node 21 . Assuming that the TRISTATE signal is low to enable the NOR gates 30 and 32 so they act as inverters, when the CLKDOR* signal goes LOW, the passgate 22 couples the output of the NOR gate 32 to the input of the NOR gate 30 , output node 21 . The NOR gates 30 and 32 then latch the HIGH at the output node 21 to the output of the NOR gate 32 . At the same time, a LOW is latched to the output of the NOR gate 30 . The HIGH at the output of the NOR gate 32 is coupled through the passgate 26 to the pull-down circuit 38 . The HIGH signal DQLO causes the pull-down circuit 38 to pull the DQ pad 40 to ground. At the same time, the LOW signal at the output of the NOR gate 30 passes through the passgate 24 . The LOW DQHI signal does not activate the pull-up circuit 36 , as explained above. Alternatively, if the DATA* signal is LOW, a LOW signal is passed to the output node 21 when the CLKDOR* signal is HIGH. When the CLKDOR* signal drops LOW, the LOW signal at the output node 21 is latched by the NOR gates 30 and 32 , is fed back to the output node 21 through the passgate 22 , and also propagates through the passgate 26 to make DQLO LOW. Concurrently, the LOW signal at the data output node 21 causes the NOR gate 30 to output a HIGH signal that passes through the passgate 24 to provide a HIGH DQHI signal. The HIGH DQHI signal causes the pull-up circuit 36 to connect the DQ pad 40 to a HIGH voltage. If the TRISTATE signal is HIGH, neither DQHI nor DQLO will be HIGH regardless of the state of the DATA* signal. Thus, the DQ pad 40 floats in a high impedance state.
When a computer system is designed, specifications for signal timing are determined. Some of the signals and timings used in the design are shown in FIG. 2 . One of the design specifications is an access time, T AC , used to designate a maximum time between a rising edge of an external clock signal and when a valid data signal arrives at the DQ pad 40 . Additionally, another specified time parameter is the output hold time, T OH , indicative of a minimum time for how long the data will be held at the DQ pad 40 following a subsequent rising edge of the external clock. For example, as illustrated in FIG. 2, a READ command signal is input to a memory circuit sometime between a rising edge of a clock pulse CP 0 and a clock pulse CP 1 . At a time CP 1 , the READ command is latched and read by the memory circuit, indicating data is to be read from a memory cell in a memory array. The data is read from the array and placed at the DQ pad 40 under the control of the CLKDOR* signal. The specification T AC indicates a maximum time until the desired data is placed on the DQ pad 40 . The data is held at the DQ pad 40 for a time no less than the specification T OH , as measured from a subsequent clock pulse after the READ command is latched. As shown in FIG. 2, T AC1 is the time measured from CP 2 until Data 1 is stable on the DQ line. T AC2 is the time measured from CP 3 until Data 2 is stable on the DQ line, and so on. The time T AC1 will be nearly identical to the other access times T AC2 , T AC3 , etc. under the same operating conditions. Also shown in FIG. 2, T OH1 is the time measured from the next clock pulse following when Data 1 appears on the DQ line, i.e., CP 3 , to the time when Data 1 begins to transition off the DQ line. As above, the measured hold times T OH2 , T OH3 , etc. will be nearly identical to one another under similar operating conditions.
During the design phase of a memory chip, a designer determines how much after each clock pulse the CLKDOR* signal should fire. This delay determines when the data is made available on the DQ line relative to the external clock signal. Typically, a delay value is chosen that provides a tolerance for both the T AC and T OH parameters. If the CLKDOR* signal fires too soon after the external clock signal, the chip will easily pass the T AC specification, but may fail the T OH specification. If the CLKDOR* signal fires too late, the chip will easily pass the T OH specification but may fail the T AC specification. These time compensations, by virtue of being fabricated as part of the circuit, generally cannot be changed after manufacture of an integrated circuit. When memory chips fail their timing specifications, they are sold as lesser quality chips for a reduced price, or even destroyed. Thus, there is an economic incentive to maximize the number of chips that meet or exceed the timing specifications. As a consequence of increasing computer speeds, this already small window for proper data timing is reducing. Because of process variations, errors in design assumptions, the wide range of temperatures and voltages in which the chips are warrantied to perform, and other factors, an increasing number of memory chips fail to meet the increasingly stringent design specifications.
SUMMARY OF THE INVENTION
An adjustable data delay circuit comprises a clocked data passing circuit that receives a clock signal and a data signal. An adjustable time delay circuit is coupled to the clock signal for adjusting the time the data is delivered to an output terminal relative to the clock signal. The adjustable time delay circuit includes a plurality of delay gates, each individually selected by control signals. One path in the time delay circuit that includes the desired delay gate is selected by the control signals. The clock signal passing through the selected delay gate is then used to control the time when the data is delivered to the output terminal.
In one embodiment, the control signals are made by selectively coupling a pattern of control inputs to a reference voltage.
In another embodiment, the passgates are arranged in a plurality of columns such that each column has a number of passgates that is an integer power of 2.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a conventional clocked data delivery circuit.
FIG. 2 is a timing diagram of various signals during the operation of the clocked data circuit of FIG. 1 .
FIG. 3 is a schematic diagram of an adjustable clocked data circuit according to one embodiment of the present invention.
FIG. 4A is a schematic diagram of a delay adjusting circuit according to one embodiment of the present invention.
FIG. 4B is a chart showing how different delay times are selected using one embodiment of the present invention.
FIG. 5A is a schematic diagram of a conventional adjustable impedance device.
FIG. 5B is a schematic diagram of another conventional adjustable impedance device.
FIG. 6 is a block diagram of a synchronous dynamic random access memory including the adjustable time delivery circuit of FIG. 3 .
FIG. 7 is a block diagram of a computer system including the random access memory of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of an adjustable time delay circuit 102 in accordance with the invention is illustrated in the schematic diagram of FIG. 3 . The adjustable delay circuit 102 includes some of the same components as the output circuit 2 , shown in FIG. 1 . Identical components of the output circuit 2 and the adjustable time circuits 102 have been given the same reference numbers, and for the sake of brevity, identical components will not be described in further detail. The adjustable time data circuit 102 includes a delay adjusting circuit 60 located between the clock circuitry 15 and the control inputs to the passgates 20 , 22 , 24 , and 26 . As later described, the delay adjustment circuit 60 can be located in various places in the adjustable delay circuit 102 , and is shown in this location of the adjustable delay circuit 102 for illustration.
As shown in FIG. 4A, the CLKDOR* signal is input to the delay adjusting circuit 60 at an input terminal 62 . From there it is split into four paths, passing through a delay circuit 70 , having a delay of 1.0; a delay circuit 72 , having a delay of 0; a delay circuit 74 , having a delay of 0.5; and a delay circuit 76 , having a delay of 1.5. The delay times 0, 0.5, 1.0, and 1.5 are an indication of relative measure and do not necessarily indicate a specific time period. These delay times are selected such that the delay that would have been designed into the output circuit 2 appears as a middle value of the range of delay values eligible for selection. In this way, the data delivery of a memory chip can be “accelerated” by selecting a delay time shorter than the built-in delay of the prior art circuit, or “decelerated” by selecting a delay time longer than the built-in delay of the prior art circuit. The output signals from the delay circuits 70 , 72 , 74 , and 76 are input to a passgate 80 , a passgate 82 , a passgate 84 , and a passgate 86 , respectively. The passgates 80 , 82 , 84 , and 86 are controlled by a control signal A and its complement formed by passing A through an inverter 92 . The signals from the passgates 80 and 82 combine as an input to a passgate 88 , and the signals from the passgates 84 and 86 combine as an input to a passage 90 . The outputs from the passgates 88 and 90 connect at an output terminal 95 , and form an output signal OUT. The passgates 88 , and 90 are controlled by a control signal B and its complement formed by passing B through an inverter 94 .
Referring back to FIG. 2, the benefits of having an adjustable CLKDOR* signal will be described. As previously stated, adding delay to the CLKDOR* signal in relation to the CLK signal allows the designer to provide a tolerance for the T AC and T OH specifications. After the chip is produced, the T AC and T OH specifications, and others, are tested. If the chip does not pass all of the specifications, it cannot be sold at the current market price for the highest quality chips. By including an adjustable timing circuit within the memory chip, chips that do not meet the T AC and T OH specifications after manufacture may be able to be adjusted in order to meet the specifications.
For example, the specifications may direct that T AC can be no more than 6 ns and T OH cannot be less than 3 ns. Assume that T AC1 measured 4 ns and T OH1 measured 2.5 ns. The specification for T AC is easily passed (the shorter the better), but the chip fails the T OH specification because it does not hold the data for a long enough time on the DQ lines. By adding a 1 ns delay to the time when the CLKDOR* signal fires, the chip can be brought within the specifications. The T AC1 increases to 5 ns (still passing the 6 ns specification) and the T OH1 increases to hold the data valid on the DQ lines for 3.5 ns, passing the 3 ns specification.
The delay adjusting circuit 60 of FIG. 4A is controlled by control signals A and B. These control signals provide a HIGH or LOW signal to the passgates depending on a state of a respective adjustable impedance circuit 96 . Two different kinds of adjustable impedance devices are shown, one in FIG. 5 A and one in FIG. 5 B. One type of adjustable impedance circuit 96 is a circuit containing an antifuse 65 , shown in FIG. 5 A. The antifuse 65 is made from a pair of conducting plates 110 and 112 separated by a dielectric material 115 . Antifuses are devices similar to small capacitors. They have a natural and a blown state. When the antifuse 65 is in a natural state, the dielectric material 115 electrically insulates the pair of plates 110 and 112 . Because the dielectric material 115 is intact, the node C is electrically insulated from the ground voltage. To change the antifuse 65 to its blown state, a high electric field is passed across the dielectric material 115 by raising C gnd to a programming voltage, for example, 10 volts, while enabling a PROGRAM transistor. This is usually done after chip fabrication and packaging, but can be completed before packaging. When the high electric field is placed across the dielectric material 115 , it breaks down and loses its insulative properties. This allows the plates 110 and 112 to contact one another creating a relatively low resistive contact. When blown, the antifuse 65 couples the node C to the node C gnd , that is normally held at the ground voltage, unless the antifuse is being programmed, as described above. To test the state of the antifuse 65 a Read* signal is strobed LOW. That connects node C to the Vcc voltage. If the antifuse 65 is blown, the node C is quickly brought down to ground. An inverter 50 causes a HIGH signal to be sent to a BLOWN output. The HIGH signal also keeps a HOLD transistor OFF. Conversely, if the antifuse 65 is in its natural state, node C will not be pulled down to ground and BLOWN will carry a LOW signal. This low signal also enables the HOLD transistor, keeping node C at the voltage Vcc.
The other adjustable impedance circuit 96 , shown in FIG. 5B contains a fuse 68 . The fuse 68 also has a natural and a blown state. In its natural state, the fuse 68 couples a node D to the ground voltage. The fuse 68 is blown by passing a high current through it, or by some other means such as cutting it with a laser, for example. When the fuse 68 is blown, the node D is disconnected from the ground voltage. As with the antifuse 65 , the fuse 68 may be blown before or after packaging. Also as described above, the adjustable impedance circuit 96 of FIG. 5B is read in a similar manner. The Read* signal strobes LOW raising a node D to the Vcc voltage. If the fuse 68 is intact, node D is coupled to ground and BLOWN is LOW. This LOW signal passes through an inverter 52 to keep the HOLD transistor OFF. If the fuse is blown, node D is charged to Vcc and BLOWN is pulled HIGH.
Referring back to FIG. 4A, the adjustable impedance circuits 96 may be either of the structures shown in FIGS. 5A or 5 B. By coupling the signals A and B to a voltage using antifuses 65 or fuses 68 , the manufacturer can easily select the signals A and B to be either HIGH or LOW, as desired. Although described here as controlling only one adjustable delay circuit 102 , a single delay adjusting circuit 60 may be used to adjust any or all of the adjustable delay circuits within a memory chip, thereby controlling the data delivery time at any or all of the DQ pads on the memory chip.
The operation of the delay adjusting circuit 60 will now be described. In operation, one of the four delay times is selected through the states of signals A and B, as shown in the chart in FIG. 4 B. If A and B are each connected to respective adjustable impedance circuits 96 that are BLOWN, both A and B will be HIGH, indicated as “1” in FIG. 4 B. This places the passgates 82 , 86 , and 90 in a passing state. Because the passgates 86 and 90 are passing, the signal CLKDOR* passes through the delay gate 76 having a delay of 1.5, and through the passgates 86 and 90 to the output terminal 95 . The CLKDOR* signal also passes through the delay gate 72 , having no delay and through the passgate 82 , but is blocked at the passgate 88 , which is in a blocking state by virtue of a HIGH B signal and a LOW signal received from the inverter 94 . By selecting the states of the signals A and B (by selectively adjusting the impedance circuits 96 ), it is easy to adjust the time delay of a clock signal input to the delay adjusting circuit 60 . In one embodiment, the delay time selected by keeping the adjustable impedance circuits 96 in their natural state will be the delay most likely to provide the greatest tolerances for both T AC and T OH . In FIG. 4A this desired delay is 1.0. In this way, the majority of the memory chips will pass the T AC and T OH specifications without further adjustment, saving labor and equipment costs. Only in the extraordinary case will the delay need adjustment. Although shown here with only two columns of passgates controlled by the signals A and B, it is apparent that a greater selection of delay times can be made available with the addition of more control signals and more passgates, or that the passgates could have a different configuration. For instance, eight different delay times are efficiently selectable if three control signals are used, with three columns, one each containing two, four and eight passgates.
Although the delay adjusting circuit 60 is shown after the clock circuitry 15 , it can appear in many locations in a synchronized memory circuit, some of which are illustrated in FIG. 3 . For instance, the delay adjusting circuit 60 can appear directly before the clock circuitry 15 . If the delay adjusting circuit 60 is placed after the passgates 24 and 26 , the delay adjusting circuit must be implemented in pairs because the data has two separate paths. Only one delay adjusting circuit 60 is needed if it is located between an output terminal 37 and the DQ pad 40 . Of course, there are other locations where the delay adjusting circuit 60 could be placed, as long as it is between the clock signal input 7 and the DQ pad 40 .
A synchronous dynamic random access memory (SDRAM) 200 using the adjustable time delay circuit 102 of FIG. 3 is shown in FIG. 6 . The SDRAM 200 has a control logic circuit 202 receiving a clock signal CLK and a clock enable signal CKE. In the SDRAM 200 , all operations are referenced to a particular edge of an internal clock signal ICLK and a data read clock CLKDOR*, both generated from the clock signal CLK. The edge of the ICLK signal that is used is typically the rising edge, while the data read operations are referenced to the falling edge of the CLKDOR*, as known in the art. The delay adjusting circuit 60 is preferably included in the control logic 202 to adjust the timing of the data read clock CLKDOR* relative to the clock signal CLK. In practice, a variety of internal clock signals may be generated from the clock signal CLK, and only some of them may have their timing controlled by the delay adjusting circuit 60 . However, in the interest of brevity, only two internal clock signals, ICLK and CLKDOR* are shown. The control circuit 202 further includes a command decode circuit 204 receiving a number of command signals on respective external terminals of the SDRAM 200 . These command signals typically include a chip select signal {overscore (CS)}, write enable signal {overscore (WE)}, column address strobe signal {overscore (CAS)}, and row address strobe signal {overscore (RAS)}. Specific combinations of these signals define particular data transfer commands of the SDRAM 200 such as ACTIVE, PRECHARGE, READ, and WRITE as known in the art. An external circuit, such as a processor or memory controller generates these data transfer commands to read data from and to write data to the SDRAM 200 .
The SDRAM 200 further includes an address register 206 operable to latch an address applied on an address bus 208 , and output the latched address to the control circuit 202 , a column address latch 210 , and a row address multiplexer 212 . During operation of the SDRAM 200 , a row address with a bank address BA and a column address with the bank address are sequentially latched by the address register 206 under control of the control circuit 202 . In response to the latched bank address BA and row address, the control circuit 202 controls the row address multiplexer 212 to latch and output the row address to one of a row address latch 214 and 216 . The row address latches 214 and 216 , when activated, latch the row address from the row address multiplexer 212 and output this latched row address to an associated row decoder circuit 222 and 224 , respectively. The row decoder circuits 222 and 224 decode the latched row address and activate a corresponding row of memory cells in memory banks 218 and 220 , respectively. The memory banks 218 and 220 each include a number of memory cells (not shown) arranged in rows and columns, each memory cell operable to store a bit of data and having an associated row and column address.
When a column address and bank address BA is applied on the address bus 208 , the column address is latched by the address register 206 under control of the control circuit 202 , and output to a column address latch 210 , which latches the column address and in turn outputs the column address to a burst counter circuit 226 . The burst counter circuit 226 operates to develop sequential column addresses beginning with the latched column address when the SDRAM 200 is operating in a burst mode. The burst counter 226 outputs the developed column addresses to a column address buffer 228 , which in turn outputs the developed column address to a pair column decoder circuits 230 and 231 . The column decoder circuits 230 and 231 decode the column address and activates one of a plurality of column select signals 232 corresponding to the decoded column address. The column select signals 232 are output to sense amplifier and I/O gating circuits 234 and 236 associated with the memory banks 218 and 220 , respectively. The sense amplifier and I/O gating circuits 234 and 236 sense and store the data placed on the digit lines 235 and 237 , respectively, by the memory cells in the addressed row and to thereafter couple the digit lines 235 or 237 corresponding to the addressed memory cell to an internal data bus 238 . The internal data bus 238 is coupled to a data bus 240 of the SDRAM 200 through either a data input register 242 or a data output register 244 . In the preferred embodiment, the adjustable time delay circuit 102 is coupled to the data output register 244 . This circuit is used to adjust the time data is presented to the data bus in reference to the clock signal CLK. A data mask signal DQM controls the circuits 234 and 236 to avoid data contention on the data bus 240 when, for example, a READ command is followed immediately by a WRITE command, as known in the art.
In operation, during a read data transfer operation, an external circuit, such as a processor, applies a bank address BA and row address on the address bus 208 and provides an ACTIVE command to the command decode circuit 204 . This applied address and command information is latched by the SDRAM 200 on the next rising edge of the clock signal CLK, and the control circuit 202 thereafter activates the addressed memory bank 218 or 220 . The supplied row address is coupled through the row address multiplexer 212 to the row address latch 214 or 216 associated with the addressed bank, and this row address is thereafter decoded and the row of memory cells in the activated memory bank 218 or 220 is activated. The sense amplifiers in the sense amplifier and I/O gating circuit 234 or 236 sense and store the data contained in each memory cell in the activated row of the addressed memory bank 218 or 220 .
The external circuit thereafter applies a READ command to the command decode circuit 204 including a column address and bank address BA on the address bus 208 , both of which are latched on the next rising edge of the clock signal CLK. The latched column address is then routed through the circuits 210 , 226 , and 228 to the column decoder circuit 230 under control of the control circuit 204 . The column decoder 230 decodes the latched column address and activates the column select signal 232 corresponding to that decoded column address. In response to the activated column select signal 232 , the sense amplifier and I/O gating circuit 234 or 236 transfers the addressed data onto the internal data bus 238 , and the data is then transferred from the internal data bus 238 through the data output register 244 and onto the data bus 240 where it is read by the external circuit.
During a write data transfer operation, after activating the addressed memory bank 218 or 220 and the addressed row within that bank, the external circuit applies a WRITE command to the command decode circuit 204 including a column address and bank address BA on the address bus 208 and data on the data bus 240 . The WRITE command, column address, and data are latched respectively into the command decode circuit 204 , address register 206 , and data input register 242 on the next rising edge of the clock signal CLK or an internal clock signal not generated by the delay adjusting circuit 60 . The data latched in the data input register 242 is placed on the internal data bus 238 , and the latched column address is routed through the circuits 210 , 226 , and 228 to the column decoder circuit 230 under control of the control circuit 204 . The column decoder 230 decodes the latched column address and activates the column select signal 232 corresponding to that decoded address. In response to the activated column select signal 232 , the data on the internal data bus 238 is transferred through the sense amplifier and I/O gating circuit 234 or 236 to the digit lines 235 or 237 corresponding to the addressed memory cell. The row containing the addressed memory cell is thereafter deactivated to store the written data in the addressed memory cell.
Although the adjustable time delay circuit 102 has been described as being used in the SDRAM 200 , it will be understood that it may also be used in other types of integrated circuits such as synchronous graphics RAM (SGRAM), or synchronous static RAM (synchronous SRAM). Those skilled in the art realize the differences between SDRAM and other types of memories, and can easily implement the adjustable time delay circuit 102 .
FIG. 7 is a block diagram of a computer system 300 including the SDRAM 200 of FIG. 5 . The computer system 300 includes a processor 302 for performing various computing functions, such as executing specific software to perform specific calculations or tasks. Coupled to the processor 302 is a synchronous SRAM circuit 303 , used for a memory cache or other memory functions. In addition, the computer system 300 includes one or more input devices 304 , such as a keyboard or a mouse, coupled to the processor 302 to allow an operator to interface with the computer system 300 . Typically, the computer system 300 also includes one or more output devices 306 coupled to the processor 302 , such output devices typically being a printer or a video terminal. One or more data storage devices 308 are also typically coupled to the processor 302 to store data or retrieve data from external storage media (not shown). Examples of typical data storage devices 308 include hard and floppy disks, tape cassettes, compact disk read-only memories (CD-ROMs), and digital videodisk read-only memories (DVD-ROMs). The processor 302 is typically coupled to the SDRAM 200 and to the synchronous SRAM 303 through a control bus, a data bus, and an address bus to provide for writing data to and reading data from the SDRAM and synchronous SRAM. A clocking circuit (not shown) typically develops a clock signal driving the processor 302 , SDRAM 200 , and synchronous SRAM 303 during such data transfers.
It is to be understood that even though various embodiments and advantages of the present invention have been set forth in the foregoing description, the above disclosure is illustrative only, and changes may be made in detail, and yet remain within the broad principles of the invention. Therefore, the present invention is to be limited only by the appended claims.
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A circuit for adjusting a time when data is delivered to a data terminal with respect to an external clock signal includes a data passing circuit and a delay adjusting circuit. The delay adjusting circuit accepts a plurality of control signals each arranged to control passgates arranged in columns, with one column being controlled by a respective one of the control signals. A clock signal passes in parallel manner through a variety of delay gates, and each delay gate is coupled in series with one of the passgates. By selecting a path through desired passgates, one delay path is selected and the delay time added to the clock signal. This delayed clock signal is used to control the data passing circuit, which controls when data is output to the output terminals relative to the original clock signal. The control signals are created by selectively coupling or decoupling the control signals from a static voltage, and fuses or antifuses can be used to facilitate this coupling or decoupling.
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TECHNICAL FIELD
The present invention relates to a torque splitting device for changing the torque distribution ratio to right and left axles depending on the operating condition of the vehicle.
BACKGROUND OF THE INVENTION
The applicant has previously proposed, for instance in Japanese patent laid-open publication No. 8-21492 which corresponds to the U.S. patent application Ser. No. 08/497,557 filed Jun. 30, 1995, a torque splitting device which, provided in parallel with a conventional differential device, controls the simulated rolling resistance to each of the right and left or front and rear axles and boosts the rotational speed of the axle encountering a lower rolling resistance. Thereby, the torque distribution ratio to the right and left axles can be positively changed depending on the steering wheel steering angle and the vehicle speed to the end of improving the steering performance of the vehicle. The contents of the above mentioned United States patent application are hereby incorporated in this application by reference.
As illustrated in FIG. 9, this previously proposed torque splitting device T comprises an oil pressure pump 32 producing an output pressure that depends on the vehicle speed, a regulator Re for adjusting the output pressure to a prescribed level, a pair of wet hydraulic multi-disk clutches Ca and Cd for producing simulated rolling resistances, a pressure regulating valve 30 consisting of a linear solenoid valve for determining a torque distribution ratio for the right and left (or front and rear) wheels according to the turning radius or the road resistance, and controlling the engagement forces of the clutches Ca and Cd so as to achieve a desired torque distribution ratio by adjusting the oil pressure for each of the clutches to a target value, an electronic control unit 29 for computing the target oil pressures, and controlling the electric current for the pressure regulating valve 30, and a planetary gear mechanism P which is connected to the wet hydraulic multi-disk clutches Ca and Cd and actually distributes the torque. The output of the engine E forwarded to the torque splitting device T via the transmission TM can be thus appropriately distributed to the right and left (or front and rear) axles 5L and 5R depending on the operating condition of the vehicle.
Thus, by appropriately distributing the engine drive torque to the right and left driven wheels, it is possible to produce a yaw moment which assist the vehicle to go into a turn while involving a relatively small side slip angle of the front wheels. However, when a front wheel drive vehicle does a relatively tight turn while applying an engine brake to the driven wheels or the front wheels, because the side slip angle of the front wheels increases, a moment is produced which tends to turn the vehicle inward with respect to the turning circle, or an oversteer tendency, is produced as is well known in the art. Conversely, when a front drive vehicle accelerates while turning, the vehicle tends to demonstrate an understeer tendency.
However, when the vehicle is equipped with a torque splitting device, it is possible to eliminate such a tendency by appropriately controlling the torque distribution to the right and left front wheels. This is generally advantageous because most vehicle operators do not particularly prefer the vehicle to show different turning behaviors depending on if the vehicle is accelerating, decelerating, or traveling at constant speed.
However, there are also those vehicle operators who prefer to retain the behavior of the conventional front drive vehicle when turning. In particular, the vehicle operator may rely on the oversteer tendency of the vehicle when going into a tight turn under an engine brake condition or, in some cases, may even deliberately release the accelerator pedal and produce an engine brake condition to force the vehicle to make a sharper turn than otherwise possible.
BRIEF SUMMARY OF THE INVENTION
In view of such problems of the prior art and the recognition by the inventors, a primary object of the present invention is to provide a torque splitting device which allows the vehicle to make a turn exactly as a steering wheel is turned without involving any significant side slip angle of the front wheels.
A second object of the present invention is to provide a torque splitting device which makes the vehicle equipped with the device acceptable to a large majority of vehicle operators.
A third object of the present invention is to provide a torque splitting device which would not create an impression of an understeer tendency when such a tendency is not desirable.
A fourth object of the present invention is to improve the handling of a torque splitting device with a minimum modification.
According to the present invention, these and other objects can be accomplished by providing a torque splitting device for distributing an input torque applied to an input member to a pair of output members adapted to be coupled with right and left driven wheels of a vehicle at an adjustable distribution ratio, comprising: a torque splitting mechanism including at least one hydraulically actuated clutch for controlling a torque distribution ratio to the two output members; an oil circuit for supplying actuating oil to the clutch including a regulating valve for controlling a pressure of the actuating oil supplied to the clutch; means for detecting a drive condition of the vehicle; and a control unit for controlling the torque distribution ratio via the regulating valve according to a prescribed control schedule; the control unit being adapted to change the torque distribution ratio according to an output from the drive condition detecting means when the vehicle is turning. The drive torque detecting means may consist of an actual torque sensor, a throttle opening sensor, or an intake manifold pressure sensor, among other possibilities. The torque distribution ratio may be achieved simply by changing a speed transmission ratio from the input member to at least one of the output members.
According to this arrangement, the understeer and oversteer condition of the vehicle while turning a curve can be controlled at will, and a desired property can be achieved simply by changing the relationship between the vehicle drive condition and the torque distribution ratio. For instance, when the vehicle is turning, the input torque may be more preferentially distributed to one of the output members coupled with an outer wheel of the vehicle over the other output member coupled with an inner wheel of the vehicle when a positive drive condition is detected than when no drive condition is detected. Thus, the understeer condition which is otherwise produced can be appropriately controlled.
Also, when the vehicle is turning, the input torque may be more preferentially distributed to one of the output members coupled with an inner wheel of the vehicle over the other output member coupled with an outer wheel of the vehicle when a negative drive condition is detected than when no drive condition is detected. Thus, the oversteer condition which is otherwise produced can be appropriately controlled.
Because a slight oversteer condition when the vehicle turns a curve under a negative drive condition is not necessarily undesirable, and may even be desirable in some cases, the control unit may further include a drive torque modifying unit which modifies an output of the drive condition detecting means to a substantially zero value when a negative drive condition is detected. In particular, when the vehicle changes from a positive drive condition to a negative drive condition while tuning a curve, the oversteer condition associated with the negative drive condition occurs with a certain time delay. Therefore, it is desirable not to cancel the preferential torque distribution, which has been controlling the understeer tendency of the vehicle under the positive drive condition, too abruptly because it would cause an apparent understeer condition which could alarm the vehicle operator. Therefore, the control unit may further include a first order delay unit which produces a first order delay in an output of the drive torque modifying unit, and a comparison unit which produces a greater one of outputs of the drive torque modifying unit and the first order delay unit as an output from the drive condition detecting means . To select the time constant for this first order time delay in such as manner as to be appropriate at all times, it is deisrable if the time constant takes a smaller value when a lateral acceleration of the vehicle is larger and/or when the vehicle speed is higher.
BRIEF DESCRIPTION OF THE DRAWINGS
Now the present invention is described in the following with reference the appended drawings, in which:
FIG. 1 is a longitudinal sectional view of a torque splitting device for distributing an input torque to right and left axles of a vehicle embodyiny the present invention;
FIG. 2 is a longitudinal sectional view of a differential device which is connected to the torque splitting device of FIG. 1;
FIG. 3 is a skeleton diagram of a power transmission system of a front engine, front drive vehicle which combines the torque splitting device and the differential device shown in FIGS. 1 and 2, repsectively;
FIG. 4 is a view similar to FIG. 3 illustrating the control action during a right turn;
FIG. 5 is a view similar to FIG. 3 illustrating the control action during a left turn;
FIG. 6 is a block diagram of the control arrangement of the torque splitting device;
FIGS. 7 and 8 are diagrams for describing the control action of the control arrangement; and
FIG. 9 is a block diagram showing the overall structure of a previous proposed torque splitting device to which the present invention is applied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First of all, the torque splitting device to which the present invention is applied is described with reference to FIGS. 1 and 2. This torque splitting device T is connected to an output shaft 1 of a transmission to which the engine output is transmitted, via a differential device D which is illustrated in FIG. 2.
The differential device D consists of a double pinion type planetary gear mechanism, and comprises a driven member 2 which includes an external teeth gear 2ex meshing with an output gear 3 provided on an axial end of the output shaft 1 of the transmission, and an internal teeth gear 2in formed integrally with the external teeth gear 2ex, differential casing halves 4L and 4R which are joined together by threaded bolts interposing the driven member 2 between them, right and left output shafts 5L and 5R which are rotatably passed through central holes of the differential casing halves 4L and 4R, respectively, a sun gear 6 which is spline coupled to an axial end of the left output shaft 5L, outer pinions 7ex which each mesh with the internal teeth gear 2in of the driven member 2 and rotate around both itself and the sun gear 6, inner pinions 7in (see FIG. 3; the inner pinions 7in do not appear in FIG. 1) which each mesh with the outer pinions 7ex and the sun gear 6 and rotate around both itself and the sun gear 6, and right and left planetary carriers 8L and 8R which rotatably support the inner and outer pinions 7in and 7ex. Central parts of the right and left differential casings 4L and 4R are supported by a transmission housing 9 for instance by roller bearings. The right planetary carrier 8R pivotally supports the sun gear 6 via a needle bearing, and is spline coupled to an axial end of the right output shaft 5R. The left planetary carrier 8L surrounds the left output shaft 5L, and is spline coupled to the right end of a sleeve 10 passed through the central hole of the left differential casing 4L.
In this differential device D, the driven member 2 serves as an input element, and the sun gear 6 which serves as one of two output elements, is connected to the left front wheel WFL via the left output shaft 5L while the right planetary carrier 8R which serves as the other output element is connected to the right front wheel WFR via the right output shaft 5R. A drive shaft equipped with a known isokinetic coupling is interposed between the left output shaft 5L and the left front wheel WFL, and between the right output shaft 5R and the right front wheel WFR.
The torque splitting device T consists of a planetary gear mechanism P, and clutches Ca and Cd for acceleration and deceleration each consisting of a wet hydraulic multi-plate clutch.
The planetary gear mechanism P of the torque splitting device T comprises a planetary carrier 12 pivotally supported by a casing 11 so as to surround the left output shaft 5L, a plurality (for instance four) of triple pinion members 16 which each integrally combine a first pinion 13, a second pinion 14 and a third pinion 15, and pivotally supported along a circle concentric to the center of the planetary carrier, a first sun gear 17 pivotally supported around the left output shaft 5L and meshes with the first pinion 13, a second sun gear 18 which is spline coupled to the outer circumference of the left output shaft 5L at a point immediately left of the first sun gear 17, and a third sun gear 19 which is integral with an inner plate retaining member 21 of the acceleration clutch Ca and meshes with the third pinion 15. The inner plate retaining member 21 is pivotally supported around the left output shaft 5L.
The first sun gear 17 is spline coupled to the left end of the sleeve 10 which is in turn spline coupled to the left planetary carrier 8L of the differential device D so as to integrally rotate with the planetary carriers 8L and 8R and the right output shaft 5R of the differential device D.
The acceleration clutch Ca couples inner plates 22, which are axially slidably engaged by the inner plate retaining member 21 pivotally mounted on the left output shaft 5L, with outer plates 23, which are axially slidably engaged by an inner surface of the casing 11, with the thrust force of an annular hydraulic piston 24, and performs the function of arresting the rotation of the third sun gear 19 which is integral with the inner plate retaining member 21.
The deceleration clutch Cd couples inner plates 26, which are axially slidably engaged by an inner plate retaining member 25 formed in the planetary carrier 12, with outer plates 27, which are axially slidably engaged by an inner surface of the casing 11, with the thrust force of an annular hydraulic piston 28, and performs the function of arresting the rotation of the triple pinion members 16, which are pivotally supported by the planetary carrier 12, around the sun gears.
The engagement forces of the acceleration and deceleration clutches Ca and Cd are controlled by the oil pressure supplied thereto from a gear pump 32, driven by a spur gear 31 spline coupled to the left output shaft 5L, via an oil pressure circuit including a pressure regulating valve 30. The pressure regulating valve 30 is controlled by an electronic control unit 29 receiving a vehicle speed VW and a steering angle θs as data.
Now the operation of this device is described in the following with reference to FIGS. 3 to 5.
When the vehicle is traveling straight ahead, the deceleration and acceleration clutches Cd and Ca are both disengaged. As a result, the planetary carrier 12 and the third sun gear 19 of the torque splitting device T are both allowed to move freely, and the left output shaft 5L, the right output shaft 5R, the planetary carrier 8 of the differential device D, and the planetary carrier 12 of the torque splitting device T all move in a body. As indicated by the shaded arrow in FIG. 3, the output torque of the engine is evenly distributed to the right and left front wheels WFL and WFR via the differential device D.
When the vehicle is turning right, as shown in FIG. 4, the deceleration clutch Cd is engaged so that the planetary carrier 12 is joined with the casing 11, and is thereby kept stationary. Because the left front wheel WFL which is integral with the left output shaft 5L (or the planetary carrier 8L of the differential device D) is coupled with the right front wheel WFR which is integral with the right output shaft 5R (or the planetary carrier 8R of the differential device D) via the meshing between the second sun gear 18 and the second pinion 14, and the meshing between the first pinion 13 and the first sun gear 17, the rotational speed NL of the left front wheel WFL is increased in speed over the rotational speed NR of the right front wheel WFR.
NL/NR=(Z4/Z3) (Z1/Z2) (Equation 1)
where Z1: number of teeth of the first sun gear 17
Z2: number of teeth of the first pinion 13
Z3 : number of teeth of the second sun gear 18
Z4: number of teeth of the second pinion 14
As described above, when the rotational speed NL of the left front wheel WFL is increased in speed over the rotational speed NR of the right front wheel WFR, as indicated by the shaded arrow in FIG. 4, a part of the torque distributed to the right front wheel WFR or the inner wheel from the differential device D is transmitted to the left front wheel WFL or the outer wheel.
When the planetary carrier 12 of the torque splitting device T is reduced in speed by partly engaging the deceleration clutch Cd instead of totally preventing the motion of the planetary carrier 12, the rotational speed NL of the left front wheel WFL is increased in speed over the rotational speed NR of the right front wheel WFR by a corresponding amount so that it is possible to change the amount of torque transmission from the right front wheel WFR or the inner wheel to the left front wheel WFL or the outer wheel at will.
When the vehicle is turning left, as shown in FIG. 5, the acceleration clutch Ca is engaged so that the third sun gear 19 which is integral with the inner plate retaining member 21 of the acceleration clutch Ca is kept stationary. As a result, the triple pinion members 16 rotate around the center of the sun gears via the third pinion 15 meshing with the third sun gear 19, and the rotational speed of the planetary carrier 12 is increased over the rotational speed NL of the left front wheel WFL according to the following relationship.
NL/NR=[1-(Z5/Z6) (Z2/Z1)]/[1-(Z5/Z6) (Z4/Z3)](Equation 2)
where Z5: number of teeth of the third sun gear 19
Z6: number of teeth of the third pinion 15
As described above, when the rotational speed NR of the right front wheel WFR is increased in speed over the rotational speed NL of the left front wheel WF, as indicated by the shaded arrow in FIG. 5, a part of the torque distributed to the left front wheel WFL or the inner wheel from the differential device D is transmitted to the right front wheel WFR or the outer wheel. In this case also, it is possible to change the amount of torque transmission from the left front wheel WFL to the right front wheel WFR at will by changing the engagement force of the acceleration clutch Ca.
Now the operation of the electronic control unit 29 embodying the present invention is described in the following with reference to FIGS. 6 and 8.
According to the previously proposed arrangement the torque distribution to the right and left front wheels was determined in such a way that the right and left wheels follow the turning circle without involving any significant side slip angle. However, when the vehicle is accelerating (positive drive torque XG) while turning, there will be an understeer tendency. To offset such a tendency, it may be desirable to shift some of the drive torque of the inner front wheel to the outer front wheel. Conversely when the vehicle is decelerating negative drive torque XG) while making a turn, there will be an oversteer tendency. To offset such a tendency, it may be desirable to shift some of the drive torque of the outer front wheel to the inner front wheel. Thus, the vehicle can follow the turning circle as determined by the steering angle of the steering wheel irrespective of the acceleration or deceleration condition of the vehicle.
However, there are those vehicle operators who would not find such a control action entirely satisfactory. FIG. 6 illustrates the internal arrangement of the control unit 29 which takes into account such a factor as described hereinafter. The control unit 29 receives signals which represent a turning amount (KG) and an actual drive torque (XG). The turning amount KG is given by the following formula.
KG=YG+f.sub.1 (θs×VW) (Equation 3)
where YG lateral acceleration
θs: steering angle
VW: vehicle speed
The actual drive torque XG is modified into a modified drive torque XGF by a drive torque modifying unit 45 as defined by the following formula.
XGF=XG (when XG>0) 0 (when XG≦0) (Equation 4)
By using the modified drive torque XGF instead of the simple drive torque XG in the control of the right and left torque distribution, it is possible to retain the slight oversteer tendency when the vehicle decelerates while turning. This is beneficial because the vehicle operator is able to handle the vehicle more at will. When the vehicle accelerates while turning, the engine drive torque is shifted from the inner wheel to the outer wheel, and the understeer tendency is thereby offset by a suitable torque distribution.
The upper part of FIG. 7 shows a typical pattern of the engine drive torque XG when a vehicle turns a curve. Initially, the vehicle enters the curve while decelerating. Once the vehicle enters the curve at a suitable speed, the vehicle gradually increases the speed. As often the case, this acceleration then turns out to be slightly excessive, and toward the end of the curve, the vehicle again decelerates. For driving comfort, it is desirable to produce a suitable amount of oversteer tendency when the vehicle decelerates while turning because the intention to decelerate is normally due to the anticipated difficulty in completing the turn without swerving outward from the turning circle of the vehicle if the current vehicle speed is maintained.
FIG. 6 illustrates the inner arrangement of the control unit 29. The turning amount KG is supplied to torque distribution ratio computing unit 41, and the modified drive torque XGF is supplied to a drive torque comparing unit 42 and a first order delay unit 43. The output of the first order delay unit 43 is supplied to the drive torque comparing unit 42. The drive torque comparing unit 42 compares the modified drive torque XGF directly supplied thereto with a delayed acceleration drive torque XGF1 supplied thereto via the first order delay unit 43, and forwards the larger of the values of these two signals to the torque distribution ratio computing unit 41 which is connected to an oil pressure/current converter 44 for actually controlling the pressure regulating valve 30 as required.
The comparing process in the drive torque comparing unit 42 is now described in the following with reference to FIG. 7. Suppose that the engine drive torque changes as indicated by the upper part of FIG. 7 during a turn. As indicated in the lower part of FIG. 7, the modified drive torque XGF is zero when the actual drive torque XG is zero or less, and is otherwise equal to the actual drive torque XG. The output XGF1 of the first order delay unit 43 changes as indicated by the double chain dot line in the lower part of FIG. 7. The drive torque comparing unit 42 compares the modified drive torque XGF and the delayed modified drive torque XGF1, and produces the larger of these two values as an effective drive torque XGFB.
The torque distribution ratio computing unit 41 computes a torque distribution ratio TOBJ with a mathematical function of f 2 (KG, XGFB) of the turning amount KG directly supplied thereto, and the effective drive torque XGFB supplied from the drive torque comparing unit 42. The obtained torque distribution ratio TOBJ is converted into an oil pressure target value by the oil pressure/current converter 44 for determining the state of the pressure regulating valve 30.
Thus, according to this control arrangement, the torque splitting device is controlled as described in the following. When the vehicle decelerates while turning, the torque splitting device operates as if the vehicle were turning at a constant speed, disregarding the deceleration of the vehicle. When the vehicle accelerates while making a turn, the drive torque is somewhat shifted from the inner wheel to the outer wheel to offset the understeer tendency which may be otherwise produced. When the vehicle starts accelerating either from a deceleration condition or a constant speed condition, it is desirable to shift the drive torque from the inner wheel to the outer wheel as quickly as possible. Therefore, the torque comparing unit 42 forwards the modified drive torque XGF as the effective XGFB to the mathematical function f 2 (KG, XGFB). However, when the vehicle starts decelerating from an acceleration condition, it is not desirable to cancel the shifting of the drive torque from the outer wheel to the inner wheel too quickly. This is because if the torque distribution which has been assisting the turning tendency of the vehicle is abruptly removed, this creates a phase of apparent understeer condition because the oversteer condition associated with the deceleration of the vehicle while turning occurs with a certain time delay. Therefore, according to this embodiment, the torque comparing unit 42 forwards the delayed modified drive torque XGF1 as the effective drive torque XGFB to the mathematical function f 2 (KG, XGFB).
Suppose a situation where the vehicle enters a curve while decelerating, and turns the curve while accelerating as recommended by any experienced vehicle operator. While turning, the vehicle operator may realize that the vehicle speed may be excessive to safely complete the turning of the curve, and decelerates. According to the control unit 29 of this embodiment, the vehicle entering the curve is given a slight oversteer tendency, and maintains a neutral steer tendency during acceleration. When the vehicle decelerates in the midst of making the turn, it is essential not to create any understeer tendency even if it is a transient occurrence in view of avoiding the swerving of the vehicle outward from the intended turning circle of the vehicle. The control unit therefore employs the first order delay to avoid any abrupt canceling of the shifting of the drive torque from the inner wheel to the outer wheel upon the change from the accelerating phase to the decelerating phase.
When carrying out the above described control action, the engagement forces of the engagement clutches may be continually controlled between a zero engagement state and a full engagement state. This can be accomplished either by analog control of the oil pressure or by pulse width control or other digital control of the oil pressure.
The time constant TXG used by the first order delay unit 43 may be determined from a data map which relates the time constant with the lateral acceleration GY of the vehicle, for instance as indicated in FIG. 8. This data map is defined by three different curves KT1, KT2 and KT3 depending on the vehicle speed. The curves KT1, KT2 and KI3 represent high, medium and low speed ranges, respectively. As shown by the diagram of FIG. 8, as the vehicle speed increases, the time constant becomes generally smaller or the canceling of the shifting of the drive torque becomes generally quicker. This is desirable because as the vehicle speed increases, the onset of the oversteer condition following the deceleration while making a turn is relatively more immediate. Also, as the lateral acceleration GY increases, the time constant becomes generally smaller. This is desirable because a large lateral acceleration means an accordingly extreme drive condition, and the vehicle operator needs and may well expect a quick recovery of an oversteer tendency all the more.
Although the present invention has been described in terms of preferred embodiments thereof, it is obvious to a person skilled in the art that various alterations and modifications are possible without departing from the scope of the present invention which is set forth in the appended claims.
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In a torque splitting device for distributing an input torque applied to an input member to a pair of output members adapted to be coupled with right and left driven wheels of a vehicle at an adjustable distribution ratio, the distribution ratio is determined in such a way that the understeer and oversteer tendencies of the vehicle under a positive or negative drive condition while turning a curve is appropriately controlled. In particular, it is highly desirable to prevent an understeer tendency from appearing while turning a curve. Therefore, when the vehicle is under a positive drive condition while tuning a curve, a yaw moment is produced by an appropriate torque distribution which assists the vehicle to turn in such a way that the understeerg condition is canceled. Furthermore, when the vehicle moves on from a positively drive condition to a negative drive condition while turning a curve, a slight oversteer tendency is produced with a minimum time delay so as to avoid any transient phase of an understeer condition from appearing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from German National Patent Application No. 10 2013 008 107.6, filed May 11, 2013, entitled “Verfahren zum Betreiben einer Offenend-Rotorspinnmaschine, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a method for operating an open-end rotor spinning machine, having a plurality of workstations, usually large in number, which in each case have a spinning device with a rotor housing, to which negative pressure can be applied, in which a spinning rotor revolves at a high rotational speed, for producing a yarn, as well as a winding device for producing a cross-wound bobbin, wherein the connection of the workstations to a central negative pressure supply which can be selectively switched off.
BACKGROUND OF THE INVENTION
Open-end rotor spinning machines have been known for a long time and generally consist of a large number of similar workstations arranged next to one another in a row. In addition, they have a central control mechanism as well as a negative pressure system particular to the spinning machine Each of these workstations has a spinning and a winding device, on which a fiber band (commonly referred to as a sliver) presented in a spinning can is spun to form a yarn and is wound to form a cross-wound bobbin.
The fiber band is fed by means of a fiber band feed cylinder to an opening cylinder which, with its clothing, opens the fiber band into individual fibers and transports them to a fiber guide channel of the spinning box. The fiber transport is assisted by negative pressure existing in the rotor housing, which produces an air stream in the fiber guide channel, releases the fibers from the opening clothing and conveys them in a targeted manner into the spinning rotor by means of a so-called channel plate adapter. Owing to the centrifugal acceleration of the spinning rotor, the fibers slide into a collecting groove of the spinning rotor, are collected there, are drawn off axially by a withdrawal nozzle in the rotational axis of the rotor and thus rotated to form a yarn that is wound onto a cross-wound bobbin.
After a stoppage of the rotor spinning machine or after a yarn break, the spinning process has to be resumed. For reconnecting the trailing end of yarn previously formed to fibers in the spinning rotor, called piecing, the trailing yarn end is guided counter to the yarn withdrawal direction into the yarn withdrawal tube of the spinning chamber and suctioned in by the negative pressure in the rotor housing. The cross-wound bobbin is pivoted down, in other words brought into contact with a bobbin drive roller again and as soon as the yarn end reaches the collecting groove of the spinning rotor or the fiber ring located therein, the yarn end breaks open the fiber ring and the spinning process can be continued.
An open-end rotor spinning machine, which, in the suction line for producing the negative spinning pressure in the rotor housing, has a valve with rapid venting, is disclosed by European Patent Publication EP 0 529 312 B1. The suction of the rotor housing is interrupted before piecing by means of the valve. As a result, the fibers are not suctioned, as usual during the spinning process, through the fiber guide channel, but through the suction opening of the opening roller. With the introduction of the yarn end into the spinning rotor and by opening the valve, the rotor housing again has negative pressure applied. The suction through the suction opening of the opening roller is ended so as to be synchronized with this with respect to time. A more uniform yarn piecing is to be produced by this deflection of the fiber stream during the piecing process.
German Patent Publication DE 10 2006 037 849 A1 discloses an open-end spinning machine and a method for controlling an open-end spinning machine during a setting process when repiecing a yarn or after a yarn break. Proceeding from the fact that during repiecing after the closing of the housing, the rotor interior is cleaned by means of so-called rinsing air of subsequently introduced impurities that have accumulated there, that each spinning station requires its own rinsing air guide for this step and that the automatic piecing mechanisms or maintenance mechanisms additionally must have corresponding connections to introduce the rinsing air, a repiecing of the yarn is to be made possible with reduced outlay with respect to the device and method.
For this purpose, according to German Patent Publication DE 10 2006 037 849 A1, upon a stoppage of the fiber band feed or after a predetermined time period, the negative pressure present in the housing is immediately interrupted. This results in the prevention of the fiber band end being drawn by the air, which continues to flow in, to the opening mechanism and prevents the occurrence of an undesired suctioning in of impurities before the housing of the spinning station is closed. In addition, energy can be saved in this manner as a considerable quantity of additional air is suctioned into the machine through the opened housing when negative pressure is present, which would in turn lead to a pressure increase within the pressure systems.
The drawback in the methods and devices according to the prior art, is, however, that the rotor housings of the individual workstations permanently have negative pressure applied up until the piecing process or the cleaning process connected therewith.
This has a negative effect quite particularly after a restart of the machine or run up after a power failure. As all the workstations have negative pressure applied and additional mechanisms, such as for example, the suction nozzle for grasping the upper yarn or a pneumatic yarn store, which also require negative pressure, are used for piecing, the negative pressure available overall is reduced. Therefore, in a rotor spinning machine with self-sufficiently piecing spinning stations, only a limited number of the spinning stations, e.g., only 12 stations, can repiece simultaneously, as the negative pressure is not sufficient for piecing at further workstations, including the additional mechanisms necessary for this process.
SUMMARY OF THE INVENTION
Proceeding from the aforementioned prior art, the invention is based on the object of developing a method, which optimizes the negative pressure consumption at an open-rotor spinning machine.
This object is achieved by a method for operating an open-end rotor spinning machine having a large number of workstations, which in each case have a spinning device with a rotor housing, to which negative pressure can be applied, in which a spinning rotor revolves at a high rotational speed, to produce a yarn, as well as a winding device to produce a cross-wound bobbin, wherein the connection of the workstations to a central negative pressure supply can be switched off To achieve the object according to the present invention, the application of negative pressure to the rotor housing is limited to the spinning devices which are producing yarn as well as the spinning devices which are repiecing. Additional features of the invention provide further advantageous configurations as described further herein. The advantages achieved by the invention consist, in particular, in that the negative pressure necessary for spinning is only provided for the spinning devices of the individual workstations when the respective workstation is producing yarn or a yarn is repieced.
Previously the procedure in practice was that the negative pressure was fed constantly to all spinning devices, regardless of the fact of whether the spinning device was producing yarn. As, however, some of the spinning devices are often not producing, for example because of yarn interruptions, a cross-wound bobbin change or because not all the workstations are occupied, the negative pressure supply according to the prior art is ineffective.
In particular after a machine start or run up after a power failure, the negative pressure for spinning is exclusively required for the workstations that are to be pieced and those already producing.
When applying the present invention, the machine can be run up more quickly. As exclusively the spinning stations that are actually also piecing have negative pressure applied, more spinning stations can now be simultaneously pieced according to the invention. While, during a machine run-up, about 12 piecing stations could previously be pieced simultaneously, with the method according to the invention now more than 20 spinning stations can be pieced simultaneously. In this manner, the useful effect of the open-end rotor spinning machine is reached more quickly.
Furthermore, an optimized negative pressure consumption adapted to need is produced for an open-end rotor spinning machine. By optimizing the suction power, the energy consumption and therefore the costs connected therewith can be reduced without impairing the productivity of the machine or the yarn quality. Particularly at present, when energy costs make up a not insignificant proportion of the operating costs, reducing the consumption is an important instrument to be able to produce more economically. In addition the lower energy consumption is environmentally friendly.
According to a further aspect of the invention, it is provided in an advantageous embodiment that the control of the entire machine negative pressure takes place depending on the number of workstations that are supplied with negative pressure.
By means of the valve in the suction line for producing the negative spinning pressure in the rotor housing, the entire suctioning-in cross-section of the air system is limited to the necessary amount, which in turn leads to an increase in the system negative pressure. With corresponding control, this increased negative pressure can be reduced again to a previously adjusted pressure value by reducing the rotational speed of the fan. The rotational speed reduction leads to an overall reduced power consumption.
As, in particular, the application of negative pressure to the rotor housing may take place individually for each individual workstation or in groups for a plurality of workstations.
Because of these flexible possibilities, an individual stationary workstation can, for example, be removed from the negative pressure application to the rotor housing, although it is surrounded by workstations producing yarn. However, it may also be sensible to switch non-producing groups of workstations. Depending on need, this may be sections or also section sides. If, for example, the open-end rotor spinning machine is producing temporarily only on the workstations of one machine side, the entire side, the workstations of which are stationary, can be excluded from the negative pressure supply. This would, for example, be possible by an additional branching off of the negative pressure channel system that applies negative pressure to the sections or machine sides.
According to a further feature of the invention, it may advantageously also be provided that a direct or a derived signal initiates the application of negative pressure to the rotor housing.
In order to activate the valve to switch off the negative pressure to the rotor housing, either direct signals, such as the report of a “yarn break” or “machine run up” or derived signals, such as, for example, “bobbin lifting” can be processed. With the arrival of a signal of this type, the valve is actuated and the negative pressure is no longer fed to the rotor housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an open-end rotor spinning machine;
FIG. 2 schematically shows, in a side view, an open-end spinning device with a spinning rotor revolving in a rotor housing, to which negative pressure can be applied, and a fiber band opening mechanism, which is connected by a fiber guide channel to the rotor housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically shows a front view of an open-end rotor spinning machine 1 . The open-end rotor spinning machine 1 has a large number of substantially self-sufficient workstations 4 arranged between two end frames 2 and 3 . The ends frames 2 , 3 of this open-end rotor spinning machine 1 , are, as known and therefore not shown in more detail, connected by means of continuous supply and disposal channels, for example a negative pressure channel for supplying the spinning devices 5 arranged in the region of the workstations 4 with negative spinning pressure, an electronic channel for a bus system 13 as well as a cable channel for supplying the workstations 4 with electric energy. The yarn formation and winding mechanisms of the workstations 4 are fixed by means of workstation housings 6 on these supply and disposal channels, which virtually represent the “backbone” of the open-end rotor spinning machine 1 .
The workstation housings 6 releaseably arranged on the supply and disposal channels have, for example, in each case a spinning device 5 , a winding device 7 as well as a control mechanism 8 particular to the workstation.
A negative pressure source 9 particular to the textile machine is arranged in the end frame 3 , while an electric energy supply (not shown) as well as a central control unit 10 of the open-end rotor spinning machine 1 are integrated in the end frame 2 .
The central control unit 10 , which has a computer mechanism 12 with a memory 20 , is connected to the control mechanisms 8 of the individual workstations 4 by means of a bus system 13 or the like. The central control unit 10 furthermore has an operating unit 17 . It is possible by means of the operating unit 17 to input and display parameters, which are required to control the open-end rotor spinning machine 1 and the workstations 4 . For this purpose, the operating unit 17 has a mechanism 11 configured as a keyboard to input the parameters and a display means 19 configured as a screen. The screen 19 can also be configured as a touch screen and thus take on an additional input function. A touch screen of this type is above all suitable to carry out a selection within a menu. The input parameters are stored in the memory 20 of the computer mechanism 12 . Furthermore, the memory 20 contains information as to which parameters are to be adjusted in a specific type of change of the mode of working of the open-end rotor spinning machine 1 . For this purpose, groups of parameters are associated with the types of change of the mode of working.
As can be seen from FIG. 1 , in each case by means of the spinning device 5 , a feed fiber band 14 , which is stored in spinning cans 15 , which are positioned next to one another in a row below the workstations 4 , is spun on the numerous workstations into a yarn 16 , which is then wound on the winding device 7 to form a cross-wound bobbin 18 .
The spinning device of an open-end rotor spinning machine 1 shown in FIG. 2 has the reference numeral 5 overall.
Spinning devices 5 of this type, as known, have a rotor housing 21 , in which the spinning cup 22 of a spinning rotor 23 revolves at a high rotational speed.
The spinning rotor 23 with its rotor shaft 24 is supported in the bearing interstice of a support disc bearing arrangement 25 that is preferably free of axial thrust in the spinning device 5 according to the present embodiment.
The spinning rotor 23 is driven here by a tangential belt 26 along the length of the machine, which is set on the rotor shaft 24 by a tension roller 27 .
The axial positioning of the rotor shaft 24 in the bearing interstice of the support disc bearing arrangement 25 preferably takes place by means of a permanent magnet axial bearing 28 .
In an alternative embodiment, the spinning rotor 23 could obviously also be driven by a single motor and be contactlessly supported, for example, in a permanent magnet bearing arrangement.
The rotor housing 21 that is open per se to the front is closed during spinning operation by a pivotably mounted cover element 29 and connected by means of a suction channel 30 to a negative pressure source 9 , which produces the necessary negative spinning pressure in the rotor housing 21 during the spinning process.
The cover element 29 has a channel plate 31 with a seal 32 preferably positioned in an annular groove.
A channel plate adapter 34 , which has the mouth region of a fiber guide channel 35 , is also, as known, exchangeably arranged in a central bearing receiver 33 of the channel plate 31 .
Furthermore, the channel plate adapter 34 is equipped with a yarn withdrawal nozzle 36 and, on the exit side, with a yarn withdrawal tube 37 .
As is also shown in FIG. 2 , an opening roller housing 39 is fixed on the cover element 29 , which is rotatably mounted to a limited extent about a pivot axis 38 , or the opening roller housing 39 is integrated in the cover element 29 , which, furthermore, has rear bearing brackets 40 , 41 to mount an opening roller 42 or a fiber band feed cylinder 43 .
The opening roller 42 driven here in the region of its wharve 44 by a revolving tangential belt 45 along the length of the machine, while the drive (not shown) of the fiber band feed cylinder 43 preferably takes place by means of a screw gearing arrangement, which is connected to a drive shaft 46 along the length of the machine
In an alternative embodiment, single motor drives for the opening roller 42 and/or the fiber band feed cylinder 43 can obviously also be provided here.
During the regular spinning process, the yarn 16 produced in the spinning device 5 , to which negative pressure is applied, is drawn off by the yarn withdrawal mechanism and then wound on the winding device 7 to form a cross-wound bobbin 18 .
At the same time, the yarn 16 running onto the bobbin is displaced by means of the yarn traversing mechanism (not shown) in such a way that it runs in crossing layers on to the lateral surface of the cross-wound bobbin 18 .
If, for example, a yarn break occurs at one of the workstations 4 of the open-end rotor spinning machine 1 , this is detected by the stop motion, the spinning process is interrupted and the relevant workstation 4 is stopped.
Stated more precisely, the drive of the fiber band feed cylinder 43 is switched off to interrupt the fiber feed to the opening roller 42 and therefore ultimately into the spinning rotor 23 , and the lifting of the cross-wound bobbin 18 from the bobbin drive roller is initiated so that the yarn end 16 cannot mill into the cross-wound bobbin surface 18 .
At the same time, the magnetic valve 50 receives a corresponding signal. Thereupon the magnetic valve 50 switches and the passage between the pressure line 48 and the pressure line 49 , which is connected to a ring line 51 , is opened. The ring line 51 applies excess pressure to a large number of workstations 4 . The compressed air from the ring line 51 flows through the pressure lines 48 and 49 into the squeezing valve 47 and closes the pressure line 30 . The rotor housing 21 no longer has negative pressure applied.
As the yarn end 16 is generally drawn out of the spinning box because of the high winding speed after the yarn break, the yarn end 16 has to be found on the cross-wound bobbin 18 lifted from the bobbin drive roller and some layers have to be unwound therefrom.
Once the yarn end 16 has been prepared for the following piecing and a pieceable fiber tuft has been produced on the yarn end 16 , the yarn end 16 has to be introduced counter to the normal withdrawal direction through the yarn withdrawal tube 37 and the withdrawal nozzle 26 in the direction of the spinning rotor 23 . Once the control mechanism of the workstation 4 has been activated by means of a switching element, not shown, the magnetic valve 50 receives the signal for closing. Thereupon, the squeezing valve 47 opens and the pressure in the pressure line 48 reduces. The rotor housing again has the necessary negative pressure for spinning applied.
At the same time, the fiber band feed cylinder 43 is driven and the fiber band 14 is again fed to the opening roller 42 and therefore the spinning rotor 23 , in the collecting groove of which a fiber ring again forms due to the high centrifugal acceleration. The prepared yarn end 16 slides into the rotor groove.
Negative pressure, which suctions the yam end 16 into the spinning rotor 23 , prevails again in the spinning rotor 23 , so the prepared yam end 16 is connected to the fiber ring in the collecting groove of the spinning rotor 23 . At the same time, the creel lowers until the cross-wound bobbin 18 again rests on the bobbin drive roller and the yam 16 being newly produced is wound on to the cross-wound bobbin 18 .
If a restart of the machine or a run up after a power failure takes place, the control mechanisms of the first twenty workstations 4 are activated by means of switching elements, not shown. Thereupon, the corresponding magnetic valves 50 close at these twenty workstations 4 and the squeezing valves 47 open. The pressure in the pressure line 48 of the respective workstations 4 decreases as a result and the selected workstations 4 have adequate negative pressure applied, so new yarns can be pieced. Once the first twenty workstations 4 have ended the piecing process, the next twenty workstations 4 can have negative pressure applied for piecing.
The present invention has been herein described in relation to an exemplary embodiment or embodiments for purposes of providing an enabling disclosure of the invention. However, it will be understood by persons skilled in the relevant art that the present invention is susceptible of a broader utility and application. Accordingly, it is to be expressly understood that the present invention is not to be construed as limited to the embodiments, features and aspects herein described, but only according to the appended claims.
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A method for operating an open-end rotor spinning machine having a plurality of workstations, usually a large number, each including a spinning device with a rotor housing, to which negative pressure can be applied, in which a spinning rotor ( 23 ) revolves at a high rotational speed, to produce a yarn, as well as a winding device to produce a cross-wound bobbin ( 18 ), wherein the connection of the workstations to a central negative pressure supply can be selectively switched off. The application of negative pressure to the rotor housing is limited to the spinning devices which are producing yarn as well as the spinning devices which are repiecing.
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TECHNICAL FIELD
[0001] The present invention relates to a drive device for an electric vehicle including an electric motor as a drive source, and particularly to a drive device for an electric vehicle of an in-wheel motor type.
BACKGROUND ART
[0002] A conventionally known drive device for an electric vehicle of an in-wheel motor type is made up of an electric motor, a speed reduction unit to which the output of the electric motor is inputted, and a hub unit which is rotationally driven by the speed-reduced output of the speed reduction unit (Patent Literature 1).
[0003] In the drive device for an electric vehicle disclosed in Patent Literature 1, an electric motor is disposed outside the speed reduction unit in the radial direction, and the speed reduction unit in which planetary gear-type units are disposed in two stages in the axial direction is used. The reason why the speed reduction unit is disposed in two stages is for the purpose of increasing the speed reduction ratio.
[0004] A typical configuration of a speed reduction unit of planetary gear type is such that a sun gear is provided on an input shaft in a coaxial manner, and a ring gear is secured around the input shaft in a coaxial manner. A plurality of pinion gears are placed between the sun gear and the ring gear, and a pinion pin that supports each pinion gear is joined to a common carrier. The carrier is integrated with an output member.
[0005] The speed reduction unit is configured such that the pinion gear is caused to revolve while rotating on its axis by the rotation of the input shaft. The rotational speed of the revolving motion is reduced from the rotational speed of the input shaft, and a speed-reduced rotation is transferred to the output member via the carrier. The speed reduction ratio in this case will be Zs/(Zs+Zr). Where, Zs is the number of teeth of the sun gear, and Zr is the number of teeth of the ring gear.
[0006] The input shaft of the speed reduction unit is supported by bearings disposed at two locations in the axial direction, that is, an inboard-side bearing and an outboard side bearing. The inboard-side bearing is attached to a housing of the speed reduction unit, and the outboard-side bearing is attached to the output member of the speed reduction unit. The housing is supported by the vehicle body via the suspension, and the output member is coupled and integrated with an inner member of the hub unit to rotationally drive the vehicle wheel.
[0007] In the above-described drive device for an electric vehicle, the radial load acting on the input shaft of the speed reduction unit is supported by the housing via the inboard-side bearing on the inboard side, and is supported by the output member of the speed reduction unit via the outboard-side bearing on the outboard side.
[0008] On the other hand, the hub unit is joined to a suspension via a knuckle on the vehicle body side in a normal motor vehicle driven by an internal combustion engine.
CITATION LIST
Patent Literature
[0009] Patent Literature 1: Japanese Patent Laid-Open No. 2001-32888
SUMMARY OF INVENTION
Technical Problem
[0010] Regarding the supporting structure of the input shaft of the speed reduction unit, while vibration and impact associated with the rotation of the vehicle wheel are transmitted to the outboard-side end portion of the input shaft via the output member and the outboard-side bearing, vibration and impact of the vehicle wheel will not be directly transmitted to the inboard-side end portion since it is supported by a stationary housing via the inboard-side bearing.
[0011] Moreover, since the hub and the hub bearings that support the output member of the speed reduction unit elastically deform due to the effect of the load imposed on the vehicle wheel from the road, the outboard-side bearing is displaced with respect to the original center of the input and output shafts. On the other hand, the housing that supports the inboard-side bearing is not likely to be affected by the load from the vehicle wheel, and therefore the coaxiality between the two bearings that support the input shaft deteriorates or the inclination therebetween occurs.
[0012] For this reason, eccentric load is likely to act on the inboard-side bearing and the outboard-side bearing, thus causing problems such as decline of rotational accuracy of the input shaft, deterioration of the durability of the bearings, and occurrence of rotation noise of the bearings.
[0013] Moreover, in an electric vehicle, since conventionally a knuckle is a required member in the joining structure between the hub unit and the suspension on the vehicle body side, the number of parts is increased accordingly.
[0014] Thus, it is an object of the present invention to provide a structure that does not require a knuckle on the vehicle body side while improving the rotational accuracy of the input shaft and the durability of the bearings and suppressing the rotation noise of the bearings by improving the supporting structure of the input shaft of the speed reduction unit.
Solution to Problem
[0015] To solve the above-described problems, the present invention provides a drive device for an electric vehicle, comprising: an electric motor; a speed reduction unit including an input shaft driven by output of the electric motor; a hub unit rotationally driven by an output member of the speed reduction unit; and a housing accommodating the electric motor and the speed reduction unit, wherein the input shaft of the speed reduction unit is supported by bearings provided at two locations in the axial direction, the drive device being configured such that the bearings provided at the two locations are both supported by the output member, and the housing is provided with a suspension joining portion.
[0016] According to the above-described configuration, since the bearings for supporting the input shaft at two locations in the axial direction are attached together to the output member, vibration and impact transmitted from the vehicle wheel to the output member will be imposed on both the bearings at the same time and in the same manner. As a result of this, both the bearings are prevented from being subjected to eccentric load. Moreover, the drive device for an electric vehicle can be attached to the vehicle body by directly joining the above-described suspension joining portion to the vehicle body, and thus a knuckle as an intermediate part is not required.
[0017] The output member may be configured to include flanges disposed on both sides in the axial direction of a speed reduction rotational member such as a pinion gear so that the flanges are coupled and integrated with each other by both end portions of a support pin of the speed reduction rotational member being secured to the flanges, and each of the above-described bearings is placed between the inner radial surface of each flange and the input shaft.
[0018] The above-described “speed reduction rotational member” and “support pin” correspond to the “pinion gear” and the “pinion pin” supporting the pinion gear respectively in the case of a planetary gear type. By attaching each bearing to the inner radial surface of each of the above-described flanges, it is possible to realize a configuration in which both bearings are attached together to the output member.
[0019] Since the above-described speed reduction unit has a configuration in which the flanges on both sides are coupled and integrated with each other by support pins, the pinion gear can be placed between both the flanges.
[0020] Thus, the flanges can be configured to be coupled with each other by a bridge so that the flanges can be securely coupled and integrated with each other by the bridge.
[0021] Since both the flanges are securely engaged and integrated with each other by the above-described bridge, the support stiffness of the support pin such as the pinion pin whose both end portions are coupled to both the flanges is increased. Moreover, by providing the bridge at multiple locations of equally spaced positions in a circumferential direction of the flange, the rotation of the output member becomes smooth, and the rotational accuracy of the input shaft and the rotor of the electric motor fitted and secured to the input shaft is improved.
Advantageous Effects of Invention
[0022] As described so far, since the present invention is configured such that a pair of bearings supporting an input shaft of a speed reduction unit are both attached to an output member of the speed reduction unit, both the bearings are prevented from being subjected to eccentric load. As a result of this, the present invention can achieve the effects of improving the rotational accuracy of the input shaft and the durability of the bearings, and further suppressing the rotation noise of the bearings.
[0023] Moreover, since the suspension joining portion is provided in the housing, there is no need of providing a knuckle on the vehicle body side, thus allowing reduction of the number of parts on the vehicle body side.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 is a cross sectional view of Embodiment 1.
[0025] FIG. 2 is a partially enlarged cross sectional view of Embodiment 1.
[0026] FIG. 3 is an enlarged sectional view taken in X 1 -X 1 line in FIG. 2 .
[0027] FIG. 4 is a perspective view of a spacer shown in FIG. 3 .
[0028] FIG. 5 is a cross sectional view taken in X 2 -X 2 line in FIG. 1 .
[0029] FIG. 6A is a cross sectional view of a variant of a speed reduction unit portion.
[0030] FIG. 6B is a cross sectional view taken in X 3 -X 3 line of FIG. 6A .
[0031] FIG. 7 is a cross sectional view to show a part of Embodiment 2.
[0032] FIG. 8 is a cross sectional view of Embodiment 3.
[0033] FIG. 9 is a side view of Embodiment 3.
[0034] FIG. 10 is a partial cross sectional view of a variant of Embodiment 3.
DESCRIPTION OF EMBODIMENTS
[0035] Hereafter, embodiments of the present invention will be described based on the appended drawings.
Embodiment 1
[0036] A drive device for an electric vehicle relating Embodiment 1 includes, as principal components, an electric motor 11 , a speed reduction unit 12 which is driven by the output power of the electric motor 11 , a hub unit 15 which is rotated by an output member 14 coaxial with an input shaft 13 of the speed reduction unit 12 , and a housing 16 which accommodates the electric motor 11 and the speed reduction unit 12 , as shown in FIG. 1 .
[0037] The above-described housing 16 includes a cylindrical portion 17 and a front end portion 18 in the radial direction, which is provided at the front end of the cylindrical portion (the end portion of an outboard side, or an end portion on the left side of the figure). A central portion of the front end portion 18 is opened, and a rear end portion of an outer member 21 of the hub unit 15 is fitted into an opening hole 19 so that a flange 22 is secured to the front end portion 18 with a bolt 23 .
[0038] A partition base portion 18 a, which is concentric with the opening hole 19 and has a larger diameter than that, is provided inside the front end portion 18 of the housing 16 . A dish-shaped partition member 20 is secured to the partition base portion 18 a with a bolt 20 a. A center hole 25 is provided at the center of the partition member 20 . The center hole 25 faces an outer radial surface of the input shaft 13 with a gap in a radial direction therebetween. A partition 24 is formed of the above-described partition base portion 18 a and the partition member 20 joined and secured thereto. The partition 24 has a function of sectioning the interior of the housing 16 into an accommodation space for the electric motor 11 on the outer radial side, and an accommodation space for the speed reduction unit 12 on the inner radial side.
[0039] A suspension joining portion 27 which projects in the axial direction is provided at two centrosymmetric locations on a rear end edge of the cylindrical portion 17 of the housing 16 . In a conventional automobile, the hub unit 15 is joined to the suspension with a knuckle of the vehicle body lying therebetween; however, in the present Embodiment 1, the suspension on the vehicle body side can be directly joined to the suspension joining portion 27 which is a part of the housing 16 .
[0040] Since the housing 16 will achieve the function of the knuckle, it can be described as a structure in which the knuckle is integrated with the housing 16 . In this case, if the outer member 21 of the hub unit 15 becomes necessary to be replaced, the replacement can be performed simply by detaching the bolt 23 without need of detaching the housing 16 from the suspension.
[0041] In the case shown in the figure, the electric motor 11 is a radial-gap-type brushless DC motor, and is made up of a stator 28 secured to an inner radial surface of the cylindrical portion 17 of the housing 16 , and a rotor 29 disposed on an inner radial surface of the stator 28 with a radial gap. The rotor 29 is fitted and secured to the input shaft 13 by a rotor support member 31 .
[0042] The rotor support member 31 is made up of a support member cylindrical portion 31 a (see FIG. 2 ) fitted to an inner radial portion of the rotor 29 , and a support member disc portion 31 b which extends reward along the partition 24 and which is bent to the inner radial direction of the partition. A boss portion 31 c is provided in an inner radial portion of the support member disc portion 31 b, and the boss portion 31 c is fitted to the input shaft 13 and secured to the input shaft 13 with a key locking portion 35 .
[0043] The above-described boss portion 31 c is inserted into the inner radial side of the center hole 25 of the partition 24 , and an oil seal member 36 is placed between the center hole 25 and the boss portion 31 c (see FIG. 2 ). The accommodation portion of the electric motor 11 and the accommodation portion of the speed reduction unit 12 are partitioned and oil-sealed by the partition 24 and the oil seal member 36 . As a result of this, lubricant oil on the speed reduction unit 12 side is prevented from moving to the electric motor 11 side, and thus the electric motor 11 side is kept dry, thus resolving the malfunction that the lubricant oil hinders the rotation of the rotor 29 .
[0044] The speed reduction unit 12 is of a planetary gear type, and is made up of, as shown in FIG. 2 , the input shaft 13 , the output member 14 , a sun gear 39 which is attached to the outer radial surface of the input shaft with a key locking portion 38 , a ring gear 42 which is disposed along an inner radial surface of a partition cylindrical portion 24 b in the outer periphery of the sun gear 39 , and which is attached with a key locking portion 41 , and pinion gears 43 which are disposed at three locations equally spaced in the circumferential direction between the ring gear 42 and the sun gear 39 . The pinion gear 43 is supported by a pinion pin 45 via a needle roller bearing 44 .
[0045] The output member 14 includes a coupled shaft portion 47 at an end portion of an outboard side thereof. The coupled shaft portion 47 is spline-coupled to an inner member 46 of the hub unit 15 and secured by a nut 50 . A bearing support portion 49 , which is formed to have a one-step larger diameter than that of the coupled shaft portion 47 , is provided on the inner end side of the coupled shaft portion 47 .
[0046] On an inboard side of the output member 14 , a pair of flanges 52 and 53 which oppose each other in the axial direction are provided with a spacing slightly larger than the width of the pinion gear 43 in the axial direction. A bridge 54 for joining the flanges 52 and 53 to each other in the axial direction is provided at three locations of equally spaced positions in the circumferential direction. The flanges 52 and 53 have a function as a carrier in the speed reduction unit 12 of planetary gear type.
[0047] Providing the bridge 54 at equally spaced positions in the circumferential direction allows the output member 14 to be smoothly rotated, and moreover, to improve the rotational accuracy of the rotor 29 of the electric motor 11 through the output member 14 and the input shaft 13 .
[0048] A shaft hole 51 which is coaxial with the coupled shaft portion 47 is provided at the center of an end surface of the flange 53 of the inboard side. This shaft hole 51 has a length reaching the bearing support portion 49 .
[0049] There are provided pinion gear accommodation portions 55 at the three locations, which are sectioned in the circumferential direction by the pair of the flanges 52 and 53 opposing each other in the axial direction, and the bridges 54 at the three locations in the circumferential direction (see FIG. 3 ). The pinion gear 43 is accommodated in each pinion gear accommodation portion 55 , and both end portions of the pinion pin 45 are inserted through the flanges 52 and 53 , respectively, and each secured by a locking screw 56 . It can be said that both the flanges 52 and 53 are coupled and integrated with each other not only by the bridge 54 , but also by the pinion pin 45 .
[0050] Since the flanges 52 and 53 are integrated with each other by the bridge 54 , the support stiffness at both ends of the pinion pin 45 increases.
[0051] A thrust plate 57 is placed between each side surface of each pinion gear 43 and each of the flanges 52 and 53 to ensure smooth rotation of the pinion gear 43 .
[0052] A pair of rolling bearings 58 and 59 for supporting the input shaft 13 are provided on both sides of the sun gear 39 between an inner radial surface of each of the flanges 52 and 53 and the outer radial surface of the input shaft 13 opposing each of the inner radial surfaces of the flanges 52 and 53 . By adopting this configuration, the respective rolling bearings 58 and 59 are supported together by the same output member 14 .
[0053] Further, as shown in FIG. 2 , the positional relationship in the axial direction between each of the rolling bearings 58 and 59 , and a fitting portion between the support member disc portion 31 b and the input shaft 13 is such that the respective rolling bearings 58 and 59 are disposed together on the outboard side, and form a so-called cantilever support structure as the support structure for the input shaft 13 .
[0054] In contrast to this, in the conventional art (Patent Literature 1), while the bearing on the outboard side is disposed on the outboard side with respect to the fitting portion between the support member disc portion and the input shaft, the bearing on the inboard side is attached to the housing, and therefore is located on the inboard side with respect to the above-described fitting portion. Therefore, the support structure of the input shaft forms a so-called both-end support structure. The cantilever support structure is characterized by a simplified structure compared with the both-end support structure.
[0055] The above-described rolling bearing 58 on the outboard side is configured such that its inner ring is engaged with a stepped portion 61 provided in the input shaft 13 , and its outer ring is engaged with a stepped portion 62 provided in an inner radial surface of the shaft hole 51 . The rolling bearing 59 on the inboard side is configured such that its inner ring is engaged with the boss portion 31 c of the rotor support member 31 and the key locking portion 35 , and its outer ring is engaged with a retaining ring 63 .
[0056] The sun gear 39 is placed between the respective inner rings of the respective rolling bearings 58 and 59 , and also a spacer 64 is placed between the outer rings. The spacer 64 prevents both the rolling bearings 58 and 59 from being displaced in a direction to approach to each other.
[0057] The spacer 64 is formed into a cylindrical form as shown in FIGS. 3 and 4 , and is provided, at three locations in the circumferential direction, with window holes 65 which correspond to the shape of the above-described pinion gear accommodation portion 55 . Further, a closure portion 66 between the respective window holes 65 is formed into a shape corresponding to the shape of the bottom plane of the above-described bridge 54 . The spacer 64 is placed between the rolling bearings 58 and 59 on the inner radial surface of the shaft hole 51 in a posture that each window hole 65 corresponds to the pinion gear accommodation portion 55 (see FIG. 3 ), and is configured to be positioned by screwing a securing screw 67 from an outer radial surface of the bridge 54 into a positioning hole 60 (see FIG. 4 ).
[0058] The above-described spacer 64 allows to control the bearing pressurization to be applied to both the rolling bearings 58 and 59 by appropriately setting the axial length thereof, thus providing a simple fixed-position pressurization structure.
[0059] When seen in the radial direction, the speed reduction unit 12 is radially disposed to be accommodated on the inner radial side of the electric motor 11 with respect to the partition 24 , and the size in the axial direction is made compact compared with a case where the unit is disposed in the axial direction.
[0060] Here, additionally describing the partition 24 , the partition cylindrical portion 24 b is placed between the electric motor 11 and the speed reduction unit 12 , which are disposed in the radial direction, and a partition disc portion 24 a is placed between the speed reduction unit 12 and the support member disc portion 31 b. A peripheral edge portion of the center hole 25 faces the outer radial surface of the boss portion 31 c of the rotor support member 31 with a predetermined spacing therebetween. The ring gear 42 of the speed reduction unit 12 is secured to an inner radial surface of the partition base portion 18 a with the key locking portion 41 .
[0061] The oil seal member 36 is placed between the peripheral edge portion of the above-described center hole 25 and the boss portion 31 c. The accommodation space for the electric motor 11 of the housing 16 and the accommodation space for the speed reduction unit 12 are partitioned by the presence of the oil seal member 36 and the partition 24 . Since, as a result of this, the lubricant oil on the speed reduction unit 12 side is prevented from moving to the electric motor 11 side, and thus the electric motor side is kept dry, the lubricant oil is prevented from hindering the rotation of the rotor 29 .
[0062] Although, it is described above that both the flanges 52 and 53 of the output member 14 are coupled and integrated by both the bridge 54 and the pinion pin 45 , it is possible to take a structure in which the flange 53 is configured to be a separate body from the output member 14 and both are coupled and integrated by the pinion pin 45 , as shown in FIGS. 6A and 6B .
[0063] An oil filler port 68 and an oil drainage port 69 for lubricant oil to lubricate the interior of the speed reduction unit 12 are provided in the front end portion of the housing 16 . The lubricant oil is sealed by the above-described oil seal member 36 on the electric motor 11 side, and is sealed by an oil seal member 70 , which is placed between the bearing support portion 49 of the output member 14 and the outer member 21 , on the hub unit 15 side. The oil filler port 68 and the oil drainage port 69 are blocked by a blocking screw 72 .
[0064] Since the electric motor 11 and the speed reduction unit 12 , excepting the rear end portion (the end portion of the inboard side) of the input shaft 13 , fit in the range of the axial length of the cylindrical portion 17 of the housing 16 as shown in FIG. 1 , a rear cover 73 is fitted to the rear end portion of the cylindrical portion 17 via a seal member 60 . A fin 74 for heat dissipation is provided on an outer side surface of the rear cover 73 so that heat of the electric motor 11 is dissipated to the outside.
[0065] A rotation angle sensor 75 is provided between the center hole of the rear cover 73 and the input shaft 13 that passes through the center hole, and that portion is covered by a sensor cover 77 . The rotation angle sensor 75 shown is a resolver, and whose sensor stator 75 a is secured into the center hole of the rear cover 73 , and a sensor rotor 75 b is attached to the input shaft 13 .
[0066] A lead wire 83 of the sensor stator 75 a is connected to a connector insertion portion 78 provided outside the sensor cover 77 . As the rotation angle sensor 75 , a Hall element can be used besides the above-described resolver.
[0067] A rotational angle of the input shaft 13 detected by the rotation angle sensor 75 is inputted to a control circuit, which is omitted from showing, via the above-described signal wire cable to be used for the rotational control of the electric motor 11 .
[0068] A power supply terminal box 76 for providing power supply to the stator 28 of the electric motor 11 is provided at a position decentered toward an outer peripheral edge of the above-described rear cover 73 , and at a position 90 degrees different from the above-described suspension joining portion 27 (see FIG. 5 ).
[0069] The power supply terminal box 76 is formed into a cylindrical shape that passes through the rear cover 73 , and is provided with a working hole 80 in an outer peripheral portion of the box. The working hole 80 is usually blocked by a cover 81 . A power supply terminal 82 is provided inside the box at a position opposing the working hole 80 . A lead wire 83 connected to the winding of the stator 28 is connected to the power supply terminal 82 , and also a connection terminal of a power supply cable 84 is connected to the same power supply terminal 82 . These are secured by fastening screws 85 . A cable hole 84 a is provided at a rear end of the power supply terminal box 76 and the power supply cable 84 is inserted therethrough.
[0070] The hub unit 15 is made up of, as shown in FIG. 1 , the above-described inner member 46 which is integrated with a hub 86 , a pair of inner rings 87 that are fitted to an outer radial surface of the inner member 46 , the outer member 21 having the flange 22 , an outer ring 88 fitted to an inner radial surface of the outer member 21 and having multiple rows of tracks, and multiple rows of balls 89 to be placed between the inner ring 87 and the outer ring 88 . The vehicle wheel is attached to the hub 86 with hub bolts 90 .
[0071] The coupled shaft portion 47 of the output member 14 is spline-coupled to an inner radial surface of the inner member 46 , and a tip end portion of the coupled shaft portion 47 projecting to the outside from the inner member 46 is secured by the nut 50 as described above. In place of the securing means using the nut 50 , securing means such as press cut joint, diameter expansion caulking, and swing caulking may be adopted.
[0072] Although the above-described hub unit 15 is of a form of so-called first generation, those of a form of the second generation or third generation may be used.
[0073] The driving device for an electric vehicle of Embodiment 1 is configured as described above, and next, the operation thereof will be described.
[0074] When the electric motor 11 is driven by an accelerator at the driving seat being activated, the input shaft 13 is rotated integrally with the rotation of the rotor 29 , and a motor output is inputted to the speed reduction unit 12 . In the speed reduction unit 12 , when the sun gear 39 rotates integrally with the input shaft 13 , the pinion gears 43 revolve around the sun gear 39 while rotating on their own axes. Each of the pinion pins 45 performs speed-reduced rotation at its revolving speed, and thereby rotates the output member 14 at a speed-reduced output shown by the above-described speed reduction ratio.
[0075] The inner member 46 of the hub unit 15 is rotated integrally with the coupled shaft portion 47 of the output member 14 , thereby driving the wheel attached to the hub 86 .
[0076] The above-described input shaft 13 rotates by being supported respectively by the rolling bearing 58 on the outboard side and the rolling bearing 59 on the inboard side at both sides of the pinion gear 43 . Since these rolling bearings 58 and 59 are both attached to the respective flanges 52 and 53 (respective flanges 52 and 53 which are integrated via the pinion pin 45 in the case of FIGS. 6A and 6B ) which are each integrated with the output member 14 , vibration and impact in the radial direction which are transmitted from the wheel to the output member 14 through the hub unit 15 is imposed onto both the rolling bearings 58 and 59 at the same time and in the same manner.
[0077] Since, as a result of that, both the rolling bearings 58 and 59 can be prevented from being subjected to eccentric load, it is possible to improve the rotational accuracy and durability, and suppress the rotation noise.
[0078] Since the pinion pin 45 of the pinion gear 43 is supported at both end portions thereof by the respective flanges 52 and 53 , the support stiffness increases compared with a conventional case where it is cantilevered.
[0079] The above-described rolling bearings 58 and 59 are disposed on the outboard side with respect to the fitting portion between the rotor support member 31 of the rotor 29 and the input shaft 13 , that is, the key locking portion 35 , so that the support structure becomes simple and easy to be assembled compared with a conventional case where the bearings are disposed on both sides thereof.
[0080] Further, since the lubricant oil in the speed reduction unit 12 is sealed on the electric motor 11 side by the oil seal member 36 , and sealed on the hub unit 15 side by the oil seal member 70 , leakage on the electric motor 11 side and the hub unit side is prevented. As a result of that, on the electric motor 11 side, rotation of the rotor 29 is not hindered, and on the hub unit 15 side, leakage of the lubricant oil to the outside through the hub unit 15 is prevented.
[0081] The heat generated in association with the driving of the electric motor 11 is effectively dissipated by the fin 74 of the rear cover 73 .
[0082] The rotational angle of the input shaft 13 , which is necessary for the rotational control of the electric motor 11 , is detected by the rotation angle sensor 75 and inputted to the control apparatus.
Embodiment 2
[0083] Embodiment 2 shown in FIG. 7 differs in the configuration of the hub unit 15 compared with the above-described Embodiment 1. That is, the flange 22 of the outer member 21 of the hub unit 15 in this case is formed to have a larger diameter than that of the flange 22 (see FIG. 1 ) of the above-described Embodiment 1.
[0084] A flange cylindrical portion 32 projecting in the axial direction is provided in the inner side surface of the flange 22 with a larger diameter. The flange cylindrical portion 32 extends over an outer radial surface of the flange 53 on the outboard side of the output member 14 . The flange cylindrical portion 32 is fitted to an inner radial surface of the opening hole 19 of the front end portion 18 of the housing 16 .
[0085] Since, compared with the case of Embodiment 1, the opening hole 19 is formed to have a large inner diameter, it is easy to fabricate the partition 24 which is integrated with the front end portion 18 , in the case of this Embodiment 2. For this reason, in the case of Embodiment 2, the partition member 20 (see FIG. 1 ) which is a separate member is not used.
[0086] A ball of a hub bearing 89 a on the outboard side is placed between a track groove formed in the outer radial surface of the inner member 46 , and a track groove formed in the inner radial surface of the outer member 21 . Moreover, the ball of the hub bearing 89 b on the inboard side is placed between a track surface formed in the outer radial surface of the flange 52 and a track groove formed in an inner radial surface of the flange cylindrical portion 32 .
[0087] Letting the radii from “the center” of the ball center of the hub bearing 89 a on the outboard side, the center of the pinion shaft 45 , and the ball center of the hub bearing 89 b on the inboard side be r 1 , r 2 , and r 3 , respectively, these sizes have a relationship as r 1 <r 3 , and r 2 <r 3 . Other configurations are the same as those of the case of Embodiment 1.
[0088] As describe above, setting the ball PCD (pitch circle diameter) of the hub bearing 89 b on the inboard side to be larger than the ball PCD of the hub bearing 89 a on the outboard side results in increasing in the bearing stiffness of the hub unit 15 .
[0089] It is noted that the hub unit 15 in this case can be said to be a variant form of the so-called third generation.
[0090] Although, in the illustrated case, each of the balls of the hub bearings 89 a and 89 b is configured to be in direct contact with the track groove, it is also possible to configure such that a bearing in which the track groove is provided in each of its inner ring and outer rings is used, and these track rings are fitted to the aforementioned opposite members.
Embodiment 3
[0091] Embodiment 3 shown in FIGS. 8 to 10 differs from Embodiment 1 in the configurations of the hub unit 15 , the rotation angle sensor 75 , the power supply terminal box 76 , and the connector insertion portion 78 .
[0092] That is, the hub unit 15 in this case is formed such that the flange 22 of the outer member 21 has a larger diameter than in the case of Embodiment 1. For this reason, there is no need of adopting a supplementary housing 16 b as in Embodiment 1, and the single housing 16 which has a similar structure to that of a main housing 16 a is used. The flange 22 with a larger diameter is secured to the housing 16 with the bolt 23 .
[0093] The ball 89 a on the outboard side constituting the hub bearing is placed between the track groove provided in the outer radial surface of the inner member 46 and the track groove provided in the inner radial surface of the outer member 21 . Further, the ball 89 b on the inboard side is placed between the track groove provided in the outer radial surface of the output member 14 and the track groove provided in the inner radial surface of the outer member 21 . It can be said to be a variant type of the so-called third-generation.
[0094] The rotation angle sensor 75 is provided between opposite surfaces in the axial direction of the support member disc portion 31 b of the rotor support member 31 , and the partition disc portion 24 a. A sensor rotor 91 a is made up of a magnet which is attached to the support member disc portion 31 b with a vis 92 . Moreover, a sensor stator 91 b is made up of a Hall element attached to the opposite surface of the partition disc portion 24 a with a vis 93 . Both oppose each other via an axial gap.
[0095] As shown in FIG. 10 , the cross sectional shape of the sensor rotor 91 b may be formed into a reverse L-shape, and a radial gap may be formed between the horizontal portion of the sensor rotor 91 b and the sensor stator 91 a.
[0096] The power supply terminal box 76 and the connector insertion portion 78 are both provided in the housing 16 (see FIG. 9 ). The power supply terminal box 76 is configured such that an accommodation recessed portion 94 is provided within the range of the wall thickness of a rear end surface of the housing 16 , and the power supply terminal 82 is provided inside the accommodation recessed portion 94 . A communication hole 95 in communication with the interior of the housing 16 is provided in a deep part of the accommodation recessed portion 94 . The opening surface of the accommodation recessed portion 94 is blocked by a cover member 96 . The cover member 96 is provided with a cable hole 97 for passing the power supply cable 84 .
[0097] Further, the working hole 80 is provided in the wall surface of the housing 16 . This working hole 80 is usually blocked by the cover 81 . The lead wire 83 on the electric motor 11 side is connected to the power supply terminal 82 through the communication hole 95 , and the power supply cable 84 is drawn in through the cable hole 97 so that its connection terminal is connected to the power supply terminal 82 . Both are coupled to the power supply terminal 82 with a fastening screw 85 .
[0098] The connector insertion portion 78 is provided in the rear end surface of the housing 16 side-by-side with the power supply terminal box 76 , as shown in FIG. 9 . The connector insertion portion 78 is configured such that a recessed portion 99 is provided in the rear end surface of the housing 16 , and a lead wire hole 100 which brings a deep part of the recessed portion 99 and the interior of the housing 16 into communication is provided (see FIG. 8 ). A lead wire 101 of the rotation angle sensor 75 is connected to the interior of the recessed portion 99 through the lead wire hole 100 . The connector (not shown) of the signal cable is inserted into the connector insertion portion 78 .
[0099] As described above, the configuration in which both the power supply terminal box 76 and the connector insertion portion 78 are provided in the housing 16 can simplify the configuration of the rear cover 73 so that it can be made up of a thin metal plate, a plastic plate, and the like.
REFERENCE SIGNS LIST
[0000]
11 Electric motor
12 Speed reduction unit
13 Input shaft
14 Output member
15 Hub unit
16 Housing
17 Cylindrical portion
18 Front end portion
18 a Partition base portion
19 Opening hole
20 Partition member
20 a Bolt
21 Outer member
22 Flange
23 Bolt
24 Partition
24 a Partition disc portion
24 b Partition cylindrical portion
25 Center hole
26 Fin
27 Suspension joining portion
28 Stator
29 Rotor
31 Rotor support member
31 a Support member cylindrical portion
31 b Support member disc portion
31 c Boss portion
32 Flange cylindrical portion
35 Key locking portion
36 Oil seal member
38 Key locking portion
39 Sun gear
41 Key locking portion
42 Ring gear
43 Pinion gear
44 Needle roller bearing
45 Pinion pin
46 Inner member
47 Coupled shaft portion
48 Rolling bearing
49 Bearing support portion
50 Nut
51 Shaft hole
52 , 53 Flange
54 Bridge
55 Pinion gear accommodation portion
56 Locking screw
57 Thrust plate
58 , 59 Rolling bearing
60 Positioning hole
61 , 62 Stepped portion
63 Retaining ring
64 Spacer
65 Window hole
66 Closure portion
67 Securing screw
68 Oil filler port
69 Oil drainage port
79 Oil seal member
71 Groove
72 Blocking screw
73 Rear cover
74 Fin
75 Rotation angle sensor
75 a Sensor stator
75 b Sensor rotor
76 Power supply terminal box
76 a Power supply terminal
77 Sensor cover
78 Connector insertion portion
79 Insertion hole
80 Working hole
81 Cover
82 Power supply terminal
83 Lead wire
84 Power supply cable
84 a Cable hole
85 Fastening screw
86 Hub
87 Inner ring
88 Outer ring
89 Ball
89 a, 89 b Hub bearing
90 Hub bolt
91 a Sensor rotor
91 b Sensor stator
92 , 93 Vis
94 Accommodation recessed portion
95 Communication hole
96 Cover member
97 Cable hole
99 Recessed portion
100 Lead wire hole
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The present structure does not require a knuckle on the vehicle body side, improves rotational accuracy of an input shaft of a speed reduction unit, increases durability of bearings, and suppresses rotation noise of the bearings by improving the supporting structure of the input shaft of the speed reduction unit. In a drive device for an electric vehicle comprising: a speed reduction unit including an input shaft driven by an electric motor; a hub unit rotationally driven by an output member of the speed reduction unit; and a housing accommodating the electric motor and the speed reduction unit, wherein the input shaft of the speed reduction unit is supported by bearings provided at two locations in the axial direction, the drive device is configured such that the bearings provided at the two locations are both supported by the output member, and the housing is provided with a suspension joining portion.
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[0001] This application is a division of application Ser. No. 08/865,419 filed May 28, 1997.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a water-based mineral stain for wood and other substrates. More specifically, the invention relates to a process in which a metal salt and an oxygen source react with the substrate to provide a stable color or other desired effect such as preserving substrate.
[0003] Many commercial stains readily available on the market are oil or solvent-based and/or contain hazardous chemicals subject to increasing environmental regulation and health concerns. There is a growing need for water-based colorants and finishes that contain no hazardous chemicals. Federal and state initiatives are leading to bans on stains using volatile organic compounds (e.g. petroleum, mineral spirits, toluene, or benzene).
[0004] Most water-based products for coloring and finishing wood and other materials are primarily based upon a pigment or dye suspended in a binder such as acrylic resin, which is spread onto the wood surface and held in place by the binder. Such products, although less toxic, exacerbate a problem of all conventional stains, namely that while coloring a wood such as pine they sink in more deeply into the soft pulp and are repelled by the harder wood around the annual growth rings formed during the dormant period in a tree's growing season. For example, stains such as Minwax™ can color pine to a maple-like general color, but in doing so emphasize the distinctive grain-markings characteristic of pine. Such products tend to produce marginal results and an un-even staining pattern. There would be great advantages for a stain capable of coloring both hard and soft woods evenly allowing for a maple-like overall color with a much more subtle grain pattern, thereby allowing a soft wood to mimic the appearance of a hard wood more effectively. Also, water-based stains tend to raise wood grain, requiring additional sanding.
[0005] There is a need for a coloring process having the environmental benefit of allowing rapidly growing, sustainably harvestable woods such as pine and other fast-growing and therefore “renewable” wood resources to give the visual appearance of endangered hardwoods such as mahogany, ebony, redwood, and other species that are increasingly rare and expensive.
[0006] The construction, furniture, and woodworking industries need new improved water-based stains effective for soft woods. Likewise, there is a need for environmentally beneficial coloring processes for wood products such as paper and cardboard, for fabrics for clothing and upholstery, and for manufactured polymer products.
[0007] Conventional stains take a relatively long time to dry and can only be applied in temperatures at or above 55 degrees F. There is a need for a stain that can be applied outside this range, for example, for exterior woodwork in a colder climate.
[0008] Conventional stains are made up of a binder and a pigment or dye. Many of these coloring agents are “fugitive,” fading over time, especially in exterior settings. A stable coloring agent that is permanent and does not fade over time and even becomes richer and slightly darker would be an improvement over conventional stains.
[0009] Conventional stains can be used on dry, cured wood only. There is a need for stains that can be applied to damp or “green” un-cured wood. Conventional stains coat the surface of aromatic woods such as cedar, preventing the natural aroma from being released by the wood. There are advantages to stains that leave a wood fully aromatic. Oil-based conventional stains can be difficult to over-coat with water-based acrylic finishes. A stain that can be over-coated with any type of oil or water-based finish would have pronounced advantages.
[0010] Stains used to simulate wood aging, such as Cabot Stains Bleaching Oil™ can only be used for exterior use and the appearance of aging of the wood takes many months from application. An aging treatment that can be used indoors and occurs immediately has clear advantages. Other aging processes require the use of harsh acids, bleaches and other toxic chemicals and require complex manual wood-distressing techniques such as multiple layering of different stains to mimic grain patterns of aged wood. Preferable would be an aging treatment that is non-toxic and can be applied easily by a layman.
[0011] Some coloring processes have been developed to compensate for the unattractive green color of CCA (copper-chromium-arsenic) pressure-treated preserved lumber, such as Leach, U.S. Pat. Nos. 4,752,297 and 4,313,976. These processes rely on organic acids and other organic compounds. They are concerned primarily with preservation of wood, are able to produce only a limited color palate, and are not of general applicability.
[0012] A process of using an aqueous solution of an alkaline earth metal base to treat wood is described in Gaines et al. U.S. Pat. No. 4,757,154. This method requires immersing wood at high temperature and pressure and sanding to remove an unattractive deposit, so it is not a viable method for staining wood. Some woodworkers soak wood in a solution of iron-rich fertilizer to produce a dusty gray tone. The coloring is unstable, uneven, fades over time, leaches out if exposed to moisture, and if overcoated creates an unattractive residue, so it is not in regular use.
SUMMARY OF THE INVENTION
[0013] According to the invention, a metal salt and an oxygen source are applied to penetrate or impregnate a suitable substrate sequentially in effective amounts so as to react in contact with the substrate and produce a mineral compound fixed within the surface of the substrate. The inventive combination of a mutually compatible metal salt, oxygen source, and substrate brings about an in situ reaction, and modifies the substrate to bring about a lasting desired effect. The mineral compound that is produced according to the invention is linked to the substrate, is stable and long-lasting or permanent, and is immobilized or insolubilized in the substrate. The mineral compound is bound or contained within and on the surface of the substrate, so it may be said to be ingrained in the fibers or matrix of the substrate, or incorporated or embedded within the substrate. The desired effect is preferably a color. A wide variety of metal salts may be used depending on the desired effect. The oxygen source is preferably a peroxide, and the substrate is preferably a cellulose product such as wood, cotton, or paper; leather; or masonry. The invention contemplates methods of treating substrates, treatment kits, and treated products.
[0014] This invention satisfies a long felt need for a water-based, non-toxic stain for woods and other substrates that provides a permanent even coloring effect. The invention is in the crowded and mature art of colorants, preservatives, and finishes for wood and other substrates, yet it has not previously been discovered or used.
[0015] The wood-stain industry has been searching for ways to reduce toxic chemical use, to more effectively stain woods such as pine that are difficult to work with and relatively inexpensive, and to simulate the appearance of aging. The demand is such that any feasible process tends to be put into use.
[0016] This invention succeeds where previous efforts have failed. It avoids the need for volatile organic solvents and toxic compounds, heat, or pressure—elements employed in the prior art—without loss of ability, and indeed with improved results. It can be applied to a wide variety of woods and other substrates with excellent, permanent results. It works quickly in environments and temperatures inappropriate for conventional treatments, and is simple enough to be used by an amateur.
[0017] This invention solves previously unrecognized problems, including how to react a substrate with a soluble mineral salt and an oxygen source to color the substrate; how to satisfy consumer aesthetics limiting the substitutability of sustainable woods for endangered species; and how to use a single staining system for a wide variety of wood and non-wood substrates. This invention also solves the problem of evenly staining and rapidly aging soft woods and green woods and related materials, which was generally thought to be insoluble. The advantages provided by the invention could not previously have been appreciated, such as its adaptability to a variety of overcoat finishes, the ability to stain without appreciably raising wood grain, and its retention of the aromatic quality of the substrate.
[0018] This invention differs from the prior art in modifications which were not previously known or suggested, such as using mineral salts and peroxide solutions to produce surprising coloring effects. Indeed, this invention is contrary to the teachings of the prior art, which favors one step treatments using colored pigments, rather than two step processes whereby the color is developed and stabilized during the process.
[0019] The inventive approach to the coloring and preserving of cellulose and other materials is a process whereby a water-soluble mineral salt is saturated into the substrate material and subsequently oxidized and somehow linked or bonded to that material. This process has no precedent in the marketplace and provides important advantages in both the commercial and consumer markets. In a preferred embodiment, the inventive stains are completely water-based. The process does not require a binder of any kind, petroleum products, organic solvents, acrylic resins, dyes, or other expensive or toxic materials. The component materials have low-impact on both the environment and human heath. The unique characteristics of the product, its permanence even in exterior applications, its ability to evenly stain extremely soft woods and penetrate extremely hard woods, its simulated aging of wood, and the richness of the colors achieved will appeal even to those completely un-concerned about its environmental and health advantages.
[0020] According to the invention, a method for coloring a substrate comprises:
[0021] (a) applying a preparation of a metal salt to the substrate, and
[0022] (b) separately applying a preparation of an oxygen source to the substrate, such that the metal salt and the oxygen source penetrate the substrate and react in contact with the substrate to produce a stable, water-insoluble stain or other fixed physical characteristic in the substrate.
[0023] Step (a) may be performed before or after step (b), and there may be a step of drying the substrate between the two steps. Preferably the preparations are aqueous solutions and are applied between the freezing point and boiling point of the solutions as determined under the particular process conditions selected for the method. The method may further comprise applying a sealing coat over the substrate surface.
[0024] In a preferred embodiment, the substrate is a sustainably harvested wood, the stain is relatively uniform, the metal salt is of low toxicity and not considered hazardous, the preparations of metal salt and oxygen source are water-based solutions, and the oxygen source leaves essentially no residue. Preferably, the metal salt preparation and the oxygen source preparation are aqueous solutions.
[0025] The metal salt may be any appropriate mineral salt and is preferably a salt of iron, silver, zinc, cerium, copper, magnesium, molybdenum, nickel, tin, chromium, aluminum, and titanium, or a salt of antimony, beryllium, bismuth, cadmium, cobalt, gold, iridium, lead, manganese, mercury, niobium, osmium, platinum, plutonium, potassium, rhodium, selenium, silicon, sodium, tantalum, thorium, tungsten, uranium, vanadium, or a combination. The principal purpose of staining with the mineral may be to impart a desirable color to the substrate, to preserve the substrate, or both.
[0026] The metal salt is preferably selected from sulfates, chlorides, perchlorates, permanganates, thiosulfates, acetates, nitrates, as well as oxides that are subject to reduction to release a metal ion capable of reacting with the oxygen source in the presence of the substrate to produce a color. Other salts that may be suitable include halides, phosphates, carbonates, nitrates, oxalates, silicates, tartrates, formates, chromates, organic salts, and the like, so long as the metal ion or compound is sufficiently soluble to penetrate the substrate and is able to react with the oxygen source preparation to produce the desired color or other desired fixed quality in the substrate.
[0027] Preferred metal salts are silver sulfate, iron (II) chloride, zinc perchlorate, cerium (III) perchlorate, iron (II) perchlorate, iron (II) sulfate, silver perchlorate, copper acetate, magnesium nitrate, and cerium nitrate. Other preferred metal salts are molybdenum (VI) oxide, zinc sulfate, copper (II) chloride, nickel perchlorate, nickel sulfate, copper (II) perchlorate, tin (II) sulfate, tin (I) chloride, chromium (III) sulfate, aluminum sulfate, cerium (III) perchlorate, zinc peroxide, titanium hydride, chromium (III) perchlorate, zinc powder in combination with titanium salts, manganese (II) chloride, aluminum chloride, titanium (IV) chloride, silver chloride, and titanium (H) sulfate.
[0028] Preferably the oxygen source is a peroxide. It may be hydrogen peroxide, sodium peroxide, zinc peroxide, barium peroxide, calcium peroxide, or lithium peroxide. The oxygen source may include a hydroxide such as sodium hydroxide. The oxygen source is capable of penetrating the substrate and reacting with the metal salt to impart a stable color or other physical characteristic to the substrate.
[0029] The substrate is preferably a building material or textile and is preferably a cellulosic material such as a soft wood, hard wood, bamboo, rattan, or other cellulose product, such as cotton, paper, cardboard, or the like. The substrate may be previously coated, such as a latex painted surface. The substrate may be leather, fabric, or porous plastic; or it may be a masonry material such as ceramic, plaster, cement, concrete, stone, brick, or a combination. Preferably the effect achieved in the substrate is a color, typically an earth tone. The substrate is one which can be penetrated and contacted sequentially with the metal salt preparation and the oxygen source preparation so as to produce the desired color or other effect bound stably within the substrate. Preferably the substrate is wood or is a wood-like product, meaning a hard fibrous, cellulose-based product from trees, bamboo, reeds or other agricultural sources, including fiber board, plywood, and veneer.
[0030] The metal salt preparation and/or oxygen source preparation may further comprise a compatible additive selected from the group consisting of thickener, alcohol, emulsifier, coloring agent, pigment, dye, bleach, sealer, finishing agent, tint, acrylic finish, latex finish, polyurethane, alcohol, gelling agent, tabletting agent, surfactant, buffer, citric acid, tannic acid, acetic acid, other acid, base, color, salt, stabilizer, antimicrobial, antifungal, insecticide, insect repellant, ultraviolet protectant, and fire retardant. Other additives now known or hereafter available to a person of skill in the art may be employed so long as they do not interfere with the operation of the components of the invention and have suitable shelf life and other characteristics.
[0031] The invention contemplates a colored or otherwise altered substrate produced by the method of the invention. The colored or altered substrate, at its surface or within, has a stable manufactured composition that imparts color or other desirable characteristics, the composition comprising the products of a chemical reaction in contact with the substrate, between a metal salt, and an oxygen source.
[0032] The invention further contemplates a kit for treating a substrate, comprising (a) a metal salt preparation, and (b) an oxygen source preparation, the preparations being adapted to penetrate the substrate when applied, and both preparations, when applied sequentially in effective amounts, being adapted to react with each other to produce a compound fixed on or in the substrate that is stable, and water-insoluble and imparts a color or other desirable characteristic.
[0033] The metal salt preparation is preferably an aqueous solution comprising between about 0.001% and about 20% (w/v) more preferably about 0.025% to about 8% metal salt. The oxygen source preparation is preferably an aqueous solution comprising between about 0.1% and about 50% (w/v) peroxide, more preferably between about 0.3% and about 15%. The concentration of either component may be the point of saturation of a solution or a higher concentration of an appropriate suspension.
[0034] Further details, objectives, and advantages will become apparent from a consideration of the following description.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] In describing preferred embodiments of the present invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For the sake of simplicity, this description principally addresses application to wood products. In most cases, however, processes and compositions discussed are also applicable to a wide variety of non-wood products.
[0036] The inventive process is a two-step process preferably involving a non-toxic, water-based mineral solution and a low toxicity water-based oxidizing solution applied sequentially to unfinished wood products. The process may be adapted for the coloring and finishing of wood-like products such as bamboo or rattan, paper, recycled cellulose products, cotton and other cloths, leather, certain porous plastics, tile, cement, and other masonry, and other substrate substances.
[0037] The user first brushes, sprays, or otherwise applies a water-based solution “A” onto a wood or other product, lets the product dry for about 5-30 minutes, depending on temperature and humidity, then applies a second water-based solution “B”. Color change begins immediately and when the B solution dries, in another approximately 5-30 minutes, the product is permanently stained. The solutions may also be applied by soaking the substrate in the solution, at standard temperature and pressure or at either extreme or combinations as with typical pressure treatments for lumber to ensure thorough penetration of thicker substrates.
[0038] The inventive process can simulate the look of other, generally more expensive woods (i.e. making pine look like maple, alder look like walnut, or bamboo plywood look like oak). In particular, the coloring process can provide stains that simulate increasingly endangered woods such as mahogany, ebony, and redwood.
[0039] In another application, the process can be used to give new wood an aged appearance for aesthetic reasons, or to allow the unobtrusive introduction of new wood into antique furniture, architectural antiques, fences or shingles that are in need of refurbishment. In such applications, it may be advantageous to distress the surface with rough sanding, sand blasting, chiselling, saw marks, and so on, to allow the minerals to soak in and provide irregular staining. In other applications, it is preferable to maximize the uniformity of the staining, although the stain tends to be somewhat darker around knots and ring areas even with a smooth surface. Nonetheless, staining according to the invention may be uniform, in the sense that it is more even than conventional water-based stains.
[0040] The A solutions contain a variety of mineral salts (such as a variant of the iron-rich compounds found in nutritional supplements) and other natural compounds that soak into the wood surface readily. The B solutions contain an oxidizing agent, such as dilute peroxides similar to the hydrogen peroxide found in many medicine cabinets. Preferred B solutions are somewhat more concentrated.
[0041] Although the invention is not intended to be limited to the mechanism of action, it is believed that the oxygen source causes an oxidation reaction, bonding the minerals in solution A to or among the cellulose fibers in the wood, or other matrix material of a substrate, a process referred to here as “crosslinking.” The chemical nature of the crosslinking reaction is suggested by the fact that a color change results from the combination of solution A, solution B, and the substrate. The resulting color, unlike the clear solutions and their components, is not water-soluble. Also, typically if solutions A and B are mixed without first applying them to the substrate, they throw an unattractive gray-black or gray-brown sediment which is not useful for staining according to the invention. At high strengths and with peroxides, such a reaction is accompanied by bubbling as oxygen is released from the peroxide.
[0042] The process involves saturating the fibers of a wood or other product matrix with a solution of minerals in a water-soluble form and then oxidizing said minerals in the fibers or matrix to change the color, texture, and general appearance of the wood or other properties. It is believed that the coloring process of the invention renders mineral salts into a stable, insoluble form, perhaps an oxide, coordination compound, or other water-insoluble compound or complex, referred to here as a cross linked compound.
[0043] The metal salt formulation soaks into the substrate, impregnating it with mineral ions, which are then converted by the oxygen source into an insoluble coloring compound. Thus, a metal oxide may serve as a metal salt according to the invention, and is contemplated within that definition, if it is solubilized with an acid, applied so as to penetrate into a substrate, and then reacted with an appropriate oxygen source to generate the desired color or other effect. With soluble oxides such as molybdenum IV oxide, the metal oxide may be soaked into the substrate directly, and then reacted to produce a color. Also, solution A may include a combination of a salt of one metal such as titanium chlorate and an elemental metal, such as zinc powder, such that the elemental metal is oxidized by the salt to produce a metal salt which then reacts according to the invention.
[0044] The coloring agent according to the invention may associate physically or chemically with the substrate, via absorption, mechanical admixture, entrapment, polar attraction, or covalent bonding. With cellulosic and leather products, it is assumed that the reaction involves the cellulose or collagen matrix of the substrate article, although it would not affect the scope of the invention if the colored compound remains physically trapped in the matrix of such substrates, without reacting chemically with them. With masonry, the substrate may or may not react with the metal salt and oxygen source, so long as the colored compound is fixed insolubly within the substrate. The scope of the invention is not intended to be limited to any of these supposed mechanisms of action, however.
[0045] The invention also encompasses methods and compositions for imparting other desired stable physical effects to a substrate, where color may be a secondary factor. For example, with certain combinations of metal salts and oxygen sources, the substrate may have an improved texture, conductivity, photosensitivity, anti-fungal, antimicrobial, insect repellant, or fire retardant quality, as a result of treatment according to the invention. Thus the scope of the intention may encompass a method for imparting a desirable stable physical change by sequentially applying preparations A and B to the substrate and allowing them to react so as to fix or bond the reaction product to or within the substrate.
[0046] In some cases, the B solution is applied before the A solution in order to obtain a different effect. Different mineral solutions and different oxidizing agents create markedly different effects on wood, and these finishes can be customized for specific application to a wide variety of materials.
[0047] The invention relates to compositions and kits comprising the various A and B solutions prepared by combining water soluble or other mineral salts, oxidizing agents, and other substances into an aqueous solution.
[0048] The product has a variety of commercial applications including: wood stain, as an alternative to petroleum, acrylic, and latex wood finishes; a wood aging system, to make new wood take on the appearance of old wood; stain for wood-like products, to color and preserve wood-like products such as bamboo; cloth stain, to color cloth, hemp, flax, textiles, leather, and other similar products; wood or other substrate preservation through anti-microbial or anti-fungicidal effects; and masonry stain: to color tile, cement, concrete, brick, stone, and other similar products. The invention can be used both indoors and outdoors, for wood and non-wood products. As can be appreciated, the metal salt can be selected to provide desirable preservative, antifungal, and/or insecticidal properties in addition to a color effect, or can be combined with known preservative treatments. In some applications, the color may be secondary to the ability of the oxygen source to bind or link the metal ion into the substrate according to the two step process of the invention.
[0049] A kit according to the invention can be distributed in two containers such as plastic bottles, one for the A solution and one for the B solution. Bottles A and B can preferably contain a concentrated solution of key mineral salts or oxidizing agents dissolved in water, which the end-user will dilute in a gallon or other volume of water. Alternatively, the product may be distributed in powder or tablet form, requiring the end-user to dilute fully with water. The product can be distributed in fully diluted liquid form, ready to use, which increases shipping costs but reduces variability due to the type of water used and dilution techniques. These decisions can readily be made by a person of ordinary skill depending on acceptance of the various techniques among consumers (such as professional or amateur markets) and the relative difficulty of maintaining certain chemicals' shelf lives in aqueous versus dry conditions. Preferred formulas make use of only non-toxic substances such as iron and silver sulfates and avoid toxic heavy metals such as chromium, cobalt, and lead, which minimize regulatory oversight, and shipping, labelling, and disposal requirements.
[0050] Preferred applications involve water-soluble solutions of minerals of low toxicity, usually in the form of mineral salts such as iron chloride in the A solution, and sodium peroxide or hydrogen peroxide as the oxygen source in the B solution. More toxic metals may also be used for an appropriate result, although they require additional precautions in handling and disposal. Other oxygen sources may be used, and the invention may be carried out in preparations other than water or aqueous solutions. For example, a gel, paste, emulsion, or other thick preparation may be used for either or both components, so long as such a formulation is able to deliver the metal salt and oxygen source into the substrate in a reactive form. Typically, such a thick preparation would be an aqueous solution, although an emulsion with an oil or a suspension may be appropriate in certain applications.
[0051] In a preferred embodiment, to form the various preparations of Solution A, a measured weight of the mineral or minerals is mixed in a volume of purified water. To form the iterations of Solution B, liquid hydrogen peroxide or powdered sodium peroxide are mixed in a volume of water. Alternatively, sodium hydroxide is added to a hydrogen peroxide solution and may be neutralized or buffered if desired. Certain other compounds may serve as an oxygen source according to the invention, such as citric acid on other organic and inorganic acids, provided that they react with an appropriate metal salt according to the invention in contact with the substrate to produce the desired effect.
[0052] The first step in applying the mineral stain is to apply a sufficient amount of Solution A onto the wood or other substrate so that it penetrates, using a brush, pad, roller, spraying device or other suitable method. The solution is generally clear, translucent or slightly cloudy, and alters the color of wood much the same way the application of water would. Some of the A solutions are orange or pink, some milky, some gray. When applied, however, in thin coatings, there is no appreciable color until the oxygen source is applied. Optionally colorants, thickeners, surfactants, and other additives may modify the appearance of the A solution. When the Solution A dries, in 5-30 minutes depending on temperature and humidity etc., the wood looks much as it did before anything was applied to it. A slight graying may be apparent.
[0053] The next step is to apply Solution B to the wood or substrate in much the same manner as Solution A. With a strong Solution B, the color in the wood changes immediately. With weaker solutions, the color comes on slowly, over five minutes or so. The process is reminiscent of making photographic film prints, or watching an instant photograph develop, or making invisible ink become visible. Strong iterations of Solution B have a greater tendency to show brush marks, which can be a negative or positive, depending on the effect desired. The final depth of color in the stained wood is more dependent on the concentration of minerals in Solution A.
[0054] It is possible, in addition to mixing two or more mineral salts in an A solution or two peroxides in the B, to apply first one and then another A, or first a hydrogen peroxide-based and then a sodium peroxide-based B solution. Thus two basic steps of the process might, for certain effects, such as highlighting raised areas with a different color, etc. involve more than two steps.
[0055] The color and tone of the varying wood samples discussed below are described in words but the visual impression of two different samples of wood treated with two different formulas might both be described as “gray brown” though they actually create quite different nuances of visual impression. The colors produced according to the invention are generally earth tones, by which is meant the palate relating to brown, including gray, orange, yellow, red, green and blue variants, ranging from light to virtually black. Opalescent or iridescent effects may be achieved. Brighter coloring effects may also be achieved, as with aluminum oxides. Gray is a preferred effect for simulated aging. The effects may be modified by distressing the surface of the wood to simulate an aged appearance, or by adding pigments and other coloring agents.
[0056] The following mineral salts and oxides have been used according to the invention to stain wood: barium sulfate, calcium sulfate, cerium III nitrate, cerium III perchlorate, copper II nitrate, copper II acetate, copper II carbonate dihydroxide, copper sulfate, iron II sulfate, iron II perchlorate, iron II chloride, sodium thiosulfate, magnesium thiosulfate, potassium thiosulfate, potassium nitrate, potassium permanganate, silver sulfate, silver perchlorate, silver nitrate, titanium III sulfate, and zinc perchlorate.
[0057] Other mineral salts that may be used according to the invention include: aluminum potassium sulfate, molybdenum (VI) oxide, zinc sulfate, copper (II) chloride, nickel perchlorate, nickel sulfate, copper (II) perchlorate, tin (II) sulfate, tin (I) chloride, chromium (III) sulfate, aluminum sulfate, titanium hydride, chromium (III) perchlorate, zinc powder, manganese (II) chloride, aluminum chloride, titanium (IV) chloride, silver chloride, and titanium (II) sulfate.
[0058] Other minerals capable of reacting with an oxygen source in contact with a substrate to color the substrate or provide other effects according to the invention may be selected from salts of elements of columns 2 through 6 of the Periodic Table of the Elements, including the transition elements, Lanthanides, and Actinides. Preferably, the metal is selected from aluminum, antimony, beryllium, bismuth, cadmium, chromium, cobalt, copper, gold, iridium, lead, magnesium, manganese, mercury, molybdenum, nickel, niobium, osmium, platinum, plutonium, potassium, rhodium, selenium, silicon, silver, sodium, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, and zinc.
[0059] As applied to wood and other substrates, the invention may employ any water-soluble mineral salt or oxidized mineral compound soluble in solvents such as acids, alcohols, or other aqueous substances. It may employ any oxidized mineral compounds capable of reacting with an oxygen source and a substrate to form a colored compound linked to the substrate. Such compounds are referred to here collectively for convenience as metal salts, although some of the mineral elements are not metal, and some of the compounds are oxides, not salts.
[0060] The oxygen source may be any oxidizing agent capable of oxidizing mineral salts according to the invention in the presence of a substrate of wood, bamboo, leather, cellulose, and other suitable substrates. Preferred oxygen sources are peroxides, compounds that include the peroxy (—O—O—) group. Peroxides form hydrogen peroxide upon solution in water. The invention may employ any inorganic or organic peroxide, including those described in Kirk Othmer, Concise Encyclopedia of Chemical Technology , pp. 845-850 (1985), which is incorporated herein by reference. Thus, the oxygen source may be a superoxide or ozonide, or a peroxyacid. It may also be a hypochlorite or chlorine dioxide, although these are relatively toxic and unstable.
[0061] A person of ordinary skill may vary and control for the following parameters to obtain a desired result. The color-producing reactions and resultant color and textural appearance of the wood varies widely with the different minerals used in Solution A. They are reproducible, however, and may be selected as desired to provide a particular appearance. The effect may vary with the purity of the minerals used in Solution A. The examples below used Reagent Grade but Technical Grade or lower grades are suitable for a commercial application.
[0062] The effect varies with the oxygen sources in solution B. Sodium peroxide and hydrogen peroxide and combinations give desirable effects. Other inorganic and organic peroxides and oxygen sources are suitable.
[0063] The effect may vary with the source of water. The examples use purified water. Distilled water versus mineral-rich well water may result in slightly different effects. In general, however, the use of tap water or deionized water gives adequate results. In other cases, modifying the pH or ionic strength with additives may be desirable.
[0064] The effect may vary with the solution in which the minerals or peroxides are dissolved or suspended. In the examples below, water is used, but other liquids could be used, some with non-water-soluble minerals. Instead of a solution, the minerals could be dissolved or suspended in a gel, wax, lotion, or creme and rubbed into the wood or substrate, so long as adequate penetration results. The wood or substrate must also be susceptible to penetration by an appropriate oxygen source, and the vehicle must be compatible in that it does not interfere with the color-producing reaction.
[0065] The effect may vary with the concentrations of the solutions. Generally, more dilute solutions create lighter color density but in some cases they actually give the appearance of a different color.
[0066] The effects produced do not vary appreciably with the ambient temperature at which the solutions are applied. The process can be followed at any temperature above or even slightly below 32° F. or the freezing point, and the stained-wood is dry and ready to be top-coated (if desired) in less than an hour, depending on humidity and temperature conditions. For extremely low-temperature applications, minerals and/or oxidizing agents can be dissolved in alcohol or other non-water solutions. In the examples below, the tests took place at room temperature, but experiments at near-freezing temperatures seemed to create the same result. The invention can also be applied at upper extremes of temperature or high or low pressure, if appropriate.
[0067] Reactions and resultant color and textural appearance of the substrate vary with the substrate material. In the examples below, sugar pine was used but the method of the invention has been successfully applied to northern pine, ponderosa pine, alder, poplar, maple, oak, ash, cedar, cherry, walnut, obinji and other woods and, of course, the results vary widely with the color, tone, and character of each type of wood. Successful demonstrations have also been done on ply bamboo, cotton, leather, and masonry. Ply bamboo is a very hard wood product, does not stain well with conventional products but is susceptible to coloring according to the invention. Other substrates are suitable so long as they are made of a material capable of binding the mineral salt in the presence of the oxygen source according to the invention.
[0068] Effects may vary with the order of application of solutions A and B. In general, starting with B and finishing with A yields a similar color but less nuances of wood grain, which could be preferable in certain applications. In simulating aged wood, for example, the A solution should be applied first. For a non-aged appearance and an even color, the B solution can be applied first. It may be that applying B first makes for a more superficial penetration of the linked color in the wood, but this may be appropriate for thin substrates. With porous substrates, such as fabric or leather, it is preferable to soak the substrate in the solutions to ensure even staining.
[0069] The results also vary with the additives included in solutions A or B such as pigments or dyes, citric acid, bleaches, alcohols, solvents, thickeners, tableting agents, finishing agents such as an appropriate overcoat of acrylic and other resins or polyurethanes that might oxidize and seal the wood simultaneously. Alternatively, an over coat sealer may be applied over the stain. An overcoat may optionally be included into Solution B (or solution A if that is applied last).
[0070] Stained wood according to the invention has been subjected to accelerated weathering situations, exposure to sun, hot water, freezing temperatures, and submersion in water. It is resistant to fading and actually is made slightly darker or warmer in tone on exposure. These tests show that the product produces a remarkably permanent stain suitable for use by professionals and amateurs, for interior and exterior application.
EXAMPLES
[0071] In all the formulas below, Solution A is made up as a solution of mineral in water. Concentrations are given as percent (weight/volume), or the number of grams of mineral and the volume of water is given. Solution B is made up of a 15% (v/v) solution hydrogen peroxide or a 0.3% sodium peroxide solution (made from 3.0 grams per liter of water). In all these cases, the substrate is Sugar Pine unless specifically mentioned otherwise. Different woods or other substrates work equally well, but the colors are somewhat different. These experiments were conducted with an ambient temperature around 65-75 degrees F. Upon application of the B solution, color appeared in from less than one second to up to one minute. Experiments at different temperatures have only marginally different results. Different strengths of Solution B speed or slow the reaction, but result in similar end colors. The key variable determining the color is the mineral or minerals in Solution A.
[0072] In Examples 1-10, the given mass of mineral was dissolved in 1 liter water.
Example 1
[0073]
[0000]
Solution A:
0.25 g Silver Sulfate (Ag 2 SO 4 )
Solution B:
Sodium Peroxide
Result:
Medium density golden-brown
Example 2
[0074]
[0000]
Solution A:
2.0 g Iron (II) Chloride (FeCl 2 •XH 2 O) + 0.5 g Silver
Sulfate (Ag 2 SO 4 )
Solution B:
Sodium Peroxide
Result:
Medium density gray-brown, aged appearance
Solution B:
Hydrogen Peroxide
Result:
Medium density warm yellow-brown
Example 3
[0075]
[0000]
Solution A:
1.5 g Iron (II) Chloride
Solution B:
Hydrogen Peroxide
Result:
Light density warm brown with reddish tone
Example 4
[0076]
[0000]
Solution A:
1.5 g Iron (II) Chloride + 1.0 g Zinc Perchlorate
(Zn(ClO 4 ) 2 •6H 2 O)
Solution B:
Hydrogen Peroxide
Result:
Medium density orange-brown with dark brown to black
highlights in the crossgrain
Solution B:
Sodium Peroxide
Result:
Medium density gray with black in the crossgrain
Example 5
[0077]
[0000]
Solution A:
1.5 g Cerium III Perchlorate (Ce(ClO 4 ) 3 •6H 2 O)
Solution B:
Hydrogen Peroxide
Result:
Light to medium density yellow-brown
Example 6
[0078]
[0000]
Solution A:
2.0 g Iron (II) Perchlorate (Fe(ClO 4 ) 2 •6H 2 O)
Solution B:
Hydrogen Peroxide
Result:
Light to medium density warm brown, aged appearance
Example 7
[0079]
[0000]
Solution A:
2.0 g Iron (II) Perchlorate (Fe(ClO 4 ) 2 •6H 2 O) + 0.25 g
Silver Sulfate (Ag 2 SO 4 )
Solution B:
Hydrogen Peroxide
Result:
Medium density warm brown aged appearance
Solution B:
Sodium Peroxide
Result:
Medium density gray brown aged appearance
Example 8
[0080]
[0000]
Solution A:
1.5 g Iron (II) Sulfate (FeSO 4 •7H 2 O)
Solution B:
Hydrogen Peroxide
Result:
Medium density warm brown, aged appearance
Solution B:
Sodium Peroxide
Result:
Medium density warm gray
Example 9
[0081]
[0000]
Solution A:
0.5 g Silver Perchlorate (AgClO 4 •H 2 O)
Solution B:
Sodium Peroxide
Result:
Medium density warm brown, aged appearance
Example 10
[0082]
[0000]
Solution A:
1.0 g Iron (II) Sulfate + 0.5 g Silver Perchlorate
Solution B:
Hydrogen Peroxide
Result:
Medium density warm brown, aged appearance
Solution B:
Sodium Peroxide
Result:
Medium density gray brown aged appearance
Example 11
[0083]
[0000]
Solution A:
Copper Acetate, 1 gram diluted in 50 ml of
H 2 O
With Hydrogen Peroxide:
warm orange-brown, medium density
With Sodium Peroxide:
no reaction
Example 12
[0084]
[0000]
Solution A:
Iron(II) Chloride:
0.5 grams
and Silver Sulfate
0.5 grams in 50 ml H 2 O
With Hydrogen Peroxide:
gray-brown, medium density
With Sodium Peroxide:
orange brown, dark density
Example 13
[0085]
[0000]
Solution A:
Iron (II) Perchlorate:
8 grams
and Silver Sulfate
0.25 grams in 100 ml H 2 O
With Hydrogen Peroxide:
dark aged appearance
With Sodium Peroxide:
nearly black, ebony-like appearance
Example 14
[0086]
[0000]
Solution A:
Iron (II) Perchlorate:
4 grams
and Silver Sulfate
0.1 grams in 100 ml H 2 O
With Hydrogen Peroxide:
warm orange brown, medium density
With Sodium Peroxide:
warm reddish brown, medium density
Example 15
[0087]
[0000]
Solution A:
Iron (II) Perchlorate
4 grams
and Silver Sulfate
0.1 grams in 200 ml H 2 O
With Hydrogen-Peroxide:
warm gray aged appearance,
light density
With Sodium Peroxide:
reddish gray aged appearance,
light density
Example 16
[0088]
[0000]
Solution A:
Iron (II) Chloride
2.5 grams
and Silver Sulfate
0.5 grams in 150 ml H 2 0
With Hydrogen Peroxide:
minimal reaction
With Sodium Peroxide:
gray-black with silvery sheen, dark
density
With Sodium Peroxide
warmer gray-black with reddish tinge,
and Hydrogen Peroxide
dark density
mixed together:
Example 17
[0089]
[0000]
Solution A:
Iron (II) Perchlorate
1 gram in 200 ml H 2 O
With Hydrogen Peroxide:
gray brown aged appearance, light
density
With Sodium Peroxide:
orange brown aged appearance, light
density
Example 18
[0090]
[0000]
Solution A:
Iron (II) Chloride
1 gram in 200 ml H 2 O
With Hydrogen Peroxide:
gray brown aged appearance, light to
medium density
With Sodium Peroxide:
richer brown aged appearance, light to
medium density
Example 19
[0091]
[0000]
Solution A:
Iron (II) Chloride
1 gram in 400 ml H 2 O
With Hydrogen Peroxide:
gray brown aged appearance, light
density
With Sodium Peroxide:
warm brown aged appearance, light
density
Example 20
[0092]
[0000]
Solution A.
Magnesium Nitrate
1 gram in 250 ml H 2 O
With Hydrogen Peroxide:
minimal result
With Sodium Peroxide:
yellow appearance, medium density
Example 21
[0093]
[0000] Solution A: Cerium Nitrate 1 gram in 250 ml H 2 O With Hydrogen Peroxide: minimal result With Sodium Peroxide: yellow appearance, medium density
In all of the examples below the hydrogen peroxide is in a 15% solution and the Sodium Peroxide is made with 2 grams diluted in one liter H 2 O.
Example 22
[0094]
[0000]
Silver Perchlorate:
1.5 grams per liter H 2 O
Result on concrete:
With Hydrogen Peroxide:
no effect
With Sodium Peroxide:
gun metal gray to black
Example 23
[0095]
[0000]
Iron (II) Chloride:
2 grams per liter H 2 O
result with cotton cloth:
With Hydrogen Peroxide:
light gray
With Sodium Peroxide:
orange brown
Example 24
[0096]
[0000]
Iron (II) Chloride:
2 grams per liter H 2 O
result on pale unfinished leather:
With Hydrogen Peroxide:
warm golden brown
With Sodium Peroxide:
grayish tan
Example 25
[0097]
[0000]
Iron (II) Chloride:
2 grams per liter H 2 O
result on paper:
With Hydrogen Peroxide:
light gray
With Sodium Peroxide:
rich sepia
[0098] The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. Modifications and Variations of the above-described embodiments of the invention are possible without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.
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According to the invention, a metal salt and an oxygen source are applied to penetrate or impregnate a suitable substrate sequentially in effective amounts so as to react in contact with the substrate and produce a mineral compound fixed within the surface of the substrate. The inventive combination of a mutually compatible metal salt, oxygen source, and substrate brings about an in situ reaction, and modifies the substrate to bring about a lasting desired effect. The mineral compound that is produced according to the invention is linked to the substrate, is stable and long-lasting or permanent, and is immobilized or insolubilized in the substrate. The mineral compound is bound or contained within and on the surface of the substrate, so it may be said to be ingrained in the fibers or matrix of the substrate, or embedded within the substrate. The desired effect is preferably a color. A wide variety of metal salts may be used depending on the desired effect. The oxygen source is preferably a peroxide, and the substrate is preferably a cellulose product such as wood, cotton, or paper; leather; or masonry. The invention contemplates methods of treating substrates, treatment kits, and treated products. With wood products, the invention provides a water-based stain of low toxicity useful for soft woods.
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PRIORITY CLAIM
[0001] This application is a national stage application of International Application No. PCT/AU2005//001218, filed on Aug. 12, 2005 which claims priority to, and the benefit of, Australian Provisional Application No. 2004904549, filed Aug. 13, 2004, the entire content of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to concrete expansion joints. More particularly, the present invention relates to a support assembly for an expansion joint strip and a method for installing an expansion joint strip in a concrete slab.
BACKGROUND OF THE INVENTION
[0003] Concrete floors and paving typically comprise a number of concrete slabs. The concrete slabs are typically designed for movement relative to each other to avoid formation of cracks in the floor or paving which would otherwise form with thermal expansion and contraction of the concrete slab and movement of supporting foundations. Concrete slabs are typically separated from each other by concrete expansion joints which usually comprise a compressible expansion joint strip. Compressible expansion joint strips fill the gaps between concrete slabs while allowing movement toward and away from each other.
[0004] Devices for positioning an expansion joint strip and formation of a corresponding expansion joint between concrete slabs are disclosed in U.S. Pat. No. 6,598,364 B1 and Danley Construction Products Pty Ltd and Connolly Key Joint Pty Ltd websites www.danley.com.au and www.connollykeyjoint.com respectively. The corresponding expansion joint forming devices are typically cumbersome and time consuming to erect.
SUMMARY OF THE INVENTION
[0005] According to one aspect of the present invention there is provided a support assembly for an expansion joint strip, said assembly comprising: an elongate base strip including at least two laterally spaced locating walls; a plurality of discrete support modules each being detachably connected to the locating walls at longitudinally spaced positions along the base strip; and means for adjusting the height of the expansion joint strip relative to at least one of the support modules.
[0006] Preferably the support assembly also comprises an expansion joint strip cover adapted to support the expansion join strip and being arranged to be supported by one or more of the support modules. More preferably each of the modules includes a U-shaped channel configured to cradle the expansion joint strip cover.
[0007] Preferably the height adjustment means includes a pin being designed to locate at one of a plurality of different height positions relative to the corresponding support module. More preferably the pin is received in one of a plurality of locating holes in the support module, the strip cover being designed to rest on the pin to support the expansion joint strip at the required height. Even more preferably the pin is enlarged at one end for press-fit engagement with said one of the locating holes.
[0008] Preferably the locating walls are each in the form of stiffening ribs designed to strengthen the base strip.
[0009] Preferably the support modules include a pair of spaced support legs each being perforated to promote the flow of concrete and encasing of said modules.
[0010] Preferably said locating walls include a pair of outer locating walls and a central locating wall. More preferably the base strip includes a groove or slot underlying the central wall and designed to allow lateral movement of the strip.
[0011] Preferably the support assembly also comprises another base strip joined to said base strip at an expansion joint juncture.
[0012] According to another aspect of the invention there is provided a method of installing an expansion joint strip in a concrete slab, said method comprising the steps of: providing an elongate base strip having at least two laterally spaced locating walls; providing a plurality of discrete support modules; fitting two or more of the support modules to the locating walls of the base strip at spaced longitudinal positions along the base strip; placing the expansion joint strip upon one or more of the modules and adjusting the height of said strip relative to at least one of said modules; and pouring concrete to at least partly bury the base strip, the support modules and the expansion joint strip.
[0013] Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0014] A preferred embodiment of the present invention will now be described, by way of example only, with reference to the following figures in which:
[0015] FIG. 1 is a partially exploded perspective view of one example of an expansion joint strip support assembly of the present invention.
[0016] FIG. 2 is an end elevational view of the expansion joint strip support assembly of FIG. 1 in its assembled condition.
[0017] FIG. 3 a is a perspective view of a base strip from the assembly of FIG. 1 .
[0018] FIG. 3 b is an end elevational view of the base strip of FIG. 3 a.
[0019] FIG. 4 is an end elevational view of the base strip of FIG. 3 a used to directly support a compressible expansion joint strip.
[0020] FIG. 5 is a perspective view of an alternative example of an expansion joint strip support assembly of the present invention.
[0021] FIG. 6 a is a perspective view of an expansion joint strip support assembly similar to that of FIG. 5 .
[0022] FIG. 6 b is an end elevational view of an alternative strip cover to that of FIG. 6 a.
[0023] FIG. 7 is an end elevational view of the expansion joint strip support assembly of FIGS. 5 and 6 but without a concrete slab locating rod.
[0024] FIG. 8 is an end elevational view similar to that of FIG. 7 except that it includes the concrete slab locating rod of FIGS. 5 and 6 .
[0025] FIG. 9 is an end elevational view of the expansion joint strip support assembly of FIG. 1 attached to another expansion joint strip support assembly.
[0026] FIG. 10 is a perspective view of an expansion joint strip support assembly similar to that of FIG. 9 attached via an alternative attachment bracket.
[0027] FIG. 11 is a perspective view of another alternative example of an expansion joint strip support module of the present invention.
[0028] FIG. 12 is a perspective view of 2 base strips of FIG. 1 attached end to end.
DETAILED DESCRIPTION OF THE INVENTION
[0029] FIG. 1 to 3 b show an expansion joint strip support assembly of the present invention in the form of support assembly 10 . The support assembly 10 comprises an expansion joint strip support module in the form of support module 12 , a base strip 14 and an expansion joint strip cover in the form of strip cover 16 . The support module 12 attaches to the base strip 14 as shown in FIGS. 1 and 2 which is described in detail below. FIGS. 1 and 3 a show only a portion of the entire length of the base strip 14 . The base strip 14 ranges from about 4 metres to about 6 metres in length. Support modules 12 are positioned along the length of the base strip 14 and attached to the base strip so that they are longitudinally spaced apart by about 400 mm. With support modules 12 spaced in this manner along the base strip 14 they are each able to support, as described below, a portion of an expansion strip in the form of a compressible expansion joint strip 20 . The expansion joint strip 20 is typically a tar based compressible expansion strip. With the expansion joint strip 20 supported as shown in FIG. 2 it is supported for separation of concrete slabs 250 and 252 which are subsequently poured on either side of the compressible expansion joint strip 20 . The support module 12 is suitable for concrete slabs of any thickness.
[0030] The support assembly 10 shown in FIG. 2 is assembled first by placing the base strip 14 on the floor or ground which is to support the concrete slabs 250 and 252 . The floor may, for example, be elevated. The base strip 14 is positioned on the floor or ground so that it's aligned with the space between the proposed concrete slabs 250 and 252 . Other base strips 14 are also positioned on the floor or ground both parallel with and normally to other base strips to correspond with the predetermined arrangement of expansion joints. If the base strips are positioned on the ground they are usually attached via pegs, for example, pegs 15 (see FIGS. 1 and 2 ) as shown in FIG. 2 . Plastic sheet, (not shown) are then laid over the base strips and slits are cut in the plastic to enable locating walls of the base strip which are described below to pass up through the plastic sheets. The plastic sheets function to seal the floor or ground to prevent moisture seeping upwardly into the concrete slab. Once all of the base strips 14 relating to a specific surface area have been appropriately positioned, reinforcing mesh (not shown) is then positioned appropriately on top of the base strips 14 . For some applications the mesh is cut above the locating walls so that it is not exposed after concrete is poured but is entirely embedded in the concrete. The support modules 12 are then positioned above the base strip 14 to which they are to be attached so that they attach to the base strip 14 as shown in FIGS. 1 and 2 by passage through holes of the mesh (not shown). The support modules 12 also function to attach the plastic sheets to the base strips 14 .
[0031] The position of an upper surface 136 of the compressible expansion joint strip 20 relative to the upper surface 104 of the base strip 14 is adjusted by passing a locating pin 138 through opposed holes 38 and 40 of the U-shaped channel 24 as shown in FIG. 2 . The upper surface 136 of the compressible expansion joint strip 20 can be used as a guide for forming an upper surface of the concrete slabs 250 and 252 . The means of adjustment involving the opposed holes 38 and 40 and the locating pin 138 can therefore be used, for example, to correct for any unwanted variation in the floor or ground height or alternatively to produce a sloping upper surface 136 to allow for drainage.
[0032] Features of the support module 12 , base strip 14 and strip cover 16 will be described in more detail before providing a more detailed description of assembly of the support assembly 10 . The support assembly 10 comprises an expansion joint strip locating portion in the form of a U-shaped channel 24 and support legs in the form of planar legs 26 and 28 . The U-shaped channel 24 comprises opposed side walls 32 and 34 and an adjoining base 36 . The U-shaped channel 24 also includes adjustment means in the form of opposed holes 38 and 40 formed in respective side walls 32 and 34 .
[0033] The planar leg 26 comprises 3 adjoining planar leg portions in the form of adjoining leg portions 46 , 48 and 50 . The adjoining planar leg 28 similarly comprises 3 adjoining planar leg portions in the form of adjoining leg portions 50 to 54 and 56 . Although not shown in FIG. 1 , planar leg portions 26 and 28 are perforated as described below in relation to support module 142 (see FIGS. 5 and 6 a ) for flow of concrete or other cementitious material into the space underneath the leg portions 26 and 28 . In the support module 12 the adjoining leg portions 50 and 56 are integrally formed with the base 36 of the U-shaped channel 24 . The other adjoining leg portions of the support module 12 are also integrally formed with the adjoining leg portions 50 and 56 . The side walls 32 and 34 of the U-shaped channel 24 are also integrally formed with the base 36 and the adjoining leg portions 50 and 56 . In one alternative embodiment of the support module 12 the base 36 is V-shaped so that its longitudinal axis is positioned below its upper longitudinal edges. In this alternative embodiment a corresponding strip cover is identical to strip cover 16 except that its base is also v-shaped. The support module 12 is manufactured by cutting a corresponding extrusion into 80 mm lengths. It will be appreciated by persons skilled in the relevant art that the support module 12 can be manufactured by other means and could for example be injection moulded or formed from separate components corresponding to the adjoining leg portions, base 36 and side walls 32 and 34 .
[0034] The adjoining leg portions 46 and 52 comprise attachment means for attachment to the base strip 14 . The attachment means of the adjoining leg portions 46 and 52 is in the form of respective locating slots 60 and 62 . Each of the locating slots 60 and 62 comprises locating slot walls 64 and 66 , and 68 and 70 respectively. The walls 64 , 66 , 68 and 70 are resiliently deformable for attachment to the base strip 14 . Formed on the inner surface of walls 64 and 70 are engaging surfaces in the form of barbs 74 . The barbs 74 are designed for engagement with corresponding engaging features of the base strip 14 which are described below.
[0035] The base strip 14 is also extruded and includes 2 outer locating walls in the form of outer locating walls 80 and 82 and a central locating wall in the form of central locating wall 84 . The outer and central locating walls are the attachment means of the base strip 14 for attachment to a support module such as support module 12 . The central locating wall may also function to elevate the reinforcing mesh which reduces or in some cases may replace the need for reinforcing mesh support cradles.
[0036] Outer locating walls 80 and 82 include on their outer surfaces 86 and 88 respectively engaging surfaces corresponding to the engaging surfaces of the locating slots 60 and 62 in the form of barbs 90 . As can be seen from FIGS. 1 and 2 the barbs 74 and 90 are designed to slide over each other as the outer locating walls 80 and 82 are forced into the corresponding respective locating slots 60 and 62 . Insertion of the locating walls into the slots results in the corresponding locating slot walls resiliently separating and then resiliently compressing against the locating walls when the respective barbs 74 and 90 are appropriately engaged in the position shown in FIG. 2 . Relative orientation of the barbs 74 and 90 means that withdrawal of the outer locating walls 80 and 82 from the corresponding respective locating slots 60 and 62 is resisted by engagement of the respective barbs as shown in FIG. 2 .
[0037] The height of the outer locating walls 80 and 82 and the depth of the corresponding respective locating slots 60 and 62 is such that the locating walls are fully received within the corresponding locating slots before free ends 100 and 102 of the planar legs 26 and 28 (see FIG. 2 ) contact an upper surface 104 of the base strip 14 .
[0038] The base strip 14 includes outer regions in the form of recessed regions 110 and 112 . The recessed regions 110 and 112 have corresponding respective recessed surfaces 114 and 116 which are offset relative to the upper surface 104 of the base strip 14 . The base strip 14 also includes recess strips in the form of recess strips 120 and 122 which are formed in an underneath side of the base strip 14 . Finally, the base strip 14 includes a groove in the form of a V-shaped groove 106 (see FIGS. 1 and 2 ) which is also formed in the underneath side of the base strip 14 and positioned directly beneath the central locating wall 84 . Referring to FIG. 3 b , the V-shaped groove 106 in an alternative embodiment coincides with a deflection slot 108 . The V-shaped groove 106 and optional deflection slot 108 enable sides of the base strip 14 to deflect relative to each other in a plane which is substantially normal to a longitudinal axis of the base strip 14 . This ability to deflect enables the base strip 14 to accommodate movement in the ground or floor without affecting its integrity. The deflection slot 108 may extend the entire depth of the central locating wall 84 .
[0039] FIG. 4 shows an alternative use of the base strip 14 . In this alternative use the base strip 14 directly supports an assembled compressible expansion joint strip 20 and corresponding strip cover 16 by attachment of the expansion joint strip and strip cover directly to the central locating wall 84 . In this alternative use of the base strip 14 , the base strip 14 functions as an expansion joint strip support module. The central locating wall 84 functions as an expansion joint strip locating projection of that module while the support means of the expansion joint strip support module comprises the plates 85 and 87 which the central locating wall 84 is integrally formed with and which are positioned on either side of the central locating wall. This alternative use of the base strip 14 is used to form reduced depth concrete slabs consisting of concrete slabs 320 and 322 positioned either side of an expansion joint strip 324 .
[0040] The alternative use of the base strip 14 shown in FIG. 4 can also be used to top an existing concrete slab. The base strip 14 is positioned on top of an existing concrete slab 330 and attached to that slab via screws 332 . Pouring concrete on top of the base strip 14 then results in formation of the slabs 320 and 322 and the corresponding expansion joint 324 . Expansion joints similar to expansion joint 324 positioned on top of the existing concrete slab 330 can be used, as described above, to level concrete slabs formed on top of the existing slab 330 . This process can also be used to improve the finished surface of a concrete slab.
[0041] The alternative use of the base strip 14 shown in FIG. 4 can also be used to form full depth expansion joints by using strip cover and compressible expansion joint strip assemblies described below in relation to the support assembly 140 . The strip cover 16 comprises a U-shaped channel 130 having opposed side walls 132 and an adjoining base 134 . The strip cover 130 is designed to cover the compressible expansion joint strip 20 as shown in FIGS. 1 and 2 . With the strip cover 130 covering the compressible expansion joint strip 20 it can be placed into the U-shaped channel 24 for support by the support module 12 . Although the strip cover 16 is designed to increase the rigidity of the compressible expansion joint strip 20 which, as described below, makes it suitable for directly inserting an assembled strip cover and expansion joint strip into wet concrete, the strip cover 16 is also flexible in a plane which is aligned with the adjoining base 134 . The strip cover 16 can therefore be used for forming non linear expansion joints.
[0042] An alternative expansion joint strip support assembly in the form of support assembly 140 is shown in FIGS. 5 to 8 . The support assembly 140 includes a support module 142 , base strip 144 and strip cover 146 . The support module 142 differs from the support module 12 and is described in detail below. The base strip 144 is identical to the base strip 14 and its features are referenced using the reference numerals of base strip 14 . The strip cover 146 is the same as the strip cover 16 except that it is deeper for receipt of a deeper compressible expansion joint strip 148 (see FIGS. 6 a , 7 and 8 ). The strip cover 146 may also include holes (not shown) for receipt of locating rods 150 , as described below.
[0043] The support assembly 140 also includes a concrete slab locating rod 150 (see FIGS. 5 , 6 a and 8 ). The locating rod 150 also forms part of the support assembly 10 and the description relating to the locating rod 150 in relation to its use with the support assembly 140 also applies to use of the locating rod 150 with the support assembly 10 .
[0044] The support module 142 is formed as described above in relation to the support module 12 by cutting 80 mm lengths from a correspondingly shaped extrusion. The support module 12 includes a planar leg 160 which is essentially identical to the planar leg 26 of the support module 12 . The planar leg 160 includes intersecting leg portions 162 , 164 and 166 . The intersecting leg portion 162 includes a locating slot 170 formed between locating slot walls 172 and 174 . Barbs 176 are formed on an inner surface of the locating slot wall 172 as described above in relation to the support module 12 .
[0045] The support module 142 includes an expansion joint strip locating portion in the form of U-shaped channel 180 . The U-shaped channel 180 includes side walls 182 and 184 and an adjoining base 186 . The side wall 182 extends from the base 186 upwardly beyond the intersecting leg portion 166 . An upper end of the extension of the side wall 182 is in the form of a strip cover locating projection 190 .
[0046] The support module 142 also includes attachment means in the form of a locating slot 192 formed between a locating slot wall 194 and an outer surface of the side wall 182 and its corresponding upward extension. Formed on the inner surface of the locating slot 192 are engaging surfaces in the form of barbs 196 . The locating slot 192 is designed for engagement with the central locating wall 84 of the base strip 144 as described in relation to the locating slot 170 .
[0047] The side wall 182 and its corresponding upward extension which connects to the intersecting leg portion 166 , as well as the base 186 of the U-shaped channel 180 also functions as a second support leg of the support module 142 .
[0048] In addition to being a different height than the strip cover 16 of the support assembly 10 , the strip cover 146 includes an axial flange 200 . The axial flange 200 attaches to an outer surface of a side wall 202 of the strip cover 146 . The axial flange 200 provides a module locating slot 204 for receipt of the strip cover locating projection 190 of the support module 142 . The axial flange 200 prevents the strip cover 146 and corresponding compressible expansion joint strip 148 from tilting away from the strip cover locating projection 190 . The axial flange 200 also stiffens the strip cover 146 to prevent distortion, particularly in a plane which is parallel with the base 186 of the U-shaped channel 180 . The axial flange 200 also increases torsional stiffness of the strip cover 146 about its longitudinal axis.
[0049] An alternative strip cover 147 is shown in FIG. 6 b . This alternative strip cover is designed to locate an expansion joint strip in the form of compressible expansion joint strip 149 which is typically known to people skilled in the relevant art as a “metal cracker strip”. Compressible expansion joint strip 149 includes a metal strip 152 and a compressible strip 154 .
[0050] The strip cover 16 of the support assembly 10 and the strip covers 146 and 147 of the support assembly 140 can be used independently of the corresponding support modules 12 and 142 and base strips 14 and 144 to form an expansion joint. The strip covers 16 , 146 and 147 sufficiently increase the rigidity of the corresponding respective compressible expansion joint strips 20 , and 148 and 149 to enable the assembled strip covers and compressible expansion joint strips to be inserted into wet concrete. Advantages provided by remaining components of the support assemblies 10 and 140 as described throughout the specification may be considered unnecessary for a particular application. If so, this alternative use of the assembled strip covers and compressible expansion joint strips enables expansion joints to be formed more easily and cost effectively.
[0051] The locating rod 150 includes a locating sleeve 206 and a corresponding rod 208 . As can be seen from FIG. 8 an end 210 of the locating rod 208 is positioned close to a blind end 212 of the locating sleeve 206 . Referring to FIGS. 5 and 6 a the locating sleeve 206 has lower and upper walls 214 and 216 . The distance between inner surfaces of these lower and upper walls is less than the separation of internal surfaces of the walls which join the lower and upper walls 214 and 216 . Referring to FIG. 8 , the locating sleeve 206 limits upward and downward movement of the round locating rod 208 but allows some movement in a lateral direction.
[0052] The locating sleeve 206 includes a locating rod locator 220 for attachment of the locating rod 206 to the base strip 144 . The locating rod locator 220 is integrally formed with the locating sleeve 206 and includes at an end remote from the locating sleeve a locating slot 222 which is described in the relation to the locating slot 170 . The locating slot 222 is designed for removable attachment to the locating slot wall 172 as described above in relation to the location slot 170 and locating slot wall 172 .
[0053] For some applications the strip cover 146 does not include holes in its walls but is marked for formation of holes through its walls and also through the compressible expansion joint strip 148 located between the strip cover side walls. These holes (not shown) are designed for passage through the strip cover 146 and corresponding compressible expansion joint strip 148 of the locating rod 150 . The holes in the strip cover and compressible expansion joint strip are usually more easily formed prior to assembly of the strip cover and support module 142 using an appropriate tool.
[0054] The support module 142 is attached to the base strip 144 as described above in relation to the support assembly 10 . The strip cover 146 or alternative strip cover 147 and associated respective compressible expansion joint strip 148 or 149 is then fitted into the U-shaped channel 180 so that the strip cover locating projection 190 slides upwardly through the module locating slot 204 . With the strip cover 146 and support module 142 assembled as shown in FIGS. 5 to 8 walls of the strip cover 16 are clamped together via a clip 340 as shown in FIG. 6 a . The clip 340 prevents walls of the strip cover 146 separating if concrete being poured on one side of an expansion joint flows on top of the expansion joint strip. A similar clip (not shown) can be designed for use with the alternative strip cover 147 .
[0055] The locating rod 150 is inserted through holes in the strip cover and expansion joint strip 148 and then attached to the base strip 144 as shown in FIGS. 5 , 6 a and 8 . To prevent removal of the compressible expansion joint strip 148 it can be screwed to the corresponding strip cover 146 and the strip cover locating projection 190 by screws 260 (see FIG. 8 ).
[0056] Referring to FIGS. 5 and 6 a the intersecting leg portions 164 and 166 have perforations in the form of round holes 230 and 232 and square and rectangular holes 234 and 236 . These holes ensure that concrete or other cementitious material flows into the space underneath the intersecting leg portions 164 and 166 as it is poured onto the base strip 144 and against side wall 202 of the cover strip 146 to form slab 240 (see FIGS. 7 and 8 ) which abuts the side wall 202 .
[0057] After concrete is poured on both sides of the compressible expansion joint strip 148 it sets around the locating sleeve 206 and locating rod 208 . After the concrete slabs 240 and 242 set they will move relative to each other in response to changes in temperature and movement of the supporting floor or ground. Movement of the concrete slabs normally of the compressible expansion joint strip 148 is accommodated by compression and expansion of that strip and axial movement of the locating rod 208 within the locating sleeve 206 . Movement of the slabs 240 and 242 in a direction aligned with a longitudinal axis of the base strip 144 lies is accommodated by lateral movement of the locating rod 208 within the locating sleeve 206 .
[0058] As can be seen in FIGS. 7 and 8 the compressible expansion joint strip 148 extends the entire depth of concrete slabs 240 and 242 . This is in contrast to the compressible expansion joint strip 20 of the support assembly 10 (see FIG. 2 ) which only extends partway into the depth of concrete slabs 250 and 252 . The concrete slabs 250 and 252 join beneath the base 36 of the U-shaped channel 24 and above the central locating wall 84 . Contrastingly, the concrete slabs 240 and 242 of the support assembly 140 are completely separated by the corresponding compressible expansion joint strip 148 . The central locating wall 84 of the support assembly 10 (see FIG. 2 ) functions as a crack propagator to facilitate formation of a crack above the central locating wall 84 in the event that slabs 250 and 252 move. The central locating wall 84 therefore functions to limit the likelihood of cracks occurring within slabs 250 and 252 .
[0059] Termites typically pass from the ground into a building via its walls by passing upwardly through expansion joints of corresponding concrete slabs. The base strips 14 and 144 of FIGS. 1 and 5 prevent this from occurring by sealing the expansion joint from the corresponding supporting floor or ground.
[0060] Support assemblies 10 and 140 can be joined to corresponding support assemblies which, for example, extend normally of those support assemblies for intersection of corresponding expansion joints. One example of intersecting support assemblies is shown in FIG. 9 in relation to support assembly 10 . A support assembly ie 10 ′ appears on the left of the support assembly 10 . A compressible expansion joint strip 20 ′ of the support assembly 10 ′ extends normally of the compressible expansion joint strip 20 of the support assembly 10 . Referring to FIGS. 1 and 9 , material from an underneath surface of end region 270 of the base strip 14 ′ is removed to enable the end region 270 to sit on top of recessed surface 114 of the base strip 14 . Material is removed or checked out from the end region 270 so that an end 276 of the base strip 14 ′ either abuts or is positioned close to an abutting surface 278 of the base strip 14 .
[0061] With the support assemblies 10 and 10 ′ positioned as shown in FIG. 9 the corresponding base strips 14 and 14 ′ are attached relative to each other using a base strip locator in the form of base strip locator 280 . The base strip locator 280 includes a locating slot 282 and another locator in the form of base strip locating lug 284 . The locating slot 282 has the features described in relation to locating slots 60 and 62 and is designed for attachment to the outer locating wall 80 as described above in relation to the locating slot 60 and outer locating wall 80 . The locating lug 284 is designed to sit above the upper surface 104 of the base strip 14 ′ and locate the end region 270 of the base strip 14 ′ between the locating lug 284 and the recessed surface 114 of the base strip 14 . The strip covers 16 and 16 ′ of the respective support assemblies 10 and 10 ′ are attached via an angled bracket 290 .
[0062] The base strip locator 280 may, for example, in place of the base strip locating lug 284 include another locating slot (not shown) identical to the locating slot 282 but designed for attachment to outer locating walls 80 ′ or 82 ′ of the base strip 14 ′.
[0063] FIG. 10 corresponds to FIG. 9 and includes angled brackets 350 and 352 in place of the angled bracket 290 . FIG. 10 also shows that part of the outer locating wall 80 of the base strip 14 has been removed to provide an unobstructed region adjacent the central locating wall 84 ′ of the base strip 14 ′ which extends through to the central locating wall 84 of the base strip 14 .
[0064] FIG. 11 shows a support module 300 which is effectively identical to the support modules 12 and 12 ′ except that it includes intersecting U-shaped channels 302 and 304 . The support module 300 therefore provides alternative means to that described in relation to FIGS. 9 and 10 to join compressible expansion joint strips that extend normally of each other. Intersecting base strips are joined as described above in relation to base strips 14 and 14 ′ of FIGS. 9 and 10 . The compressible expansion joint strip (not shown) which is received within the U-shaped channel 304 would normally extend continuously through the intersection with the U-shaped channel 302 and compressible expansion joint strips of channel 302 would normally abut the continuous expansion joint strip.
[0065] Support assemblies 10 and 140 can also be joined to corresponding support assemblies which are aligned with those support assemblies for end to end connection of corresponding expansion joints. End to end connection of base strips 14 is shown in FIG. 12 . This end to end connection includes an end to end base strip coupling 360 . The base strip coupling 360 includes barbs 362 which are designed for removable attachment to locating walls 80 , 82 and 84 of the base strip 14 as described above in relation to the support assemblies 10 and 140 .
[0066] Support assemblies 10 and 140 of these embodiments of the present invention provide a number of advantages:
[0067] (a) quick and easy assembly involving placement of freestanding integrally formed support modules 12 and 142 .
[0068] (b) sealing of an expansion joint from underneath abutting concrete slabs to prevent termites or moisture passing upwardly through the expansion joint; and
[0069] (c) quick, easy and discrete adjustment of upper surfaces of the compressible expansion joint strips 20 and 148 .
[0070] All publications mentioned in this specification are herein incorporated by reference. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed anywhere before the priority date of each claim of this application.
[0071] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. For example, an inverted T-shaped support leg may replace the planar legs 26 and 28 of the support assembly 10 , in which case, the base strip 14 would not include the central locating wall 84 . This alternative support leg could, for example, attach to the adjoining base 36 of the U-shaped channel 24 . The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
[0072] It should be understood 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 can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
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In one aspect of the present invention there is provided an expansion joint strip support module 12 comprising an expansion joint strip locating portion 24 adapted to locate an expansion joint strip 20 and one or more support means 26 and 28 integral with and arranged to support the expansion joint strip locating portion.
In a further aspect of the present invention there is provided an expansion joint crack forming device comprising: an elongate base strip 14 being adapted to extend along a proposed expansion joint; and a crack forming projection 84 connected to the base strip 14 and designed to form a cavity in a concrete slab which is to be formed on top of the base strip 14 , the crack forming projection 84 being positioned to promote cracking of the concrete slab along the proposed expansion joint.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/367,649 filed Feb. 14, 2003, now U.S. Pat. No. 7,153,244.
TECHNICAL FIELD
This invention relates to a selectorized dumbbell having a selector that the user can manipulate to adjust the weight of the dumbbell. More particularly, this invention relates to a dumbbell using readily available commodity, cast iron weights in the manufacture thereof.
BACKGROUND OF THE INVENTION
The weight training field includes many machines sold under various names, such as Cybex, that are built to perform various weight training exercises. For example, in a Cybex weight training system, there might be one machine for doing a shoulder press exercise, another machine for doing a triceps press exercise, yet another machine for doing a biceps curl exercise, and so on. Each machine typically includes a stack of weights and a selector comprising an insertable pin that can be inserted beneath a particular weight in the stack. When the exercise is performed, it is performed against a resistance comprising all the weights in the stack that are located above the pin while the weights in the stack below the pin are left behind. By moving the pin to different positions in the stack, the user can adjust or vary the exercise mass.
The above described weight stack and pin structure is often referred to in the weight training art as a selectorized weight stack. The term “selectorized” means there is a selector which the user can manipulate to pick up and use a desired number of weights from the weight stack.
Selectorized dumbbells are known which comprise a set of weights located in two spaced apart stacks of weight plates. The weight plates in each stack can be separate from the weight plates in the other stack so that each weight plate forms a single weight. Alternatively, one weight plate in one stack can be joined to one weight plate in the other stack so that a single weight is formed by the pair of joined weight plates. In either of these designs, the weight plates in each stack are nested against one another with a gap or space being provided between the stacks of weight plates.
The selectorized dumbbell further comprises a handle that can be dropped down between the stacks of weight plates. At least one selector is provided to allow the handle to be coupled to a desired number of weight plates from each stack so that the desired number of weight plates are loaded from each stack onto either end of the handle. The selector can comprise a pin that is inserted beneath a selected weight or a movable selector carried on the handle that is slidable or rotatable relative to the handle to pick up different numbers of weight plates. The selector is manipulated by the user, e.g. by changing the position of the pin or by sliding or rotating the selector, to vary or adjust the amount of weight carried by the handle of the dumbbell.
After a weight adjustment operation is performed by the user, the user can pick up the dumbbell by lifting up on the handle of the dumbbell to lift the handle of the dumbbell, along with all the weight plates attached to either end of the handle, from between the remaining weight plates in each stack. The remaining or non-selected weight plates will simply remain in each stack in whatever stand or rack is provided for their storage. The user can then exercise with the dumbbell in a normal fashion. Following such exercise, the user can replace the handle of the dumbbell and the attached weights by dropping the dumbbell back into the space of gap formed between the remaining weights in the two stacks thereof.
One type of selectorized dumbbell is shown in U.S. Pat. No. 5,637,064 issued to the Applicants hereof. Other types of selectorized dumbbells are shown in U.S. Pat. Nos. 4,529,198, 6,149,558, 6,228,003 and 6,416,446.
Selectorized dumbbells have been manufactured with custom weight plates having a solid, plate-like form. In those selectorized dumbbells where the weight plates in the two stacks are joined together in pairs by connecting members such as side rails, the connecting members are often welded to the weight plates to form the connection. In those selectorized dumbbells where the weight plates in each stack comprise individual weights, it is not necessary to weld or attach pairs of weight plates to each other. Nonetheless, the weight plates again typically have a solid, plate-like form and must be provided with some type of means, such as a cut-out, a recess, a lobe, etc., that cooperates with the selector to allow the weight plate to be picked up and raised by the handle when the selector is positioned to select the weight plate. Thus, selectorized dumbbells when manufactured and shipped by the manufacturer are shipped as a complete unit, weights and all.
It is relatively expensive to ship selectorized dumbbells to a distributor, retailer or purchaser due to the weight of the dumbbell. In addition, shipping costs are expected to increase over time. Thus, there is a need in the art to provide a selectorized dumbbell which would be less costly to ship, but this need is inconsistent with the fact that such dumbbells as known in the art require custom manufactured weight plates as described above.
SUMMARY OF THE INVENTION
One aspect of this invention relates to a selectorized dumbbell which comprises a handle and a plurality of weights that can be nested together forming a nested first stack of weight plates and a nested second stack of weight plates. The first and second stacks of weight plates are separated by a gap that is large enough to accommodate at least a portion of the handle therebetween. A selector is movable by the user between different positions to allow a desired number of weight plates from each of the first and second stacks to be coupled to either end of the handle when the handle portion is located in the gap between the first and second stacks and the selector is manipulated by the user. Each weight comprises at least one weight plate having a height and a width. Each weight plate is removably attached to a carrier. The carrier extends over at least half the height of the weight plate when the weight plate is attached thereto.
Another aspect of this invention relates to a selectorized dumbbell which comprises a handle and a plurality of weights that can be nested together forming a nested first stack of weight plates and a nested second stack of weight plates. The first and second stacks of weight plates are separated by a gap that is large enough to accommodate at least a portion of the handle therebetween. A selector is movable by the user between different positions to allow a desired number of weight plates from each of the first and second stacks to be coupled to either end of the handle when the handle portion is located in the gap between the first and second stacks and the selector is manipulated by the user. Each weight comprises at least one weight plate. Each weight plate is removably attached to a carrier. Each carrier includes an elongated tongue or tang on which the weight plate is carried, the tongue or tang extending at least from a center of the weight plate outwardly towards a peripheral edge of the weight plate.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will be described more completely in the following Detailed Description, when taken in conjunction with the following drawings, in which like reference numerals refer to like elements throughout.
FIG. 1 is a side elevational view of a first embodiment of a selectorized dumbbell according to this invention;
FIG. 2 is a cross-sectional view of the selectorized dumbbell of FIG. 1 , taken along lines 2 - 2 in FIG. 1 ;
FIG. 3 is a side elevational view of the selectorized dumbbell of FIG. 1 , shown in exploded form to illustrate the handle of the dumbbell and the various weights that can be attached to the handle of the dumbbell;
FIG. 4 is a perspective view of one of the weights used with the selectorized dumbbell of FIG. 1 , particularly illustrating the attachment of the commodity weights to the weight frame;
FIG. 5 is a cross-sectional view of a portion of the weight shown in FIG. 4 , taken along lines 5 - 5 in FIG. 4 , particularly illustrating the attachment of one of the commodity weights to the weight frame;
FIG. 6 is a cross-sectional view similar to FIG. 5 , but illustrating another type of attachment for securing one of the commodity weights to the weight frame;
FIG. 7 is a top plan view of a typical commodity weight;
FIG. 8 is a side elevational view of a second embodiment of a selectorized dumbbell according to this invention;
FIG. 9 is an end elevational view of dumbbell 2 of FIG. 8 ;
FIG. 10 is a partial perspective view in exploded form of one end of dumbbell 2 of FIG. 8 , particularly illustrating portions of the weight frame and the attachment of a commodity weight to one end of the weight frame;
FIG. 11 is a partial cross-sectional view of a portion of the weight frame of dumbbell 2 of FIG. 8 , taken along lines 11 - 11 in FIG. 9 ; and
FIG. 12 is a cross-sectional view of a portion of the weight frame of dumbbell 2 of FIG. 8 , taken along lines 12 - 12 in FIG. 9 , particularly illustrating the attachment of a commodity weight to a portion of the weight frame.
DETAILED DESCRIPTION
Referring first to FIGS. 1-5 , a first embodiment of a selectorized dumbbell is illustrated generally as 2 . Dumbbell 2 as shown herein is similar to an existing product known as the Big Block which is manufactured and sold by Intellbell, Inc. of Owatonna, Minn., and which is shown in the Applicants' U.S. Pat. No. 5,769,762, which is hereby incorporated by reference. A summary description of dumbbell 2 will be provided herein only as needed to understand this invention. Reference may be had to U.S. Pat. No. 5,769,762 for a fuller and more complete description of dumbbell 2 .
Basically, dumbbell 2 includes a handle 4 and three nested weights 6 which can be selectively coupled to handle 4 using a selector 8 , namely a pin 10 that can be moved between three different positions on handle 4 to pass through one of three holes 12 on handle 4 . Weights 6 are provided with various sets of holes 14 and slots 16 in different combinations, a middle set c having three holes 14 c , a far right set b having two holes 14 b and one slot 16 b , and a far left set a having two slots 16 a and one hole 14 a . See FIG. 3 which illustrates the various sets a-c of holes 14 and slots 16 in the various weights 6 .
A desired number of weights 6 can be selectively coupled to handle 4 depending upon how selector 8 is used. If selector 8 is inserted through the middle hole 12 in handle 4 and through the middle set c of holes and slots, then all three weights 6 are coupled to handle 4 . If selector 8 is inserted through the far left hole 12 in handle 4 and thus through the far left set a of holes and slots, then only one weight 6 is coupled to handle 4 . If selector 8 is inserted through the far right hole 12 on handle 4 and thus through the far right set b of holes and slots, then two weights 6 are coupled to handle 4 . If selector 8 is not inserted through any holes 12 on handle 4 , then no weights 6 are coupled to handle 4 and handle 4 can be used by itself with the weight provided by handle 4 comprising the only exercise mass. The various sets a, b and c of holes and slots are further described in the Applicants' U.S. Pat. No. 5,769,762.
In dumbbell 2 of this invention, each weight 6 comprises an elongated weight frame 20 formed from an upwardly facing U-shaped channel 22 having a bottom wall 24 and front and rear walls 26 and 28 . In addition, each channel 22 includes an upwardly extending carrier 30 at each end that extends well above channel 22 . Carrier 30 is in the form of an upwardly extending tongue. See FIG. 4 . Channel 22 and carriers 30 are formed of metal, such as steel, with carriers 30 being formed of extended portions of bottom wall 24 that are bent upwardly relative to channel 22 . The various holes 14 and slots 16 in each set a, b and c thereof are duplicated in the opposed front and rear walls 26 and 28 of channel 22 as taught in the Applicants' U.S. Pat. No. 5,769,762.
A pair of commodity weights 32 are secured to carriers 30 of weight frame 20 , with one weight 32 being secured to each carrier 30 . In this regard, each carrier 30 includes a hub 34 that is punched out of each carrier 30 at the top of carrier 30 . Hub 34 sticks inwardly relative to carrier 30 to point towards the interior of weight frame 20 . Hub 34 is sized to be received in a central hole 36 of commodity weight 32 . Hub 34 also includes a hole 38 at the center of hub 34 to allow an attachment bolt 40 to pass therethrough.
A clamping member 42 is used on the other side of commodity weight 32 to clamp or secure commodity weight 32 on hub 34 of carrier 30 when attachment bolt 40 is tightened by a nut 43 . Clamping member 42 includes a protruding, saucer shaped central portion 44 and an annular peripheral rim 46 surrounding central portion 44 .
FIG. 5 shows hub 34 on carrier 30 passing into central hole 36 on commodity weight 32 . Saucer shaped portion 44 of clamping member 42 passes into central hole 36 on commodity weight 32 opposite to hub 34 to be able to abut and mate with hub 34 . Attachment bolt 40 passes through both clamping member 42 and hub 34 to firmly clamp the clamping member 42 to hub 34 when nut 43 is tightened. When so clamped, commodity weight 32 is held in the annular channel formed between peripheral rim 46 of clamping member 42 and the portions of carrier 30 surrounding hub 34 . Thus, a commodity weight 32 may be easily clamped to each carrier 30 of weight frame 20 using hub 34 provided on carrier 30 and a clamping member 42 .
FIG. 7 illustrates a typical commodity weight 32 of the type that is often used on traditional barbells or dumbbells. In such traditional barbells or dumbbells, a simple bar is used and a plurality of separate commodity weights 32 are provided. Each commodity weight 32 comprises a circular weight plate 35 having a central hole 36 . Hole 36 in commodity weight 32 allows commodity weight 32 to be slipped over one end of the bar. After a desired number of weights 32 have been so installed on each end of the bar, weights 32 can be held in place by a locking collar that is then placed and secured on each end of the bar.
In using traditional barbells or dumbbells of this type, the user adjusts the exercise mass by loosening and removing the locking collars from the ends of the bar and by then removing weights 32 from each end of the bar or by adding additional weights 32 to the bar. Each gym has a number of such weights 32 on hand simply for use on a bar to add weight to the bar. Weights 32 are referred to herein as “commodity weights” since they are a low cost commodity product typically manufactured in low wage, developing countries, such as China. Weights 32 are cast in large quantities from iron, currently more than 10 million pounds per year. They are shipped in large quantities from their country of origin and are readily available all around the world in standard weights, such as 1.25 pounds, 2.5 pounds, 5 pounds, and so on.
The Applicants have discovered that commodity weights 32 of this type are so inexpensive that the cost to purchase the weights locally is not much more or about the same as the cost to ship the same weights from the United States. Moreover, as shipping costs rise, the costs to ship relatively heavy dumbbells is expected to increase.
Accordingly, in a preferred method of manufacturing dumbbell 2 , weight frames 20 would be manufactured and shipped as part of dumbbell 2 but without any commodity weights 32 being attached thereto. The distributor, retailer or purchaser of the product would receive dumbbell 2 in this “unweighted” form. The distributor, retailer or purchaser of the product would then purchase a sufficient number of commodity weights 32 locally wherever the distributor, retailer or purchaser resides and would add such weights 32 to each weight frame 20 to complete dumbbell 2 . In this regard, dumbbell 2 would be shipped with enough clamping members 42 , bolts 40 and nuts 43 to allow a sufficient number of commodity weights 32 to be clamped to all the different weight frames 20 to complete dumbbell 2 .
The net result of this preferred manufacturing method of this invention is a lower cost product in the hands of the end user. The cost to purchase the product by the end user will be reduced by the costs that would have been incurred to manufacture or purchase custom weight plates as well as by the costs to ship all of the weights. This cost reduction will more than offset the cost at the other end to complete dumbbell 2 by having to purchase a sufficient number of commodity weights 20 . Essentially, at least the shipping costs that are usually associated with shipping the dumbbell should by and large be saved. This is an advantage to the user of dumbbell 2 by lowering the cost to own dumbbell 2 .
In addition, commodity weights 32 of different weights, such as 1.25 pounds or 2.5 pounds, typically have smaller diameters but a central hole 36 that is the same diameter to allow each weight 32 to be slipped onto the bar of a conventional barbell or dumbbell. Thus, the user can determine the incremental amount of adjustability for dumbbell 2 by selecting which sized commodity weight 32 to attach to carriers 30 . If a 1.25 pound commodity weight 32 is attached to carriers 30 , then dumbbell 2 will adjust in 2.5 pound increments. If a 2.5 pound commodity weight 32 is attached to carriers 30 , then dumbbell 2 will adjust in 5 pound increments. In addition, dumbbells 2 constructed with lighter commodity weights 32 will be dimensionally smaller in height and width than dumbbells 2 constructed with heavier commodity weights 32 .
Using commodity weights 32 to complete dumbbell 2 gives the end user a great deal of flexibility in custom tailoring dumbbell 2 to the user's desires. If a user wants a smaller, lighter dumbbell 2 that adjusts in smaller increments, the user completes dumbbell 2 with lighter commodity weights 32 . If a user wants a larger, heavier dumbbell 2 that adjusts in larger increments, the user completes dumbbell 2 with heavier commodity weights 32 . Moreover, the user can upgrade dumbbell 2 from a lighter to a heavier version simply by replacing the currently used commodity weights 32 with heavier commodity weights 32 without having to buy a set of new weight frames 20 .
Commodity weights 32 of the same size are available in slightly different thicknesses. For example, 2.5 pound weights 32 are currently made in 50 or so different foundries worldwide and vary in thickness from 0.565 inches to 0.615 inches. Weight frames 20 have to be manufactured to accommodate the thickest weight 32 in a particular size or range of sizes that are intended for use on weight frames 20 . In other words, clamping member 42 has to clamp to hub 34 and be able to receive the thickest commodity weight 32 . A compressible foam washer or other material could be supplied to use with thinner weights 32 to take up any play or gaps between thinner weights 32 and clamping member 42 .
Handle 4 of dumbbell 2 is shown in FIGS. 1-5 as having a pair of commodity weights 32 secured to either end thereof. In the case of handle 4 , weight frame 20 includes a downwardly facing U-shaped channel 48 instead of an upwardly facing U-shaped channel 22 . An upwardly facing U-shaped cradle 50 having spaced apart carriers 30 is fixed to the upper surface of downwardly facing channel 48 . A hand grip 52 extends between carriers 30 as shown in FIGS. 1 and 3 . Hand grip 52 carries a resilient cushion or cover to allow the user to better grip hand grip 52 of handle 4 .
In the case of handle 4 , carriers 30 will be formed with outwardly, rather than inwardly, extending hubs 34 which are inserted into central holes 36 of weights 32 . A similar clamping member 42 is used on the outside of carrier 30 to clamp weight 32 to carrier 30 . Instead of a bolt 40 and nut 43 for tightening clamping member 42 to hub 34 , a machine screw is used which can be screwed into a threaded bore (not shown) in the end of hand grip 52 to tighten clamping member 42 on carrier 30 of handle 4 . Thus, handle 4 can itself be provided with a pair of commodity weights 32 to allow handle 4 to be used for exercise by itself without any weights 6 being coupled to handle 4 by selector 8 .
Alternatively, handle 4 could be formed without any provision for coupling any commodity weights 32 to handle 4 . In this case, carriers 30 of handle 4 could simply be planar and solid without any outwardly protruding hub 34 for mounting a weight 32 . In this configuration, at least one weight 6 would normally be coupled to handle 4 to provide a minimum exercise mass. The exercise mass would be adjusted by selectively coupling additional weights 6 to handle 4 using selector 8 .
Other ways of coupling weights 32 to each end of weight frame 20 could be used. FIG. 6 shows one such alternative coupling.
Referring to FIG. 6 , each end of upwardly facing channel 22 of each weight frame 20 is no longer provided with an upwardly extending carrier 30 . Instead, each front and rear wall 26 and 28 of channel 22 is provided with a vertical slot 54 sized to receive the thickness of commodity weight 32 within slot 54 . Bottom wall 24 of channel 22 includes a tang 56 having a hole 58 in the top end of tang 56 . A flexible tie 60 is used to tie weight 6 in place in channel 22 with tie 60 passing through hole 58 in tang 56 and encircling the lower side of weight 32 with tie 60 being secured to itself by a connector 61 within central hole 36 of weight 32 . Such flexible ties 60 and connectors 61 as well as the tools used to secure the ends of tie 60 together at connector 61 are well known in the fastener art.
FIGS. 8-12 show an alternative form of selectorized dumbbell 2 ′ according to this invention. The type of dumbbell 2 ′ shown in FIGS. 8-12 is similar to an existing product known as the Power Block, which is manufactured and sold by Intellbell, Inc. of Owatonna, Minn., and which is shown in the Applicants' U.S. Pat. No. 5,637,064, which is hereby incorporated by reference. A summary description of dumbbell 2 ′ will be provided herein only as needed to understand this invention. Reference may be had to U.S. Pat. No. 5,637,064 for a fuller and more complete description of dumbbell 2 ′.
Basically, dumbbell 2 ′ includes a handle 4 ′ and a plurality of nested weights 6 ′ which can be selectively coupled to handle 4 ′ using a selector 8 ′. In the dumbbell 2 ′, each weight 6 ′ includes a pair of spaced apart weight plates 70 that are rigidly joined together by a pair of side rails 72 . Beginning with the innermost weight 6 ′, each weight 6 ′ has the weight plates 70 spaced apart a progressively greater distance and the side rails 72 located progressively lower to allow the weights 6 ′ to be nested together. The selector 8 ′ comprises a double pronged pin which can be slid beneath the side rails 72 of a selected weight 6 ′ by sliding the prongs of the pin into a selected groove 74 on each end of handle 4 ′. With selector 8 ′ so positioned, when the user lifts up on handle 4 ′, all weights 6 ′ whose side rails 72 are above selector 8 ′ will be lifted with handle 4 ′.
In the dumbbell 2 ′ as shown in the 064 patent, the individual weights 6 ′ were manufactured by taking two custom made weight plates 70 and by welding the side rails 72 to either side of the weight plates. In the embodiment of dumbbell 2 ′ of this invention as shown in FIGS. 8-12 , each weight 6 ′ is now made as a relatively lightweight weight frame 20 ′ that removably accept and retain a pair of commodity weights 32 . Thus, each weight 6 ′ when completed will comprise a weight frame 20 ′ with a commodity weight 32 in either end of weight frame 20 ′.
Each weight frame 20 ′ for each weight 6 ′ comprises a pair of planar, generally vertical carriers 30 ′ that are spaced apart the required distance to allow weight 6 ′ to be nested with the other weights 6 ′. Carriers 30 ′ are preferably molded or formed as a single piece out of a lightweight material, such as plastic. Each carrier 30 ′ has downwardly facing shoulders 64 along either side. Shoulders 64 of adjacent weights 6 ′ are at progressively lower elevations as shown in FIG. 8 , again to allow the completed weights 6 ′ to nest together.
Carriers 30 ′ are rigidly connected together by a pair of connecting rods or side rails 72 , preferably made of metal for durability. As shown in FIG. 11 , the end of each side rail 72 is simply bolted or screwed to shoulder 64 of the carrier by a screw or bolt 78 . The head of screw or bolt 78 is received in a recess 80 in carrier 30 ′ so that screw or bolt 78 does not protrude beyond the face of carrier 30 ′. When each end of side rail 72 is screwed to shoulders 64 on the same side of both carriers 30 ′, side rail 72 will extend between and unite the two carriers 30 ′ together in much the same way as the welded side rails joined the pair of weight plates shown in the 064 patent. There are two such side rails 72 for each weight 6 ′, one on either side of carrier 30 ′, uniting shoulders 64 provided on each side of carrier 30 ′.
The need for shoulders 64 that are progressively lower on adjacent weights is to allow side rails 72 to nest beneath one another as shown in FIG. 8 . While three weights 6 ′ have been shown in FIG. 8 , more could be provided with weights 6 ′ lying progressively outside of the three weights 6 ′ that are shown with such additional weights 6 ′ having progressively lower shoulders 64 and side rails 72 . As many weights 6 ′ could be provided as there are grooves 74 in each end of handle 4 , grooves 74 being suited for holding selector 8 ′ at different levels to couple different numbers of weights 6 ′ to handle 4 ′.
Each carrier 30 ′ includes a cavity 84 for receiving one commodity weight 32 therein. As shown most clearly in FIG. 10 , cavity 84 is provided in an inner face of carrier 30 ′ and is circular in shape. Cavity 84 includes a central, cylindrical hub 86 that is sized to be received within central hole 36 of commodity weight 32 . Hub 86 includes a central bore 88 for receiving a fastener 90 such as a bolt. Cavity 84 is deep enough to accommodate the thickest weight 32 in a size or range of sizes intended to be used on carriers 30 ′. Again, foam washers or rings or other material could be used in cavity 84 around hub 86 to accommodate any play if thinner weights 32 are used. Dumbbell 2 ′ as shown herein, when completed with commodity weights 32 , will desirably have a snug fit of commodity weights 32 in cavity 84 to avoid excess rattling and clanking and to impart a feeling of quality and safety to the end user.
Referring further to FIG. 10 , a commodity weight 32 is attached to carrier 30 ′ simply by lying weight 6 into cavity 84 with central hole 36 of weight 32 being concentrically received around the cylindrical central hub 86 in cavity 84 . A clamping member 42 ′, such as a flat washer 92 , is then abutted against the inner side of commodity weight 32 . Bolt 90 can be inserted through washer 92 , through central hole 36 in commodity weight 32 , and through central bore 88 of hub 86 . A nut 94 can be tightened on the free end of bolt 90 to tighten and clamp washer 92 against commodity weight 32 to hold commodity weight 32 in place in cavity 94 .
Referring to FIG. 12 , when commodity weight 32 is assembled to carrier 30 ′ in this fashion, the combined thicknesses of the various parts does not exceed the thickness of carrier 30 ′ to allow proper nesting of the various weights 6 ′ against one another. For example, nut 94 is received in a recess 96 in carrier 30 ′ so that it does not protrude beyond the adjacent face of carrier 30 ′. When tightened, washer 92 is flush or slightly inside of the other face of carrier 30 ′. Thus, each carrier 30 ′ on each weight 6 ′ can be abutted flush against the carriers 30 on the adjacent inside and outside weights 6 ′ in the nested array of weights 6 ′.
If nut 94 or bolt 90 should become loose, the fact that cavity 84 is in the inner face of carrier 30 ′ is beneficial. Weight 32 will still be trapped or retained between carrier 30 ′ and the outer face of carrier 30 ′ on the adjacent weight frame 20 ′ lying to the inside. This enhances safety of dumbbell 2 ′.
The alternative embodiment of a selectorized dumbbell 2 ′ as disclosed in FIGS. 8-12 has the advantages of the previous embodiment in that it can be completed by using readily available, low cost commodity weights 32 . Thus, dumbbell 2 ′ can also be shipped by the manufacturer with handle 4 ′, the various weight frames 20 ′ of the different weights 6 ′, selector 8 ′, and the necessary clamping washers 92 , bolts 90 and nuts 94 . Once dumbbell 2 ′ reaches a destination in the hands of a distributor, retailer or purchaser, it can be completed by purchasing the required number of commodity weights 32 locally and by clamping each commodity weight 32 in a cavity 94 of one carrier 30 ′. Following completion in this manner, dumbbell 2 ′ is ready for use in the normal method. The result is a dumbbell that is less expensive to manufacture and for the user to purchase.
Various modifications of this invention will be apparent to those skilled in the art. For example, the use of commodity weights 32 is not limited to selectorized dumbbells 2 , 2 ′ as shown herein, but could be used in any selectorized dumbbell including selectorized dumbbells where the selector is simply a movable part on the handle that cooperates with a recess, detent, cam lobe, etc. on each weight. In this event, the weights can still be manufactured as a weight frame that will receive a commodity weight 32 with commodity weight 32 supplying the mass that is needed as long at the weight frame carries the recess, detent, cam lobe, etc. that is required for cooperation with the selector.
Moreover, while the Applicants believe that it is most advantageous to purchase and unite commodity weights 32 to weight frames 20 , 20 ′ after weight frames 20 , 20 ′ are first shipped by the manufacturer to another destination, this is not necessary for every aspect of this invention. Weights 32 could be added to weight frames 20 , 20 ′ prior to shipment by the manufacturer as this still permits using readily available, low cost commodity weights 32 in the manufacture of selectorized dumbbells 2 , 2 ′.
Low cost, cast iron commodity weights manufactured for use on traditional barbells or dumbbells are a preferred type of commodity weight that can be used with respect to dumbbells 2 , 2 ′. However, large and heavy steel washers which are also readily available and relatively low cost can also comprise commodity weights 32 .
Thus, the scope of this invention is to be limited only by the appended claims.
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This invention relates to a selectorized dumbbell having a handle that can be dropped down between nested left and right stacks of weight plates. The weight plates can comprise individual weights or a pair of weight plates, one from each stack, can be connected together to form a single weight. A selector is provided to allow the user to select a desired number of weight plates from each stack and couple such weight plates to the handle to provide an adjustable weight dumbbell. Each weight includes a weight frame having at least one carrier to which a commodity weight can be fastened. The dumbbell can be shipped by the manufacturer with empty weight frames to reduce shipping costs. When the dumbbell with empty weight frames reaches a destination, the dumbbell can be completed by securing commodity weights to the carriers on the respective weight frames.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to our copending commonly assigned applications:
U.S. Ser. No. 08/817,690 (Corres. to PCT/FR94/01185 filed Oct. 12, 1994);
U.S. Ser. No. 08/817,689 (Corres. to PCT/FR95/01333 filed Oct. 13, 1995)
U.S. Ser. No. 08/817,528 (Corres. to PCT/FR95/01334 filed Oct. 12, 1995)
U.S. Ser. No. 08/817,968 (Corres. to PCT/FR95/01335 filed Oct. 12, 1995)
U.S. Ser. No. 08/817,426 (Corres. to PCT/FR95/01337 filed Oct. 12, 1995)
U.S. Ser. No. 08/817,438 (Corres. to PCT/FR95/01338 filed Oct. 12, 1995)
BACKGROUND OF THE INVENTION
1. Field of the Invention
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to a home digital audiovisual information recording and reproduction apparatus.
Audiovisual reproduction systems found generally in cafes or pubs and called jukeboxes are known. These devices are generally bulky including large storage capacities unsuited for home use. The object of this invention is to eliminate these defects of the prior art by proposing a device which allows a home user to acquire digital audiovisual data selections using his TV and to reproduce them using the TV screen for the visual part and the components of his stereo system for the audio part.
The first object of the invention is to propose an apparatus which allows selection and downloading of digital data, and reproduction of these digital data for domestic apparatus or use of the device for karaoke.
This first object is achieved with a home digital information audiovisual recording and playback apparatus developed around a microprocessor device linked via a digital interface to a display and by another interface to audio reproduction structure. The apparatus includes a telecommunications interface for downloading the digital data containing the audio selection or the video selection. The apparatus includes control structure that allows control of a display device and selection via a menu of one operating mode from among three in which the device either plays back data stored in its mass storage or allows recording of a new item of digitized data in its mass storage or mixes with the digitized data delivered by the mass storage of a piece of analog data delivered by a microphone.
A second object of the invention is to devise a modular apparatus which consequently allows continued development of the device to support recording of selections on a portable medium.
This object is achieved with a supplementary recording module connected by a specific interface to the primary apparatus, and a recording menu can be selected using the buttons of the control structure of the device of the primary apparatus.
According to another feature, the recording module allows production of portable recording media to be played on another digital audiovisual information playback unit.
Another object of the invention is to devise a modular device which allows the user to develop a design allowing storage of a plurality of audio or video or audiovisual information selections.
This object is achieved by a second mass storage module allowing the recording of a plurality of digitized audiovisual data.
Another object is to devise an apparatus which allows selection of audio or video or audiovisual digital data to be downloaded while enabling this information to be reproduced on the audio and video systems which he already owns.
This object is achieved by providing the home digital audiovisual information recording and reproduction apparatus with a central unit, a telecommunications interface linked to a connector and managed by the central unit, an electronic input control circuit managing a plurality of control buttons and a sensor of infrared or audio emission originating from a remote control box, an emitter of the same waves, an electronic extension controller circuit connected to a connector, an electronic audio controller circuit linked to audio output connectors for stereo systems and a microphone input connector, and an electronic video controller circuit linked to connectors of a video peripheral apparatus. The set of electronic circuits managed by the central processor utilizes a multitask operating system and a computer operating program stored in a battery backed-up static RAM, which is part of the electronic circuit of the central unit. The static battery backed-up RAM is used as storage for at least one selection of audiovisual digital data and a graphics control circuit, which controls a liquid crystal display device.
The final object is to devise a method of downloading which ensures effective payment and non-selection of audiovisual data by individuals not skilled in the domestic system.
This object is achieved by proving an operating mode of link selection control which allows downloading with a server once the user has given for example his credit card number and confirmed the set of his selection or selections by supplying a personal identification number. This object can also be achieved by any other method of payment such as: prepaid chip card or automatic billing on the subscriber phone bill.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of this invention will be illustrated by the following description with reference to the attached drawings in which:
FIG. 1 shows a schematic of the front and back of the apparatus according to the invention;
FIG. 2 shows a schematic of the general architecture of the electronic circuit comprising the apparatus;
FIG. 3 shows the organization of the multitask system managing the hardware and software;
FIG. 4 shows a flowchart describing the operation of the multitask operating system;
FIG. 5A shows a first version of the extension of the module for the apparatus of FIG. 1;
FIG. 5B shows a second version of the extension module for the apparatus of FIG. 1;
FIG. 6 shows a flowchart of the queuing of the selections;
FIG. 7 shows an organizational diagram of the database;
FIG. 8 shows an example of graphics display by the graphics module of the in service mode module;
FIG. 9 shows an example of graphics display by the graphics module of the new selection acquisition mode module;
FIG. 10 shows an example of graphics display by the graphics module of the browsing and selection mode module; and
FIG. 11 shows an example of graphics display by the graphics module of the category selection mode module.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferably, but in a nonrestrictive manner, the audiovisual reproduction system uses the aforementioned listed components.
The primary module is a high performance, PC microprocessor-compatible electronic device, with for example an Intel 80486 DX/2 type system which has storage means and the following characteristics:
compatibility with the local Vesa bus,
processor cache memory: 256 kB,
RAM of 32 MB or more, battery backed-up
high performance parallel and serial ports,
graphics adapter with video baseband, radio frequency (RF) band output and SCART connector,
type SCSI/2 bus type controller as the extension controller
Any other central unit with equivalent or superior performance can be used in the invention.
The central unit ( 106 ) controls and manages an audio control circuit ( 110 ), a telecommunications control circuit ( 104 ), an input control circuit ( 105 ), and a display control circuit ( 111 ).
Input controller ( 105 ) interfaces with a remote control ( 101 ) and control buttons ( 102 ) located on the front of the apparatus. Telecommunications controller ( 104 ) interfaces with various telecommunications hardware ( 103 ) to allow the system to use several media for communicating with the outside. Audio controller ( 110 ) is a D/A converter with multiple inputs/outputs to which the customer microphone and amplifier are connected. The video controller delivers the baseband and RF band video signals of the screens to be displayed. An extension controller ( 107 ) makes it possible to link the other modules ( 108 , 109 ) to the primary module.
A communications link between the primary module and the distribution center is also required. This link can be either a modem for a classical telephone line or a specialized line with a speed of at least 28.8 kbps or a link by parabolic antenna and satellite, or an ISDN telecommunications link or by coaxial cable or by MMDS-receiving antenna.
For radio wave type links, requests are made by classical telephone line.
Audio reproduction of the musical selections is done by a digital/analog converter circuit provided to support a large number of input sources while providing an output with an audio quality similar to a compact disk. The microprocessor multimedia audio adapter Sound Blaster SBP 32 AWE from Creative Labs Inc. is one example in which two buffers ( 1101 , 1102 ) are added.
Likewise, the control circuit of the display likewise includes two buffers ( 1111 , 1112 ).
Operation and management of the system are performed using, either control buttons ( 102 ) of the apparatus or remote control ( 101 ). An infrared remote control linked to an infrared sensor with serial adapter can be used in the system.
The diagram from FIG. 1 shows that the primary module has a RIAA stereo audio output, one microphone input for karaoke, a baseband and RF video output, and a connector for connecting it to the other expansion modules and a SCART connector.
Data are displayed on the TV set of the owner either by the RF connector or the baseband connector or the SCART connectors.
A battery system maintains the system memory when it is off. These long life batteries are recharged when electricity is supplied to the apparatus.
A thermally controlled and ventilated power supply powers the system. This power supply can be protected against surges and harmonics.
The electronic device is placed in a box which includes on one of its sides ( 11 ), for example, the back, an electric power cord with line socket ( 9 ), a double audio output ( 112 ) comprising RCA jack type sockets, a microphone input connector ( 113 ), a video connector ( 115 ) for the video baseband of the NTSC PAL or SECAM type and an RF radio frequency type output ( 114 ) and a SCART European connector ( 119 ). As FIG. 2 shows, audio output ( 112 ) and microphone input ( 113 ) are linked to audio controller card ( 110 ), RF video/atidio output ( 114 ) is linked to video controller card ( 111 ) and to audio controller card ( 110 ) via an RF modulator with M-B/G or L standards, for example, SCART connector ( 119 ) is linked to video controller card ( 111 ) and to audio controller card ( 110 ), video baseband ( 115 ) is linked to video controller card ( 111 ), extension connectors ( 116 ) are linked to extension controller card ( 107 ), one connector ( 118 ) of the telephone line type is linked to telecommunications circuit card ( 103 ) which is linked to telecommunications controller ( 104 ). Finally, the box includes on its front ( 10 ) a set of buttons ( 102 ) containing arrow ( 1021 ) which allows a cursor to move up, arrow ( 1022 ) which allows the cursor to move down, arrow ( 1023 ) which allows the cursor to move to the left, arrow ( 1024 ) which allows the cursor to move to the right, and finally central button ( 1025 ) allowing activation or validation and corresponding to a down event equivalent to a mouse, the arrows allowing movement of a cursor and corresponding to a drag event. Release of button ( 1025 ) corresponds to a button release event, i.e., up for a mouse. Front ( 10 ) includes a red button ( 1019 ) which allows the “purchase” function described below. The front also includes a liquid crystal screen ( 12 ) linked to a graphics controller card ( 120 ) to allow minimum display in the case in which the user does not connect a TV screen at the video or RF output. The side also contains a button ( 15 ) allowing adjustment of the volume of headphones connnected to a socket ( 14 ) for a hifi headset. Finally, device start and stop button ( 1020 ) is located on the front ( 10 ). A zone containing infrared sensor ( 13 ) itself connected to input controller card ( 105 ) allows reception of infrared signals from remote control ( 101 ). It is apparent that the type of sensor can be modified according to the type of remote control used without departing from the framework of the invention. Finally, the front may include a set of buttons which allows control of functions ordinarily used for CD playback, i.e., “pause” function ( 1026 ), “stop” function ( 1027 ), “read” function ( 1028 ), “return” function ( 1029 ), “advance” function ( 1030 ), “following” function ( 1031 ). These functions are linked to storage ( 108 ) and recording ( 109 ) modules when they are connected by extension connector ( 116 ) to extension card ( 107 ) as shown in FIG. 2 .
Besides these components, a microphone connected to audio controller ( 110 ) allows use of this equipment as a karaoke machine.
Two buffers ( 1101 , 1102 ) are connected to audio controller circuit ( 110 ) to allow storage of one item of information corresponding to a quarter of a second of sound each in alternation. Likewise, two buffers ( 1111 , 1112 ) are linked to video controller circuit ( 111 ) which are each able to store a tenth of a second of video alternately. Finally, a respective buffer ( 1041 , 1051 , 1071 ) is connected to each of the circuits of the communication controller ( 104 ), input interface ( 105 ) and extension ( 107 ).
The system operating software has been developed around a library of tools and services largely oriented to the audiovisual domain in a multimedia environment. This library advantageously includes an efficient multitask operating system which efficiently authorizes simultaneous execution of multiple fragments of code. This operating software thus allows concurrent execution, in an orderly mailer and avoiding any conflict, of operations performed on the display, audio reproduction structure as well as management of the telecommunications lines via the distribution network. In addition, the software has high flexibility.
The library contains, as will be shown below, a programming interface for buttons ( 102 ) or remote control ( 101 ) connected to each graphics module which will be described below, and linking to the functions of the connected graphics module functions of reaction to activation by one or more external events. External events originate from the user and are processed by the interface to be able to be interpreted by the operating system as the equivalent of a mouse event.
Digitized and compressed audiovisual data are stored in the nonvolatile storage of CPU ( 106 ) such as a static RAM.
Each selection is available according to digitized formats: with hi-fi quality or CD quality.
It must be noted that while all these modules described separately seem to be used sequentially, in reality the specific tasks of these modules are executed simultaneously in an environment using the multitask operating system.
The first module, labeled SSM, is the system startup module. This module does only one thing, consequently it is loaded automatically when the system is powered up. It then directly enters the “in service” mode of the module labeled RRM.
The RMM module is the module of the “in service” mode. In this mode the system is ready to handle any request which can be triggered by various predefined events such as:
the user who touches one of control keys ( 102 ) on front ( 10 ) or remote control ( 101 ). In this case the system transfers control of its foreground session to the CBSM module of the customer browsing and selection mode.
The system remains in this “in service mode” until one of the above described events occurs.
Thus, the RMM module of the in service mode includes a module allowing graphics display corresponding for example to that of FIG. 8 . The screen of this graphics module allows display of a window ( 90 ) which contains for example the display in zone ( 91 ) of the note “in progress” of execution. A second smaller window ( 92 ) included in first window ( 90 ) allows graphics display of the disk jacket during performance. In numeric keypad ( 93 ) the total time corresponding to pieces to be played which are stored in the queue is indicated. The number of songs in the queue is indicated in another digital keypad ( 94 ). A third smaller window ( 95 ) included in first window ( 90 ) displays a moving image such as a video clip, synthesized images or moving text if it is a karaoke title stored in the video files. In alphanumeric keypad ( 96 ) is the album title and in second alphanumeric keypad ( 97 ) the album name. In third alphanumeric keypad ( 98 ) the name of the artist or group is mentioned. This information originates from database ( 16 ) based on the title identification number and information stored in the database according to the access process explained below.
This reproduction screen displays the title which is performed, its total length ( 940 ), remaining time ( 930 ) and the disk jacket from which it originates. Use of the “action” function from the remote control or button ( 1025 ), cursor ( 950 ) being anywhere on the screen, allows the owner to pass to the screen of the selection shown in FIG. 10 .
In the case in which the jukebox is not playing a song and when the songs of the queue have been exhausted, one of two windows ( 92 , 95 ) will be able to be used to display promotional events or synthesized image animations.
A module specific to the remote control allows functions which command the system to accept an input requested by an infrared remote control device.
This remote control device can trigger display of the graphics screen located in FIG. 9 when the “purchase” key equivalent to ( 1019 ) of the remote control is pressed.
This remote control has keys with functions equivalent to those described above in FIG. 1, i.e.: ( 1026 ) to ( 1031 ), ( 1021 ) to ( 1025 ), ( 1019 ) to ( 1020 ).
The display of FIG. 9 allows the user to access the new selections acquisition mode in connection with the NSAM module.
This module shown in FIG. 9 contains a graphics module which allows display of window ( 1037 ). This window incorporates three subwindows ( 1032 , 1033 , 1034 ), the first ( 1032 ) in the form of a pull-down list makes it possible to have the selection list scrolled by pressing key ( 1025 ) by positioning a cursor ( 950 ) on pull-down arrow buttons ( 1060 , 1070 ). This selection list can only be displayed either after having displayed the category selection screen (FIG. 11 ), after having pressed button ( 1036 ) beforehand, highlighting title ( 1033 ) by positioning the cursor on the desired title and pressing key ( 1025 ), or after having introduced in subwindow ( 1039 ) at least one character by keyboard ( 1040 ) using the cursor and key ( 1025 ).
Generally the zones of graphics buttons are actuated by positioning cursor ( 95 ) using arrows ( 1021 to 1024 ) and pressing button ( 1025 ) or via the equivalent function keys of the remote control.
Window ( 1034 ) allows display:
when selection order button ( 1038 ) is activated, the note “type in your PIN”, in fact, purchase can only be possible if the personal identification number is accepted by central unit ( 1 ) of the playback system.
The user types his “PIN” on keyboard ( 1040 ); if the PIN is correct, window ( 1034 ) displays for example the note “credit card number” or if the purchase is billed on the telephone bill, window ( 1034 ) displays for example “purchase underway”.
A catalog of musical titles is kept in the primary module. This catalog can be updated at the request of the owner or automatically during purchase. The cost of each entry is displayed as well as the bill total by using information ( 1619 ) from the database (FIG. 7 ).
During communication it is possible for the server center to use it in order to upgrade the system operating software.
When the “detail” button ( 1035 ) is pushed, various information linked to the highlighted title appears in window ( 1034 ), such as the price of the selected title, its length, the album name, the name of the artist or any other information characteristic of the selected title.
Button ( 1038 ) allows ordering of the selection which is then downloaded according to the above described mode. Button ( 1035 ) allows display of the details on the selection. Third button ( 1036 ) allows selection of the category of music or the selection to be ordered. The user pressing this third button ( 1036 ) displays the screen shown in FIG. 11 which will be described below. Finally, the screen of FIG. 9 likewise contains an alphanumeric keypad representing keyboard ( 1040 ) which allows the user, by typing either the name of the album, artist or title written in subwindow ( 1039 ), to display in window ( 1032 ) a list of titles more or less restricted depending on the criterion used and the control keys allowing display of the preceding screen by arrow ( 1049 ) and the following screen by arrow ( 1050 ).
As stated above, the selection graphics screen shown in FIG. 10 is displayed by button ( 1025 ) from any zone of the playback graphics screen (FIG. 8 ). One example of the graphics module of the user browsing and selection mode module is shown in FIG. 10 in which window ( 120 ) includes three subwindows ( 121 , 1211 , 122 ), the first ( 121 ) being a pull-down subwindow. Pull-down of first window ( 121 ) is controlled by upper ( 126 ) and lower ( 127 ) pull-down arrows. As described above for the NSAM module, a title list can only appear in window ( 121 ) if a selection criterion has been introduced using keyboard ( 1201 ) connected to window ( 1211 ) of FIG. 10 or using window ( 110 ) triggered by category button ( 125 ) connected either to keyboard ( 1110 ) which can write an alphanumeric text in keypads ( 1120 , 1121 , 1130 , 1140 ), or to zones ( 1151 ) to ( 1156 ) of window ( 110 ) shown in FIG. 11 . Window ( 121 ) allows display of titles of selections in alphabetic order by song name. Window ( 122 ) allows display of the visual display unit corresponding to the song jacket. Button ( 125 ) allows selection of the song category and passage to the display of the following window shown in FIG. 11 . Button ( 124 ) allows validation of the selection or selections for initiating their introduction into the queue or their immediate and successive performance if the queue is empty. Window ( 120 ) is completed by alphanumeric keyboard ( 1201 ) which makes it possible to directly enter the name of another singer or song title. Pressing category button ( 125 ) of FIG. 10 equivalent to ( 1036 ) of FIG. 9 calls up a subroutine of the graphics module which triggers display of window ( 110 ) of FIG. 11 in which an alphanumeric keypad makes it possible to introduce using alphanumeric keyboard ( 1110 ), the album name in zone ( 1120 ), a second alphanumeric keypad ( 1121 ) makes it possible to introduce the name of the artist in zone ( 1121 ), and third and fourth alphanumeric keypads ( 1130 , 1140 ) allow introduction of a year or period and finally a line of buttons ( 1151 to 1156 ) allows selection respectively solely of “rock and roll”, “dance”, “country”, “rap”, “jazz” music albums or music for karaoke. Finally, window ( 110 ) contains button ( 1160 ) for cancellation in case of error, button ( 1170 ) for validation of the choice of selection, allowing return to window ( 120 ). Within subwindow ( 121 ) there then appears a list of one to several titles depending on a selection criterion, the user selects using cursor ( 950 ) the title which he wishes to hear, it is highlighted ( 1210 ) and simultaneously subwindow ( 122 ) displays the visual display unit corresponding to the album jacket containing the selected title. The user need simply press button ( 124 ) which causes changing of the graphics screen to display window ( 90 ) (FIG. 8) in which he will see appear in subwindow ( 92 ) the title jacket which he has selected and he will immediately hear it if the queue was at zero, in the opposite case he will see appear the title jacket will appear during performance and in keypad ( 94 ) the number of titles in the queue increased by the number of the titles which he has selected.
When the user presses button ( 1156 ) “karaoke”, in the graphics screen of the category illustrated in FIG. 11, then validates his choice by pressing graphics button ( 1170 ), the selection screen of FIG. 10 appears with a list of karaoke titles within the subwindow ( 121 ). By means of highlighting ( 1210 ) he chooses the title which he wishes to execute by then pressing button ( 124 ) which on the one hand causes display of reproduction screen ( 90 ) in FIG. 8 and on the other hand triggers reading of the pertinent title files which contain all the information necessary for operation in the karaoke mode described above.
The TSM module is the telecommunications services mode module between the central server and the audiovisual reproduction system. This module allows management of all management services available on the distribution network. All the tasks specific to telecommunications are managed like the background tasks of the system. These tasks always use only the processing time remaining once the system has completed all its foreground tasks. Thus, when the system is busy with one of its higher priority tasks, the telecommunications tasks automatically will try to reduce the limitations on system resources and recover all the microprocessor processing time left available.
A SPMM module allows the system to manage the musical song or video selections in the queue for their playback in the order of selection.
The multitask operating system comprises the essential component for allowing simultaneous execution of multiple code fragments and for managing priorities between the various tasks which arise.
This multitask operating system is organized as shown in FIG. 3 around a kernel comprising a module ( 17 ) for resolving priorities between tasks, a task scheduling module ( 18 ), a module ( 19 ) for serialization of hardware used, and a process communications module ( 20 ). Each of the modules communicates with application programming interfaces ( 21 ) and database ( 16 ). There are as many programming interfaces as there are applications. Thus, module ( 21 ) includes a first programming interface ( 211 ) for remote control ( 101 ), a second programming interface ( 212 ) for liquid crystal screen ( 12 ), a third programming interface ( 213 ) for audio control circuit ( 110 ), a fourth programming interface ( 214 ) for video control circuit ( 111 ), and a fifth interface ( 215 ) for telecommunications control circuit ( 104 ).
Five tasks with a decreasing order of priority are managed by the kernel of the operating system, the first ( 76 ) for the video inputs/outputs has the highest priority, the second ( 75 ) of level two relates to audio, the third ( 74 ) of level three to telecommunications, the fourth ( 73 ) of level four to interfaces and the fifth ( 70 ) of level five to management. These orders of priority will be considered by priority resolution module ( 17 ) as and when a task appears and disappears. Thus, as soon as a video task appears, the other tasks underway are suspended, priority is given to this task and all the system resources are assigned to the video task. At the output, video task ( 76 ) is designed to unload the video files from optional mass memory ( 108 ) alternately to one of two buffers ( 1111 , 1112 ), while the other buffer ( 1112 or 1111 ) is used by video controller circuit ( 111 ) to produce the display after data decompression. At the input, video task ( 76 ) is designed to transfer data received in telecommunications buffer ( 1041 ) to the static RAM of the CPU. It is the same for audio task ( 110 ) on the one hand at the input between telecommunications buffer ( 1041 ), and mass memory ( 108 ) and on the other hand at the output between mass memory ( 108 ) and one of two buffers ( 1101 , 1102 ) of audio controller circuit ( 110 ).
Task scheduling module ( 19 ) will now be described in conjunction with FIG. 4 . In the order of priority this module performs first test ( 761 ) to determine if the video task is active, i.e, if one of video buffers ( 1111 , 1112 ) is empty. In the case of a neoative response the task scheduling module passes to the following test which is second test ( 751 ) to determine if the audio task is active, i.e, if one of video buffers ( 1101 , 1102 ) is empty. In the case of a negative response, third test ( 741 ) determines if the communication task is active, i.e., if buffer ( 1041 ) is empty. After a positive response to one of the tests, task scheduling module ( 18 ) at stage ( 131 ) fills the memory access request queue and at stage ( 132 ) executes this request by reading or writing between the mass memory or CPU memory and the buffer corresponding to the active task, then loops back to the first test. When test ( 741 ) on communications activity is affirmative, scheduler ( 18 ) performs test ( 742 ) to determine if it is a matter of reading or writing data in the memory. If yes, the read or write request is placed in a queue at stage ( 131 ). In the opposite case, the scheduler determines at stage ( 743 ) if it is transmission or reception and in the case of transmission sends by stage ( 744 ) a block of data to the central server. In the case of reception the scheduler verifies at stage ( 746 ) that the kernel buffers are free for access and in the affirmative sends a message to the central server to accept reception of a data block at stage ( 747 ). After receiving a block, error control ( 748 ) of the cyclic redundancy check type (CRC) is executed. The block is rejected at stage ( 740 ) in case of error, or accepted in the opposite case at stage ( 749 ) by sending a corresponding message to the central server indicating that the block bearing a specific number is rejected or accepted, then loops back to the start tests. When there is no higher level task active, at stage ( 731 or 701 ) the scheduler processes interface or management tasks.
The kernel is occupied with rotation of the execution of tasks according to their priority and of communications between them. A task which manages video, one which manages audio, another which manages telecommunications and a last one which manages databanks are transferred to the kernel. Communications between the task and the kernel takes place by a common programming interface.
The number and type of active tasks is indicated to scheduler ( 18 ) by execution of selection management module SPMM whose flowchart is shown in FIG. 6 . The management exercised by this module begins with test ( 61 ) to determine if selections are in the queue.
Consequently, if test ( 61 ) on the queue determines that selections are waiting, when a user chooses a title he wishes to hear, it is automatically written in a queue file of a non-volatile memory of the system, such as the static battery backed-up RAM.
Thus, no selection made will ever be lost in case of an electrical failure. The system plays (reproduces) the selection in its entirety before removing it from the queue file.
When the selection has been reproduced in its entirety, it is removed from the queue file and the system checks if there are others in the queue file. If there is another, the system immediately starts to play the selection.
The total time transpired between the end of one selection and the start of the next is less than 0.5 seconds.
Processing is continued by test ( 65 ) to determine if the selection contains an audio scenario. If yes, at stage ( 651 ) this scenario is written in the queue of tasks of scheduler ( 18 ). If not, or after this entry, processing is continued by test ( 66 ) to determine if the selection contains moving images. If yes, the video scenario is written at stage ( 661 ) in the queue of tasks of scheduler ( 18 ). If no or if yes after this entry, processing is continued by test ( 64 ) to determine if the selection contains still graphics. If yes, at stage ( 641 ) this graphical presentation scenario is written in the queue of tasks of scheduler ( 18 ). If no or if yes after this entry, processing is continued by test ( 63 ) to determine if the selection contains a publicity scenario. If yes, at stage ( 631 ) the scenario is written in the queue of tasks of scheduler ( 18 ). Thus, scheduler ( 18 ) notified of uncompleted tasks can manage the progression of tasks simultaneously.
Due, on the one hand, to the task management mode assigning highest priority to the video task, on the other hand, to the presence of hardware or software buffers assigned to each of the tasks for temporary storage of data and the presence of status buffers relative to each task, it has been possible to have all these tasks managed by a single central unit with a multitask operating system which allows video display, i.e., moving images compared to a graphics representation in which the data to be processed are less complex.
Moreover, the multitask operating system which includes a library containing a set of tools and services greatly facilitates operation by virtue of its integration in the storage and the resulting high flexibility. In particular, for this reason it is possible to create a multimedia environment by simply and efficiently managing audio reproduction, video or graphics display and video animation. In addition, since the audiovisual data are digitized and stored in the storage, much less space is used than for a traditional audiovisual reproduction system and consequently the congestion of the system according to the invention is clearly less. Database ( 16 ) is composed, as shown in FIG. 7, of several bases.
A first ( 161 ) with the titles of the audiovisual pieces, second ( 162 ) with the artists, third ( 163 ) with the labels, fourth ( 164 ) with albums, fifth ( 165 ) with the words of karaoke selections. First base ( 161 ) contains first item ( 1611 ) giving the title of the piece, second item ( 1612 ) giving the identification of the product, this identification being unique. Third item ( 1613 ) makes it possible to recognize the category, i.e., jazz, classical, popular, etc. Fourth item ( 1614 ) indicates the date of updating. Fifth item ( 1615 ) indicates the length in seconds for playing the piece.
Sixth item ( 1616 ) is a link to the karaoke base. Seventh item ( 1617 ) is a link to the album. Eighth item ( 1618 ) is a link to the labels. Ninth item ( 1619 ) gives the purchase price for the user.
Tenth item ( 1610 ) is a link to the artist database. This link is composed of the identity of the artist. The artist database includes, besides the identity of the artist composed of item ( 1621 ), second item ( 1622 ) composed of the name of the artist or name of the group. The labels database includes first item ( 1631 ) composed of the identity of the label, establishing the link to eighth item ( 1618 ) of the title database, and second item ( 1632 ) composed of the name of the label. The album database contains a first item which is the identity of the album ( 1641 ) which constitutes the link to seventh item ( 1617 ) of the title base. Second item ( 1642 ) comprises the title, third item ( 1643 ) is composed of the date of updating of the album, and the fourth item ( 1644 ) is composed of the label identity. The karaoke base is composed of first item ( 1651 ) giving the identity of the title and corresponds to sixth item ( 1616 ) of the title base. Second item ( 1652 ) comprises for each title a file of each syllable and the time expired since the start of the song and at the end of which the singer must pronounce the syllable to have appear on the screen displaying the phases to be sung as a marker indicating the syllable at the instant determined by a timer. The timer is started at the time of karaoke use by the start of execution of the digital data of the music and counts up in rhythm with the processor clock which is likewise the time base for the music and the audio controller card.
It is easily understood that database ( 16 ) thus makes it possible to notify the user of the costs and particulars for each of the artists or groups of artists whose songs and videos are being performed, and to display the words necessary to the user of the apparatus in the karaoke mode.
Finally, in one of the two versions of the invention, a first recording module corresponding to the representation in FIG. 5A can be added to the primary system shown in FIG. 1 . This recording module is connected by extension connector ( 116 ) to primary module ( 1 ) and on the other hand by a socket to the electric grid. This module ( 109 ) is in fact a recording module which allows for example recording on a mini magnetooptical disk of one or more audiovisual pieces transferred to this medium via extension controller card ( 107 ) and extension connector ( 116 ) to device ( 109 ) which is able to operate with a SCSI/2 type bus. This thus makes it possible to consequently obtain mini magnetooptical disks ( 1090 ) on which the desired audiovisual pieces have been recorded for use on another player such as a car radio or any other equivalent device. In this example we have taken a mini magnetooptical disk unit, but this medium could be replaced very easily by digital tape recording allowing no loss of audio quality of the data recorded and operation on the marketed components of a stereo system or car radio.
Finally, the user can add to his central component ( 1 ) another module ( 108 ) which is composed of an external storage unit which can be comprised of a hard disk system or any other equivalent system allowing the user to store several audiovisual pieces, whereas primary system ( 1 ) can only store in its non-volatile memory a limited number of pieces; this number is limited by the size of the battery backed-up static RAM which participates equally in operation of primary unit ( 1 ).
Operation is as follows:
a) listening
The user begins by connecting the jukebox to his stereo system and his TV set, then turns them on.
If he wants to hear or view a video, he presses the “action” function of the remote control to obtain the selection screen. Using the search options he makes his choice and begins playback. The new choice is queued if there is already an active piece.
A liquid crystal screen on the apparatus allows sequential access to a list in alphabetical order. A “play” button ( 1028 ) starts playback.
With the remote control or control buttons ( 1026 to 1031 ) the user can pause, stop, read, rewind, fast forward, or skip to the following title.
He can ask the system to play all the pieces in sequence or randomly.
b) at purchase
From the selection screen the acquisition screen is accessed. To purchase a title, the system demands the personal identification number (PIN). PIN use protects parents against wrongful billing which their children may cause. In this screen the user can purchase one or more musical pieces which have been offered to him based on a list which is resident in the apparatus and which is updated during communication with the distribution server center. Search on this list takes place by title, artist, category, alphabetical order and by release date. The cost of each piece is displayed as well as the total bill. Then he indicates to the system that he has finished making choices. The system then checks if there is enough memory to accommodate all the requested pieces. If there is a problem, the system advises the customer thereof, otherwise it requests the credit card number of the customer or displays it if it is already in the memory. Then the system attempts to reconnect to the server center to complete the transaction either by phone line or satellite link or by dedicated line. Since the system is a multitask system, it can even play the audiovisual pieces during transfer.
c) by its telecommunications card each apparatus can be connected to a server center. This possibility allows a flexibility which cannot be equalled by other, similar apparatus. It allows:
remote repair for minor problems,
assistance to a technician in locating the defective part or parts,
purchase of musical pieces without having to leave home,
choosing only musical pieces of interest to us,
access to an impressive list of musical pieces which are not always available at the record shop,
updating or modification of the software.
When a software update is received, this new version will be used the next time the system is used.
It is also possible to include advertising on the screens. This advertising can be changed each time the system is connected to the server center.
Audio and video will be digitized using commercial software which uses standard file formats.
Digital audio and video data will be kept according to a standard compressed format. They will be decompressed during reproduction. The purpose of this is to minimize use of memory space and shorten the time of transfer to the server center.
The server center, since it is a computer, validates the credit card and bills the customer automatically without manual intervention and can answer several calls at the same time.
Any modification by one skilled in the art is likewise part of the invention. Thus, regarding buffers, it should be remembered that they can be present either physically in the circuit to which they are assigned or implemented by software by reserving storage space.
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A digital home audiovisual information recording and playback apparatus includes a microprocessor associated, through a digital interface, with a display, through another interface with sound playback structure and through a telecommunications interface with structure for loading audio selection or visual selection digital information. The system includes structure for controlling the display, enabling an operating mode to be selected from a menu of three modes, in which the device either plays back information stored in its mass memory, records new digitized information in its mass memory or combines analog information from a microphone with digitized information received from the mass memory.
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This application is a continuation of application Ser. No. 528,482, filed Nov. 29, 1974 for Shutter and Awning Device, which in turn was a continuation of application Ser. No. 313,563, filed Dec. 13, 1972 now both abandoned.
SUMMARY OF THE INVENTION
The present invention is a security type shutter device which, though containing rigid members, can be rolled up on a roller. The device includes slats made from aluminum or other extrudable material of sufficient strength to protect the window or other access opening against damage from storms or vandalism. Each of the slats is of uniform cross-section whereby they can be made on a common extruding die and shaped so that they may be assembled by sliding one within another. The unique awning and shutter device of the present invention is slidably mounted within a pivotable framework whereby when the awning or shutter device is moved toward its lowered position it may be pivoted outwardly from the wall so as to act as an awning. Conveniently, the individual slats have a concave shape facing outwardly from the wall to add to the strength of the individual slats and further to prevent reflections from the sun which would be objectionable to people in the area of the protective device. In addition, the present device provides a means for conveniently raising and lowering the shutter or awning comprised of a rotary gear mechanism which may be manually operated.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the shutter and awning device of the present invention with the device mounted over a window in its lowered position;
FIG. 2 is a schematic view as in FIG. 1 with the shutter and awning device in its pivoted or awning position;
FIG. 3 is a schematic view of the shutter and awning device in its retracted position;
FIG. 4 is a schematic view of the shutter and awning device as modified for use with a door;
FIG. 5 is a rear elevation view of the awning and shutter device of the present invention;
FIG. 6 is a sectional view taken along line 6--6 of FIG. 5;
FIG. 7 is a sectional view taken along line 7--7 of FIG. 5;
FIG. 8 is a sectional view taken along line 8--8 of FIG. 5;
FIG. 9 is a view similar to FIG. 8 with the device shown in its pivoted or awning position;
FIG. 10 is a perspective exploded view of some of the frame members and other parts of the shutter and awning device of the present invention; and
FIG. 11 is a perspective exploded view of the pivot mechanism for the awning device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the shutter and awning device 10 of the present invention is shown in schematic view and includes a rotary drive mechanism 12 operable by a preferably removably driving handle 13, frame mechanism 14 and a shutter mechanism 16. In FIG. 1, the device is shown with the awning or shutter in its lowered position with the slats engaged within the frame mechanism 14 and in a lowered position.
Referring to FIG. 2, a perspective view of the device 10 is again presented with the awning or shutter 16 in its pivoted or awning position. FIG. 3 is a similar schematic view in which the rotary drive mechanism 12 has been actuated to retract the shutter to provide access to the window 18.
Referring to FIG. 4, the device 10 is shown as adapted to act as a retractable protective shutter for a door. In this embodiment, no pivot mechanism is provided since the awning function of the device 10 is not desired.
Referring to FIGS. 5, 6 and 7 the drive mechanism 12 for the shutter and awning device 10 includes a rotary shaft 20 having a bevel gear 21 at the right end thereof located in a gear box 22 secured to the wall 23 in which the window 18 is provided. An additional gear box 24 is mounted on wall 23 beneath box 22. A shaft 25 contained within a tube 26 extends between the gear box 24 and gear box 22 and has a bevel gear 28 on the upper end thereof meshing with bevel gear 21 on the shaft 20 and bevel gear 30 on the lower end thereof within gear box 24. Rotatably mounted in gear box 24 is a driving shaft 32 having a bevel gear 34 mounted thereon in meshing engagement with the bevel gear 30 on the lower end of shaft 25. By means of the driving mechanism 12 the awning or shutter device 16 may be rolled upon the shaft 20 to raise the awning or shutter by manual rotation of shaft 32. A lock mechanism 35 is provided including a cap member 36 secured to gear box 24 with a spring 37 therebetween. Mating locking teeth 38 are provided inside cap member 36 and on a shoulder portion 33 of shaft 32. Spring 37 urges the mating teeth into engagement to hold shaft 32 against rotation except when the driving handle 13 FIG. 1, (not illustrated) at FIG. 7 is pressed in a socket 39 in the end of the shaft 32 to displace the shaft 32 longitudinally against the pressure of the spring 37 to disengage teeth 38 and thus permit rotation of shaft 32 by the driving handle, the shaft 32 being longitudinally displaceable of a distance permitting the engagement of the teeth 38 and supporting bevel gear 34 by any convenient sliding means such as a spine and groove coupling, not shown.
Referring to FIGS. 5 and 10, the shutter mechanism 16 comprises a series of individual slats 40 of identical cross-section forming an articulated curtain. The slats 40 are shaped concavely in a direction outwardly from the wall 23 and are conveniently formed from an extrudable metal or other material such that individual slats may be economically manufactured. Each slat 40 has a socket portion 42 extending along one edge thereof and a rod portion 43 extending along the other edge thereof whereby individual slats can be assembled together by sliding the rod portion 43 of one slat into the socket portion 42 of the next to form a coupling between the slats. In this manner, the slats may pivot with respect to one another and are in a force transmitting relationship.
The bottom slat or rail 46 of the shutter mechanism 16 has a large bar 48 at the bottom thereof extending the length of the slat 46 which imparts strength to the mechanism when in its lowered position. Slat or rail 46 provides additional security against vandalism and storm damage and aids by virtue of its weight in the sliding movement of shutter mechanism 16 in frame mechanism 14. The edges of the slat or rail 46 are formed with T-shaped sections 49 (See FIG. 7) which are received within a groove in frame mechanism 14 on either side of the shutter 16.
The shaft 20 for retracting the shutter mechanism 16 has a series of splines 50 (See FIG. 10) formed thereon. A collar 52 having a bore 54 of complementary shape to that of splines 50 on the shaft 20 is assembled over the shaft 20 on either end thereof. Formed with the collar 52 is a driving lug having a lower portion 58 and an upper portion 60. The upper portion 60 is adapted to be received by rod 43 of the uppermost slat 40 whereby when the shaft 50 is rotated the first slat 40 will be moved about the axis of shaft 20 and due to the force transmitting relationship will pull up the other slats 40 to retract the shutter mechanism 16 and roll the shutter upon the shaft 20.
The frame mechanism 14 includes a side frame member 61 on either side of the device 10. Each of the side frame members 61 is made of an extrudable material such as aluminum or plastic and has a vertical slot or groove 62 formed on the inner edge thereof which is adapted to receive an end portion of bottom slat or rail 46 and forms a track for slats 40 to enable them to travel vertically. Also provided on the side frame members 61 is a groove 64. In addition, the frame mechanism 14 includes lower frame members 66 on either side thereof which are adapted to be secured to the wall 23. The members 66 have a slot or groove 68, FIG. 7 which is identical to slot 62 of the side frame members 61. Bottom slat or rail 46 is milled to be captured in but to be able to slide up and down within grooves 62 and 68. As shown in FIG. 11 a pair of felt strips 69 are provided on either side of the grooves 62 and 68 to provide a snug fit for the ends of the bottom slat or rail 46 to prevent rattle and noisy operation when the shutter device is raised or lowered.
Also provided in the lower frame members 66 is a groove or slot 70 which is complementary to the slot 64. Provided on the upper end of the frame member 61 is a pivoting mechanism 72 which permits pivotal movement of the side frame members 61 when the shutter mechanism 16 is in its partly lowered position as illustrated in FIG. 2 to act as an awning. A pair of guide arms 80 are provided on either side of the device 10 which have guide members 82 and 84, best shown at FIG. 10, secured thereto on the upper and lower ends respectively thereof. The guide member 84 is secured within the groove 70 in the lower frame member 66 by a screw 85 such that it will not slide with respect thereto. The upper guide member 82 is secured to the guide arm 80 by a screw 86 and is slidably received within the groove 64 in the side frame member 61 whereby when the awning or shutter mechanism 16 is pivoted outwardly as shown in FIG. 2 to act as an awning the guide arms 80 will pivot outwardly with the guide member 82 sliding within the slot or groove 64 and the lower end of the guide arm 80 pivoting about the fixed guide member 84. In this way the guide arms 80 act as supports for the shutter mechanism 16 when it is in its pivoted or awing position illustrated in FIG. 2.
Pivot mechanism 72 includes a stationary support member 90 and a pivot member 92. Support 90 is secured to wall 23 by screws 93 and has an upper groove 94 adapted to receive a lower portion 95 of gear box 22. Support 90 also includes a hollow portion 96 having a socket shaped threaded portion 97. Pivot member 92 has an arcuate portion 100 adapted to contact slats 40 when member 92 pivots and a mounting portion 102 having bores 103 and 104 therein. As best illustrated in FIG. 10 a threaded shoulder bolt 106 extends through bore 104 and into threaded socket portion 97 of support 90 thereby pivotally mounting pivot member 92 on support 90. Referring to FIG. 11 the frame members 61 are carried by pivot member 92 so that the frame members 61 may be pivoted. A block 110 is received in groove 64 and has a threaded bore 111 therein. A screw 112 extends through bore 103 and is received within bore 111 thereby securing pivot member 92 to frame member 61.
Also shown in FIG. 10 is a lock member 114 which may be received within a slot 116 of lower frame member 66. A matching slot 118 is provided in frame member 61 and when the frame member 61 is in its non-pivoted position and the lock 114 is slid to a position in engagement with both slots 116 and 118, the side frame members 61 are secured in their non-pivoted positions.
A latch mechanism 120 (See FIGS. 5 and 10) is provided and mounted within bar 48 which includes a pair of spring loaded latch members 122 having a groove 124 therein. Since the members 122 are spring loaded apart, when the shutter and awning is lowered to its lowered position as illustrated in FIG. 5, the members 122 will move apart and grooves 124 will engage the lower end of frame member 66 to hold the shutter and awning device in its lowered position. Finger cut-outs 126 are provided in each latch member 122 so that they can be retracted to enable raising or retracting of the device.
Referring to FIG. 7 an optional construction of shaft 32 is illustrated in phantom lines wherein the shaft 32 extends through wall 23 so that for security purposes the device 10 may be raised or lowered from inside the building.
From the above, it will be apparent that the present invention provides an economical combined shutter and awning device which will afford maximum security against storms and/or vandalism and at the same time provides the advantage of being usable as an awning in a pivoted position outwardly from the window. In addition, the individual slats 40 of the shutter mechanism 16 are of common cross-section such that they can be manufactured by extruding process through a common extruding die and the shape thereof affording a force transmitting relationship between each of the slats along the entire length thereof such that the force transmitting relationship is sufficiently strong to withstand damage and at the same time to afford the force transmitting relationship necessary when the shutter mechanism 16 is moved to its retracted position illustrated in FIG. 3.
Various features of the invention have been particularly shown and described, however, it should be obvious to one skilled in the art that various modifications may be made therein without departing from the scope of the invention.
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A combined shutter and awning protective device for an opening in a wall such as a window, comprising a plurality of slats of uniform cross-section slidably received within one another and having a rotary member by means of which the shutter can be rolled upon the rotary member to provide for raising and lowering thereof. The device includes frame members which are pivotable whereby the device can be pivoted outwardly from a wall or the like to act as an awning. The device also includes frame sections secured to the wall which allows the device, in its non-pivoted position with the shutter fully lowered, to secure itself in position over the window or the like to act as a protective and security covering.
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BACKGROUND
This invention relates to isolation transformers and isolation transformer assemblies.
An isolation transformer is a transformer designed to provide magnetic or flux coupling between one or more pairs of isolated circuits, without introducing significant coupling of low frequency signals between them, such as either significant conductive or electrostatic coupling. Isolation transformers are typically used in power supplies of consumer electronic goods, such as personal computer systems, to isolate the user from the high voltage and current levels of AC power as required by regulatory agencies. When the isolation transformer is to be used in an application such as consumer electronics, where space is at a premium, it is important to have the transformer only occupy a minimum volume of space. In addition, the transformer must provide isolation between the circuits.
In order to achieve the desired isolation between primary and secondary circuits, the conventional construction of isolation transformers typically requires significant air gaps, creepage, and clearances to avoid conductive or capacitive coupling. Referring to FIGS. 1-2, one such conventional construction is a plastic bobbin 20, which includes a hollow cylindrical spindle 22 having a central hole 26 and two end rims 24 on either side of the spindle 22. The bobbin 20 is used in a conventional isolation transformer 28 as shown in FIG. 2. A length of Mylar tape having a width of about 2.5 mm is wound about the spindle 22 adjacent each end rim 24 to form a layer of tape 32 having the approximate height of the wire used for a primary winding 30. Next, magnetic wire is wound about the spindle 22 on its central portion between the layered tape side by side in a manner known to those skilled in the art to form the primary winding 30. Then, two layers of Mylar tape are wound on top of the primary winding 30 and the layered tape 32 to form a tape isolation layer 34 between the primary winding 30 and a secondary winding 38. Then, two other tape layers 36 having a width of about 2.5 mm are wound adjacent the end rims 24 on top of the tape isolation layer 34. Finally, magnetic wire is wound on top of the tape isolation layer 34 to form the secondary winding 38. A magnetic core 42 is inserted into the central hole 26 of the hollow spindle 22 to complete the isolation transformer of the prior art. The magnetic core 42 is mounted to provide a tolerance air space 40 between the core 42 and the windings 30 and 38 to allow for ease of assembly. The tape layers 32 and 36 are necessary to provide the appropriate clearance between the primary and secondary windings 30, 38 to account for creepage. In addition, wire sleeving or insulated sleeving must be installed on terminal leads of the primary and secondary windings, and further spacing may be required for conductive cores and other compounds.
Another conventional isolation transformer utilizes a two piece plastic bobbin to eliminate the labor involved with the wrapping of tape around the respective coils. Referring to FIG. 3, a conventional isolation transformer 50 using a two piece plastic bobbin is shown. A primary bobbin 56 includes a cylindrical primary spindle 64 with primary rims 66 mounted on either end. Magnetic wire is wound on the spindle 64 to form the primary winding 58. A secondary bobbin 60 includes a secondary spindle 68 and two secondary end rims 70 on either end. Again, magnetic wire is wound around the secondary spindle 68 to form the secondary winding 62. The secondary bobbin 60 also includes an extension tab 72 and flange lips 74 extending inward on one end of the secondary bobbin and forming a gap 76 between the flange lips 74 and the primary bobbin 56. The flange 76 is an appropriate size to receive the primary bobbin 56 so that the primary bobbin 56 fits within the secondary bobbin 60. Core material 52 has a cylindrical gap 54 in which the primary and secondary bobbins 56, 60 are placed with the gap 54 about a central area of the core material 52.
Planar magnetics have been developed to reduce the overall size and height of electronic devices such as isolation transformers. Referring to FIG. 4, a conventional isolation transformer 78 using planar magnetics for ease of assembly is shown. Two E-shaped ferrite core halves 80 each preferably comprises a relatively flat magnetic plate 81 with an inner rail or bar 84 and two outer bars 82 formed on either end of the plate 81. Two ferrite core halves 80 are aligned to face each other and to sandwich a plurality of windings, wherein the windings are fabricated using planar magnetics. In a first form of planar magnetics, primary windings 96 are etched or otherwise routed on a PCB board comprising an insulation material such as FR4, Mylar, or Kapton to form a primary board 90. The primary board 90 includes a central hole 102 to receive the inner bar 84 of the ferrite core halves 80. Likewise, a secondary winding 98 is etched on a secondary board 92 having a central hole 102 in a similar manner as the primary board 90. Other windings could be included, such as auxiliary winding 100 etched on an auxiliary board 94 as shown. The primary, secondary and auxiliary boards 90, 92 and 94 are joined or otherwise mounted together and sandwiched between the ferrite core halves 80 to form the isolation transformer 78 of prior art.
Referring to FIG. 5, an alternative form of planar magnetics is shown comprising a flex circuit 110 generally having an S-shape prior to folding. The flex circuit 110 includes etched traces 112 routed on the flex circuit 110, wherein the traces 112 eventually form the windings of the transformer. The flex circuit 110 comprises a mid-section 114 and an end section 116 and another end section 118 both separated from the mid-section 114 by fold lines 120 and 122, respectively. In assembly, a fold is made along line 120 so that the end section 116 is folded on top of the mid section 114, and then a fold is made at the line 122 so that the end section 118 is folded on top of the mid-section 114. Two or more sets of independent traces 112 are etched on the flex circuit 110 to form the primary, secondary and auxiliary windings, if desired. The folded flex circuit 110 is placed between the ferrite core halves 80 shown in FIG. 4.
SUMMARY OF THE INVENTION
In general, in one aspect, the invention features an isolation transformer having two core pieces mounted to cooperate to provide flux paths, one of the core pieces being shaped to define the central flux path, and one or more magnetically coupled windings surrounding the central flux path, and an isolation layer sandwiched between the two windings.
Implementations of this aspect of the invention may include the following features. The isolation layer may include adhesive on one side or on both sides. The isolation layer may comprise a piece of transfer adhesive tape. The isolation layer may include two pieces of insulating tape adhered together and adhered to a core piece on an exposed side of one of the pieces of tape. The windings may be free standing bondable windings. A third winding may surround the central flux path. A fourth winding may surround the central flux path. Both of the core pieces may be e-shaped.
In general, in another aspect, the invention features a primary winding mounted on a first core, a secondary winding mounted on a second core, an isolation tape layer sandwiched between and separating the primary and secondary windings and the two cores, and a support having a bottom surface and opposite side walls housing the coils and the cores.
Implementations of this aspect of the invention may include the following features. The support may include primary terminals and secondary terminals on opposite side walls. Primary leads may extend from the primary winding to the primary terminals, and secondary leads may extend from the secondary winding to the secondary terminals. One of the side walls may include wire channels for receiving leads extending from either of the windings. Insulating tape may be used to hold together the cores, windings, and support. The tape may be adjacent to the primary and secondary cores and wrap around the support.
In general, in another aspect, the invention features an insertion tool for receiving the isolation transformer, the tool having a channel along which the isolation transformer passes during insertion, the channel including a side wall, flanges flaring outward from an end of the channel to guide the isolation transformer into the channel and to fold the insulating tape, and the side wall having wire channels extending along the length of the wall.
Implementations of this aspect of the invention include the following features. The wire channels may be aligned with the wire channels of a support of the isolation transformer. The flanges may fold an isolation tape layer of the isolation transformer as the isolation transformer is fed into the channel. The wire channels may receive the wires of a winding of the isolation transformer.
In general, in another aspect, the invention features a method of assembling an isolation transformer by inserting an isolation transformer into an insertion tool at an upper end of the insertion tool and passing the isolation transformer along the insertion tool, and receiving the transformer in a transformer support adjacent the lower end of the insertion tool.
Implementations of this aspect of the invention include the following features. This aspect of the invention may feature a method of assembling an isolation transformer by folding an isolation tape layer of the transformer. This aspect of the invention may feature a method of assembling an isolation transformer by guiding the wires of a winding of the transformer as it passes along the length of the insertion tool. This aspect of the invention may feature a method of assembling an isolation transformer by folding a tape layer around the transformer and the support.
In general, in another aspect, the invention features an automated method of assembling an isolation transformer assembly by receiving a secondary winding coil and secondary core half, adhering an isolation tape layer on the secondary winding coil and secondary core half, receiving a primary winding coil and primary core half, adhering the primary winding coil and primary core half to the isolation tape layer to form an isolation transformer, placing the transformer into an insertion tool, and securing the transformer into a support to form the assembly.
In general, in another aspect, the invention features an automated isolation transformer assembly tool having a slot for holding the core halves of an isolation transformer, first and second knobs for securing the winding coils of an isolation transformer, and an isolation tape layer dispenser.
Implementations of this aspect of the invention include the following features. This aspect of the invention may feature an arm for lifting the transformer from the slot for insertion into a carrier. The assembly tool may comprise a carousel with multiple workstations. The carousel may be pivoted sideways.
Advantages of the invention may include one or more of the following. The isolation transformer is volume efficient, cost efficient, and easy and time efficient to manufacture. An isolation layer may be used to keep the windings in place and provide the required isolation barrier, eliminating the need for margin tape, tolerance airspace and large creepage clearances. The isolation layer provides full isolation between the primary and secondary windings and also serves to conveniently hold the core halves together. The isolation transformer is manufactured in a manner to reduce the space that the transformer occupies in power supplies.
An insertion tool is useful for placing an isolation transformer into a support. An insertion tool easily guides the windings of a transformer so that they may be connected to the terminals on a support. An insertion tool easily and precisely folds the isolation tape layer of the isolation transformer upwards.
An automated method of manufacturing an isolation transformer is useful for increasing the efficiency of producing the transformers.
Other advantages and features will become apparent from the following description and from the claims.
DESCRIPTION
FIG. 1 is a perspective view of a plastic bobbin used in a conventional isolation transformer;
FIG. 2 is a cross-sectional side view of the upper half of a conventional transformer using the plastic bobbin in FIG. 1;
FIG. 3 is a cross-sectional side view of a conventional isolation transformer using a two piece plastic bobbin;
FIG. 4 is an exploded front view of a conventional transformer incorporating planar magnetics;
FIG. 5 is a side view of conventional transformer windings using flex circuit with traces;
FIG. 6 is an exploded side view of an isolation transformer;
FIG. 7 is a top view of a bondable free standing winding used in the transformer assembly of FIG. 6;
FIG. 8 is an exploded side view of an isolation tape layer for use in a transformer;
FIGS. 9A, 9B and 9C are perspective and first and second side views of a transformer assembly;
FIG. 10A is an exploded perspective view of an isolation transformer;
FIG. 10B is a perspective view of a core half for use in the isolation transformer of FIG. 10A;
FIG. 10C is an exploded cross-sectional view of the isolation transformer of FIG. 10A;
FIG. 10D is a cross-sectional view of the isolation transformer of FIGS. 10A and 10C;
FIGS. 11A and 11B are opposing side views of an insertion tool for inserting a transformer into a carrier;
FIG. 11C is a perspective view of the insertion tool;
FIG. 11D is a top view of a bracket used on the insertion tool; and
FIGS. 12A-12E are side views of an automatic assembly tool for assembling a transformer assembly.
In the isolation transformer 186 of FIG. 6, two opposing E-shaped ferrite core halves 130 and 131 sandwich primary winding coils 140, 142, an isolation tape layer 148 and secondary winding coils 144, 146. The ferrite core halves 130, 131 are significantly smaller than the E-shaped core halves 80 used in a conventional transformer as shown in FIG. 4. The core halves 130, 131 may be C-shaped, pot-core shaped, PQ-core shaped or of any other magnetic shape. The primary and secondary ferrite core halves 130 and 131 include a flat magnetic plate 133 on one side, two outer walls 132 and a center wall 134, forming two gaps 136 on the opposite side between center wall 134 and the two outer walls 132. Walls 132, 134 and 136 are parallel to each other and approximately the same height. The planar topology of the isolation transformer 186 does not require bobbins or margin tape, thus allowing for a compact assembly.
The primary winding coils 140, 142 fit within the gaps 136 of the primary ferrite core half 130. The coils 140, 142 fit with a tight tolerance. An isolation tape layer 148 is then placed across the outer and center walls 132, 134 of the primary ferrite core half 130 to hold the coils 140, 142 in place. Similarly, the secondary winding coils 144, 146 are aligned with the center wall 134 of the secondary ferrite core half 131, and the primary and secondary cores 130, 131 are placed together so that the ends of the outer and center walls 132, 134 contact the isolation tape layer 148. The isolation tape layer 148 includes adhesive on both sides to hold the respective core halves 130, 131 together before final assembly. The isolation tape layer 148 is longer than the length of the core halves to account for required creepage. The isolation tape layer 148 provides appropriate isolation between the primary and secondary core halves 130, 131. Although the number of primary and secondary coils may vary depending on the isolation transformer configuration, an isolation transformer includes at least one primary winding coil and one secondary winding coil.
Referring also to FIG. 7, the winding coils 140, 142, 144, 146 are elliptical, forming a hole 154, and are configured to be tightly held within their respective E-shaped core halves 130, 131. The winding coils 140, 142, 144, 146 are shaped to closely fit center wall 134, and their shape may vary with the shape of core halves 130, 131. The cross-sectional area of the center wall 134 of the isolation transformer 186 may be increased, thereby reducing the number of turns in winding coils 140, 142, 144 and 146. The winding coils 140, 142, 144, 146 are formed from bondable magnetic wire which is wound in a single layer to form a bonded free standing winding. The coil 140 does not flex easily but is a free standing winding due to the bonding material placed on the wire for ease of assembly of the transformer. The ends 150, 152 of the wire forming the coil 140 are separated from the coil 140 for access to external circuitry. In this manner, a worker may readily handle the coils 140, 142, 144 and 146 for ease of placement and manufacture of an isolation transformer.
Referring to FIG. 8, the isolation tape layer 148 includes two pieces of standard electrical tape 162, 164 and one layer of transfer adhesive 160. Electrical tape 162 is sandwiched between transfer adhesive 160 and electrical tape 164. Each layer of tape 160, 162, 164 includes adhesive on its bottom surface. The transfer adhesive 160 has a layer of release paper 166 along its top surface instead of Mylar tape. When the 3 layers 160, 162 and 164 are properly aligned and adhered together, the release paper is removed, leaving an adhesive layer 168 along the top surface of tape layer 160. As a result, the isolation tape layer 148, which is comprised of two layers of tape in thickness also includes adhesive on its top and bottom surfaces. The isolation tape layer 148 is made to meet agency and safety requirements. Because the isolation tape layer 148 is comprised of more than a single layer of tape, according to federal agency standards, each layer of tape must provide 3000 volts of isolation within a specified creepage distance between the primary and secondary windings. The thickness of the resultant isolation tape layer 148 is in the range of 2.5 to 4 mils thick. The isolation tape layer 148 may be substituted with another isolation barrier sandwiched between the two core halves 130, 131.
Referring to FIGS. 9A, 9B and 9C, the transformer 186 is placed within a carrier 170. The carrier 170 is a rectangular plastic box and is sized according to the size of the transformer 186. The carrier includes a bottom surface 181 and four side walls 172, 173, 174, 175 substantially perpendicular to each other and the bottom surface 181. First opposing sides walls 173 and 175 include smooth surfaces and are formed to be adjacent the outer walls 132 of the transformer 186. Second opposing side walls 172, 174 are adjacent the primary and secondary windings, respectively. Side wall 172, which is on the secondary wire side of the carrier 170 includes wire channels 178. The wire channels 178 are tapered outward along the periphery of the carrier 170. Side wall 174, which is on the primary wire side of the carrier 170, is a smooth surface. Side walls 172 and 174 include surface mount pins 180 along the bottom of the walls 172 and 174. The pins 180 of the secondary wire side are aligned with the individual wire channels 178.
The transformer 186 is inserted into the carrier so that the bottom surface of secondary core half 131 is adjacent the bottom surface 181 of the carrier 170 and the top surface of the primary core half 130 is approximately level with the top of the side walls 172, 173, 174 and 175 of the carrier 170. The wires 182 of secondary windings 144 and 146 are inserted in their respective wire channels 178 so that they contact their respective surface mount pins 180. The wires 184 of primary windings 140 and 142 are placed over opposing wall 172 of the plastic carrier 170 so that they contact their respective surface mount pins 180. Then the wires 182 and 184 may be soldered to the pins 180.
As shown in FIG. 9B, the transformer assembly may further include a piece of tape 188 for final assembly. The tape 188 is placed across the plastic carrier 170 prior to insertion of the transformer 186 so that the tape 188 may be wrapped around the transformer 186 and plastic carrier 170. Once the transformer 186 is secured within the carrier 170, first end 190 of the tape 188 is folded across the top of the transformer 186. The opposing end 192 of the tape 188, which is longer than the end 190 is wrapped across the top of the transformer 186 and around the plastic carrier 170 to secure the assembly.
Other types of isolation layers instead of isolation tape layer 148 may be used. For example, referring to FIGS. 10A-10D, an isolation transformer 300 includes ferrite core halves 302 and 304, carrier 306 having an isolation layer 308, and winding coils 310 and 312. Core halves 302 and 304 are rectangular in shape and include a flat magnetic plate 314 on one side, outer walls 316, 318, 320 and 322, and center wall 324. The outer walls 316, 318, 320 and 322 and center wall 324 form a central gap 326 for receiving a winding coil 310 or 312. Wall 322 includes a recess 328 for receiving the distal ends 330 of the winding coils 310 and 312. Winding coils 310 and 312 fit with a tight tolerance within the central gap 326 of core halves 302 and 304, respectively. The coils 310 and 312 are positioned so that the distal ends 330 of the coils 310 and 312 fit through recess 328. Central wall 324 may be circular in shape depending on the shape of winding coils 310 or 312.
Primary winding coil 310 fits within primary core half 302. Secondary winding coil 312 fits within secondary core half 304. Carrier 306 includes a primary compartment 336 and a secondary compartment 338 which are separated by isolation layer 308. Isolation layer 308 forms the bottom surface of primary compartment 336 and the top surface of secondary compartment 338. Each core half 302 and 304 slides into a compartment 332 or 334 of carrier 306. Each compartment 336 and 338 is formed to securely hold the primary and secondary core halves 302 and 304, respectively. Each compartment 336 and 338 includes an outer surface 340 which is approximately parallel to isolation layer 308. Each compartment 336 and 338 also includes three side walls 342, 344 and 346, which along with the outer surface 340 and isolation layer 308 form compartments 336 and 338. The outer surface 340 is bowed toward isolation layer 308 to secure the core halves 302 and 304 in place within carrier 306.
Referring to FIGS. 11A-11D, an insertion tool 200 may be used for facilitating the insertion of the transformer 186 into the plastic carrier 170. The insertion tool 200 is funnel-like in shape and includes an upper portion and a lower portion. The upper portion includes flanges 202 which flare outward on opposing sides of the upper portion. The flanges 202 form an opening 203 into which the transformer 186 is inserted. The lower portion forms a channel 205, which is formed by a pair of opposing walls 201 and 206. First opposing walls 201 extend downward from flanges 202. Second opposing walls 206 are perpendicular to walls 201. Walls 206 are formed to align with the primary and secondary side walls 172 and 174 of the carrier 170. One of secondary walls 206 includes vertical slots 204, which are spaced so that they may align with wire channels 178 of the plastic carrier 170. The vertical slots 204 are formed by wall portions 207, which are supported by brackets 208. Wall portions 207 extend along the length of the secondary wall 206. Brackets 208 include fasteners 209 for securing the brackets to insertion tool 200. The brackets 208 are U-shaped with the legs 192 of the U attached to first opposing walls 201. Each bracket 208 includes supports 194 which are adhered to wall portions 207. The supports 194 are approximately parallel to the legs 192 of the bracket 208. First opposing walls 201 are angled outward in a trapezoidal manner such that the distance across the bottom of the lower portion is approximately the length of the carrier and the distance across the top of the lower portion is about equal to the distance across the flanges 202 of the top portion. The lower portion of the insertion tool 200 is box-like and is sized to fit the carrier 170.
To use the insertion tool, the transformer 186 is inserted within the channel 205 of the insertion tool 200 and the wires 182 of secondary windings 144 and 146 are aligned with the corresponding slots 204 for insertion into the plastic carrier 170. Flanges 202 are angled to fold the edges of tape layer 148 extending from the outer walls 132 of the transformer 186 upwards. Walls 206 of the lower portion fold the edges of tape layer 148 extending along the length of transformer 186 upwards. Tape 188 may be placed between the plastic carrier 170 and the insertion tool 200 so that once the transformer 186 is inserted into the plastic carrier 170, tape 188 is folded upwards as shown in FIG. 9B.
Referring to FIGS. 12A-12E, an automatic assembly tool 210 may be used to efficiently assemble multiple isolation transformers. The assembly includes multiple stations for performing the steps for assembling a transformer assembly. In one example, the assembly is a carousel with five workstations. The workstations each include a slot 212 which is shaped to securely hold core halves 130 and 131. These workstations also include first and second knobs 211 which are spaced to hold the windings of the transformer 186 in place. In operation, the secondary ferrite core half 131 is inserted into slot 212 of the tool 210 (FIG. 12A). Then, the secondary winding coils 144 and 146 are placed on top of the core half 131 so that the holes 154 are aligned with the center bar 134. Next, isolation tape layer 148 is placed on top of secondary core half 131, by standard automated tape dispensing equipment 220 (FIG. 12B). The primary winding coils 140, 142 are then placed on top of the tape layer 148, and the primary core half 130 is then placed on top of the primary winding coils 140, 142 using standard pick and place equipment (FIG. 12C).
Then, an arm 216 is lowered onto the transformer 186 to lift the transformer 186 from the tool 210 (FIG. 12D). As shown in FIG. 12E, the tool 210 includes a hinge 218. Once the transformer assembly 186 is lifted off the platform 210, the tool 210 is pivoted sideways either manually or automatically about the pivot point of hinge 218. Arm 216 then lowers the transformer 186 into the insertion tool 200 for placement into the plastic carrier 170 as described previously.
Other embodiments are also within the scope of the following claims.
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An isolation transformer comprises two core pieces mounted to cooperate to provide flux paths, one of the core pieces being shaped so that a central flux path is defined by a central leg of the core, at least two magnetically coupled windings surrounding the central flux path, and an isolation layer sandwiched between the windings.
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BACKGROUND OF THE INVENTION
[0001] I. Field of the Invention
[0002] This invention relates generally to electronic transducers for use in monitoring snoring episodes during sleep studies, and more particularly to a transducer especially designed to be worn on the nose for producing an electrical output proportional to vibration of selected portions of the nose as snoring takes place.
[0003] II. Discussion of the Prior Art
[0004] In U.S. Pat. No. 5,311,875 to Stasz, which is hereby incorporated by reference, there is described a system for electronically monitoring breathing patterns. The system included a transducer, the active element of which comprises a film of polyvinylidene fluoride (PVDF). As those skilled in the art appreciate, this material exhibits both pyoelectric and piezoelectric properties.
[0005] In accordance with the Stasz '875 patent, the transducer was adapted to be mounted on the upper lip of a subject where it would be exposed not only to vibration resulting from snoring but also thermal differences due to respiratory air flow during nasal breathing. The piezoelectric properties of the PVDF film produces a signal proportional to vibration and the pyroelectric properties produces a signal proportional to temperature fluctuations. In a subsequent Stasz et al. U.S. Pat. No. 6,254,545, there is described a combination thermal and vibration sensor for use in sleep monitor equipment where, again, a thin film of PVDF material is the active element. The PVDF film layer is sandwiched between an outer adhesive tape layer and an inner double-sided layer of adhesive tape. The transducer was particularly shaped for placement on the upper lip such that air entering and leaving the nostrils would impinge upon the transducer and so that a further portion is suspended from the upper lip but overhangs the mouth. The contents of the Stasz '545 patent are also hereby incorporated by reference as if set forth in full herein.
[0006] U.S. patent application Ser. No. 09/634,148, filed Aug. 8, 2002, which is assigned to the assignee of the present application, describes a vibration transducer based upon PVDF technology where the transducer comprises a generally rectangular patch that is adapted for placement on a subject's throat for the purpose of picking up vibrations caused by snoring.
[0007] Experience has shown that while each of the above-described transducer designs successfully operates for its intended purpose, each has its own type of defect that some patients find objectionable. In particular, the Stasz '875 patent and the Stasz et al. '545 patent are designed to be adhesively adhered to a patient's upper lip. If the person that is the subject of a sleep study has a moustache, it becomes somewhat difficult to adhesively affix the transducer to the upper lip and the moustache prevents more intimate contact with the skin of the lip such that vibrations produced by snoring are greatly attenuated. Moreover, subjects have complained about an objectionable tickling response when the transducer is affixed to the upper lip. The transducer that is the subject of pending application Ser. No. 09/634,148 must be placed at a so-called “sweet spot” on the neck, which is sometimes difficult to locate. In locating it, the subject is asked to hum and while doing so, the technician at the sleep lab must feel about the subject's throat to find the location where the vibration resulting from the hum is a maximum.
[0008] It is accordingly a principal object of the present invention to provide a vibration transducer that obviates the drawbacks mentioned above while still providing a robust electrical output signal during episodes of snoring so that information relating to snoring patterns can be discerned.
SUMMARY OF THE INVENTION
[0009] In accordance with this invention, there is provided a thin, flexible, laminated vibration transducer that is adapted for placement on a subject's nose for producing an electrical signal related to snoring episodes. The transducer comprises an outer layer of adhesive tape having adhesive on one major surface thereof. An intermediate layer of a flexible, conformable plastic film exhibiting piezoelectric properties and having a pattern of metallization on opposed major surfaces thereof is adhered to the outer layer of adhesive tape. First and second elongated conductors or wires, each having an electrode at one end and an electrical connector at another end are arranged such that the electrode on the first conductor is held in contact with the pattern of metallization on one of the opposed major surfaces of the layer of plastic film by the outer layer of adhesive tape and the electrode on the one end of the second conductor is held in contact with the pattern of metallization on the opposite side of the film layer using an inner layer of adhesive tape that has adhesive on each of its opposed major surfaces. The outer and inner layers of adhesive tape have a generally rectangular portion for spanning the dorsum of the nose and at least one integrally attached pad portion for attachment to an ala nasi.
[0010] It has been determined that the vibration of the ala nasi during snoring is readily detected by a PVDF transducer.
DESCRIPTION OF THE DRAWINGS
[0011] The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts.
[0012] [0012]FIG. 1 is a perspective view of a first embodiment of the invention;
[0013] [0013]FIG. 2 is an exploded view of the embodiment of FIG. 1;
[0014] [0014]FIG. 3 is an exploded sectional view of the embodiment of FIG. 1;
[0015] [0015]FIG. 4 shows the embodiment of FIG. 1 in place on the nose of a subject;
[0016] [0016]FIG. 5 is a perspective view of an alternative embodiment of the invention;
[0017] [0017]FIG. 6 is an exploded view of the embodiment of FIG. 5; and
[0018] [0018]FIG. 7 is a view illustrating the embodiment of FIG. 5 affixed to the nose of a subject.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the device and associated parts thereof. Said terminology will include the words above specifically mentioned, derivatives thereof and words of similar import.
[0020] Referring first to FIG. 1, there is indicated generally by numeral 10 a nasal vibration sensor in accordance with the present invention. It comprises a generally rectangular portion 12 with integrally attached polygonal pad portions 14 and 16 on opposed ends of the central rectangular portion. The pad portions may be polygonal in shape, as illustrated, or they may be somewhat rounder or oval in shape. Exiting opposed ends of the transducer are electrical conductors or wires 18 and 20 which lead to connectors 21 and 22 that are adapted to mate with input terminals of an amplifying and signal processing circuit (not shown).
[0021] Referring next to FIG. 2, the exploded view shows that the transducer is of a laminated construction, having an outer layer 24 of adhesive tape, an intermediate layer of polyvinylidene fluoride (PVDF) film 26 and an inner layer 28 of double-sided adhesive tape with an adhesive layer on opposed major surfaces thereof.
[0022] The PVDF film 26 has a layer of metallization 28 on opposed major surfaces thereof. The metallization is represented in FIG. 2 by the cross-hatching on the PVDF film layer 26 . It is coextensive with the outer layer 24 in terms of area.
[0023] With continued reference to FIG. 2, it will be seen that on the end of the conductor or wire 18 is an electrode member 30 and on the end of the wire 20 opposite from the connector 22 is a similar electrode member 32 . In its laminated condition, the electrode 30 is held in contact with the layer of metallization 28 on the upper surface of the film layer 26 while electrode 32 engages the pattern of metallization on the undersurface of the layer 26 .
[0024] Referring now to FIG. 3, which is an exploded cross-sectional view taken through the transducer 10 , it will be seen that there is an adhesive layer 25 on the undersurface of the tape substrate 24 . Likewise, the tape substrate 29 has an adhesive layer 34 on its upper surface and at an adhesive layer 36 on its lower or undersurface. To protect the adhesive layer 36 from contamination prior to use, a release liner 38 , which is relatively unaggressively adhered to the adhesive layer 36 is provided. The adhesive layer 36 on the underside of tape substrate 29 is selected so as to be comfortably removable from a subject's skin, yet adherent enough so as to maintain the transducer in place for a period of several hours.
[0025] Once laminated, the adhesive layer 25 bonds to the adhesive layer 34 sandwiching the electrode 30 , the PVDF film layer 26 and the electrode 32 therebetween. Without limitation, the rectangular portion 12 may be in a range of 3 cm to 5 cm long and 7 mm wide. The pads 14 and 16 may have an area of about 2.25 t0 3 sq. cm.
[0026] Referring now to FIG. 4, in use, the release liner 38 is peeled free from the adhesive layer 36 and the rectangular portion 12 of the laminated transducer is placed across the dorsum of the subject's nose and with the pad areas 14 and 16 being adhesively adhered to the ala nasi. The wires 18 and 20 pass over the subject's cheeks and behind the ears where a connection is made between the connectors 21 and 22 and an electronics module (not shown) for receiving and processing signals derived from the transducer 10 . It is found that when a person snores, the ala nasi vibrate and those vibrations are picked up by the PVDF film transducer and converted to an electrical signal proportional to the detected vibration signal.
Alternative Embodiment
[0027] Referring to FIGS. 5 - 7 , the alternative embodiment differs from the previously described embodiment in only two respects. First, only one pad 16 ′ is integrally attached to one end of the rectangular portion 12 ′ of the transducer and the PVDF film layer 26 ′ is coextensive with the pad area of the outer layer of adhesive tape 24 ′.
[0028] When the transducer 10 ′ is laminated, the adhesive on the undersurface of the outer adhesive tape layer 24 ′ holds the electrode 30 ′ to the upper surface of the PVDF film layer 26 ′. Likewise, the adhesive layer on the upper surface of the tape 29 ′ adheres the electrode 32 ′ to the pattern of metallization on the undersurface of the PVDF film layer 26 ′. Furthermore, the adhesive on the undersurface of the outer tape layer 24 ′ bonds to the adhesive on the upper surface of the inner adhesive tape layer 29 ′ except where the film layer 26 ′ is interposed. A release liner is also adhered to the under surface of the inner layer 29 ′ to protect the adhesive on that surface prior to its being used to adhere the transducer device to the nose of a subject.
[0029] [0029]FIG. 7 shows the alternative embodiment of FIGS. 5 and 6 affixed to a subject. Here, the release layer has been removed and the adhesive on the under surface of the layer 29 ′ attaches the transducer of the subject's nose such that the rectangular portion 12 ′ of the transducer overlays the dorsum and the pad area 16 ′ is bonded to the ala nasi on only one side of the side.
[0030] The choice of using a transducer as in FIG. 4 or as in FIG. 7 can depend on the type of data recorder that may be available in a sleep lab. If higher amplitude input signals are required, the transducer of FIG. 4 would be the choice. The transducer of FIG. 4 also offers an advantage of added security in the event one pad area should come loose. The sensor of FIG. 7 offers a lower cost alternative.
[0031] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.
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A vibration transducer specially configured for attachment to a subject's nose for producing an electrical output signal relating to a subject's snoring pattern. The transducer is shaped so as to have a rectangular portion for bridging the dorsum at least one polygonal pad area adapted to be adhesively secured to the ala nasi. The transducer is a laminated arrangement incorporating a polyvinylidene fluoride film exhibiting piezoelectric properties.
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If an Application Data Sheet (“ADS”) has been filed on the filing date of this application, it is incorporated by reference herein. Any applications claimed on the ADS for priority under 35 U.S.C. §§119, 120, 121, or 365(c), and any and all parent, grandparent, great-grandparent, etc., applications of such applications, are also incorporated by reference, including any priority claims made in those applications and any material incorporated by reference, to the extent such subject matter is not inconsistent herewith.
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of the earliest available effective filing date(s) from the following listed application(s) (the “Priority Applications”), if any, listed below (e.g., claims earliest available priority dates for other than provisional patent applications or claims benefits under 35 U.S.C. §119(e) for provisional patent applications, for any and all parent, grandparent, great-grandparent, etc., applications of the Priority Application(s)).
PRIORITY APPLICATIONS
U.S. patent application Ser. No. 13/483,970 entitled “Bicycle Bag,” filed on May 30, 2012, and U.S. Provisional Patent Application Ser. No. 61/492,183 entitled “Bicycle Bag,” filed on Jun. 1, 2011.
RELATED APPLICATIONS
If the listings of applications provided herein are inconsistent with the listings provided via an ADS, it is the intent of the Applicants to claim priority to each application that appears in the Priority Applications section of the ADS and to each application that appears in the Priority Applications section of this application.
All subject matter of the Priority Applications and the Related Applications and of any and all parent, grandparent, great-grandparent, etc., applications of the Priority Applications and the Related Applications, including any priority claims, is incorporated herein by reference to the extent such subject matter is not inconsistent herewith.
TECHNICAL FIELD
This disclosure relates to a bicycle bag and, in particular, to a bicycle bag that provides protection from the elements while the bike with bicycle bag are on a rack, and that can be used with a large variety of different bicycle and rack types.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings, in which:
FIG. 1A depicts an exemplary tray-type bicycle rack;
FIG. 1B depicts another exemplary tray-type bicycle rack;
FIG. 1C depicts an exemplary post-type bicycle rack;
FIG. 1D depicts an exemplary fork-type bicycle rack;
FIG. 2 depicts one embodiment of a bicycle bag; and
FIG. 3 depicts another embodiment of a bicycle bag.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
When a bicycle is secured to a rack the bicycle can become dirty or damaged due to exposure to the elements, road debris, vandalism, theft, and the like. As used herein a “rack” refers to any mechanism for securing a bicycle including, but not limited to: a vehicle rack configured to secure one or more bicycles to a vehicle for transport, a storage rack to storing a bicycle, a parking rack for bicycle storage, or the like. Bicycle covers or (bicycle “bags”) can be used to reduce this exposure. However, most existing bicycle bags do not provide sufficient protection. Moreover, bicycle bags that attempt to provide additional protection by covering the bicycle while in transit are often incompatible with certain vehicle rack systems, making their use dangerous and impractical. Moreover, these bags can be incompatible with certain bicycle types or frame configurations and/or may prevent bicycles from being “packed together” for transport. In some cases, when a bicycle is mounted on a vehicle rack, the bicycle (or bicycle bag) may obscure portions of the lighting system of the vehicle, such as the brake lights, turn signals, backup lights, and the like.
The bicycle bag disclosed herein addresses these and other shortcomings. The disclosed bicycle bag provides full coverage for a bicycle while on a rack. As used herein “full coverage” refers to a bicycle being fully enclosed by a bag, such that the bicycle is protected from outside elements, such as moisture, road debris, or the like. Accordingly, “full coverage” refers to a bicycle being fully enclosed within material of the bicycle bag, with no portions of the bicycle protruding therefrom. In some embodiments, the bicycle bag includes resealable openings configured to allow the bicycle bag to be used with a large variety of different rack types. The openings may be adapted such that the bicycle is protected whether or not the openings are in use. The disclosed bicycle bag may include pockets adapted to receive a lighting system, which may be used when the bicycle bag obscures the lighting system of the vehicle.
Various embodiments of a bicycle bag are disclosed herein. The disclosed bicycle bags provide advantages over existing bags. The features described with respect to the various embodiments may be combined in any suitable fashion.
The bicycle bag disclosed herein may be configured to allow a bicycle enclosed therein to be secured to a plurality of different rack types and/or securing mechanisms, which may include, but are not limited to: a tray-type rack, a post-type rack, a fork rack, bicycle straps, J-hooks, arm clamps, or the like.
FIG. 1A depicts an exemplary tray-type bicycle rack 170 . The rack 170 may comprise a J-bar to secure a wheel of a bicycle and one or more wheel trays. The one or more wheel trays may comprise respective straps for securing bicycle wheels thereto. FIG. 1B depicts another exemplary tray-type rack. The wheel tray of the rack 172 may comprise one or more wheel straps for securing a bicycle to the tray. The rack 172 may comprise a stabilizer bar configured to secure a bicycle in an upright position. The arm clamp may be configured to releasably secure one or more frame members of a bicycle (e.g., the downtube of a bicycle). As shown in FIG. 1B , the arm clamp may be configured to secure a bicycle in an upright position on the rack 172 . FIG. 1C depicts an exemplary post-type rack 174 . The rack 174 comprises one or more posts to which a bicycle frame may be secured. The one or more posts may comprise respective straps for securing a bicycle thereto. FIG. 1D depicts an exemplary fork-type rack 176 . The rack 176 may comprise a wheel tray having one or more straps to secure a bicycle wheel thereto. The rack 176 may further comprise a fork receptacle for securing a bicycle frame.
FIG. 2 depicts one embodiment of a bicycle bag 200 configured to allow a bicycle enclosed therein to be secured to a plurality of different rack types. The bicycle bag 200 may be constructed of any suitable material including, but not limited to: canvas, Kevlar®, neoprene, nylon, polyester, plastic, rigid plastic, metal, or the like, and/or combinations of different materials. The bag 200 (or portions thereof) may be formed from materials that are resistant to the elements. For example, the bag 200 may be formed from materials that provide protection from moisture (e.g., water proofing), provide ballistic protection from high-velocity road debris, are tamper resistant (e.g., include structural members, such as Kevlar® or metallic filaments or fibers, that resist cutting or tearing), or the like. In some embodiments, portions of the bag 200 (and/or the openings 203 and 204 therein) may be formed from flexible materials capable of adapting to different bicycle 201 and/or rack configurations. For example, the materials forming the opening 203 and/or resealable closure 243 thereof (discussed below) may be capable of expanding and/or deforming to adapt to different rack and/or bicycle 201 types. The flexible portions may be configured to allow the bag 200 to enclose bicycles 101 of different sizes and/or types.
As illustrated in FIG. 2 , bottom portions 211 and 212 of the bag 200 may be configured to generally conform to the shape of a bicycle 201 disposed therein. For example, the portion 211 may be configured to conform to the curvature of the front wheel 221 and the portion 212 may be configured to conform to the curvature of the rear wheel 222 . The portions 211 and 212 may be configured to allow the bag 200 to be used with bicycle racks that secure the bicycle 201 using curved wheel trays, such as the tray-type bicycle racks 170 , 172 , and/or 176 . The curvature of the bottom portions 211 and 212 of the bag 200 , allows a bicycle 201 disposed within the bag 200 to be secured by such a rack by, inter alia, securing the wheels 221 and 222 of the bicycle 201 within curved wheel trays of the rack.
The bag 200 may further comprise one or more resealable openings 204 in the wheel portions 211 and/or 212 . The openings 204 may be configured to allow a strap (or other securing mechanism) to pass through the bag 200 to secure one or more of the wheels 221 and/or 222 to, inter alia, a tray of a tray-type rack. The openings 204 may allow a securing mechanism to pass through the bag 200 and bicycle wheel 221 / 222 when the bicycle 201 is in the bicycle bag 200 . The openings 204 may comprise respective resealable closures 224 , which allow the bicycle 201 to be placed within the bag 200 and/or removed from the bag 200 (e.g., by disengaging the resealable closures 224 of the openings 204 ). The resealable closure 224 may comprise any suitable mechanism including, but not limited to: VELCRO®, a zipper, fastening straps, buttons, or the like. The resealable closure 224 may be configured to protect the bicycle 201 from the elements (e.g., moisture, debris, etc.). The openings 204 (and resealable closures 224 ) may be configured to avoid impinging on structural elements (e.g., spokes) of the bicycle 201 . Accordingly, in alternative embodiments, the openings may be narrowed and/or oriented vertically (along the radius of the wheels 221 and/or 222 ) so that the openings 204 may accept a securing member of a rack, while minimizing the chance of the openings impinging on wheel spokes or other components of the bicycle 201 . In some embodiments, the openings 204 may not be resealable, but may comprise one or more gaskets, flaps, elastics, or the like, that are configured to protect the interior portion of the bag 200 from the elements.
The bag 200 may further comprise resealable openings 205 disposed near the top portions 213 and 214 of the bag 200 . The resealable openings 205 may comprise respective resealable closures (not shown) configured to selectively open and/or seal the openings 205 . The openings 205 may be used to secure the bicycle 201 (and bag 200 ) to an upper portion of a rack (e.g., an over the wheel rack). As depicted in FIG. 2 , the openings 205 may be configured to prevent impinging on the structural components of the bicycle 201 (e.g., the wheels 221 , 222 and/or the spokes thereof).
In some embodiments, the bag 200 comprises a resealable opening 203 disposed near the center of the bag 200 . The opening 203 may be configured to create an opening within a diamond portion 203 of the bicycle 201 frame (under a top-tube of and/or above a down tube of the bicycle 201 ). The resealable opening 203 may be configured to allow the bicycle 201 to be secured to a post-type rack (e.g., a rack that secures a frame of the bicycle 201 to one or more posts or the like, such as the bicycle rack 174 ). For example, the opening 203 may be configured to provide for passing one or more posts of a post-type rack through the bicycle 201 within the bicycle bag 200 , such that the bicycle 201 may be secured thereto.
The opening 203 may be opened by disengaging the resealable closure 243 , which allows the bicycle 201 to be placed within the bag 200 and/or removed from the bag 200 . The resealable closure 243 may comprise any suitable mechanism including, but not limited to: VELCRO®, a zipper, fastening straps, buttons, or the like. The resealable closure 243 may be configured to prevent the elements (e.g., moisture, debris, etc.), from entering the interior of the bag 200 . The resealable closure 243 may be disengaged (e.g., opened) to allow the bicycle 201 to be placed within the bag 200 (or removed therefrom). The resealable closure 243 may re-sealed when the bag 200 is used for transport. In some embodiments, the opening 204 may not be resealable, and may comprise one or more gaskets, flaps, elastics, or the like, to protect the interior of the bag 200 from the elements.
In some embodiments, a top portions 213 and 214 of the bag 200 are configured to conform to the top portion of each wheel 221 and 222 . The top portions 213 and 214 allow the bicycle 201 (within the bag 200 ) to be secured to a “J-shaped” rack that secures the bicycle 201 using one or more “over-the wheel” J-shaped members, such as the bicycle rack 172 of FIG. 1A . Similarly, the portions 213 and 214 may allow the bicycle 201 and bag 200 to be secured to conventional shaped bicycle parking racks.
Although a particular set of resealable openings 203 , 204 , and/or 205 are depicted herein, one of skill in the art would recognize that the bag 200 could be adapted to include additional openings configured to allow the bag 200 to be used with different rack types and/or different bicycle 201 configurations. Accordingly, the disclosure should not be read as limited to any particular set of openings. For example, in some embodiments, the bag 200 may include one or more openings (not shown) or tabs (not shown), which may be used to secure or lock the bag 200 to a rack (or other structure).
In some embodiments, the bag 200 comprises one or more pockets 230 . The pockets 230 may be integrated into the bag 200 itself and/or may be removably attached thereto. The pockets 230 may be configured to receive tail lights 232 . The tail lights 232 may comprise any suitable lighting mechanism including, but not limited to: brake lights, turn signals, backup lighting, etc. The tail lights may be secured within the pockets 230 without the need for special brackets or other mechanisms. Accordingly, in some embodiments, the pockets 230 include a securing member 234 or flaps adapted to secure a tail light 232 therein (e.g., a zipper closure, VELCRO®, or the like). An exterior facing portion of the pockets 230 may be formed from a transparent material to allow light from the tail lights 232 to emit therefrom.
The bag 200 may provide an electrical connection between the pockets 230 and an exterior portion of the bag 200 . For example, the bag 200 may include an electrical connection 236 configured to receive an electrical connection from a vehicle, such as a trailer hitch electrical connection or the like. The electrical connection 236 may be disposed on a lower portion of the bag 200 to be proximate to a hitch electrical connection of a vehicle. The electrical connection 236 may be electrically coupled to each of the one or more pockets 230 . Accordingly, each of the two or more pockets 230 may include an electrical connection (not shown) in electrical communication with the electrical connection 236 . The electrical coupling may be implemented using conductors embedded within material of the bag 200 , conductors in the interior of the bag 200 , conductors along the exterior of the bag 200 , or the like. In some embodiments, the bag 200 may also comprise an electrical coupling output (not shown) to connect two or more of the bags 200 electrically in serial.
The bag 200 may comprise a resealable closure (not shown) along a bottom portion of the bag 200 . The resealable closure may be selectively opened to allow a bicycle 201 to be placed within the bag 200 and/or removed therefrom. The resealable closure may comprise any suitable mechanism including, but not limited to: Velcro®, a zipper, buttons, or the like. The resealable closure may be configured to protect the bicycle 201 from the elements when closed. Accordingly, the resealable closure may be waterproof and/or tamper resistant. In some embodiments, the resealable closure may include a locking mechanism to prevent the resealable closure from being opened. Alternatively, or in addition, the bag 200 may comprise a resealable closure along the top portion of the bag 200 . The top-portion resealable closure may allow a bicycle 201 to be placed within (or removed) from the top portion of the bag 200 .
The bag 200 may further comprise a portion 250 configured to allow the pedals and/or crank of the bicycle 201 to rotate therein. The pedals and/or crank may rotate within an arc 252 within the bag 200 . Accordingly, the portion 250 may comprise a sufficient interior volume to accommodate various bicycle pedal and/or crank configurations. The rotation 252 of the pedals and/or crank may facilitate arranging two or more bicycles next to one another on a rack. For example, the pedals of the two or more bicycles may interfere with one another when oriented side-by-side in a rack. The rotation 252 of the bicycle 201 pedals and/or crank may allow the pedals to offset one another, allowing the bicycles to be placed in closer proximity.
As discussed above, the bag 200 may be formed from a material configured to provide protection from the elements while the bicycle 201 is transported on a vehicle. Accordingly, the bag 200 may be formed from waterproof material and/or material that provides ballistic protection (e.g., protection from high-velocity road debris).
FIG. 3 illustrates other aspects of a bicycle bag as disclosed herein. The bicycle bag 300 comprises a resealable opening 315 running along a top rear portion and bottom of the bag 300 . The resealable opening 315 may be configured to receive a bicycle into an interior portion of the bag 300 . As described above, portions of the bag 300 may be formed from deformable and/or flexible material, such as spandex, neoprene, or the like. In the FIG. 300 example, a handlebar compartment 360 , a top-tube portion 361 , and a seat portion 362 of the bag may be formed from a deformable material, which may allow the bag 300 to accommodate bicycles of different sizes and/or configurations. For example, the handlebar compartment 360 of the bag may be configured to receive handlebars of varying widths and/or heights. Similarly, the top tube portion 361 may be deformable to accommodate bicycles of varying lengths, and the seat portion 362 may be deformable to accommodate bicycles of varying height. The bicycle bag 300 may be provided in different sizes and/or configurations. For example, the bag 300 may be provided in small, medium, and/or large sizes to accommodate a large range of bicycles sizes (e.g., frame sizes from 40 to 64 cm). Similarly, the bag 300 may be provided with different handlebar compartment 360 types, including, but not limited to: a road bike compartment configured to receive road bike handlebars, a mountain bike compartment configured to receive wider mountain bike handle bars, and/or a cruiser compartment configured to receive wide bar types. In some embodiments, the handle bar compartment 360 may be removable and/or modular, such that the bag 300 may switch between road, mountain, and/or cruiser handler bar compartments. Alternatively, or in addition, the handle compartment 360 may comprise one or more straps, expansion sleeves, or the like, to allow a user to change the configuration of the handlebar compartment 300 (and/or other portions of the bag 300 ) to accommodate a particular size and/or style of bicycle.
As shown in FIG. 3 , the opening 103 may be provided in a diamond shape to fit a wide variety of post-type racks. The opening 203 may be resealable, as described above. The bag 300 may further comprise a seat-tube opening 306 configured to allow a rack to secure a seat tube of a bicycle within the bag 300 . A down-tube opening 307 may be configured to allow a rack to secure a down tube of a bicycle within the bag 300 . In some embodiments, the opening 204 may be configured to allow a fork of the bicycle to protrude from the bag 300 , such that the fork may be secured to a fork-type rack (e.g., rack 176 ).
As described above, bottom portions 211 and 212 of the wheel compartments 281 and 282 may be configured to conform to a contour of the wheels of the bicycle. Accordingly, the wheel compartments 281 and/or 282 may be configured to allow the wheels of the bicycle to be secured to a tray-type rack and/or be secured using a wheel slot or clamp (or similar mechanism). As shown in FIG. 3 , the wheel compartment 281 may be configured to allow a front portion 283 A and/or rear portion 284 A of the front wheel to be secured to a tray and/or wheel slot or clamp. The wheel compartment 282 may be configured to allow a front portion 283 B and/or read portion 284 B of the rear wheel to be secured to a tray and/or wheel slot or clamp. In addition, the openings 204 may be used to secure the front and/or rear wheels to various rack types, as described above.
Top portions 213 and 214 of the wheel compartments 281 and 282 may conform to top portions of the bicycle wheels. As such, the wheel compartments 281 and/or 282 may be configured to allow the bicycle to be secured to an over-the-wheel rack, a J-hook, or similar mechanism. The bag 300 may further comprise pockets 230 to receive lighting, a crank compartment 250 configured to allow a bicycle crank and/or pedals to rotate within the bag 300 , as described above.
It will be understood by those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles presented herein. For example, any suitable combination of various embodiments, or the features thereof, is contemplated.
Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.
Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.
Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment.
The claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements specifically recited in means-plus-function format, if any, are intended to be construed in accordance with 35 U.S.C. §112 ¶6.
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A bicycle bag protects a bicycle while the bicycle is secured to a rack, such as a vehicle bicycle rack. The bicycle bag includes resealable openings configured to allow the bicycle (and bag) to be securely attached to a wide variety of different rack types. Additionally, because there is risk of obscuring the tail lights of a vehicle for rear-mount racks when a bicycle bag is on the bike and the bike on the rack, the bicycle bag includes pockets designed to support a tail-light system that can be connected to the vehicle to provide additional lighting and safety.
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FIELD OF THE INVENTION
The invention relates to a seat belt webbing and a method for manufacturing the same for a motor vehicle restraint system.
BACKGROUND OF THE INVENTION
Seat belts are used for example in motor vehicles, aircrafts and other mobile devices for restraining the occupant. To perform their function, the seat belts need to have a predetermined tensile strength. Furthermore, the seat belts should generally comprise a surface having as low friction as possible and a soft edge, in order that the occupant is obstructed by the seat belt as little as possible and the clothes of the occupant are not damaged.
The seat belt webbing comprises a plurality of warp threads running in the longitudinal direction which are connected with each other by a weft thread running transversely to the warp threads. During the weaving process, the weft thread is shot through the warp threads from one side of the belt webbing using a weft needle and is caught on the other side using a catch thread, so that when the weft needle is retracted the weft thread is not retracted with it. In the case of loading the seat belt webbing during an accident the warp threads are the load-bearing threads and therefore need to have a certain tensile strength, whereas the weft thread is loaded to a lesser extent and essentially forms the surface of the belt webbing. Thus, the weft thread should have better surface properties than the warp threads, however, in the sense of a softer surface may have a lower tensile strength than the warp threads.
From EP 1 514 962 A2, a belt webbing is known, which in the edge regions comprises warp threads having a different shrinkage characteristic than the warp threads in the central region. In the successive shoots, the weft thread is inter-woven with a varying number of warp threads, so that in the edge region certain warp threads, for example at every fourth or fifth shoot only, are looped around by the weft thread. After weaving the belt webbing it is subjected to a heat treatment, during which a soft edge is formed by intentionally shrinking the warp threads differently in the edge region.
Furthermore, seat belt webbings are known, in which the warp threads in the edge region are designed to be considerably finer than the warp threads in the central region. Owing to the finer warp threads in the edge region, the edge of the seat belt webbing is softer and the surface of the seat belt webbing is considerably more homogeneous, so that the sawing effect of the seat belt webbing when rubbing against the edge is considerably reduced.
It is the object of the invention to provide an enhanced seat belt webbing comprising a soft edge and a method for manufacturing the same.
SUMMARY OF THE INVENTION
For the solution of the object, it is proposed according to the invention that the catch thread is placed between the warp threads and is covered by the weft thread and/or the warp threads towards the surface of the seat belt webbing.
The catch thread itself in the seat belt webbing has the function to retain the weft thread in the reversal points during the weaving process, which is why it has to have a certain tensile strength, in order that it does not tear during the weaving process and consequently the weaving process needs to be interrupted. Surprisingly, the catch thread appearing on the surface has turned out to have a crucial co-influence on the hardness of the edge. Due to its function, the properties of the catch thread differ from the properties of the weft thread, so that owing to the catch thread appearing on the surface between the weft threads the surface becomes inhomogeneous, and the sawing effect of the edge when rubbing for example against the clothes of the occupant is increased. Due to the solution according to the invention the surface of the edge is now defined by the weft thread and/or by the warp threads only, as the catch thread is placed between the warp threads and is covered by the weft threads and/or the warp threads. The catch thread thus is no longer visible from the outside. A further advantage resulting from the invention is that both edges of the seat belt webbing thus are nearly identical, even if a weaving technique is used, in which a catch thread is provided on one side only, and the weft thread is inserted from one side only.
It generally is a disadvantage of inhomogeneous sides of the seat belt webbing that they wear away differently, and the seat belt webbing thus, after long-time wearing, gives the optical impression to the beholder of being of lower value. Furthermore, when the belt webbing is mounted with a misalignment the inhomogeneous edges may lead to an undesired noise occurring in the seat belt retractor during the retraction movement and extraction movement of the seat belt webbing. For this reason, when mounting the belt webbing in the seat belt retractor specific cost-incurring measures need to be taken, in order to prevent the seat belt webbing from being mounted incorrectly with a misalignment. Inhomogeneous edges further result in the seat belt webbing making additional noise when being pulled through the deflector, in the retraction forces and extraction forces of the seat belt webbing changing disadvantageously and in the belt bearing surface of the deflector being worn away unequally.
DESCRIPTION OF THE DRAWING
In the following, the invention is described in more detail on the basis of a preferred embodiment.
FIG. 1 shows a seat belt webbing according to the invention comprising a catch thread which is placed between the warp threads.
DETAILED DESCRIPTION OF THE INVENTION
The seat belt webbing may be subdivided into a center portion A and an edge portion B. In the center portion A, warp threads 1 are provided, which have a thread size of 900 to 2100 dtex and are designed as multifilaments comprising filaments which are not twisted or filaments which are twisted with up to 150 twists per meter length. The warp threads 1 have the function to absorb the tensile forces acting during the accident and, therefore, are particularly strong and thus also relatively stiff. In the edge portion B, finer warp threads 3 having a thread size of 400 to 1100 dtex are provided, which as well are designed as multifilaments comprising for example 28 filaments. The filaments further are twisted with each other up to 150 times per meter length.
Furthermore, a weft thread 2 is provided, which, while the belt webbing is woven, with a weft needle is shot from one side through a shed formed by two layers of warp threads 1 and 3 which are aligned at an angle relative to each other. At an edge of the seat belt webbing, the weft thread 2 is caught using a catch thread 5 and is crocheted with the same via a knitting needle. The weft thread 2 as well is designed as a multifilament having a thread size of 280 to 1100 dtex and comprises for example 96 filaments which are twisted with each other 130 times per meter length. Owing to the great number of filaments the weft thread 2 is particularly self-moveable, so that with the weft thread a particularly soft and homogeneous surface can be obtained. The catch thread 5 is designed as a multifilament as well and has a thread size of 280 dtex and comprises 48 filaments with 80 twists per meter. Furthermore, a lock thread 4 is provided, which is guided together with the catch thread 5 and provides a better coherence of the textile composite in the seat belt webbing.
As can be seen in FIG. 1 , the finer warp threads 3 of the edge portion B are interwoven with the weft thread 2 to form two layers 6 and 7 each with the weaving pattern being formed in such a way that, on one side, three warp threads 3 in a package III and, on the other side, one warp thread 3 in a package I are alternately passed by the weft thread 2 . The weft thread 2 is a single thread which during the weaving process is guided in a periodic to-and-fro motion and thereby effects the cross connection of the warp threads 1 and 3 and further forms at least a major part of the surface of the seat belt webbing.
At every second shoot, the weft thread 2 is only guided past the warp threads 3 and subsequently, when moving backwards, pulls the catch thread 5 to such an extent into the edge portion B that, in the finish-woven seat belt webbing, the same gets to rest between the warp threads 3 and is covered by the weft thread 2 towards the surface. The catch thread 5 preferably is only pulled into the edge portion B maximally up to the edge of the center portion A between the finer warp threads 3 , as the weave of the warp threads 1 to the weft thread 2 in the center portion A differs from the weave of the finer warp threads 3 to the weft thread 2 in the edge portion B. After said shoot of the weft thread 2 , the weft thread 2 at the next shoot is shot through at least a partial number of the warp threads 3 , preferably through one of the layers 6 or 7 , is then caught by the catch thread 5 and, while moving backwards, pulls the catch thread 5 as well as some of the warp threads 3 up to the center portion A. Thus, at the edge of the center portion A an overall soft edge with an inside catch thread 5 is generated, the exterior surface of which edge is formed by the weft thread 2 and the finer warp threads 3 only. As a result, an identical surface structure of the edges of the seat belt webbing is generated, even if the weft thread 2 is caught by the catch thread 5 on one side only, as the catch thread 5 is placed between the finer warp threads 3 and, towards the surface, is covered all over by the weft thread 2 , and thus does not appear on the surface.
In particular, the tensile load in the catch thread 5 should be chosen in such a way that the weft needle can pull back the catch thread 5 together with the weft thread 2 with the retraction or carry-along movement being automatically restrictable by the varying weave of the warp threads 1 and 3 . The weave of the warp threads 1 and 3 is the weaving pattern formed by the weft thread 2 which is shot through and the warp threads 1 and 3 which are moved thereby individually or together in groups. The weaving pattern in the present seat belt webbing in the center portion A is formed by two paired warp threads 1 each, which are alternately passed by the weft thread 2 on different sides. The weaving pattern and thus the weave of the warp threads 3 in the edge portion B is formed by the alternating groups I and III which are formed from three warp threads 3 or one single warp thread 3 each and are passed by the weft thread 2 on different sides. The movement of the warp threads 1 and 3 between each single shoot of the weft thread 2 here is not described in detail. However, knowing the commonly used weaving technique, the same can easily be deduced.
The proposed weave of the warp threads 3 in the edge portion B has turned out to be advantageous insofar as an edge can be obtained thereby having a thickness which is essentially identical to the thickness of the seat belt webbing in the center portion A.
The proposed seat belt webbing in particular provides the advantage that it comprises at least two nearly identical soft edges and, though, can be woven with one weft thread 2 only and a one-side guided catch thread 5 . Thereby, considerably higher working speeds can be obtained than is possible with belt webbings comprising soft edges according to the prior art. The loom can be operated with approx. 1500-1600 U/min resulting in the manufacturing costs of the seat belt webbing being significantly lower than for comparable seat belt webbings comprising soft edges.
A further advantage resulting from the invention is that the catch thread 5 is no longer allocated to a certain group of warp threads 1 or 3 , as is the case in the prior art. The catch thread 5 loses its orientation and is intentionally placed between the warp threads 1 and 3 without a predetermined orientation, so that the seat belt webbing in the area of the edge no longer shows a hardness distribution which is defined by the catch thread 5 appearing on the surface of the seat belt webbing.
While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation, and change without departing from the proper scope and fair meaning of the accompanying claims.
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A seat belt webbing has a plurality of warp threads ( 1, 3 ), a weft thread ( 2 ) which runs from one edge of the seat belt webbing to the other edge, periodically reversing the direction in reversal points and is interwoven with the warp threads ( 1, 3 ).The weft thread ( 2 ) in the reversal points in an edge portion (B) is folded back forming a loop, and a catch thread ( 5 ) which is fed through the loops of the weft thread ( 2 ).The catch thread ( 5 ) is placed between the warp threads ( 1, 3 ) and is covered by the weft thread ( 2 ) and/or by the warp threads ( 1, 3 ) towards the surface of the seat belt webbing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cleaning device for cleaning textile machines, said device being arranged for movement along the machine and having an overhead air-blowing arrangement provided with air connections, to which connections at least one vertically disposed air hose with openings directed on to the machine is connected.
2. Prior Art
Known cleaning devices for cleaning textile machines are normally provided with a blower housing designed to travel on rails above the textile machines. Extending from the housing on either side of the textile machine are normally two vertically disposed air hoses, one hose being used as a blower and the other as a suction hose in order to suck away the yarn flick. In this way several textile machines arranged one after the other, to form a bank or a row of machines, can be cleaned using one and the same device.
When the textile machines concerned are spinning machines, a yarn-attaching machine is provided for each spinning machine, which yard-attaching machine travels along the two sides of the bank of textile machines. This yarn-attaching machine projects out of the side zones of the textile machines.
It is well-known to arrange the hoses of the cleaning device at such an interval from the sides of the textile machines that no change between air hose and the yarn-attaching machine can occur. The space between the air hoses and each side of the textile machine, however, is then so large as to adversely affect the cleaning efficiency of the device. Again, frequently, the mutual space between the textile machines is insufficient to allow the hoses to be arranged in the indicated manner.
To avoid these disadvantages, it is well-known to connect the cleaning device to the yarn-attaching machine, so as to obtain a single traversing unit. This solution, however, has the disadvantage that the cleaning device can then only clean on one side of the textile machine, which results in a not inconsiderable increase in investment costs.
As will be apparent from the aforegoing, there is a need for a textile machine cleaning device which can traverse a textile machine or a bank of such machines independently of the yarn-attaching machine or of any other textile machine servicing apparatus, which will not impede the passage of said yarn-attaching machine or said apparatus along said machine or bank of machines, and which will efficiently clean said textile machines.
3. General Discussion of Present Invention
Accordingly, this invention consists in a textile machine cleaning device which is movable along a textile machine and which has at least one air hose, wherein said device comprises hose-moving means for automatically moving said air hose between a first position in which it is operative to effect cleaning of said textile machine and a second position in which it permits the unimpeded passage of any further device moving along said textile machine in the movement path of said cleaning device.
BRIEF DESCRIPTION OF DRAWINGS
So that the invention will be more readily understood and further features thereof made apparent, exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a diagrammatic plan view of first and second embodiments of the cleaning device;
FIG. 2 is a diagrammatic plan view of a third embodiment;
FIG. 3 is a side elevation of the embodiment of FIG. 2;
FIG. 4 is a diagrammatic plan view of a fourth embodiment;
FIG. 5 shows diagrammatically a fifth embodiment;
FIG. 6 shows diagrammatically a sixth embodiment; on the right-hand side of the figure the air hose is shown in its operative, cleaning position and on the left-hand side is shown in the position it occupies in the neighbourhood of the yarn-attaching machine; and
FIG. 7 is a diagrammatic plan view of a seventh embodiment of a cleaning device according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The cleaning device of FIG. 1 comprises a blower housing with a filter chamber 2 arranged to move backwards and forwards on the support structure 3 textile machine to be cleaned. The housing 1 is provided with air connections 4, 5, a blower hose 6 being connected to the connection 4 and a suction hose 7 to the connection 5.
In the embodiment shown in the bottom half of FIG. 1, the hose section between the air connections 4, 5 and substantially vertically extending parts 6', 7' of each air hose, is flexible, and preferably corrugated. The top parts of the substantially vertically extending hose sections 6', 7' are supported by a supporting and fixing device 8. The supporting and fixing device is assembled on an outwardly-projecting guide rail 9 which is preferably telescopic. The supporting and fixing device 8 carries a downwardly-projecting arm provided at its end with a guide roller 10. To a yarn-attaching device 11, there is attached a rail 12 having an entry ramp 12' at both ends thereof.
Normally, the hoses 6, 7 or the vertical hose sections 6', 7' have the position shown in FIG. 1 in full lines. However, as the cleaning device and yarn-attaching machine approach each other, the roller 10 will come into contact with one of the entry ramps 12' and this, in association with the roller 10, guides the supporting and fixing device 8 and with it the vertically extending hose sections 6', 7' outwards to the position shown in chain-dotted line. When the hoses 6, 7 are moved outwards, a spring 13 preferably arranged in the telescopic tube 9, is tensioned. The hoses 6, 7 are returned to their operative cleaning position when they have moved out of the area occupied by the yarn-attaching machine 11, i.e. when the roller 10 moves down the other ramp 12', by the action of said spring.
In the embodiment shown in the top half of FIG. 1, instead of the flexible hose sections, the air connections 14, 15 are in the form of telescopic ducts to whose forward ends the vertically extending hoses 6', 7' are connected. These telescopic ducts are extended when the roller 10 comes into contact with the rail 12. The mode of operation of this embodiment is identical to that of the embodiment shown in the bottom half of FIG. 1.
The cleaning device and the yarn-attaching machine may move towards one another during operation, or the cleaning device may overtake the yarn-attaching machine, because normally the speed of motion of the cleaning device is three times that of said machine.
In the embodiment shown in FIG. 2, the supporting and fixing device 8' of respective hoses 6, 7 is attached to one end of an arm 16 forming part of a triangular linkage 16, 20. The arm 16 is pivotally mounted at 17 to the blower housing 1 and filter casing 2. The other end of the arm 16 is articulated through a joint 18 to an arm 20 which is in turn articulated through a joint 19 to a threaded spindle 21. The spindle 21 is moved by a rotating spindle-nut 23, the nut 23 being powered by a motor 22.
A switch (not shown in the drawing) is provided which upon contact between the hoses and a yarn-attaching machine supplies a signal to the motor 22 causing the same to be energized. The nut 23 is then caused to rotate to effectively shorten the spindle 21 in the direction of the motor 22, so that the joints 18 execute a motion indicated by the circular arrows. Consequently, the arms 16 are pivoted outwardly and the hose sections 6', 7' describe a motion indicated by the circular arrows. As a consequence, the hose sections 6', 7' pivot outwardly and out of the path of the yarn-attaching machine. As soon as the cleaning device has moved out of the region occupied by the yarn-attaching machine, a further switch is activated which causes the motor 22 to rotate in the reverse direction, so that the hoses pivot inwardly.
The motor 22 in the indicated example is an electric motor. However, the motion can also be produced by a hydraulic or pneumatic motor and this also includes motors of piston type. The only requirement is that the motor should be capable of displacing the joint 19 parallel to the path of motion of the cleaning device. Within the framework of this concept, it is also possible for the piston of a piston-and-cylinder arrangement to act directly with its piston rod on the supporting and fixing device 8 or 8' and to move the hoses out and back without the use of any intermediate kinematic chain elements. Cylinder and piston will in this context preferably be disposed at right angles to the path of motion of the cleaning device.
FIG. 3 is a side elevation of the cleaning device of FIG. 2. The right-hand half of FIG. 2 illustrates the hose position during a cleaning operation and the left-hand half illustrates the hose position when the cleaning device is in the zone of the yarn-attaching machine 11.
The aforementioned switches may be mechanically or photoelectrically operated switches. Also, pressure switches are conceivable, these responding when the air flow from the blower hose 6' strikes them.
In the embodiment of FIG. 4, the hoses 6, 7 are supported by a common supporting and fixing device 8 which is in turn mounted on a telescopic guide rail 9. The motor 22' is arranged to rotate a threaded spindle 24 on which two threaded sleeves 25 are mounted. Between the two threaded sleeves 25 and the supporting and fixing device 8, in each case an obliquely disposed leader arm 26 is arranged. When the motor 22' rotates the threaded spindle 24, the two sleeves 25 move towards each other so that through the two lever arms 26 the supporting and fixing device 8, complete with hoses 6, 7, is moved outwards. With rotation of the spindle 24 in the opposite direction, the hoses are moved back. The motor 22' is actuated by the aforementioned switches.
In the embodiment of FIG. 5, instead of the threaded sleeves 25 of FIG. 4, sliding sleeves 25' are provided which can slide on the rod 24'. The sliding motion on the part of the sleeves 25' is produced by triangular linkages 27, 28, the link 28 being centrally arranged and exhibiting a lever arm 29 to which a roller 10 is attached. When the roller 10 contacts with rail 12, the two sleeves 25' are moved towards each other. The return motion is produced by a spring 13'. Articulated to each of the sliding sleeves 25' is a lever arm (not illustrated) corresponding to the lever arm 26 of the FIG. 4 embodiment, and the displacement of the hoses in the outward and inward directions takes place in the same way as described in relation to FIG. 4.
In the example shown in FIG. 6, the air hoses 6, 7 are designed as corrugated hoses, i.e. are resilient.
Connected to the blower housing 1 is a horizontal supporting arm 31 at whose outer end there is a joint 32 through which a lever arm 33 is articulated. The lever arm 33 is attached to the joint 34 through a hose clip 35. The hose clip and the joint 34 are located above the path of motion of the yarn-attaching machine 11. The lever arm 33 has an extension 36 to which, through the joint 37, the actuating arm 38 is articulated. The other end of the actuating arm 38 is connected at 39 to a servo-motor 40 arranged above the blower housing 1.
As the hose 6, 7 moves into the proximity of the yarn-attaching machine 11, the motor 40 is so operated that the arm 38 moves inwardly so that the hose 6, 7 is moved outwardly beneath the clip 35, outside the path of motion of the yarn-attaching machine. When the hose 6, 7 has moved out of the zone of the yarn-attaching machine 11, the motor 40 is actuated in the opposite direction so that the hose returns to its normal position as shown in the right-hand half of the drawing.
In the embodiment of FIG. 7, the two hoses 6, 7 are shown to be moved outwards to such an extent that their path of motion does not overlap that of the yarn-attaching machine 11. The blower hose 6 is provided with several nozzles 41 directed towards the textile machine. The path of motion of these nozzles 41 overlaps that of the yarn-attaching machine 11. The blower hose is provided at its top region with a swivel joint which has not been shown.
When the cleaning device moves into a area occupied by the yarn-attaching machine 11, the hose section carrying the nozzles 41 is pivoted through 90° so that the nozzles 41 move out of the path of motion of the yarn-attaching machine 11. The hose section carrying the nozzles 41 is rotated in opposition to the relative motion between the claning device and the yarn-attaching machine 11, i.e. the nozzles 41 always pivot away from the yarn-attaching machine 11. This is indicated in the drawing by the arrows.
The rotary motion can be produced quite simply by a lever arranged on the rotatable hose section and adapted to come into contact with part of the yarn-attaching machine. When the hose 6 moves out of the zone of the yarn-attaching machine 11, the rotatable hose section rotates back to its normal position, this being produced quite simply by one of two springs which are arranged on the rotatable hose section, and which act in opposite direction and restore the normal position of the nozzles 41.
The described and illustrated embodiments, although preferred, are exemplary and generally should not be considered restrictive, and the invention can be modified in many ways within the scope of the inventive concept.
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A textile-machine cleaning device, having a cleaning hose and adapted to generally move overhead of a textile machine, is provided with means whereby the hose can be moved automatically from a first position in which it is operative to clean said machine, and a second position in which it allows the unimpeded passage of a further device (e.g. a yarn-attaching machine) servicing said textile machine and moving in the same path of movement as the hose. Conveniently, the cleaning device operates in combination with said further device, which is provided with means coacting with said means for moving the hose so as to cause said hose to adopt one of said two positions. Seven embodiments are described and illustrated.
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BACKGROUND TO THE INVENTION
This invention relates to operating warp knitting machines.
Conventionally the guide bars of warp knitting machines are controlled by pattern wheel or pattern chains which are in effect cams pushing the guide bars against resilient means biassing them against the cams. Because the pattern chains and pattern wheels, though reliable in operation, are expensive in terms of time and money to construct and install in a warp knitting machine, alternative guide bar operation systems have been proposed. One such alternative system is described in our co-pending U.S. patent application Ser. No. 710,002, filed Mar. 11, 1985 filed contemporaneously herewith and comprises a hydraulic arrangement which can be operated under the control of a computer.
The use of a computer to control guide bar movements brings about the advantage that desired lapping instructions can by input much more readily than pattern wheels or chains can be assembled, and the testing of new fabric specifications becomes simplified and less costly.
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides improved computer control of warp knitting machine guide bar movement.
The invention comprises a method for operating the guide bars of warp knitting machines comprising feeding in to a computer desired lapping instructions said computer being programmed to discriminate between permitted and prohibited lapping movements and being operative to prevent the attempted execution of prohibited movements.
Said computer may be programmed to test instructions against a set of mandatory rules to discriminate between permitted and prohibited lapping movements. One of said mandatory rules may restrict overlaps to one needle space and another of said mandatory rules may restrict underlaps to a number of needle spaces determined in accordance with machine speed.
Said computer may be connected to feed control signals directly to guide bar operating means and be operative not to feed such signals if instructions fed in to said computer are for prohibited lapping movements.
Said computer may also be programmed to discriminate between effective and ineffective lapping movements. Said computer may be programmed to test instructions against a set of advisory rules to discriminate between effective and ineffective lapping movements.
One of said advisory rules may require each needle that knits at all to knit at least one yarn on each course. One of said advisory rules may require adjacent wales to be connected at some point in a repeat. One of said advisory rules may require that a laid-in yarn does not turn around an empty needle. And one of said advisory rules may require that a knitting guide bar must precede a laying-in guide bar.
The computer may be connected to feed control signals directly to guide bar operating means and be operative to feed such signals despite instructions fed in to said computer for ineffective lapping movements, but to draw attention to such instructions' being for ineffective movement.
Said computer may receive synchronisation signals from a warp knitting machine under its control, and may be operable to control the speed of operation of such a knitting machine.
Said computer may also be operable to control inching of said knitting machine.
Said computer, moreover, may be operable to stop a knitting machine under its control with its knitting elements in a predetermined position. Said predetermined position may be one in which excessive yarn tensions are avoided, and may even be one in which yarn tensions are minimised.
Said computer may monitor operating variables of a knitting machine under its control.
The invention also comprises apparatus for operating the guide bars of warp knitting machines comprising a computer adapted to receive lapping instructions and being programmed to discriminate between permitted and prohibited lapping movements and being operative to prevent the attempted execution of prohibited movements.
Said computer may comprise a keyboard for inputting instructions and a visual display unit adapted to display information relative to such instructions and to operation of a knitting machine under the control of the computer. The computer may be connected to control a knitting machine directly and to receive synchronisation signals from said machine.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of apparatus and methods for operating the guide bars of warp knitting machines in accordance with the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a diagrammatic representation of the apparatus,
FIG. 2 is a point diagram of a permitted guide bar lapping movement,
FIG. 3 is a point diagram of a prohibited movement,
FIG. 4 is a point diagram of another prohibited movement,
FIG. 5 is a point diagram of an ineffective movement, and
FIG. 6 is a point diagram of another ineffective movement.
FIG. 7 is a point diagram of another ineffective movement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus illustrated in FIG. 1 is for operating the guide bars 11 of a warp knitting machine and comprises a computer 12 adapted to receive lapping instructions and programmed to discriminate between permitted and prohibited lapping movements and operative to prevent the attempted execution of prohibited movements.
The guide bars 11 are moved by actuators 13 which can be hydraulic piston-in-cylinder arrangements controlled by electrically operated valves receiving electric operating signals from the computer 12.
The computer 12 comprises a visual display unit (VDU) 14 comprising a screen and a keyboard 15 as well as a stored program device 16 which can load different programs into the computer 11. The device 16 can for example be a disc or tape drive, or even a ROM or non-volatile RAM or EPROM cartridge.
Warp knitting constructions are specified in terms of lapping movements and threading instructions for the guide bars and can be represented graphically. FIG. 2 shows a point diagram of a two guide bar fabric in which the front bar is knitting open chain stitches in which each thread always knits on the same needle, and the back Bar is laying-in over two needles. These are permitted movements which are also effective. By "permitted" is meant that the movements give rise to no problem in operating the machine such as would cause damage to the yarns or knitting elements. "Effective" means that the movements will result in a fabric being knitted.
For the simple construction shown in FIG. 2 it would be specified, so far as threading is concerned, that the two bars are full set threaded, by which is, of course, meant that each guider is threaded with a yarn.
The notation conventionally adopted to describe the lapping motions for the FIG. 2 construction is
Front Bar: 1-0, 0-1 and repeat
Back Bar: 0-0, 2-2 and repeat
The numbers indicate the height of link required in the conventional pattern chain to produce the required lapping movement, but equally well indicate the position of the guide bar, in terms of needle spaces, relative to a starting position ("0") at the pattern wheel or chain end of the machine.
This is a convenient notation, also, to input lapping instructions to a computer since, given the gauge of the machine, of which the reciprocal (in suitable units) gives the needle spacing, the numbers completely specify the required positions of the guide bar before and after each stitch-forming motion of the needle bar.
Threading instructions can be specified in a variety of ways. One way is to diagrammatically represent the filled guiders as a "1" and the empty guiders as a ".", but apart from the "full set" (which means, obviously, all guiders threaded) and "half set", which means alternate guiders threaded, the usual instruction is given in the form "1 in, 2 out" or "2 in, 2 out" and so on. Clearly, a computer can be programmed to "understand" any of these instructions.
FIG. 3 shows a lapping instruction that would ordinarily be regarded as prohibited. Notated 0-2, 2-0 and repeat, it forms, or attempts to form, an overlap over two needles. Ordinarily this causes high tensions which can damage the yarns and bend or break the knitting elements. The reason for this is that both needles attempt to form stitches and consume, even if only temporarily, comparatively long lengths of yarn in the loop formation. Occasionally this is permitted, but ordinarily fabrics do not use this kind of construction and the computer may be programmed to prevent operation of the machine if such a construction is inadvertently instructed.
FIG. 4 shows a three needle overlap notated as 0-3, 3-0. Such a construction is definitely prohibited.
FIG. 5 shows a two guide bar lapping movement in which the front Bar lays-in behind two needles and the back Bar knits open chain stitch. This would be ineffective to produce a fabric, although the knitting machine could be run. In the event of this instruction being given, the computer would permit operation of the machine, but return an error message that the construction would be ineffective.
FIG. 6 shows another ineffective movement in which the front Bar does not knit on every course and the back Bar does not knit on any needle-again, with this construction the computer would permit operation of the machine but return an error message that the movement would be ineffective.
FIG. 7 illustrates a construction in which the front and back bars make a sideways connection between wales of stitches every few courses. Were it not for this sideways connection in courses 1/2, 6/7 and so on, the computer would permit operation of the machine, but return an error message that the movement would be ineffective.
The computer program can comprise a set-up module in which lapping and threading instructions are input through the keyboard and edited in accordance with error messages from the checking section of the set-up module, and a run-time module in which the instructions are carried out by the computer outputting appropriate control signals to the guide bar actuators. In the run-time mode, the computer operates the guide tars in synchronism with the other knitting elements by virtue of the shaft encoder 17 and also makes any adjustments necessitated by changes in machine speed if, for example, the actuators were subject to inertia effects.
The run-time module also controls inching and the position in which the machine stops, in order to minimise tension in the yarn and resulting forces on the knitting elements.
Other system variables such for example as oil pressure and temperature in the case of hydraulic actuators, back-up battery charge state, and guide-bar drift, can be monitored and compared to nominal values in the computer and warning or corrective action taken in off-limits situations.
Keyboard input can also operate the machine in a "manual" mode for setting up initial guide bar positions--it would be desirable to provide fractional needle adjustments for this purpose--and also for adjusting guide bars for maintenance purposes.
Instead of a computer being permanently connected to a knitting machine, it would be possible to set up and edit a suitable program on a computer and then to store the resulting program in a memory device such as a disc or tape or a non-volatile RAM or EPROM for insertion into a microprocessor connected to the machine. In this way, a central computer can be used for creating programs without having also to execute them. On the other hand a computer of sufficient capacity could handle the task of program creation and also control the operation of several knitting machines simultaneously.
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A method for operating the guide bars of warp knitting machines comprises feeding in to a computer desired lapping instructions, the computer being programmed to discriminate between permitted and prohibited lapping movements and being operative to prevent the attempted execution of prohibited movements. The computer can be programmed to test instructions against a set of mandatory rules, which proscribe lapping movements that would crash the guide bars, and may also be programmed to discriminate against ineffective lapping movements.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to data transfers in multiprocessor computing systems, and, more particularly, to a method and apparatus for supporting concurrent system area network inter-process communication and input/output (“I/O”).
2. Description of the Related Art
Even as the power of computers continues to increase, so does the demand for ever greater computational power. In digital computing's early days, a single computer comprising a single central processing unit (“CPU”) executed a single program. Programming languages, even those in wide use today, were designed in this era, and generally specify the behavior of only a single “thread” of computational instructions. Computer engineers eventually realized that many large, complex programs typically could be broken into pieces that could be executed independently of each other under certain circumstances. This meant they could be executed simultaneously, or “in parallel.” Thus, a computing technique known as parallel computing arose. Parallel computing typically involves breaking a program into several independent pieces, or “threads,” that are executed independently on separate CPUs. Parallel computing is sometimes therefore referred to as “multiprocessing” since multiple processors are used. By allowing many different processors to execute different processes or threads of a given application program simultaneously, the execution speed of that application program may be greatly increased.
In the most general sense, multiprocessing is defined as the use of multiple processors to perform computing tasks. The term could apply to a set of networked computers in different locations, or to a single system containing several processors. However, the term is most often used to describe an architecture where two or more linked processors are contained in a single enclosure. Further, multiprocessing does not occur just because multiple processors are present. For example, having a stack of PCs in a rack serving different tasks, is not multiprocessing. Similarly, a server with one or more “standby” processors is not multiprocessing, either. The term “multiprocessing”, therefore, applies only when two or more processors are working in a cooperative fashion on a task or set of tasks.
In theory, the performance of a multiprocessing system could be improved by simply increasing the number of processors in the multi-processing system. In reality, the continued addition of processors past a certain saturation point serves merely to increase communication bottlenecks and thereby limit the overall performance of the system. Thus, although conceptually simple, the implementation of a parallel computing system is in fact very complicated, involving tradeoffs among single-processor performance, processor-to-processor communication performance, ease of application programming, and managing costs. Conventionally, a multiprocessing system is a computer system that has more than one processor, and that is typically designed for high-end workstations or file server usage. Such a system may include a high-performance bus, huge quantities of error-correcting memory, redundant array of inexpensive disk (“RAID”) drive systems, advanced system architectures that reduce bottlenecks, and redundant features such as multiple power supplies.
There are many variations on the basic theme of multiprocessing. In general, the differences are related to how independently the various processors operate and how the workload among these processors is distributed. Two common multiprocessing techniques are symmetric multiprocessing systems (“SMP”) and distributed memory systems. One characteristic distinguishing the two lies in the use of memory. In an SMP system, at least some portion of the high-speed electronic memory may be accessed, i.e., shared, by all the CPUs in the system. In a distributed memory system, none of the electronic memory is shared among the processors. In other words, each processor has direct access only to its own associated fast electronic memory, and must make requests to access memory associated with any other processor using some kind of electronic interconnection scheme involving the use of a software protocol. There are also some “hybrid” multiprocessing systems that try to take advantage of both SMP and distributed memory systems.
SMPs can be much faster, but at higher cost, and cannot practically be built to contain more than a modest number of CPUs, e.g., a few tens. Distributed memory systems can be cheaper, and scaled arbitrarily, but the program performance can be severely limited by the performance of the interconnect employed, since it (for example, Ethernet) can be several orders of magnitude slower than access to local memory.) Hybrid systems are the fastest overall multiprocessor systems available on the market currently. Consequently, the problem of how to expose the maximum available performance to the applications programmer is an interesting and challenging exercise. This problem is exacerbated by the fact that most parallel programming applications are developed for either pure SMP systems, exploiting, for example, the “OpenMP” (“OMP”) programming model, or for pure distributed memory systems, for example, the Message Passing Interface (“MPI”) programming model.
However, even hybrid multiprocessing systems have drawbacks and one significant drawback lies in bottlenecks encountered in retrieving data. In a hybrid system, multiple CPUs are usually grouped, or “clustered,” into nodes. These nodes are referred to as SMP nodes. Each SMP node includes some private memory for the CPUs in that node. The shared memory is distributed across the SMP nodes, with each SMP node including at least some of the shared memory. The shared memory within a particular node is “local” to the CPUs within that node and “remote” to the CPUs in the other nodes. Because of the hardware involved and the way it operates, data transfer between a CPU and the local memory can be 10 to 100 times faster than the data transfer rates between the CPU and the remote memory.
Thus, a clustered environment consists of a variety of components like servers, disks, tapes drives etc., integrated into a system wide architecture via System Area Network (“SAN”) Fabric. A SAN architecture employs a switched interconnection (e.g., ServerNet or InfiniBand) between multiple SMPs. A typical application of a SAN is the clustering of servers for high performance distributed computing. Exemplary switched interconnections include, but are not limited to, ServerNet and InfiniBand, a technical specification promulgated by the InfiniBand Trade Organization.
Currently, two types of data transfer are currently being used for moving data across various components of a cluster. The first called IPC, is mainly involved in providing inter-process communication by performing memory-to-memory transfers. More particularly, IPC is a capability supported by some operating systems that allows one process to communicate with another process. A process is, in this context, an executing program or task. In some instances, a process might be an individual thread. IPC also allows several applications to share the same data without interfering with one another. The second type of data transfer is involved with at least one I/O device e.g., inter-node memory-to-disk and disk-to-disk transfer of data.
FIG. 1 illustrates one physical architecture of a computing system 100 currently available to realize the three logical interconnections between two Nodes that may arise from device data transfers. Each node 110 is shown including only a single CPU 125 , but may include several CPUs 125 . The computing system 100 is a “hybrid” system exhibiting characteristics of both SMP and distributed memory systems. Each node 110 includes shared memory 115 , provided by the shared disk(s) 120 , accessible by all the CPUs 125 in the computing system 100 and private memory 130 , provided by the private disks 135 , for each individual CPU 125 .
The three types of logical interconnections for internodal data transfer are:
memory to memory, e.g., from the host memory 140 in one node 110 to the host memory 140 in the other node 110 ;
memory to disk, e.g., from the host memory 140 in one node 110 to a shared disk 120 or a private disk 135 in the other node 110 ; and
disk to disk, e.g. from a shared disk 120 or a private disk 135 in one node 110 to a shared disk 120 or a private disk 135 in the other node 110 .
As can be seen from FIG. 1, all three logical connections will occur over the peripheral component interconnect (“PCI”) buses 145 . Under the protocols defining the operation of the PCI bus 145 , each internodal data transfer will need to arbitrate with other computing resources for control of the PCI bus 145 . Furthermore, if the CPU 125 were to need access to other devices, e.g., the device 150 , sitting on the PCI bus 145 , it too would be required to arbitrate.
This quickly results in the PCI Bus 145 becoming a bottleneck for performance. The old approach represented in FIG. 1 suffers from the following drawbacks:
only memory-to-memory or disk-to-disk memory transfers are possible at any given time;
memory-to-memory transfer access speeds are limited to PCI speeds (assuming serial interconnect speeds ramp up);
access of memory would prevent access of other devices on the PCI bus by other devices;
peer-to-peer access would result in non-accessibility of other devices on both PCI buses (e.g., the PCI buses 145 , 155 ); and
allows only one inter-node transaction to occur at any given time. Hence, there is a need for a technique that will permit concurrent access for memory-to-memory transfers between nodes, memory to device transfers within a node and for memory-to-disk or disk-to-disk transfers between nodes.
The present invention is directed to resolving, or at least reducing, one or all of the problems mentioned above.
SUMMARY OF THE INVENTION
A new technique for transferring data between nodes of a clustered computing system is disclosed. In one aspect, the invention includes a cluster node comprising a system bus; a memory device; and an internodal interconnect. The internodal interconnect is electrically connected to the system bus and includes a remote connection port. The internodal interconnect is capable of transferring data from the memory device and through the remote connection port. In a second aspect, a the invention includes method for internodal data transfer in a clustered computing system. Each of at least two clusters includes an internodal interconnect electrically connected to a system bus and a memory device to the system bus. The method itself comprises requesting a data transfer and then transferring the requested data. The requested data is transferred from the memory device in a first cluster node to the memory device in a second cluster node via the internodal interconnects in the first and second cluster nodes.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
FIG. 1 illustrates conventional internodal data transfers in a prior art, clustered computing system;
FIG. 2 depicts, in a conceptualized block diagram, an cluster node constructed and performing internodal data transfers in accordance with the present invention;
FIG. 3A depicts, in a conceptualized block diagram, one particular embodiment of the cluster node in FIG. 2;
FIG. 3B depicts, in a conceptualized block diagram, a second particular embodiment of the cluster node in FIG. 2 alternative to that in FIG. 3A;
FIG. 4 illustrates internodal data transfers a clustered computing system architecture employing the embodiment of FIG. 3A of the cluster node in FIG. 2;
FIG. 5 illustrates internodal data transfers a clustered computing system architecture employing the embodiment of FIG. 3B of the cluster node in FIG. 2; and
FIG. 6 illustrates internodal data transfers in embodiment alternative to those set forth above.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort, even if complex and time-consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
FIG. 2 depicts, in a conceptualized block diagram, a cluster node 200 constructed and configured to perform internodal data transfers in accordance with the present invention. The cluster node 200 comprises, in the illustrated embodiment, a system bus 210 , an I/O bus 220 , a memory device 230 , and an internodal interconnect 240 . The internodal interconnect 240 is capable of receiving data from local memory and commands over the system bus 210 and the I/O bus 220 . The internodal interconnect 240 is also capable of receiving data from remote memory and commands over a remote connection 250 .
The system bus 210 and the I/O bus 220 may operate in accordance with any suitable protocol known to the art. As will be appreciated by those in the art, the operation of the system bus 210 will be dictated to a large degree by the implementation of the CPU (not shown) residing on the system bus 210 . The system bus 210 might, for example, be an X86 bus (such as a Pentium III™ or a Pentium Pro™ bus), although alternative embodiments might be implemented differently. Similarly, the I/O bus 220 might be implemented using a variety of protocols, e.g., a peripheral component interface (“PCI”) bus or a PCI-X bus. Another technology that might be used in implementing the I/O bus 220 is known as “I2O”. The I2O protocol is designed to work with the PCI bus. In the I2O protocol, specialized I/O processors (not shown) are used to handle certain aspects of the bus' implementation, e.g., interrupt handling, buffering, and data transfer. The I/O processors operate under an I2O driver, or operating system (“OS”) module (“OSM”) that handles higher level OS-type details through a specialized hardware device module (“HDM”). The OSM and HDM operate at the OS level, and function autonomously to handle transactions on the I/O bus, e.g., the I/O bus 220 .
The memory device 230 is shown residing on the I/O bus 220 . However, in alternative embodiments the memory device 230 might reside on the system bus 210 . In still other alternative embodiments, a first memory device 230 might reside on the I/O bus 230 while a second memory device 230 resides on the system bus 210 . The invention admits wide variation in the implementation of the memory device 230 . The memory device 230 may be any type of memory device known to that art, and may be electrical, magnetic, or optical in nature. Thus, the memory device 230 might be implemented in, for example, a dynamic random access memory (“DRAM”) device, an optical disk (e.g., a compact-disk read only memory, or “CD ROM”), or a magnetic disk (e.g., a hard drive disk). Other technologies may also be used. The memory device 230 may also comprise a portion of a host memory, a private memory, or a shared memory, depending upon the implementation. In the illustrated embodiment, the memory device 230 is a magnetic disk comprising a portion of a private or a shared memory.
Thus, in a more general sense, the internodal interconnect 240 is electrically connected between the system bus 210 and the I/O bus 220 and communicates with a memory device, e.g., the memory device 230 , over one of the system bus 210 and the I/O bus 220 . Note that the internodal interconnect 240 might therefore be employed in local data transfers as well as internodal transfers. Although the primary benefits of the present invention are more fully appreciated in the context of internodal data transfers, design constraints might make using the internodal interconnect 240 in local data transfers desirable in some implementations.
The invention also admits variation in the implementation of the internodal interconnect 240 . FIG. 3A depicts, in a conceptualized block diagram, one particular embodiment 300 of the cluster node 200 in FIG. 2 . In this particular embodiment, a “System Area Network Chip” 305 provides a single-chip implementation of the internodal interconnect 240 . FIG. 3B depicts, in a conceptualized block diagram, a second particular embodiment 350 of the cluster node 200 in FIG. 2 as an alternative to that in FIG. 3 A. In this particular embodiment, a network engine, e.g., ServerNet network engine, interconnection 355 provides another implementation of the internodal interconnect 240 . Still other embodiments might be realized using alternative implementations.
Turning now to FIG. 3A, the System Area Network Chip 305 is a modified Host Bridge connected to both a System Bus 310 and an I/O bus 315 . The chip 305 is a peer to the Host bridge 320 and the I/O Bridge 325 . The chip 305 is produced by modifying a conventional host bridge to embed a conventional ServerNet engine therein. Note that this particular embodiment includes both a host memory 330 residing on the system bus 310 and a disk memory 335 residing on the I/O bus 315 . The disk memory 335 may be either a private memory or a shared memory. Thus, the embodiment 300 may be used to implement the invention in memory to memory transfers, memory to disk transfers, and disk to disk transfers, both internodal and local.
FIG. 3B depicts an embodiment 350 in which the internodal interconnect 240 is implemented as a ServerNet chip 355 . The ServerNet chip 355 is a part of the ServerNet Interconnect Technology commercially available from Compaq Computer Corp., the assignee of this application, who can be contacted at:
P.O. Box 692000
Houston, Tex. 77269-2000
Ph: 281-370-0670
Fax: 281-514-1740
<www.compaq.com>
Technical information regarding the ServerNet product is available at the numbers listed above and on the website.
Generally, ServerNet technology enables scalable I/O bandwidth such that, when a server is expanded, more data paths are added, and the aggregate bandwidth of the ServerNet interconnect increases. ServerNet technology does this by embedding a reliable network transport layer into a single very large scale integration (“VLSI”) integrated circuit (“IC”) hardware device to connect a processor or I/O device to a scalable interconnect fabric composed of as many very high-speed point-to-point data paths, as needed. Each high-speed path uses a hardware protocol to guarantee delivery of data between devices. The data paths allow system elements (processors, storage, I/O) to be joined into a system area network. Data paths from system elements are connected together within the system area network by means of six-port routers (not shown), which are single VLSI devices that use switching technology to direct requests to the correct data path. Using these routers, the system elements are assembled into as large a server as desired.
As in an ordinary computer network, any system element in a ServerNet configuration can communicate with any other element. While ServerNet can function as an interprocessor interconnect with both elements being processors, it also performs the role of connecting processors to I/O devices. ServerNet can also connect I/O devices directly to other I/O devices, so that data is transferred without requiring a trip through a processor. Data-intensive applications running on a processor can steer transfers through the server by managing directions rather than by moving the data itself. This capability streamlines data transfers and frees the processor for other important tasks.
The ServerNet architecture avoids the latency of multiple-bus interconnections by using an interconnect network to deliver data directly from any processor or I/O device to any other processor or I/O device. This low latency per connection, achieved by VLSI hardware, allows one of the shortest message-delivery latencies of any processor interconnect technology available today. ServerNet technology can eliminate software latency through its unique “push/pull” ability to extract or deliver data autonomously to a node. Interconnect data transfers can themselves contain the addresses of information in other node(s) to “push” (write) data to or “pull” (read) data from. A node can then request subsequent transfers from another node without requiring software interaction from that node, as the node's ServerNet device performs the operation without disturbing its processor.
Returning to FIG. 3B, this particular embodiment implements the internodal interconnect 240 using a conventional ServerNet interconnection 355 configured within the node 350 as shown. More particularly, the ServerNet interconnection 355 is electrically interconnected between the system bus 360 and the I/O bus 365 . Note how this configuration differs from the conventional configuration show in FIG. 1 . Note that this particular embodiment also includes both a host memory 370 residing on the system bus 360 and a disk memory 375 residing on the I/O bus 365 . The disk memory 375 may be either a private memory or a shared memory. Thus, the embodiment 350 may also be used to implement the invention in memory to memory transfers, memory to disk transfers, and disk to disk transfers, both internodal and local.
FIG. 4 and FIG. 5 illustrate internodal data transfers in a clustered computing system architecture employing the embodiments of FIG. 3 A and of FIG. 3B, respectively, of the cluster node in FIG. 2 . Both the computing system 400 in FIG. 4 and the computing system 500 in FIG. 5 include two remote connections between the SMP nodes, i.e., the remote connections 405 , 410 in FIG. 4 and the remote connections 505 , 510 in FIG. 5 . The disk memory 335 in FIG. 3A is implemented in the shared memory 415 and the private memory 430 in FIG. 4 . The disk memory 375 in FIG. 3B has been implemented in the shared memory 515 and the private memory 530 .
Thus, the present invention comprises a faster, more efficient implementation of the three types of logical interconnections for internodal data transfer:
memory to memory, e.g., from the host memory 330 , 370 in one node 300 a , 350 a to the host memory 330 , 370 in the other node 300 b , 350 b;
memory to disk, e.g., from the host memory 330 , 370 in one node 300 a , 350 a to a shared disk 435 , 535 or a private disk 420 , 520 in the other node 300 b , 350 b ; and
disk to disk, e.g., from a shared disk 435 , 535 or a private disk 420 , 520 in one node 300 a , 350 a to a shared disk 435 , 535 or a private disk 420 , 520 in the other node 300 b , 350 b.
As can be seen from the drawings, especially FIG. 4 and FIG. 5, memory to memory access between two nodes can occur concurrently with disk-to-disk transfers. This is because the former is first accomplished over the system bus 310 , 360 while the latter occurs over the I/O bus 315 , 365 . As disk transfers are slower than memory transfers, IPC type data transfers from memory-to-memory will not experience the bottleneck or latencies associated with the I/O bus. Note that the internodal interconnect is theoretically capable of matching the data access rates of both the system bus and the I/O bus. Therefore, with the present invention, internodal data transfers will be limited primarily by the speed of the internodal interconnect.
Note that, although the embodiments of FIG. 4 and FIG. 5 show data transfer between nodes that are similar in structure and function, this is not necessary to the practice of the invention. FIG. 6 illustrates internodal data transfers in such an embodiment alternative to those set forth above. In FIG. 6, the computing system 600 comprises a node 605 similar in structure and operation to the nodes in FIG. 4 and FIG. 5 . However, the computing system 600 also includes a “memory farm” 615 , which may be considered a node dedicated to storage, e.g., host memory. The node 605 is subject to all the variation in the nodes illustrated in the preceding embodiments, and the node 615 may be implemented in any manner known to the art. Both the nodes 605 , 615 , however, include an internodal interconnect 640 that may be, e.g., a SAN chip or a ServerNet connection. The memory farm 615 , in the illustrated embodiment, includes a memory device 630 resident on the system bus 610 that may be part of a larger memory storage. Note that the memory farm 615 does not include an I/O bus. Memory transfers may occur between the memory devices 635 , 630 in the node 605 and the memory device 630 of the memory 615 in a manner analogous to that described above for the computing systems 400 , 500 in FIG. 4 and FIG. 5 .
Furthermore, in the various illustrated embodiments and aspects of the invention, the invention yields one or more of the following advantages:
connection to the I/O bus as well as the system bus provides concurrent memory-to-memory and disk-to-disk or memory accesses;
memory to memory transfer could occur at system bus speeds;
SAN access of memory does not prevent access of other devices on the I/O bus;
capability for accessing data on either of the I/O buses; and
connecting to the system bus enables split transaction capabilities.
However, the particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.
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A new technique for transferring data between nodes of a clustered computing system is disclosed. In one aspect, the invention includes a cluster node comprising a system bus; a memory device; and an internodal interconnect. The internodal interconnect is electrically connected to the system bus and includes a remote connection port. The internodal interconnect is capable of transferring data from the memory device and through the remote connection port. In a second aspect, a the invention includes method for internodal data transfer in a clustered computing system. Each of at least two clusters includes an internodal interconnect electrically connected to a system bus and a memory device to the system bus. The method itself comprises requesting a data transfer and then transferring the requested data. The requested data is transferred from the memory device in a first cluster node to the memory device in a second cluster node via the internodal interconnects in the first and second cluster nodes.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent application having U.S. Ser. No. 11/338,117, filed in the U.S. on Jan. 23, 2006 and published as Pre-Grant Publication 2006/0264370, which application claims priority under 35 U.S.C. 119(a) to Chinese Patent Application No. 2005100202199, filed on Jan. 21, 2005, which applications are both incorporated herein by specific reference in their entirety.
BACKGROUND
[0002] Fungus is opportunistic pathogens in humans. Fungus typically does not infect healthy tissues, yet once tissue defense mechanisms have been compromised, they can readily infect the tissue. One typical model of this opportunistic fungal infection is candidiasis, which is caused by Candida albicans.
[0003] Candida albicans occurs as normal flora in the oral cavity, genitalia, large intestine, and skin of approximately 20% of humans. The risk of infection increases in children and pregnant women; people who use certain antibiotics or have nutritional and organic disease or immunodeficiency (e.g., AIDS) or trauma; and people with invasive devices, e.g., pacemakers. Candida albicans and its close relatives account for nearly 80% of nosocomial fungal infections and 30% of deaths from nosocomial infections in general.
[0004] Historically, opportunistic fungal infections in hospitalized patients were rather unusual. Textbooks from the past described these agents as common contaminants with weak pathogenic potential, and infections were considered extreme deviation from the normal. Older ideas concerning these so-called harmless contaminants are now challenged because in those days immunodeficient and debilitated patients had died from their afflictions long before fungal infection took place. However, currently, with the advent of innovative surgeries, drugs, and other therapies that maintain such patients for expected periods, the survival rates of patients have significantly increased and the number of compromised patients has thus increased. One clinical dilemma that cannot be completely eliminated, even with rigorous disinfections, is the exposure of such patients to potential fungal pathogens from even normal flora. Fungal infections in such high-risk patients progress rapidly and are difficult to diagnose and treat. In one study, fungi caused approximately 40% of the deaths from clinically acquired infections. Up to 5% of all nosocomial opportunistic fungi cause infections.
[0005] Fungi also present special problems in chemotherapy. A majority of chemotherapeutic drugs used in treating bacterial infection are generally ineffective in combating fungal infection. Moreover, the similarity between fungal and human cells often means drug toxic to fungal cells are capable of harming human cells. A few drugs with special antifungal properties have been developed for treatment of systemic and superficial fungal infections. For example, macrolide polyenes represented by amphotericin B, have a structure that mimics some cell membrane lipids. Amphotericin B which is isolated from a species of streptomycin is by far the most versatile and effective of all antifungal drugs. The azoles are broad-spectrum antifungal drugs with a complex ringed structure. As one of the most effective azole drugs, fluconazole, is used in patients with AIDS-related mycoses.
[0006] Magnaporthe grisea is the pathogen of a devastating fungal disease of rice plants known as rice blast. The fungus can also cause a similar disease in over 50 grasses, including economically important crops such as barley, wheat, and millet. Fusarium is another important genus of fungal pathogens, responsible for devastating diseases such as cereal scab.
SUMMARY
[0007] The present invention is directed to novel nucleic acid molecules encoding for peptides that include a fungi specific targeting agent, e.g., a pathogenic fungal peptide pheromone, and a channel-forming colicin or a channel-forming fragment thereof (also referred to herein as “domain”). Peptides comprising a pheromone as the fungi specific targeting agent, and a colicin domain, are referred to herein as “pheromonicin peptides”.
[0008] The molecular structure of the formed peptides may have the C-terminus of colicin or a channel-forming domain linked with the N-terminus of a fungi specific targeting agent, e.g., a fungal pheromone, or the N-terminus of colicin may be linked with the C-terminus of a fungi specific targeting agent e.g., a fungal pheromone. The fungal pheromone can be from a pathogenic fungus, e.g., Candidas . The molecular weight of the peptide may vary, e.g., from about 26,000 to about 70,000 daltons.
[0009] The nucleic acid molecules of the present invention may be formed by a variety of methods. One method of forming a peptide of the present invention is by inserting a nucleic acid molecule encoding a fungal pheromone into a selected position of a nucleic acid molecule encoding a colicin, or a channel forming domain thereof, then transfecting the mutant plasmid into a host cell, e.g., E. coli , to produce the peptide.
[0010] In one embodiment, the peptides encoded by the nucleic acid molecules of the present invention are useful in treating infections of Candidas or Aspergillus or Magnaporthes or Fusarium . Exemplary infections are those created by Candida albicans, Candida tropicalis, Candida parapsilokis, Candida krusei, Candida dubliniensis, Cryptococcus neoformans, A. fumigatus, A. flavus, A. niger, Magnaporthe grisea and Fusarium moniforme.
[0011] The invention further provides vectors having the nucleic acid molecules that encode the peptides of the invention. The invention also provides cells, e.g., host cells, comprising the vectors of the invention.
[0012] Host cells, including bacterial cells such as E. coli , insect cells, yeast or mammalian cells (such as Chinese hamster ovary cells (CHO) or COS cells), can be used to produce the peptides of the invention. Other suitable host cells are known to those skilled in the art. The invention thus provides methods for producing the peptides of the invention comprising the steps of culturing the host cells of the invention and isolating the peptides of the invention therefrom.
[0013] In another embodiment, the invention provides a method for preparing a peptide which inhibits growth of a fungus comprising: (i) inserting a nucleic acid molecule encoding colicin, or a channel forming domain thereof, into a selected position of a nucleic acid molecule encoding a fungal targeting agent, e.g., a pheromone; (ii) transfecting the mutant plasmid into a host cell, e.g., an E. coli cell; and (iii) allowing said host cell to produce said peptide. In further embodiments, the peptide may be purified from the cells.
[0014] In another embodiment, the invention provides a method for preparing a fusion peptide comprising: (i) incorporating a nucleic acid molecule encoding the peptide chain of colicin Ia with a nucleic acid molecule encoding a fungal pheromone such as Candida albicans alpha-mating pheromone; and (ii) introducing said nucleic acid molecule encoding the peptide chain of colicin Ia incorporated with said fungal pheromone a following the C-terminus of the colicin Ia to form a nucleic acid molecule that encodes a 639 residue peptide.
[0015] In another embodiment, the invention provides a method for preparing a fusion peptide comprising: (i) incorporating a nucleic acid molecule encoding a peptide chain of colicin Ia with a nucleic acid molecule encoding a fungal pheromone such as Candida albicans alpha-mating pheromone; and (ii) introducing said nucleic acid molecule before the N-terminus of said colicin Ia to form a nucleic acid molecule that encodes a 639 residue peptide.
[0016] In one embodiment, the invention provides a method of treating a subject having a fungal infection comprising: administering to a subject a therapeutically effective amount of a fusion peptide of the present invention, e.g., a peptide comprising a colicin Ia with a fungal targeting agent, e.g., a pheromone. Said subject may have a Candidas or Aspergillus or Magnaporthe or Fusarium infection. Specifically, Candidas or Aspergillus or Magnaporthe or Fusarium may be selected from the group consisting of Candida albicans, Candida tropicalis, Candida parapsilokis, Candida krusei, Candida dubliniensis, Cryptococcus neoformans, A. fumigatus, A. flavus, A. niger, Magnaporthe grisea and Fusarium moniforme . The peptides of the instant invention can also be used to treat clinical fugal infections and other fungal infections in crops.
[0017] The peptides of the invention can be incorporated into pharmaceutical compositions suitable for administration to a subject. In a preferred embodiment, the pharmaceutical composition comprises a peptide of the invention comprising the C. albicans alpha-pheromone and a pharmaceutically acceptable carrier.
[0018] The term, “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like that are physiologically compatible. Preferably, the carrier is suitable for intravenous, intramuscular, subcutaneous or parenteral administration (e.g., by injection). Depending on the route of administration, the active compound may be coated in a material to protect the compound from the action of acids and other natural conditions, which may inactivate the compound.
[0019] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0020] The foregoing and following information as well as other features of this disclosure 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 several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which:
[0021] FIG. 1 schematically depicts the structure of a recombinant plasmid that contains the gene of colicin Ia with the gene of Candida albicans alpha-mating pheromone inserted following the C-terminus of colicin Ia in the plasmid pET-15b to form a plasmid referred to herein as pCHCCA1.
[0022] FIG. 2 schematically depicts the structure of a recombinant plasmid that contains the gene of colicin Ia with the gene of Candida albicans alpha-mating pheromone inserted following the N-terminus of colicin Ia in the plasmid pET-15b to form the plasmid referred to herein as pCHCCA2.
[0023] FIG. 3 depicts a growth inhibition assay wherein ATCC 10231 C. albicans cells were grown in M-H solid medium and exposed to (A) borate stock solution as control, (B) 50 ul amphotericin B (1 ug/ml), (C) 50 ul fluconazole (3 ug/ml), (D) 50 ul pheromonicin-SA (Ph-SA)(50 ug/ml), the fusion peptide against Staphylococcus aureus and (E) 50 ul pheromonicin-CA1 (Ph-CA1)(50 u/ml), the peptide produced by the pCHCCA1 plasmid.
[0024] FIG. 4 depicts the inhibition effects of Ph-CA against the growth of ATCC 10231 C. albicans cells in M-H liquid medium. The amount of sedimentary fungal filaments at the bottom of flasks indicated the inhibition effects of treatment agents. (A) Control, (B) fluconazole, (C) amphotericin B, (D) Ph-SA, (E) Ph-CA2 produced by pCHCCA2 plasmid and (F) Ph-CA1.
[0025] FIG. 5 depicts the inhibition effects of Ph-CA against the growth of C. albicans cells in liquid medium. The amount of spores and filaments of ATCC 10231 C. albicans cells indicated the inhibition effects. (A) Control, (B) fluconazole, (C) amphotericin B, (D) Ph-SA, (E) Ph-CA2 (F) Ph-CA1. X400.
[0026] FIG. 6 depicts the fluorescent imaging of ATCC 10231 C. albicans cells treated by Ph-CA1 and stained with 50 nM FITC/600 nM propidium iodide. (A) Control, cells were stained by FITC as green, (B) cells became red after 24 hrs Ph-CA1 treatment (10 ug/ml). X400.
[0027] FIG. 7 depicts a growth inhibition assay wherein Huaxi 30168 Cryptococcus neoformans cells were grown in M-H solid medium and exposed to (A) and (B) 100 ul amphotericin B (2 ug and 0.5 ug/ml respectively), (C) and (D) 100 ul Ph-CA1 (50 ug and 25 ug/ml respectively).
[0028] FIG. 8 depicts a growth inhibition assay wherein Huaxi 30255 Aspergillus flavus cells were grown in PDA solid medium and exposed to (A), (B) and (C) 100 ul tricyclazole (5 mg, 0.5 mg, and 0.05 mg/ml respectively), (D) 100 ul Ph-CA1 (50 ug/ml).
[0029] FIG. 9 depicts a growth inhibition assay wherein ACCC 30320 Magnaporthe grisea cells were grown in PDA solid medium and exposed to (A) 100 ul amphotericin B (0.5 ug/ml), (B) 100 ul tricyclazole (0.5 mg/ml), (C) and (D) 100 ul Ph-CA1 (25 ug and 50 ug/ml respectively).
[0030] FIG. 10 depicts a growth inhibition assay wherein ACCC 30133 Fusarium moniforme cells were grown in PDA solid medium and exposed to (A) control, (B) 100 ul amphotericin B (0.5 ug/ml), (C) Ph-CA1 100 ul Ph-CA1 (50 ug/ml) and (D) 100 ul tricyclazole (0.5 mg/ml).
[0031] FIG. 11 depicts in vivo activity of Ph-CA1 against systemic candidiasis. The C. albicans infected mice were untreated or treated by intraperitoneal amphotericin B or Ph-CA1.
[0032] FIG. 12 depicts in vivo activity of Ph-CA1 against systemic candidiasis. The C. albicans infected mice were untreated or treated by intravenous amphotericin B or Ph-CA1.
[0033] FIG. 13 depicts the microscopic view of visceral organs of mice treated with Ph-CA1 30 days. (A) liver, (B) kidney and (C) spleen stained with hematoxylin and eosin. 100X.
[0034] All arranged in accordance with at least one of the embodiments described herein, and which arrangement may be modified in accordance with the disclosure provided herein by one of ordinary skill in the art.
DETAILED DESCRIPTION
[0035] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.
[0036] The antifungal peptides of the present invention comprise a fungi specific targeting agent e.g., a fungal pheromone, and one or more channel-forming colicins or channel-forming domains thereof. The molecular structure is generally either the C-terminus of a colicin or channel-forming domain thereof, linked with the N-terminus of the fungal specific targeting agent, or the N-terminus of the colicin or channel forming domain thereof, linked with the C-terminus of a fungal specific targeting agent. Although full-length colicin may be used in the methods and compositions of the invention, in some embodiments, only a channel-forming domain is used. In a preferred embodiment, the colicin channel-forming domain consists essentially of amino acids 451-626 of colicin Ia.
[0037] Colicins are protein toxins produced by strains of E. coli . They are generally classified into groups corresponding to the outer membrane receptor on sensitive E. coli cells to which they bind, with colicins that bind to the BtuB protein, the high affinity receptor for vitamin B12, being known as the E group. E-type colicins are about 60 kDa proteins that have three functional domains each implicated in one of the three stages of cell killing. The C-terminal domain carries the cytotoxic activity, the central domain carries the receptor-binding activity, and the N-terminal domain mediates translocation of the cytotoxic domain across the outer membrane. Three cytotoxic activities are found amongst E-type colicins: (i) a pore-forming ion channel that depolarizes, the inner membrane (colicin E1); (ii) an H—N—H endonuclease activity that degrades chromosomal DNA (colicins E2, E7, E8 and E9); and (iii) ribonuclease activities (colicin E3, E4, E5 and E6). Colicin-producing bacteria are resistant against the action of their own colicin through possession of a small immunity protein that inactivates the cytotoxic domain. After binding to E. coli cell surface receptors, E-type colicins are translocated to their site of action by a tol dependent translocation system.
[0038] The peptides of the present invention maybe prepared by inserting a nucleic acid molecule encoding a fungal pheromone into the selected position of a nucleic acid molecule encoding a colicin, or a channel forming fragment thereof. The resulting transfected mutant plasmid may then inserted into a host cell, e.g., E. coli , to produce the peptide. Colicin Ia has the nucleic acid sequence set forth in SEQ ID NO: 1. Candida albicans alpha-mating pheromone has the nucleic acid sequence set forth in SEQ ID NO:2 and the amino acid sequence set forth in SEQ ID NO:3.
[0039] The peptides of the invention may be used to treat subjects having a fungal infection, e.g., Candidas, Cryptococcus, Aspergillus, Magnaporthes or Fusariums . Exemplary fungal infections are oral thrush, oesophageal thrush (Oesophagitis), cutaneous (skin) candidiasis, vaginal yeast infection or candida vaginitis, balanitis, and systemic candidiasis. The peptides of the invention may also be used to treat devastating fungal infections in crops.
EXAMPLES
Example 1
[0040] A fusion peptide that has been identified as pheromonicin-CA1 (Ph-CA1) was created incorporating a peptide chain of colicin Ia with a Candida albicans alpha-mating pheromone, wherein the pheromone was c-terminal to the colicin Ia to produce a polynucleotide having the nucleic acid sequence of SEQ ID NO:4 which encodes a polypeptide having the amino acid sequence of SEQ ID NO:5.
Example 2
[0041] A second fusion peptide denominated as pheromonicin-CA2 (Ph-CA2) was created by incorporating a peptide chain of colicin Ia with a Candida albicans alpha-mating pheromone, wherein the pheromone is n-terminal to the colicin Ia, to produce a polynucleotide having nucleic acid sequence of SEQ ID NO:6 which encodes a polypeptide having the amino acid sequence of SEQ ID NO:7.
Results
[0042] Ph-CA1 had definite antifungal effect on Candida albicans (ATCC 10231) in vitro and in vivo. In contrast, Ph-CA2 almost had no effect. One in vitro cell growth inhibition assay was performed with M-H or PDA solid mediums. About 5 ul Cells (10 8 CFU/ml) of Candida albicans (ATCC 10231), Cryptococcus neoformans (Huaxi 30168 strain, clinical isolated strain by West China Hospital, Sichuan University), Aspergillus flavus (Huaxi 30255 strain), Magnaporthe grisea (ACCC 30320 strain, Species Conservation Center, Chinese Academy of Agriculture Sciences), or Fusarium moniforme (ACCC 30133 strain) were inoculated on the surface of 10 ml M-H or PDA solid mediums contained in disks. Then 50-100 ul amphotericin B (0.5 ug to 2 ug/ml) or fluconazole (3 ug/ml) or tricyclazole (0.05 mg to 5 mg/ml) or Ph-CA1 (25 to 50 ug/ml) either rinsed in a piece of filter paper or contained in a container then being placed on the surface of the medium, and incubated at 35° C. for 2 to 4 days.
[0043] As shown in FIG. 3 , only an inhibition-zone surrounds Ph-CA1, while no similar zones were observed with other agents. FIGS. 7 to 10 show that Ph-CA1 had definite antifungal effects against corresponding Cryptococcus neoformans, Aspergillus flavus, Magnaporthe grisea and Fusarium moniforme cells. On a molar basis, such antifungal effects were one hundred to one thousand times greater than that of known antifungal antibiotics.
[0044] In vitro cell growth inhibition assays were performed in 100 ml Klett flasks containing 10 ml of M-H medium which were monitored turbimetrically with a BioRad 550 microplate reader at OD595 nm every 60 min. The filament (mycelium) precipitation at the bottom of flask was counted with a digital photo-recorder every 6 hrs. Cells were inoculated to an initial cell density of about 2.5×10 5 CFU/ml and shaken at 200 rpm on an orbital shaker at 35° C. Sedimentary fungal filaments appeared in about 36 hrs growing.
[0045] Ph-CA1 and Ph-CA2 were added at the start of the culture. The same amount of borate stock solution (50 mM borate, PH9.0), Ph-SA (pheromonicin constructed by colicin Ia and staphylococcal pheromone AgrD1)(10 ug/ml) and several antibiotics preparations (2 ug/ml amphotericin B, 6 ug/ml fluconazole) were used as controls. All assays were expressed in turbidometric absorbance units measured at 595 nm and pictures of the filament sedimentation at the bottom of the flask were taken.
[0046] Fluconazole and Ph-SA had no effect on the growth of C. albicans compared to untreated controls. In contrast, 10 ug/ml Ph-CA1 completely inhibited C. albicans growth, as did 2 ug/ml amphotericin B. 10 ug/ml Ph-CA2 had about 30% of the inhibition effect as the Ph-CA1. Considering the difference in molecular weight between Ph-CA1 (70 kDa) and amphotericin B (about 0.9 kDa), the inhibitory effect of Ph-CA 1 against C. albicans was approximately ten times greater, on a molar basis, than that of amphotericin B (see FIG. 4 ). The spores and filaments of 2 ul treated medium were dripped on a slide and observed under microscope. In comparison with control and other treatments, spores were scarcely observed in the amphotericin B and Ph-CA1 (see FIG. 5 ).
[0047] FIG. 6 shows that after 24 hrs of incubation with Ph-CA1 (10 ug/ml), cell membrane of most C. albicans cells (stained by FITC as green in the presence of propidium iodide) was damaged thus the propidium iodide entered into the cell to stain cells red.
[0048] KungMing mice, half male and half female, weighing 18-22 g were injected intraperitoneally with 0.5 ml of C. albicans (ATCC 10231), 10 8 CFU/ml. One hour after C. albicans injection, mice were injected intraperitoneally with 0.9% saline (A) alone as control (n=10) (C), or with amphotericin B (n=10, 1 ug/gm/day) (B), or with Ph-CA1 (n=10, 5 ug/gm/day) (A) daily for 14 days. The number of surviving animals was determined every 24 hours ( FIG. 11 ).
[0049] KungMing mice, half male and half female, weighing 18-22 g were injected intraperitoneally with 0.7 ml of C. albicans (ATCC 10231), 10 8 CFU/ml. One hour after C. albicans injection, mice were injected in the tail vein with 0.9% saline alone as control (n=10) (C), or with amphotericin B (n=10, 1 ug/gm) (B), or with Ph-CA1 (n=10, 5 ug/gm) (A). The mice were then injected intraperitoneally with 0.9% saline alone, or with amphotericin B (n=10, 1 ug/gm), or with Ph-CA1 (n=10, 5 ug/gm) each day. The number of surviving animals was determined every 24 hours ( FIG. 12 ). Considering the difference in molecular weight between Ph-CA1 (70 kDa) and amphotericin B (about 0.9 kDa), the in vivo antifungal activity of Ph-CA1 against systemic candidiasis was at least twenty times greater, on a molar basis, than that of amphotericin B.
[0050] KungMing mice (n=10), half male and half female, weighing 18-22 g were injected intraperitoneally with Ph-CA1 (200 ug/mouse/day) for 20 days. The bodyweight of all mice was increased. There was no microscopic evidence of necrosis or inflammation in the livers, kidneys or spleens of mice ( FIG. 13 ).
[0051] A 300 m 2 rice field (seed, gangyou 725) with Magnaporthe grisea infection was randomly divided as three zones. The middle 100 m 2 area was treated with water spraying twice as control, the left 100 m 2 area was treated with tricyclazole spraying twice (0.5 mg/ml and 1 mg/ml) and the right 100 m 2 area was treated with Ph-CA1 spraying twice (1 ug/ml and 2 ug/ml) at the tillering stage. The time interval between two sprayings was 7 days. Each 200 leaves were randomly examined in control and treatment areas to determine the protecting efficacy of Ph-CA1. The data are depicted below in Table I.
[0000]
TABLE 1
Examining
Grades of impaired leaves
Incident
Infected
Protecting
date
0
1
3
5
7
9
rate
index
efficacy
One day
152
27
14
6
1
24
5.88
Before
Treatment
After
89
57
30
7
7
8
55.5
17.38
Treatment
Seven
172
10
12
6
14
4.22
75.83
days
Tri-
cyclazole
Ph-CA1
67
12
13
8
16.5
5.05
70.94
[0052] Another 300 m 2 rice field (seed, gangyou 725) with Magnaporthe grisea infection was randomly divided as three zones. The middle 100 m 2 area was treated with water spraying once as control, the left 100 m 2 area was treated tricyclazole spraying once (1 mg/ml) and the right 100 m 2 area was treated with Ph-CA 1 spraying once (2 ug/ml) at the head stage. About 200 ears were randomly examined in control and treatment areas to determine the protecting efficacy of Ph-CA1. The data are depicted below in Table II.
[0000]
TABLE II
Grades of impaired ears
Impaired
Infected
Damage
0
1
3
5
7
9
ears rate
index
rate
Control
178
33
22
11
2
2
28.6%
8.33
4.2%
Tri-
184
16
9
2
2
0
13.62%
3.5
1.63%
cyclazole
Ph-CA1
218
19
5
0
0
0
9.92%
1.56
0.53%
[0053] In both of the above in vivo protecting assays, the concentration of Ph-CA1 used was approximately 500 times smaller than that of tricyclazole. On a molar basis, the protecting effects of Ph-CA1 were three hundred times greater than that of tricyclazole. With these two factors taken together, the total effects of Ph-CA1 against rice blast disease was approximately 10 4 to 10 5 times greater than that of tricyclazole.
[0054] One skilled in the'art will appreciate that, for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments.
[0055] The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims.
[0056] The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited. to particular methods, reagents, compounds compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.
[0057] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
[0058] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or an (e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0059] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[0060] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.
[0061] From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims. All references recited herein are incorporated herein by specific reference in their entirety.
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The present invention is directed to nucleic acids encoding for fusion peptides comprising a fungal targeting agent and a channel-forming domain consisting essentially of amino acids 451-626 of colicin Ia, as well as vectors having the nucleic acids of the invention and host cells having the vectors. The fusion peptides of the peptides of the present invention are particularly useful for the treatment of fungal infections in a wide variety of organisms. The fusion peptides can be prepared from the nucleic acids, such as when a vector having the nucleic acid is included in a host cell.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor wafer processing and, more particularly, to desorption of one or more contaminants from a surface of a semiconductor wafer.
2. Description of Related Art
Semiconductor substrates, especially silicon wafers, can form a layer of surface contamination. This surface contamination is undesirable because it can adversely affect wafer processing and monitoring. This contamination comes from the local untreated atmosphere, which is typically a mixture of numerous gases and gaseous vapors. It is believed that these gases and vapors condensate on the surface of the wafer forming a liquid or semi-liquid film. Although the constituents of this contamination layer are not precisely known, it is believed that water is a primary component. The other contaminants are comprised mostly of various hydrocarbon molecules, which are collectively referred as organics.
One approach to removing the contamination layer is heating the wafer. Heretofore, heating a wafer has been accomplished by radiation or conduction. One radiation heating technique includes placing a wafer under a heating element and heating the topside of the wafer primarily through radiation. Practical radiation heating requires holding the heat source at temperatures significantly higher than the desired surface temperature. This heat can create undesirable temperature increases in the surrounding area which would necessitate additional thermal management techniques.
Since it is directly over the top surface of a wafer, a radiation heating element must be sealed and non-contaminating even at high temperatures. Sealing the element can reduce radiation effectiveness requiring even a higher temperature heat source. Materials that meet the non-contaminating requirements can also be expensive and hard to manufacture. An array of linear heating elements can create cool zones between the elements resulting in uneven heating of the wafer surface.
One conduction heating technique includes placing the wafer onto a heated surface, such as a hotplate. The wafer is then heated primarily through conduction from the backside of the wafer until the topside has reached a desired temperature. One problem with using a heating plate results from the use of robotic arms that transport the wafer by the backside thereof. Setting the wafer down onto the heated surface of the hotplate requires withdrawing of the robotic arm. A mechanical wafer lowering mechanism or a recessed pocket in the surface of the hotplate is usually required to accomplish this. A wafer lowering mechanism adds system complexity while a recessed pocket can create uneven wafer heating. Another problem with conduction heating is a possibility of contaminating the backside of the wafer by the hotplate itself.
It would, therefore, be desirable to provide an apparatus and method that avoids the foregoing problems, and others, while enabling the temperature of a semiconductor wafer to be raised sufficiently to facilitate desorption of contaminants thereon for subsequent testing thereof.
SUMMARY OF THE INVENTION
The invention is a method of desorbing one or more contaminants from a surface of a semiconductor wafer for measurement by a metrology tool. The method includes positioning a wafer in spaced parallel relation with the heating plate and heating the wafer by convection with gas heated by the heating plate for a predetermined time period to remove contaminants from the wafer surface. The wafer is then removed from spaced parallel relation with the heating plate and cooled by blowing a gas thereon. At least one characteristic of the wafer is measured with a metrology tool a predetermined time after wafer heating is complete.
The foregoing method can be repeated for a plurality of wafers. Each wafer can be positioned in spaced parallel relation between a pair of spaced parallel heating plates.
The invention is also a method of preparing a semiconductor wafer for measurement by a metrology tool. The method includes positioning the wafer in spaced parallel relation with a planar heating element and heating the wafer by convection with gas heated by the heating element for a predetermined heating time to remove contaminants from the wafer surface. The wafer is then removed from its spaced parallel relation with the heating plate and a stream of gas is caused to pass over a surface of the wafer for a predetermined cooling time thereby cooling the wafer. The wafer is then positioned in operative relation to a metrology tool and at least one characteristic of the wafer is measured with the metrology tool.
Lastly, the invention is a method of processing a semiconductor wafer. The method includes utilizing a heated gas to heat at least one part of a semiconductor wafer by convection whereupon at least one contaminant is desorbed therefrom. A stream of cooling gas is caused to pass over the one part of the semiconductor wafer in the absence of said heated gas to cool the one part of the semiconductor wafer. A metrology tool is then caused to measure the one part of the semiconductor wafer to determine at least one characteristic thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a system for desorbing and testing one or more semiconductor wafers;
FIG. 2 is a top view of the system shown in FIG. 1 ;
FIG. 3 is the system of FIG. 1 with the robotic arm assembly in a position for moving a desorbed semiconductor wafer through a stream of cooling gas; and
FIG. 4 is an isolated view of the desorption station of FIGS. 1 and 3 also or alternatively including a heated tube for delivering a heated gas to at least a portion of a semiconductor wafer.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with reference to the accompanying figures where like reference numbers correspond to like elements.
With reference to FIG. 1 , a system 2 for desorbing one or more contaminants from one or more surfaces of a semiconductor wafer includes a robotic arm assembly 4 for moving a semiconductor wafer 6 from an input/output station 8 to a desorption station 10 . Once semiconductor wafer 6 has been desorbed in response to convection heating of semiconductor wafer 6 by desorption station 10 , and semiconductor wafer 6 has been cooled to a suitable temperature for further testing, robotic arm assembly 4 transfers semiconductor wafer 6 to a metrology tool 12 for testing thereby. An exemplary metrology tool 12 can include a probe tip for contacting a surface of semiconductor wafer 6 and for applying a suitable electrical stimulus thereto. However, this is not to be construed as limiting the invention.
Examples of a suitable electrical stimulus include capacitance-voltage (CV), current-voltage (IV), conductance-voltage (GV) or capacitance-time (Ct) type electrical stimulus. Metrology tool 12 measures a response of semiconductor wafer 6 to the electrical stimulus and determines from the response at least one property of semiconductor wafer 6 at the point where the electrical stimulus is applied. Details regarding metrology tool 12 will not be described herein for simplicity of description. However, as will be appreciated by one of ordinary skill in the art, any suitable metrology tool 12 for determining a property of semiconductor wafer 6 can be utilized.
With reference to FIG. 2 and with continuing reference to FIG. 1 , input/output station 8 includes a base 14 for supporting a carrier 16 that is configured to carry one or more semiconductor wafers 6 . Base 14 can be configured to move carrier 16 upwardly or downwardly, as shown by arrow 18 in FIG. 1 , under the control of a controller 20 .
Robotic arm assembly 4 includes a base 24 coupled to a plurality of arms 26 a – 26 c . Base 24 can be configured to move arms 26 a – 26 c upwardly or downwardly as shown by arrow 28 in FIG. 1 . One end of arm 26 a is rotatably coupled to base 24 while the other end of arm 26 a is rotatably coupled to one end of arm 26 b . The other end of arm 26 b is rotatably coupled to one end of arm 26 c . Desirably, arm 26 c is in the form of a paddle having one or more vacuum holes 30 disposed therein adjacent the distal end thereof. Vacuum holes 30 are coupled to a source of vacuum (not shown) which can deliver a vacuum to vacuum holes 30 under the control of controller 20 . As shown in the figures, semiconductor wafer 6 can be disposed on the distal end of arm 26 c and held thereon by means of a vacuum supplied to vacuum holes 30 .
Desorption station 10 includes a circular heating plate 34 having a diameter that is desirably no less than the diameter of semiconductor wafer 6 . One desirable construction of heating plate 34 includes one or more thick film resistors formed on a circular ceramic substrate. Circular heating plates of this type are available from Watlow Electric Manufacturing Company, #6 Industrial Loop Road, P.O. Box 975, Hannibal, Mo., 63401, USA. However, this particular form of heating plate is not to be construed as limiting the invention.
Heating plate 34 is desirably spaced from a base of desorption station 10 by suitable standoffs 36 . Additionally, standoffs 38 are arranged on a top surface of heating plate 34 for maintaining semiconductor wafer 6 in spaced parallel relation to heating plate 34 during desorption of one or more contaminants from semiconductor wafer 6 . Standoffs 36 and 38 are desirably formed from a high-temperature glass-mica ceramic. However, this is not to be construed as limiting the invention since the use of any suitable high-temperature, non-contaminating material to form standoffs 36 and 38 is envisioned.
The height of each standoff 38 is selected whereupon the distal end of arm 26 c can position semiconductor wafer 6 thereon whereafter the source of vacuum to vacuum hole 30 can be terminated, The distal end of arm 26 c can then be moved from a position in contact with the backside of semiconductor wafer 6 to a position between semiconductor wafer 6 and circular heating plate 34 . Once in this position, the distal end of arm 26 c can be withdrawn from the space between semiconductor wafer 6 and heating plate 34 thereby facilitating heating of semiconductor wafer 6 by convection with gas heated by heating plate 34 .
Electrical current can be supplied to heating plate 34 under the control of controller 20 whereupon the temperature of heating plate 34 can be controlled. Suitable temperature sensing means (not shown) can be positioned on or adjacent heating plate 34 and coupled to controller 20 to enable controller 20 to detect and control the temperature of heating plate 34 . Also or alternatively, desorption station 10 can include a circular heating plate 40 , shown in phantom in FIG. 1 , disposed above standoffs 38 . Electrical current can be supplied to heating plate 40 under the control of controller 20 for controlling the temperature of heating plate 40 . Desirably, when heating plates 34 and 40 , are provided the spacing therebetween is sufficient to enable semiconductor wafer 6 and the distal end of arm 26 c to be received therebetween.
After semiconductor wafer 6 has been convection heated for a predetermined time period sufficient to desorb one or more contaminants from semiconductor wafer 6 , the distal end of arm 26 c can be reintroduced into the space between heating plate 34 and semiconductor wafer 6 under the control of controller 20 . Thereafter, robotic arm assembly 4 can be controlled to raise arm 26 into contact with the backside of semiconductor wafer 6 whereupon a vacuum can be applied to vacuum holes 30 to secure semiconductor wafer 6 to the distal end of arm 26 c . Robotic arm assembly 4 can then be controlled to lift semiconductor wafer 6 off standoffs 38 and to withdraw semiconductor wafer 6 from desorption station 10 .
With reference to FIG. 3 and with continuing reference to FIGS. 1 and 2 , robotic arm assembly 4 is then controlled to move semiconductor wafer 6 through a stream of gas 42 , desirably nitrogen, dispensed by a manifold 44 which receives said gas from a suitable gas source 46 .
In the illustrated embodiment, manifold 44 is coupled to a bottom side of desorption station 10 . However, this is not to be construed as limiting the invention since manifold 44 can be positioned at any convenient location accessible to robotic arm assembly 4 .
The rate that robotic arm assembly 4 moves semiconductor wafer 6 through stream of gas 42 is selected whereupon semiconductor wafer 6 is cooled sufficiently for testing by metrology tool 12 . To this end, if necessary, robotic arm assembly 4 can move semiconductor wafer 6 through stream of gas 42 a plurality of times. If desired, an on/off gas control valve (not shown) can be fluidly coupled to manifold 44 for on/off controlling stream of gas 42 under the control of controller 20 .
Once semiconductor wafer 6 has been cooled sufficiently, robotic arm assembly 4 is controlled to deliver semiconductor wafer 6 to metrology tool 12 for testing. Once semiconductor wafer 6 is in a proper position for testing by metrology tool 12 , controller 20 signals metrology tool 12 that testing of semiconductor wafer 6 can commence.
Desirably, metrology tool 12 commences testing semiconductor wafer 6 a predetermined time after convection heating of semiconductor wafer 6 by desorption station 10 is complete. By controlling the time between the end of convection heating of each semiconductor wafer 6 processed by desorption station 10 and the beginning of testing of said semiconductor wafer 6 with metrology tool 12 , variations in testing results between two or more wafers due to exposure to the atmosphere after desorption is avoided.
Once testing of semiconductor wafer 6 is complete, metrology tool 12 signals controller 20 . In response to receiving this signal from metrology tool 12 , controller 20 controls robotic arm assembly 4 to remove semiconductor wafer 6 from metrology tool 12 and to return semiconductor wafer 6 to the same location in carrier 16 from which it was initially obtained. Thereafter, the vertical position of base 14 and robotic arm assembly 4 can be controlled to deliver the next semiconductor wafer 6 supported in carrier 16 to desorption station 10 , stream of gas 42 and metrology tool 12 for testing and subsequent return to the same location in carrier 16 in the above-described manner. Desirably, the method of processing each semiconductor wafer 6 in carrier 16 continues until all of the semiconductor wafers 6 in carrier 16 have been processed in the above-described manner.
With specific reference to FIG. 2 , conventional atmospheric gas, i.e., atmospheric air, can be utilized for convection heating of semiconductor wafer 6 in desorption station 10 . However, if desired, semiconductor wafer 6 can be exposed to an atmosphere of a desirable gas, such as nitrogen, during desorption of semiconductor wafer 6 in desorption station 10 . To this end, desorption station 10 can include a manifold 48 for delivering the suitable gas to semiconductor wafer 6 received in desorption station 10 from a suitable source of said gas, e.g., gas source 46 .
In the above-described embodiment, heating plate 34 and/or heating plate 40 are described as having a diameter no less than the diameter of semiconductor wafer 6 . However, if desired, the diameter of heating plate 34 and/or heating plate 40 can be smaller than the diameter of semiconductor wafer 6 whereupon only a portion of semiconductor wafer 6 is heated by convection with gas heated by such smaller diameter heating plate(s).
With reference to FIG. 4 , also or alternatively, desorption station 10 can include a tube 50 for directing a stream of gas 52 from a gas source, e.g., gas source 46 , to at least one portion 54 of semiconductor wafer 6 . Tube 50 includes a heating element 56 which is coupled to a suitable source of electric power for heating tube 50 and, in turn, heating the gas flowing therethrough. Stream of gas 52 thus heated can heat portion 54 of semiconductor wafer 6 by convection. Tube 50 and heating element 56 are desirably configured to co-act whereupon the temperature of heated gas 52 is sufficient for desorbing at least one contaminant from portion 54 of semiconductor wafer 6 .
Once portion 54 of semiconductor wafer 6 has been desorbed, semiconductor wafer 6 can be exposed to a stream of cooling gas for cooling at least portion 54 thereof. This stream of cooling gas can be supplied to semiconductor wafer 6 via manifold 44 in the manner described above. Alternatively, the stream of cooling gas can be supplied via tube 50 simply by disconnecting heating element 54 from its source of electrical power whereupon stream of gas 52 which is no longer heated by heating element 56 can be utilized to cool portion 54 of semiconductor wafer 6 .
Once portion 52 of semiconductor wafer 6 is cooled sufficiently, semiconductor wafer 6 is delivered to metrology tool 12 for testing at least portion 54 thereof. Thereafter, semiconductor wafer 6 is removed from metrology tool 12 and returned to carrier 16 .
As can be seen, one or more contaminants on a surface of semiconductor wafer 6 can be desorbed in an efficient and predictable manner whereupon reliable testing of semiconductor wafer 6 by metrology tool 12 can be accomplished. The ability to heat the semiconductor wafer 6 by convection avoids possible contamination of the semiconductor wafer 6 resulting from contact between a heating element and semiconductor wafer 6 during conductive heating thereof and avoids the need for sealed radiation heating elements for radiation heating of semiconductor wafer 6 . Lastly, the ability to convectively heat a portion of semiconductor wafer 6 by blowing a heated gas thereon enables desorption of said portion while avoiding the need to heat the remainder of the semiconductor wafer 6 to a desorption temperature. Thereafter, the desorbed portion of semiconductor wafer 6 can be tested independently of the remainder of the semiconductor wafer 6 . It is envisioned that the ability to selectively heat one or more portions of a semiconductor wafer by convection will enable metrological testing of product semiconductor wafers utilizing conventional metrology tools.
The invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
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A method of processing a semiconductor wafer includes utilizing a heated gas to heat at least one part of a semiconductor wafer by convection whereupon at least one contaminant is desorbed therefrom. A stream of cooling gas is caused to pass over the one part of the semiconductor wafer in the absence of heated gas to cool the one part of the semiconductor wafer. A metrology tool is then caused to measure at least one part of the semiconductor wafer to determine at least one characteristic thereof.
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FIELD AND BACKGROUND OF THE INVENTION
[0001] Various methods and systems for synchronization of a cluster of devices (sometimes referred to as a cluster network or cluster system) and in particular for predictive synchronization of a cluster of multiple interconnected firewall devices are possible.
[0002] If a process is performed on a data packet and the process requires more time than the latency between packets in a data stream, then a bottleneck may occur, backing up data traffic and slowing data communication. One solution to such a bottleneck is to perform the function using a cluster of multiple devices sometimes referred to as a clustered network. In the cluster, a plurality of member devices simultaneously performs a process on a plurality of packets. As a packet arrives, a distributor directs the packet to an individual member device for processing (a single system may include multiple distributors). In sum, using parallel processing, the cluster of devices processes a large number of packets without slowing the data stream.
[0003] Firewall devices are often deployed in a clustered system. A firewall device inspects communication flows entering or leaving a trusted network and filters out unauthorized packets of data. For example, one popular firewall policy allows “solicited” Transmission Control Protocol (TCP) connections initiated from the protected network, but denies TCP “unsolicited” connections initiated from outside (e.g. the Internet). Another popular protocol is User Datagram Protocol (UDP) allows data to enter the protected network when solicited by a “SYN” packet. Both UDP and TCP are stateful protocols in which determining whether a data packet is a legitimate reply to a request from a member of the trusted network depends on state information. State information about a session or connection may be established in a firewall device when the first data packet sent from the trusted network initiating the connection is processed. Often state information used to identify a legitimate packet is associated with the packet header [for example all or part of the full TCP state, including source and destination addresses, Internet protocol (IP) addresses, ports and sequence numbers]. Different firewall implementations may have different header information.
[0004] When all communication is handled by a single firewall device, state information derived from the request packet may be stored locally to the firewall device for the lifetime of the session.
[0005] Often a single device cannot keep up with all the communication causing a communication bottleneck. One solution is to use a cluster of multiple firewall devices. Each device handles a portion of the communication traffic. In the firewall cluster, it is possible that a request packet may be handled by a first member firewall device and an associated response packet may be handled by a second member device. In order for the second member device to handle the response packet it must have access to state information stored in the first member firewall device, which handled the request packet. Thus, some firewall clusters share state information globally, for example by multicast broadcasting of state information to many or all of the member firewall devices. Global state information-sharing is complicated and does not scale well when the number of firewall devices in a cluster rises. Because many network connections are “short-lived,” processing power of firewall devices is wasted synchronizing state information.
[0006] A solution is to have a distributor that sends all packets of an established connection to the “home” firewall device in which the state information is kept locally. A conventional distributor sends a packet member to a cluster member designated by a deterministic hash function of the IP header information. This methodology allows a simple stateless distributor to consistently send packets of a single session having similar IP headers to a single cluster member. If all packets of each session are always sent to the same member firewall device, then there may be no need to share state information.
[0007] There are situations (for example an asynchronous session as illustrated herein below) where a stateless distributor based on a simple hash function may fail to direct all packets of a session to the same cluster member. Thus, a conventional firewall cluster with a stateless distributor may require sharing of state information in order to handle asynchronous sessions.
[0008] FIG. 1 illustrates an example of a cluster 10 of firewall devices handling an asynchronous session. A distributor 16 a is employed to load-balance traffic from the trusted network and a distributor 16 b is employed to load-balance traffic from the Internet.
[0009] Distributors 16 a and 16 b evenly distribute packets among three members 18 a, 18 b, and 18 c of cluster 10 for security processing. For example, a request packet is sent 20 a by a client 12 on a trusted network through distributer 16 a. The packet is intended for a server 14 on the Internet.
[0010] Distributor 16 a performs a deterministic hash of the relevant packet fields (e.g., the source address src-IP, and destination address dst-IP) to designate member 18 a to receive the request packet and distributor 16 a sends 20 b the request packet to member 18 a. Due to security considerations, member 18 a changes the packet header (for example by performing NAT [network address translation] or VPN encryption. Thus, the packet fields are now changed to a translated source address and the original destination address (trans-IP, dst-IP). Member 18 a sends 20 c the amended request packet to distributor 16 b and distributor 16 b sends 20 d the amended request packet to server 14 .
[0011] Server 14 sends 20 e a reply packet back to the translated source addresses of the modified header of the request packet (i.e., the reply packet has as the source and destination address, dst-IP and trans-IP respectively). The reply packet arrives to distributor 16 b, and distributor 16 b performs a hash using the same deterministic algorithm as distributor 16 a. Because the IP addresses of the reply packet differ from the IP addresses of the original request packet, distributor 16 b designates member 18 c to receive the reply packet (and not member 18 a, which received the original request packet) and sends 20 f the reply packet to member 18 c.
[0012] Thus, an asymmetric session has been created through firewall cluster 10 (the reply packet is handled by member 18 c, which did not handle the request packet). Member 18 c requires state information (for example member 18 c needs to know the IP header information of the request packet) in order to determine validity of the reply packet.
[0013] In general, in order to synchronize asymmetric flows between members, it is necessary to provide the required information for security processing (TCP state, TCP sequencing) In the conservative synchronization approach, information on all sessions through member 18 a is relayed 25 by a multicast broadcast to all other members 18 b - c in order that every member 18 a - c can handle the reply stream (it is necessary to send information to all members 18 b - c because it is not known, a priori, to which member 18 a - c the reply stream will be directed by distributor 16 b ). Based on information from the request packet, member 18 c verifies and sends 20 g the reply packet to distributor 16 a, and distributor 16 a sends 20 h the reply packet to client 12 .
[0014] As the cluster grows (having a large number of members to handle a large quantity of traffic quickly) communicating and duplicate storing of state information amongst a large number of cluster members will take up significant system resources. With increasing cluster size the increasing need for communication and data storage among members will significantly hurt performance scalability of the clustered system.
[0015] Various solutions have been proposed to solve the scalability problem of clustered systems handling asymmetric sessions. U.S. Pat. No. 7,107,609 to Cheng et al. teaches use of a multicast query to find the home member that owns a connection. The need for a query and reply every time a cluster member receives an unknown packet from the Internet may slow system performance and make the system prone to DoS attacks, where a large number of unknown packets overwhelm the system's ability to respond.
[0016] U.S. Pat. No. 7,401,355 to Supnik et al. teaches use of a single, stateful smart distributor for flow both from the Internet to the trusted network and from the trusted network to the Internet. Since the single distributor handles all flows, the distributor is aware of changes in IP address and always directs return traffic to the home cluster member that owns a session. As scale increases, the requirement of a single distributor that can statefully handle all flows may significantly increase the cost of the clustered system. Furthermore, the distributor may itself become a bottleneck, limiting system scalability and performance.
[0017] U.S. Pat. No. 7,613,822 to Joy, et al. describes a system where members of the cluster communicate with the distributor in order to send traffic to the home member of a session. The requirement of communication between the distributor and members makes necessary the use of a sophisticated custom distributor and the requirement that all cluster members communicate with the distributor may limit performance as the cluster scale increases.
[0018] Even in previous art clustered systems having a stateful distributor, which directs all packets of a particular session consistently to the same member, multiple copies of session state information are often sent to other members of the cluster in order to provide for backup. For example, if a home member of the cluster fails during a session, the distributor will send continuation of the session to a backup member. In previous art, the home member may not know which cluster member will be used as a backup for a given session. Therefore the home member may relay state information of the session to many other members so that each member is prepared to receive the session continuation in case of failure of the home member. The need for each member of a cluster to constantly update many other members of the cluster of the state of one or more sessions in order that each of the many members can serve as a backup member for any of the sessions results in major scaling problems.
[0019] There is thus a widely recognized need and it would be highly advantageous to have a cluster of stateful member devices that is scalable (can be enlarged without undue increase in communication between members) and that can handle backup and asymmetric sessions.
SUMMARY OF THE INVENTION
[0020] Various methods and systems for synchronization of clustered devices and in particular for synchronization of a unicast firewall cluster system are possible.
[0021] An embodiment of a method of synchronizing a clustered system having at least a first member and a second member may include the step of relaying from the first member to the second member information associated with a packet before arrival of the packet to the second member. The method may also include the step of predicting designation of the second member to receive the packet.
[0022] In an embodiment of a method of synchronizing a clustered system, the packet may be an asynchronous reply packet.
[0023] In an embodiment of a method of synchronizing a clustered system, the second member may be a backup member.
[0024] In an embodiment of a method of synchronizing a clustered system, the step of predicting may include computing a deterministic function.
[0025] In an embodiment of a method of synchronizing a clustered system, the step of predicting may include computing a hashing function.
[0026] An embodiment of a method of synchronizing a clustered system may also include the step of bouncing the packet from the second member to the first member.
[0027] In an embodiment of a method of synchronizing a clustered system, the step of relaying may be directed to the second member but not to a third member of the clustered system.
[0028] In an embodiment of a method of synchronizing a clustered system, the step of relaying may be by unicast communication.
[0029] In an embodiment of a method of synchronizing a clustered system, the step of relaying may be subsequent to the step of predicting.
[0030] An embodiment of a method of synchronizing a clustered system may also include the step of discarding of an illegitimate packet by the first member.
[0031] An embodiment of a computer-readable storage media having computer executable instructions stored on the media, may include computer-executable instructions that when executed configure a clustered system to perform actions including relaying of information associated with a data packet from a first member of the clustered system to a second member of the clustered system before arrival of the data packet to the second member. The instructions may also when executed configure the first member of the clustered system for predicting designation of the second member to receive the data packet.
[0032] In an embodiment of a computer-readable storage media, instructions for predicting designation of the second member may also includes instructions for computing a deterministic function.
[0033] In an embodiment of a computer-readable storage media, instructions for predicting designation of the second member may also includes instructions for computing a hashing function.
[0034] In an embodiment of a computer-readable storage media, the instructions when executed may configure the clustered system for further bouncing the data packet from the second member to the first member.
[0035] In an embodiment of a computer-readable storage media, instructions for relaying information and instructions to the second member may be so configured that the information or forwarding instructions are not relayed to a third member of the clustered system.
[0036] In an embodiment of a computer-readable storage media, instructions for relaying may be configured for unicast communication.
[0037] In an embodiment of a computer-readable storage media, the instructions when executed may configure the clustered system to perform relaying of information and forwarding instructions after predicting designation of the second member.
[0038] An embodiment of computer-readable storage media having computer executable instructions stored on the media, may include computer-executable instructions that when executed further configure the first member of the clustered system to discard an illegitimate packet.
[0039] An embodiment of a clustered system may including a plurality of members, and also include a memory accessible to a first member of the plurality of members. The memory may be configured to store a state machine and an algorithm for predicting designation of a second member of the plurality of members to receive a data packet. The clustered system may further include a processor accessible to the first member. The processor may be configured to execute the algorithm.
[0040] In an embodiment of a clustered system the processor may be further configured for relaying information associated with the data packet to the second member.
[0041] In an embodiment of a clustered system the information may include instructions for the second member to bounce the data packet to the first member.
[0042] In an embodiment of a clustered system the second member may be a backup member.
[0043] In an embodiment of a clustered system the processor may be further configured to not relay the information to a third member of the plurality of members.
[0044] In an embodiment of a clustered system the processor may be further configured to relay the information to the second member by unicast communication.
[0045] In an embodiment of a clustered system the processor may be further configured to discard an illegitimate packet.
Terminology
[0046] The following terms are used in this application in accordance with their plain meanings, which are understood to be known to those of skill in the pertinent art(s). However, for the sake of further clarification in view of the subject matter of this application, the following explanations, elaborations and exemplifications are given as to how these terms may be used or applied herein. It is to be understood that the below explanations, elaborations and exemplifications are to be taken as exemplary or representative and are not to be taken as exclusive or limiting. Rather, the terms discussed below are to be construed as broadly as possible, consistent with their ordinary meanings and the below discussion.
Member—The terms “member” and “member device” and “cluster node” may be used interchangeably. A clustered system includes a plurality of member devices. Each member may serve a function which is parallel to at least one other member, such that the members are functionally interchangeable and function in parallel. Cluster—A cluster includes plurality of member devices which perform multiple instances of a task in parallel. The cluster may also be referred to as a “cluster network”, of a “clustered system”.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] Various embodiments of a method and system for predictive synchronization of a clustered system are herein described, by way of example only, with reference to the accompanying drawings, where:
[0050] FIG. 1 is a block diagram illustrating a previous art cluster having a stateless distributor;
[0051] FIG. 2 is a block diagram illustrating an embodiment of a predictively synchronized cluster having a stateless distributor;
[0052] FIG. 3 is an illustration of an example of an predictively synchronized embodiment of a cluster having a stateful distributor;
[0053] FIG. 4 is a flowchart of a method of distributing data packets over a predictively synchronized cluster;
[0054] FIG. 5 is a block illustration of a member of a predictively synchronized cluster network.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] The principles and operation of a predictive synchronization of a clustered system according to various embodiments may be better understood with reference to the drawings and the accompanying description.
[0056] Flow synchronization may be maintained among multiple cluster members in order to allow redundancy. This may be done by synchronizing each session to a backup member (the backup member is the cluster member that will handle a session in place of the “home device” in case of failure of the home device that originally handled a session). In case of dual clustered systems, the session may be synchronized to a backup member which is one of the cluster nodes in a backup cluster. Thus, in case of overall system failure of the home cluster, the backup cluster will maintain the active sessions.
[0057] Referring now to the drawings, FIG. 2 is a block diagram illustrating an embodiment of a cluster 100 using predictive synchronization. Cluster 100 contains five members: 118 a, 118 b, 118 c, 118 d and 118 e.
[0058] A client 112 on a trusted network starts a session by sending 120 a a request packet to open a connection to a server 114 on the Internet. According to a deterministic hash algorithm, a distributor 116 a designates member 118 a to receive the request packet and sends 120 b the packet to member 118 a.
[0059] Member 118 a determines that the packet's connection designators, a.k.a. 5-tuple (src IP, dst IP, protocol, src port, dst port) are not in any of the existing lookup tables and accordingly, the packet does not belong to any existing session. Therefore, member 118 a takes ownership of the new session becoming the home member for the session. Member 118 a is configured to predict the results of the deterministic hash function used by distributors 116 a and 116 b to designate a cluster member to receive a packet. Thus, member 118 a predicts that if member 118 a malfunctions, distributor 116 a will designate a backup member, member 118 b as an alternative pathway to receive further packets in the new session. Therefore, home member 118 a relays 125 a state information associated with the request packet, in a unicast manner, to member 118 b but not to other members 118 c - e. In the example, when the new session is started, state information including IP addresses and port numbers for legitimate request and reply packets are relayed 125 a from the home member 118 a to the backup member 118 b. As further packets are received, updated sequence numbers associated with the session are relayed 125 b from the home member 118 a to the backup member 118 b.
[0060] Member 118 a determines the legitimacy of the request packet, and modifies the request packet (for example to protect the identity of the trusted host using network address translation NATor to prevent message interception using VPN encryption) and sends 120 c the altered request packet (having altered IP-addresses) through a second distributor 116 b which sends 120 d the altered request packet to server 114 .
[0061] Because member 118 a is configured to predict the results of the deterministic hash function used by distributors 116 a and 116 b to designate a cluster member to receive a packet and member 118 a knows the altered IP addresses that will be used in the reply packet of the new session, member 118 a determines that distributor 116 b will designate member 118 c to receive the reply packet of the new session. Member 118 a relays 125 c instructions associated to the reply packet to member 118 c. Specifically, member 118 a relays 125 c that when a reply packet having the expected header information arrives from server 114 , member 118 c is to bounce the reply packet to member 118 a. Member 118 c will further determine (either based on a local predictive algorithm or based on instructions from member 118 a ) that upon failure of member 118 a, reply packets from the session should be sent to member 118 b (which contains a backup of the session state information, as stated above). Furthermore, member 118 a predicts that if member 118 c malfunctions, then distributor 116 b will redirect reply packets to a second backup member, member 118 e. Therefore, member 118 a relays 125 d instructions to member 118 e that if a reply packet from the session arrives at member 118 e, the reply packet should be bounced to member 118 a and that if member 118 a malfunctions, the reply packet should be bounced to member 118 b. Alternatively, member 118 c could predict the identity of backup member 118 e locally and relay instructions to member 118 e
[0062] Server 114 sends 120 e a reply packet to distributor 116 b. Based on the deterministic hash function and the altered IP addresses of the reply packet, distributor 116 b sends 120 f the reply packet to member 118 c (as predicted by member 118 a ). According to instructions from member 118 a, the reply packet is bounced 129 by member 118 c to member 118 a.
[0063] Member 118 a handled the original request packet and has all of the state information necessary to handle the reply packet. Member 118 a verifies the reply packet and sends 120 g the reply packet to distributor 116 a which sends 120 h the reply packet to client 112 . Member 118 a further relays 125 b updated state information of the reply flow (for example updated sequence numbers) to backup member 118 b. Whether and when update information is relayed to backup member 118 b depends on the flow type (e.g. TCP/UDP) and the security that is applied on the flow.
[0064] Thus, the session is synchronized only to one backup member ( 118 b ) that will actually take place of member 118 a and handle the session in case of failure of member 118 a. In case of dual clustered systems, the session will be synchronized to a backup member, which is one of the cluster members of the backup cluster. Thus, in case of overall chassis failure, the backup chassis (included the backup cluster) will maintain active sessions.
[0065] It will be understood that the above embodiment may achieve almost linear scalability in session capacity and significantly improve the performance scalability of the overall clustered system using simple distributors 116 a - b.
[0066] FIG. 3 illustrates an embodiment of a predictively synchronized cluster system employing stateful distributors 216 a and 216 b. Distributors 216 a,b store state information for each session. For example, a stateful distributer may remember on which cluster member the flow was originated. The stateful distributer may then maintain the particular flow through the particular member. Particularly, distributors 216 a, b associate request and reply packets and send all packets pertaining to a particular session to the same member of a cluster 200 . Cluster 200 contains five members: 218 a, 218 b, 218 c, 218 d and 218 e. A client 212 on a trusted network sends 220 a a request packet to open a connection to a server 214 on the Internet. According to a deterministic hash algorithm, a distributor 216 a designates a first member 218 a of cluster 200 to receive the request packet and sends 220 b the packet to member 218 a.
[0067] Member 218 a is configured to predict the results of the deterministic hash function used by distributors 216 a and 216 b. Thus, member 218 a predicts that if member 218 a malfunctions, further packets will be sent through a backup member, member 218 b. Therefore, member 218 a relays 225 a in a unicast manner state information of the request packet to member 218 b only.
[0068] Member 218 a determines the legitimacy of the request packet, modifies the request packet (using VPN encryption or NAT) and sends 220 c the altered request packet (having altered IP-addresses) through a second distributor 216 b which records the IP address of the altered request packet and sends 220 d the altered request packet to server 214 . Member 218 a also predicts that if member 218 a were to malfunction, distributor 216 b would redirect the session (based on a deterministic hash function and the IP address) by designating member 218 e as a backup member to receive further reply packets from the session. Therefore, member 218 a relays 225 c instructions to member 218 e that in case of malfunction of member 218 a, any redirected reply packets from the session should be sent to backup member 218 b.
[0069] Distributor 216 b sends 220 d the altered request packet to server 214 . Server 214 sends 220 e a reply packet to distributor 116 b. Based on stored state information, distributor 116 b sends 220 f the reply packet to member 218 a
[0070] Member 218 a handled the original request packet and has all information necessary to handle the reply packet. Member 218 a verifies the reply packet and sends 220 g the reply packet to distributor 216 a which sends 220 h the reply packet to client 212 . Member 218 a further relays 225 b updated state information of the reply flow to the backup member, member 218 b.
[0071] Thus, the session is synchronized only to one cluster member ( 218 b ) that serves as a backup member and will actually take place of member 218 a and handle the session in case of failure of member 218 a. In the case of dual clustered systems, backup member will belong to the backup clustered system. Thus, in case of overall chassis failure, the backup chassis will maintain the active sessions.
[0072] FIG. 4 is a flowchart showing a method of handling of a packet by a member of a cluster system based on the example in FIG. 2 . When member 118 a receives 361 a packet, member 118 a checks 362 a cluster forwarding table. If the packet address is in the cluster forwarding table, then the packet is bounced 329 to the owner member, as specified in the cluster forwarding table. If the packet address is not in the cluster forwarding table, then the packet is from a session that is locally owned by the member 118 a (member 118 a is the home member for the session). Member 118 a then checks 365 if the packet header information is already in the local ownership table. If the packet header information is already in the local ownership table, then the packet belongs to an existing session. Therefore member 118 a checks 366 a whether the packet is a legitimate continuation of the session. If not (for example if the packet transgresses a security requirement of the firewall and in a more specific example if the packet sequence number is not the proper continuation from a previous packet in the session) then the packet is discarded 369 a. If the packet is legitimate, then member 118 a processes 364 a the packet (for example, adding security coding, encrypting the packet, or modifying the packet header). Because the packet is from an already existing session owned by member 118 a, the local ownership table also includes the cluster address of the backup member (in this case, member 118 b ). Cluster member 118 a sends 320 the packet to its destination and relays 325 a state information of the packet to backup member 118 b.
[0073] Alternatively, the local ownership table may not include the identification of backup member 118 b. Instead, the identity of backup member 118 b may be predicted using an algorithm, as is done for a packet from a new session (as explained below) or there may be a separate lookup table of backup members.
[0074] If the packet is in neither the cluster forwarding table nor the local session table, this means that the packet is a request packet to start a new session. Therefore, member 118 a checks 366 b if the packet is a legitimate request packet for starting a new session. If the packet is not legitimate (for example, a packet that transgresses a security protocol of the firewall and in a more specifically example a packet from an Internet server that is not a response to a request sent to that server by a user on a trusted network), then it is discarded 369 b. If the packet is legitimate, then member 118 a processes 364 b the packet (for example, adding security coding, encrypting the packet, or modifying the packet header) and takes local ownership of the new session by adding session information to the local ownership table of member 118 a. In the example in FIG. 4 , taking ownership is accomplished by adding 367 the header information for both outgoing and reply flows to the local session lookup table. Member 118 a predicts 368 a that member 118 b will be used for backup flows in case member 118 a fails. In order to make this prediction, member 118 a uses the same algorithm employed by the distributors 116 a - b to designate which cluster member will receive a packet. Therefore, member 118 a adds the cluster address of backup member 118 b to the entry of the new session in the local session lookup table. Member 118 a also relays 325 b instructions to member 118 b to add the new session to the local session lookup table of member 118 b and that in the local session lookup table of member 118 b, the backup member associated with the new session will be member 118 a. Thus, if member 118 a fails and a packet from the new session is sent to member 118 b, then member 118 b will immediately accept the session, becoming the owner of the session and continuing the flow. If member 118 a returns to functionality, it will have been updated with all the session information and will be able to continue to handle the session. Alternatively, member 118 a may not instruct member 118 b to add the new session to its local session table. Then, if member 118 a were to fail, and a packet from the session were to be sent to member 118 b, then member 118 b would treat the session as a new session and update all pertinent lookup tables (in a manner similar to the description of adding 367 header information to the lookup table of member 118 a for a new session, as described above).
[0075] Using the same algorithm employed by distributors 116 a - b to designate cluster members to receive a packet and based on the modified (e.g., NAT) IP addresses computed during packet processing 364 b, member 118 a predicts 368 b that reply packets for the new session will be sent by distributor 116 b to member 118 c, and if member 118 c fails, reply packets for the new session will be sent to member 118 e. Therefore, member 118 a relays 325 c instructions to members 118 c and 118 e to add the header information of the reply flow of the new session to their cluster forwarding tables so that if member 118 c or 118 e receives a reply packets from the new session, it will bounce the reply packet to member 118 a and if member 118 a fails, then member 118 c or 118 e will bounce reply packets of the new session to backup member 118 b.
[0076] After updating all of the pertinent state tables (the local session table of members 118 a - b and the cluster forwarding tables of members 118 b and 118 e ) for the new session, member 118 a sends 320 the packet to its destination and relays 325 a updated state information to backup member 118 b.
[0077] FIG. 5 shows a block diagram of member 418 of a clustered system. In the example in FIG. 5 , member 418 is a firewall device. Member 418 includes a processor 487 for executing commands stored in memory 489 in the example illustrated in FIG. 5 , memory 489 and processor 487 are physically part of member 418 . Alternatively a memory may be external to the member, but accessible by the member. In the embodiment shown, processor 487 accesses a state machine 481 stored in memory 489 of member 418 that is used to process packets. State machine 481 includes software or data structure stored in memory 489 that stores a state of member 418 . For example, the method in FIG. 4 performs functions based on the state stored in state machine 481 . State machine 481 includes lookup tables that store state information for processing firewall transactions. In the example in FIG. 5 (illustrating an embodiment of a member 418 capable of performing the method in FIG. 4 ), memory 489 includes a local session state lookup table 483 containing a list of old sessions of which member 418 has already taken ownership and a cluster forwarding lookup table 484 .
[0078] An entry in the lookup tables may include session identification information such as a protocol identifier that indicates the type of protocol used for the transaction (e.g., TCP, UDP), a source IP address for the source of the data packet, a source port, a destination IP address, and a destination port. Each entry may also store other information, such as forwarding information and relay information indicating the internal cluster member of the packet. Corresponding information for the session may be contained in each data packet passing through the clustered system.
[0079] For each included session, local session lookup table 483 includes the IP addresses of request and reply flows for the session and the identity of the backup member of the session. For example, in an embodiment of the clustered system in FIG. 2 , performing the method of FIG. 4 , the local session lookup table of member 118 a would include the IP address of the request and reply packets of the illustrated session. The local session lookup table would also contain information associated with those IP addresses, identifying member 118 b as the backup member and members 118 c and 118 e as the reply member and reply backup member, respectively. Local session lookup table 483 may also include other information, for example the current state of a sequence number.
[0080] Cluster forwarding lookup table 484 includes an entry for each session for which another member instructed member 418 to bounce packets to the home member of that session. For example, in an embodiment of the clustered system in FIG. 2 performing the method of FIG. 4 , the forwarding table of member 118 c includes the reply IP addresses of the illustrated session and identifies member 118 a as the home member and member 118 b as the backup member of that session.
[0081] State machine 481 may include a method embodied in executable software instructions for determining how to process data packets. Member 418 may be in various states at different instances.
[0082] For example, member 418 may receive directly from a distributor a packet from a session for which member 418 is already the home member (in the embodiment of FIG. 5 , the IP address of such a packet will be in local session lookup table 483 ).
[0083] Member 418 may also receive bounced packets from another member of the clustered system, (in the embodiment of FIG. 5 , such packets will be from a locally owned session and the IP address of such a packet will be in local session lookup table 483 ).
[0084] Member 418 may also receive from a distributor packets belonging to a session owned by another cluster member. For example, in the embodiment of FIG. 2 , cluster member 118 c receives response packets of a session belonging to cluster member 118 a. In the embodiment of FIG. 5 , before cluster member 418 receives a packet from a session belonging to another cluster member, the other cluster member will have already predicted that the distributor will designate member 418 to receive the packet and will already have instructed cluster member 418 to bounce the packet to the other cluster member. Particularly, in the example of FIG. 3 , member 118 a already predicted that distributor 116 b will designate member 118 c to receive a reply packet and informed member 118 c to add the reply IP address and the identity of cluster member 118 a to the cluster forwarding table of member 118 c before the reply packet arrives. Cluster forwarding lookup table 484 has forwarding information used to bounce packets from member 418 to the home device of the session. In one example, cluster forwarding lookup table 484 includes separate entries for separate sessions. The forwarding information may include the same information as local session lookup table 483 , such as the protocol identifier, the source IP address, the source port, the destination IP address, and the destination port, to identify a session. For each entry, the forwarding information may also include the home member cluster address. This information enables member 418 to associate a session with a home cluster member. Alternatively, the local session information or the forwarding information may also be embodied in other data structures.
[0085] Cluster member 418 may also receive an unrecognized packet (defined as a packet that has an IP address not found in any lookup table of cluster member 418 ). In the embodiment of FIG. 5 , arrival of an unrecognized packet implies that member 418 should start a new session for the unrecognized packet, as explained starting in step 266 b in FIG. 4 .
[0086] Memory 489 also contains a forwarding algorithm 486 to predict which cluster member will be designated to receive a packet associated with a session. For example, in the embodiment of FIG. 2 , member 118 a includes the algorithm used by distributors 116 a - b to designate a cluster member to receive a packet associated with the new session belonging to member 118 a (packets associated with a session may include a request packet or a reply packet that is part of the session, or they may include a backup packet sent to a backup member when the home member fails), Member 418 uses forwarding algorithm 486 to predict which member of the cluster will be designated to receive a packet associated with a session. For example, in the embodiment of FIG. 2 , member 118 a uses forwarding algorithm 486 to predict that distributor 116 b will designate member 118 c to receive a reply packet of the new session belonging to member 118 a. Alternatively, if designation of members of a cluster to receive packets were to be made using more than one algorithm, then member 418 would include multiple algorithms to predict designation of cluster members.
[0087] In summary, although various example embodiments have been described in considerable detail, variations and modifications thereof and other embodiments are possible. Therefore, the spirit and scope of the appended claims is not limited to the description of the embodiments contained herein.
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A method and system is provided for a scalable clustered system. The method and system may handle asynchronous traffic as well as session backup. In the method and system, a home cluster member having ownership of a local session predicts designation of a an other cluster member to receive a packet associated with the local session and sends appropriate state information or forwarding instruction to the other network member.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to container devices, and more particularly to resealable container devices having a separate flexible internal sealing closure member which is removed before use.
2. Prior Art
Prior art container devices which utilize a foil seal on the internal walls of the container for providing a protective coating and keeping the material from which the walls are made, such as cardboard or other paper pulp material from contacting the food and possibly contaminating it due to moisture, etc., suffer from a common deficiency in that when a releasable closure member is securably adhered to the upper end portion of the device in order to close it, removal of it results in a tearing away of the foil on either the wall or the closure member which produces a ragged edge around the container device and permits pieces of foil to tear loose and contaminate the contents of the device. Many solutions have been proposed particularly in the way of various adhesives which are intended to permit an easier release of the flexible end closure member from the foil on the walls of the container, but these alternatives have proven to be unsatisfactory and have not solved the problem.
SUMMARY OF THE INVENTION
The present invention overcomes the above-described disadvantages and difficulties associated with prior art devices in that it provides a release coating over the surface of the protective coating which is normally a foil or other material covering the internal surfaces of the container, so that when the flexible foil end closure member is adhered to the release coating rather than the protective coating, the end closure member may easily be removed without tearing the foil on the closure member or removing the protective coating from the internal surfaces of the container, thus producing a beneficial result in that no aluminum pieces are permitted to drop into the container and contaminate the contents thereof, nor is a jagged or rough edge left on the container once the closure member is removed.
In addition, a resealable cover member is provided which in cooperation with an enlarged end portion of the device permits the cover member to sealingly engage the outer walls of the container so as to provide a resealable container once the internal end closure member is removed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a perspective view of a container device embodying the invention;
FIG. 2 is a partial cross-sectional view along line 2--2 of the container device of FIG. 1, illustrating the structure of the wall portion thereof; and
FIG. 3 is a partial cross-sectional view of the embodiment of FIG. 1 and additionally showing the resealable cover member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 is illustrated the cylindrical container device 10 which is usually constructed of a spirally wound cardboard material or other paper pulp type of material, often constructed in layers so that the outer surface thereof can have printed material or designs applied thereto. The preferred embodiment of the container of the present invention is illustrated as a cylindrical container device, however, it is to be understood that any shape of container device can utilize the advantages associated with the present invention, such as square or rectangular containers.
At the upper end portion 12 of the container device 10 is an outwardly offset upper portion 14 which provides a transition portion 16 in the side wall of the container device 10 which in conjunction with the cover member, to be described below, provides a resealable end portion of the container device.
On the inside wall 18 of the container device 10 is adhered a laminated film material coating 20 consisting of a plurality of layers of various thin films of material adhered together to form the film coating 20. This film coating 20 is adhered to the internal wall 18 by suitable adhesive material or by application of heat thereto, or other techniques which are well known in the art and are not considered part of this invention.
Although it is preferred that the film 20 is applied to the entire internal wall surfaces 18 of the container device, it is to be understood that it may be applied only to the upper portion of the container device 10 for reasons set out below.
The film coating 20 preferably consists of a laminate in which the central core portion 22 is made of a foil, such as a substantially aluminum alloy foil, adjacent layers 24 and 26 are preferably made of a cellophane base material and then further layers 28 and 30 of a polymer coating and then a final release layer 32, preferably on only the outer side of the film 20. The release layer 32 preferably consisting of a polymer material which will permit the layer to be pulled away from the remainder of the laminate film coating 20 without disturbing the remainder of the laminated film or pulling it away from the inner surface 18 of the container 10. A preferable material for use as the laminated member 20 is sold by the film division of Olin Corporation under the designation 103VF-58.
An alternative film which may be utilized as film 20 rather than that described above, is also marketed by the film division of Olin Corporation under the designation 112VH-58. This film differs from the above-described film in that the central core layer is made of high density polyethylene material and the adjacent layers are made of a cellophane base material with the subsequent or outer layers being made of a polymer material; with the release coating again being applied to only one surface of the laminated film so that it may be positioned on the inside of the container remote from the inner wall 18 of the container to provide a release material in the same way as mentioned above with the other laminate coating 20. The main distinction between the two materials being that the 122VH-58 is fully transparent while the 103VF-58 gives the appearance of a shiny aluminum foil; for purposes of the present invention, however, either lminated film would be satisfactory.
Referring again to FIG. 1, a flexible end closure member 34 is secured to the upper portion 14 of the device 10 before or after filling depending upon how the container is filled and sealed, for the purpose of providing an air tight and moisture tight seal on the upper portion of the container. The end closure member is preferably constructed of a flexible aluminum alloy foil. This end closure member may be applied to the upper end portion 14 of the container 10 by overlapping the foil as illustrated in FIG. 3, or it may be applied so as to abut the upper end portion of the portion 14 of the container and not overlap the side wall, in a manner which is not illustrated.
The bottom portion 36 of the container is closed with a rigid closure member such as a non-flexible aluminum alloy base plate applied to the container member in a conventional manner.
A top cover member 38 is also provided which is preferably made of an elastically deformable material which will generally retain its shape and is conventionally made of polymeric material. This cover member is so designed that it has a lower lip portion 40 which will engage the transition portion 16 of the upper end portion 14 of the container 10 when the cap is placed on the container and thus maintain the cover member 38 in sealing engagement with the upper end portion of the container member to maintain the product fresh and permit it to be reused and resealed as desired, once the closure member 34 has been initially removed.
When removing the end closure member 34 which is secured to the release coating 32 of the laminated film coating 20, the closure member is punctured and then removed, as illustrated in FIG. 1, so that a portion 42 of the release coating 32 will remain adhered to the closure member 34, when the closure member is removed. This leaves the remaining laminates of member 20 in position and prevents aluminum from either the protective aluminum coating 22 adhered to the inner walls of the container 10 or aluminum from the closure member 34, from being torn off and contaminating the contents of the container device. As was mentioned above, the film coating 20 or at least the release portion thereof, need not be applied to the complete inside walls of the container. It can be applied to only the top portion 14 where the end closure member 34 is adhered since this is the only area in which the possibility of removing aluminum foil from the inside of the container exists.
Although the foregoing descripton illustrates the preferred embodiment of the present invention, it will be apparent to those skilled in the art that variations are possible. All such variations as would be obvious to one skilled in this art are intended to be included within the scope of this invention as defined by the following claims.
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A resealable container device wherein the internal walls of the container device have a protective coating adhered thereon with a release coating on top thereof and a separate flexible protective end closure member adhered to the release coating so that removal of the end closure member leaves the protective coating intact and adhered to the inner walls of the container device; and a further cover member engageable with offset portions of the upper end of the container device so that the container may be resealed with the cover member once the protective end closure member is removed.
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FIELD OF THE INVENTION
The present invention relates generally to the manufacture of spun yarns, string, cords and other continuous thread-like materials. More particularly, the present invention relates to a modified processing system and apparatus for the production of a wide variety of yarn structures, including singles yarns, plied yarns and cabled yarns.
DESCRIPTION OF THE PRIOR ART
In conventional yarn making practice singles yarns are spun and used as basic building blocks in the manufacture of the more complex yarn structures. Prior to the spinning process, fibres, which can be of natural or synthetic origin, are prepared on a processing line which can include one or more of the steps of carding, gilling, combing, drawing and roving. The prepared material is then creeled in packages in a spinning frame where it is subjected first to a draft, or attenuation, by which the linear density is reduced to a required level, and is then twisted with an amount of twist which depends upon the weight of the yarn and its intended use. The spinning operation is thus normally carried out on a machine such as a ringframe, a cap-frame or a flyer-frame, in which the rotation of a spindle serves to both insert twist into the yarn and to wind the yarn onto a package carried on the spindle. Alternatively, the operation can be carried out on an open-end spinning machine on which twist is inserted into the yarn by rotating the forming yarn tail at a discontinuity in the supply of fibres, and in which the yarn is wound onto a package which is rotated solely for the purpose of winding.
In the manufacture of plied yarns, for example, a two-fold yarn, singles yarns are creeled onto a twisting machine such as a ring-twister, there being two singles yarns creeled for each spindle of the twisting machine. The singles yarns are delivered together at a constant speed and are twisted together and wound onto a package by the rotation of the spindle. Alternatively, two singles yarns can be wound together into a single package which is creeled on a ring-twister, or can be used on a two-for-one twisting machine. In the two-for-one twisting machine twist is inserted by continuously looping the yarn around the supply, such that two turns of twist are inserted between the two singles yarns for each revolution of the spindle. The plied yarn so formed is then wound into a package, which is rotated solely for the purpose of winding.
Conventional processing lines have several drawbacks or disadvantages which arise from the methods of processing and the way these are organized in sequence. In the spinning process it has in the past been found advantageous to include a drafting step as part of the spinning function, particularly in those processing routes where high draft ratios can be used. This, however, limits the methods that can be used to insert twist into the yarn, and the twisting action imposes an overall limitation on the productivity of the process. In open-end spinning twist can be inserted into the yarn at considerably higher rates, but open-end spun yarns have been found to suffer from significant deficiencies of structure, such that their use has become limited. Also, in spinning machines of the ring and spindle type the size of the package that can be made is limited by the gauge of the machine and the spindle speed at which it is desired to operate.
In U.S. Pat. Nos. 3,820,316 (Clarkson) and 4,034,544 (Clarkson) are described methods and apparatus for producing continuous filament or spun staple yarns in which the plied yarns are subjected to heat while tension in the yarn is relaxed, after which it is cooled and dried to enable the yarn to be twist set in a bulked condition. The objects of and the teachings of both these patents relate to the manufacture of carpet yarns which optimize the development of bulk and dyeability in plied yarns by twist setting the yarn in the presence of either dry or moist heat under relaxed tension. These patents do not describe or relate to the production of a variety of yarns by modifying a yarn processing system and apparatus to form a wide variety of yarn structures, including singles yarns, plied yarns and cabled yarns.
A further disadvantage of conventional processes lies in the need to provide separate machines of different design for the purpose of producing plied yarns. These machines can be substantially similar to spinning machines but without having means to draft the material supplied to it. The function of the plying machine is thus limited to the manufacture of plied yarns, and those machines of the ring and spindle type are further limited in the method of twist insertion and the size of the package which can be produced. The two-for-one twisting machine is less limited in package size, but by virtue of design its function is limited to that of plying.
Accordingly, it is a primary object of the present invention to provide a method and apparatus for producing a wide variety of yarn structures in a manner which avoids many of the disadvantages of the conventional processes and which provides economies of manufacture.
It is another object of the present invention to provide an apparatus which has the versatility to produce singles, plied or cabled yarns as are from time-to-time required, without the necessity of effecting extensive adjustments to the apparatus.
It is a further object of the present invention to provide a method of processing by which all the advantages of the novel apparatus can be exploited.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided a method of producing two-fold yarns in one continuous operation which includes separating a potentially highly productive drafting stage from a spinning process, and thereafter, using an apparatus which can be used to spin and ply two twistless staple yarns, inserting an amount of twist of one sense into each singles yarns whilst concurrently plying those yarns with an equal amount of twist of the opposite sense.
According to a second aspect of the present invention, there is provided a method of producing spun yarn which includes separating a potentially highly productive drafting stage from a spinning process, using an apparatus which can be used to spin singles yarns whilst concurrently inserting twist into that yarn in a two-for-one mode.
According to a third aspect of the present invention, there is provided a method of producing spun yarn which includes separating a potentially highly productive drafting stage from a spinning process, using an apparatus which can be used to produce a singles yarn whilst concurrently plying it with a two-fold yarn to produce a three-fold yarn structure. In the third aspect, the twist in the three singles components of the three-fold yarn structure can be equal in magnitude and sense whilst the plying twist between the three singles yarns can be equal in magnitude and opposite in sense to the twist in the singles yarns.
According to a fourth aspect of the present invention, there is provided a method of producing twisted yarn constructions using an apparatus which can be used to combine various existing singles or plied yarn structures to form yarns of higher complexity, such as fresco yarns and cables.
The method can be used to produce plied yarns in which the singles and plying twist senses can be twist-on-twist, twist-against-twist, or any combinations of those geometries.
The apparatus is supplied with raw material comprising packages of twistless yarns such as the slubbings produced on a woollen carding machine, or twistless yarns such as those in which fibre cohesion is achieved by means of a weak adhesive or by consolidating the fibres in a rubbing process.
The apparatus according to the present invention can also be used to perform the function of a conventional two-for-one twisting machine or to combine conventionally spun yarns into various complex structures whilst simultaneously modifying their individual twists in the initial state.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more clearly understood with reference to the examples described with reference to the accompanying drawings, which are given by way of example only, and in which:
FIG. 1 is a schematic diagram of an apparatus according to a preferred embodiment of the present invention, showing its use for the production of two-fold yarn;
FIG. 2 is a schematic diagram of part of an apparatus according to a preferred embodiment of the invention, showing its use of the production of singles yarns;
FIG. 3 is a schematic diagram of an alternative spindle design, showing also an alternative method of delivering yarn from the supply package; and
FIG. 4 is a enlarged view of an alternative type of apparatus which can be used for yarn take-off from the supply package, and means of controlling the take-off tension.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, the apparatus according to a preferred embodiment of the invention comprises a hollow spindle 1, supported by a bearing 2 in a rail 3, and has a pulley 4 by which it is driven by a drive motor (not shown). A rotor consisting of a cylinder 5 carried on top of, and which can form an integral part of, spindle 1, is penetrated by a passageway or tube 6 which interconnects with the bore 7 in the spindle 1. The passageway 6 in the cylinder 5 has an egress 8 at the top of the cylinder 5, situated closely to an ingress 9 in the cylinder wall, and which also connect with the passageway 6. On top of the spindle 1 and within the cylinder 5, a second cylinder 10 is supported on a bearing 11, such that cylinder 10 can be stationary whilst the spindle 1 and its associated cylinder 5 are rotating. Cylinder 10 has magnets 15 and a yarn guide 33 fixed close to its upper rim. Cylinder 5 can be surrounded by a third, stationary cylinder 12 which forms a guard around cylinder 5, and is securely attached to the rail 3. On top of cylinder 12 is carried a partial annulus 13, which in turn carries magnets 14, equal in number and of opposite polarity to magnets 15. Reaction between magnets 14 and 15 provides force of sufficient moment to overcome the frictional forces transmitted by the bearing 11 and windage on the surface of cylinder 10 occasioned by the rotation of cylinder 5 and spindle 1. Within the cylinder 10 is a central mandrel which comprises a fixed inner part 16 supporting an outer part 17 which is free to rotate on a low friction bearing 18. A disc 19 is attached to the lower end of the mandrel part 17, together with which it supports a package of twistless yarn 20. Mandrel part 16 has a narrowed portion at the top which supports a capstan 22 having a yarn guide at its top. Capstan 22 is a push fit on mandrel part 16 such that it can be rotated relative to part 16 by firm finger torque. A yarn guide 23 is fixed above the capstan 22 on the common axis of the spindle 1 and mandrel part 16, and a pair of rollers 24 is provided to control the rate at which yarn is delivered. A second package 25 of twistless yarn is located below the hollow spindle 1 and is supported by a mandrel 26 and capstan, of similar design to mandrel 16,17, on a rail 27. A second pair of rollers 28 can be provided so that yarn can be drafted in the zone between rollers 24 and rollers 28. A winding mechanism 29 is provided to package the plied yarn. Whilst being drafted between the rollers 24 and rollers 28, control of the fibres within the yarn is achieved by virtue of the twist within the yarn, in a similar manner to a method of achieving fibre control during drafting in the conventional woollen spinning process. By this means, draft ratios of up to 1.5 to 1 are possible, and in order to optimize the degree of fibre control in the drafting zone, a false twisting mechanism 36 can be included to temporarily modify the twist in the yarn within the drafting zone in a manner similar to that commonly used in the conventional woollen spinning process. In the present case, however, the false twisting mechanism can be used to temporarily remove or reduce the twist in the yarn rather than temporarily increase the twist in the yarn, as is the case in conventional woollen spinning.
In operation, when it is required to produce a two-fold yarn, yarn 31 from the supply package 25 is withdrawn via yarn guide 30 and the capstan on top of mandrel 26, and is then taken through the bore 7 in spindle 1 and the passageway 6 in the rotor 5 to egress at 8. Yarn 32 from the supply 20 is withdrawn via yarn guide 33 and the yarn guide in the capstan 22 to the ingress 9 in the wall of cylinder 5 where it is converged with yarn 31. Withdrawal of yarns 31 and 32 from their respective supply packages 25 and 20 sets up a low tension in the yarns between their respective supply packages and tension control capstans, this tension being just sufficient to pull the supply packages and support mandrels, causing them to rotate on the low friction bearings 18, and so deliver yarn by unwinding. Yarns 31 and 32 are then taken together via rollers 24 and 28 to the yarn winding station 29. It will be appreciated that yarn 31 is ballooned around supply package 20 by virtue of the rotation of the spindle/cylinder 1,5 rotor assembly, thereby generating one turn of real twist between the two yarns 31 and 32 for each revolution of the rotor. It will also be appreciated that, in the absence of yarn 32, the action of the rotor on yarn 31 is simply that of a false twisting mechanism, one turn of twist of one sense being generated in yarn 31 between the hollow spindle and the capstan of mandrel 26, and one turn of twist of the opposite sense being generated in yarn 31 between the egress 8 and the yarn guide 23 for each revolution of the rotor. These twists are thus mutually cancelling, and if the apparatus were to be run with only the supply package 25 of twistless yarn, then the yarn wound at the winding station 29 would also be twistless. Similarly, in the absence of yarn 31, false twist is generated in yarn 32 by virtue of the rotation of the rotor, one turn of twist of one sense being generated between the capstan 22 and yarn ingress 9, and one turn of twist of the opposite sense being generated between the egress 8 and the yarn guide 23 for each revolution of the rotor. A yarn guide 35 is provided below the spindle station for use when spinning singles yarn.
In practice, when yarns 31 and 32 are processed together, real plying twist is generated between them by virtue of yarn 31 being ballooned around the supply package 20. This plying twist is inserted at the yarn guide 23 to form a plied yarn 34 and is carried downstream with the yarn 34 from that point. In practice it has been found that by virtue of the plying torque generated at the yarn guide 23, the plying twist also tends to run against the flow of yarn some way towards the yarn egress 8. From the yarn guide 23 the plied yarn 34 is delivered via the take-off rollers 24 and the drafting rollers 28 to the yarn take-up station 29. If this plied yarn is now examined and the plying twist is removed by untwisting, it will be found that the two singles yarn components both contain twists which are equal in magnitude and sense, and are equal in magnitude but of opposite sense to the plying twist between them. This yarn structure is thus identical with a two-fold yarn of conventional manufacture in which firstly singles yarns are spun having X twists per unit length of Z twist, and two such singles yarn are plied together with X twists per unit length of S twist.
Referring now to FIG. 2, when it is desired to produce a singles yarn the lower supply package is not required and only the supply package 20 is creeled into the machine. When spinning singles yarn the flow of yarn through the passageway 6 in the wall of the rotor 5 is reversed so that yarn from supply package 20 is taken via yarn guide 33 and the yarn tensioning capstan 22 to the ingress 9 in the rotor wall, and via the passageway 6 to the bore 7 in spindle 1. From the bottom of spindle 1 the singles yarn is then taken via yarn guide 35 to the take-off rollers 24, the drafting rollers 28 and the yarn take-up station 29. By virtue of the rotation of the rotor, yarn 32 is caused to balloon around its supply package 20 between the top of capstan 22 and the axis of spindle 1. For each revolution of the balloon, one turn of twist is inserted into yarn 32 as it emerges from the capstan 22, and a second turn of twist, of the same sense as the first turn, is inserted into yarn 32 within the hollow spindle. The apparatus is then operating in a two-for-one mode of twist insertion.
An alternative design of apparatus which can be preferred for the production of some yarn types is illustrated schematically in FIG. 3 and comprises a hollow spindle 1 which is supported, for example, in a non-vertical attitude on the axis XX 1 by a bearing 2 in a rail 3, and has a pulley 4 by which it is driven by a drive motor (not shown), and a disc 5 carried on top of, and forming an integral part of, spindle 1 is penetrated by a passageway or tube 6 which interconnects with the bore 7 in the spindle 1. On top of the spindle/disc assembly a cylinder 10 is supported by a bearing 11 and such that cylinder 10 can be stationary whilst the spindle/disc assembly is rotating. Within the cylinder 10 is a central mandrel 16 which supports a package of twistless yarn 20. A flyer arm 37, integral with a capstan 22 mounted on top of, and co-axially with, the mandrel 16 is free to rotate about its axis, and assists in delivering yarn from the package 20 and in controlling the yarn tension. A yarn guide 23 is fixed above the capstan 22 on the common axis XX 1 , and a pair of rollers 24 is provided to control the rate at which yarn is delivered. A counterweight 38 is eccentrically positioned in cylinder 10 so as to deter rotation of cylinder 10 and its contents by virtue of gravitational force.
Alternatively, rotation of cylinder 10 can be deterred by magnetic means. A balloon control ring or shield 12, can be provided surrounding the ballon formation area to provide improved control of the yarn balloon during high-speed spinning. A yarn guide 35 is provided below the spindle station for use when spinning singles yarn. A second yarn supply package (not shown) is provided below the spindle, together with its associated flyer arm and support mandrel, and drafting rollers and a yarntake-up station can be provided as previously described and illustrated in FIG. 1.
In operation, and when producing singles yarn, the lower supply package is not required, and yarn 32 from package 20 is taken through the balloon zone to an inlet to the passageway 6 in the disc/spindle assembly 5,1. Yarn 32 is then withdrawn down through the hollow spindle 1 and is delivered via guide 35 to the drafting zone and the yarn winding station. By virtue of the rotation of the spindle/disc assembly 1,5, yarn 32 is caused to balloon around its supply package 20 between the guide on top of the capstan 22 and the ingress to the disc 5. For each revolution of the balloon one turn of twist is inserted into the yarn as it emerges from the capstan 22, and a second turn is inserted into the yarn 32 within the hollow spindle. In FIG. 3 the apparatus is shown producing two-fold yarn in which case the second yarn supply package is required. Yarn 32 from the supply package 20 is taken first through the balloon zone between the top of capstan 22 and the ingress to the passageway to the disc 5, through the disc and then through a second balloon stage between the egress from the disc 5 and the yarn guide 23. Yarn 31 from the second supply is taken through the hollow spindle to join with yarn 32 within the passageway 6 in the disc 5. On emerging from the disc 5 in company with yarn 32, the yarn 31 is also ballooned between the egress from disc 5 and the yarn guide 23, to form a common balloon with yarn 32. By virtue of the rotation of the spindle/disc assembly 1,5 yarn 32 is then ballooned twice around its own supply package 20; and under this circumstance for every revolution of the spindle/disc 1,5 assembly, one turn of twist of one sense is inserted into yarn 32 as it emerges from the top of capstan 22, and a second turn of twist of the opposite sense is inserted into yarn 32 as it passes through the yarn guide 23. These twists are thus mutually cancelling, and if yarn 32 were to be processed in this way in the absence of any other yarn, then the spindle would be acting as a false-twisting device and downstream of the yarn guide 23 the twist in yarn 32 would be unchanged from its initial condition. Also, by virtue of the rotation of the spindle/disc 1,5 assembly, one turn of twist of one sense is inserted into yarn 31 along the axis of rotation and within the bore 7 of spindle 1, and a second turn of twist of the opposite sense is inserted into yarn 31 at the yarn guide 23. These twists are again mutually cancelling, and if yarn 31 were to be thus processed in the absence of any other yarn, then the spindle would again be acting as a false twist device, and downstream of yarn guide 23 the twist in yarn 31 would be unchanged from its initial condition.
In practice, when yarns 32 and 31 are processed together, a real plying twist is generated between them by virtue of yarn 31 being ballooned around the supply package 20. This ply twist is inserted between the two yarns at the yarn guide 23 to form a plied yarn 28 and is carried with the yarn 28 downstream from that point. In practice, it has been found that by virtue of the plying torque generated at the yarn guide 23, the plying twist also tends to run against the flow of yarn some way into the balloon zone. From the yarn guide 23 the plied yarn 28 can be delivered via the take-off rollers 24 to a drafting zone and a yarn take-up station as previously described and illustrated in FIG. 1.
The spinning action of this alternative design of spindle is substantially the same as that previously described in relation to FIG. 1, in that when a singles yarn is produced the yarn 32 is caused to balloon continuously around its own supply package 20, two turns of twist being inserted into yarn 32 for each rotation of the spindle/disc assembly, and when a two-fold yarn is produced the yarn 31 is continuously ballooned around the yarn supply package 20 such that real twist is generated between the singles yarns 32 and 31. Again, when spinning two-fold yarns, false twist is generated in each of the singles yarns 32 and 31 between the point of delivery from their respective capstan tension controls and the yarn guide 23. Again, when producing two-fold yarn the plying twist is generated at the yarn guide 23 and is carried downstream with the yarn but also tends to run upstream towards the point at which the two singles yarns 32 and 31 are first converged, by virtue of the torque generated by the plying twist.
The spindle design illustrated in FIG. 1 offers the advantage that the yarns are not subjected to the tensions imposed by ballooning by virtue of the support provided to the balloon, or balloons, by the cylinder 5. When producing singles yarn, the yarn 32 is thus subjected only to the centrifugal force developed by the rotation of the relatively short, unsupported length of yarn between the top of the capstan 22 and the yarn ingress point 9, and by the frictional drag on yarn 32 imposed by its passage through the yarn passageways 6 and 7 plus the tension imposed at the capstan 22. When producing two-fold yarns, the yarn 31 is subjected to the forces of frictional drag by passage through the passageways 7 and 6, and the tension imposed by the capstan at its supply package, the yarn 32 is subjected only to the centrifugal force due to rotation of its unsupported length and the tension imposed by the capstan 22, and the two-fold yarn structure 28 is subjected only to the centrifugal forces due to rotation of that relatively short length of yarn between the yarn egress point 8 and the yarn guide 23 plus the tensions existing in the two singles yarns at the yarn egress point 8. The reduced forces thus imposed on a yarn during spinning when the spindle design depicted in FIG. 1 is used make it possible to process at significantly increased spindle speeds and also to manufacture yarn of significantly reduced twist.
It will be evident that, when producing two-fold yarns, it is normally preferred to subject the two singles yarns to equal tensions at the point of, and at the time of, plying. The differing paths followed by the two singles yarns 31 and 32 according to both of the spindle designs shown in FIGS. 1 and 3, can be expected to produce differing tensions in the two singles yarns 31 and 32 at the point of plying. In order to overcome this circumstance it is necessary to provide means for adjusting the overall tension in one or both of the single yarns 31 and 32 during transport from their respective supply packages and the point at which they are converged, i.e., yarn egress point 8. Tension control in the singles yarns is effected according to the present invention by means of an adjustable capstan device around which the yarn is wrapped to provide frictional drag, and incorporated as part of the supports for the two supply packages.
FIG. 4 shows an enlarged view of a flyer arm device such as that depicted in FIG. 3. The flyer arm rotates on a shaft 38 which is supported in a bearing 39 fixed in the top of the mandrel 16 carrying the yarn supply package 20. Mounted on, and co-axial with the shaft 38, is a capstan of circular section which is divided into two parts 40 and 41. Fixed to component 41 is the arm of the flyer 37, which has at one end a yarn guide 42 and at its other end a counterbalancing weight 43. The flyer arm 37 is rigidly fixed to the capstan component 41 and rotates with it. The second capstan component 40 has near its top a yarn guide consisting of a yarn ingress 44 in the wall of the capstan which connects with a yarn egress 45 in the top of the capstan and on the axis of rotation of the flyer arm. Yarn 32 from the supply package 20 is delivered via the yarn guide 42 of arm 37 to wrap the capstan component 40 before being threaded through the yarn guide comprising the ingress 44 and the egress 45 in the top of the capstan. Tension is developed in the yarn depending upon the total angle by which it wraps the capstan. The two parts 40 and 41 of the capstan are so constructed and joined together at 46 that component 40 can be rotated relative to component 41, about their common axis, and thus to vary the total angle of wrap of the yarn 32 in a continuous manner. A degree of friction is achieved between the two capstan components 40 and 41 such that their mutually relative positions will not change except by positive adjustment by a deliberate force. By this means the total overall tensions developed in the two singles yarns 31 and 32, can be separately adjusted to achieve equality of singles yarn tension at the point of plying. Further to this, it is also possible to arrange the singles yarns tensions to be unequal when it is required to produce a two-fold or other plied yarns having a fancy spiral effect.
It will be understood that yarns of more complexity than a two-fold structure can be produced if one or both of the supply packages 20 and 25 is replaced by a spun singles yarn embodying real twist, a two-fold yarn, or yarn of other structure. By this means it is possible to build up multiply yarns and cables of any desired construction. For example, if in the first instance a two-fold yarn is produced, starting with two supply packages 20 and 25 comprising singles, twistless yarns, to a linear density of R600/2 tex, and having three twists Z per inch in each ply and three twists S per inch between the two plys, and in the second instance this two-fold yarn is creeled in place of supply package 20 and is further plied with singles twistless yarn of linear density 300 tex from supply package 25, with three twist per inch S, the resulting yarn will be a three-fold construction of linear density R900/3 tex having three twists per inch Z in each of the three component singles yarns, and three twists per inch S plying twist between the three component singles yarns, and three twists per inch S plying twist between the three component singles yarns. If both of the supply packages 11 and 18 are replaced with two-fold yarn of linear density R600/2 tex having three twists per inch Z, in each ply and three twists per inch S between the two plies, and these two, two-fold yarns are then plied together with three twists per inch S then a four-fold yarn of linear density R1200/4 tex is made having three twists per inch Z, in each of the four plies, and three twists per inch S plying twist between the four plies. If, however, these two two-fold yarns are plied together with three twists per inch Z twist, for example, by reversing the direction of rotation of the spindle, then a cabled yarn structure denoted as R1200/2/2 tex is made having three twists per inch Z in each of the four component singles yarns, six twists per inch S plying twist in each of the two two-fold yarns, and three twists per inch Z cabling twist between the two two-fold yarns. Many other yarn structures can be built up in this way as will become evident from further consideration of the multiple twisting and plying actions of the spindle according to the present invention.
It will be appreciated that a raw material supply package of twistless yarn exists and is widely used in the textile industry which is suitable for use in the yarn manufacturing system according to the present invention, this being the slubbing produced by the woollen carding operation. Woollen processed slubbing is prepared on the woollen carding machine in ribbon form, which ribbon is then consolidated by rubbing between reciprocating aprons prior to being wound on the carding machine into spools comprising a multiplicity of cheeses of separate ends of slubbing. These spools are normally creeled complete at a spinning machine such as a ringframe or a mule, but the spool may also be deconsolidated into individual cheeses which are creeled separately at the spinning machine. The conventional cheese of woollen slubbing is a supply package of twistless yarn eminently suitable for use in a spinning machine according to the present invention. In conventional spinning, woollen slubbing is normally subjected to a low draft step of ratio less than 2:1, prior to the insertion of real twist into the yarn, which draft is effected against a false twist as a means of gaining fibre control. The use of a low draft is desirable as a means of improving the yarn evenness and making minor adjustments to the count of the yarn. In the process according to the present invention the drafting step can be effected after the insertion of real twist into the yarn, and to assist this drafting process that real twist may be temporarily modified by the application of a false twist in a manner similar to the conventional process.
In a further known process packages of twistless yarn can be prepared in long draft processes such as the worsted and semi-worsted systems, by means of the continental rubbing finisher, a machine designed primarily for the manufacture of twistless worsted rovings. In this machine worsted tops or slivers are first subjected to draft ratios of up to 30:1 or more in order to attenuate the slivers to a desired linear density, and are then rubbed by reciprocating aprons to consolidate the structure, and are then wound into individual cheeses of twistless roving. It has been found practical by means such as this to provide packages of twistless yarn suitable for the production according to the present invention of many yarn structures.
It will be understood that the foregoing descriptions of preferred embodiments of the present invention, and the operational features and techniques are given by way of example only, and that a number of variations and modifications are possible without departing from the scope and spirit of the appended claims.
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A method and apparatus for producing spun yarns of various constructions which includes separating a potentially highly productive drafting stage from a spinning process and thereafter by the use of an apparatus which can be used to spin and ply two yarns while inserting an amount of twist of one sense into each yarn while concurrently plying those yarns with an equal amount of twist of the opposite sense. The apparatus can also be used to spin singles yarns while concurrently inserting twist into that yarn in a two-for-one mode. The yarns can be two twistless staple yarns or a singles yarn which is spun and plied with a two-fold yarn to produce a three-fold yarn structure. The twist in the three singles components of the three-fold yarn structure can be equal in magnitude and sense while the plying twist between the three singles yarns can be equal in magnitude and opposite in sense to the twist in the singles yarns. The method can produce yarns in which the singles and plying twist senses can be twist-on-twist, twist-against-twist, or a combination of these geometries. The raw material supplied to the apparatus can be packages of twistless yarns such as the slubbings produced on a woollen carding machine, or twistless yarns such as those in which fibre cohesion is achieved by means of a weak adhesive or by consolidating the fibres in a rubbing process. The apparatus can be used to perform the function of a conventional two-for-one twisting machine or to combine conventionally spun yarns into various complex structures while simultaneously modifying their individual twists in the initial state.
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FIELD OF THE INVENTION
The present invention relates to circular knitting machines.
SUMMARY OF THE INVENTION
According to the present invention, there is provided in a circular knitting machine, a needle cylinder, means defining a control cam shell, means defining a program cam drum, said cam shell and program drum being co-axial with the needle cylinder, pawl means for advancing said drum and means for causing the drum to advance selectively through angular movements of short or long-pitch, said advancing means comprising means defining an array of seats on the drum, removable pin means located in selected ones of the seats, and control means cooperating with the pin means and operative to control the pawl means in dependence on the arrangement of the pin means so as to effect short or long-pitch advance of the drum.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a fragmentary side elevation of a circular knitting machine in accordance with the present invention;
FIGS. 2 and 3 are sections respectively taken on lines II--II and III--III of FIG. 1;
FIG. 4 shows, on an enlarged scale, a detail of FIG. 2 at a time when the control arrangement is set to provide double-frequency small-stroke angular advancements of a program drum of the machine;
FIG. 5 is a sectional view taken on line V--V of FIG. 4;
FIG. 6 shows a detail of FIG. 4 with the control arrangement set to provide single-frequency short-stroke angular advancements of the program drum;
FIG. 7 is a sectional view taken on line VII--VII of FIG. 6;
FIG. 8 is a sectional view on line VIII--VIII of FIG. 6;
FIG. 9 shows a detail of FIG. 4 at a time when the control arrangement is set to provide long-stroke angular advancements of the program drum;
FIG. 10 is a sectional view taken on line X--X of FIG. 9;
FIG. 11 shows a detail of FIG. 4 in a zero-setting control starting array;
FIGS. 12 and 13 are sectional views respctively taken on lines XII--XII and XIII--XIII of FIG. 4;
FIG. 14 is a fragmentary sectional view taken on line XIV--XIV of FIG. 11;
FIG. 15 is a schematic view of an article knitted on the machine; and
FIG. 16 is a developed view showing one possible control program.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The circular knitting machine shown in the drawings comprises a cylindrical tubular element 1 which is combined with a needle cylinder 2 and which is mounted by means of rolling bearings 3 and 5 in a fixed structure 7 (see FIGS. 1, 12 and 13). A belt pulley 9 is connected for rotation to the element 1 and is rotated by a motor and belt or the like to drive the needle cylinder 2 via the element 1. An eccentric cam 12, which is also connected for rotation to the element 1, co-operates with a roller 14A of an arm 14 which is rigidly connected to a shaft 16 (see FIG. 3). The shaft 16 is, in turn, rigidly connected to an arm 18 carrying an oscillating pawl 20 (see FIGS. 2 and 4), this arm being resiliently biased against a toothed rim 22 having inclined ratchet-like teeth of a relatively large pitch or extent P 1 . The toothed rim 22 may be produced by a mechanical working process or by the application of bars of the like.
The toothed rim 22 is adjacent a second toothed rim 24 having inclined ratchet-like teeth of a pitch P 2 which is much smaller than P 1 (see FIGS. 1 and 6). The two toothed rims 22 and 24 are mounted on the lower end of a program drum 26 carrying cams 28--36, the drum 26 being co-axial with the element 1 and extending around and beneath the lower end of the needle cylinder 2 and below a shell 37 carrying cams for the needles and jacks of the machine. Above the toothed rim 24 is a ring 38 having a series of radially-extending seats 40 (see FIGS. 9, 12, 13). In these seats 40 are located pins 42 and pins 44 of a greater length than the pins 42. An oscillating lever 46 mounted on a shaft 48, cooperates with the outer surface of the ring 38 and pins 42 and 44. The shaft 48 carries an arm 50, rigidly connected to the lever 46 and preferably coplanar with the lever 46 (see FIGS. 4 and 6). The free end of the lever 50 carries an actuator 50A associated with a micro-switch 52 of the needle cylinder speed control. Micro-switch 52 is of known design and, for example, controls a motor which drives the belt pulley 9. Micro-switch 52 drives this motor at high speed when lever 50 is fully engaged with the micro-switch 52 and, at low speed when the lever 50 is fully disengaged from the micro-switch 52 in accordance with the invention.
An arm 54 which is rigidly connected to the shaft 48 and thus also with the arms 46 and 50, acts upon a tie rod 56 (see FIGS. 3 to 10) passing through oscillating bushings of the arm 54 and an arm 58, so as to leave an operating clearance G between the tie rod 56 and arm 58. The clearance G is represented in the drawings in different positions between an edge of the arm 58 and the head 56A of the rod 56. A tooth 58A at one end of arm 58 is capable of keeping arm 14 spaced from cam 12, under the action of a spring 60 which reacts directly between arm 18 and arm 58. Movement of the tie rod 56 in the direction of arrow f 2 (see FIGS. 4, 9, 11) causes the release of the tooth 58A from the arm 14 and thereby the release of this arm. The arm 58 is mounted on a pin 62, to which an arm 64 for a manual zero-setting control, and a resiliently-biased pawl 66 are also fastened. This pawl, under normal conditions, engages a raised side 68A of a track 68, so that the tooth 58A maintains the arm 14 spaced from the cam 12. When the manual control lever 64 is moved in the direction of arrow f 4 (FIG. 11), the arm 58 is moved to such an extent as to cause, in addition to the release of the arm 14, also the release of pawl 66 from the side 68A of the track 68. This causes rapid movement of the rim 22 and also of the drum 26 until a zero-setting position is reached. The zero-setting position is defined by a radial cam projection 68B of track 68 disposed radially outwardly of the side 68A, having an inclined plane profile for effecting movement of the pawl 66 from the position in which it engages the track 68 at a position radially outwardly of side 68A, to the position in which the pawl 66, under the action of the spring 60, is released to again engage the side 68A of the track 68. This causes the arm 14 to be again retained by means of tooth 58A in the condition of maximum displacement effected by cam 12 thereby to render the pawl 20 inoperative. The rapid movement of rim 22 is achieved by the fact that arm 14, being released, permits the engagement of roller 14A on cam 12. Cam 12, being carried on tubular element 1 and rotated at relatively high speeds, oscillates the arm 14 back and forth which causes the pawl 20 to move rim 22 forwardly on each rotation of tubular element 1 by the distance P 1 . This rotation is in a direction f 8 . Once cam projection 68B comes into contact with the forward edge of pawl 66 which is on the right, as seen in FIG. 14, the inclined surface of cam projection 68B rides under this edge of pawl 66 causing it to bend upwardly slightly and also to move radially inwardly. As seen in FIG. 11, the flat surface of the forward edge of pawl 66 is shaped so as to interact with the inclined surface of projection 68B and cause it move radially inwardly of the element 1. The arm 50, which is controlled via the lever 46 by means of the pins 44 and 42 and the track formed by the outer surface of the ring 38, cooperates with an adjustable head 70 carried by an extension 72A of a rocking lever 72 pivotally connected at 74 to the fixed structure 7 (see FIGS. 4 to 10). The lever 72 is biased by a spring 76 in a direction to press a pin 78 carried at its end, onto a disc 80. The disc 80 is slidably mounted over a cam 82 provided with two hollows 82A and the disc serves to selectively vary the effective active profile of the cam 82. The disc 80 is slidably engaged for movement in the direction of the two hollows 82A by means of, for example, slots 84 on the disc, pairs of guide pins 86 on the cam 82 and engaged in the slots 84 and at least one button shaped head 88 for retaining the disc 80 in contact with the cam 82 (see FIG. 8). The disc 80 also has two holes 90 which are closely adjacent in a position in the central portion of the disc. These holes are aligned in the direction of sliding of the disc 80 (as defined by the slots 84) and either one of the two holes 90 may cooperate with pin 78 when the lever 72 is free from restraint by the lever 50, and is biased by spring 76 so that the pin 78 moves into one of the holes 90 in the surface of disc 80 when one of the two holes is located under the pin.
A roller 92 cooperates with the cam 82 and with the disc 80. The roller 92 is carried by an arm 96 pivotally mounted at 98 on the fixed structure and biased by a relatively strong spring 99 to press against the cam 82 (see FIG. 4). This action causes the disc 80 to slide back and forth in the direction of its slots so as to uncover cyclically each of the two hollows 82A each time one of them passes the roller 92 during each rotation of the cam 82, when the lever 72 is kept away from the disc 80 by the arm 50 acting on the head 70, when the lever 46 bears directly on the ring 38 in the absence of pins 42 or 44. When the lever 46 is moved by means of a pin 42 or 44, the arm 50 is moved in the direction of arrow f 6 and allows spring 76 to push on arm 72 so that this arm engages the disc 80. Under these conditions the pin 78 is positioned to move into either one of the two holes 90 as soon as one of them moves into alignment with the pin 78, which occurs within a maximum of half a revolution of the cam 82. As a result, with the lowering of arm 72 under the action of the lever 46 cooperating with a pin 42 or 44, the disc 80 is locked in one of the two positions in which it is pushed laterally by the roller 92 when the latter is in correspondence with one of the two hollows 82A. As a consequence the disc 80 extends over the other of said hollows 82A and neutralizes the action of this other hollow 82A on the roller 92.
When the disc 80 is released, at each revolution of the cam 82, the arm 96 completes two oscillations caused by the active presence of the two hollows 82A. When disc 80 is locked, at each revolution of the cam 82, the arm 96 completes only one oscillation. The two different oscillatory frequencies of arm 96 (one being double the other) are transmitted to a pawl 100 pivotally mounted at 102 on arm 96. This pawl acts on the toothed rim 24 in such a way as to cause the advancement of the cam drum 26 by the pitch P 2 at each oscillation. The cam 82 and the disc 80 are rotated by the element 1 via gears 109 and 110 and a speed reducer unit 112 interposed between the gear 110 and the cam 82. The speed reduction from the element 1 to the cam 82 may be 8:1, for example.
As long as the lever 46 engages the outer surface of the ring 38 in areas having neither pins 42 or 44, the arm 50 acts on the micro-switch 52 to maintain a high speed of the element 1 and thus of the needle cylinders, and the arm 50 acts also upon the head 70 of the lever 72 to maintain the pin 78 raised from the disc 80. Thus the disc 80 is free and is pushed cyclically in opposite directions by the roller 92. At every revolution of the cam 82 a double action, that is a double oscillation of the pawl 100 upon the toothed rim 24 is obtained. Thus an advancement of the cam shell occurs in the direction of the arrow f 8 . When the lever 46 engages a short pin 42, the lever 46 displaces the arm 50 so as to allow the lowering of the arm 72 when one of the holes 90 is moved by the pushing action of the rollers 92 into alignment with the pin 78 which is coincident with the rotational axis of the cam 82. Thereby the disc 80 is locked in the position in which it neutralizes the hollow 82A positioned after that which has caused the rollers 92 to push the disc 80. The effective active profile of the cam 82 is thereby varied. From this time, the cam 82 acts with only a single hollow 82A active on the roller 92 and therefore the pawl 100 acts only once at each revolution of the cam 82. With an 8:1 drive ratio there will be eight revolutions of the element 1 between one operation of the pawl 100 and the next under the conditions discussed above. While under the preceding conditions with the disc 80 released, one operation of the pawl 100 will occur every four revolutions of the element 1.
This change in the operating frequency of the pawl 100 on the toothed rim 24, depending upon the presence or the absence of the pins 42 on the ring 38 in a predetermined arc of the cam drum 26 enables the length of the article knitted on the machine to be changed over this arc of the cam drum. By modifying the arrangement of pins 42, the "size" of the article, relative to the length which is knitted in the above mentioned arc of the cam drum, is changed.
This working arc is defined between one or more pins 44 of greater length. During all of those phases, the micro-switch 52 is maintained under a condition in which it effects high speed drive of the needle cylinder.
When the lever 46 is engaged by a pin 44 and is further moved, the displacement of the arms 50, 54 is greater. This allows the head 50A to move away from the micro-switch 52 by such a distance as to permit the micro-switch to reduce the rotational speed of the needle cylinder. Also the longer displacement of the arm 54 causes release of the arm 14. It is to be noted that while the lever 46 was bearing on the ring 38 or a pin 42, the motion of the tie rod 56 in the direction of the arrow f 2 did not change the position of the arm 58, because the movement of the lever 46 caused by the change from absence to presence of a pin 42 simply caused the clearance G to be taken-up. Under these conditions, the arm 58 and the arm 14 remain stationary with the roller 14A being spaced from the cam 12 and therefore the pawl 20 remains inactive during continuous rotation of cam 12 at the frequency of rotation of the needle cylinder.
When the lever 46 is engaged by a pin 44, the greater stroke which this pin 44 imposes to tie rod 56 in the direction of the arrow f 2 causes the release of the arm 14 whereby its roller 14A engages the cam 12 and the pawl 20 is oscillated at a frequency dependent on the speed of the cam 12. This pawl 20 causes at each oscillation, advancement of the toothed rim 22 by a pitch P 1 and also of the program drum 26 which controls the working elements associated with the needle cylinder rotates at a lower speed as a result of the operation of the micro-switch 52. This action continues while the pins 44 are in contact with the lever 46. It is noted that, while the pawl 20 is operative to move the program drum 26, pawl 100 engaging the teeth of rim 24 is ineffective since the teeth of rim 24 having the much smaller pitch P 2 moves ineffectively beneath the pawl 100 causing it to move out of the way with each forward incremental movement of the program drum by the distance P 1 which is caused by the pawl 20. For clarity, it is also noted at this point that a single forward and functioning rotation of the program drum 26 occurs to produce a single product such as a stocking. In the absence of a pin 44 in correspondence with the lever 46, the previous conditions of advancement over the smaller pitch P 2 , either once or twice at every revolution of cam 82 are resumed. At the first movement of the arm 14 by the cam 12 following the noticed absence of a pin 44 in contact with the arm 46, the arm 58 (which is again activated by sliding of tie rod 56 in the direction opposite to that of the arrow f 2 ) hooks the arm 14 again and disengages the pawl 20.
Upon manual control of the lever 64, a displacement of the arm 58 greater than that obtained through the return of the tie rod 56, is caused, whereby the pawl 66 engages the track 68. Thereby long and rapid oscillations of the pawl 20 occur until the zero-setting position, defined by the cam projection 68B, is reached. The machine can then begin to knit a new article.
FIG. 15 shows a typical article which may be knitted on the machine, the article shown being a pair of tights. At the zone marked A in FIG. 15 the welt is started and may include elastic yarns. Zone B is a so-called turned welt. Zone C is the connection zone between B and A. Zone D is a zone of uniform knitting which is cut to make the body portion of the tights. The zone E is a connecting zone between the body portion and the leg portion where at least one yarn substitution occurs. Zone F corresponds to the leg portion and foot portion, these articles generally having no heel portion. Zone G is a yarn exchange zone, and zone H is a uniform zone comprising fabric which is to be sewn together to form a toe closure. Zones B, D, F, H or at least zones D and F may be knitted at high speed, since the fabric in these zones is uniform. In the zones A, C, E, and G, knitting is effected at a reduced speed.
Zones D and F, at least, may be modified in length to obtain required size variation.
FIG. 16 shows a development of the control program provided by the pins 42 and 44 to obtain the various parts of the article of FIG. 15. In the area denoted by A1 three long-pitch movements occur and therefore in this area there will be long pins. In the area B 1 there are short pins or no pins at all.
In area C 1 long pins are provided in order to obtain long-pitch movements so as to carry out the welt discharge program. In area D 1 short pins 42 are provided in a varying number, to obtain different lengths of the zone D of the article.
In area E 1 long pins are provided, for example, to effect two long-pitch movements. In area F 1 a varying number of pins 42 is provided to obtain the different lengths of the zone F of the article. It must be noted that a size change may be obtained also through the presence of some long pins 44, by means of which the length of the zone being knitted may be considerably shortened, since the presence of a long pin 44 causes a long-pitch movement which shortens the manufactured article by an extent corresponding, for example, to that of six small-pitch movements.
In area G 1 long pins are provided, for example to effect two long-pitch movements, and in area H 1 there are pins 42 or no pins, to obtain a generally constant length of fabric. The number of long-pitch movements in the areas A 1 , C 1 , G 1 will depend upon the required controls which will be carried out following the program to produce each of the corresponding zones A, C and G of the manufactured article.
The machine particularly described permits easy and fine changes in the dimensions of the knitted article and ensures the accurate timing of the program phases. The whole structure is carried by a single member which also comprises the speed controls. In addition a rapid zero-setting operation is provided.
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A circular knitting machine for knitting hosiery has a program drum which can be advanced through short or longer-pitch movements in dependence on an arrangement of removable pins located in seats around the drum. The presence, absence, and length of the pins is sensed mechanically by a control device associated with an incremental advance mechanism for the drum. The speed of the needle cylinder is also controlled in dependence on the arrangement of pins. By changing the arrangement, articles of different size can be produced on the machine.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
Spacecraft structures require the use of advanced lightweight and stiff composite materials in their design to meet the projected weight efficiencies of some current and most future space missions. Unfortunately, these lightweight composites, unlike bolted metallic structures, have very little inherent damping or vibration dissipation characteristics. Thus, due to their light weight and low damping, many structural subsystems with their instruments and electronic payloads, may be subjected to dangerously high vibration levels which compromise their functionality. Of particular interest here are instruments mounted on precision kinematic mounts (KM). Due to their construction techniques, these KM's have very little inherent damping, thus accentuating instrument vibration environment during flight. These environmental effects are brought about during powered flight and pyrotechnic separation/release events. In fact, 14% of spacecraft launches through 1984 (600 launches) suffered vibration/shock related failures. Of these failures, 50% resulted in catastrophic mission loss.
Currently, there are on-going efforts to define graphite structure modifications which lower the overall level of vibration response throughout spacecraft structures. Test and analysis results from a number of space projects using constructions of lightweight graphite composites indicate that the level of reduction likely to be achieved may not be sufficient to bring already developed instruments within their design levels. The need thus arises to identify and make ready for development additional vibration reduction techniques for instruments should the spacecraft structure reduction be proven to be insufficient. In FIG. 1, the instrument 10 is represented by a rectangular solid depicted by broken lines. The instrument 10 is supported by six small precision ground flat pads 12, 14, 16, 18, 20, 22 which only resist loads perpendicular to their plane (individually, they cannot resist bending moments). Under gravity, the three pads 12, 14, 16 support the weight of the instrument 10, i.e., they provide restraint in the z direction. In addition, they restrain the instrument 10 against rotations along the x and y axes. Pads 18, 20 restrain the instrument 10 against translation along the y axis and rotation along the z axis. Finally, pad 22 restrains it against translation along the x axis.
In practice however, it is very difficult to design a linear system of supports which will only provide restraints against translations and none in rotation (i.e. bending action). Conventional designs of three kinematic mounts are depicted in FIGS. 2A-2C. The three mounts are denoted by 24, 30 and 36 in FIGS. 2A-2C, respectively. They comprise a collection of bars 30, 32, 34, 38, 40, 42, 44 attached together. The mount 24 (FIG. 2A) is designed to restrain the instrument predominantly in the axial direction along the longitudinal axis of bar 30, as shown by the arrow 25. At the top and bottom of bar 30, notches 26, 28 have been machined to simulate hinge action, and thus minimize restrains against lateral translations and rotations along three axes. In like manner, mounts 30 (FIG. 2B) and 36 (FIG. 2C) are designed to provide translation restraints predominantly in two and three directions as shown by arrows 31 and 37, respectively. Instruments have been mounted to spacecraft via conventional arrangements of mounts 24, 30 and 36. For a given instrument, particular performance requirements are formulated that specify the maximum values of stiffness the extra restraints can have, which are in excess of the six required for an ideal kinematic mount.
Kinematic mounts, such as those shown in FIG. 2 have met with limited success. Even though these mounts are designed to safely carry the launch loads, the designs have no provisions to minimize loads transmitted to the instrument 10. In particular, the six suspension modes introduced by the mounts are expected to have very little damping, thus amplifying flight loads to the mounted instrument 10.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide kinematic mounts which incorporate novel damping features. It is another object of the present invention to provide a kinematic mount having a passive energy dissipating mechanism to protect the instrument from potentially damaging flight loads.
It is a corollary object of the present invention to provide a kinematic mount that may be incorporated on existing KM structures.
It is a further object of the present invention to provide a kinematic mounting scheme which uses six identical strut elements in order to greatly reduce manufacturing complexity and costs.
It is another object to the present invention to slightly rearrange the six strut configuration in order to approximately uncouple the mount suspension modes, thus further improving KM performance.
It is yet another object of the present invention to provide kinematic mounts that achieve modal vibration tests on coupon sample mounts that yield modal damping values from 5-17% of critical damping, which are at least one to two orders of magnitude greater damping than existing designs.
These and other objects are achieved by a damped instrument kinematic mount comprising instrument support means with first and second damping means wherein the damping means and instrument support means are arranged to provide the desired performance characteristics. The device, due to its generic nature can be applied to a large number of precision or optical instruments/sensors where alignment stability is important.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 depicts a conventional example of a kinematic mount arrangement.
FIGS. 2A-2C depict exemplary designs of conventional kinematic mounts.
FIGS. 3A-3B depict cross-sections of damper designs according to two preferred embodiments of the present invention.
FIG. 4 depicts an exemplary arrangement pattern for kinematic mounts.
FIG. 5A illustrates a side view of a single strut according to a preferred embodiment of the present invention.
FIG. 5B illustrates a cross-section of a single strut taken along line A--A in FIG. 5A.
DETAILED DESCRIPTION OF THE INVENTION
Kinematic mounts are used extensively as base supports for precision optical instruments and other high performance machinery. For space based applications, these mounts must fulfill two major requirements: 1) it must not adversely affect the stability of the instrument through the attachment to a less precise spacecraft structure and, 2) it must provide a strong and stable support system to the instrument during launch, and minimize the loads transmitted to the mounted instrument.
The first requirement can be accomplished if the mounting system constrains only the six rigid-body modes of the instrument, without restraining the instrument in any other degree-of-freedom of motion. This is equivalent to a statically determinate mounting system, which in effect will isolate the instrument from unpredictable moment loads due to a non-ideal spacecraft interface and differences in thermal expansion rates.
According to the preferred embodiments of the present inventions, the kinematic mounts have been modified by inserting vibration damping materials into the mounts. These damping materials introduce a damping mechanism into the six mount suspension modes, thus dissipating into heat and reducing the high energy disturbances to the instrument. The modifications to the kinematic mounts preserve the fundamental features, such as strength, stiffness and kinematic features.
The damping mechanism may be provided at machined hinge or flexure locations of the mounts 26, 28, 32, 34, 38, 40, 42, 44. For the above mentioned six mount suspension modes, the most active portion of the mounts will occur at these flexural hinge locations. These relatively active areas can be taken advantage of by designing local dampers at these locations. This can be done in a number of ways, with two embodiments of the damper design depicted in FIGS. 3A and 3B.
A first embodiment of the damper design is identified in FIG. 3A. This embodiment uses a spherical damper 46 placed around a flexure area 62. The flexure area 62 results from notching 26, 28 of the bar stock 30 used as instrument support means 24. The spherical damper 46 is composed of two partial shells 48, 50 which are concentrically arranged. The first shell 48 is placed partially over the second shell 50. The second shell 50 may be of a solid design. These two partial shells 48, 50 are connected together via a relatively soft layer of viscoelastic (VEM) damping material 52 bonded on one side to the outer surface of shell 50 and bonded on the other side to the inner surface of shell 48. Both partial shells have cylindrical extensions 54, 56 attached rigidly to the bar portion of the mount at locations 58 and 60. As the mount 46 deforms under launch loads, the mount 46 will experience elastic rotations at flexural hinge locations 62 at both ends of the bar 26, 28. Any bending action with center of rotation 62, will activate the spherical damper 46 by forcing the damping viscoelastic layer 52 to deform in shear, thus dissipating vibration energy in the form of heat. By selecting appropriate VEM 52 with the proper shear modulus, material loss factor and thickness, significant levels of damping can be designed into the suspension vibration modes of the kinematic mount 46. In one embodiment, the two partial shells 48, 50 are composed of titanium alloy. In an alternate embodiment, the two partial shells are non-metallic.
At first glance, it might appear that the addition of the damper adds unwanted bending stiffness to the mount 46, and compromises proper kinematic mount action. However, this turns out not to be the case. This is because the VEM properties are frequency (and temperature) dependent in a known manner. At relatively high frequencies, where the suspension modal frequencies occur, the VEM shear modulus is relatively high causing the mount 46 to have higher bending stiffness and thus also dissipate launch loads. However, when on-orbit, where the kinematic mount action is sought for, thermal loads occur at very low loading rates or frequencies. At these low frequencies, which are typically a small fraction of a Hertz, the modulus of the VEM 52 is drastically reduced by at least a factor of 20-30 or more compared to the high frequency range. Thus, the added damper stiffness in the thermal load regime is negligible, when compared to the bending stiffness contributions from the metallic flexural hinges 62. Because of these unique frequency dependent properties of particular space qualified VEM 52, they are viable candidates in damping kinematic mounts during flight.
An alternate embodiment for the damper design is depicted in FIG. 3B. This embodiment uses a cylindrical slot damper 66. The damper 66 uses a series of o-rings 68 placed within a plurality of slots 65. The o-rings 68 are space qualified high damping VEM. The slots 65 are disposed about the resulting flexural hinges 64. Instead of using a single flexural hinge 62, a number of shorter flexures are machined into the mount bar stock 64. The o-rings 68 are subjected to tensile or compressive forces, depending on the vibrational force applied to the instrument 10. Because of their light weight and strength, titanium alloy metals are commonly used to manufacture mounts 66. Whereas the spherical damper discussed above functioned by inducing shearing deformation in the VEM, this design induces compression/tension into the VEM. As far as damping performance is concerned, the damping or loss factor of the material in compression/tension is the same as in shear. It becomes apparent when studying FIG. 3B in more detail, that VEM washers could be used instead of VEM O-rings 68. In each case, we will have slightly different bending stiffness characteristics which can be tailored.
A series of flat washers 68 was modeled and analyzed. The model includes a solid finite element model of a series of four aluminum (aluminum was selected for this exercise since coupons samples will be made using aluminum) flexures each 0.15 inch long and 0.3125 inch diameter, and four VEM washers 0.020 inch thick and 1.3125 inch diameter. The analysis results indicate that for a VEM washer 68, made of ISD 112 material manufactured by the 3M Company, the six suspension modes can be damped by as much as 10% of critical modal damping. A 10% damping is at least an order of magnitude increase in damping over the untreated mount. Thus, the flight induced random vibration response of the instrument 10 due to these suspension modes will roughly drop to a level of the square root of (1/10), or 0.32 of the response with the untreated mounts. This is considered a significant performance improvement over the design without the damping treatment, since the instrument is now exposed to only about one third the loads at the high energy mount modes.
In the section above it was mentioned that an infinite arrangement of six restraints exist to obtain kinematic mount (KM) action. Optionally, alternative damped KM design concepts may be used according to the present invention so long as they satisfy the objectives mentioned above. Due to their very efficient stiffness to weight ratios, truss structures may be used. Alternatively, a set of three damped versions of the mount 30 configuration depicted in FIG. 2B may be used to provide a KM system. These can be arranged at the base of the instrument 10 in a variety of configurations. A classical arrangement pattern is shown in FIG. 4. In this figure, each of the six mount truss elements 74 is depicted as line elements for clarity. The damped flexure hinge designs 46, 66 discussed in the previous section (FIGS. 3A & 3B), are applicable to the present case equally well. Drawing from the design in FIG. 3B, each of the six struts 74 depicted in FIG. 4 may take the form shown in FIG. 5A. The embodiment of FIGS. 5A and 5B may use only a single strut design, since all six bars 74 may be identical to one another. This is a significant design simplification since often each of the mount elements 30 and 36 may be machined monolithically from blocks of metal. In contrast, the design depicted in FIGS. 5A and 5B involves only simple machining of standard bar stock. In a preferred embodiment, the standard bar stock may be a titanium alloy.
In addition to the simple design of the mount concept described above, there are other benefits and desirable features of the proposed mounting concept. Rather than using the classical "v" configuration as shown in FIG. 4, each pair of struts 30 can be arranged in such a manner that their axial lines-of-action intersect at selected points within the instrument 10. If these three line-of-action intersection points are selected to be in the same horizontal plane as the instrument center-of-mass, then the six suspension vibration modes of the instrument 10 become approximately uncoupled. This mounting scheme constitutes a center-of-gravity mounting system, in addition to being a KM. To obtain a set of six nearly uncoupled modes is often important in applications where dynamic disturbances are inherent within the instrument. For instance, if the instrument has rotating parts which induce lateral imbalance forces near mount frequencies and passing through its center-of-mass, then the instrument with uncoupled modes will only move laterally, without rotationally disturbing the instruments' line-of-sight. Clearly, not all instruments may require this type of performance, however, if they do, the proposed mounting scheme provides this capability.
From the foregoing description it will therefore be appreciated that the present invention enables the use of damped kinematic mounts to protect instruments from potentially damaging flight loads. While the invention has been described with reference to various illustrative embodiments, it will generally be understood by those skilled in the art that various changes may be made and equivalents be substituted for elements thereof without departing from the true spirit and scope of the invention.
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A damped instrument kinematic mount providing novel damping features to protect instruments from damaging flight loads. The mounting scheme utilizes any number of identical strut elements to greatly reduce manufacturing complexity and costs. Improved kinematic mount performance is achieved by arranging the six strut configuration to approximately uncouple the mount suspension modes. A spherical joint damper is located at strut flexure locations and utilizes a viscoelastic damping material that deforms in shear. Alternatively, cylindrical slot mount dampers are placed at strut flexure locations. The cylindrical slot mount dampers use o-rings or washers placed within the slotted machined mount bar stock. The kinematic mounts can then be arranged in a classical truss arrangement pattern or other configuration providing desired damping characteristics.
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BACKGROUND OF THE INVENTION
‘Minervares’ is a product of a breeding and selection program for outdoor pot mums (garden mums) which had the objective of creating new chrysanthemum cultivars with a decorative type flower, a natural season flower date around September 1-6; blooming for a period of 5 weeks. The new plant of the present invention comprises a new and distinct cultivar of Chrysanthemum plant ‘Minervares’ is a seedling resulting from the open pollination among groups of chrysanthemum cultivars maintained under the control of the inventor for breeding purposes. The new and distinct cultivar was discovered and selected as one flowering plant by Rob Noodelijk on a cultivated field in Rijsenhout, Holland in September 1998. The plant has been asexually reproduced by cuttings in greenhouses at Rijsenhout, Holland. The new cultivar has been found to retain its distinctive characteristics through successive propagations.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention of a new and distinct variety of chrysanthemum is shown in the accompanying drawings, the color being as nearly true as possible with color photographs of this type.
FIG. 1 shows a plant of the cultivar in full bloom.
FIG. 2 shows the various stages of bloom of the new cultivar.
FIG. 3 shows the various stages of foliage and petiole of the new cultivar.
DESCRIPTION OF THE INVENTION
This new variety of chrysanthemum is of the botanical classification Chrysanthemum morifolium . The observations and measurements were gathered from plants grown out door in Rijsenhout, Holland under natural day length and temperature and planted week 22 in 1999 and 2000. The natural blooming date of this crop was September 1-6 (week 36). The average height of the plants was 35-40 cms. No growth retardants were used. No tests were done on disease or insects resistance or susceptibility. No tests were done on cold or drought resistance. This new variety produces medium sized blooms with white ray florets and a yellow disc-florets blooming for a period of 5 weeks.
From the cultivars known to inventor the most similar existing cultivar in comparison to ‘Minervares’ is ‘TOLIMA’ (U.S. Plant Pat. No. 6,988). When ‘TOLIMA’ and ‘Minervares’ are being compared the following differences are noticed: The differences of ‘TOLIMA’ and ‘Minervares’ are (1) Flower form. The flowers of ‘TOLIMA’ are more decorative (2) Flower color. The flowers of ‘TOLIMA’ are more pure white (less cream white) (3) Natural blooming date. ‘Minervares’ flowers earlier.
The following is a description of the plant and characteristics that distinguish ‘Minervares’ as a new and distinct variety.
The color designations are taken from the plant itself. Accordingly, any discrepancies between the color designations and the colors depicted in the photographs are due to photographic tolerances. The color chart used in this description is: The Royal Horticultural Society Colour Chart, edition 1995.
Table 1: Botanical Description of CULTIVAR ‘Minervares’
Bud:
Size.— Small; cross-section 1.0 cm, height 0.7 cm.
Outside color.— Green-yellow 1 D.
Involucral bracts.— 2 rows, length 7 mm, width 3 mm.
Involucral bracts among disc - florets.— Not present.
Involucral bracts color.— Green 138 B.
Bloom:
Type.— Duplex daisy.
Height.— Flat, 1.2-1.5 cm.
Size.— Medium.
Fully expanded.— 4.5-5.0 cm.
Number of blooms per branch.— Approx. 4-5 blooms per branch.
Performance on the plant.— 5 weeks.
Seeds ( if crossed ).—Produced in large quantities, ovate. Grey-brown 199 A, 2 mm in length.
Fragrance.— Typical chrysanthemum.
Color:
Center of the flower ( disc - florets ).—Immature green-yellow 1 D. Mature yellow 12 A.
Color of upper surface of the ray - florets.— Yellow 4 D.
Color of the lower surface of the ray - florets.— White 155 B.
Tonality from distance.— A garden mum with white flowers and a yellow disc.
Color of the upper surface of the flowers after aging of the plant.— White 155 B.
Ray florets:
Texture.— Upper and under side smooth.
Number.— 80-100.
Cross - section.— Flat.
Longitudinal axis of majority.— Straight, sometimes reflexing.
Length of corolla tube.— Short, 0.5-0.7 cm.
Ray - floret margin.— Entire.
Ray - floret length.— 2.2-2.5 cm.
Ray - floret width.— 0.4-0.7 cm.
Ratio length/width.— Medium.
Shape of tip.— Dentate.
Disc florets:
Disc diameter.— 0.7 cm.
Distribution of disc florets.— Numerous, visible at a mature state of flowering.
Shape.— Tubular.
Color.— Yellow 12 A.
Receptacle shape.— Conical raised.
Reproductive organs:
Stamen ( present in disc florets only ).—Thin, 3 mm in length.
Stamen color.— Yellow-green 144A.
Pollen.— Present.
Pollen color.— Yellow 12 A.
Styles.— Thin.
Style color.— Yellow-green 144 A.
Style length.— 4 mm.
Stigmas color.— Yellow-green 144 A.
Stigma width.— 1 mm.
Ovaries.— Enclosed in calyx.
Plant:
Shape.— Semi upright.
Growth habit.— Spreading.
Growth rate.— Rapid.
Height.— 35-40 cm.
Width.— 30-35 cm.
Stem color.— Green 138 B.
Stem strength.— Strong.
Stem brittleness.— Present.
Stem anthocyanin coloration.— Absent.
Length of lateral branch.— From top to bottom 15-17 cm.
Lateral branch color.— Green 138 B.
Lateral branch, attachment.— Strong.
Branching ( average number of lateral branches ).—Prolific with 6-7 breaks after pinching.
Peduncle length.— 4.0-4.5 cm.
Peduncle color.— Green 138 B.
Natural season blooming date.— September 1-6.
Foliage:
Color of mature leaves.— Upper side yellow-green 147 B. Under side yellow-green 147 C.
Color of immature leaves.— Upper side yellow-green 146 A. Under side yellow-green 146 B.
Size.— Small; length 4.5 cm, width 4.0 cm.
Quantity ( number per lateral branch ).—13-15.
Shape.— Round.
Texture upper side.— Glabrous.
Texture under side.— Pubescent.
Venation arrangement.— Palmate.
Shape of the margin.— Serrated.
Shape of base of sinus between lateral lobes.— Acute.
Margin of sinus between lateral lobes.— Converging.
Shape of base.— Truncate.
Apex.— Mucronate.
TABLE 2
Differences with the comparison varieties
(when grown under the same conditions)
‘Minervares’
‘TOLIMA’
Flower form
Duplex daisy
Decorative
Flower color
Creamy white,
More pure white, center
with a yellow
is slightly cream white
white center
Natural
September 1-6
September 22-26
blooming
date
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A chrysanthemum plant named ‘Minervares’ characterized by its medium sized blooms with white ray florets and prolific branching; natural season flower date September 1-6; blooming for a period of 5 weeks.
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FIELD OF THE INVENTION
This invention relates to balloon dilation catheters and, more specifically, to dual lumen adjustable stiffness exchange catheters.
Background of the Invention
Catheters comprise tube-like members inserted into body cavities for diagnostic or therapeutic medical reasons. One of the therapeutic procedures applicable to the present invention is known as percutaneous transluminal coronary angioplasty (PTCA). The first PTCA procedure was developed in approximately 1976 by Dr. Andreas Gruntzig. His fixed wire system features a core or guidewire fixed within a catheter having an inflatable balloon at the distal catheter end with the guidewire stiffening the catheter so that it could be pushed into a desired position in the vascular system. The balloon could be positioned across a blockage and inflated to cause the blockage to be decreased.
If a catheter must be exchanged for a different catheter or one of a different size, a system in which the catheter is inserted over a guidewire is advantageous because the guidewire can be left in place during catheter exchange. The catheter is withdrawn along the guidewire and another catheter is slid into place over the guide wire. Removing the catheter requires removal of the guidewire with possible problems in the guidewire recrossing the stenosis.
Alternatively, a very long "exchange" guidewire, typically about 300 cm long, may be used. Such a long guidewire is difficult and time consuming to handle, requiring two operators and the attendant risk of contamination of the guidewire through contact with objects outside the sterile field. A two-part guidewire may be used instead of the very long guidewire. This arrangement is, however, undesirable because of the additional time required for assembly and the increased thickness that may make smooth exchanges difficult.
Rapid exchange catheters have been developed to eliminate the disadvantages of the long "exchange" wire in over-the-wire systems. These catheters have short guidewire lumens passing through the balloon so that the guidewire exits from the catheter closer to the balloon than to the proximal end of the catheter. This permits the physician to hold the guidewire as he or she removes the catheter with the exchange occurring over the shorter guidewire lumen.
Typical of such rapid exchange catheters are those described by Samson et al. in U.S. Pat. No. 4,597,755, by Horzewski et al. in U.S. Pat. No. 4,748,982 and Bonzel in U.S. Pat. Nos. 4,762,129 and 5,232,445. Short guidewire lumens through or along side the balloon are described by Kontos et al. in U.S. Pat. No. 5,180,367. Arrangements for varying the stiffness of catheters in over-the-wire catheters to aid in controlled insertion have been described by Hess in U.S. Pat. No. 4,927,413 and Scopton et al. in WO Patent No. 92/17236. An adjustable stiffness dilation catheter is described by Fugoso et al in U.S. Pat. No. 5,545,138.
While many of these arrangements provide acceptable results when used by a skilled practitioner, problems remain. Many of the multi-lumen catheters, especially those with two lumens, one for movement along a guide wire and the other for balloon inflation liquid and for a variable stiffening wire have an oval or elliptical cross section with a maximum diameter greater than is desirable. Further, the degree of stiffness along different portions of the catheter is not optimum and cannot be varied to the degree desired. Where the distance over which a stiffening wire can be inserted into a catheter is variable, maintaining a particular desired insertion distance is often difficult. Thus, there is a continuing need for improved dilation catheters in which stiffness along the length of the catheter can be varied in a desired and accurately reproducible manner.
SUMMARY OF THE INVENTION
The above-noted problems, and others, are overcome in accordance with this invention by an elongated dilation catheter having a dual lumen distal end including a relatively short first shaft for carrying a balloon and for having a first lumen for receiving and moving along a guide wire and a second, elongated, shaft having a second lumen in fluid connection with the balloon and for simultaneously receiving a stiffening wire for movement between predetermined positions within said second lumen. The proximal end of said second lumen is operatively connected to a manifold for introducing fluid into said second lumen and for moving the stiffening wire along said second lumen.
The first and second shafts and corresponding lumens are secured together in parallel. The catheter has a generally circular cross section in this region, provided by a novel forming process.
For optimum effectiveness, the stiffening wire tapers in a stepped manner from a maximum diameter at the proximal end, stepping down to a narrower diameter at a selected catheter mid-point and stepping to a still narrower diameter near the balloon proximal end.
A handle means is secured to the proximal end of the stiffening wire at the catheter proximal end for varying the insertion of the stiffening wire into said second lumen over a predetermined movement distance. A positive stop is provided to assure consistent, reproducible, maximum insertion of the stiffening wire into said second lumen. Further, a positive stop is also preferably provided at the catheter distal end to consistently limit the maximum insertion of the stiffening wire relative to the balloon. The positive stop prevents damage to the balloon interior and provides for transmission of force thereto.
It is an object of this invention to provide a stiffening wire having improved adjustability and optimum stiffness variation along the catheter length for enhanced pushability and trackability. Another object is to provide positive, reproducible, stops to assure the optimum maximum stiffening wire insertion and tip location relative to the balloon. A further object is to provide a dual lumen catheter having a substantially round external cross section.
BRIEF DESCRIPTION OF THE DRAWINGS
Details of the invention, and of preferred embodiments thereof, will be further understood upon reference to the drawing, wherein:
FIG. 1 is a plan view of the catheter assembly of this invention;
FIG. 2 is a plan view of the stepped stiffening wire;
FIG. 3 is a section view through the manifold assembly shaft region;
FIG. 3a is a detail axial section view through an alternative embodiment of the handle portion of the manifold assembly;
FIG. 4 is a generally axial section view through the proximal to mid-joint shaft section;
FIG. 5 is a generally axial section view through the balloon assembly and rail section;
FIG. 6 is a transverse section view taken on line 6--6 in FIG. 5;
FIG. 7 is a transverse section view taken on line 7--7 in FIG. 5 with the balloon in the wrapped configuration;
FIG. 8 is the manufacturing assembly; and
FIG. 9 is the method of manufacturing block diagram.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, there is seen a dilation catheter 10 having adjustable stiffness and the other features of this invention. Basically, catheter 10 includes a manifold 12 (detailed in FIG. 3) having a first branch 14 for the introduction of pressurized liquid into a longitudinal balloon inflation lumen running the length of balloon inflation shaft 16. Manifold 12 includes a second branch 18 through which a stiffening wire 22, as seen in FIG. 2, is inserted into the balloon inflation lumen. A handle 20 on branch 12 is secured to the proximal end of the stiffening wire 22 and adjusts the distance the wire is inserted into a catheter lumen, as detailed below. Balloon inflation shaft 16 preferably is formed from two or more materials in two or more sections. In the embodiment shown, a proximal section 24 is made from a relatively stiff material for optimum pushability connected at joint 26 (as detailed in FIG. 4) to a relatively more flexible material for optimum trackability. The mid-shaft section is connected to a more stiff distal section as detailed in FIG. 5 for improved lesion crossing. As seen in FIG. 1, section 24 is connected at joint 29 to a stiffer distal section 28 for lesion crossing.
A guidewire shaft 30, (as detailed in FIG. 5) is provided at the distal end of distal section 28, secured to balloon inflation shaft 16 adjacent to and extending through balloon 32 (as shown in cross section in FIG. 5). Guidewire shaft 30 is substantially parallel to balloon inflation shaft 16 and is surrounded by a filler material and tube assembly as detailed in FIG. 6.
A typical stiffening wire 22 for insertion into the balloon inflation lumen of a balloon catheter is shown in FIG. 2. Wire 22 has a length such that when fully inserted into the balloon inflation lumen within balloon inflation shaft 16 the distal wire end will lie at a predetermined location adjacent to balloon 32. The proximal end 36 of stiffening wire 22 includes means for connection to handle 20. An enlarged ball-like end may be provided for snapping into a corresponding aperture in handle 20. Alternately, a hook like end or other shape, mechanically or adhesively secured to handle 20 may be used if desired.
Stiffening wire 22 is reduced in diameter in steps from the proximal to the distal end to provide maximum stiffness and pushability at the proximal end and lower stiffness and greater trackability near the distal end. Wire 22 also is dimensioned to provide adequate inflation and deflation times. While stiffening wire 22 can be formed from any suitable material, stainless steel or nitinol are preferred for an optimum combination of stiffness and formability. For optimum performance, the distal end of stiffening wire 22 has a diameter of from about 0.004 to 0.008 in. and extends to a location about 1 to 10 mm into the balloon 32. The proximal section of wire 22 is stepped to a diameter of from about 0.006 to 0.011 inch from about 0.004 to 0.008 inch at first step 38. The mid-section extends to second step 40. At second step 40, wire 22 is preferably stepped down to a diameter of from about 0.004 to 0.008 inch. The distal end of stiffening wire 22 preferably extends to a position inside balloon 32 when fully inserted.
Details of manifold 12 are shown in an axial section view in FIG. 3. Manifold body 42 includes a first branch 14 through which pressurized fluid medium can be introduced into the balloon inflation lumen within balloon inflation shaft 16. A second branch 18 permits straight-line entry of stiffening wire 22 into the balloon inflation lumen. A flexible nose piece 44 (for strain relief) is secured to the distal end of manifold body 18 and surrounds the proximal end of balloon inflation shaft 16. A sealant 46, typically an adhesive such as cyanoacrylate or epoxy resin that is curable by visible or ultraviolet light, secures the distal end of balloon inflation shaft 16 to manifold body 18.
A cap 48 is threaded into the open proximal end of second manifold branch 18. An elastic seal 50, typically a silicone or urethane resin ring, is interposed between cap 48 and body 18. Stiffening wire 22 enters through an axial opening in seal 50 and passes into the balloon inflation lumen in balloon inflation shaft 16. The proximal end of stiffening wire 22 is secured to a handle 52 that abuts cap 48. Cap 48 can be tightened to compress seal 50 to prevent pressurized fluid leakage (positive or negative) along wire 22 through the cap while still allowing movement of the stiffener.
A stop ring 54 is preferably formed around stiffening wire 22 at a predetermined distance from seal 50. A hypotube support cover may be used in which stiffening wire 22 is placed to provide support when the handle is separated from the manifold at cap 48. The distance the stiffening wire is inserted into the balloon inflation lumen can be varied by moving handle 52 relative to cap 48. Maximum insertion occurs when handle 52 is in abutting contact with the end of cap 48. Minimum insertion occurs when handle 52 is moved away from cap 48 to the point where stop ring 54 engages seal 50.
Handle 52 includes a tubular flange 56 that is a tight friction fit over cap 48. This will prevent accidental movement of handle 52 away from cap 48 during use of the catheter.
If desired, a keying arrangement between cap 48 and handle 52, such as a pin-like projection 53 (As seen in FIG. 3a) on the inner surface of handle projecting into a corresponding recess in cap 48, a pattern of interlocking ridges and grooves between handle 52 and cap 48, etc., so that rotation of handle 52 with the interlock engaged through contact between cap and handle will rotate cap 48 between a tight and loose seal configuration.
In general, it is desirable for the proximal portion of balloon inflation shaft 16 to have greater stiffness for optimum pushability when inserting the catheter into a body vessel and for the distal portion to have greater flexibility for improved tracking along curved vessels. To aid in this stiffness variation, a transition region is provided as shown in axial section view in FIG. 4. Proximal section 24 of the balloon inflation shaft 16 is preferably formed from a relatively stiff material, such as a polyimide. Distal section 28 is preferably formed from a more flexible, low distortion, material, such as polyethylene. Any other suitable materials having these desired characteristics may be used. The two materials are joined together at an overlapping, adhesively bonded joint 26.
In order to further and variably adjust the stiffness of the catheter, the stepped stiffening wire 22 is positioned in the inflation lumen 16. The first stepped decrease in thickness preferably is positioned in the general area of joint 26. As described above, by moving handle 52 the specific position of step 38 can be varied relative to joint 26.
Details of balloon 32, guidewire shaft 30 and related components are shown in the axial section view of FIG. 5 and the transverse section views of FIGS. 6 and 7.
Balloon 32 is shown in the inflated condition in FIG. 5 and in the folded condition in FIG. 7. A pressure resistant material, such as polyethylene or Nylon, that can be heat set to form the folds of FIG. 7, then expand into the round inflated shape is preferred.
The distal end of balloon inflation shaft 16 is shrunk around, and bonded to an extension of the balloon inflation shaft 60 which extends to a point just within balloon 32. Guidewire shaft 30 lies parallel and adjacent to inflation shaft 16. Reinforcing tubing 62 surrounds both inflation shaft 60 and guidewire shaft 30, with a filler 64 (introduced as detailed below) filling the space between tube 62 and the shafts. Reinforcing tube 62 is preferably formed from a high strength heat shrink tubing that naturally forms a circular cross section when shrunk while pressurized, such as polyethylene. The proximal end of balloon 32 is bonded to the exterior of reinforcing tubing 62 by a layer 66 of adhesive, such as a visible light or ultraviolet light curable epoxy, cyanoacrylate or a heat shrink bond. The distal end of balloon 32 is also bonded to guidewire shaft 30 by a layer of adhesive 66 or a heat shrink bond.
The distal end 68 of inner shaft 60 is closed by melting, with the reinforcing tubing 62 thereover. A skived out notch is cut through the reinforcing tubing 62 and inflation shaft 60 adjacent to distal end 68 to provide for fluid communication between the balloon inflation lumen 58 and the interior of balloon 32.
The distal end of stiffening wire 22 extends through the extended balloon inflation lumen within inner shaft 60. When fully inserted, stiffening wire 22 encounters the closed end of tubes 60 and 62 at 68, which provides a positive stop for full insertion, enables force transmission and prevents inadvertent excessive insertion and/or damage to the interior of balloon 32.
The distal end of stiffening wire 22 can be withdrawn any desired distance, corresponding to the distance between stop ring 54 when handle 52 abuts cap 48 and stop ring 54 when withdrawn into contact with seal 50, as seen in FIG. 3.
Preferably, marker bands 72 are provided at suitable locations within balloon 32 and at predetermined locations along balloon inflation shaft 16. Marker bands 72 are formed from any suitable radio opaque material so that their positions can be clearly seen by X-ray fluoroscopy during catheter insertion. Typical such materials include gold, iridium, platinum and mixtures or alloys thereof.
As mentioned above, in the past when a guidewire shaft and a balloon inflation shaft were bonded together to provide a short guide wire shaft alongside the balloon inflation shaft, the assembly had an oval or elliptical cross section. This shape resulted in problems in inserting the catheter and in bonding such an elliptical assembly cross section to the optimally circular balloon.
An ideal generally circular cross section, as seen in FIG. 6, can be produced by the method schematically illustrated in FIG. 8 and in the block diagram of FIG. 9.
Initially, as seen in FIG. 8 and per block 80 of the flow diagram of FIG. 9, release-coated wire mandrels 74 and 76 (typically Parylene coated stainless steel wires) are inserted into the tube that will become the guidewire shaft 30 and into a mid-distal tube assembly that will become the distal end of balloon inflation shaft 16 and the inner shaft, respectively. Guide wire shaft 30 and the mid/distal assembly are then positioned in the desired overlapping relationship, block 82.
A suitable filler material strip 64 is then inserted between the two shafts, block 84. Any suitable filler material, such as polyethylene, that will melt at a temperature below a temperature at which any of the other components would degrade may be used. While filler strip 64 may have any suitable configuration, a strip cut lengthwise from a piece of tubing, typically about a quarter-round cut from a 0.023 in. outside diameter, 0.0035 in. wall thickness tube, having a crescent-like cross section, is preferred for ease of assembly.
Reinforcing tubing 62 is then slipped over the resulting assembly (guidewire shaft 30 and balloon inflation shaft 60), block 86. Tubing 62 should be a heat shrink material that will shrink at a temperature just above the melting temperature of filler strip 64. Typically, reinforcing tube 62 may be formed from polyethylene or nylon As tubing 62 shrinks, block 88, the assembly takes on a generally oval cross section.
A reshaping tube 78 (as seen in FIG. 8) of a stiff material that naturally assumes a circular cross section is forced over the assembly, (guidewire shaft 30 and balloon inflation shaft 60), and heat shrunk, (see block 90) sufficiently tight to force the assembly into a round configuration. For the purposes of this application, "stiff" means having sufficient stiffness to return to, or remain in, a substantially circular cross section when filled with a molten liquid at just above its melting temperature. While any suitable material may be used for reshaping tube 78, tetrafluroethylene is preferred because of its heat shrinkability, low friction and non-bondable characteristics. In some cases, this tube will produce a sufficiently round shape to the assembly. In that case, the assembly is cooled, block 92, and reshaping tube 78 is removed. In order to produce a more precisely circular cross section in the assembly, after partial cooling, the original reshaping tube 78 can be removed and a smaller diameter reshaping tube can be emplaced, block 94. The smaller diameter reshaping tube is then heat shrunk, cooled and removed, block 96. The resulting substantially round assembly is more easily passed along a body vessel and when bonded to a balloon produces a more uniformly round inflated balloon.
While certain specific relationships, materials and other parameters have been detailed in the above description of preferred embodiments, those can be varied, where suitable, with similar results. Other applications, variations and ramifications of the present invention will occur to those skilled in the art upon reading the present disclosure. Those are intended to be included within the scope of this invention as defined in the appended claims.
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A dilation catheter having a balloon inflation shaft with an inflation lumen into which a stiffening wire extends and a guidewire shaft having a guide wire lumen adjacent to the balloon. The stiffening wire includes at least two stepped diameter reductions along its length to vary stiffness from a stiff proximal end providing improved pushability to a less stiff distal end providing improved trackability. A manifold at the inflation shaft proximal end includes a handle for adjusting the distance the stiffening wire extends into the inflation lumen to allow stiffness to be optimized. The handle includes a tubular flange frictionally engaging the manifold to prevent inadvertent handle movement. The balloon inflation shaft and guidewire shafts are bonded together in a manner producing an assembly having a circular cross section for improved connection to a circular balloon and improved catheter performance.
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This is a division of application Ser. No. 07/177,085, filed Apr. 4, 1988, now U.S. Pat. No. 4,838,074.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a steering torque detecting device used for a motor-driven power steering system installed in, for instance, an automobile.
2. Discussion of the Background
There has been known a steering torque detecting device of such a type that a steering shaft is divided into an input shaft and an output shaft, a torsion bar is provided between the input and output shafts to connect them, displacement caused by a twisting force in the torsion bar is converted into displacement in stroke by means of a displacement converting means constituted by gears provided between the input and output shafts, and the displacement in stroke is detected by a stroke type potentiometer.
There has been known another type of detecting device which is so constructed that such displacement in the torsion bar is converted into a rotational displacement by means of a displacement converting means constituted by gears, and the rotational displacement is detected by a rotation type potentiometer. Thus, a quantity of torque detected is used to rotate a motor for steering operation so as to correspond to the detected quantity.
Thus, in the conventional steering torque detecting device utilizing the displacement converting means formed of the gears to convert the displacement in torsion into the displacement in stroke or the displacement in rotation, there is a disadvantage that the entire structure is complicated and is large-sized.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a steering torque detecting device having a simple structure, and which is light weight and of a small size.
The foregoing and the other objects of the present invention have been attained by providing a steering torque detecting device which comprises a steering shaft consisting of an input shaft and an output shaft, a torsion bar for connecting the input shaft with the output shaft, a printed wiring board in a circular plate form which is provided at its one surface with a resistance layer and an output electrode radially spaced apart from the resistance layer, the resistance layer and the output electrode constituting a potentiometer, and which is attached to either the input shaft or the output shaft, a plurality of slip rings which are fixed to the either one shaft and are connected to electrodes formed at both ends of the resistance layer and the output electrodes, a plurality of brushes in contact with the slip rings to receive detection signals, and a slider mounted on the other shaft and having a portion extending in the radial direction of the circular printed wiring board so as to have contacting areas with a small width to the resistance layer and the output electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a longitudinal cross-sectional view of an embodiment of the steering torque detecting device according to the present invention;
FIG. 2 is a front view of an embodiment of the printed wiring board used in the steering torque detecting device according to the present invention;
FIG. 3 is a perspective view of an embodiment of the slider used for the steering torque detecting device as shown in FIG. 1;
FIG. 4 is a front view of another embodiment of the printed wiring board used for the present invention;
FIG. 5 is a perspective view of an embodiment of the zero point slider as well as the slider used for the present invention; and
FIG. 6 is a diagram showing an embodiment of a brush used for the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A reference numeral 1 designates an input shaft and a numeral 2 designates an output shaft, both being in alignment with their axial centers to thereby constitute a steering shaft. A torsion bar 3 is disposed between the input and output shafts. One end of the torsion bar is fitted in a bore 1a formed in the input shaft in its axial direction and fixed by a fixing pin 4, and the other end is forcibly inserted in a bore 2a formed in the output shaft 2 in its axial direction. The other end of the torsion bar may be loosely inserted in the bore 2a and may be fixed by a fixing pin.
A numeral 6 designates a first housing which is supported by a fixed part (not shown) and which in turn supports the input shaft 1 through a bearing 8. Numeral 7 designates a second housing which is connected to the first housing 6 by means of fitting screws 10 and supports the output shaft 2 through a bearing 9.
Numeral 11 designates a slip ring holder made of a resinous material which is firmly connected to the input shaft 1 and is provided with a flange 11a at its one end portion. Numeral 12 designates a plurality of slip rings embedded in the holder 11, each of the slip rings having a connecting line 13 extended on the side of the flange 11a.
Numeral 14 designates a printed wiring board in a circular plate form firmly attached to the flange 11a of the holder 11.
FIG. 2 shows the printed wiring board in detail. The printed wiring board is generally in an annular form and is provided with a cut portion 14a at the inner circumferential portion which allows each of the connecting lines 13 to pass therethrough and a pair of cut portions 14b formed at the outer circumferential portions of an opposing relation to allow determination in position of the printed wiring board. On one surface of the printed wiring board 14, there is formed elements 15 for constituting a potentiometer. Namely, a numeral 15a designates a resistance layer extending in the circumferential direction of the printed wiring board 14, which has one end as an electrode 15b extended in the circumferential direction and the other end as another electrode 15c which opposes the electrode 15b at a radially outer position. An output electrode 15d is provided opposing the resistance layer 15a at a radially inner position.
The printed wiring board 14 is also provided with an amplifying circuit and a regulation circuit (not shown) for the output electrode 15d.
Referring to FIG. 1, a slider 16 is attached to a surface of a fitting ring 17 made of a insulating material which is fitted to the outer periphery of the output shaft 2 and fixed by a fitting screw 18. The slider 16 is so formed as to extend in the radial direction of the printed wiring board 14 so that it electrically contacts with both of the resistance layer 15a and the output electrode 15b, it having contacting areas with a small width to contact with them.
FIG. 3 shows an embodiment of the slider 16 in detail. The slider 16 is made of a thin metallic plate having flexibility, a low frictional coefficient and good electric conductivity. The slider 16 has a radially extending end portion from which a plurality of thin tongue portions as first contacting pieces 16a extend in the circumferential direction of the printed wiring board so that each end of the contacting pieces 16a is in contact with the resistance layer 15a, and another radially and inwardly extending end poriton from which a plurality of thin tongue portions as second contacting pieces 16b extend in the same direction as the first contacting pieces 16a so that each end of the second contacting pieces 16b is in contact with the output electrode 15d.
Turning to FIG. 1, a brush device 19 is formed by a brush holder 20 made of a resinous material and attached to the first housing 6 and a plurality of brushes 21 each made of a thin wire of an alloy having flexibility, a low frictional coefficient and good electric conductivity. Each free end is in slide-contact with each of the slip rings 12 and the rear end is fixed to a terminal block 22 embedded in the brush holder 20. Each of the terminal blocks 22 is connected to drawing lines 24 through each through capacitor 23. The through capacitor 23 is to remove noises resulted in the torque detecting device due to change in the pressure of contact between the brushes 14 and the slip rings 12, the change in the contacting pressure causing change in the resistance of contact whereby external noises are easily taken.
Numeral 25 designates a cover for covering the brush holder 20.
The operation of the torque detecting device of the above-mentioned embodiment will be described.
When a steering wheel is not operated and therefore, when there is no difference in the torque between the input and output shafts 1, 2, there is no displacement in the torsion bar 3. Accordingly, the slider 16 is at the neutral position in its circumferential direction with respect to the resistance layer 15a as the element 15 of the potentiometer, whereby no output results from the potentiometer due to any change of the displacement of the torsion bar.
When the steering wheel is operated, there is produced a difference of torque between the output and input shafts 1, 2, and there appears a displacement of torsion in the torsion bar 3. As a result, the position of contact of the slider 16 relatively changes in the turning direction with respect to the resistance layer 15a in proportion to the quantity of the displacement in the torsion bar, whereby an output signal is produced from the potentiometer in proportion to the quantity of displacement. Depending on the direction of turning of the steering wheel on the left side or the right side, the position of contact of the slider 16 in the circumferential direction of the printed wiring board 14 with respect to the neutral position of the resistance layer 15a is changed on one side or the opposite side. Accordingly, the direction of rotation to be applied to the output shaft 2 is determined depending on a signal detected.
In the above-mentioned embodiment, the slip rings 12 and the printed wiring board 14 are mounted on the input shaft 1, and the slider is mounted on the output shaft 2. However, these parts may be substituted for attachment to the input and output shafts.
Thus, in the above-mentioned embodiment, the printed wiring board provided with the resistance layer and the electrodes which constitute a potentiometer, and the slip rings to take signals from the electrodes to the outside are mounted on either one of the input and output shafts, and the slider is mounted on the other one, the slider extending in the radial direction to contact with the resistance layer and the output electrode of the printed wiring board. Accordingly, the entire construction of a signal detecting assembly for the steering torque detecting device can be simple and small-sized.
FIGS. 4 and 5 show another embodiment of the steering torque detecting device according to the present invention. In FIGS. 4 and 5, the same reference numerals as in FIGS. 1-3 designate the same or corresponding parts, and therefore, description of these parts is omitted.
As shown in FIG. 4, a zero point detecting unit 26 is formed at a symmetric position to the potentiometer 15 with respect to an X--X line. Namely, the zero point detecting unit 26 is formed in a space remaining unutilized on the surface of the printed wiring board 14. The zero point detecting unit 26 comprises a zero point electrode 26a having a circumferentially extending end, a zero point contact part 26b having a small width extended radially and inwardly on the printed wiring board 14, and a corresponding electrode 26c which is formed at the inner circumferential side to face the zero point contact part 26b with a space. The electrode 26a and the corresponding electrode 26c are respectively connected to the slip rings 12 through the connecting lines 13.
FIG. 5 shows a zero point slider 27 made of the same material as the slider 16 which is formed on the surface of the fitting ring 17 on which the slider 16, as described with reference to FIG. 3 is formed. The zero point slider 27 has a portion in which a plurality of contacting pieces 27a are extended in the circumferential direction of the fitting ring 17 so that each end of the contacting pieces 27a is in contact with the zero point contact part 26b when the fitting ring 17 and the printed wiring board 14 are assembled to the steering torque detecting device. The zero point slider 27 has another portion in which a plurality of contacting pieces 27b are formed to extend in the same direction as the contacting pieces 27a so that each end of the contacting pieces 27b is in contact with the corresponding electrode 26c when the fitting ring 17 and the printed wiring board 14 are assembled.
The position of the zero point slider 27 is so determined as to be in contact with the zero point contact part 26b only when the difference in the torque between the input and output shafts 1, 2 is zero, namely, when there is no displacement in the torsion bar 3. When a slight difference in torque is resulted so that displacement in rotation at a small rotation angle a is produced, the slider 27 is deviated from the zero point contact part 26b, whereby a zero point detecting signal indicating that there is a torque in the steering wheel is interrupted. Accordingly, the width of the zero point contact part 26b is made small as possible in order to increase accuracy to detect the zero point. Namely, it is desirable that the zero point contact part 26b should be in a linear form in the radial direction.
In the operation of the above-mentioned embodiment, when the steering wheel is not operated, and therfore there is no difference in torque between the input and output shafts 1, 2, any displacement of torsion is produced in the torsion bar 3. Accordingly, the slider 16 is at the neutral (middle) position in the circumferential direction of the printed wiring board with respect to the resistance layer 15a as an element of the potentiometer 15, and there is no output from the potentiometer.
Since the zero point slider 27 extends to contact both the zero point contact part 26b and the corresponding electrode 26c, and a signal indicating that there is conduction between the both elements 26b and 26c is produced and is detected as the torque zero point for the steering wheel. The signal of the torque zero point prevents the motor from driving the steering wheel.
When the steering wheel is operated to cause the difference in torque between the input and output shafts 1, 2, is produced a displacement in the torsion bar 3. Then, the position of the slider 16 in contact with the resistance layer 15a is relatively changed by a rotating movement in proportion to a quantity of displacement in the torsion bar, whereby an output signal is generated from the potentiometer in proportion to the quantity of displacement.
By the change in position of the slider 16, the zero point slider 27 becomes out of contact with the zero point contact part 26b due to the relative movement in the circumferential direction, whereby electrically conducting condition between the corresponding electrode 27c and the slider 27 is broken; thus, a steering torque is detected. At the same time, the condition for preventing the motor from driving for power steering is released.
Thus, the position of contact of the slider 16 with respect to the neutral position to the resistance layer 15a is changed in the circumferential direction by the operation of the steering wheel either on the left hand or the right hand, whereby the direction of rotation to the output shaft 2 is determined by the change in the value of the detected signal.
The above-mentioned embodiment eliminates a problem in that as seen in an analogical detecting method in the conventional potentiometer, resistance in the resistance layer is not always uniform over its entire area because the ambient temperature changes, this causing zero point drifting thereby resulting in inconsistency between the zero point in the steering torque and the zero point of the torque detecting device.
Further, in the above-mentioned embodiment, the zero point slider extending in the radial direction to contact the zero point contact part of the zero point electrode and the corresponding electrode is mounted on either the input shaft or the output shaft as well as the slider which spans the resistance layer and the output electrode on the printed wiring board. Accordingly, the entire construction of the torque detecting assembly becomes simple, small-sized and reduces the weight. In addition, correct detection of the zero point in steering torque can be obtained to thereby improve performance of the power steering system.
FIG. 6 is a front view of an embodiment of the brush used for the torque detecting device according to the present invention.
Reference numeral 22 designates a terminal block attached to the brush holder 20 as shown in FIG. 1, and numeral 21 designates a brush made of nickel or a nickel series alloy and is formed by a pair of elongated bodies 21a, 21b. Each one end of the elongated bodies 21a, 21b is electrically and mechanically connected to the terminal block 22 and the free ends of them are in contact with a slip ring so as to hold it therebetween.
The reason why the nickel or the nickel series alloy is used for the brush is to eliminate drawbacks in a conventional flat-plate-like brush made of phosphor bronze which is generally used for steering torque detecting devices: (a) it rapidly wears because it contains copper, (b) manufacturing cost is high, (c) a uniform pressure of contact can not be provided, (d) it has a low durability, and (e) therefore, reliability in its performance is low.
In the brush 21 consisting of two thin elongated bodies 21a, 21b which hold the slip ring 12 rotated with the input shaft 1 therebetween, even when one elongated brush element becomes faulty due to wear in used, the other brush element normally operates to detect signals.
The pressure of contact of the brush 21 to the slip ring 12 can be adjusted, for instance, by changing the distance between the terminal block 22 fixing the brush elements 21a, 21b and the slip ring 12.
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A steering torque detecting device includes a steering shaft consisting of an input shaft and an output shaft, a torsion bar provided between the input shaft and the output shaft, a torque detecting unit for converting a quantity of torsion produced in the torsion bar into an electric output, an electricity collecting unit including slip rings and brushes which takes the electric output and supplies an electric power from an outer power source, bearings for supporting the input and output shaft on the same axial line, and a housing supporting the bearings, a printed wiring board in a circular plate form which is provided at its one surface with a resistance layer and an output electrode radially spaced apart from the resistance layer, the resistance layer and the output electrode constituting a potentiometer, and a slider having a portion extending in the radial direction of the circular printed wiring board so as to have contacting areas with a small width to the resistance layer and the output electrode.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/436,841 entitled GARMENT HAVING INTEGRATED PERSPIRATION BARRIERS filed Jan. 27, 2011, the disclosure of which is incorporated herein by reference.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Technical Field of the Invention
[0004] The present invention relates generally to wearing apparel and, more particularly, to a garment or undergarment (e.g., a T-shirt) which is provided with integrated multi-layer perspiration barriers uniquely configured to provide high levels of evaporative cooling and moisture vapor transmission.
[0005] 2. Description of the Related Art
[0006] As is known in the medical field, hyperhidrosis is a condition characterized by abnormally increased perspiration, in excess of that required for the regulation of body temperature. Hyperhidrosis can either be generalized or localized to specific parts of the body. Hands, feet, armpits and the groin area are among the most active regions of perspiration due to the relatively high concentration of sweat glands.
[0007] Of the various manifestations of hyperhidrosis, one of the most problematic for many individuals is axillary hyperhidrosis, or excessive underarm sweating. Because of the various stigmas that society has perpetuated about people who sweat excessively, as well as the unsightly appearance of excessive underarm perspiration, sufferers of axillary hyperhidrosis are often reluctant to wear certain fabrics or colors which exacerbate the appearance of the perspiration. In addition, these sufferers are often compelled to leave jackets, sweaters, sport coats or other garments on to their discomfort, solely for the shielding effect provided by these outer garments. Moreover, in extreme circumstances, sufferers may resort to actually bringing changes of clothes with them to work or other events, assuming that the level of perspiration in a worn garment will reach a level of severity which mandates a disruptive, yet necessary change of clothes.
[0008] For the treatment of axillary hyperhidrosis, the aluminum chloride used in regular antiperspirants is typically insufficient, with sufferers often needing solutions with higher concentrations to effectively treat the symptoms of the condition. However, one of the major side effects of antiperspirant solutions which are adaptive to facilitate the treatment of axillary hyperhidrosis is a high level of irritation to the skin. Though surgical options are available for the treatment of axillary hyperhidrosis, including sweat gland removal or destruction, many sufferers seek treatment options which do not require a surgical procedure due to the cost of the procedure, the risks associated therewith, or other factors.
[0009] In recognition of the social difficulties experienced by many axillary hyperhidrosis sufferers and the reluctance of many of these sufferers to seek medical or surgical intervention for the treatment of their condition, there has been developed in the prior art various undergarments with permanently attached perspiration shielding which are adapted to protect outer clothing for underarm perspiration. Such undergarments are described, for example, in U.S. Pat. No. 6,591,425 to Zellers, and in U.S. Patent Publication Nos. 2006/0168704 to Mayer, et al, and 2008/0086791 to Kirkwood Samuels, et al. Though the undergarments described in these and other references provide the general effect of protecting a wearer's outer clothing from underarm perspiration, they possess certain deficiencies which detract from the overall utility. For example, in certain ones of these prior art undergarments, the perspiration shield includes a waterproof layer and is placed proximate the wearer's skin in the underarm area, thus actually causing increased levels of perspiration attributable to the shield acting as a barrier to air flow, in addition to causing discomfort to the wearer. Additionally, in certain ones of these prior art garments, the layered construction of the perspiration shields included therein is not adapted to facilitate cooling air flow via a billowing effect, or to promote wearer comfort.
[0010] The present invention addresses and overcomes the deficiencies highlighted above by providing a garment or undergarment (e.g., a T-shirt) which is provided with integrated multi-layer perspiration barriers uniquely configured to provide high levels of evaporative cooling and moisture vapor transmission. These, as well as other features and advantages of the present invention will be described in more detail below.
BRIEF SUMMARY OF THE INVENTION
[0011] In accordance with the present invention, there is provided a garment or undergarment (e.g., a T-shirt) which is provided with integrated multi-layer perspiration barriers uniquely configured to provide high levels of evaporative cooling and moisture vapor transmission. More particularly, in the garment construction in accordance with the present invention, the perspiration barriers are integrated into the sleeve and torso portions of the garment such that such perspiration barriers actually define the underarm portions thereof. This is in contrast to prior art garment constructions wherein the perspiration shields are attached to the interior or exterior surfaces of the underarm portions of an existing garment, as opposed to the shield themselves defining such underarm portions.
[0012] In addition, each of the perspiration barriers integrated into the garment of the present invention is preferably comprised of four separate layers, each of which has a two-piece or panel construction. The materials of the various layers included in each of the perspiration barriers, the manner in which the layers are stacked upon and attached to each other, and the manner in which the stacked layers of joined panel pieces forming each perspiration barrier are integrated into the garment are specifically adapted to collectively promote evaporative cooling and a vapor transmission effect which provides superior perspiration absorption and evaporation, in addition to enhanced user comfort.
[0013] The present invention is best understood by reference to the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These, as well as other features of the present invention, will become more apparent upon reference to the drawings wherein:
[0015] FIG. 1 is a front elevational view of an undergarment constructed in accordance with the present invention;
[0016] FIG. 2 is a plan view of one of the multi-layer perspiration barriers integrated into the undergarment of the present invention, as viewed from the perspective of the view angle 2 shown in FIG. 1 ;
[0017] FIG. 3 is a partially exploded view of one of the layers included in each of the multi-layer perspiration barriers integrated into the undergarment of the present invention, depicting the two-piece primary construction thereof; and
[0018] FIG. 4 is an exploded view of one of the multi-layer perspiration barriers integrated into the undergarment of the present invention, depicting the various layers included therein.
[0019] Common reference numerals are used throughout the drawings and detailed description to indicate like elements.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring now to the drawings wherein the showings are for purposes of illustrating a preferred embodiment of the present invention only, and not for purposes of limiting the same, FIGS. 1 and 2 depict a garment 10 constructed in accordance with the present invention. In an exemplary embodiment, the garment 10 is an undergarment and, more particularly, a T-shirt. In this regard, the garment 10 comprises a torso portion 12 , one end of which includes an opening 14 therein to accommodate the head and neck of a wearer. In addition to the torso portion 12 , the garment 10 includes an opposed pair of sleeve portions 16 which are attached to the torso portion 12 and are sized to cover the upper arms of the wearer of the garment 10 . As further seen in FIGS. 1 and 2 , each of the sleeves 16 defines a distal rim or end 18 .
[0021] The garment 10 further comprises an identically configured pair of perspiration barriers 20 which are integrated into the remainder of the garment 10 in a manner which will be described in more detail below. As seen in FIG. 4 , each of the perspiration barriers 20 preferably comprises a plurality (e.g., four) stacked layers. Additionally, as seen in FIG. 3 , each of these layers has a two-piece construction, comprising a sleeve panel piece 22 and a torso panel piece 24 which are preferably sewn to each other as also described in more detail below. As further seen in FIG. 3 , the sleeve panel piece 22 of each layer has a generally trapezoidal configuration, with the torso panel piece 24 having a generally semi-circular configuration.
[0022] As indicated above, each perspiration barrier 20 is provided with a four-layer construction. More particularly, as seen in FIG. 4 , each perspiration barrier comprise a first layer 26 which will normally be in direct contact with the skin in the underarm of the wearer of the garment 10 . As such, the first layer 26 is preferably fabricated from 100% cotton to provide an increased level of comfort to the wearer. The use cotton material of the first layer 26 is advantageous due to the ability of odor molecules emanating from the wearer's skin to easily break away from the cotton fibers, thus combating odor issues. Positioned against the first layer 26 is a second layer 28 which is preferably a terry-cloth material fabricated from 80%-20% cotton/polyester blend. As will also be discussed in more detail below, the “loop” design of the terry-cloth material used for the second layer 28 facilitates better airflow through the fully fabricated perspiration barrier 20 , thus enhancing an evaporative cooling effect provided thereby.
[0023] In addition to the first and second layers 26 , 28 , each of the perspiration barriers comprises a third layer 30 which is positioned against the second layer 28 such that the second layer 28 is effectively oriented between the first and third layers 26 , 30 . The third layer 30 is preferably a hydrophilic breathable film which is fabricated from polyurethane and bonded by a finely dispersed adhesive dot pattern to the second layer 28 . Positioned against the third layer 30 is a fourth layer 32 , the third layer 30 thus being oriented between the second and fourth layers 28 , 32 . The fourth layer 32 is preferably made of the same material as the torso and sleeve portions 12 , 16 of the garment 10 (e.g., a cotton material) for aesthetic consistency when the perspiration barriers 20 are integrated therein. In this regard, whereas the first layer 26 defines the innermost surface of each perspiration barrier 20 in the completed garment 10 which will directly contact the skin of the wearer thereof, the fourth layer 32 defines the outermost surface of each perspiration barrier 20 in the completed garment 10 which is visually exposed when the same is being worn by the wearer.
[0024] As indicated above each of the first, second, third and fourth layers 26 , 28 , 30 , 32 of each of the perspiration barriers 20 comprises a pair of the sleeve and torso panel pieces 22 , 24 which are joined (e.g. sewn) to each other. More particularly, in fabricating each of the first and fourth layers 26 , 32 , a portion of the sleeve panel piece 22 extending along the peripheral base edge segment thereof of greatest length is joined to a portion of the torso panel piece 24 extending along the linear, non-arcuate peripheral edge segment thereof by an elongate stitch 34 which defines a foldable crease between the sleeve and torso panel pieces 22 , 24 .
[0025] However, in fabricating the second and third layers 28 , 30 , the sleeve panel pieces 22 of such second and third layers 28 , 30 are initially bonded to each other in the aforementioned manner, as are the torso panel pieces 24 thereof. Thereafter, the bonded sleeve panel pieces 22 of the second and third layers 28 , 30 are sewn to the bonded torso panel pieces 24 thereof by a single, elongate stitch 34 . As described above in relation to the first and fourth layers 26 , 32 , the stitch 34 joining the bonded sleeve panel pieces 22 of the second and third layers 28 , 30 to the bonded torso panel pieces 24 thereof extends along the peripheral base edge segments of the bonded sleeve panel pieces 22 of greatest length and the linear, non-arcuate peripheral edge segments of the bonded torso panel pieces 24 , such stitch 34 also defining a foldable crease therebetween. Advantageously, the materials from which the second and third layers 28 , 30 are fabricated, in concert with the manner in which they are attached to each other, enhances vapor transmission and breathability between the adjacent second and third layers 28 , 30 in each of the fully fabricated perspiration barriers 20 .
[0026] Once the various corresponding pairs of sleeve and torso panel pieces 22 , 24 have been sewn to each other in the aforementioned manner, the resultant first, second, third and fourth layers 26 , 28 , 30 , 32 are stacked upon each other such that the first layer 26 is positioned against the second layer 28 , and the fourth layer 32 is positioned against the third layer 30 . As indicated above, each perspiration barrier 20 of the garment 10 comprises the first, second, third and fourth layers 26 , 28 , 30 , 32 as stacked upon each other in this particular sequence. Once each perspiration barrier 20 has been fabricated or assembled in the aforementioned manner, it is sewn into the torso portion 12 and a corresponding sleeve portion 16 of the garment 10 using a continuous overlock stitch which extends solely along the peripheral edge thereof. It is contemplated that this peripheral overlock stitch will be covered by a continuous cover stitch 36 to provide a more desirable appearance to the garment 10 .
[0027] Additionally, as best seen in FIG. 2 , each perspiration barrier 20 is preferably orientated relative to the remainder of the garment 10 such that the peripheral base edge segments of shortest length within the stacked sleeve panel pieces 22 of each perspiration barrier 20 extend along the distal end 18 of a respective one of the sleeve portions 16 . Extending each perspiration barrier 20 to the distal end 18 of a respective one of the sleeve portions 16 helps reduce any occurrences of undesirable dripping of perspiration down the wearer's arm when the garment 10 is being worn. However, those of ordinary skill in the art will recognize that each perspiration barrier 20 may alternatively be orientated within the remainder of the garment 10 such that a gap or space of a prescribed width separates each perspiration barrier 20 from the distal end 18 of a corresponding sleeve portion 16 .
[0028] Advantageously, the manner in which the perspiration barriers 20 are assembled, and in turn integrated into the remainder of the garment 10 , provides enhanced evaporative cooling and moisture vapor transmission attributable to a billowing effect in each of the perspiration barriers 20 . This billowing effect, and the resultant evaporative cooling and moisture vapor transmission process, also serves to decrease perspiration by lowering body temperature. Such billowing effect is achieved by the particulars of the construction of each of the perspiration barriers 20 , and is enhanced by the minimal amount of stitching which extends through areas other than the peripheral portions thereof (thereby reducing the number of interiorly located needle holes). In this regard, as previously explained, within each perspiration barrier 20 , the only stitching that extends through the interior thereof are the three separate, elongate stitches 34 that are used to join the sleeve and torso panel pieces 22 , 24 of the first, second, third and fourth layers 26 , 28 , 30 , 32 to each other. These stitches 34 within each perspiration barrier 20 provide the advantage of collectively creating a crease which allows the wearer of the garment 10 to more easily lift and lower his or her arms without undue resistance by the perspiration barriers 20 , while further preventing an excessive amount of noise being generated by the arm lifting and lowering process. Moreover, since the stitches 34 within each perspiration barrier 20 are only generally aligned with each other and do not give rise to the creation of continuous needle holes which span through each the first, second, third and fourth layers 26 , 28 , 30 , 32 , there is a significantly reduced potential for moisture or perspiration to travel along the stitches 34 and through the needle holes in a manner comprising the integrity of each perspiration barrier 20 .
[0029] The “perimeter only” stitching used to facilitate the attachment of each of the fully fabricated perspiration barriers 20 to the remainder of the garment 10 allows outside air to be drawn into and between the first and second layers 26 , 28 , as well as the third and fourth layers 30 , 32 , of each of the perspiration barriers 20 . At the same time, the stitches 34 of each of the perspiration barriers 20 , due to thereof relative orientations, do not unduly compromise the billowing effect. As a result, as seen in FIG. 4 , moisture produced and emanating from the underarm skin of the wearer is initially transported through the first layer 26 , and into a space or air chamber between the first and second layers 26 , 28 . Such moisture is then channeled through the second layer 28 and is thereafter transported along the molecular chains of the block co-polymer of the third layer 30 to reach equilibrium with the outside atmosphere, which also facilitates the transition of the moisture to a vapor state. As is also shown in FIG. 4 , the vapor which emanates from the third layer 30 in turn flows into the space or air chamber between the third and fourth layers 30 , 32 . As indicated above, the bonding of the third layer 30 to the second layer 28 by the finely disbursed adhesive dot pattern of the third layer 30 allows for better vapor transmission and breathability through such third layer 30 . The vapor within the space between the third and fourth layers 30 , 32 is thereafter released from the perspiration barrier 20 through the exterior fourth layer 32 .
[0030] This disclosure provides an exemplary embodiment of the present invention. The scope of the present invention is not limited by this exemplary embodiment. Numerous variations, whether explicitly provided for by the specification or implied by the specification, such as variations in structure, dimension, type of material and manufacturing process may be implemented by one of skill in the art in view of this disclosure. For example, those of ordinary skill in the art will recognize that the above-described perspiration barriers 20 may be integrated into a garment other than for an undergarment such as a T-shirt. Additionally, some or all of the stitching described above could potentially be substituted with a suitable fabric adhesive.
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In accordance with the present invention, there is provided a garment or undergarment (e.g., a T-shirt) which is provided with integrated multi-layer perspiration barriers uniquely configured to provide high levels of evaporative cooling and moisture vapor transmission. The perspiration barriers are integrated into the sleeve and torso portions of the garment such that such perspiration barriers actually define the underarm portions thereof. Each of the perspiration barriers is preferably comprised of four layers, each of which is formed from two separate panel pieces. The various layers included in each of the perspiration barriers, the manner in which such layers are stacked upon and attached to each other, and the manner in which the layers forming each perspiration barrier are integrated into the garment are specifically adapted to collectively promote evaporative cooling and a vapor transmission effect which provides superior perspiration absorption and evaporation, in addition to enhanced user comfort.
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FIELD OF THE INVENTION
The present invention relates to a trash storage device and more particularly to a trash bin that stores daily trash and makes the transportation of the trash to the curb on pick-up day easier with a wheeled system. The trash bin is designed to protect the trash from animals, allow for ventilation, and to be decorative so as not to be an eyesore next the building in which it is stored. The trash bin can also be customized with decorative panels so as to match or complement the building next to which it is installed.
BACKGROUND OF THE INVENTION
Everyday life includes many chores that need to be done on a recurring basis. Home and business owner's daily storage and the task of taking out the garbage can be particularly challenging. In most areas, homeowners need to take the trash cans to the curb for pickup by the municipal or private garbage collectors at least once and most often several times a week. This can mean carrying, or rolling several individual trash cans to the front curb, which can be anywhere from ten feet away from the house to several hundred feet away from the house.
For many homeowners this task is done early in the morning, rather than the night before pickup because animals, such as raccoons, fox, deer and the like often get into the trash cans and throw trash all over the lawn while looking for food. Currently, one of the only alternatives currently available to prevent waking up to a lawn full of trash is to take the trashcans to the curb the morning of pickup. Often, taking the trashcans to the curb the morning of pickup usually means it is done when the homeowner is dressed and rushing to work.
Individual trashcans with wheels are easier to get to the curb than non-wheeled trashcans since they do not have to be carried. However, the wheeled trash cans do very little to protect the cans from being toppled and opened by animals if left outside overnight. Some trash cans use the handles from which they are pulled to lock the cover of the trash can closed. Although a good concept, the handles are usually easily opened by determined rodents looking for their next meal and therefore are of little help.
Another problem associated with using individual trash cans is the fact that the homeowner can transport only one wheeled trash can at a time to the curb. Therefore, it is often necessary for the homeowner to make several trips to complete the task. Making several trips can be time consuming and depending on the distance and incline from the house to the curb can be exhausting. This fact alone makes the option of using individual trashcans less attractive than the trash cart of the present invention.
Between the assigned days for garbage pick up is the ongoing problem of daily garbage storage. Many people store garbage in their garage until pick up day. This often causes a space issue with cars and/or other items being stored as well as odors permeating the structure. Others opt to keep their garage outside using a multiple of solutions in order to ward off animals. This includes ropes and bungee cords attempting to secure the garbage and/or adding weighted objects to the top of the trash cans. Each time a homeowner adds trash, they must re-secure the trash can covers.
There are devices available today that are used to transport trash cans to the curb for pick up but these devices are not enclosed, leaving the trash cans/garbage exposed to animals. Since the trash cans are not protected against animals, these devices must be stored inside and therefore are only marginally better than individual wheeled trash cans and do not solve the problem of garage space.
Another problem faced by homeowners with trashcan transportation devices and trashcans available on the market today is that they are often unattractive. In stark contrast, the trash bin/cart of the present invention has decorative panels that can be used to either match or complement the building next to which it is stored.
Finally many of the transportation carts available on the market today are made of flimsy tube piping making the overall structure un-sturdy. Therefore in view of the foregoing shortcomings, what is needed is a trash bin that is sturdy enough to allow a homeowner to store their daily garbage, move the garbage to the curb easily, and store the garbage between pickup days without worrying about the animals getting into the trash. Additionally, the trash bin/cart system is decorative so as to complement a building when stored on the side of the house or left at the curb for pickup. The present invention contains all of these attributes and more and solves the problems and shortcomings described above.
SUMMARY OF THE INVENTION
The present invention is directed to a trash bin and cart system comprising a trash bin having a front panel, a back panel, a left side panel, a right side panel, a top panel, and a bottom panel in communication to form an enclosure. The trash bin also contains at least one hinge that attaches the top panel of the trash bin to the back panel of the bin so that the top panel moves freely away from the back panel to reveal an interior portion of the trash bin. The trash bin system also includes a trash cart configured so as to fit within the trash bin. The trash cart comprises a wheel base having at least one axle connected to the trash cart wherein the axle has at least one wheel arranged so that the trash cart is able to move freely about. In alternative embodiments the trash cart can have two, three, four or more wheels arranged so as to distribute the weight of the trash cans and to optimize the maneuverability of the cart.
The structure may also have a front panel having at least one hinge means that is configured so as to be in direct communication with at least one door, the door being contiguous with the front panel of the trash bin and the when closed and exposes an interior portion of the trash bin when opened. The opening created by opening the door being large enough for the trash cart to exit and re-enter for storage into the trash bin. In an alternative embodiment of the trash bin, the trash bin is configured to have two doors on a hinge means that open in opposite directions to expose the interior of the trash bin. The trash bin system can be equipped with a ramp so as to allow for easy exit and re-entry of the trash cart.
Another embodiment of the invention is directed to a trash bin and cart system kit comprising a front panel, a back panel, a left side panel and a right side panel, a top panel, and a bottom panel. At least one hinge means for attaching the back panel and the top panel and at least one hinge means for attaching at least one door to the front panel so that when one or more of the doors are opened an interior portion large enough for a cart to pass through is exposed.
In other words, the trash cart in the kit is configured so as to fit within the trash bin and comprises a wheel base having at least one axle connected to the trash cart. The axle connected to the wheel base has at least one wheel, but may have two, three, four or more wheels attached. The wheel(s) arranged so that the trash cart is able to freely move about on the wheel base.
The kit is also equipped with materials to customize the trash bin. For example the kit may be equipped with attachable decorative panels that are configured so as to be attachable to the front panel, the back panel, the left side panel, the right side panel, and the top panel of the trash bin. Since the trash bin is designed to be stationary the trash bin can be customized to blend and/or match the structure next to which is stored.
The kit also include fasteners to connect the front panel, the back panel, the left side panel, the right side panel, and the top panel of the trash bin together and the decorative panels to the front panel, the back panel, the left side panel, the right side panel, and the top panel. The kit is easier to ship than a version that is already assembled
In still another embodiment the trash bin the trash cart is configured to have at least one wheeled axle located at the back portion of the bottom panel of the trash cart and at least one leg of the same height as the wheel is attached to the front portion of the bottom panel of the trash cart so that the trash cart is leveled. The wheeled axle makes transporting of trash cans in the trash cart easier for the user. In an alternative embodiment of the invention, a second wheeled axle is attached to the front bottom panel of the trash cart replacing the leg previously mentioned. The four-wheeled trash cart is designed to handle more weight than the single axel version.
Both the single and multiple axel version of the present invention may be equipped with a steering mechanism that will allow the user to maneuver the trash cart to the curb on pick-up day and back to the storage place once the trash is collected.
On the outside portion of the front panel, the back panel, the left side panel, the right side panel, and the top panel is an attaching means for attaching decorative panels. The kit can have several different decorative panels that can make the enclosure complement the building in which it belongs or an ornate structure such as plastic overlay design (such as basket weave) wrought iron design, stucco, wood frame, vinyl shingles, aluminum siding or the like to give it a unique look.
The top panel can be hinged to the back panel so that it can open to reveal the trashcans stored inside. In one embodiment of the trash cart the top panel of the trash cart can be split in more than one portion, preferable two portions. Each of the aforementioned portions is configured so that they can be hinged to the back panel so as to open together or independently. The front panel can be designed so as to have a single or double doors hinged so that the door(s) can be opened to reveal the trash cans stored with the enclosure.
The kit may also contain illustrative instructions that describe how the described components fit together. These embodiments as well as others are further described in the drawings and the Detailed Description of the drawings immediately following this section.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 :
( 05 ) a full view of the trash bin and trash cart inside cart with doors and top lids closed. ( 10 ) top panel ( 15 ) top hinges ( 20 ) top handle ( 25 ) right side panel ( 30 ) steering means ( 35 ) front axle ( 40 ) front wheel ( 45 ) rear axle ( 50 ) rear wheel ( 55 ) front door hinges ( 60 ) left front door ( 65 ) right front door ( 70 ) trash can ( 75 ) front door latch ( 80 ) front door handle ( 85 ) side latch ( 90 ) separator panel ( 95 ) left side panel
FIG. 2 :
( 100 ) a full view of the trash cart ( 105 ) side panel ( 110 ) handle ( 115 ) latch spring ( 120 ) latch ( 125 ) separator ( 130 ) flatbed of cart ( 135 ) rear axle ( 140 ) front axle ( 145 ) front wheel ( 150 ) hooks for carrying bulky material ( 155 ) rear wheel
FIG. 3 :
( 200 ) full view of alternative embodiment of the trash cart ( 205 ) steering means ( 210 ) front axle ( 215 ) side lip ( 220 ) front wheel ( 225 ) rear axle ( 230 ) rear wheel ( 235 ) flatbed ( 240 ) handle ( 245 ) separator panel ( 250 ) front lip ( 255 ) back lip
FIG. 4 :
( 300 ) enclosed alternative trash cart in trash bin ( 305 ) side panel door ( 310 ) hinges ( 315 ) pull handle ( 320 ) latch spring ( 325 ) latch (male) ( 330 ) latch (female) ( 335 ) front door lock ( 340 ) ramp ( 345 ) top panel ( 350 ) top panel handle ( 355 ) front handle ( 360 ) front axle ( 365 ) front wheel ( 370 ) rear axle ( 375 ) rear wheel ( 380 ) flat bed ( 385 ) front door
FIG. 5
( 400 ) a schematic of the kit assembly.
( 405 ) top panel
( 410 ) top panel hinges
( 415 ) separator panel
( 420 ) front panel handle
( 425 ) back panel
( 430 ) right side panel
( 435 ) left side panel
( 440 ) bottom panel
( 445 ) separator panel
( 450 ) wheel
( 455 ) axle
( 460 ) steering means
( 465 ) structural supports
( 470 ) left front door
( 475 ) right front door
( 480 ) steering connection
( 485 ) instructions
( 490 ) fasteners and bolts
( 495 ) flat bed
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a trash bin and cart system designed to be functional but yet decorative. The cart of the cart portion of the present invention is designed to make the chore of “taking out the trash out” easy without compromising the appearance outside of the house. In other words, the trash cart of the present invention can be filled with trash bins and stored within the trash bin until the day for garbage pickup. In the trash bin, the trash cans are protected from the weather and the animals without unsightly trash cans being stored on the side of the house or in the garage.
The trash bin and cart system is designed to provide a decorative and easy way to store trash outside the house while preventing egress into the trashcans by animals. These and other features are shown in FIGS. 1-5 of the present document and are further described below.
FIG. 1 shows a cut-away schematic view of the trash bin and trash cart system with the doors and the top of the trash bin closed ( 05 ). The trash bin is transparent to show the details of the inside of the trash bin. The trash bin comprises a top panel ( 10 ), a back panel ( 96 ), a right side panel ( 25 ), and a left side panel ( 95 ) that is configured to make a shelter. The top panel ( 10 ) is removably attached to the back panel ( 96 ) by hinges ( 15 ) and is capable of being lifted away from the rest of the trash bin to reveal the inside of the trash cart.
The trash bin also has a left front door ( 60 ) and a right front door ( 65 ) that is connected to at least a portion of the side frames of the trash bin by front door hinges ( 55 ). The front door hinges ( 55 ) allows the front door panels ( 60 , 65 ) to swing open and reveal the inside of the trash bin ( 05 ). The left side panel ( 95 ) can be attached to the back panel ( 96 ) so that the left side panel ( 95 ) can swing open to reveal the inside of the trash bin. Attached to the left side panel ( 95 ) is a side latch system ( 85 ) which has a latch positioned on the side panel and an insert that the latch fits in on either the frame and/or the front panel that secures the side panel closed. Similarly, the front panel doors can be secured close with a front door latch ( 75 ) and the top panels may be secured closed using a latch system. All latches should be child and animal proof so as to keep the trash bin secured when closed.
Inside the trash bin ( 05 ) is a trash cart ( 98 ) that comprises a steering means ( 30 ) in communication with at least one of the front or rear axles ( 35 , 45 ). The steering means ( 25 ) can be as simple as a handle attached to the side panel or a pull stick or as complex as steering means with a braking system. The cart also comprises front wheels ( 40 ) and rear wheels ( 50 ) attached to the front and rear axles ( 35 , 45 ) and to wheel supports ( 99 ). The wheel supports ( 99 ) attach to either the wheels directly or to the axle in order to support the weight placed on the platform of the cart ( 98 ). The cart ( 98 ) is designed to freely move about once it is removed from the trash bin.
The trash cart ( 99 ) may also be equipped with a separator panel that separates and prevents the trash cans ( 70 ) from moving about on the cart ( 98 ). In addition, the panels that may be opened may be equipped with handles to do so. The trash bin ( 05 ) may be equipped with a floor panel or may use the pavement in which it is placed as the floor of the trash bin. If the trash bin is not equipped with a floor and is placed on grass, a solid medium must be placed down so as to prevent animals from getting into the trash bin.
The cart of the trash cart system is designed to fit within the trash bin and to store trash cans that are filled throughout the week. On pickup day, the side panel can be unlatched and opened to allow the trash cart to be wheeled out of the trash bin and to the curb. Once the trash has been picked up, the trash cans be placed on the cart again and stored back into the trash bin.
FIG. 2 shows a trash cart ( 100 ) having a side panel ( 105 ), a handle ( 110 ), and a latch/latch spring assembly. The cart is designed to fit into the remaining structure of the trash bin and to latch close once in place using the latch assembly. The latch assembly comprises and latch ( 120 ) attached to a latch spring ( 115 ) which is attached to a handle ( 110 ). Once the handle ( 110 ) is contracted the latch spring ( 115 ) is shifted and the latch ( 120 ) moves in a direction that allows it to disengage from the rest of the trash bin. Being unlatched the trash cart can be rolled away from the rest of the trash bin. When the cart is placed back in the trash bin, the handle ( 100 ) can be contracted and the latch ( 120 ) attached to the rest of the trash bin to lock it in place.
The cart is equipped with a front axle ( 140 ) and a rear axle ( 135 ). The front and rear axles ( 135 , 140 ) have front and rear wheels ( 145 , 155 ) associated attached to the axles. The axles are attached to the underside of the flatbed of the cart ( 130 ). The flat bed of the cart can have a separator ( 125 ) attached to prevent the trash cans from shifting around.
Alternative embodiments of the trash cart are envisioned to be full within the scope of the present invention. For example, FIG. 3 shows one of such alternative embodiments. In this embodiment, the cart fits within the trash bin and does not contain part of the overall trash bin. This embodiment is used in conjunction with a trash bin as shown in FIG. 1 . In other words, this embodiment is directed to a trash bin that has all sides attached, with at least one side attached to the frame by hinges so that it can be opened to remove the cart. In This embodiment, the trash cart ( 200 ) is like a dolly in that it has a flatbed ( 235 ) with a separator panel ( 245 ) and a front lip ( 250 ), a back lip ( 255 ) and side lips ( 215 ) to keep the trash cans from falling off of the cart when being transported to the curb. Once at the curb the dolly can be parked there with the trash cans or the trash cans can be taken off and placed by the curb while the trash cart is placed back into the trash bin.
As with the other carts described above, the trash dolly can have a steering mechanism 205 that is used to maneuver the dolly to the curb. The dolly is equipped with front and rear axles, or in the alternative can have only a single axle towards the rear of the dolly and the front can be lift off of a rest and carried to the curb. The separator can be equipped with handle ( 240 ) that can be used to pull the dolly sideways allowing the dolly to be taken out of the front doors of the bin when opened.
This type of dolly can is used with the trash bin shown in FIG. 4 . The alternative embodiment of the trash cart and bin ( 300 ) comprises many of the same features in the embodiment shown in FIG. 1 except the side panel is not part of the dolly but is attached to the rest of the trash bin via hinges ( 310 ). In this embodiment, the side panel can be opened and the cart pulled down the optional ramp ( 340 ) out of the trash bin.
Still another embodiment of the invention is directed to a trash cart kit comprising a top panel ( 405 ), top panel hinges ( 410 ), separator panel ( 415 ), front panel handle ( 420 ), back panel ( 425 ), right side panel ( 430 ), left side panel ( 435 ), bottom panel ( 440 ), separator panel ( 445 ), wheels ( 450 ), axles ( 455 ), steering means ( 460 ), structural supports ( 465 ), left front door panel ( 470 ) right front door panel ( 485 ), steering connection ( 480 ), instructions to assemble the trash cart ( 485 ), and various fasteners, bolts and pins necessary to connect all of the parts together. The trash cart kit is shown in FIG. 4 and is designed to be easily assembled. The trash cart kit is easier to ship, store, and package, all of which results in savings that can be passed on to the consumer. In addition, compact packaging also allows the consumer to transport the trash cart from the store to home without a truck.
The trash cart, once assembled, has all of the features, attributes and benefits of the fully assembled versions shown in FIGS. 1-3 . The trash cart kit can also includes special fasteners that allow the owner to decorate the trash cart so as to be pleasing to the eye, match the structure in which is stored next to or to just to personalize the cart. For example, the kit can include special fasteners and a printable plate that can be engraved and/or printed with the name and/or address of the owner.
In still another embodiment of the invention, the panels can be almost completely solid having only a few holes for water drainage and/or ventilation. The fasteners can be attached to the top panels ( 405 ), back panel ( 425 ), right side panel ( 430 ), left side panel ( 435 ), bottom panel, left front door panel ( 470 ) and right front door panels allowing for decorative panels to be attached to the trash cart. The decorative panels can be made out of material selected from the group consisting essentially of wood, wrought iron, aluminum, stainless steel, powder coated aluminum, plastic, polyvinyl chloride, powder coated steel, plastic coated metal, man-made materials, new-age materials, or any other material that is washable, strong enough and durable enough for trash cart wear. Custom panels can be made so as to match any structure or to make any trash cart unique.
Another feature that can be added to the trash cart is an internal light that turns on automatically using a light sensor when either the top panel or front doors are opened. This light can be powered by solar or energy from a battery. The same solar charge/battery pack can be used to power an odor control unit that emits a scent to mask the smell of the trash either on a timer or using a malodorous detector that activates the fragrance emitter when odors reach a certain detectable level. The floor of the trash cart may also contain a trash can holding means designed so as to fit the bottom portion of the trash can and prevent it from shifting during transportation to the curb for pick-up. All of these features are known in the art but are unique when incorporated into the present invention.
FIG. 5 gives several examples of decorative panels. These are only examples and many other designs can be used and are anticipated to fall with the scope of the invention. These panels should be weather resistant; however, making the trash cart from a virtually indestructible material will allow the cart to last while changing the decorative panels on the outside would allow the trash cart to look new even though the internal structure is old. This is a direct savings to the consumer and opens up an additional market for decorative panels.
The above embodiments of the present invention can be manufactured using well-established manufacturing techniques used in similar industries today. The technique used to make the present invention is directly related to the material used to make the trash cart. For example, if plastic is used to make the trash cart then the well-established technique of cast molding maybe used. If metals are used to make the trash cart, then welding and/or drop forging of metals maybe used to make the trash cart. And finally, if wood is used to make the present invention then standard wood milling and carpentry techniques can be used. The aforementioned list is not meant to be an exhaustive list designed to cover all of the possible techniques that can be used to make the invention but are only offered as examples. One skilled in the art would manufacture the trash cart using techniques available at the time the trash cart is manufactured.
The materials used to make the present invention should be durable enough to withstand the abuse often associated with trash cans but must be light enough so that the trash cart can be moved easily and without undue effort just to carry the weight of the trash cart.
In another embodiment of the invention, the trash cart is equipped with a motor that is in direct communication with at least one wheel and/or axle of the trash cart that when powered would rotate the wheel and/or axle so as to move the trash cart in the forward or reverse direction. The motor can be powered by gas, electric or some combination of each and can be controlled by either a remote control device or a direct control device.
The trash bin as well as the trash cart can contain at least one wheel so that the trash bin can be moved either with the wheeled trash cart inside the trash bin or not. This will give the option to the user to either move the entire trash bin or to leave the trash bin in place and only move the trash cart. Having wheels on the trash bin also makes it easy to move in order to clean behind and under. This addition can also be incorporated into the kit described herein.
So as not to allow egress of small animals into the main compartment of the trash cart, the panels should have predominately solid construction having only strategic holes for ventilation and water removal. The enclosure should also be designed to keep most of the rain water from getting into the structure. To achieve this task the structure is designed to have a slanted roof so as allow rain to run off of the top panel and avoid pooling of excess water. Although the main compartment of the trash cart is predominately solid construction the homeowner is able to achieve a more airy look using the decorative overlay panels. In other words, the overlay panels, once attached, would allow the home owner to achieve the wrought iron look that by definition has large spaces between each segment—spaces too large to be able to keep animals from getting into the trash cart—while still protecting the trash from animals.
As with most things in life, the trash cart of the present invention would be able to marketed as a standard model containing the basic structure to the deluxe model comprising the basic model plus the add-on features such as decorative overlay panels, outside lighting, odor diffuser, motor with remote control as well as other added features that complement the basic features of the invention. The trash cart can be designed to fit one or more trash cans, preferably two trash cans.
In summary, the present invention is directed to a trash cart that is mobile, easy to get trash cans in and out of, protects the trash cans from animal destruction, is durable, decorative and allows the user to store and transport the trash cans to the curb for collection quickly and without getting soiled.
While the invention has been illustrated and described with respect to specific illustrative embodiments and modes of practice, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited by the illustrative embodiment and modes of practice.
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The present invention is directed to a trash bin, namely an enclosed trash bin having a top and front doors that swing open on a hinged system. The enclosed trash bin contains a detachable cart in which trash and/or trash cans can be placed upon for storage and the cart can be detached from the rest of the trash bin and wheeled to the curb on trash pick-up day. The wheeled cart can either be removed from the inside of the trash bin or makes up at least one portion of the trash bin so that when it is removed it is brought to the curb with at least one portion of the cart. When the cart is returned to the trash bin and placed inside of the bin the trash bin is then whole and impermeable to raccoons and other animals and/or rodents.
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FIELD OF THE INVENTION
The invention relates to a process for the treatment of metal surfaces and more generally the surfaces of ferrous alloy parts.
BACKGROUND OF THE INVENTION
Such treatments are known to a person skilled in the art and are used in the design of mechanical elements, for example when parts have to rub against one another under severe load and pressure conditions. These treatments can be applied both in cases where the ferrous alloy parts are intended to be lubricated (with oil, with grease, and the like) and in cases where the parts are not intended to be lubricated.
Mention may be made, among the various known treatment processes, of processes for surface oxidation in baths of molten salts (mixtures of nitrates and nitrites) which make it possible to improve the corrosion resistance.
Phosphatization processes are also known which make it possible, by the creation of a surface layer of iron phosphate, to substantially improve the effects of the lubrication.
Sulfurization processes, that is to say processes for producing a layer of iron sulfide (FeS) at the surface of ferrous alloy parts with the aim of improving their properties of resistance to jamming, are also known. The parts treated by these sulfurization processes exhibit excellent resistance to rubbing, to wear and to jamming.
The invention relates more particularly to the latter type of treatment.
The sulfurization of steels and its effects on lubrication are known to a person skilled in the art and emerge, for example, from the teaching of patents FR 1 406 530, FR 2 050 754 and FR 2 823 227.
According to the teaching of these patents, the metal parts treated are immersed for 5 to 15 minutes in a bath of ionized molten salts at between 200 and 350° C. preferentially comprising potassium thiocyanate and cyanide ions, the ionization being obtained by an electrolysis, the treated part being positioned at the anode. The layer of FeS is obtained by modifying the surface layer of the ferrous alloy part. This electrolytic sulfurization in molten salts requires specific precautions in order to keep the bath in a stable condition during the passage of the current and necessitates that particular attention be paid to the recycling of the compounds used. Furthermore, this process requires a large amount of salts, which proves to be expensive.
Another solution emerges from the teaching of patent U.S. Pat. No. 6 139 973, which relates to a process which makes it possible to deposit iron sulfide by electrolysis of an aqueous solution comprising ferric ions and thiosulfate or sulfide ions at between 30 and 50° C. The treated part is this time positioned at the cathode. This process results in significant problems of adhesion of the layer of iron sulfide to the treated parts.
A sulfurization treatment by a purely chemical route, without recourse to an electrolysis, is taught in patent FR 2 860 806. The parts are immersed in an aqueous solution comprising sodium hydroxide at a concentration of between 400 and 1000 g/l, sodium thiosulfate and sodium sulfide, at a temperature of greater than 100° C. for approximately 15 minutes. The major disadvantage of this process is the natural carbonatation of the bath, which gradually renders it unusable. This inevitable deterioration imposes both economic and ecological constraints. In addition, the treatment times are lengthy, which is harmful.
SUMMARY OF THE INVENTION
The problem which the invention intends to solve is that of reducing the amount of toxic products generated by the process and of reducing the energy consumption necessitated by the latter, while retaining a high antijamming effect and good adhesion of the layer of iron sulfide to the treated parts.
In order to solve this problem, a process for the surface treatment by electrolysis of ferrous surfaces in order to improve their qualities of rubbing or of resistance to wear and to jamming has been designed and developed, during which process said surfaces form the anode of the electrolysis and the bath of the electrolysis comprises a sulfur-comprising entity, said bath comprises predominantly water and additionally comprises a chlorine-comprising salt and a nitrogen-comprising entity in amounts suitable for making possible or facilitating the sulfurization reaction of said surfaces.
The antijamming effect obtained is good and is highly reproducible. The layer of iron sulfide obtained adheres well to the surface. The amount of salts and other starting materials used is low. The production of toxic waste is limited and the consumption of energy required by the reaction is low. The process is thus an excellent compromise, combining effectiveness and savings.
DETAILED DESCRIPTION OF THE INVENTION
The bath can be an aqueous solution.
Preferably, the sulfur-comprising entity is a sulfide. It can be sodium monosulfide, potassium monosulfide or ammonium monosulfide. It can also be a thiosulfate, such as sodium thiosulfate, potassium thiosulfate or ammonium thiosulfate. It can also be a sulfite.
Preferably, the sulfide is introduced at a concentration equivalent to a concentration of sulfide ions of between 20 g/l and 90 g/l.
Preferably, the sulfide is sodium monosulfide, introduced at a concentration between 50 and 200 g/l.
Preferably, the chlorine-comprising salt is a chloride, for example sodium, potassium, lithium, ammonium, calcium or magnesium chloride. It can also be a hypochlorite, a chlorite, a chlorate or a perchlorate, equally, for example, of sodium, potassium, lithium, ammonium, calcium or magnesium.
Preferably, the chloride is introduced at a concentration equivalent to a concentration of chloride ions of between 15 and 200 g/l approximately.
Preferably, the chloride is sodium chloride, introduced at a concentration between 30 and 300 g/l.
Preferably, the content of nitrogen-comprising entity is between 100 ml/l and 300 ml/l approximately. The nitrogen-comprising entity can comprise one nitrogen or several nitrogens. It can, for example, be a base, optionally a weak base, indeed even a very weak base. It can also be a base which has been weakened, for example by a substituent, or, conversely, a base which has been strengthened. It can be an organic entity.
Preferably, the nitrogen-comprising entity is an amine, for example a monosubstituted or polysubstituted amine. It is, for example, triethanolamine, methylamine, phenylamine, diethylamine, diphenylamine or cyclohexylamine, for example. The amine can be introduced in the form of an amino acid, such as alanine, glutamic acid or proline, for example. The nitrogen-comprising entity can also be an amide, an amidine, a guanidine, a hydrazine or a hydrazone. It can also be a mixture of these compounds. The nitrogen-comprising entity can also carry one or more oxygen atoms or one or more alcohol functional groups at a chosen distance from the nitrogen or at chosen distances from the nitrogen atom or nitrogen atoms. It can also carry other atoms or other functional groups.
Preferably, triethanolamine is used and the amount of triethanolamine introduced is between 100 ml/l and 300 ml/l approximately. The mechanism of action of this molecule has not been clarified and the respective roles of each of the characteristics of this molecule are not known.
If appropriate, the content of nitrogen-comprising entity is evaluated as triethanolamine equivalent according to conventional methods, in which case the preferred content of nitrogen-comprising entity is equivalent to a content of triethanolamine of between 100 ml/l and 300 ml/l.
Preferably, the operating temperature of the bath is less than 70° C. It can be ambient temperature, which reduces the energy consumption.
Preferably, the duration of the treatment by electrolysis is less than 1 hour or, in some cases, less than 10 minutes, indeed even less than one minute.
Preferably, the electrolysis is carried out using a continuous current.
According to one characteristic, the electrolysis is carried out using a pulsating current. The latter can be applied in the form of a slot-like signal or in another form.
Preferably, the pulsating current has a frequency of less than 500 kHz (that is to say, a period of greater than 2 μs).
The duration of the pulses is less than the period of the signal and, according to one characteristic, it is less than 50 ms.
Preferably, the mean current density is between 3 and 15 A/dm 2 and is, for example, 8 A/dm 2 approximately or 5 A/dm 2 .
Preferably, the cathode is made of a conducting material which is inert in the solution. Preferably, it is made of stainless steel.
Finally, the invention also relates to the parts, the surface of which is treated according to the process according to the invention.
According to a preferred embodiment, the parts to be treated are positioned in an electrolysis bath at the anode. A current density is applied between the parts and a cathode. The duration of the treatment is between a few seconds and 10 minutes, indeed even 20 minutes, 30 minutes or more, according to the geometry and the surface area of the parts to be treated. The treatment is typically carried out at a temperature of less than 70° C.
The resistance to jamming resulting from the treatment process according to the invention is evaluated according to the test on the Faville Levally machine according to standard ASTM-D-2170.
In a way known to a person skilled in the art, this test consists in treating a case-hardened, quenched and ground 16NC6 steel cylindrical test specimen with a diameter of 6.35 mm and a height of 50 mm. The test specimen is clamped between two jaws cut in a right-angled V to which a load is applied which increases linearly as a function of time. The test is halted when jamming or creep of the test specimen occurs. This test is characterized by a quantity referred to as the Faville grade, which is the integral of the load applied with respect to time, this grade being expressed in daN.s.
Reference is made below to the examples, which are given by way of indication without any limitation and which show the results obtained with the characteristics of the process according to the invention, in comparison with treatments according to the prior state of the art.
It is apparent that, when the test specimen is treated according to the process in accordance with the invention, the test specimen creeps and does not jam and that its Faville grade is generally greater than 12 000 daN.s.
EXAMPLE 1
According to this example, the Faville grade of case-hardened quenched 16NC6 steel test specimens is compared in the case of an untreated test specimen (1), of a phosphatized test specimen (2) and of a test specimen in accordance with the process of the invention (3).
The test specimen according to the invention is quenched in an aqueous solution and maintained at the anode. The cathode is made of stainless steel. At the preparation of the bath, the aqueous solution comprises 100 g/l of sodium monosulfide, 50 g/l of sodium chloride and 200 ml/l of triethanolamine.
According to a first alternative form, the treatment is carried out at ambient temperature (20° C.) for 10 seconds, the current is continuous and the current density applied is 8 A/dm 2 .
According to a second alternative form, the treatment is carried out still at ambient temperature but for 5 minutes, with a pulsating current at a frequency of 25 Hz (that is to say, with a period of 40 ms), the duration of the pulses being 10 ms and the period-averaged current density being 4 A/dm 2 .
Reference is made to the table below:
3
4
2
Test specimen
Test specimen
Phosphatized
sulfurized
sulfurized
1
test specimen
according to
according to
Untreated
(iron/
the invention
the invention
test
manganese
(1st alternative
(2nd alternative
specimen
phosphatization)
form)
form)
Faville
5000
5500
15 000
15 000
grade
(daN ·
s)
Halting
Jamming
Jamming
Creep
Creep
of the
test
It emerges from this test that the test specimens 1 and 2 have no antijamming property whereas the test specimens 3 and 4, in accordance with the invention, have good antijamming properties.
EXAMPLE 2
In this example, a comparison is made between the Faville grades of case-hardened quenched 16NC6 steel test specimens sulfurized by the process in accordance with the invention (1) and by the electrolytic process in a medium formed of baths of molten salts, as emerges from the teaching of patent FR 2 050 754. Reference is made to the table below:
1
2
3
Test specimen
Test specimen
Test specimen
sulfurized
sulfurized
sulfurized in
according to the
according to the
accordance
invention (1st
invention (2nd
with
alternative form)
alternative form)
FR 2 050 754
Faville grade
15 000
15 000
15 000
(daN · s)
Halting of
Creep
Creep
Creep
the test
The test specimen according to the invention is immersed in a bath of an aqueous solution and maintained at the anode. The cathode is made of stainless steel. At the preparation of the bath, the aqueous solution comprises 100 g/l of sodium monosulfide, 50 g/l of sodium chloride and 200 ml/l of triethanolamine.
According to a first alternative form, the treatment is carried out at ambient temperature (20° C.) for 10 minutes with a pulsating current at a frequency of 200 kHz (that is to say, with a period of 5 μs), the duration of the pulses being 2 μs and the period-averaged current density being 4 A/dm 2 .
According to a second alternative form, the treatment is carried out still at ambient temperature but for 10 minutes, with a continuous current and a current density of 5 A/dm 2 .
It emerges from these tests that the solutions 1, 2 and 3 have entirely similar antijamming properties.
A person skilled in the art will adjust the duration of the treatment, which can be between a few seconds and 30 minutes, indeed even more, being, for example, of an order of magnitude of 10 minutes, according to the geometry and the surface area of the parts to be treated. He will also adjust the temperature, which can be ambient temperature or a temperature of less than 70° C. or more. He will also adjust the current density.
The advantages clearly emerge from the description; in particular, the following are emphasized and restated:
respect for the environment, control, with great accuracy and high reproducibility, of the composition, of the adhesion and of the continuity of the surface layers, treatment at ambient temperature, making it possible to reduce the energy consumption, short or very short treatment time, making it possible to produce shorter operating cycles.
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The invention relates to a superficial treatment method by electrolysis of ferrous surfaces to enhance friction or tread and seizing resistance features, wherein the surfaces provide the electrolysis anode, the electrolysis bath includes a sulphur species, primarily contains water and also contains a chloride salt and a nitrogen species in quantities which facilitates the sulphuration reaction of the surfaces.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a lubricating oil composition having a low coefficient of friction and a reduced copper corrosiveness.
2. Description of the Related Art
In recent years, an increase in the output of internal combustion engines such as automobile engines has caused individual parts of the engine, for example valve operating systems and cylinders, to be exposed to high temperatures. Moreover, the number of contacts per unit time of metals with each other has been increased, thus placing the internal combustion engine under severe operating conditions. Lubricating oils for internal combustion engines must function under severe operating conditions. With a reduction in engine size and an increase in the performance which results in an increase in the number of revolutions and an increase in the output, engine oils are required to be versatile and possess high levels of performance.
Examples of fundamental performances required of the engine oils include detergency, dispersancy, a reduction in the friction, prevention of abrasion and seizing, reduction of thermal and oxidative deterioration, reduction of corrosion, and cooling and sealing functions. For example Japanese Patent Publication No. 23595/1991 proposes a lubricating oil composition particularly useful in the reduction in the mechanical friction loss of four-cycle engines, said lubricating oil composition comprising a mineral oil and/or a synthetic oil having a kinematic viscosity at 100 degrees C. of 3 to 20 cSt and, incorporated therein, (a) 0.2 to 5% by weight of sulfurized oxymolybdenum organophosphorodithioate (hereinafter abbreviated to "MoDTP" and/or molybdenum dithiocarbamate (hereinafter abbreviated to as "MoDTC"), (b) 0.1 to 7% by weight of zinc dithiophosphate, (c) 0.1 to 20% by weight of calcium alkylbenzenesulfonate and (d) 1 to 15% by weight of an alkenylsuccinimide and/or a boron compound derivative of an alkenylsuccinimide. According to this lubricating oil composition, the coefficient of friction in the mixed/boundary region can be reduced to about 1/3 of that for the conventional engine oil.
One of the important features of the lubricating oil is that the lubricating oil does not attack a metal present within the engine during use. Free sulfur, sulfur compounds, or acidic substances are considered to cause corrosion. Since a copper plate is most sensitive to these substances, the corrosion of a copper plate when exposed to lubricating oil is evaluated as a measure of the corrosiveness of the lubricating oil. It is a common practice to add nitrogenous metal deactivators, such as benzotriazole, to the lubricating oil for the purpose of reducing the copper corrosiveness. However, the addition of these metal deactivators in a large amount results in hardening of sealing rubbers.
On the other hand, when MoDTP or MoDTC is added in a relatively large amounts of 0.2 to 5% by weight as disclosed in the above-cited Japanese Patent publication for the purpose of reducing the friction, the copper corroding activity is unacceptably increased.
Further, lubricating oils containing organomolybdenum compounds, such as MoDTP or MoDTC, have a problem of a high coefficient of friction at an early stage, i.e., at the stage of running-in. The additive to the lubricating oil is adsorbed on the surface of the metal to form a boundary lubrication film which serves to reduce boundary friction. However, a relatively substantial amount of time is taken for the organomolybdenum compounds to be adsorbed on the surface of the metal to develop the effect of reducing the friction.
When lubricating oil compositions containing the organomolybdenum compounds are used as an engine oil, the effect of reducing the friction develops after running a distance of 2000 to 3000 km, although this depends upon the running conditions of automobiles. However, after the above-described running, the time for the development of the effect of reducing the friction often overlaps with the time for the replacement of the engine oil. In such a case, an increase in the amount of addition of MoDTP or MoDTC does not lead to the development of the effect of reducing the friction at an earlier stage and rather increases the copper corrosiveness.
It would be desirable to provide a lubricating oil composition having a low coefficient of friction and a reduced copper corrosiveness. It would also be desirable to provide a lubricating oil composition which exhibits a low coefficient of friction from an early stage and has reduced copper corrosiveness.
SUMMARY OF THE INVENTION
The present invention relates to improved lubricating oil compositions having a low coefficient of friction, reduced copper corrosivity and which exhibit a low coefficient of friction from an early operating stage. The lubricating oil composition comprises:
(a) a lubricating oil basestock;
(b) from 0.01 to 10% by weight, based on the oil composition, of at lease one organomolybdenum compound selected from the group consisting of oxymolybdenum monoglyceride and oxymolybdenum diethylateamide; and
(c) from 0.5 to 7% by weight, based on the oil composition, of at least one organozinc compound selected from the group consisting of zinc dithiophosphate and zinc dithiocarbamate.
In another embodiment, the lubricating oil composition further comprises from 0.01 to 5% by weight, based on the composition, of an organic acid amide. The present invention is also directed to a method for reducing friction in an internal combustion engine which comprises operating the engine with the lubricating oil composition containing components (a)-(c) above.
DETAILED DESCRIPTION OF THE INVENTION
The mineral oil and/or synthetic oil used as a base oil in the lubricating oil composition of the present invention has a kinematic viscosity of 3 to 20 cSt at 100° C., preferably 4 to 15 cSt. Examples of the mineral oil include 60 neutral oil, 100 neutral oil, 150 neutral oil, 300 neutral oil, 500 neutral oil and a bright stock. Examples of the synthetic oils include polyolefin, polyglycol ester, polyol ester, phosphoric ester, silicone oil, alkyldiphenyl, alkylbenzene and dibasic acid ester. These base oils may be used alone or in the form of a mixture of two or more of them.
The Mo oxide compounds used in the present invention are oxymolybdenum monoglyceride represented by the following general formula I and oxymolybdenum diethylatoamide represented by the following general formula II: ##STR1##
In the general formulae I and II, R is a hydrogen atom; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 6 to 26 carbon atoms; an aryl, alkylaryl or arylalkyl group having 6 to 26 carbon atoms; or a hydrocarbon group having from 3 to 20 carbon atoms and containing an ester bond, an ether bond, an alcoholic group or a carboxyl group.
In the general formulae I and II, R is preferably a saturated or unsaturated alkyl or alkenyl group having 6 to 18 carbon atoms, a cycloalkyl group having 12 to 24 carbon atoms or an alkylaryl group having 12 to 24 carbon atoms. Preferred examples thereof include alkyl and alkenyl groups having 6 to 18 carbon atoms, such as n-hexyl, 2-ethyl hexyl , n-octyl, nonyl, decyl, lauryl, tridecyl, oleyl and linoleyl, and alkylaryl groups substituted with an alkyl group having 3 to 18 carbon atoms, such as nonylphenyl.
The amount of the commercially available Mo oxide compounds is 0.01 to 10% by weight, preferably 0.05 to 8% by weight, based on the oil composition independently of whether they are used alone or in combination thereof. When the amount is less than 0.01% by weight, no satisfactory effect of reducing the friction can be attained. On the other hand, when the amount is excessively high, the effect of reducing the friction is saturated.
ZnDTP and ZnDTC used in the present invention are organozinc compounds respectively represented by the following general formulae III and IV: ##STR2##
In the general formulae III and IV, R 1 and R 2 may be the same or different and each is independently a hydrogen atom; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 6 to 26 carbon atoms; an aryl, alkylaryl or arylalkyl group having 6 to 26 carbon atoms; or a hydrocarbon group having from 3 to 20 carbon atoms and containing an ester bond, an ether bond, an alcohol group or a carboxyl group.
In the general formulae III and IV, R 1 and R 2 are preferably independently an alkyl group having 2 to 12 carbon atoms, a cycloalkyl group having 8 to 18 carbon atoms and an alkylaryl group having 8 to 18 carbon atoms.
ZnDTP and ZnDTC are commercially available from Amoco Chemical Co. and Exxon Chemical Co. and are incorporated either alone or in combination in an amount of 0.5 to 7% by weight based on the oil composition. These compounds serve as an extreme-pressure agent, an antioxidant, a corrosion inhibitor, etc. When the amount of these compounds incorporated into the oil composition is excessively low, no satisfactory effect of addition can be attained. On the other hand, when it is excessively high, the effect of addition is often saturated or even lowered.
The organic amide used in the present invention is a compound represented by the following general formula V: ##STR3##
In the general formula V, R 4 and R 5 may be the same or different and for each is independently a hydrogen atom; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 6 to 26 carbon atoms; an aryl, alkylaryl or arylalkyl group having 6 to 26 carbon atoms; or an alkylene oxide group having 2 to 30 carbon atoms, and R 3 stands for a hydrogen atom; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 6 to 26 carbon atoms; an aryl, alkylaryl or arylalkyl group having 6 to 26 carbon atoms; or a hydrocarbon group having from 3 to 20 carbon atoms and containing an ester bond, an ether bond, an alcohol group or a carboxyl group.
The term "alkylene oxide group" used herein is intended to mean groups represented by the following general formula VI and/or VII: ##STR4##
In the general formulae VI and VII, n is an integer of 1 to 10, and R 6 stands for a hydrogen atom or a methyl group.
In the general formula V, R 4 and R 5 are preferably independently a hydrogen atom, an alkyl group having 2 to 8 carbon atoms, a cycloalkyl group having 8 to 14 carbon atoms, an alkylaryl group having 8 to 14 carbon atoms or an alkylene oxide group wherein n is 1 to 5. In the general formula V, R 3 preferably stands for a saturated or unsaturated alkyl group having 6 to 18 carbon atoms, a cycloalkyl group having 12 to 24 carbon atoms or an alkylaryl group having 12 to 24 carbon atoms. Examples of such an organic amide compound include oleamide and lauramide.
The amount of the organic amide compound is 0.01 to 5% by weight, preferably 0.05 to 2% by weight based on the oil corporation. The addition of the organic amide compound enables the coefficient of friction to be lowered from an early stage while preventing copper corrosion. If the amount is excessively low, the effect of lowering the coefficient of friction in an early stage is small. On the other hand, if the amount is excessively high, the effect is saturated.
If desired, other additives, for example, other extreme-pressure agents, ashless detergent dispersants, antioxidants, metal cleaners, metal deactivators, viscosity index improvers, pour point depressants, rust preventives, antifoaming agents, and corrosion preventives, may be added to the lubricating oil composition.
Examples of other extreme-pressure agent include organomolybdenum compounds such as sulfurized oxymolybdenum dithiocarbamate (MoDTC) and sulfurized oxymolybdenum organophosphorodithioate (MoDTP). These organomolybdenum compounds are generally used in an amount from 0.01 to less than 0.2% by weight, based on oil composition. When the proportion of MoDTC and MoDTP is above the above-described range, the copper corrosiveness becomes significant.
Examples of the ashless detergent dispersant include those based on succinimide, succinamide, benzylamine and esters, and it is also possible to use boron-base ashless detergent dispersants. They are generally used in an amount of from 0.5 to 7% by weight, based on oil composition.
Examples of the antioxidant include amine-based antioxidants, such as alkylated diphenylamine, phenyl-a-naphthylamine and alkylated a-naphthylamine, and phenolic antioxidants, such as 2,6-di-tert-butylphenol and 4,4'-methylenebis-(2,6-di-tert-butylphenol), and they are generally used in an amount of from 0.05 to 2% by weight based on oil composition.
Examples of the metal cleaner include Ca sulfonate, Mg sulfonate, Ba sulfonate, Ca phenate and Ba phenate, which are generally used in an amount of from 0.1 to 5% by weight, based on oil composition.
Examples of the metal deactivator include benzotriazole, benzotriazole derivatives, benzothiazole, benzothiazole derivatives, triazole, triazole derivatives, dithiocarbamate, dithiocarbamate derivatives, indazole and indazole derivatives, which are generally used in an amount from 0.0005 to 0.3% by weight based on oil composition.
Examples of the viscosity index improver include polymethyl methacrylate, polyisobutylene, ethylene-propylene copolymer and styrene-butadiene hydrogenated copolymer, which are generally used in an amount of from 0.5 to 35% by weight, based on oil composition.
Examples of the rust preventive include an alkenylsuccinic acid and a partial ester thereof, which is added as needed.
Examples of the anti foaming agent include dimethylpolysiloxane and polyacrylate, which is added as needed.
The lubricating oil composition of the present invention can be produced by incorporating the desired amount of the above-described various additives to a mineral oil and/or a synthetic oil as a base oil and homogeneously mixing them with each other. The lubricating oil composition of the present invention can be used in extensive fields as lubricating oils including engine oils and, further, gear oils, ATF, PS fluids, spindle oils, hydraulic oils, industrial oils, etc.
The present invention is further illustrated with reference to the following Examples which include a preferred embodiment of the invention.
The properties of the lubricating oils were measured by the following methods.
Measurement of Coefficient of Friction
The coefficient of friction of each lubricating oil was measured with a reciprocal vibration friction tester (SRV).
In the SRV tester, a steel ball having a diameter of 1/2 in. (SUJ-2 specified in JIS G 4805) was used as the upper test piece, and a steel disk (SUJ-2 specified in JIS G 4805) was used as the lower test piece. A sample oil was dropped on the lower test piece, a load was applied to the upper test piece from the top, and the upper test piece was vibrated parallel to the lower test piece with the upper test piece being pressed against the lower test piece. The lateral load applied to the lower test piece was measured to calculate the coefficient of friction (μ). The coefficient of friction was measured twice, that is, 5 min and 20 min after the initiation of the vibration of the upper test piece. Testing conditions were as follows:
load: 100N,
temperature: 130° C.,
frequency: 8 Hz, and
amplitude: 4 mm.
Copper Corrosiveness
A corrosiveness test was conducted at a testing temperature of 100° C. and a testing time of 3 h by the test tube method according to JIS K 2513 "Petroleum Products--Corrosiveness to Copper--Copper Strip Test" and the state of discoloration of the copper plate was observed according to the Standard for Copper Plate Corrosion to evaluate and the corrosiveness according to subdivisional symbols 1a to 4c. The smaller the number, the lower the corrosiveness, and the corrosiveness increases in alphabetical order.
Specific evaluation examples are as follows:
1a: a pale orange color which is substantially the same as the color of a finish-polished copper plate,
1b: a deep orange color, and
3a: a reddish brown pattern on the brass color.
EXAMPLES 1 TO 6 AND COMPARATIVE EXAMPLES 1 AND 2
4% by weight of Ca sulfonate, 5% by weight of succinimide, 0.5% by weight of an alkylated diphenylamine, 0.3% by weight of 2,6-di-tert-butylphenol and 0.2% by weight of 5-methyl-benzotriazole were incorporated into a mineral oil (150 neutral mineral oil; kinematic viscosity at 100 X C of 5.1 cSt), and the various components listed in Table 1 were added thereto to prepare lubricating oil compositions. The amount in % by weight of each component is based on the oil composition, and the balance is the amount in % by weight of the mineral oil. The results of measurement of the properties are given in Table 1.
Individual components are described as follows:
(1) Mo oxide Compound ##STR5## (2) MoDTC (Sakura-Lube® manufactured by Asahi Denka Kogyo K.K.) ##STR6## wherein 2EH stands for a 2-ethylhexyl group, (3) MoDTP (Molyvan L® manufactured by R. T. Vanderbilt) ##STR7## wherein 2EH stands for a 2-ethylhexyl group, (4) ZnDTP (Paranox 16® manufactured by Exxon Chemical Co.) ##STR8## wherein 2EH stands for a 2-ethylhexyl group, (5) ZnDTC ##STR9## wherein 2EH stands for a 2-ethylhexyl group, (6) Ca sulfonate (Hitec 611® manufactured by Ethyl Corp.) ##STR10## wherein R stands for an alkyl group having 10 carbon atoms, and (7) succinimide ##STR11## wherein PiB stands for polyisobutylene.
TABLE 1______________________________________ Compar- ative Examples Examples 1 2 3 4 5 6 1 2______________________________________Mo Oxide 0.7* 3.0 2.0 3.0 0.7 1.0 -- 1.0CompoundMoDTC -- -- 0.07 -- -- -- 0.30 --MoDTP -- -- -- 0.10 -- -- -- --ZnDTP 2.0 3.0 2.0 2.0 2.0 2.0 2.0 --ZnDTC -- 1.0 -- 0.5 -- -- -- --Oleic amide -- -- -- -- 0.5 -- -- --Lauramide -- -- -- -- -- 0.5 -- --FrictionCoefficient ()After 5 min. 0.13 0.13 0.13 0.11 0.05 0.06 0.13 0.14After 20 min. 0.06 0.05 0.05 0.05 0.04 0.05 0.11 0.65Copper Ia Ia Ia Ib Ia Ia 3a IaCorrosion______________________________________ *percent by weight based on the oil compositon
As is apparent from Table 1, each of the lubricating oil compositions of Examples 1 to 4 of the present invention had a small coefficient of friction 20 min after the initiation of the test and, at the same time, a small copper corrosiveness. By contrast, the lubricating oil composition of Comparative Example 1 wherein MoDTC was incorporated in an amount of 0.30% by weight had a large coefficient of friction 20 min after the initiation of the test and, at the same time, a large copper corrosiveness. Further, the lubricating oil composition of Comparative Example 2 wherein neither ZnDTP nor ZnDTC was used in combination with Mo oxide compounds had a tendency that the coefficient of friction increases with time.
Further, it is apparent that each of the lubricating oil compositions of Examples 5 and 6 wherein an organic amide compound was also used had a small coefficient of friction 5 min after the initiation of the test, which suggests that these lubricating oil compositions exhibit the effect of reducing the friction from the beginning.
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An improved lubricating oil composition having a low coefficient of friction and reduced copper corrosion comprising (a) a lubricating oil basestock, (b) from 0.01 to 10% by weight, based on the oil composition, of at least one organomolybdenum compound selected from the group consisting of oxymolybdenum monoglyceride and oxymolybdenum diethylatoamide; and (c) from 0.5 to 7% by weight, based on the oil composition, of at least one organozinc compound selected from the group consisting of zinc dithiophosphate and zinc dithiocarbamate.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/227,415, filed Sep. 7, 2011, now U.S. Pat. No. 8,605,216, which is a continuation of U.S. application Ser. No. 13/041,305, filed Mar. 4, 2011, now U.S. Pat. No. 8,035,742, which is a continuation of U.S. application Ser. No. 12/731,082, filed Mar. 24, 2010, now U.S. Pat. No. 7,936,399, which is a continuation of U.S. application Ser. No. 12/428,344, filed Apr. 22, 2009, now U.S. Pat. No. 7,714,933, which is a continuation of U.S. application Ser. No. 12/060,779, filed Apr. 1, 2008, now U.S. Pat. No. 7,542,096, which is a continuation of U.S. application Ser. No. 10/944,389, filed on Sep. 17, 2004, now U.S. Pat. No. 7,430,016, which claims the benefit of and priority to the Korean Application No. 10-2003-064442 filed on Sep. 17, 2003, the contents of all of which are hereby incorporated by reference herein in their entireties.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital cable broadcast receiver, and more particularly, to a digital cable broadcast receiver and a method for processing a caption thereof that can process a caption of a various types and standards for use in a digital cable broadcast, in an adaptive manner.
2. Discussion of the Related Art
A ground wave broadcast standard for an analog broadcast in USA (United States of America) is an NTSC (national television system committee) standard. The NTSC standard is characterized in transmitting a closed caption such as English, Spanish, using a 21 st line of a VBI (vertical blanking interval) of a broadcast signal. A standard related to the transmission of the closed caption is an EIA (electronic industry association) standard 608. Services provided through a 21 st line of the VBI under the EIA 608 standard are as follows: CC1 (primary synchronous caption service), CC2 (special asynchronous caption service), CC3 (secondary synchronous caption service), CC4 (special asynchronous caption service), Text1 (first letter information service), Text2 (second letter information service), Text3 (third letter information service), Text4 (fourth letter information service).
In USA, a user has to select, in person, one among the above-mentioned services. Further, since there is no information as to which service is provided among the above-mentioned eight services while a broadcast program is displayed, there has been a difficulty that a user should check, case by case, the services so as to check a service under execution.
A ground wave broadcast standard for a digital broadcast in USA is an ATSC (advanced television system committee) standard. Further, an EIA 708, which is a standard on a digital TV closed caption (DTVCC), is established. The DTVCC will be described with reference to the accompanying drawings. FIG. 1 illustrates the general bit stream provided to a digital TV. As shown in FIG. 1 , the bit stream includes: audio data, video data, control data (i.e., supplementary information). Data that corresponds to the DTVCC is included in user_data bits of the video data and transmitted under an MPEG-2 (Moving Picture Experts Group-2) video standard and the ATSC standard (A53). At this point, according to the above standards, the DTVCC data can be transmitted up to as much as 128 bytes at its maximum for each user_data region and the total transmission amount cannot exceed 9600 bps (bit per second). Compared with an analog closed caption based on the EIA 608, where the total transmission amount cannot exceed 960 bps, the DTVCC based on the EIA 708 has realized ten times greater bandwidth in its data transmission. The DTVCC based on the EIA 708 can provide sixty-three caption services in total with consideration of the extended bandwidth. In case of the sixty-three digital caption services, there is a difficulty that a user should change settings to find out a desired caption service as was done in the above-described analog closed caption. Due to such reason, in case of providing a DTVCC according to the ATSC standard, a broadcast station must include information called a caption_service_descriptor within an EIT (event information table) or a PMT (program map table) in a PSIP (program and system information protocol). The EIT and the caption_service_descriptor allow a DTV receiver to know what kind of the DTVCC is included in a relevant program.
The cable broadcast is a little different from the ground wave broadcast depending on regions, or service companies, or broadcast equipments. In particular, the cable broadcast is the same as the ground wave analog broadcast in that transmission is performed on the basis of a letter value and a command set prescribed by the EIA 608 in operating a closed caption. However, the cable broadcast is different from the ground wave broadcast in transmitting the closed caption using other interval of the VBI except a 21 st line of the VBI. That is, some broadcast station transmits a caption using a sixth line of the VBI while other broadcast station transmits a caption using a tenth line. In the meantime, as an analog cable broadcast is switched into a digital cable broadcast, a closed caption standard regarding the digital broadcast has been established independently. The basic object of standards tilted SCTE (society of cable television engineers) 20 and DVS (digital video surveillance) 157 is to convert an analog closed caption for use in the analog cable broadcast into user_data within a video data region for use in a digital TV. Those standards do not include content regarding a DTVCC of the EIA 708 standard but only prescribe content regarding the analog closed caption as is done in the existing standards.
The ATSC standard regarding the DTVCC does not consider the closed caption under the SCTE 20 or the DVS 157 which are caption transmission standards for use in the cable broadcast. Since a cable broadcast service company has provided a cable set top box appropriate for the company's broadcast to each user, there was little problem in a digital-cable-broadcast generation before an open-cable generation. However, under a new digital broadcast environment such as an open cable and a Cable Ready, there occur problems regarding the standards. That is, under the open cable and the Cable Ready environments whose object is to connect an apparatus generally available in the market, not a specific cable broadcast receiver provided by a specific cable broadcast company, to a cable, a method for transmitting/receiving a caption emerges as a very complicated problem.
An open cable broadcast signal under regulations of a FCC (federal communications commission) must include a DTVCC and an analog CC (closed caption) prescribed by the EIA 708. Further, the open cable broadcast signal should include user_data of other type prescribed by the SCTE 20 or the DVS 157 and may include a relevant caption at a S-Video, a Composite, a 480i, and a VBI line of the Component output. Therefore, the cable broadcast receiver should know what kind of caption data is included in a digital cable broadcast being received. However, it is difficult for the cable broadcast receiver to judge a kind of caption data being received in view of characteristics of caption data. Accordingly, a user should check in person the caption data through a key or a menu on a remote control. Also, a user should experimentally select and check what kind of caption data is decoded.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a digital cable broadcast receiver and a method for processing a caption thereof that substantially obviate one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a digital cable broadcast receiver and a method for processing a caption thereof that can automatically process caption data of various standards and types.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a digital cable broadcast receiver including: a demultiplexer for dividing a received broadcast stream into video data, audio data, supplementary information; a controller for judging whether caption data included in the video data is digital caption data or analog caption data on the basis of caption information included in the supplementary information, and outputting a control signal according to a result of the judgment; a digital caption decoder for extracting and decoding digital caption data from the video data according to the control signal; and an analog caption decoder for extracting and decoding analog caption data from the video data according to the control signal.
The controller judges a number of caption services, a national language, a difficulty level of a caption, a line number and a field of a VBI that corresponds to the caption data, a picture ratio, provided by the caption data included in the video data, on the basis of the caption information.
If the caption data included in the video data is digital caption data, the controller detects a caption service number that corresponds to the caption data from the caption information and transmits the control signal including the detected caption service number to the digital caption decoder.
If the caption data included in the video data is analog caption data, the controller judges the caption data's standard on the basis of the caption information. If the caption data is an analog caption data of an EIA 708, the controller detects field information that corresponds to the caption data from the caption information, and transmits the control signal including the detected field information to the analog caption decoder, and if the caption data is an analog caption data of the SCTE 20 or the DVS 157 standards, the controller detects field information and VBI line information that correspond to the caption data and transmits the control signal including the detected field information and the VBI line information, to the analog caption decoder.
In another aspect of the present invention, a digital broadcast receiver further includes: a program map table (PMT) buffer for storing a PMT included in the supplementary information and transmitting the stored PMT to the controller; an event information table (EIT) buffer for storing an EIT included in the supplementary information and transmitting the stored LIT to the controller; and a graphic block for receiving characteristic information of the caption data detected from the supplementary information, from the controller and displaying characteristics of the caption data on a screen.
In still another aspect of the present invention, a method for processing caption includes the steps of: dividing a received broadcast stream into video data, audio data, and supplementary information; judging whether caption data included in the video data is digital caption data or analog caption data on the basis of caption information included in the supplementary information; and selectively detecting at least one of parameters included in the caption information according to a result of the judgment; and extracting and decoding the caption data included in the video data on the basis of the detected parameter.
The step of selectively detecting at least one of parameters included in the caption information according to the result of the judgment, includes the step of: if the caption data included in the video data is digital caption data, detecting a caption service number that corresponds to the caption data from the caption information.
The step of selectively detecting at least one of parameters included in the caption information according to the result of the judgment, includes the step of: if the caption data included in the video data is analog caption data, detecting a standard of the caption data on the basis of the caption information; and detecting at least one of parameters included in the caption information according to the detected standard. At this point, if the detected standard of the caption data is the EIA 708, a field value that corresponds to the caption data is detected from the caption information and if the detected standard of the caption data is the SCTE 20 or the DVS 157, a field value and a VBI line number that correspond to the caption data are detected from the caption information.
The method for processing caption further includes the steps of: detecting characteristics of the caption data included in the video data on the basis of the caption information; and displaying the detected characteristics on a screen.
The characteristics of the caption data includes at least one among a number of caption services, a national language of a caption, a difficulty level of a caption, a picture ratio of a caption, a field value and a VBI line number that correspond to the caption data, provided by the caption data.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
FIG. 1 is a view illustrating a bit stream of the general digital broadcast;
FIG. 2 is a view illustrating a syntax of caption information according to the present invention;
FIG. 3 is a block diagram illustrating a construction of a broadcast receiver according to the present invention; and
FIG. 4 is a flowchart illustrating a method for processing a caption according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
A digital cable broadcast under an open cable and a Cable Ready standards observes an ATSC standard. Therefore, the caption_service_descriptor the EIT or the PMT within the PSIP, included in the digital cable broadcast signal is prescribed by the ATSC standard (A65, Program and System Information Protocol for Terrestrial Broadcast and Cable).
FIG. 2 is a view showing a syntax of the caption_service_descriptor under the open cable and the Cable Ready standards according to the present invention. “descriptor_tag”, which is a parameter for checking a type of a descriptor, is described by 8 bits. “descriptor_length”, which is a parameter representing a length of the whole structure, is described by 8 bits. “number_of_services” represents a number of provided caption services and is described by 5 bits. “language” represents language information of a relevant caption, such as English for a service 1 and Spanish for a service 2, and is a 3-byte language code under ISO 639.28, each letter of which is coded with 8 bits and inserted into a 24-bit field. “cc_type” represents a kind of caption. If cc_type==1, it is a digital caption (advanced caption) and if cc_type==0, it is an analog caption (analog caption under the EIA 708 or the SCTE 20 (DVS 157)). The “cc_type” is described by 1 bit. “analog_cc_type” represents a kind of an analog caption. If analog_cc_type==1, it means caption data transmitted through a line 21 of the VBI under the EIA 708, and if analog_cc_type==0, it means caption data transmitted through other line except the line 21 of the VBI according to the SCTE 20 or the DVS 157. “line_offset” represents a number of the VBI line including the caption data in case caption data under the SCTE 20 or the DVS 157 is transmitted, namely, in case the analog_cc_type==0, and is described by 5 bits. “line_field” represents whether the caption data is included in an even field or an odd field. That is, if line_field==0, it means the caption data is included in an odd field and if line_field==1, it means the caption data is included in an even field. “caption_service_number” represents 1-63 caption service numbers in case it is a digital caption, namely, in case cc_type==1. and is described by 6 bits. “easy_reader” is a flag representing whether it is a caption easily read by a user or not. “wide_aspect_ratio” is related to a screen ratio, and more particularly, is a flag representing whether a received caption data is intended for a 16:9 screen or not.
If cc_type==0, a received caption is an analog caption. As described above, for the analog caption, there exist an analog caption under the EIA 708 standard, and an analog caption under the SCTE 20 or the DVS 157 standard. However, since the analog caption under the EIA 608 standard is a pure analog caption, not a closed caption for a digital TV mentioned in the present invention, the analog caption under the EIA 608 standard is excluded. Therefore, an analog caption for the case cc_type==0, is either an analog caption under the EIA 708 standard or an analog caption under the SCTE 20 or the DVS 157 standard.
“analog_cc_type” represents whether a received caption is an analog caption under the EIA 708 standard or an analog caption under the SCTE 20 or the DVS 157 standard. If analog_cc_type==0, it means that the relevant caption is included in a video data region in form of user data under the SCTE 20 or the DVS 157, which are standards on the digital cable broadcast. In that case, since to which line of the VBI the received caption is assigned, is not known in view of characteristics of the cable broadcast, the line_offset describes to which line of the VBI the received caption is included. If analog_cc_type==1, it means that an analog caption under the EIA 708 standard is included in a video data region in form of user data. In that case, since the caption is assigned to a 21 st line of the VBI, a line_offset value is not required. Therefore, 5 bits assigned to the line_offset becomes a reserved bit and 1 bit is assigned to the line_field representing whether a caption is a caption included in an even field or a caption included in an odd field. If line_field==0, it means a caption is included in an odd field and if line_field==1, it means a caption is included in an even field.
As described above, whether a caption included in the digital cable broadcast is an analog caption or a digital caption is judged on the basis of information included in the caption_service_descriptor. Further, if the received caption is an analog caption, whether the caption is an analog caption under the EIA 708 standard or a caption for a cable broadcast under the SCTE 20 or the DVS 157 standard, is judged. If the received caption is a caption under the SCTE 20 or the DVS 157 standard, in which line of the VBI the caption data is included, is judged. If the received caption is a digital caption, information as to which service the caption includes among sixty-three services, is checked.
A broadcast station generates caption information including the above described various information and adds the caption information to a broadcast signal. A broadcast receiver detects caption information included in a broadcast signal provided from the broadcast station, and judges various characteristics of the received caption data on the basis of parameter values included in the detected caption information.
FIG. 3 is a block diagram illustrating a construction of a digital broadcast receiver according to the present invention. Referring to FIG. 3 , a MPEG demultiplexer 501 receives a MPEG-2 transport stream from a cable and decodes the transport stream so as to extract video data, audio data, and supplementary information. Further, the MPEG demultiplexer 501 detects an EIT and a PMT included in the supplementary information. The detected PMT is stored in a PMT buffer 502 and the detected EIT is stored in an EIT buffer 503 . Here, the detected PMT or EIT includes caption information, namely, caption_service_descriptor. A controller 504 receives caption information from the PMT buffer 502 or the EIT buffer 503 and detects caption data included in the transport stream on the basis of the caption information. A video parser 505 receives video data decoded by the demultiplexer 501 and separates the video data into user_data and MPEG-2 video data. An analog caption decoder 506 receives user_data from the video parser 505 and detects analog caption data from the user_data on the basis of a signal outputted from the controller 504 . A digital caption decoder 507 receives the user_data from the video parser 505 and detects digital caption data from the user_data on the basis of a signal outputted from the controller 504 . A MPEG-2 video decoder 508 decodes MPEG-2 video data generated by the video parser 505 . A graphic block 510 outputs a signal for generating a GUI (graphic user interface) such as an OSD (on screen display) menu including information provided from the controller 504 . The graphic block 510 displays, on a screen, various characteristics of the received caption data, for example, a number of caption services, a national language of a caption, a type and a standard of the received caption data, VBI line information and field information that correspond to the caption data, a difficulty level of the caption, a picture ratio of the caption. A video combiner 509 receives analog caption data from the analog caption decoder 506 or receives digital caption data from the digital caption decoder 507 . Further, the video combiner 509 receives video data from the MPEG-2 video decoder 508 and receives a signal outputted from the graphic block 510 . The video combiner 509 combines the received signals so as to generate data that will be possibly displayed. A video reconstructor 511 encodes an analog caption data decoded by the analog caption decoder 506 , at a 21 st line of the VBI.
Operation of the digital broadcast receiver as described above according to the present invention will now be described. FIG. 4 illustrates a method for processing a caption according to the present invention.
If a MPEG-2 transport stream transmitted through a cable is received, the MPEG demultiplexer 501 divides the received transport stream into video data, and audio data, supplementary information. The supplementary information includes a PSIP defining electronic program guide (EPG) and system information (SI). The PSIP includes a plurality of tables including information for transmitting/receiving A/V (audio/video) data made in a MPEG-2 video and AC-3 (audio coding-3) audio formats, and information regarding channels of each broadcast station and information regarding each program of channel. Among them, information regarding the PMT and information regarding the EIT are stored in the PMT buffer 502 and the EIT buffer 503 , respectively. Under the ATSC standard, the digital cable broadcast signal must include a caption_service_descriptor in its PMT or EIT.
The controller 504 reads a caption-related option stored in a memory (not shown) and determines a caption-related option selected by a user (S 11 ). For example, the caption-related option includes various options such as “caption off”, “caption service selection (cc1, cc2, cc3, . . . )”, “English caption display”, “Korean caption display”, “size of caption”, “color of caption”. If a user selects “caption off”, the controller 504 does not display the received caption. If a user selects “English caption display”, the controller 504 controls the caption decoders 506 and 507 so that only the caption written in English may be displayed on a screen. Further, the controller 504 controls the caption decoders 506 and 507 so that the received caption data may be processed according to a set size and a set color of a caption.
The controller 504 receives the caption information and judges characteristics of the received caption data on the basis of parameter values included in the caption information (S 12 ). The controller 504 judges a number of caption services on the basis of the caption information. For example, the controller 504 judges whether a synchronous caption, an asynchronous caption service, a letter information service are provided. The controller 504 judges a language of the received caption on the basis of the caption information. For example, the controller 504 judges whether the received caption is English, Japanese, or Korean. The controller 504 judges a type of the received caption data on the basis of the caption information. For example, the controller 504 judges whether the received caption data is digital caption data or analog caption data (S 13 ). The controller 504 determines a standard of the received caption data on the basis of the caption information. For example, if the received caption data is analog caption data, the controller 504 judges whether the received caption data is caption data under the EIA 708 standard or the SCTE 20 or the DVS 157 standard. Further, the controller 504 judges a VBI line number and a field including the received caption, a difficulty level of the received caption, and a picture ratio of the received caption on the basis of the caption information.
To judge whether the received caption data is digital caption data in the step of S 13 , the controller 504 judges whether the digital caption data is included in the video data on the basis of the caption information.
If digital caption data under the EIA 708 is included in the video data (if cc_type==1), the controller 504 detects a service ID that corresponds to the caption data from the caption information (S 14 ) and transmits the detected service ID to the digital caption decoder 507 . The service ID can be known from a capto_service_number included in the caption information. The digital caption decoder 507 extracts and decodes caption data that corresponds to the service ID from user_data of a picture header transmitted from the video parser 505 (S 15 ). Subsequently, the extracted caption data is transmitted to the video combiner 509 . The video combiner 509 combines the extracted caption data, video data outputted from the MPEG-2 video decoder 508 , and signals outputted from the graphic block 510 .
If analog caption data is included in the video data (if cc_type==0), the controller 504 judges whether the received caption data is analog caption data (analog_cc_type==1) under the EIA 708 standard or analog caption data (analog_cc_type==0) under the SCTE 20 or DVS 157 standard (S 16 ). At this point, the controller 504 determines a standard of the received analog caption data on the basis of the caption information.
If the received caption data is analog caption data under the SCTE 20 or the DVS 157, the controller 504 checks VBI line information described in 5 bits by a line_offset included in the caption information. The VBI line information represents a position of the caption data. Further, the controller 504 judges a field where the caption data exists on the basis of line_field information included in the caption information. If line_field==0, the caption data exists in an odd field and if line_field==1, the caption data exists in an even field. After that, the controller 504 transmits the above checked VBI line information and the line field information to the analog caption decoder 506 . If the received caption data is analog caption data, user_data outputted from the video parser 505 is not processed by the digital caption decoder 507 . The analog caption decoder 506 finds out (S 18 ) analog caption data made in the SCTE 20 or the DVS 157 standard from user_data inputted from the video parser 505 on the basis of the VBI line information and the line field information, and decodes the analog caption data (S 19 ). The analog caption data found by the analog caption decoder 506 is transmitted to the video combiner 509 . The video combiner 509 combines the analog caption data, video data outputted from the MPEG-2 video decoder 508 , and signals outputted from the graphic block 510 . Signals outputted from the video combiner 509 are transmitted to the video reconstructor 511 . The video reconstructor 511 reconstructs a caption by encoding analog caption data outputted from the analog caption decoder 506 , at a VBI 21 st line. The reconstruction of a caption is to prevent analog caption data from being an open caption in case of storing data, as it is, outputted from the video combiner 509 in a storage medium such as a VCR (video cassette recorder).
If the received caption data is analog caption data under the EIA 708 standard (if analog_cc_type==1), the controller 504 transmits line_field information included in the caption information to the analog caption decoder 506 . Since analog caption data under the EIA 708 standard is positioned at a VBI 21 st line, a line_offset value is not required. At this point, the digital caption decoder 507 extracts a 2-byte analog data in user_data including digital caption data from the video parser 505 and transmits the analog data to the analog caption decoder 506 . Subsequently, the analog caption decoder 506 finds out (S 17 ) analog caption data present in a VBI 21 st line from the 2-byte analog data on the basis of the line_field information and decodes the analog caption data (S 19 ). The found analog caption data is combined with video data from the MPEG-2 video decoder 508 and signals from the graphic block 510 by the video combiner 509 . The video reconstructor 511 reconstructs a caption by encoding analog caption data from the analog caption decoder 506 at a VBI 21 st line.
If analog caption data under the EIA 708 and analog caption data under the SCTE 20 and the DVS 157 are all present in the user_data, the analog caption data under the EIA 708 is processed. Further, if digital caption data under the EIA 708 and analog caption data under the EIA 708 are all present in the user_data, the digital caption data is processed.
As described above, the present invention judges a type of caption data on the basis of caption information included in the received broadcast signal and automatically processes the caption data according to the type, thereby providing convenience to a user. Further, the present invention judges various characteristics of the received caption data such as a standard of caption data, a number of caption services being received and provides the characteristics to a user. Furthermore, the present invention can store caption-related options selected by a user and display the caption being received according to the caption-related options.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A digital cable broadcast receiver and a method for automatically processing caption data of various standards and types, is disclosed. The digital broadcast receiver includes: a demultiplexer for dividing a received broadcast stream into video data, audio data, supplementary information; a controller for determining whether caption data included in the video data is digital caption data or analog caption data on the basis of caption information included in the supplementary information, and outputting a control signal according to a result of the determining; a digital caption decoder for extracting and decoding digital caption data from the video data according to the control signal; and an analog caption decoder for extracting and decoding analog caption data from the video data according to the control signal.
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FIELD OF THE INVENTION
The present invention relates to sulfur containing fluoroalkyl amines, methods for making the same, and isocyanate/isothiocyanate derivatives of the same.
BACKGROUND OF THE INVENTION
Sulfur containing fluoroalkyl amines are useful as intermediates for compounds which are in turn useful for imparting water and oil repellency to textiles. Sulfur containing fluoroalkyl amines used in this manner may be found in Example 8 of Rondestvedt et al. (U.S. Pat. No. 3,655,732) wherein they are made by reacting an iodo-fluoroalkyl with an aminoalkyl thiol. Specifically, Rondestvedt et al. teaches reacting CF 3 (CF 2 ) 5 (CH 2 ) 2 I (an iodo-fluoroalkyl) with HS—CH 2 CH 2 —NH 2 (an aminoalkyl thiol) to make CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 CH 2 —NH 2 (a sulfur containing fluoroalkyl amine).
One disadvantage of preparing sulfur containing fluoroalkyl amines according to the method disclosed by Rondestvedt et al. is that crude product obtained by such a method can contain up to 29 mole percent of impurities. To increase yield and reduce the amount of these impurities, tert-butanol has been used as reaction solvent ( J. Org. Chem. 1977, 42, 2680-2683); however, tert-butanol is relatively expensive and subsequent isolation of the product can be unpredictably tedious due to foam and emulsion formation.
In addition to problems of poor yield, another disadvantage of preparing sulfur containing fluoroalkyl amines according to the method disclosed by Rondestvedt et al. is that such a method is incapable of producing oxidized forms of sulfur containing fluoroalkyl amines. While Rondestvedt et al. disclose a method of making sulfur containing fluoroalkyl amines such as CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 CH 2 —NH 2 , the method of Rondestvedt et al. cannot produce corresponding oxidized forms such as CF 3 (CF 2 ) 5 (CH 2 ) 2 —S(O)—CH 2 CH 2 —NH 2 or CF 3 (CF 2 ) 5 (CH 2 ) 2 —S(O) 2 —CH 2 CH 2 —NH 2 .
BRIEF SUMMARY OF THE INVENTION
The present invention provides a method of making sulfur containing fluoroalkyl amines which overcomes the problems of previously known methods such as the one described by Rondestvedt. For example, unlike previously known methods, the method of the present invention can achieve higher yields of sulfur containing fluoroalkyl amines without resorting to costly solvents. Furthermore, unlike previously known methods, the method of the present invention can produce oxidized forms of sulfur containing fluoroalkyl amines wherein the sulfur atom thereof is oxidized.
In the method of the present invention, a fluoroalkyl thiol is reacted with a N-vinylamide resulting in an amide intermediate which is then subjected to deacylation to make corresponding sulfur containing fluoroalkyl amine. Optionally, the amide intermediate can be subjected to oxidation prior to deacylation thereby producing an oxidized form of sulfur containing fluoroalkyl amines wherein the sulfur atom thereof is oxidized.
Fluoroalkyl thiols useful in the present invention are represented by R f -Q-SH wherein R f is chosen from a C 2 -C 12 perfluoroalkyl provided that: i) one fluorine atom of the perfluoroalkyl can be optionally replaced by hydrogen, and/or ii) the perfluoroalkyl can be optionally interrupted by at least one oxygen, methylene, or ethylene; Q is chosen from the group consisting of a C 2 -C 12 hydrocarbylene optionally interrupted by at least one divalent organic group.
N-Vinylamides useful in the present invention are represented by H 2 C═CH—(CH 2 ) y —NR—C(O)—R wherein y is an integer chosen from 0 to 16, preferably 1, and most preferably 0; and each R is independently chosen from H or a C 1 to C 4 alkyl, preferably methyl, and most preferably H.
When the aforementioned fluoroalkyl thiols and the aforementioned N-vinylamides are reacted, in accordance with the present invention, the result is an amide intermediate of the present invention represented by R f -Q-S—C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NR—C(O)—R wherein each R is independently chosen from H or a C 1 to C 4 alkyl, preferably methyl, and most preferably H; i is 1 or 2, j is 0 or 1; provided that i+j=2. More preferably i=1, j=1, and z=O, Still even more preferably i=2, j=0, and z=0.
Except where otherwise noted, the aforementioned definitions for R f , Q, R, i, j, y and z are applied consistently throughout the specification and claims.
The amide intermediate of the present invention can be subjected to deacylation to produce a sulfur containing fluoroalkyl amine represented by R f -Q-S—C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NHR wherein R is chosen from H or a C 1 to C 4 alkyl, preferably methyl, and most preferably H. Optionally, prior to removal of the acyl group, the amide intermediate of the present invention can be subjected to oxidation to produce a sulfur oxide intermediate of the present invention represented by R f -Q-S(O) x —C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NR—C(O)—R wherein x is 1 or 2. Except where otherwise noted, the aforementioned definition x is used consistently throughout the specification and claims. The sulfur oxide intermediate can then be subjected to deacylation to produce a sulfur containing fluoroalkyl amine of the present invention represented by R f -Q-S(O) x —C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NHR. Previously known methods were not capable of making sulfur containing fluoroalkyl amines having the —S(O) x — moiety.
Advantageously, the amide intermediate of the present invention of the present invention represented by R f -Q-S—C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NR—C(O)—R can be subjected to oxidation such that the sulfur atom thereof is selectively oxidized while the amide group, NR—C(O)—R, remains unoxidized. After oxidation, deacylation can be conducted to convert the amide group, NR—C(O)—R, into an amine group, —NHR, thereby resulting in a sulfur containing fluoroalkyl amine wherein the sulfur thereof is oxidized. Previously known methods do not form any intermediate wherein the sulfur atom thereof can be selectively oxidized. In contrast to the present invention, previously known methods only make compounds wherein both a sulfur group, —S—, and an amine group, —NHR, are present thereby rendering the selective oxidation of the sulfur group impossible because of the potential oxidation of the amine group.
DETAILED DESCRIPTION OF THE INVENTION
Unless otherwise stated, the R f moiety referred to throughout this disclosure is chosen from a C 2 -C 12 perfluoroalkyl provided that: i) the perfluoroalkyl can be optionally interrupted by at least one oxygen, methylene, or ethylene; and/or ii) one fluorine atom of the perfluoroalkyl can be optionally substituted by one hydrogen when the perfluoroalkyl is not interrupted by methylene or ethylene. Examples of R f moieties which are chosen from a perfluoroalkyl without substitutions or interruptions include (CF 3 ) 2 CF, and CF 3 (CF 2 ) m wherein m is an integer from 1 to 11. Examples of R f moieties which are chosen from a perfluoroalkyl substituted by one hydrogen include (CF 3 ) 2 CH, CF 3 (CF 2 ) 2 OCFHCF 2 , and HC m F 2m wherein m is 2 to 12. Examples of R f moieties which are chosen from a perfluoroalkyl which is interrupted by at least one oxygen include CF 3 (CF 2 ) 2 OCF 2 CF 2 and CF 3 (CF 2 ) 2 OCFHCF 2 , and CF 3 CF 2 CF 2 [OCF(CF 3 )CF 2 ] m OCRF wherein m is an integer from 6 to 15 and R can be F, CF 3 , or H. Examples of R f moieties which are chosen from a C 2 -C 12 perfluoroalkyl which is interrupted by at least one methylene include CF 3 (CF 2 ) 3 (CH 2 CF 2 ) m and CF 3 (CF 2 ) 5 (CH 2 CF 2 ) m wherein m is 1, 2, or 3. Examples of R f moieties which are chosen from a perfluoroalkyl which is interrupted by at least one ethylene include F[(CF 2 CF 2 ) n (CH 2 CH 2 ) m ] k CF 2 CF 2 wherein n=1, 2, or 3 preferably 1; and m=1, or 2 preferably 1; and k=1, 2, or 3.
Unless otherwise stated, the term “fluoroalkyl thiol” or “thiol” as used throughout this disclosure means a compound represented by R f -Q-SH wherein Q is chosen from the group consisting of a C 2 -C 12 hydrocarbylene optionally interrupted by at least one divalent organic group. The fluoroalkyl thiols useful in the present invention can be made by any known method. For example, Lantz (U.S. Pat. No. 4,845,300) discloses the following reaction scheme for making thiols useful for the present invention: R f CH 2 CH 2 I+S═C(NH 2 ) 2 →[R f CH 2 CH 2 S—(NH 2 ) 2 ] + I 31 +NaOH→R f CH 2 CH 2 SH+NaI+O═C(NH 2 ) 2 +MeOH wherein R f is defined therein. Alternatively, Jacobson (U.S. Pat. No. 5,728,887) discloses hydrogenation for making thiols useful for the present invention: R f CH 2 CH 2 SCN+H 2 →R f CH 2 CH 2 SH+HCN wherein R f is defined therein. Alternatively, a thioacetate intermediate ( J. Fluorine Chem. 2000, 104, 173-183) can be used according to the following reaction: R f CH 2 CH 2 I+KSOCMe→(saponification)→R f CH 2 CH 2 SH+KOAc.
Unless otherwise stated, the N-vinylamides referred to throughout this disclosure and useful in the present invention are represented by H 2 C═CH—(CH 2 ) y —NR—C(O)—R wherein y is an integer chosen from 0 to 16, preferably 1, and most preferably 0; and each R is independently chosen from H or a C 1 to C 4 alkyl, preferably methyl, and most preferably H. N-Vinylamides useful in the present invention include well known compounds which are commercially available such as N-vinylformamide, N-vinylacetamide, N-vinyl-N-methyl-acetamide, N-vinylpyrrolidone, and N-allyl formamide.
In the method of the present invention, a fluoroalkyl thiol is reacted with a N-vinylamide resulting in an amide intermediate which is then subjected to deacylation to make a corresponding sulfur containing fluoroalkyl amine. Optionally, the amide intermediate can be subjected to oxidation prior to deacylation thereby producing an oxidized form of sulfur containing fluoroalkyl amines wherein the sulfur atom thereof is oxidized.
Unless otherwise stated, the amide intermediates referred to throughout this disclosure are represented by R f -Q-S—C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NR—C(O)—R wherein each R is independently chosen from H or a C 1 to C 4 alkyl, preferably methyl, and most preferably H. The amide intermediates of the present invention are made by reacting a fluoroalkyl thiol, R f -Q-SH, with a N-vinylamide, H 2 C═CH—(CH 2 ) y —NR—C(O)—R.
Specifically, the amide intermediates of the present invention can be made by the free-radical addition of a fluoroalkyl thiol, R f -Q-SH, to a N-vinylamide, H 2 C═CH—(CH 2 ) y —NR—C(O)—R. Reaction conditions for free-radical conditions are well known in the art. An example of a method for conducting free-radical addition involves dissolving one equivalent of a chosen thiol, one equivalent of a chosen N-vinylamide, and an initiator. The solution is then heated to a temperature (typically about 65° C.) which activates the reaction which is stirred until complete consumption of the thiol as determined by gas chromatography-mass spectrometry (GC/MS) monitoring.
Useful initiators for free-radical addition are well known in the art and include: azo compounds, such as azobisisobutyronitrile and azo-2-cyanovaleric acid; hydroperoxides, such as cumene, t-butyl and t-amyl hydroperoxide; dialkyl peroxides, such as di-t-butyl and dicumylperoxide; peroxyesters, such as t-butylperbenzoate and di-t-butylperoxy phthalate; and diacylperoxides, such as benzoyl peroxide and lauryl peroxide; peroxide such as persulfate; and metals such copper. Examples of useful organic solvents for free-radical addition include: ethers, such as tetrahydrofuran, dimethoxyethane, 1,4-dioxane; acetates, such as ethyl acetate, butyl acetate, and isopropyl acetate; alcohols, such as 2-methanol, ethanol, methylpropan-2-ol, isopropanol, 2-methoxyethanol (monoglyme), 2-methoxypropan-2-ol; and ketones, such as acetone, methylisobutyl ketone, and methylethyl ketone, such as N-methyl-2-pyrrolidone, and mixtures thereof. Also hydrocarbon solvents such as toluene are suitable.
As an alternative to free-radical addition, the amide intermediates of the present invention can be made by the Michael addition of a fluoroalkyl thiol, R f -Q-SH, to a N-vinylamide, H 2 C═CH—(CH 2 ) y —NR—C(O)—R, using catalytic amounts of a base, such as tertiary ammonium hydroxide or sodium hydride.
The sulfur oxide intermediates of the present invention are made by the oxidation of an amide intermediate using an oxidizing agent, such as peroxides. The oxidation may optionally include catalysts such as sodium tungstate, phenyl phosphonate, trioctylmethyl ammonium bisulfate, and mixtures thereof. When such catalysts are used during oxidation, the —S(O) x — moiety of the resulting sulfur oxide intermediate is —S(O) 2 —. One example us the use of such catalyst is in Tetrahedron 2005, 61, 8315-8327 and Sato et al. reference [27] therein. When no catalysts are used during oxidation, the —S(O) x — moiety of the resulting sulfur oxide intermediate is —S(O)—. An example of a method for conducting oxidation of an amide intermediate involves adding about one mol equivalent of an oxidizing agent (preferably hydrogen peroxide) to about one mol equivalent of an amide intermediate (optionally in the presence of catalyst) in solvent (preferably an alcohol such as ethanol) at a low temperature (typically about 0° C.) and stirring the mixture while allowing to warm (typically to about 50-60° C.) to activate the oxidation reaction. The progress of the reaction can be monitored via gas chromatography. Upon complete conversion (about 5 hours) any excess oxidizing agent is destroyed; for example hydrogen peroxide can be destroyed with a solution of sodium sulfite. The solvent can then be removed by distillation and the resulting residue containing crude product can be washed (e.g. with water) and dried in vacuum.
The sulfur containing fluoroalkyl amines of the present invention can be made by deacylation of an amide intermediate or a sulfur oxide intermediate. Deacylation of an amide intermediate can be performed by acid catalyzed or base catalyzed deacylation. Deacylation of a sulfur oxide intermediate can be performed by acid catalyzed deacylation.
Acid catalyzed deacylation can be conducted by adding to an amide intermediate or a sulfur oxide intermediate in solvent (preferably an alcohol such as ethanol) at a low temperature (typically 0° C.), a molar excess (typically about a six-fold excess) of concentrated acid (e.g. hydrochloric acid). This mixture is stirred and allowed to warm to ambient temperature and after an initial formation of foam the reaction mixture is slowly heated and held at reflux temperature (about 85° C.) for about 5 hours. The progress of the reaction can be monitored via gas chromatography. Upon complete conversion, the pH of the solution is brought to about 8-10 by carefully adding aqueous base (e.g. sodium hydroxide solution). The resulting sulfur containing fluoroalkyl amine in crude form separates as a bottom layer and can be isolated, e.g. with a separatory funnel. Alternatively, if the ammonium salt is desired, no aqueous base is added.
Base catalyzed deacylation can be conducted by adding an excess (typically about a five-fold excess) of concentrated base (e.g. sodium hydroxide) to the amide intermediate in solvent (preferably an alcohol such as ethanol) at a low temperature (typically 0° C.). This mixture is stirred and allowed to warm to ambient temperature and the reaction mixture is slowly heated and held at reflux temperature (about 85° C.) for about 8 hours. The progress of the reaction can be monitored via gas chromatography. The resulting sulfur containing fluoroalkyl amine in crude form separates as a bottom layer and can be isolated, e.g. via a separatory funnel.
One of the advantages of the formation of an amide intermediate of the present invention, R f -Q-S—C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NR—C(O)—R, is that the sulfur atom therein can be selectively oxidized while the acyl group —C(O)—R is remains unoxidized thereby forming a sulfur oxide intermediate represented by R f -Q-S(O) x —C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NR—C(O)—R wherein x is 1 or 2. The sulfur oxide intermediate can then be subjected to deacylation to convert the amide group, NR—C(O)—R, into an amine group, —NHR, thereby resulting in a sulfur containing fluoroalkyl amine wherein the sulfur thereof is oxidized. Previously known methods do not form any intermediate wherein the sulfur atom thereof can be selectively oxidized. In contrast to the present invention, previously known methods only make compounds wherein both a sulfur group —S— and an amine group —NHR (R is chosen from H or a C 1 to C 4 alkyl, preferably methyl, and most preferably H) are present thereby rendering the selective oxidation of the sulfur group impossible because of the potential oxidation of the amine group.
Accordingly, it was previously unknown how to make a sulfur containing fluoroalkyl amine of the present invention represented by R f -Q-S(O) x —CH 2 —C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —NH 2 wherein:
R f is chosen from a C 2 -C 12 perfluoroalkyl provided that: i) one fluorine atom of the perfluoroalkyl can be optionally replaced by hydrogen, and/or ii) the perfluoroalkyl can be optionally interrupted by at least one oxygen, methylene, or ethylene;
Q is chosen from the group consisting of a C 2 -C 12 hydrocarbylene optionally interrupted by at least one divalent organic group; and
x is 1 or 2;
z is 0 or 1;
i is 1 or 2, j is 0 or 1; provided that i+j=2.
It was also previously unknown how to make isocyante and isothiocyante derivatives of the sulfur containing fluoroalkyl amine of the present invention, said isocyante and isothiocyante derivatives represented by R f -Q-S(O) x —C(H) i (CH 3 ) j —(CH 2 ) z+(i−1) —N═C═X 1 wherein:
X 1 is O or S;
R f is chosen from a C 2 -C 12 perfluoroalkyl provided that: i) one fluorine atom of the perfluoroalkyl can be optionally replaced by hydrogen, and/or ii) the perfluoroalkyl can be optionally interrupted by at least one oxygen, methylene, or ethylene;
Q is chosen from the group consisting of a C 2 -C 12 hydrocarbylene optionally interrupted by at least one divalent organic group; and
x is 1 or 2;
z is 0 or 1;
i is 1 or 2, j is 0 or 1; provided that i+j=2.
Isocyante and isothiocyante derivatives of the sulfur containing fluoroalkyl amine of the present invention can be made be made by any suitable process which converts a primary amine group (—NH 2 ) to an isocyanate group (—N═C═O) or isothiocyante group (—N═C═S). An example of a method of converting a primary amine group (—NH 2 ) to an isocyanate group (—N═C═O) may be found in Kornek et al. (DE10108543) consistent with the following reaction scheme: R f —CH 2 CH 2 —S—CH 2 CH 2 —NH 2 +EtOC(O)Cl+Cl 3 SiMe+2 NEt 3 →R f —CH 2 CH 2 —S—CH 2 CH 2 —N═C═O+EtOSi(Me)Cl 2 +2 Et 3 NHCl. An example of a method of converting a primary amine group (—NH 2 ) to an isothiocyante group (—N═C═S) may be found in J. Org. Chem. 1956, 21, 404-405 consistent with the following reaction scheme: R f —CH 2 CH 2 —S—CH 2 CH 2 —NH 2 +CS 2 +EtOC(O)Cl+2 NEt 3 →R f —CH 2 CH 2 —S—CH 2 CH 2 —N═C=S+COS+EtOH+2 Et 3 NHCl.
EXAMPLES
Table 1 below shows the fluoroalkyl thiols used throughout the examples numbered as Thiol #1, Thiol #2, and Thiol #3. Table 2 below shows amide intermediates made from the thiols in Table 1. Table 3 shows sulfur oxide intermediates made from the amide intermediates of Table 2. Table 4 shows sulfur containing fluorinated amines made from the amide intermediates or sulfur oxide intermediates which are labeled Fluorinated Amine #1, Fluorinated Amine #2, Fluorinated Amine #3, and Fluorinated Amine #4. Table 4 also shows a sulfur containing fluorinated amine salt labeled Fluorinated Amine Salt #1. Table 4 further shows isocyante and isothiocyante derivatives which respectively labeled Fluorinated Isocyanate #1 and Fluorinated Isothiocyanate #1.
TABLE 1
Thiol
IUPAC Name
Structure
Thiol #1
3,3,4,4,5,5,6,6,7,7,8,8,8-
CF 3 (CF 2 ) 5 (CH 2 ) 2 SH
tridecafluoro-octane-1-thiol
Thiol #2
3,3,4,4-tetrafluoro-4-
CF 3 (CF 2 ) 2 O(CF 2 ) 2 (CH 2 ) 2 SH
heptafluoropropyloxy-butane-
1-thiol
Thiol #3
3,3,5,5,6,6,7,7,8,8,8-
CF 3 (CF 2 ) 3 CH 2 CF 2 (CH 2 ) 2 SH
undecafluoro-octane-1-thiol
TABLE 2
Made
from this
Amide Intermediate
Structure
Thiol
Made from this N-vinyl amide
Amide Intermediate #1A
CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 —CH 2 —NH—C(O)—CH 3
Thiol #1
CH 2 ═CH—NH—C(O)—CH 3
Amide Intermediate #1B(*)
CF 3 (CF 2 ) 5 (CH 2 ) 2 S—CH 2 —CH 2 —N(CH 3 )—C(O)—CH 3
Thiol #1
CH 2 ═CH—N(CH 3 )—C(O)—CH 3
CF 3 (CF 2 ) 5 (CH 2 ) 2 S—CH(CH 3 )—N(CH 3 )—C(O)—CH 3
Amide Intermediate #1C
CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 —CH 2 —NH—C(O)—H
Thiol #1
CH 2 ═CH—NH—C(O)—H
Amide Intermediate #1D
Thiol #1
Amide Intermediate #2
CF 3 (CF 2 ) 2 O(CF 2 ) 2 (CH 2 ) 2 S—CH 2 —CH 2 —NH—C(O)—H
Thiol #2
CH 2 ═CH—NH—C(O)—H
Amide Intermediate #3
CF 3 (CF 2 ) 3 CH 2 CF 2 (CH 2 ) 2 S—CH 2 —CH 2 —NH—C(O)—H
Thiol #3
CH 2 ═CH—NH—C(O)—H
(*)isomeric mixture of N-methyl-N-[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethyl]-acetamide and (R,S)-N-methyl-N-[1-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethyl]-acetamide
TABLE 3
Made from oxidation of Amide
Sulfur oxide intermediate
Structure
Intermediate
Sulfur oxide intermediate #1A
CF 3 (CF 2 ) 5 (CH 2 ) 2 —S(O)—CH 2 —CH 2 —NH—C(O)—H
Amide Intermediate #1C
Sulfur oxide intermediate #1B
CF 3 (CF 2 ) 5 (CH 2 ) 2 —S(O) 2 —CH 2 —CH 2 —NH—C(O)—H
Amide Intermediate #1C
TABLE 4 Ex. Product Structure Intermediate used to make product 1 Fluorinated Amine #1 CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 —CH 2 —NH 2 Amide Intermediate #1A* 2 Amide Intermediate #1C* 3 Amide Intermediate #1A** 4 Amide Intermediate #1C** 5 Fluorinated Amine #2 CF 3 (CF 2 ) 5 (CH 2 ) 2 —S(O)—CH 2 —CH 2 —NH 2 Sulfur oxide intermediate #1A* 6 Fluorinated Amine #3 CF 3 (CF 2 ) 5 (CH 2 ) 2 —S(O) 2 —CH 2 —CH 2 —NH 2 Sulfur oxide intermediate #1B* 7 Fluorinated Amine #4 CF 3 (CF 2 ) 2 O(CF 2 ) 2 (CH 2 ) 2 S—CH 2 —CH 2 —NH 2 Amide Intermediate #2* 8 Fluorinated Amine Salt #1 [CF 3 (CF 2 ) 3 CH 2 CF 2 (CH 2 ) 2 S—CH 2 —CH 2 —NH 3 + ]Cl − Amide Intermediate #3 9 Fluorinated Isocyanate #1 CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 —CH 2 —N═C═O Fluorinated Amine #1 10 Fluorinated Isothiocyanate #1 CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 —CH 2 —N═C═S Fluorinated Amine #1 *made by procedure for acid catalyzed deacylation **made by procedure for base catalyzed deacylation
Thiol #1
Thiol #1 was 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octane-1-thiol which was made as follows. Under nitrogen thiourea (1.1 equivalents) and 1-iodo-2-perfluorohexylethane (1 equivalent) were added to a degassed mixture of dimethoxyethane (DME, 9 parts) and water (1 part). The reaction mixture was held at reflux temperature for 8 hours. Most of the DME was distilled off and the distillation residue was allowed to cool to ambient temperature. Under stirring a solution of sodium methoxide in methanol (1 molar, 1.1 equivalents) was added to the suspension. Degassed water was added to the mixture. Thiol #1 was collected quantitatively as the fluorous bottom layer.
The spectroscopical data for the product were in agreement with those published elsewhere ( J. Fluorine Chem. 1985, 28, 341-355 and J. Fluorine Chem. 1989, 42, 59-68).
Thiol #2
Thiol #2 was 3,3,4,4-tetrafluoro-4-heptafluoropropyloxy-butane-1-thiol which was made as follows. 1,1,1,2,2,3,3-heptafluoro-3-[(1,2,2-trifluoroethenyl)oxy]-propane (available from E. I. du Pont de Nemours and Company as PPVE) was reacted with iodine monochloride and subsequently treated with boron trifluoride to furnish 1,1,1,2,2,3,3-heptafluoro-3-[(1-iodo-1,1,2,2-trifluoroethenyl)oxy]-propane (U.S. Pat. No. 5,481,028A). 1,1,1,2,2,3,3-Heptafluoro-3-[(1-iodo-1,1,2,2-trifluoroethenyl)oxy]-propane was then reacted with ethylene in the presence of a peroxide initiator to yield 1,1,2,2-tetrafluoro-1-(1,1,2,2,3,3,3-heptafluoropropyloxy)-4-iodo-butane (US20080113199A1). Under nitrogen, thiourea (1.1 equivalents) and 1,1,2,2-tetrafluoro-1-(1,1,2,2,3,3,3-heptafluoropropyloxy)-4-iodo-butane were added to degassed 1,4-dioxane. The reaction mixture was heated at reflux temperature for 8 hours. The dioxane was distilled off and the distillation residue was allowed to cool to ambient temperature. Under stirring, a thoroughly degassed solution of sodium hydroxide in methanol and water 1:1 (1 molar, 1.1 equivalents) was added to the suspension. The mixture was heated at 50-60° C. for 5 hours. Additional degassed water was added to the mixture. Thiol #2 was collected quantitatively as the fluorous bottom layer and purified via distillation. NMR of Thiol #2 was obtained as follows.
1 H-NMR (CDCl 3 ): 1.60 (t, J=17 Hz, 1H, SH), 2.45 (m, 2H, CF 2 CH 2 ), 2.86 (m, 2H, CH 2 S).
Thiol #3
Thiol #3 was 3,3,5,5,6,6,7,7,8,8,8-undecafluoro-octane-1-thiol which was made as follows. Under nitrogen, potassium thioacetate (1.1 equivalents) was added to a solution of 1,1,1,2,2,3,3,4,4,6,6-undecafluoro-8-iodo-octane (1 equivalent) in THF. The reaction mixture was stirred at 50° for 5 hours. The THF was removed under reduced pressure. The distillation residue was dissolved in methanol (25 mL/0.1 mol) and treated with hydrochloric acid (37 w/% in water, three fold excess). Additional degassed water was added to the mixture. Thiol #3 was collected as the fluorous bottom layer and purified via distillation. NMR of Thiol #3 was obtained as follows.
1 H-NMR (CDCl 3 ): 1.55 (s, br, 1H, SH), 2.32 (m, 2H, CF 2 CH 2 ), 2.74 (m, 4H, CH 2 S and CF 2 CH 2 CF 2 ).
Table 1
The following table shows the thiols that were made above.
Thiol #1
Procedure for Amide Intermediate Synthesis
When amide intermediate synthesis was used to make a chosen amide intermediate in the examples below, amide intermediate synthesis was conducted in the following manner. All amide intermediates in the examples were made according to the following procedure. A solution of one equivalent of a chosen thiol, one equivalent of a chosen N-vinylamide, and 0.04 parts (mol equivalents) VAZO 64 (available from E. I. du Pont de Nemours and Company of Wilmington, Del., USA) in inhibitor-free tetrahydrofuran (THF) was slowly warmed to 65° C. At about 45° C. an exotherm occurred, increasing the reaction temperature briefly to 70° C. The reaction was stirred at 65° C. until complete consumption of the thiol was indicated as determined by gas chromatography-mass spectrometry (GC/MS) monitoring for 5 hours.
Amide Intermediate #1A
Amide Intermediate #1A was N-[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethyl]-acetamide which was made using amide intermediate synthesis wherein Thiol #1 was the chosen thiol and N-vinylacetamide was the chosen N-vinylamide. All volatiles were removed under reduced pressure to furnish the desired crude amide free of its regioisomer as a light orange oil. NMR of Amide Intermediate #1A was obtained as follows.
1 H-NMR (CDCl 3 ): 1.98 (s, 3H, COCH 3 ), 2.36 (m, 2H, CF 2 CH 2 ), 2.70 (m, 4H, CH 2 SCH 2 ), 3.43 (m, 2H, CH 2 N), 5.98 (s, br, 1H, NH).
Amide Intermediate #1B
Amide Intermediate #1B was an isomer mixture of N-methyl-N-[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethyl]-acetamide (I) and (R,S)—N-methyl-N-[1-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethyl]-acetamide (II) which was made using amide intermediate synthesis wherein Thiol #1 was the chosen thiol and N-vinyl-N-methyl-acetamide was the chosen N-vinylamide. All volatiles were removed under reduced pressure to furnish crude Amide Intermediate #1B as a mixture of regioisomers of I and II (3:2) as a light orange oil. The crude Amide Intermediate #1B was about 99% pure and was suitable for further use without further purification. The isomers were not separated. NMR of Amide Intermediate #1B was obtained as follows.
1 H-NMR (CDCl 3 ): (I): 1.98 (s, 3H, COCH 3 ), 2.35 (m, 2H, CF 2 CH 2 ), 2.68 (m, 4H, CH 2 SCH 2 ), 2.96 (s, 3H, NCH 3 ), 3.47 (m, 2H, CH 2 N); (II): 2.03 (s, 3H, COCH 3 ), 2.35 (m, 2H, CF 2 CH 2 ), 2.65 (m, 5H, CF 2 CH 2 CH 2 S and CHCH 3 ), 2.80 (s, 3H, NCH 3 ), 3.43 (m, 1H, CHN).
Amide Intermediate #1C
Amide Intermediate #1C was N-[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethyl]-formamide which was made using amide intermediate synthesis wherein Thiol #1 was the chosen thiol and N-vinylformamide was the chosen N-vinylamide. All volatiles were removed under reduced pressure to furnish the desired amide as an off-white solid. NMR of Amide Intermediate #1C was obtained as follows.
1 H-NMR (CDCl 3 ): 2.33 (m, 2H, CF 2 CH 2 ), 2.70 (m, 4H, CH 2 SCH 2 ), 3.39 (m, 1H, 3.42 (m, 2H, CH 2 N), 6.66 (s, br, 1H, NH), 8.12 (s, 1H, CHO).
Amide Intermediate #1D
Amide Intermediate #1D was 1-[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethyl]-pyrrolidin-2-one which was made using amide intermediate synthesis wherein Thiol #1 was the chosen thiol and N-vinylpyrrolidone was the chosen N-vinylamide. All volatiles were removed under reduced pressure to furnish the desired amide as an off-white solid (Mp 64° C.). NMR of Amide Intermediate #1D was obtained as follows.
1 H-NMR (CDCl 3 ): 2.02 (m, 2H, CH 2 CH 2 CH 2 ), 2.37 (m, 4H, CF 2 CH 2 and CH 2 C═O), 2.71 (m, 2H, SCH 2 CH 2 N), 2.77 (m, 2H, CF 2 CH 2 CH 2 S), 3.41 (m, 1H, 3.42 (m, 2H, SCH 2 CH 2 N), 3.48 (m, 1H, 3.42 (m, 2H, NCH 2 CH 2 CH 2 ).
Examples 1-4
In examples 1-4 below, Fluorinated Amine #1 was 2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octylsulfanyl)-ethylamine and was made by the deacylation of an amide intermediate as indicated. The NMR obtained in the examples below for Fluorinated Amine #1 is represented as follows.
1 H-NMR (CDCl 3 ): 1.28 (br, 2H, NH 2 ), 2.38 (m, 2H, CF 2 CH 2 ), 2.65 (m, 2H, SCH 2 ), 2.73 (m, 2H, CH 2 S), 2.89 (m, 2H, CH 2 N).
1 H-NMR (DMSO-d 6 ): 1.46 (br, 2H, NH 2 ), 2.48 (m, 2H, CF 2 CH 2 ), 2.58 (m, 2H, SCH 2 ), 2.72 (m, 4H, CH 2 S and CH 2 N).
13 C-NMR (CDCl 3 ): 22.3 (s, CH 2 S), 32.1 (m, CF 2 CH 2 ), 35.8 (s, SCH 2 ), 40.5 (s, CH 2 N).
Procedure for Acid Catalyzed Deacylation
When acid catalyzed deacylation was used to make a chosen fluorinated amine in the examples below, acid catalyzed deacylation was conducted in the following manner. Concentrated hydrochloric acid solution (37.5 w/% in water, five to six-fold molar excess) was added to a solution of one equivalent of a chosen amide intermediate in ethanol at 0° C. The reaction mixture was allowed to warm to ambient temperature while being stirred. After the initial foam formation ceased the reaction mixture was slowly heated and held at reflux temperature for 5 hours at about 85° C. The progress of the reaction was monitored via Gas Chromatography. Upon complete conversion, the pH of the solution was brought to 8-10 by carefully adding aqueous sodium hydroxide solution. The chosen fluorinated amine in crude form separated as the bottom layer and was isolated as a brownish slightly viscous liquid via a separatory funnel. The aqueous phase was extracted with diethyl ether. The residue of the dried ether phase was combined with the initial first crop. The chosen fluorinated amine in crude form was washed with water and dried using molecular sieves (4 Å) and was purified by distillation to obtain a colorless liquid in 80 to 95% yield as either a colorless solid or pail yellow liquid.
Example #1
Fluorinated Amine #1 was made by the acid catalyzed deacylation of Amide Intermediate #1A.
Example #2
Fluorinated Amine #1 was made by the acid catalyzed deacylation of Amide Intermediate #1C.
Procedure for Base Catalyzed Deacylation
When base catalyzed deacylation was used to make a chosen fluorinated amine in the examples below, base catalyzed deacylation was conducted in the following manner. An aqueous solution of sodium hydroxide (five equivalents) was added to one equivalent of the chosen fluorinated amine at ambient temperature and the mixture was slowly brought to reflux temperature. After about 8 hours of reaction time, the chosen fluorinated amine in crude form separated as the bottom layer and was isolated as a brownish slightly viscous liquid via a separatory funnel. It was washed with water and dried using molecular sieves (4 Å). The chosen fluorinated amine in crude form was purified by distillation and obtained as a colorless liquid in 80 to 95% yield as either a colorless solid or a pail yellow liquid.
Example #3
Fluorinated Amine #1 was made by the base catalyzed deacylation of Amide Intermediate #1A.
Example #4
Fluorinated Amine #1 was made by the base catalyzed deacylation of Amide Intermediate #1C.
Sulfur Oxide Intermediate #1A
Sulfur oxide intermediate #1A was N-[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octane-1-sulfinyl)-ethyl]-formamide which was made by oxidation of Amide Intermediate #1C as follows. Hydrogen peroxide (35 w/% in water, 1.1 mol equivalents) was added to a solution of one equivalent of Amide Intermediate #1C in ethanol at 0° C. The reaction mixture was allowed to warm to ambient temperature while being stirred. The progress of the reaction was monitored via Gas Chromatography. Upon complete conversion (5 hours) any excess peroxide was destroyed by adding a solution of sodium sulfite (negative peroxide test). The ethanol was distilled off; the residue was washed with water and dried in vacuum. The Sulfur oxide intermediate #1 was obtained quantitatively as a colorless solid. Mp 179° C. NMR of Sulfur oxide intermediate #1A was obtained as follows.
1 H-NMR (CDCl 3 ): 2.59 (m, 2H, CF 2 CH 2 ), 2.93 (dm, J=170 Hz, 2H, SOCH 2 CH 2 N), 2.96 (m, 2H, CF 2 CH 2 CH 2 SO), 3.84 (m, 2H, CH 2 N), 6.50 (s, br, 1H, NH), 8.19 (s, 1H, CHO).
13 C-NMR Spectrum of Sulfur oxide intermediate #1A could not be obtained due to its insufficient solubility most common organic deuterated solvents.
Sulfur Oxide Intermediate #1B
Sulfur oxide intermediate #1B was N-[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octane-1-sulfonyl)-ethyl]-formamide which was made by oxidation of Amide Intermediate #1C as follows. A solution of sodium tungstate (0.01 equivalents), phenyl phosphonate (0.01 equivalents), and trioctylmethyl ammonium bisulfate (0.01 equivalents) in hydrogen peroxide (35 w/% in water, 2.2 equivalents) was prepared. This solution was slowly added to a solution of one equivalent of Amide Intermediate #1C in ethanol at 0° C. The reaction mixture was allowed to warm to ambient temperature and then heated to 60° C. while being stirred. The progress of the reaction was monitored via Gas Chromatography. Upon complete conversion any excess peroxide was destroyed by adding a solution of sodium sulfite (negative peroxide test). The ethanol was removed under reduced pressure. The residue was washed with water and dried in vacuum. Sulfur oxide intermediate #1B was obtained quantitatively as a colorless solid. Mp 108° C. NMR of Sulfur oxide intermediate #1B was obtained as follows.
1 H-NMR (CDCl 3 ): 2.62 (m, 2H, CF 2 CH 2 ), 3.28 (m, br, 4H, CH 2 SO 2 CH 2 ), 3.83 (m, br, 2H, CH 2 N), 6.25 (s, br, 1H, NH), 8.19 (s, 1H, CHO).
13 C-NMR (CDCl 3 ): 22.3 (s, CF 2 CH 2 ), 33.3 (s, CH 2 N), 43.4 (s, SO 2 CH 2 ), 51.6 (s, CH 2 SO 2 ), 161.7 (s, CHO).
Example 5
Fluorinated Amine #2 was (3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octane-1-sulfinyl)-ethylamine which was made by acid catalyzed deacylation of Sulfur oxide intermediate #1A. After acid deacylation, the crude Fluorinated Amine #2 was filtered, washed with water, and dried. The drying step is important because Fluorinated Amine #2 forms adducts with both polar protic and non-protic solvents, respectively. Ethanol was removed from the filtrate under reduced pressure and the residue was washed with water and dried in vacuum. Fluorinated Amine #2 was obtained quantitatively as a colorless solid. Mp>250° C. NMR of Fluorinated Amine #2 was obtained as follows. NMR analysis was performed on crystals obtained from dimethoxyethane (DME) with the following results.
1 H-NMR (DMSO-d 6 ): 2.59 (m, 2H, CF 2 CH 2 ), 2.80 (m, 2H, CH 2 N), 2.88 (m, 2H, SOCH 2 ), 2.98 (m, 2H, CH 2 SO).
Example 6
Fluorinated Amine #3 was 2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octane-1-sulfonyl)-ethylamine which was made by acid catalyzed deacylation of Sulfur oxide intermediate #1B as follows. Example 5 was duplicated except Sulfur oxide intermediate #1B was used instead of Sulfur oxide intermediate #1A. Fluorinated Amine #3 was obtained quantitatively as a colorless solid, mp>250° C. NMR (in CDCl 3 ) and IR analysis was performed on crystals obtained from dimethoxyethane (DME) with the following results.
1 H-NMR (CDCl 3 ): 1.76 (br, 2H, NH 2 ), 2.68 (m, 2H, CF 2 CH 2 ), 3.14 (m, 2H, CH 2 N), 3.28 (m, 2H, SO 2 CH 2 ), 3.39 (m, 2H, CH 2 SO 2 ), 3.63 (m, 4H, OCH 3 ), 3.75 (m, 4H, OCH 2 ).
1 H-NMR (DMSO-d 6 ): 2.71 (m, 2H, CF 2 CH 2 ), 2.97 (m, 2H, CH 2 N), 3.27 (m, 2H, SO 2 CH 2 ), 3.52 (m, 2H, CH 2 SO 2 ).
13 C-NMR (CDCl 3 ): 24.5 (s, CF 2 CH 2 ), 36.2 (m, CH 2 SO 2 ), 43.1 (s, CH 2 N), 46.6 (s, SO 2 CH 2 ), 56.8, 61.9, 71.3, 72.5 (s, DME).
IR Spectrum: 1070 cm−1 (sym. SO2).
Amide Intermediate #2
Amide Intermediate #2 was N-[2-(3,3,4,4-tetrafluoro-4-heptafluoropropyloxy-butylsulfanyl)-ethyl]-formamide was made using amide intermediate synthesis wherein Thiol #2 was the chosen thiol and N-vinylformamide was the chosen N-vinylamide. All volatiles were removed under reduced pressure to furnish the desired crude amide quantitatively with a purity of 97% as an off-white solid. Mp>250° C.
1 H-NMR (CDCl 3 ): 2.38 (m, 2H, CF 2 CH 2 ), 2.77 (m, 4H, CH 2 SCH 2 ), 3.53 (m, 2H, CH 2 N), 6.88 (s, br, 1H, NH), 8.20 s, 1H, CHO).
Example 7
Fluorinated Amine #4 was 2-(3,3,4,4-tetrafluoro-4-heptafluoropropyloxy-butylsulfanyl)-ethylamine which was made by acid catalyzed deacylation of Amide Intermediate #2. NMR analysis was performed on crystals obtained from dimethoxyethane (DME) with the following results.
1 H-NMR (CDCl 3 ): 1.92 (br, 2H, NH 2 ), 2.32 (m, 2H, CF 2 CH 2 ), 2.65 (t, 2H, SCH 2 ), 2.73 (m, 2H, CH 2 S), 2.92 (t, 2H, CH 2 N).
Amide Intermediate #3
Amide Intermediate #3 was N-[2-(3,3,5,5,6,6,7,7,8,8,8-udecafluoro-octylsulfanyl)-ethyl]-formamide which was made using amide intermediate synthesis wherein Thiol #3 was the chosen thiol and N-vinylformamide was the chosen N-vinylamide. All volatiles were removed under reduced pressure to furnish Amide Intermediate #3 quantitatively with a purity of 97% as an off-white solid. Mp>250° C. NMR of Amide Intermediate #3 was obtained as follows.
1 H-NMR (CDCl 3 ): 2.33 (m, 2H, CF 2 CH 2 ), 2.73 (m, 6H, CH 2 SCH 2 and CF 2 CH 2 CF 2 ), 3.54 (m, 2H, CH 2 N), 6.16 (s, br, 1H, NH), 8.19 (s, 1H, CHO).
Example 8
Fluorinated Amine Salt #1 was 2-(3,3,5,5,6,6,7,7,8,8,8-undecafluoro-octylsulfanyl)-ethyl-ammonium chloride which was made by the deacylation of Amide Intermediate #3 as follows. Concentrated hydrogen chloride solution (37.5 w/% in water, five to six-fold molar excess) was added to a solution of one equivalent of Amide Intermediate #3 in ethanol at 0° C. The reaction mixture was allowed to warm to ambient temperature while being stirred. After the initial foam formation ceased the reaction mixture was stirred at 70° C. for 5 hours. The progress of the reaction was monitored via Gas Chromatography. The Fluorinated Amine Salt #1 was isolated in quantitative yield by stripping all volatiles under reduced pressure.
1 H-NMR (MeOH-d4): 2.39 (m, 2H, CF 2 CH 2 ), 2.81 (m, 4H, CH 2 S), 2.90 (m, 2H, SCH 2 ), 3.05 (m, 2H, and CF 2 CH 2 CF 2 ), 3.19 (m, 2H, CH 2 N).
Example 9
According to DE10108543(C1), Fluorinated Isocyanate #1 was 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluoro-8-(2-isocyanato-ethylsulfanyl)-octane which was made as follows. A solution of one equivalent of Fluorinated Amine #1 (0.1 mol) and one equivalent of triethyl amine (0.1 mol) in dry toluene (350 mL) is cooled to 0° C. (ice bath). Ethyl chloroformate (0.11 mol) is added dropwise within 20 min. The mixture, while stirring, was allowed to warm to room temperature. A second equivalent of triethyl amine (0.1 mol) is added followed by the dropwise addition of methyl trichlorosilane (0.12 mol) at 30-40° C. (addition time about 20-30 min). The mixture was then heated to 100° C. for 1 hour. After the mixture had cooled to ambient temperature the precipitated ammonium salts were filtered off. Under steady N 2 flow, both toluene and generated ethoxy methyl dichlorosilane were distilled off at 200 mm Hg. The residue was dried in vacuum to furnish Fluorinated Isocyanate #1 in 95% yield as a light red-brown liquid. NMR analysis yielded the following results.
1 H-NMR (CDCl 3 ): 2.34 (m, 2H, CF 2 CH 2 ), 2.73 (m, 4H, CH 2 SCH 2 ), 3.45 (m, 2H, CH 2 N).
13 C-NMR (CDCl 3 ): 23.1 (s, CH 2 S), 32.1 (m, CF 2 CH 2 ), 35.8 (s, SCH 2 CH 2 N), 40.5 (s, CH 2 N), 106-121 (m, CF 2 ), 123.8 (s, NCO).
Example 10
According to J. Org. Chem. 1956, 21, 404-405, Fluorinated Isothiocyanate #1 was 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluoro-8-(2-isothiocyanato-ethylsulfanyl)-octane which was made as follows. A solution of one equivalent of Fluorinated Amine #1 (0.1 mol) and two equivalents of triethyl amine (0.2 mol) in dry methylene chloride (200 mL) was cooled to 0° C. (ice bath). Carbon disulfide (1.3 equivalents) was added drop-wise within 20 min. The mixture was allowed to warm to ambient temperature while stirring was continued for one hour. The reaction mixture was stirred for additional 8 hours at ambient temperature. Toluene (200 mL) was added and precipitated solids were filtered of (Buechner). The solvents of the filtrate were removed in vacuum to furnish the desired product in sufficient purity for further derivatization in 97% yield. NMR analysis yielded the following results.
1 H-NMR (CDCl 3 ): 2.35 (m, 2H, CF 2 CH 2 ), 2.78 (m, 4H, CH 2 SCH 2 ), 3.68 (m, 2H, CH 2 N).
13 C-NMR (CDCl 3 ): 23.1 (s, CH 2 S), 32.1 (m, CF 2 CH 2 ), 32.6 (s, SCH 2 CH 2 N), 45.0 (s, CH 2 N), 106-121 (m, CF 2 ), 133.4 (s, NCO).
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The present invention provides a method of making sulfur containing fluoroalkyl amines which overcomes the problems of previously known methods. Sulfur containing fluoroalkyl amines are useful as intermediates for compounds which are in turn useful for imparting water and oil repellency to textiles. Sulfur containing fluoroalkyl amines used in this manner may be found in Example 8 of Rondestvedt et al. (U.S. Pat. No. 3,655,732) wherein they are made by reacting an iodo-fluoroalkyl with an aminoalkyl thiol. Specifically, Rondestvedt et al. teaches reacting CF 3 (CF 2 ) 5 (CH 2 ) 2 I (an iodo-fluoroalkyl) with HS—CH 2 CH 2 —NH 2 (an aminoalkyl thiol) to make CF 3 (CF 2 ) 5 (CH 2 ) 2 —S—CH 2 CH 2 —NH 2 (a sulfur containing fluoroalkyl amine). Unlike previously known methods, the method of the present invention can achieve higher yields of sulfur containing fluoroalkyl amines without resorting to costly solvents. Furthermore, unlike previously known methods, the method of the present invention can produce oxidized forms of sulfur containing fluoroalkyl amines wherein the sulfur atom thereof is oxidized.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to the art of appliances, and more particularly, to an appliance having a display system adapted to show a leveling condition of the appliance.
2. Discussion of the Prior Art
Various types of appliances are commonly placed in a wide range of environments, both in the business and domestic markets. For proper operation, many appliances must be supported in a level condition. However, when such appliances are installed, they are often supported on floors or foundations which are not perfectly flat or level. Nonetheless, it is critical that the appliance be mounted in a level and stable condition in order to function properly. This requirement can extend to a wide range of commonly known appliances, including clothes washing machines, clothes dryers, dishwashers and refrigerators.
For instance, the leveling and stabilizing of a washing machine are important in connection with the overall operation of the machine. A washing machine which is not level and stable will rock during operation and be more likely affected by unbalanced loads within the washing machine, particularly during an extraction cycle. Indeed, unlevel washing machines have been known to rock back and forth to the point that they “walk” across a laundry room floor. Such motion is intolerable and numerous proposed solutions to this problem have heretofore been presented.
Typically, appliances are provided with adjustable support feet which can be selectively extended or retracted. During installation, a technician can adjust each of the feet individually until the machine is level. Most often, such adjustments are made either by delivery personnel through merely visual inspection or, alternatively, the use of a carpenter's level. Obviously, the visual approach is not very accurate and requiring the installer to carry additional tools, such as a level, is also not desirable. In addition, even with the use of a level, various leg adjustment iterations are generally necessary, in combination with periodic shifting of the level, to achieve a final level condition.
Based on the above, there exists a need in the art of appliances for a system which can be used to readily convey a leveling condition of the appliance to an installer or user thereof. Specifically, there exists a need for a leveling system which is integrated into the appliance and incorporates a display that visually represents the level condition of the appliance.
SUMMARY OF THE INVENTION
An appliance constructed in accordance with the present invention incorporates a display system for visually representing a leveling condition of the appliance. Preferably, the leveling display system incorporates a two axis accelerometer used to determine if the machine is level and an LCD display which shows the information obtained from the accelerometer. In accordance with a preferred embodiment of the invention, the appliance includes a liquid crystal display (LCD) having a bubble icon represented on the LCD in relation to a number of concentric circles to convey the leveling condition of the appliance in both front to back and side to side directions. In practice, signals from the two axis accelerometer is sent to a controller of the appliance, whereupon the controller interprets the signals and appropriately alters the display.
In use, when installing an appliance, the installer enters a special control mode through the display such that the level icon arrangement is visually illustrated. Based on the graphic representation provided, the installer can readily determine which of various leveling legs of the appliance need to be adjusted. The installer can continue to adjust one or more of the legs, while getting constant feedback through the display, until a desired leveling condition is reached. After initial appliance installation, information from the same accelerometer can be advantageously used to convey whenever a subsequent unlevel condition, as well as other appliance conditions, arises. For instance, in the case of a clothes washing machine, an actual or incipient unbalance, a starving drain pump, or an excessive vibration condition can be sensed, with signals being relayed to the controller for suitably altering the operation of the machine and/or providing a visual warning to the user of the appliance.
Additional objects, features and advantages of the invention will become more readily apparent from the following detailed description of preferred embodiments of the invention, when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut away, perspective view of a washing machine incorporating a leveling display system constructed in accordance with the present invention;
FIG. 2 is an exploded view of the various internal components of the washing machine of FIG. 1;
FIG. 3 is a cross-sectional view of the internal components of the washing machine of FIG. 2 in an assembled state; and
FIG. 4 is an enlarged view of the leveling display of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of describing the invention, reference will be made to the application of the invention in a laundry appliance. However, as will become readily apparent below, the invention is applicable to a wide range of appliances. Therefore, with initial reference to FIG. 1, an automatic horizontal axis washing machine incorporating the display system of the present invention is generally indicated at 2 . In a manner known in the art, washing machine 2 is adapted to be front loaded with articles of clothing to be laundered through a tumble-type washing operation. As shown, automatic washing machine 2 incorporates an outer cabinet shell 5 provided with a front door 8 adapted to extend across an access opening 10 . Front door 8 can be selectively pivoted to provide access to an inner tub or spinner 12 that constitutes a washing basket within which the articles of clothing are laundered.
As is known in the art, inner tub 12 is formed with a plurality of holes 15 and multiple, radially inwardly projecting fins or blades 19 are fixedly secured to inner tub 12 . Inner tub 12 is mounted for rotation within an outer tub 25 , which is supported through a suspension mechanism (not shown) within cabinet shell 5 . Inner tub 12 is mounted within cabinet shell 5 for rotation about a generally horizontal axis. Actually, the rotational axis is angled slightly downwardly and rearwardly as generally represented in FIG. 3 . Although not shown, a motor, preferably constituted by a variable speed, reversible electric motor, is mounted within cabinet shell 5 and adapted to drive inner tub 12 . More specifically, inner tub 12 is rotated during both wash and rinse cycles such that articles of clothing placed therein actually tumble through either water, water/detergent or another washing fluid supplied within inner tub 12 . Given that inner tub 12 is provided with at least the plurality of holes 15 , the water or water/detergent can flow between the inner and outer tubs 12 and 25 . A pumping system (not shown) is provided to control the level of washing fluid within machine 2 , with one pump 30 , shown schematically in FIG. 3, particularly controlling the timed draining of the fluid from the outer tub 25 .
The general manner in which the automatic washing machine 2 of FIG. 1 operates is well known in the art and is not considered an aspect of the present invention. Therefore, a full description of its operation will not be described here. However, for the sake of completeness, automatic washing machine 2 is also shown to include an upper cover 42 that provides access to an area for adding detergent, softeners and the like. In addition, an upper control panel 45 , including an LCD display screen 46 , is provided for manually establishing a desired washing operation in a manner known in the art.
As best seen in FIGS. 2 and 3, in order to allow inner tub 12 to freely rotate within outer tub 25 during a given washing operation, inner tub 12 is spaced concentrically within outer tub 25 . This spacing establishes an annular gap 56 between the inner and outer tubs 12 and 25 . As will be discussed fully below, an axial gap is also created at the open frontal portions of inner and outer tubs 12 and 25 . During operation of washing machine 2 , the washing fluid can flow through gap 56 from inner tub 12 into outer tub 25 . In addition, small objects can also flow into the outer tub 25 through the axial gap. Unfortunately, it has been found in the past that some objects flowing through the axial gap can end up clogging or otherwise disrupting the normal operation of the pumping system, thereby leading to the need for machine repairs. In order to remedy this situation, it has been heretofore proposed to incorporate a flexible sealing device, generally indicated at 60 in FIGS. 1 and 3, which functions to bridge this gap between inner and outer tubs 12 and 25 to prevent such objects from flowing into the outer tub 25 . Further provided as part of washing machine 2 , in a manner known in the art, is a sealing boot 62 which extends generally between outer tub 25 and a frontal panel portion (not separately labeled) of cabinet shell 5 .
Reference now will be made to FIGS. 2 and 3 in describing the preferred mounting of inner tub 12 within outer tub 25 and the arrangement of both sealing device 60 and sealing boot 62 as the tumble cycle feature of the present invention is related to the presence of one or more of these structural elements. Inner tub 12 has an annular side wall 61 and an open front rim 71 about which is secured a balance ring 75 . In the preferred embodiment, balance ring 75 is injection molded from plastic, such as polypropylene, with the balance ring 75 being preferably mechanically attached to rim 71 . Inner tub 12 also includes a rear wall 77 to which is fixedly secured a spinner support 79 . More specifically, spinner support 79 includes a plurality of radially extending arms 81 - 83 which are fixedly secured to rear wall 77 by means of screws 84 or the like. Spinner support 79 has associated therewith a driveshaft 85 . Placed upon driveshaft 85 is an annular lip seal 88 . Next, a first bearing unit 91 is press-fit onto driveshaft 85 . Thereafter a bearing spacer 93 is inserted upon driveshaft 85 .
The mounting of inner tub 12 within outer tub 25 includes initially placing the assembly of inner tub 12 , balance ring 75 , spinner support 79 , lip seal 88 , first bearing unit 91 and bearing spacer 93 within outer tub 25 with driveshaft 85 projecting through a central sleeve 96 formed at the rear of outer tub 25 . More specifically, a metal journal member 99 is arranged within central sleeve 96 , with central sleeve 96 being preferably molded about journal member 99 . Therefore, driveshaft 85 projects through journal member 99 and actually includes first, second and third diametric portions 102 - 104 . In a similar manner, journal member 99 includes various diametric portions which define first, second and third shoulders 107 - 109 . Journal member 99 also includes an outer recess 111 into which the plastic material used to form outer tub 25 flows to aid in integrally connecting journal member 99 with outer tub 25 .
As best shown in FIG. 3, the positioning of driveshaft 85 in journal member 99 causes each of annular lip seal 88 , first bearing 91 and bearing spacer 93 to be received within journal member 99 . More specifically, annular lip seal 88 will be arranged between first diametric portion 102 of driveshaft 85 and journal member 99 . First bearing unit 91 will be axially captured between the juncture of first and second diametric portions 102 and 103 , as well as first shoulder 107 . Bearing spacer 93 becomes axially positioned between first bearing unit 91 and second shoulder 108 of journal member 99 . Thereafter, a second bearing unit 114 is placed about driveshaft 85 and inserted into journal member 99 , preferably in a press-fit manner, with second bearing unit 114 being seated upon third shoulder 109 . At this point, a hub 117 of a spinner pulley 118 is fixedly secured to a terminal end of driveshaft 85 and axially retains second bearing unit 114 in position. Spinner pulley 118 includes an outer peripheral surface 120 which is adapted to be connected to a belt (not shown) driven in a controlled fashion by the reversible motor mentioned above in order to rotate inner tub 12 during operation of washing machine 2 . In order to provide lubrication to lip seal 88 , central sleeve 96 is formed with a bore 123 that is aligned with a passageway 124 formed in journal member 99 .
Outer tub 25 has associated therewith a tub cover 128 . More specifically, once inner tub 12 is properly mounted within outer tub 25 , tub cover 128 is fixedly secured about the open frontal zone of outer tub 25 . Although the materials for the components discussed above may vary without departing from the spirit of the invention, outer tub 25 , balance ring 75 and tub cover 128 are preferably molded from plastic, while inner tub 12 is preferably formed of stainless steel. Again, these materials can vary without departing from the spirit of the invention. For example, inner tub 12 could also be molded of plastic.
Outer tub 25 is best shown in FIG. 2 to include a plurality of balance weight mounting gusset platforms 132 and 133 , a rear mounting boss 136 and a front mounting support 137 . It should be realized that commensurate structure is provided on an opposing side portion of outer tub 25 . In any event, balance weight mounting platforms 132 and 133 , mounting boss 136 , mounting support 137 and further mounting boss 140 are utilized in mounting outer tub 25 within cabinet shell 5 in a suspended fashion. Again, the specific manner in which outer tub 25 is mounted within cabinet shell 5 is not considered part of the present invention, so it will not be described further herein. Outer tub 25 is also provided with a fluid inlet port 141 through which washing fluid, i.e., either water, water/detergent or the like, can be delivered into outer tub 25 and, subsequently, into inner tub 12 in the manner discussed above. Furthermore, outer tub 25 is formed with a drain port 144 which is adapted to be connected to the pump 26 for draining the washing fluid from within inner and outer tubs 12 and 25 during certain cycles of a washing operation.
As best illustrated in FIG. 3, inner tub 12 is entirely spaced from outer tub 25 for free rotation therein. This spaced relationship also exists at the front ends of inner and outer tubs 12 and 25 such that an annular gap 146 is defined between an open frontal zone 147 of outer tub 25 and an open frontal portion 149 associated with balance ring 75 . It is through a lower section of gap 146 that washing fluid can also flow from within inner tub 12 to outer tub 25 . With this fluid flow, other items including buttons, hair pins and the like inadvertently placed in inner tub 12 with the clothes to be washed, can get into outer tub 25 . Typically, the pump 26 associated with drain port 144 is capable of managing certain objects without any problem. However, depending upon the size and number of the objects, the pump 26 may not be able to handle the objects, whereby the pump 26 will clog or at least the normal operation thereof will be disrupted.
Because of this problem, the flexible sealing device 60 is mounted so as to bridge gap 146 between inner and outer tubs 12 and 25 and, specifically, between balance ring 75 and tub cover 128 . Gap 146 is required because of deflections between inner tub 12 and outer tub 25 during operation of washing machine 2 . Sealing device 60 bridges gap 146 to prevent small items from passing through, but sealing device 60 is flexible so as to accommodate changes in the size of gap 146 resulting from deflections during operation. Sealing device 60 includes a first seal portion 151 that is fixed or otherwise secured to a rear or inner surface 152 of tub cover 128 and a second, flexible seal portion 155 , such as brush bristles or a plastic film, which projects axially across gap 146 and is placed in close proximity and most preferably in sliding contact with a front or outer surface 156 of balance ring 75 . As is also known in the art, sealing boot 62 includes an inner annular end 162 which is fixed sealed to tub cover 128 , an outer annular end 164 which is fixed to the front cabinet panel (not separately labeled) of cabinet shell 5 and a central, flexible portion 166 . As perhaps best shown in FIG. 3, flexible portion 166 actually defines a lower trough 168 .
Until this point, the basic structure of washing machine 2 as described above is known in the art and has been described both for the sake of completeness and to establish the need and advantages of the leveling display system of the present invention which will be detailed below. The present leveling display system is shown as a modification to washing machine 2 having the LCD display 46 . LCD display 46 can be used to operate washing machine 2 in accordance with the disclosure in copending U.S. patent application Ser. No. 09/741,067 filed Dec. 21, 2000 which is hereby incorporated by reference. In addition to the conventional parts of washing machine 2 as described above, the leveling display system includes an accelerometer 170 which may be mounted essentially anywhere within the washing machine 2 .
As best represented in FIG. 4, display 46 is able to show a pattern, preferably in the form of a target icon, such as a bullseye, enabling a technician, installer or other user of washing machine 2 to discern whether or not the machine 2 is level, particularly when being installed. In the most preferred form of the invention, the pattern is represented by a series of concentric rings 172 - 175 as shown in FIG. 4, along with a moving dot 176 which essentially represents a “bubble” analogous to that found in a conventional liquid-type carpenter's level. Signals from accelerometer 170 are directed to a central processing unit (CPU) 177 incorporating specific circuits. More specifically, CPU 177 includes a level detection circuit 178 and an unbalance/pump starvation detection circuit 179 , along with several controls such as a display controller 181 , a tub drive controller 182 , cycle controls 184 and a control for pump 30 .
As shown in FIG. 3, accelerometer 170 is preferably mounted to a rear wall of outer tub 25 of washing machine 2 . Accelerometer 170 is connected through a wire (not shown) to CPU 177 . In general, accelerometer 170 is a two axis accelerometer which can measure the tilting of machine 2 , either around a horizontal axis about which the tub 12 rotates or, alternatively, about an axis which is 90° relative thereto. Such an arrangement enables accelerometer 170 to determine whether washing machine 2 is tilted too far to the left or right, or front to back, as typically viewed from the front of machine 2 as seen in FIG. 1 .
Central processing unit 177 receives signals from accelerometer 170 and interprets them in several ways. Primarily CPU 177 uses a level detection circuit 178 in order to determine the amount of tilting in the machine 2 in the various directions mentioned above. In a preferred embodiment, this information is interpreted and sent to display controller 181 so that display 46 shows the numerous concentric circles 172 - 175 , along with dot 176 which may move relative to circles 172 - 175 to indicate how far machine 2 is off level. Ideally, when dot 176 aligns with the center of concentric circles 172 - 175 , machine 2 is perfectly level.
In operation, a technician, installer or other user of washing machine 2 will select an icon initially represented in display 46 in order to have CPU 177 present the concentric circles 172 - 175 and bubble 176 , as opposed to standard control options which are normally depicted. Thereafter, feet 190 located at the bottom of cabinet shell 5 of washing machine 2 , as shown in FIG. 1, are manually adjusted until display 46 indicates that machine 2 is level. Of course, although only two manually adjustable feet 190 , which are threadably attached to cabinet shell 5 , are depicted, it should be clearly understood that a total of four feet 190 , two in the front and two in the rear of cabinet shell 5 , are preferably provided.
It should be noted that accelerometer 170 can be used for numerous other functions within washing machine 2 besides just feeding signals to CPU 177 to be processed through level detection circuit 178 and display controls 181 . Rather, based on signals received by CPU 177 from accelerometer 170 , unbalance/pump starvation detection circuit 179 can determine whether machine 2 is unbalanced or exhibits an excessive vibration. In accordance with the invention, the presence of an unbalance condition is counteracted by reducing the rate at which basket 12 is being driven through tub drive controls 182 and/or altering the preset operating cycles of washing machine 2 through cycle controls 184 . For instance, if an unbalance condition is detected during the extraction phase of washing machine 2 , the rotational speed imparted to basket 12 is preferably, initially reduced. If this alteration does not alleviate the excessive balance condition, the operating cycle of washing machine 2 is then terminated through cycle controls 184 . Alternatively, cycle controls 184 can simply activate a visual or audible alarm so the user can take appropriate action.
Additionally, CPU 180 and, more specifically, unbalance/pump starvation circuit 179 can also detect characteristic electrical signals from accelerometer 170 which indicate when drain pump 30 is starving, for example during water spinout. While unbalance condition noises are typically caused by cabinet hits from rotating basket 12 and other general vibrations, a starving pump causes vibrations from lack of water and the forcing of water back and forth in a drain hose. In accordance with the invention, accelerometer 170 relays to CPU 177 vibration signals indicative of pump noises which are objectionably high and indicative of classic pump starving conditions. Once CPU 177 senses that accelerometer 170 is conveying characteristic signals of pump starvation through circuit 179 , cycle controls 184 are preferably used to turn pump 30 off to avoid the pump starvation condition. Furthermore, when the water level is high enough to hit inner basket 12 and thus cause a characteristic vibration within washing machine 2 , cycle controls 184 function to turn drain pump 30 on again.
Still further, accelerometer 170 , provided for use in leveling washing machine 2 in accordance with the invention, may also be used to find optimum speeds that provide a relatively low amount of vibration in washing machine 2 . A similar method of finding an optimal rotational speed for tub 12 to keep a washing machine vibration at a minimum can be found in U.S. Pat. No. 5,930,855 which is incorporated herein by reference.
Based on the above description, it is readily apparent that the present invention provides a simple and inexpensive leveling display system which provides a convenient and effective manner to level an appliance to enhance the operation thereof. Additionally, the preferred embodiment provides an efficient way to effect further control of an appliance economically using certain parts of the leveling display system. In any event, although described with reference to a preferred embodiment of the invention as incorporated in a washing machine, it should be understood that the invention can also be utilized in various other types of appliances, including clothes dryers, dishwashers and refrigerators, all of which would exhibit enhanced operating performance when level. For example, for proper operation, a refrigeration circuit needs to be properly leveled such that the leveling display system could be advantageously employed in a refrigerator. Corresponding advantages are achieved in clothes dryers and dishwashers as well. In any event, various changes and/or modifications can be made to the invention without departing from the spirit thereof. Finally, it should be realized that other known devices for sensing a leveling condition can be employed in place of accelerometer 170 . Therefore, in general, the invention is only intended to be limited by the scope of the following claims.
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An appliance is provided with a display system for use in connection with leveling the appliance. The system includes an accelerometer used in connection with an electronic controller to sense the degree to which the appliance is not level. Signals from the accelerometer are sent to a CPU which regulates a visual depiction on a display provided on the appliance. Adjustments made to alter the leveling condition of the appliance are also relayed to CPU, thereby updating the display and conveying when the appliance is suitably level. The system components can also be used to regulate other appliance operations.
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CROSS RELATED APPLICATION
[0001] This application is a divisional application claiming the benefits of U.S. Non-provisional patent application Ser. No. 13/747,976 filed Jan. 23, 2013, the entirety of which is incorporated herein by reference; the 13/747,976 application in turn claims the benefit of U.S. Provisional Patent Application No. 61/598,112 filed Feb. 13, 2012, the entirety of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to flashing fluids extracted from pressurized reactor vessels and particularly to flash tanks for flashing black liquor from a pressurized reactor vessel in a pulping or biomass treatment system.
[0003] Flash tanks are generally used to flash a high pressure fluid liquor stream including steam and condensate. A flash tank typically has a high pressure inlet port, an interior chamber, an upper steam or gas discharge port and a lower condensate or liquid discharge port. Flash tanks safely and efficiently reduce pressure in a pressurized fluid stream, allow recovery of heat energy from the stream, and collect chemicals from the stream in condensate.
[0004] Flash tanks may be used to recover chemicals from chemical pulping systems, such as Kraft cooking systems. Flash tanks are also used in other types of cooking systems for chemical and mechanical-chemical pulping systems. To pulp wood chips or other comminuted cellulosic fibrous organic material (collectively referred to herein as “cellulosic material”), the cellulosic material is mixed with liquors, e.g., water and cooking chemicals, and pumped in a pressurized treatment vessel. Sodium hydroxide, sodium sulfite and other alkali chemicals are used to “cook” the cellulosic material such as in a Kraft cooking process. These chemicals degrade lignins and other hemicellulose compounds in the cellulosic material. The Kraft cooking process is typically performed at temperatures in a range of 100 degrees Celsius (100° C.) to 170° C. and at pressures at or substantially greater than atmospheric.
[0005] The cooking (reactor) vessels may be batch or continuous flow vessels. The cooking vessels are generally vertically oriented and may be sufficiently large to process 1,000 tons or more of cellulosic material per day. The material continuously enters and leaves the vessel, and remains in the vessel for several hours. In addition to the cooking vessel, a conventional pulping system may include other reactor vessels (such as vessels operating at or near atmospheric pressure or pressurized above atmospheric pressure) such as for impregnating the cellulosic material with liquors prior to the cooking vessel. In view of the large amount cellulosic material in the impregnation and cooking vessels, a large volume of black liquor is typically extracted from these vessels.
[0006] The black liquor includes the cooking chemicals and organic chemicals or compounds, e.g., hydrolysate, residual alkali, lignin, hemicellulose and other dissolved organic substances, dissolved from the cellulosic materials. The black liquor is flashed in a flash tank to generate steam and condensate. The cooking chemicals and organic compounds are included with the liquid condensate formed when the liquor is flashed. The steam formed from flashing is generally free of the chemicals and organic compounds. The condensate is processed to, for example, recover and recausticize the cooking chemical. The steam may be used as heat energy in the pulping system.
[0007] In conventional flash tanks, the black liquor enters flash tanks through an inlet pipe having a fixed inlet diameter. The inlet is not variable or otherwise controllable to adjust the size of the black liquor flow passage. Changes to the flow passage at the inlet to a conventional flash tank for black liquor have been made by changing the inlet piping to the flash tank. Conventional flash tanks do not have a means for adjusting the flow passage; controlling of the volume or the velocity of the black liquor flow into the flash tank, pressure drop in the flash tank, or regulating the pressure in the conduits containing black liquor connected to the inlets to the flash tanks.
BRIEF DESCRIPTION OF THE INVENTION
[0008] An inlet for a flash tank has been conceived where the flow passage area of the inlet to the flash tank is varied to allow for control of the flow passage area of the inlet to the flash tank without changing of physical or mechanical components of the inlet or flash tank. The flow passage area is adjusted by a pivoting hinged plate in the inlet to the flash tank. This movable, hinged plate may be located at, near or after the junction between piping and the inlet to the flash tank. At this junction, the piping typically transitions from piping having a rectangular cross-section to piping circular in cross-section.
[0009] The movable, hinged plate changes of the cross-sectional area of the inlet to adjust the flow passage area through which hot black liquor flows from fully open to smaller area or from a smaller area to a larger area. This adjustment of the inlet opening size provides a means to control the velocity of the fluid into the tank.
[0010] The movable, hinged plate may be operated by a pneumatic or electro-mechanical actuator. A formable seal may be provided on either the movable hinged plate or the interior of the pipe to prevent leaking of hot black liquor out of the pipe or past the side edges of the plate.
[0011] A flash tank has been conceived including: a closed interior chamber; a gas exhaust port coupled to an upper portion of the chamber; a liquid discharge port coupled to a lower portion of the chamber; an inlet nozzle attached to an inlet port of the chamber, wherein the inlet nozzle includes a flow passage having a throat, and a movable valve plate in the flow passage, wherein the valve plate has a first position which defines a first throat area in the flow passage and a second position which defines a second throat area having a smaller cross-sectional area than the first throat area.
[0012] The valve plate may be a rectangular plate having planar surfaces bounded by edges and the flow passage may have a rectangular cross-section. The rectangular plate may be attached to a hinge attached to a sidewall of the flow passage. The hinge may be attached to an upstream end of the valve plate and creates a pivoting axis for the valve plate.
[0013] The valve plate may have an actuator connected to the valve plate, wherein the actuator moves the valve plate between the first and second positions.
[0014] The valve plate may be moved by an actuator having an extendible shaft connected to the valve plate, wherein the actuator moves the valve plate between the first and second positions.
[0015] A method has been conceived to flash a pressurized liquor comprising: feeding a pressurized liquor to an inlet nozzle of a flash tank; flashing the pressurized liquor as the liquor flows from the inlet nozzle into an interior chamber of the flash tank; exhausting a gas exhaust formed by the flashing through an upper portion of the chamber; discharging a liquid formed by the flashing from a lower portion of the chamber, and adjusting a cross-sectional area of a flow passage in the inlet nozzle by moving a valve plate in the flow passage.
[0016] The step of feeding may include a first feeding step in which the pressurized liquor flows through the flow passage while the valve plate is at a first position which defines a first throat area in the flow passage and a second feeding step in which the pressurized liquor flows through the flow passage while the valve plate is in a second position which defines a second throat area having a smaller cross-sectional area than the first throat area. Additional valve plate positions may also exist where the valve plate in multiple positions along the flow passage define multiple throats having smaller cross-sectional areas than the first throat area.
[0017] The method may include adjusting the cross-sectional area of the flow passage in the inlet nozzle allows for control of the volume of flow of black liquor entering the flash tank. Adjusting of the cross-sectional area of the flow passage inlet nozzle may also allow for control of the flow velocity of the black liquor entering the flash tank. Additionally, adjusting the cross-sectional area of the flow passage in the inlet nozzle allows for a degree of control over the pressure drop in the flash tank. Adjusting the cross-sectional area of the flow passage in the inlet nozzle may also ensure sufficient pressure in the conduits upstream of the inlet nozzle to the flash tank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic diagram of a conventional flash tank receiving black liquor extracted from a pressurized reactor vessel.
[0019] FIG. 2 is cross-sectional view of the flash tank taken along a horizontal line, wherein the inlet nozzle is attached to the tank along a tangent to tank.
[0020] FIG. 3 shows a perspective and partially cut-away view of the inlet nozzle to illustrate the valve plate and the connection of the nozzle to the sidewall of the flash tank.
[0021] FIG. 4 is a cross-sectional schematic view of the inlet nozzle taken along a vertical plane to illustrate the valve plate.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 is a schematic diagram of a pulping system including a flash tank 10 coupled to a vessel 12 , e.g., an impregnation vessel or a cooking vessel. A slurry of cellulosic material 14 and liquor flow to an upper inlet 15 of the vessel 12 . White liquor 16 may be added to the vessel 12 such as through center inlet pipes 18 . Screen assemblies 20 at various elevations in the vessel 12 extract black liquor from the cellulosic material moving down through the vessel 12 . The material is discharged as pulp 22 from the bottom 24 of the vessel.
[0023] The black liquor extracted from the vessel 12 may flow to the flash tank 10 through conduits 26 fluidly coupling the screen assemblies 20 to a respective flash tank 10 . The number of flash tanks 10 and whether one flash tank 10 receives black liquor from multiple screen assemblies 20 are design choices. The number, size and arrangement of flash tanks 10 may also depend on the design choice of whether to have heat exchange equipment in the conduits 26 leading to the flash tanks 10 .
[0024] Black liquor flashes in the flash tank 10 to form steam 28 and condensate 30 . The steam 28 flows out upper outlets 17 of the flash tanks 10 . The condensate 30 flows as a liquid from bottom discharges 19 of the flash tanks 10 .
[0025] FIG. 2 is a cross-sectional view of the flash tank 10 , wherein the cross-section is along a horizontal plane bisecting the inlet piping system to the flash tank 10 . The conduits 26 transporting the black liquor to be flashed may be cylindrical pipes. The inlet nozzle 34 to the flash tank 10 may be rectangular in cross-section. An end outlet 32 of the conduits 26 connects to the inlet nozzle 34 attached to the flash tank 10 . The inlet nozzle 34 may be tangential to a cylindrical portion 38 of the flash tank 10 .
[0026] The flash tank 10 need not be cylindrical and the inlet nozzle 34 need not be tangential to the flash tank 10 . The flash tank 10 may have planar sections in its sidewall. Other suitable configurations of the inlet nozzle 34 may be oriented vertically and attached to the top of the flash tank 10 or to the side of the flash tank 10 without being tangential to the sidewall of the flash tank 10 .
[0027] The flow passage 40 through inlet nozzle 34 may be rectangular, e.g., square, in cross-section. The rectangular cross section allows a valve plate 42 in the flow passage 40 to move, e.g., pivot, within the flow passage 40 . The valve plate 42 regulates the velocity of the flow stream of black liquor to the flash tank 10 .
[0028] A transition section 44 at the upstream end of the inlet nozzle 34 may convert a round inlet to a rectangular cross section of the remainder of the flow passage 40 through the inlet nozzle 34 . The inlet of the transition section 44 connects to the end of the conduit 26 . The outlet of the transition section 44 connects to the inlet nozzle 34 . The transition section 44 may include a flange coupling 31 to attach to an end outlet 32 of the conduit 26 .
[0029] FIG. 3 illustrates an exemplary valve plate 42 in the inlet nozzle 34 . The inlet nozzle 34 extends tangentially to the cylindrical portion 38 of the flash tank 10 . The valve plate 42 may be attached to a hinge 46 fixed to a sidewall 48 of the flow passage 40 through the inlet nozzle 34 . An upstream end 50 end of the valve plate 42 is fixed to the hinge 46 and may be adjacent the sidewall 48 .
[0030] Pressurized black liquor flows through the flow passage 40 and, specifically, between the valve plate 42 and an opposite sidewall 52 of the inlet nozzle 34 . The valve plate 42 may extend downstream such that the downstream edge 54 of the valve plate 42 is proximate to an opening 56 in the side of the cylindrical portion 38 of the flash tank 10 .
[0031] The valve plate 42 pivots, see arrow 58 , about the vertical axis of the hinge 46 . The range of angles through which the valve plate 42 pivots is a design parameter to be selected during the design of the inlet nozzle 34 . The range of angles may swing the valve plate 42 from being adjacent to the sidewall 48 (a zero angle position) to a maximum angle position where the downstream edge 54 abuts the end of the opposite sidewall 52 .
[0032] The downstream edge 54 of the valve plate 42 will form an edge of the throat area (T in FIGS. 2 and 4 ) of the flow passage 40 . The throat area T is the narrowest cross-sectional area of the flow passage 40 . The throat area T is directly related to the capacity, quantity of black liquor the flow passage 40 is capable of passing to the flash tank 10 . The throat area T of the flow passage 40 is widest and has a maximum capacity when the angle of the valve plate 42 is zero and the valve plate 42 is adjacent the sidewall 48 . The throat area T of the flow passage 40 is narrowest and has a minimum capacity, which may be a zero flow rate, when the valve plate 42 is at a maximum angle the downstream edge 54 nearest the opposite sidewall 52 of the flash tank 10 .
[0033] The downstream edge 54 of the valve plate 42 may have a replaceable or hardened strip 60 , e.g., soft metal such as copper or a plastic material capable of withstanding the abrasive conditions such as those from the black liquor, which may be available to act as a seal between the downstream edge 54 of the valve plate 42 and the opposite sidewall 52 or interior wall of the flash tank 10 . A similar strip 60 may be along the upper and lower side edges of the valve plate 42 .
[0034] FIG. 4 is a cross-sectional schematic diagram of the inlet nozzle 34 taken along a vertical plane and showing a side of the flash tank 10 . FIG. 4 shows a view looking directly into the inlet nozzle 34 in a downstream direction of the flow passage 40 . The rectangular cross-sectional shape of the flow passage 40 is evident as is the oval or circular shape of the opening 56 to the flash tank 10 . The valve plate 42 is shown extending partially across the flow passage 40 and forming a rectangular throat area (T). The valve plate also extends across and blocks a portion of the opening 56 to the flash tank 10 .
[0035] The area of the flow passage 40 and portion of the opening 56 blocked or closed off by the valve plate 42 depends on the position of the valve plate 42 and particularly on the position of the downstream edge 54 (see FIG. 3 ) of the valve plate 42 . The valve plate 42 may extend completely across the flow passage 40 and cover the entire flow passage 40 , from top to bottom and side to side. On the other hand, the valve plate 42 may be positioned to be parallel and adjacent the sidewall 48 and thereby open the flow passage 40 and opening 56 .
[0036] The motion of the movable, hinged valve plate 42 is controlled by a pneumatic or electro-mechanical actuator 62 , such as a pneumatic piston pump. The actuator 62 may have a cylindrical body 64 attached to the side of the flash tank 10 and a reciprocating shaft 66 driven by a piston in the cylindrical body 64 . A distal end of the shaft 66 is pivotable and is attached to the backside of the valve plate 42 . The actuator 62 may extend and retract the shaft 66 to move the valve plate 42 to open the throat area T or close the throat area T of the flow passage 40 . The shaft 66 extends through a port 67 in the sidewall 48 of the inlet nozzle 34 . The port 67 may include a seal to prevent leakage of black liquor.
[0037] A controller 68 , e.g., a computer or manual adjustment, determines the extension of the shaft 66 and the position of the valve plate 42 . The controller 68 may extend the shaft 66 to set the position of the valve plate 42 and achieve a desired throat area T for the flow passage 40 . The controller 68 may be adjusted manually to change or adjust the position of the valve plate 42 . Alternatively, the controller 68 may adjust the position of the valve plate 42 by computer, manual adjustment or other suitable means based on, for example, comparison between a desired pressure in the flow passage 40 and a sensed pressure in the flow passage 40 .
[0038] Hot black liquor extracted from the screens 20 of a vessel 12 flows through the inlet nozzle 34 and enters the flash tank 10 . The throat area T of the inlet nozzle 34 determines volume of flow or flow velocity using backpressure in the flow passage 40 which restricts the flow of black liquor entering the flash tank 10 . Because the throat area T is determined by the position of the valve plate 42 , the controller 68 can move the valve plate 42 to adjust the throat area T and consequently the velocity or volume of flow through the flow passage 40 .
[0039] Controlling the volume of flow or flow velocity in the inlet nozzle 34 allows for the velocity and volume of black liquor entering the flash tank 10 to be regulated, provides a degree of control over the pressure drop in the flash tank 10 and ensures a sufficient pressure in the conduits 26 upstream of the inlet nozzle 34 .
[0040] As the black liquor enters the flash tank 10 , the liquor flashes to produce steam 28 and condensate 30 . The steam 28 may be used as heat energy in the vessel 12 , in an impregnation vessel (not shown), in a chip feed bin (not shown), in a chip steaming vessel (not shown), in a tank holding fresh cooking liquor, e.g., white liquor, or other locations in the mill where steam is needed. The condensate 30 may flow to additional flash tanks 10 or other chemical recovery equipment (not shown), e.g., a recovery boiler, an evaporation system or other chemical recovery system.
[0041] The orientation of the valve plate 42 in the inlet nozzle 34 is a design choice. The hinge 66 for the valve plate 42 may be attached to either sidewall 48 or the top or bottom walls of the flash tank 10 .
[0042] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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A flash tank including: a closed interior chamber; a gas exhaust port coupled to an upper portion of the chamber; a liquid discharge port coupled to a lower portion of the chamber; an inlet nozzle attached to an inlet port of the chamber, wherein the inlet nozzle includes a flow passage, and a movable valve plate in the flow passage, wherein the valve plate has a first position which defines a first throat in the flow passage and a second position which defines a second throat having a smaller cross-sectional area than the first throat.
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BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
This invention is directed to a method and equipment for removing and throwing away snow from a road. The method is to scrape the snow up from the road, lead it to a wind channel and to blow air along the wind channel in a direction away from the scraper and away from the road.
The snow remover includes an air blower and air channel from its pressure side to a hole or holes in the scraper blade or an air channel along the scraper on its rear and leading to conveying holes for the snow into that air channel, or an air channel along the scraper at its front, formed by the scraper and extending blades and flaps.
The snow removal equipment either moves the snow to one side, alternately to both sides, or to both sides at the same time. The scraper blade can be fixed, straight or plow formed, can be raised and lowered and can be inclinable. The blower is either powered by its own motor or powered by the motor of the associated vehicle, which can be a truck, a tractor, a heavy-duty universal tractor, a car, a jeep or a road planer or special snow removal equipment. Also to be considered are hand operated equipment, pushed forward similar to a lawn mower.
2. DESCRIPTION OF THE PRIOR ART
The most common snow removal equipment is a scraper, mounted on a heavy truck. The scraper lifts the snow up from the road. It is inclined and therefore at the same time snow is progressively pushed to one side, where it builds up as a ridge or a snowbank all along the road. This ridge causes much trouble. It is hindering to all vehicle traffic and encloses or blocks vehicles at the roadside whereafter they must be shoveled free. In a wind the snow is drifting over the ridge and down to the road and in such cases that snow must subsequently be removed along with the snow in the ridge too.
Scrapers are very effective and in an even snow they can be forced forward at a full speed of say 80 km/hr, if the road and conditions allow. Then the snow is thrown out over the roadside and does not form a ridge. Such conditions are very rare. Bad weather conditions, snowfall, unclear view, darkness, bends in the road, traffic, vehicles on the roadside, safety fences and other hindrances all limit the speed and the resultant loss of inertia leads to the unavoidable snow ridge.
Another common snow removal equipment is the snow blower. It does not include a scraper, but uses a spiral mechanism, which moves the snow to the middle point where the snow enters a centrifugal blower, which directly pumps it through and blows it upwards in a direction over the roadside. The snow blower is mainly used to remove snow ridges left by scrapers. It is ineffective and moves slowly. The typical speed is 1 to 3 km/hr and it effects 10 to 18 tons/min.
The third snow removal equipment is the snowplow, which is a plow-formed scraper, moving the snow to both sides and is mainly used on snowbanks, where the scraper is unable to get through. The plow is a much heavier apparatus than the scraper and made for greater impact and needs a high powered, heavy vehicle behind itself. With a sufficient speed (80 km/hr) the plow can throw the snow over the roadside and then no snow ridge is formed.
Thus various prior art snow removal equipment serve their own purpose in snow-removal. The plow works the snowbanks but is unnecessarily big and heavy for other situations. The snow blower is usable on ridges and snowbanks, but is slow and ineffective in other cases. The snow scrapers are most suitable for even snow, but they only remove sufficiently at full speed, where there are no hindrances, otherwise they leave ridges.
Bulldozers are not directly snow-removal equipment, but still are used for pushing away ridges and snowbanks. They move slowly but can move everything. Road planers can push snow ridges a little to one side and widen the free road but are otherwise only slow-moving scrapers. Powered shovels are able to shovel away snowbanks and ridges and when outfitted with scrapers they are slow-moving scrapers.
From this it should be clear, that there is a considerable need for snow removal equipment, which can remove snow at full speed, where conditions allow, and remove sufficiently at slow speed, when conditions do not allow greater speed. Also there is a considerable need for snow removal equipment, which can effectively operate with different hindrances on the roadside, for example cars, which have stuck in the snow and have been left behind, guardrails along the roadside, traffic signs, trees and such things, and generally all hindrances in areas, which are to be cleared or which snow ridges will cover. The purpose of the invention is to create such an equipment. Such equipment is capable of clearing the road at full speed when conditions allow and at slow speed without forming ridges and is capable of clearing stuck cars and hindrances of any kind, all without the necessity of other equipment.
SUMMARY OF THE INVENTION
The invention proposes expelling air at the scraper and blowing away the snow, which has been lifted by the scraper, without letting the snow enter into and go through the blower. The snow is 100 to 500 times as heavy as air and the blower depends on only the one specific weight and has low efficiency against the other. The invention presumes constructing the blower for air and transferring its kinetic energy onto the snow, where it is in floating form and in motion in relation to the scraper and therefore mixing the two components easily. It is remarkable, that a scraper can effect 25 m 3 /sec. Snow removal equipment according to the invention can effect 25 m 3 /sec of snow, does not form a ridge and thereby eliminates the snow blower, and clears around hindrances at the roadside and thereby performs in a manner which even the snow blower cannot and thus revolutionizes snow removal. The invention will now be described by means of the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of the snow removal apparatus.
FIG. 2 shows a top view of the scraper with the air channel in the middle of the scraper blade.
FIG. 3 shows a side view of the scraper in cross-section.
FIG. 4 shows a side view of the scraper in cross-section with the air channel to the side and behind the scraper blade.
FIG. 5 shows a top view of the scraper of the previous drawing.
FIG. 6 shows a side view of the scraper in cross-section with the air channel in front of the scraper blade.
FIG. 7 shows a top view of the scraper in which the air channel is in front of the scraper blade.
FIG. 8a shows a top view of a conventional scraper blade.
FIG. 8b shows how snow moves along the conventional scraper blade.
FIG. 8c shows how snow compresses along a conventional scraper blade.
FIG. 8d shows the resultant path from a conventional scraper blade.
FIG. 9a shows a top view of a scraper blade having the air channel in the middle.
FIG. 9b shows how snow moves along the scraper blade shown in FIG. 9a.
FIG. 9c shows how snow compresses along the scraper blade shown in FIG. 9a.
FIG. 9d shows how snow compresses along the scraper blade shown in FIG. 9a.
FIG. 10a shows a top view of a scraper blade having the air channel expel the snow behind the scraper.
FIG. 10b shows how snow moves along the scraper blade shown in FIG. 10a.
FIG. 10c shows how snow compresses along the scraper blade shown in FIG. 10a.
FIG. 10d shows the resultant path from the scraper blades shown in FIG. 10a.
FIG. 11 shows a top view of a scraper blade having no inclination.
FIG. 12 shows the resulting pile of snow in section deposited to the side of the road.
FIG. 13 shows using transport equipment with the snow removal equipment.
Similar reference characters denote corresponding parts throughout the specification and drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the scraper 1 comprising an arcuate, open front member adapted to be disposed generally transversely of the path of movement and which is connected to the conduit or air channel 2 powered by an air blower 3 on the vehicle 4, which is outfitted with standard fixtures for the scraper. The scraper 1 has laterally adjacent expelling air openings 5 therein provided with movable closing doors or blades 6 and is fitted with extendible blades or flaps 7 and 8 at the top and at the sides or ends, respectively. The scraper is inclinable around the axis 15 and is able to push and blow to right and to left.
FIG. 2 is a top view of the scraper showing adjustable top extendible blades 7 and closing blades 13. The air channel 9 is located around the inclination axis 15 adjacent the fixture mechanism 16 to the vehicle. 12 is an adjusting lug.
FIG. 3 is an end elevation view of the scraper. The extendible top blades 7 and the flaps 11 depending from the scraper blade are adjustable by the pistons 10. The air channel 9 opens through the scraper apertures 5 and the expelled air having a direction 14 impacts the snow 17, which is floating up from the scraper 1.
FIG. 4 shows the scraper 1 with the extendible blades 7 and the flaps 11 and with the inclination axis 15 and the mounting fixtures 16, where the air channel 2 is behind the scraper 1 and the snow 17 is floating through the channel apertures 19 from the scraper into the wind channel 2.
FIG. 5 is a top view of this type, where 18 is the expelled beam of snow and air. When the snow mixes into the air, the velocity is reduced and the volume increases and therefore the cross section of the air channel must increase accordingly.
FIG. 6 shows the scraper 1 with the extendible blades 7 and flaps 11, where the air channel is in front of the scraper blade or lower or rear portion, and the scraper blade 1, the extendible blades 7 and the flaps 11 are forming the air channel or limiting it outwardly.
FIG. 7 is a top view of this type. The scraper 1 and the extendible blades 7 are forming the air channel 2 and are forming the expelled beam 18. The snow is floating upwards along the scraper blade 1 and floats into the wind channel 2. The velocity of the expelled beam 18 becomes approximately a 1/9 part of the velocity of the unmixed air in the air channel 2 in the case of lightweight new snowfall and the same volume of snow and air. The velocity of the expelled air-beam becomes higher if the scraper 1 is inclined, and then the scraper is capable of throwing away even ice, although it does not mix into the expelling air.
If the scraper is stationary, there is no snow mixing into the wind channel 2 behind the scraper blade or in front of the scraper blade, and the velocity of the expelled air is reduced to a half, if the section of the wind channel is not reduced by means of the extendible blades 7. This velocity is sufficient to blow away uncompressed snow from hindrances on the roadside. On the contrary any air velocity is insufficient to blow away compacted snow. It must first be cut loose. On the road, that is the purpose of the scraper, but where the scraper cannot reach, the airstream is strongest from the apertures 5 in the scraper blade 1 of FIG. 1. On the contrary a full pressure from the blower can be utilized through a special nozzle, whose only purpose is to clear snow from stationary objects. FIG. 7 is a top view of the scraper of FIG. 6. The scrapers of FIGS. 5 and 7 are most suitable if inclinable or inclined. In an inclined position a part of the kinetic energy of the snow is utilized for expelling and the expelling velocity is increased but the width of the cleared path is reduce.
In FIGS. 8b, 9b, and 10b an attempt is made to display visually the resistance in front of the scraper, and in FIGS. 8d, 9d, and 10d a section in the cleared path and snow ridges. FIGS. 8a, 9a, and 10a display the scraper types, FIGS. 8b, 9b, and 10b show how the snow from the paths a, b and c is moving along the scraper blade, in FIGS. 8c, 9c, and 10c show the snow compressed and in FIGS. 8d, 9d and 10d a section of the cleared path and snow ridges. FIG. 12 displays the volume of snow in section, which is opposite the expelled beam for the clearing of the roadside, outside the road.
FIG. 8a displays a conventional scraper, where the same snow up to 4 times meets the scraper, which each time throws the snow forward with a velocity of double the velocity of the vehicle, and where the scraper generally has a 2:5 fold depth of snow in front of itself, in relation to the snow in front. This requires a high force from the vehicle.
FIG. 10a displays the type, where the expelled air is behind the scraper. The scraper is not pushing any volume forwards, but is lifting the snow upwards approximately the depth of the snow and then the expelling air takes care of throwing the snow away. The snow is not propelled forwards and therefore almost no force is needed from the vehicle. Therefore these scrapers can be proportionally wider.
A scraper according to FIGS. 1, 2 and 3 is displayed in FIG. 9a. It pushes forward approximately half the volume of the conventional scraper according to FIG. 8a and therefore needs one-half of its force and has high expelling force sidewards outside the road, because the nozzle is near to the roadside and exerts a great velocity. On the other hand the snow is compressed at the nozzle and develops clumps and therefore does not mix into the air as well as with equipment according to FIG. 10a, where the snow is almost uncompressed.
Equipment according to FIGS. 6 and 7 is not displayed on these comparing figures wherein that equipment pushes the snow forwards in front of itself one turn and then it is expelled away.
Thus the invention includes three new methods in addition to the method of the conventional scraper. Each method has its own characteristics, needs its own vehicle force and is treating the snow in its own way, can clear its own width, has its own bulk, but common to all of them is that they do not form ridges, are effective at any velocity and are friendly against the vehicle, where conventional scrapers are very demanding. Existing vehicles are heavy trucks carrying full load for providing weight and frictional force against the snow, and their motors are propelling at full power, conventionally 20 tons at the highest speed allowed, which is 80 km/hr. Equipment according to the invention can be forced by the smallest trucks or small pickups, only loaded by the blower and its motor and weighting totally approximately 4 tons. Snow removal costs are even to the costs of the vehicle and the costs of the motor of the blower and totals only to hardly one-half of the previous expenses. It may be mentioned, that the most suitable motor for the blower is a motor from a usual truck, and blowers are inexpensive gear. Cutting the costs to one-half is quite a revolution.
FIG. 11 displays a scraper according to the invention having no inclination.
FIG. 12 shows snow removal equipment according to the invention intended for also lifting the snow upon associated transport equipment, for example a big wagon, for transporting away. This type is suitable in towns and densely populated areas, where the snow must be transported away. This has usually been done by first scraping into snow ridges and then lifting the snow with a shovel or a snow blower upon a transport wagon. Equipment according to the invention takes care of this in one operation. by cleaning up with scraping and lifting directly upon a wagon.
The wind channel behind the scraper has in each section an area according to the volume and speed passing through. The same applies to the scraper blade, when the wind channel is on the front side.
The invention can be used for V-formed snowplows to make channels through large snowbanks. There is a hole for expelling air in the center with the beam directed to both sides, and in front of the hole there is a coverplate which prevents the snow from entering the opening. The opening is uppermost in the blade and the direction of the expelling beam is almost horizontal along the blade.
When the vehicle is a truck, it is suitable to propel the blower by its own motor, both mounted on the same framework, which can be lifted upon the platform and then connecting the air channel to the blower and the scraper. The air channel must always be flexible, so that the scraper can be lifted and inclined.
When the vehicle is a tractor, it is suitable to propel the blower by the power shaft and connect the blower thereto by a link.
A blower connected to a motor can be mounted upon a frame on wheels and trailed by any vehicle, and the scraper can be connected to the frame or bumper support. The scraper is subjected to only a small force from the snow, because the blade only cuts the carpet of snow from the surface, but does not compress the snow as before.
A small motored blower can be mounted upon a wheeled frame powered forward and steered by hand like a lawn mower. This is possible because of the small force from the snow. This is not possible by the old pushing method, because there is needed a weight and a driving force to build up a pressure against the snow and push it to the side out of the road. This is what the expelling air takes care of according to the invention.
Equipment according to the invention can be mounted upon a usual road planer, and equipment for special use can also be provided.
Regarding excavators and similar machinery on wheels it is suitable to propel the blower by its own motor and mount the blower and motor upon the main frame. An existing motor is always an advantage, because vehicle and blower are running at different revolutions and a power shaft and drive belt are often difficult to adapt.
In towns and villages the snow must be transported away. According to the invention this is done by means of an exhaust channel similar to the usual snow blowers. The channel is directed upwards and is directing the snow onto a truck's platform beside the vehicle or behind it. With such, there is a low speed and output accordingly.
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A method and apparatus for removing snow from roadways and the like includes the provision of a curved scraper blade having top and bottom edges and defining a generally circular passageway forward of the blade extending longitudinally the length of the blade. Forward movement of the blade causes the bottom edge to lift up snow from the roadway and as it is urged into the passageway, pressurized air from an air blower is expelled into the passageway, causing the snow therein to be expelled laterally of the scraper blade and over the roadside. The pressurized air may be expelled into the passageway through one or more apertures in the blade intermediate its ends or alternatively, through an aperture at either end of the blade. An extendible top blade on the scraper blade permits variation of the overall blade and passageway configuration to accommodate different snow conditions while the scraper blade is angularly displaceable about a central vertical axis to alter the lateral discharge path of expelled snow from the passageway.
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] The United States government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided by the terms of an applicable contract.
TECHNICAL FIELD
[0002] The present invention relates generally to aerospace technology and more particularly, the present invention relates to hydrogen powered high altitude aircraft.
BACKGROUND
[0003] Certain specialized aircraft are designed to fly long distances and stay aloft for long periods of time. These are sometimes known by the acronym “HALE”—high altitude long endurance. However, the aircraft need not necessarily fly at high altitudes. These aircraft are typically unmanned, remotely controlled and are useful or potentially useful in a variety of applications. For example, in surveillance to conduct aerial patrols along a border, or along a coast of a nation or state, or in remote areas to act as a substitute for a “cell tower” for cellular communications. For such uses, it is desirable that these aircraft have the capability to remain aloft for long periods (more than about three days) and traverse a significant area during that time. Accordingly, the aircraft carry a relatively large quantity of fuel to enable long endurance, whether deployed at high or low altitude.
[0004] Typically, these aircraft present a large external surface area: they tend to have very large wings relative to fuselage length, typically more than about 3.0. Because fuel is typically stored in the wings, the design of these large wings is generally a compromise between the requirements of “lift” to launch and maintaining the aircraft aloft, and the requirement for fuel storage. In these types of craft there is an additional trade off between reduction in weight (and hence fuel requirements) to extend mission capability versus the increased weight necessary to carry sufficient fuel for long endurance. One approach to meeting these conflicting requirements might be to use solar power but technology to demonstrate flight longer than about 24 hours has not yet been developed. The use of lighter than air stratospheric airships has been proposed but while these achieve high altitude and can stay aloft for days, they are expensive and susceptible to cross winds and so lack the path stability required to carry out missions that require a fixed path of flight.
[0005] Accordingly, it is desirable to develop an aircraft that could be deployed at high or low altitude that has long endurance and directional stability under most of the expected conditions encountered when aloft. In addition, it would be a benefit if the wings could be designed optimally for flight conditions rather than as a compromise with necessary fuel carrying capability in the wings. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
BRIEF SUMMARY
[0006] This invention provides unmanned hydrogen powered air vehicles that in some embodiments can fly very long endurance (10 or more days) at altitudes over 60,000 ft carrying significant payloads of up to 2,000 pounds. Embodiments may include features such as large wing spans relative to fuselage (3.0 and greater) and an all composite or partial composite structure for light weight and strength. An embodiment of the aircraft uses one or more internal combustion engines adapted for hydrogen combustion, each engine driving propellers. The hydrogen fuel is stored on board in containers, located within the fuselage, as a cryogenic liquid, and is vaporized in a heat exchanger before charge to the internal combustion engine. In some embodiments, these features enable the craft to provide more than 10 days endurance.
[0007] Embodiments of the aircraft may include one or more combination or all of several unique features: a hydrogen powered engine; on-board fuel storage of liquid hydrogen in cryogenic containers such as vacuum Dewar fuel tanks; high aspect ratio wings incorporating a high performance laminar flow airfoil; a primarily composite, very light-weight airframe structure; and continuous operation as an unmanned, autonomous flying vehicle for up to about 10 days.
[0008] Embodiments of the invention can provide unprecedented flight endurance, ranging from over 30 days of endurance capability at altitudes near sea level to 10 days at 65,000 ft altitude, all while carrying a mission communications and payload suit weighing approximately 1,000 lbs. Additionally, embodiments of the air vehicles may include sufficient reliability and/or redundancy of its systems to maintain very-high mission reliability of greater than 90%, if required, over its multi-day flight endurance. The long endurance at high altitude, coupled with its significant payload capacity will allow the air vehicle to provide significantly lower cost solutions in communications, surveillance, data relay and like applications
[0009] The above and other aspects of the invention may be carried out in one form by an embodiment that is a winged aircraft with a fuselage that encloses a cryogenic container adapted to contain liquid hydrogen; a heat exchanger in fluid communication with an interior of the container, the heat exchanger adapted for receiving liquid hydrogen from the container; and an engine in fluid communication with the heat exchanger, the engine adapted for combustion of gaseous hydrogen as fuel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures.
[0011] FIG. 1 is a schematic perspective view of a high altitude aircraft depicting the long wingspan;
[0012] FIG. 2 is a partial cross sectional view of an aircraft fuselage according to an embodiment of the invention depicting hydrogen fuel storage containers;
[0013] FIG. 3 is a block diagram depicting a flow scheme for supplying hydrogen fuel to the engine according to an embodiment of the invention;
[0014] FIG. 4 is a block diagram depicting a flow scheme of a coolant system for a hydrogen powered aircraft, according to an embodiment of the invention;
[0015] FIG. 5A is a cryogenic tank in partial cross section depicting double walled structure and support pillar, in accordance with an embodiment of the invention; and
[0016] FIG. 5B is a cross sectional view of a portion of the tank of FIG. 5A showing internal insulation.
DETAILED DESCRIPTION
[0017] The following detailed description is merely illustrative in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
[0018] The invention may be carried out in one form by an embodiment that is a winged aircraft with a fuselage that encloses a cryogenic container adapted to contain liquid hydrogen; a heat exchanger in fluid communication with an interior of the container and adapted for receiving liquid hydrogen from the container; and an engine adapted for combustion of gaseous hydrogen as fuel, in fluid communication with the heat exchanger.
[0019] FIG. 1 depicts schematically an aircraft 100 of the type useful in the invention: it has a fuselage 110 and opposed wings 120 extending from the fuselage 110 . The aircraft further has a tail section 125 that includes a rudder 126 and a pair of rear stabilizers 128 (seen more clearly in FIG. 2 ). The aircraft wings 120 are long in comparison with the length of the fuselage 110 , as is typical in long endurance high altitude aircraft. Typically, but not necessarily, these types of aircraft 100 have a wingspan to fuselage length ratio of 3.0 to about 4.0. While these are characterized as “high altitude” aircraft, meaning they are intended to fly at heights of about 35,000 ft. or more, often 65,000 ft., above sea level, they are also useful at lower altitudes, closer to sea level. The fuselage may comprise a central portion of the aircraft, and various embodiments that include a blended wing body or flying wing do not depart from the scope of the invention.
[0020] The embodiment shown in FIG. 1 also has a pair of engines 122 , each driving a propeller 123 and each having a nacelle 124 . Of course, other aircraft embodiments may have a single engine or may have a pair of engines on each wing. Thus, the number of engines is not a limiting factor except that use of a pair of engines provides both redundancy in case of engine failure as well as light weight to conserve fuel for a multi-day long mission.
[0021] As explained below, the engines 122 are adapted to hydrogen fuel. Fuel is stored on board the aircraft 100 in cryogenic tanks 300 , shown in FIG. 2 in liquid form, at a pressure of about 30 psi, or other suitable pressure deemed safe and useful. While two tanks 300 are shown, and while these are spherical, one or more tanks of different shapes may be used. As shown, the tanks 300 are contained within a space or cavity formed in the fuselage 110 . In the example, one tank 300 is ahead of the wing attachment location 130 , and the other tank 300 of equal size is rear of wing attachment location 130 . This controls the location of the center of mass of the craft 100 to permit stable flight of the craft. During flight, fuel may be taken from both tanks 300 equally or alternately from each to maintain the center of mass of the craft in a location that ensures craft stability. The nose 150 of the particular aircraft 100 illustrated is adapted to contain control equipment 155 and other equipment ancillary to a mission of the aircraft.
[0022] In the embodiment of FIG. 2 , the aircraft 100 is of light weight construction and is made up of a series of skin panels 164 stabilized by a series of underlying supporting frames 160 with longitudinal longerons 162 extending between the frames 160 . Together with the skin 164 , these frames 160 and longerons 162 form the aircraft fuselage 110 . Frames 160 and longerons 162 also provide hard points for the attachment of fuel tanks, landing gear, systems and payload and distribute the loads into the skin 164 . The fuselage shape is selected to conform to a desired (lateral) cross sectional shape of the aircraft that meets several purposes, for example: aerodynamics (drag reduction, etc.) and the mission (size of tanks to carry fuel, for example). Accordingly, the frames 160 are of a shape that are approximately oval in some embodiments, but can vary. To meet the lowest weight criteria while meeting strength requirements, the frames 160 may be fabricated of composite materials, such as carbon fiber impregnated with a suitable engineering polymer such as polyaryletherketone, or epoxy and the like. The frames 160 may alternatively be made of a strong light weight metal alloy, such as an aluminum or titanium alloy. As many longerons 162 as necessary may be used to make a sound structure for fuselage 110 . The longerons 162 may likewise also be of composite materials or may be of a strong light weight metal alloy, such as an aluminum or titanium alloy. Similarly, the skin panels 164 may be of a graphite or fiberglass/epoxy composite sandwich or another composite or light weight metal. Of course, a combination of materials may also be used to take advantage of properties and to achieve a light weight aircraft that meets a reasonable or acceptable cost as balanced against the added fuel consumption and reduced range of a heavier craft.
[0023] Because embodiments of the aircraft of the invention have hydrogen tanks located within the fuselage, the wings can be designed for optimum performance without any compromises with regard to fuel carrying capacity as was the case with aircraft that have fuel tanks within the wings. Accordingly, embodiments of aircraft in accordance with the invention may have high aspect ratio wings incorporating a high performance laminar flow airfoil that might otherwise not be possible.
[0024] With regard to the hydrogen-adapted internal combustion engine, any reliable automotive or aircraft engine may be adapted for this purpose by making appropriate modifications. In addition, as with any modern engine, the engine should have an engine control module (“ECU”) that may be modified to take into account the characteristics of hydrogen fuel. Further, to ensure sufficient power, the engine should desirably but not necessarily have compression turbines that increase engine intake air pressure, and these should have intercoolers to remove heat of compression and to permit cooler air feed to the engine, as shown below in the description of FIG. 4 .
[0025] As shown in FIG. 3 , a simplified flow diagram of an embodiment of the fuel system, the fuel tanks 300 each feed into a common outlet conduit 302 that is in communication with suction sides of pumps 310 . The pumps 310 charge liquid hydrogen to a hydrogen reservoir 312 that has appropriate safety features, such as a vent system. Reservoir 312 has a safety vent 311 and is pressured by the pumps 310 to a pressure of about 225 psi, in some embodiments. Liquid hydrogen exiting the reservoir in conduit 313 is monitored for temperature 315 and pressure 316 . The flow in conduit 313 is controllably split into each of two heat exchangers 320 by a pair of inlet control valves 321 . In the heat exchangers 320 , as explained in more detail below, the hydrogen is heated against a warmer coolant to a warmed gas for charging as fuel to the engines 122 . Gas exits the heat exchangers 320 through outlet control valves 322 in conduits 323 and 327 under control of pressure regulators 324 and 328 , respectively, to the engines 122 , 122 .
[0026] FIG. 4 depicts an example of a cooling system of the aircraft, in block diagram form, that has three loops: a pair of loops that are identical and that cool the turbine compressors of each engine, and a third loop that maintains the environment for avionics boxes and payload boxes. The cooling system depicted uses a continuously recirculating liquid coolant, such as a mixture of propylene glycol and water, for example. This coolant is continuously circulated to collect heat that must be removed and is then subjected to cooling to remove the collected heat. The coolant is therefore reused in a continuous controlled cycle.
[0027] In general, heat must be removed from the engines 122 , turbo compression system 171 - 175 of each of the engines 122 , and also from the environmental control system 260 , while heat must be added to the liquid hydrogen to convert it to a gaseous form for combustion. Accordingly, the coolant removes waste heat and applies that heat to the hydrogen gasification. Excess heat from the system is expelled to the environment.
[0028] Referring to the illustrated example that is based on a two-engine embodiment, three stages of air compression are used for each engine. The coolant system for each engine is identical to that of the other, and so only one will be explained in detail. Ram scoop air enters a low pressure compression turbine 171 and compressed heated air exits and flows to low pressure compression intercooler 172 . The cold coolant is in a cold coolant header 202 . Header 202 has a conduit 203 that diverts cold coolant to low pressure compression intercooler 172 , a heat exchanger which transfers heat from the air to the coolant that exits via conduit 204 to heated coolant header 220 . Cooled compressed air exiting the intercooler 172 enters an intermediate stage compression turbine 173 where it is compressed to a higher pressure and heated as a result of compression. The exiting heated air from turbine 173 enters an intermediate pressure intercooler 174 , where the air is cooled by heat exchange with cold coolant supplied via conduit 205 from header 202 . Warmed coolant exits intercooler 174 as heated coolant in conduit 206 and flows to header 220 . Next, the cooled air exiting intercooler 174 enters a final high compression turbine 175 where it is further compressed and undergoes heating as a result. The heated exiting air from turbine 175 enters a high pressure intercooler 176 that transfers heat from the air to the coolant that enters intercooler 176 from header 202 via conduit 207 and exits the intercooler 176 as heated coolant via conduit 208 to header 220 . Air exiting the intercooler 176 is delivered to an engine intake (not shown) at a pressure and temperature suitable for efficient engine operation.
[0029] Heated coolant in conduit 220 is drawn to the suction of pump 224 which pumps the hot coolant into a radiator 230 which is air cooled. The coolant is cooled to an extent necessary to retain sufficient heat to vaporize liquid hydrogen and to allow temperature control of the environmental system 260 , illustrated as including the avionics boxes 256 and the payload boxes 258 . Cooled coolant exits the radiator 230 and the flow is controlled to divide into three conduits: one conduit returns to header 202 for use in cooling the turbo compression system (as described above for each engine 122 ) so that the cycle repeats; a second conduit 250 to cool the environmental systems, and a third conduit 270 to supply heat to the liquid hydrogen.
[0030] As described above, with reference to FIG. 3 , the liquid hydrogen is generally heated to a gaseous form in heat exchangers 320 . Referring now to FIG. 4 , the cooled but not cold, coolant in conduit 270 exiting radiator 230 retains sufficient heat to gasify the hydrogen liquid. The coolant enters heat exchangers 320 and exits as further cooled coolant in conduit 272 , having lost heat to the liquid hydrogen. This coolant is routed from conduit 272 into conduit 220 , and hence to pump 224 . Pump 224 sends coolant back to radiator 230 . From radiator 230 , some of the coolant exits to conduit 270 so that the cycle is repeated.
[0031] A controlled portion of the coolant from radiator 230 entering conduit 250 is charged to a dual core heat exchanger 252 , although other types of heat exchangers may also be used. This radiator-cooled coolant is then circulated by pump 254 via coolant header 255 to the environmental control system 260 that includes avionics boxes 256 and payload boxes 258 , where the coolant picks up heat. The heated coolant circulates back to the heat exchanger 252 , via heated coolant header 259 , where it is cooled. A portion of the coolant exiting heat exchanger 252 enters the suction of pump 254 and is recirculated back to the environment 260 , repeating the cycle. Another portion flows via conduit 253 to conduit 220 for recycle via pump 224 to air cooler 230 . Other arrangements of the cooling system, including systems with a fewer or greater number of components, do not depart from the scope of this invention.
[0032] As shown in FIG. 5A , an embodiment of a cryogenic tank 300 depicted in partial cross section has an inner spherical wall 350 and a surrounding outer spherical wall 370 with an annular space 375 between the two walls. The inner wall 350 is supported away from and by the outer wall by a central vertical double-walled pillar 352 . The use of a single support pillar 352 minimizes conductive heat transfer from the outer wall to the inner chamber 355 . The inner chamber 355 contains liquid hydrogen to a height measured by a capacitance gauge 358 , when the tank 300 is in use. The annular space 375 is at a near complete vacuum, with a pressure as low as 1×10 −6 torr, to reduce heat transfer through the annular space. In addition, as shown in FIG. 5B , in some embodiments the space 375 may be filled with a thermal insulating material, such as for example fiber glass or epoxy, or alternating layers of perforated, double side aluminized polyimide film such as Kapton® 376 (a trademark of Dupont of Delaware, available from MPI Technologies Inc. of Winchester, MA) and polyester netting such as Dacron® (a trademark of Invista North America of Wichita, KS, available from Apex Mills, of Inwood, N.Y.) netting 378 , or other suitable thermal insulation product or combination of products that has a desired low heat transfer.
[0033] The liquid hydrogen cryogenic tanks 300 should also be fitted with other ancillary and safety equipment as dictated by good engineering practices, for example a vent system to prevent over pressurization, a ground fill and drain system, recirculation system and supply system.
[0034] In one embodiment, the invention provides an aircraft that has a fuselage and wings extending from the fuselage; a cryogenic container adapted to contain liquid hydrogen; a heat exchanger receiving liquid hydrogen from the container which is in fluid communication with an interior of the container, the heat exchanger; and an engine mounted to the fuselage or wings that is adapted for combustion of gaseous hydrogen as fuel.
[0035] Optionally this embodiment may include several features such as an intercooled compression system supplying compressed intake air to the engine. The container may be located in a cavity within the fuselage. The container may be a double-walled container with a reduced pressure region approximating a vacuum between the walls. The container may have an inner wall of aluminum alloy. An annular space between the inner wall and a surrounding outer wall may have an insulation material therein. The insulation material may include alternating layers of polyimide and polyester insulating material. The engine may be an internal combustion engine. The heat exchanger may be in fluid communication with coolant that contains heat removed from air compression turbines. The heat exchanger may be configured to transfer heat from the coolant to liquid hydrogen to convert the hydrogen liquid to hydrogen gas. The aircraft may have a pump with a suction in fluid communication with an interior of the container and an outlet in fluid communication with the heat exchanger so that when the aircraft is in use, the pump charges liquid hydrogen to the heat exchanger and the heat exchanger supplies gaseous hydrogen to the engine.
[0036] In another embodiment, the invention provides an aircraft that includes a fuselage and wings extending from the fuselage; a cryogenic container adapted to contain liquid hydrogen; a pump having a suction in fluid communication with an interior of the cryogenic container and adapted for pumping liquid hydrogen; an engine adapted for combusting gaseous hydrogen as fuel; a cooling system that has a circulating coolant that removes waste heat generated by air compression and hydrogen combustion; and a heat exchanger, in fluid communication with a discharge of the pump and with the coolant, to transfer heat from coolant to liquid hydrogen when the aircraft is in use.
[0037] Optionally, this embodiment may include several other features including an inter-cooled compression system supplying compressed intake air to the engine. The container may be a double-walled container with a vacuum between the walls. The container may have an inner wall comprised of an aluminum alloy. An annular space between the inner wall and an outer wall may have an insulation material therein. The insulation material may be alternating layers of polyimide and polyester insulation material.
[0038] In yet another embodiment, the invention provides an aircraft that has a fuselage having wings extending from the fuselage; a cryogenic container adapted to contain liquid hydrogen and located within the fuselage, the container has at least an inner wall surrounded by and spaced from an outer wall, with an annular space between the inner and outer walls having an insulation material, the outer wall supporting the inner wall; a pump having a suction in fluid communication with an interior of the cryogenic container adapted for pumping liquid hydrogen; an internal combustion engine adapted for combusting gaseous hydrogen as fuel; an inter-cooled turbo compression system supplying compressed air to the engine; and a heat exchanger is in fluid communication with a discharge of the pump, and a coolant, to transfer heat from coolant to liquid hydrogen when the aircraft is in use.
[0039] Optionally, the embodiment may also include a hydrogen reservoir intermediate the pump and the engine, where the reservoir receives liquid hydrogen from the pump and is in fluid communication with the heat exchanger.
[0040] While at least one example embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the example embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.
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Hydrogen powered air vehicles that in some embodiments can fly with very long endurance (10 or more days) at altitudes over 60,000 ft carrying payloads of up to 2,000 pounds. Embodiments may include features such as large wingspan relative to fuselage and an all composite or partial composite structure for light weight and strength. The aircraft of the invention use one or more internal combustion engines adapted for hydrogen combustion, each engine driving propellers. The hydrogen fuel is stored on board in containers, located within the fuselage, as a cryogenic liquid, and is vaporized in a heat exchanger before delivery to the internal combustion engine.
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This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/SE01/02351 which has an International filing date of Oct. 26, 2001, which designated the United States of America, and which claims priority on Swedish Patent Application No. 0004072-5 filed Nov. 3, 2000, the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention generally relates to a method and a system for the control of a flow of metal. More preferably, it relates to the control of a flow of molten metal in a space defined by a tubular device, such as a pipe and/or, in particular, a pouring nozzle or a submerged entry nozzle.
BACKGROUND OF THE INVENTION
In the metallurgical industry there are different processes in which liquid metal is to be processed in one way or another. One example is the casting of metal, such as steel. In part of such a casting process, the liquid metal is supplied from a ladle via a pouring nozzle to a tundish. The metal flows from the tundish via a pouring nozzle to a casting mould or chill mould, in which the metal is cooled and transformed into solid form.
The supply and the flow of the metal through the pouring nozzle is very important in order to produce a configuration of flow in the chill mould that gives optimal conditions as regards the solidification of the metal and as regards the use of additives, such as casting powder or lubricant.
Moreover, it is important to prevent solid material, such as aluminium oxides, from accumulating on the inside of the pouring nozzle and in its outlet openings. Such solid material can, on the one hand, cause clogging of the pouring nozzle and the openings and, on the other, affect the flow and thus the casting process and the quality of the end product.
By way of today's technique, it is a problem to ensure that a metal flow which is located in the pouring nozzle is favorable for the casting process, since the metal is hidden or not visible as it flows through the pouring nozzle. Attempts are made to estimate what the flow looks like inside the pouring nozzle by, for instance, water modelling or mathematical modelling. However, these methods mostly take stationary conditions into account. In reality, marked variations can arise in the flow due to, for example, interference from a flow-controlling unit, such as a stopper or sliding gate, asymmetry in the flow, a varying level in the tundish and clogging of the nozzle.
Usually some form of gas, such as argon, is injected into the pouring nozzle in order to prevent clogging. However, this results in a secondary effect, implying that the flow then can change.
SUMMARY OF THE INVENTION
An object of an embodiment of the present invention is to provide a method and a system for the control of the metal flow through a defined space, which will obviate the problems mentioned above.
The above-mentioned object may be achieved according to an embodiment of the invention, by a method and a system.
According to one aspect of the invention, a method is thus provided for controlling a gas-containing flow of molten metal in a space defined by a tubular device, which may therefore be hidden or not visible, for example, preferably inside a pouring nozzle or a submerged entry nozzle. The method comprises the steps of
measuring, for at least one predetermined layer of the metal flow in the space, at least one quantity which is representative of at least one flow factor in said layer,
obtaining values from the measured quantity, that give an indication of the appearance of the flow in said layer by comparing with stored, preferably empirically determined values, and
controlling based on the result of the comparison at least one flow-affecting parameter, such as gas supply and/or metal supply, so that a desired type of flow is produced at least in said layer.
According to another aspect of the invention, a system is provided for controlling a gas-containing hidden or not visible flow of molten metal in a space defined by a tubular device, preferably inside a pouring nozzle. The system comprises a detection device which is intended to be arranged at the tubular device in order to measure, at least for a predetermined layer in the space, at least one quantity which is representative of at least one flow factor in said layer. An evaluation device is connected to the detection device for receiving values which have been obtained from the measured quantity and which give an indication of the appearance of the flow in said layer, the evaluation device comparing these received values with stored, preferably empirically determined, values. A control device is connected to the evaluation device and is adapted to control from the result of the comparison at least one flow-affecting parameter, such as gas supply or metal supply, so that said desired type of flow is provided in at least said layer.
In this patent application, the flow factor shows itself in components active in the defined space, such as metal contents, gas contents, etc, which each separately or jointly form one or more flow states in the space.
At least one embodiment of the invention is thus based on the understanding that knowledge of the material contents, i.e. the distribution of materials in the form of metal and gas, in selected parts of the space, can give information about the actual type of flow therein. By measuring a quantity which is representative of a flow factor, such as the metal contents, an indication is obtained of the distribution of metal and gas in the space. The indication of the distribution of metal and gas, i.e. the appearance of the flow, is advantageously obtained by calculation or determination of an indication value which is based on the performed measurements and which is compared with stored, calculated or empirically determined values.
In this patent application, type of flow refers to a predetermined, identified appearance, i.e. a predetermined distribution of gas and metal, in at least some part of a flow. By determining the gas contents or the gas composition in a predetermined portion of the defined space, it is possible to determine what type of flow is involved in this portion. Subsequently, the supply of liquid metal and/or, for example, gas to the defined space can be controlled in order to modify the configuration of flow in this portion. Consequently, this results in a great difference compared with prior-art technique, in which it is necessary to perform rough estimations and in which certain changed conditions can change the configuration of flow considerably without being discovered directly.
Thus, one advantage of at least one embodiment of the present invention is that it can continuously take changes into account and control flow-affecting parameters accordingly. For example, a beginning clogging can be discovered at an early stage and be quickly counteracted before the interference has become too large.
According to a further aspect of the invention, a flow-controlling system as stated above is used for detecting if inclusions/slag which are/is entrained by the metal accumulate/s on or clog/s a pouring nozzle, and for taking measures that counteract such accumulation of deposit/clogging.
Another advantage of at least one embodiment of the present invention is that a direct procedure is used by measuring on the actual flow unlike prior-art technique where an indirect procedure in the form of modelling is used.
Essentially three types of flow and combinations thereof as regards liquid metal in a pouring nozzle have been identified, in the cases when liquid metal flows through the nozzle and non-metallic material, such as gas, also is present. These three types of flow are: 1) bubbly flow, 2) annular centred flow and 3) annular non-centred flow. In a bubbly flow, supplied gas is diffused or distributed in the metal. An annular centred flow essentially appears in the form of a continuous metal jet surrounded by gas. The contrary applies to an annular non-centred flow where the metal flow essentially follows the walls of the nozzle and a gas is located at the centre axis of the nozzle. It may be desirable as regards a predetermined type of flow in a predetermined part of the nozzle. It has among other things turned out to be advantageous to have a bubbly flow in the lower part of the pouring nozzle since this is an essentially constant flow into the chill mould, which favours the casting process.
An advantageous way of measuring the actual type of flow is to measure on a number of layers or sections in the transverse direction of the defined space in order to learn what the distribution of material looks like in these layers. Consequently, it is a question of a type of tomography. By way of the measurement information obtained for the respective layers, it is possible to provide a picture of the flow in selected portions of the defined space and thus determine the actual type of flow for the respective portions. It should be understood that a layer can be both transverse to the tubular device, i.e. a horizontal layer, and longitudinal, i.e. a vertical layer. A further alternative is diagonal layers through the tubular device.
At least one embodiment of the invention is extremely useful in casting processes, in which liquid metal is supplied from a tundish to a pouring nozzle for teeming into a chill mould. The pouring nozzle in such processes hides the metal flow therein. The absence of insight and the lack of satisfactory possibilities of monitoring are therefore compensated for by at least one embodiment of the present invention which gives information about the distribution of materials in a layer of the flow in the pouring nozzle.
As already mentioned, a desired type of flow is produced by control of at least one flow-affecting parameter. In this patent application, flow-affecting parameters relate to such parameters that can affect the type of flow and therefore should not be limited to flow in the sense of volume per unit of time, but should relate to the appearance of the flow as such. For example, gas can be supplied in a predetermined manner so that the appearance of the flow or the type of flow is changed without the quantity of metal flowing through the space per unit of time being changed. In addition to controlling the gas supply, controlling the metal supply is an alternative method of changing or maintaining a predetermined type of flow.
The type of flow can thus be affected by changed supply of metal to the defined space. Consequently, the direction in which or the angle at which the liquid metal is supplied can be changed. Alternatively, a larger or smaller volume of metal per unit of time can be supplied by using a flow-controlling or flow-affecting unit of a suitable type. In casting a vertically adjustable stopper is a possible flow-controlling unit. When the stopper is lowered it tightens the inlet of the tubular device, i.e. a pouring nozzle, whereby metal is prevented from flowing from a container, such as a ladle or a tundish, to the pouring nozzle. However, when the stopper is elevated, the metal is allowed to flow to the pouring nozzle, the volume being dependent on the vertical position of the stopper.
Another possible flow-controlling unit is a sliding gate, which comprises apertured plates that are arranged on one another, and are displaced or rotated relative to one another. Thus, when an aperture in an upper plate at least partly overlaps an aperture in a lower plate, a metal flow is allowed through these to the pouring nozzle (the larger the overlapping, the larger the metal flow). Those skilled in the art will realise that also other corresponding flow-controlling units are possible and that these units can control quantity as well as direction of inflow. The metal flow can also be affected for example by the quantity of liquid metal in the tundish and the speed at which new metal is supplied to the tundish being controlled.
In addition, types of flow can be affected by the supply of gas to the defined space being changed. The quantity of gas which is supplied is variable, as well as the pressure at which the supply is provided. Also position and direction are factors which are important, i.e. from where the gas is supplied and, for example, at what angle to the main flow or to the walls that limit the defined space. Advantageously, the gas is supplied via a gas pipe which extends through the above-described stopper which thus also functions as nozzle. The gas can also be injected from an attaching device which is used for attaching a pouring nozzle to a tundish. Alternatively, the tundish or the pouring nozzle in itself can be provided with gas inlets at different angles. Examples of gases which can be used are inert gases, such as argon, etc.
One characteristic of at least one embodiment of the invention is that the measurement and the determination of the actual type of flow occur without contact relative to the gas and metal flow. The measurement is performed from at least one side of the defined space, such as from one side of a pipe that defines the space. However, there are many possible configurations, some of which will be described below.
In order to measure a quantity which is representative of the metal and gas contents in the space, for example electromagnetic methods of measurement can be used, in which the quantity such as an induced voltage is preferably related to the strength of the magnetic field. Another alternative is acoustical measurements, such as the use of ultrasound. Yet another alternative is vibration measurements. Further alternatives are different forms of radiation measurements, such as X-ray or gamma measurements. Other alternatives are temperature measurements or pressure measurements. A further alternative is speed measurements of the metal and gas flow. Those skilled in the art will realise that a combination of the methods of measurement indicated above also is an alternative.
The detection device which is adapted to give information about the current configuration of flow or the type of flow and which is used in at least one embodiment of the present invention preferably comprises one or more sensors. The sensors for use in connection with the measurements can be arranged in such a manner that they surround the metal flow completely or partly. The sensors can be arranged in a plane transversely to the main direction of flow of the liquid metal. Besides, the sensors can be arranged along the main direction of flow of the metal, i.e. in several planes. This is advantageous if it is desirable to detect and control different types of flow in different parts of the defined space. By measurements being performed continuously, data is obtained for such controlling. For example, when it comes to casting it may be important to know where the transition zone between centred flow and bubbly flow is located in a pouring nozzle, so that it can be ensured that there is enough time for the flow to become a proper bubbly flow before the metal flows out into a chill mould.
A method of measurement which has been found to be especially advantageous comprises the use of a sensor arrangement having coils which generate electromagnetic fields and which have been arranged round the defined space, in which the metal flows. The arrangement suitably comprises one or more combinations of transmitting coils and receiving coils. Advantageously, each coil is arranged next to or enclosing the tubular device. One or more transmitters can operate with one or more receivers. The coils can each operate with one or more frequencies. Thus, at least one first transmitting coil can generate an electromagnetic field having a first frequency to which at least a first receiving coil is tuned, while at least one second transmitting coil generates a field having a second frequency to which at least a second receiving coil is tuned. This facilitates the separation of differently placed sets of coils. The coils are preferably arranged in such a manner that ambient interference is minimised by some coils being reverse coupled and, thus, the basic signal which may contain interference is eliminated. Consequently, essentially only the signal is measured, which has been affected by the physical phenomenon to be measured.
One basic arrangement is to have a transmitting coil and two receiving coils, the receiving coils being placed in such a manner that one of them is not essentially affected by the development in the test object, whereas the other is placed so that it is at least partly affected by events taking place in the test object. Since the receiving coils are reverse coupled or balanced in a state where no influence from the test object occurs, a zero signal or a minimum signal is obtained, which serves as a basis from which measurements of the changes taking place in the test object are detected with a low degree of noise. In order to avoid the risk of phase transitions between the receiving coils when changes take place in the test object, the reverse coupling is suitably made in such a manner that a small signal on one side of the balance point is obtained.
At least one embodiment of the invention is thus suited for use in connection with metal flow control through pouring nozzles. In a basic configuration, a transmitting coil is thus arranged on one side of the pouring nozzle for generating an electromagnetic field. A first receiving coil is arranged on the other side of the pouring nozzle so that this is screened by the contents in the pouring nozzle. The pouring nozzle in itself does not essentially affect the electromagnetic field since the pouring nozzle usually is made of a ceramic material. A second receiving coil is arranged in such a manner that it is not at all screened by the contents of the pouring nozzle. The difference in strength between the electromagnetic fields detected by the two receiving coils is calculated in order to determine a value which indicates the actual type of flow. It has been found that a distinct signal is already achieved by way of the above-described basic configuration, so that a satisfactory indication of the appearance of the flow is obtained. However, more coils can be added to this configuration. Consequently, the coils can be arranged in different positions round the pouring nozzle and in combinations of one or more transmitting coils with one or more receiving coils, whereby more extensive information about the configuration of flow in the pouring nozzle is obtained.
As an alternative to the stationarily arranged coils, one possibility is to use movable coils. For example, a stationary transmitting coil is used which is arranged on one side of the tubular device and a receiving coil which is screened by the metal flow and is scanned or swept along a section of a circular path. Those skilled in the art will realise that also the contrary is possible, i.e. a scanning transmitting coil and a stationary receiving coil. Yet another possibility is that both the transmitting coil and the receiving coil are scanned. The receiving coil can, as in the above-mentioned technique, be reverse coupled to a receiving coil that is not screened.
In order to calibrate the measuring equipment, zero calibration and full flow calibration, i.e. with only air and only metal, respectively, in the defined space, are suitably performed. Moreover, calibration is carried out with respect to the three typical types of mixed flow. This calibration can be performed in a cold state by using a metal rod which is inserted into the space and thus represents an annular centred flow. In a corresponding way, a metal pipe can be inserted into the space in order to obtain representation of an annular non-centred flow. In the case of a bubbly flow, it is possible to use a metal body having non-metallic inclusions which correspond to an expected non-metallic state, such as a state of gas. This can be provided by way of a metal or a metal alloy, such as Wood's metal, and non-metallic balls cast therein, such as glass spheres.
When measuring on a metal flow in a tubular device, it is thus possible to obtain an indication of the appearance of the flow, i.e. the diffusion or the composition of gas and metal, by comparing with stored values which advantageously are determined empirically as stated above. An alternative is to use values of different types of flow determined by calculations.
An evaluation device is connected to the detection device. This evaluation device is adapted to receive signals from, for example, sensors comprised in the detection device, the actual type of flow being determined based on the received signals. The evaluation device preferably comprises suitable conventional electronics, hardware and software.
The evaluation device sends information about the actual type of flow to a connected control device. A user can feed the desired type of flow to the control device. Thus, a comparison can be made continuously between the actual and the desired type of flow. If the types of flow differ, the control device can control at least one flow-affecting, i.e. flow-type affecting, parameter. The control device can, for example, send signals to valve devices or the like. The control device preferably comprises suitable conventional electronics, hardware and software.
Since at least one embodiment of the present invention relates to a method and a system for the control of a gas-containing a metal flow, such as a hidden or not visible flow, for example, this does not prevent at least one embodiment of the invention from being used when the gas supply takes place passively. Unlike an active supply of gas when the operator himself chooses to inject gas into the metal flow, it is common in, inter alia, pouring nozzle couplings that air or other gases from the surroundings passively leaks into the metal flow. If an undesired flow arises in, for instance, such a leakage, this is controlled according to at least one embodiment of the invention by flow-affecting parameters, such as by an active supply of gas and metal so that the desired type of flow is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows parts of a casting plant, one embodiment of the present invention being used.
FIG. 2 shows as FIG. 1 parts of a casting plant, an alternative embodiment of the present invention being used.
FIGS. 3 a – 3 f show different alternative configurations of electromagnetic detection.
FIG. 4 shows yet another alternative configuration of electromagnetic detection.
FIG. 5 shows an exemplifying block diagram of the measurement and control of the gas and metal contents in a flow in a pouring nozzle.
FIGS. 6 a – 6 c and FIGS. 6 a ′– 6 c ′ illustrate different types of flow for a gas-containing metal flow inside a tubular device.
FIG. 7 shows a diagram of how the influence of the types of flow shown in FIG. 6 on an electromagnetic field varies with the frequency of the generated field.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically shows parts of a casting plant 10 , in which the present invention is used. A tundish 12 of the casting plant 10 is shown which contains liquid metal, such as liquid steel. A vertical pouring nozzle 14 is arranged in the bottom of the tundish 12 , through which pouring nozzle the liquid metal can flow down to a chill mould 16 . The pouring nozzle 14 is lowered into or submerged in the chill mould 16 and the lower end of the pouring nozzle 14 is located under the surface of liquid metal. In addition, the lower end of the pouring nozzle 14 is provided with outlet holes in the form of side openings, whereas its end surface 18 is closed. The side openings are adapted to produce a symmetric flow in the chill mould as the arrows 20 schematically illustrate.
A detection device 22 which is included in the system according to the invention is arranged round the upper portion of the pouring nozzle 14 . The detection device 22 is connected to receiving peripheral equipment 24 which can comprise an evaluation device and a control device. Based on the information received by the detection device 22 , the peripheral equipment 24 determines if the actual type of flow is acceptable or if a flow-affecting measure has to be taken. It may, for example, be desirable to detect any incipient clogging of the pouring nozzle 14 , in which case the type of flow changes. If such a change occurs, a flow-affecting measure is thus taken by the peripheral equipment 24 sending signals to a flow-affecting device which in the Figure is illustrated by a stopper 26 functioning in a known manner.
The stopper 26 can, in a lowered position, be made to seal the inlet 30 of the pouring nozzle 14 , thereby preventing the metal flow from flowing into the pouring nozzle 14 . The stopper 26 can in various elevated positions allow the supply of metal in different quantities. A gas conduit (not shown) having a gas outlet is suitably arranged in the stopper so that gas can be supplied to the metal flow, preferably independently of the vertical position of the stopper 26 .
FIG. 2 shows parts of a casting plant 40 , in which an alternative embodiment of the present invention is used. The parts included in this casting plant 40 have been given the same reference numerals as equivalent parts in FIG. 1 . Unlike the detection device 22 in FIG. 1 which was arranged only round the upper portion of the pouring nozzle, the detection device according to the embodiment shown in FIG. 2 comprises a detection device which are arranged at several locations along the pouring nozzle. First detection devices 42 are thus arranged around the upper portion of the pouring nozzle 14 and second detection devices 44 around the lower portion of the pouring nozzle 14 . For reasons of clarity, only these two sets of detection devices are illustrated. However, those skilled in the art realise that it is possible to arrange more detection devices along the pouring nozzle.
As the detection device 22 in FIG. 1 , the detection devices 42 , 44 are connected to receiving peripheral equipment 24 which communicates with a flow-affecting device 26 . Information about the type of flow can thus be obtained at two locations along the pouring nozzle 14 by way of the embodiment shown in FIG. 2 . For example, this is advantageous when it is desirable to ensure that the type of flow changes along the pouring nozzle 14 . It may be desirable to have an annular centred flow in the upper portion of the pouring nozzle, the gas which flows along the walls protecting the pouring nozzle from, among other things, clogging. On the other hand, in order to obtain an even flow in the chill mould 16 , it may be desirable to have a bubbly flow in the lower portion of the pouring nozzle 14 . The shown double set of detection devices can also be used for ensuring that the type of flow is the same along the pouring nozzle 14 , if desirable.
FIGS. 3 a – 3 f show various alternative configurations as regards electromagnetic detection which has been found to be advantageous when controlling a metal flow in an elongated space, such as a pouring nozzle. FIGS. 3 a – 3 f show a transmitting coil as a box filled in with stripes and a receiving coil as a blank box. The dashed lines in these figures are only intended for illustrating with which receiving coil or receiving coils located at a distance the respective transmitting coils communicate and, as a matter of fact, do not illustrate the propagation of the actual electromagnetic fields, which would make the figures indistinct.
A basic arrangement is illustrated in FIG. 3 a , a pouring nozzle 50 being schematically shown from above as a circle. On one side of the pouring nozzle 50 , a transmitting coil 52 is arranged to generate an electromagnetic field. Adjacent to the transmitting coil 52 , a first receiving coil 54 is arranged to sense the electromagnetic field which the transmitting coil 52 generates. On the other side of the pouring nozzle 50 , a second receiving coil 56 is arranged which also is arranged to sense said electromagnetic field. However, due to its location, the pouring nozzle 50 with its contents, such as liquid metal, will partly screen the transmitting coil 52 . The second receiving coil 56 will therefore detect a weaker field than the first receiving coil 54 . By reverse coupling or subtracting the signals from the receiving coils 54 , 56 , the basic signal which may contain interference is eliminated. Consequently, essentially only the signal affected by the type of flow in the pouring nozzle 50 is measured.
FIG. 3 b shows an alternative configuration, in which the transmitting coil 52 is arranged to generate an electromagnetic field and four receiving coils 54 , 56 , 58 , 60 are arranged to receive the field. Two of the receiving coils 54 , 58 are arranged adjacent to the transmitting coil 52 and are not screened by the contents of the pouring nozzle 50 . The other two receiving coils 56 , 60 are arranged on the other side of the pouring nozzle 50 , of which one receiving coil 56 is arranged diagonally to the transmitting coil 52 , whereas the second receiving coil 60 is arranged displaced to the right in the figure. If it is particularly interesting to perform measurements on one side of the pouring nozzle 50 , this is thus an advantageous arrangement. The transmitting coil 52 can generate electromagnetic fields having different frequencies, for example, by being fed with several frequencies or by scanning several frequency bands, the receiving coils being tuned in pairs (such as 54 – 56 and 58 – 60 , respectively) to the respective frequencies so that the fields detected by the receiving coils can be easily distinguished.
In FIG. 3 c yet another receiving coil 62 which is arranged adjacent to the transmitting coil 52 and a screened receiving coil 64 have been added. This further screened receiver is displaced to the left in the figure relative to the other screened receiving coils 56 , 60 , the arrangement of which corresponds to that in FIG. 3 b . By way of the arrangement in FIG. 3 c , a more complete picture of the flow section through the pouring nozzle 50 is thus obtained. Alternatively, the three screened receiving coils 56 , 60 , 64 can be replaced by one single receiving coil that scans or moves in an essentially partly circular path round the pouring nozzle 50 .
In order to obtain an even more complete picture of the flow, further receiving coils can be arranged. For example, FIG. 3 d shows five receiving coils 54 , 58 , 62 , 66 , 70 which are arranged adjacent to the transmitting coil 52 and five receiving coils 56 , 60 , 64 , 68 , 72 which are screened by the contents of the pouring nozzle 50 .
Instead of using only one transmitting coil, it is possible to use several transmitting coils as shown in FIG. 3 e . The figure shows three transmitting coils 80 , 82 , 84 . Each transmitting coil generates an electromagnetic field, preferably with a frequency that is different from the frequencies with which the other two transmitting coils generate the fields. Six receiving coils are included in this arrangement, of which three receiving coils 86 , 88 , 90 are screened by the contents of the pouring nozzle 50 and three receiving coils 92 , 94 , 96 are not screened. Each transmitting coil 80 , 82 , 84 thus has a respective receiving coil 92 , 94 and 96 , respectively, arranged adjacent to itself and a receiving coil 86 , 88 and 90 , respectively, on the diametrically opposed side of the pouring nozzle 50 , these two receiving coils being tuned to the frequency band that precisely the specific transmitting coil uses.
FIG. 3 f shows yet another configuration. In this configuration, a transmitting coil 100 , two non-screened receiving coils 102 , 104 and a screened receiving coil 106 are used. The two non-screened receiving coils 102 , 104 are reverse coupled to the screened receiving coil 106 .
Although all the arrangements shown in FIGS. 3 a – 3 f comprise reverse coupled receiving coils, those skilled in the art will realise that if an acceptable signal is obtained also without reverse coupling, the non-screened receiving coils can be left out.
FIG. 4 shows yet another alternative configuration as regards electromagnetic detection. This figure shows a longitudinal cross-section through a pouring nozzle portion 110 . A transmitting coil 112 is arranged round the pouring nozzle 110 and, in a corresponding manner, a receiving coil 114 which is placed below the transmitting coil is arranged round the pouring nozzle 110 . An electromagnetic field B, which is generated by the transmitting coil 112 , propagates inside the pouring nozzle 110 and is attenuated by the contents before the field is detected by the receiving coil 114 . As in FIGS. 3 a – 3 f it is possible to include a receiving coil which detects the electromagnetic field without influence from the contents of the pouring nozzle in order to obtain a more distinct output signal. According to the arrangement in FIG. 4 , the measurement is thus performed in vertical layers unlike the arrangements shown in FIGS. 3 a – 3 f , in which measurement is performed through the pouring nozzle in horizontal layers.
FIG. 5 shows an exemplifying block diagram of the measurement and the control of the gas and metal contents in a flow in a pouring nozzle 120 . The block diagram thus shows a sensor 122 which preferably is of the type electromagnetic sensor, acoustic sensor, such as ultrasonic sensor, vibration sensor, radiac dosimeter, such as X-ray or gamma gauge, temperature sensor, pressure sensor or speedometer, or a combination thereof. The sensor 122 passes on a flow-related measuring signal to an evaluation unit 124 which converts the measuring signal to interpretable actual values. These actual values are fed to a control unit 126 which compares the actual values with the desired values which are indicated by a user or a user unit 128 and which have been derived empirically or by calculations. Subsequently, the control unit 126 controls flow-affecting parameters based on the result of the comparison in such a manner that the desired type of flow is provided for the layer where the measurement has been performed. The block diagram shows this as a metal-flow-affecting unit 130 and two gas-flow-affecting units 132 , 134 . The two gas-flow-affecting units can, for instance, comprise a gas outlet which is adapted to eject gas at the walls of the pouring nozzle and, respectively, a gas outlet which is adapted to eject gas centrally above the pouring nozzle.
The signal processing does not in itself constitute part of the invention, but is of such type that those skilled in the art can take the appropriate measures. For this reason, the signal processing has not been described in detail and has only been illustrated schematically in the example above.
FIGS. 6 a – 6 c and FIGS. 6 a ′– 6 c ′ very schematically illustrate different types of flow for a gas-containing flow of metal inside a section of a tubular device 140 . FIGS. 6 a – 6 c show a longitudinal section of the tubular device and FIGS. 6 a ′– 6 c ′ show for the corresponding type of flow a cross-section of the tubular device. The metal is represented by dark portions and the gas is represented by light portions.
FIGS. 6 a , 6 a ′ illustrate a so-called bubbly flow, i.e. a gas 142 is diffused in liquid metal 144 , essentially in bubbly form. FIGS. 6 b , 6 b ′ illustrate an annular centred flow, i.e. an essentially continuous metal jet 144 is annularly surrounded by the gas 142 . FIGS. 6 c , 6 c ′ illustrate an annular non-centred flow, i.e. the metal flow 144 essentially follows the walls of the tubular device 140 and surrounds a gas jet 142 which flows in the centre of the tubular device 140 .
FIG. 7 shows a diagram of how the influence of the types of flow shown in FIG. 6 on an electromagnetic field varies with the frequency of the generated field. The diagram shows three graphs, graph A illustrating a bubbly flow, graph B illustrating an annular centred flow and graph C illustrating an annular non-centred flow. The diagram shows how, depending on the frequency, a metal and gas flow in a tubular device affects the electromagnetic field which a receiving device detects and gives information about in the form of an output signal. The output signal is shown in the diagram as a signal change in percentage relative to a basic signal at 100 Hz. In this case, basic signal implies that the tubular device is empty, i.e. without any metal therein.
Apparently, it is easy to distinguish the graph B (annular centred flow) from the two other ones. This depends on the fact that the metal jet in such a centred flow only gives a small cross-section for the magnetic field to penetrate and therefore this gives only a small signal change compared with the basic signal. The graphs A and C are similar to one another. In both cases, the tubular device contains a large metal cross-section, resulting in a considerable screening of the magnetic field, which leads to great signal changes. Although these two graphs are similar to one another, they exhibit considerable differences. For example, they intersect at about 550 Hz, after which graph C goes higher than graph A. This depends on the bubbles in a bubbly flow (graph A) giving better penetration for the magnetic field at higher frequencies than does a homogeneous material free from gas.
Although some preferred embodiments have been described above, the invention is not limited to them. Consequently, it should be understood that a number of modifications and variations can be carried out without deviating from the scope of the present invention defined in the appended claims.
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A method and a system are for the control of a gas-containing hidden flow of molten metal in a space defined by a tubular device. From measurements in at least one predetermined layer of the metal flow in the space, an indication is obtained of the appearance of the flow which is compared with stored values. The result of the comparison is used for controlling at least one flow-affecting parameter in such a manner that a desired type of flow is provided at least in the layer.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a conversion to regular U.S. patent application of provisional U.S. application Ser. No. 60/055,566 filed Aug. 13, 1997.
FIELD OF THE INVENTION
This invention is a device for bridging the neck of either a wide-necked or narrow-necked aneurysm in the vasculature. In general, it is a device used to stabilize the presence of vaso-occlusive devices such as helically wound coils in the aneurysm. The vaso-occlusive coils are preferably delivered by a core wire which is linked to the coils by an electrolytically severable joint. The core wire will often be insulated. The retainer assembly itself is also attached to another electrolytically severable joint and typically has a number of array elements which are intended to be resident within the aneurysm after the device is deployed from the distal end of a catheter. After deployment of this retainer, the aneurysm is at least partially filled with a vaso-occlusive device such as helically wound coils.
BACKGROUND OF THE INVENTION
Different implantable medical devices have been developed for treating a number of ailments associated with body lumens. In particular, occlusive devices are useful in filling vascular or other body spaces. Some body spaces, such as vascular aneurysms, are formed due to a weakening in the wall of an artery. Often these aneurysms are the site of internal bleeding and. catastrophically, the site of strokes. A variety of different embolic agents are known as, at least arguably, suitable for treatment of these openings. These treatments are commonly known as "artificial vaso-occlusion."
One such class of embolic agents includes injectable fluids or suspensions, such as microfibrillar collagen, various polymeric beads, and polyvinylalcohol foam. These polymeric agents may additionally be crosslinked (sometimes in vivo) to extend the persistence of the agent at the vascular site. These agents are often introduced into the vasculature through a catheter. After such introduction, materials there form a solid space-filling mass. Although some provide for excellent short term occlusion, many are thought to allow vessel recanalization due to absorption of polymer into the blood. Another procedure in which a partially hydrolyzed polyvinylacetate (PVA) is dissolved in an ethanol solvent and injected into a desired vascular site is found in Park et al. (attorney docket no. 29025-20112.00) U.S. No. patent application Ser. No. 08/734,442, filed Oct. 17, 1996, now U.S. Pat. No. 5,925, 683 for "LIQUID EMBOLIC AGENTS".
Other materials such as hog hair and suspensions of metal particles have also been suggested and used by those wishing to form occlusions.
Other materials including polymer resins, typically cyanoacrylates, are also employed as injectible vaso-occlusive materials. These resins are typically mixed with a radio-opaque contrast material or are made radio-opaque by the addition of a tantalum powder. Their use is fraught with problems in that placement of the mixture is quite difficult. These materials are ones which crosslink with the human body. Inadvertent embolisms in normal vasculature (due to the inability of controlling the destination of the resins) is not uncommon. The material is also difficult or impossible to retrieve once it has been placed in the vasculature.
Over the past few years, advancements in the artificial occlusions of vessels and aneurysms have occurred due to the delivery and implantation of metal coils as vaso-occlusive devices. Implantable metal coils that are useful as artificial occlusion devices in vasculature lumens or aneurysms are herein referred to as "vaso-occlusions coils."
Vaso-occlusions coils are generally constructed of a wire, usually made of a metal or metal alloy, that is wound to a helix. Many such devices are introduced to the selected target site through a catheter in a stretched linear form. The vaso-occlusive device assumes an irregular shape upon discharge of the device from the distal end of the catheter a variety of vaso-occlusive coils and braids are known. For instance, U.S. Pat. No. 4, 994,069, to Ritchart et al., shows a flexible, preferably coiled, wire for use in small vessel vaso-occlusion. Unlike vaso-occlusive coils used prior to that time, Ritchart taught a coil which is fairly soft and is delivered to the site using a pusher within a catheter lumen. Upon discharge from the delivery catheter, the coil may undertake any of the number of random or regular configurations used to fill the site. The coils are used for small vessel sites, e.g., 0.5-6 mm in diameter. The coils themselves are described as being between 0.010 and 0.030 inches in diameter. The length of the coil wire is typically 15 to 20 times the diameter of the vessel to be occluded. The wire used to make up the coils may be, for instance, 0.002 to 0.006 inches in diameter. Tungsten, platinum, and gold threads or wires are said to be preferred. These coils have a variety of benefits including the fact that they are relatively permanent, they may be easily imaged radiographically, they may be located at a well defined vessel site, and they can be retrieved.
It is common that these vaso-occlusive devices be delivered through microcatheters such as the type disclosed in U.S. Pat. No. 4,739,768, to Engelson. These microcatheters track a guidewire to a point just proximal or within the desired site for occlusion. The coil is advanced through the microcatheter (once the guidewire is removed) and out the distal end hole so to at least partially fill the selected space and create an occlusion.
In addition to vaso-occlusion devices or coils having predetermined secondary shapes that dictate in part their space filling mechanism, other vaso-occlusive coils have been disclosed that take on random shapes when expelled from a delivery sheath. One such type is a vaso-occlusive coil often referred to as "a liquid coil". One example of such a vaso-occlusive coil is disclosed in pending U.S. patent application Ser. No. 08/413,970, filed Mar. 30, 1995, now abandoned. This document describes a very soft and flexible coil which is flow-injectable through a delivery catheter using, e.g., saline solution.
In addition to the various types of space filling mechanisms and geometries of vaso-occlusive coils, other particularized features of coil designs, such as mechanisms for delivering vaso-occlusive coils through delivery catheters and implanting them in a desired occlusion site, have also been described. The examples of categories of vaso-occlusive coils based upon their delivery mechanisms include pushable coils, mechanically detachable coils, and electrolytically detachable coils.
One example of the type of vaso-occlusive coil referred to above as the "pushable coil" is disclosed in Ritchart et al., discussed above. Pushable coils are commonly provided in a cartridge and are pushed or "plunged" from the cartridge into a delivery catheter lumen. A pusher advances the pushable coil through and out of the delivery catheter lumen and into the site for occlusion.
Mechanically detachable vaso-occlusive devices are typically integrated with a pusher rod and are mechanically detached from the distal end of that pusher after exiting a delivery catheter. Examples of such mechanically detachable vaso-occlusive coils are found in U.S. Pat. No. 5,261,916 to Engelson or U.S. Pat. No. 5,250,071 to Palermo.
Finally, examples of electrolytically detachable vaso-occlusive devices may be found in U.S. Pat. Nos. 5,122,136 and 5,354,295, each to Guglielmi et al. In these devices, the vaso-occlusive portion of the assembly is attached to a pusher via a small electrolytically severable joint. The electrolytically severable joint is severed by the placement of an appropriate voltage on the core wire. The joint erodes in preference either to the vaso-occlusive device itself or to the pusher core wire. The core wire is often simply insulated to prevent the electrolytic response caused by the imposition of electrical current.
Further improvement upon the electrolytical detachment mechanism described just is found in U.S. patent application Ser. No. 08/205,512, filed Mar. 3, 1994 now abandoned. This document describes superimposing a modest alternating current upon the direct current signal. A sensing circuit monitors the alternating current as an indicator of the progression of coil detachment.
Improvements in enhancing the thrombogenic or other occlusive tissue response to metal coils has also been disclosed. For example, vaso-occlusive coils having fibers attached thereto are known--see, for example, U.S. Pat. No. 5,226,911 to Chee et al.
Each of the devices described above may be used in the treatment by occlusion of aneurysms. As noted above, aneurysms present particularly acute medical risk due to the dangers of potential rupture of the thin wall inherent in such an aneurysm. Occlusion of aneurysms by the use of vaso-occlusive coils without occluding the adjacent artery is a special challenge and is a desirable method of reducing such risk of rupture.
As noted above, the use of vaso-occlusive coils in treating aneurysms is widespread. These vaso-occlusive devices are placed in an aneurysm in the following fashion. A microcatheter is initially steered into or adjacent to the entrance of an aneurysm, typically aided by the use of a steerable guidewire. The wire is then withdrawn from the micro catheter lumen and replaced by the vaso-occlusive coil. The vaso-occlusive coil is advanced through and out of the microcatheter. Desirably being completely delivered into the aneurysm. After, or perhaps, during, delivery of such a coil into the aneurysm, there is a specific risk that a portion of the coil might migrate out of the aneurysm entrance zone and into the feeding vessel. The presence of such a coil in that feeding vessel may cause the undesirable response of causing an occlusion there. Also, there is a quantifiable risk that the blood flow in the vessel and aneurysm may induce movement of the coil farther out of the aneurysm, resulting in a more developed embolus in the patent vessel.
One type of aneurysm, commonly known as a "wide neck aneurysm" is known to present particular difficulty in the placement and retention of vaso-occlusive coils. Wide neck aneurysms are herein referred to as aneurysms of vessel walls having a neck or a "entrance zone" from the adjacent vessel, which entrance zone has a diameter that either: (1) is at least 80% of the largest diameter of the aneurysm; or (2) is clinically observed to be too wide effectively to retain vaso-occlusive coils that are deployed using the techniques discussed above.
Furthermore, vaso-occlusive coils lacking substantial secondary shape strength may be difficult to maintain in position within an aneurysm no matter how skillfully they are placed.
There are few disclosed devices for maintaining the presence of vaso-occlusive coils within an aneurysm. One such device is shown in U.S. Pat. No. 08/690,183, filed Jul. 26, 1996 now U.S. Pat. No. 5,980,544 for "ANEURYSM CLOSURE DEVICE ASSEMBLY" (attorney docket 29025-20162.00). That document describes a number of devices all which are said to be placed within the lumen of a feed vessel exterior to the aneurysm so to retain coils within the aneurysm cavity. That is to say that the retainer device is released in the vessel exterior to the aneurysm. The device is held in place via the presence of radial pressure on the vessel wall. After the device is released and set in an appropriate place, a microcatheter is inserted into the lumen behind the retainer device and the distal end of the catheter is inserted into the aneurysm cavity. One or more vaso-occlusive devices is introduced into the aneurysm cavity. The retainer device maintains the presence of those vaso-occlusive devices within the aneurysm no matter whether the aneurysm is a large mouth aneurysm or not.
Another device for closing an aneurysm is found in U.S. patent application Ser. No. 08/588,195, filed Jan. 18, 1996 now U.S. Pat. No. 5,749,894 for "ANEURYSM CLOSURE METHOD" (attorney docket number 29025-20136.00). In this procedure, a vaso-occlusive device such as a coil or braid has on its outer surface a polymeric composition which may be reformed or solidified in situ within the human body. The device is simply inserted into the aneurysm and the polymer is then reformed, e.g., by the application of light, to melt or otherwise to reform the polymer exterior to the vaso-occlusive device. The vaso-occlusive device then sticks to itself at its various sites of contact and forms a rigid whole mass within the aneurysm.
There are a variety of other vaso-occlusive coils and devices which may be specified herein. The material provided above is only exemplary of the patents and publications dealing with such devices. No coil retainer device of the structure described herein is seen in any of the references described above.
SUMMARY OF THE INVENTION
This invention includes an implantable medical device useful for retaining other occlusion devices at an occlusion site, such as an aneurysm, and includes related methods of introducing and installing that medical device at the occlusion site. Combinations of the retainer device and its included vaso-occlusive material or device are also an aspect of the invention. In particular, the invention involves an implantable retainer which is deliverable through an elongated tubular delivery device such as a vascular catheter. The implantable retainer typically includes a core wire having both a proximal end and a distal end. At the distal end is ajoint which extends between the distal end of that core wire and a number of array elements. The joint is electrolytically severable upon application of a suitable current to the joint. The joint is comparatively more electrolytically dissolvable when a current is applied than any of the rest of the implantable retainer components. Finally the retainer assembly itself has a number of array elements which are of a shape (a first or delivery shape) which is deployable through a delivery catheter and, upon exit from the distal end of that catheter, readily assumes a secondary shape desirably conforming to the interior shape of the aneurysm catheter. Electrolysis of the severable joint then permits placement of the retainer assembly in the aneurysm and removal of the attached delivery apparatus. Placement of the vaso-occlusive device to be retained in the aneurysm may then be had by simply introducing the vaso-occlusive device and its delivery tubular member between the array elements in the aneurysm.
The array elements themselves may be loops or may be arms which simply extend from the joint into the aneurysm cavity. It is within the scope of this invention that the retainer assembly include a number of "exterior" array members which, in general, extend radially from the region of the joint and are intended to remain in the feed vessel--not in the aneurysm--after deployment. These exterior loops define, with the interior array elements an annular area between them into which the rim or mouth of the aneurysm may fit.
The various portions of the device may be made to be radio-opaque by the choice of materials or by such other procedures as by wrapping the components in a radio-opaque wire or ribbon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are respectively a side view and a top view of a variation of the inventive aneurysm retainers.
FIGS. 2A and 2B are respectively side view and a top view of a variation of the inventive aneurysm retainers.
FIGS. 3A and 3B are respectively a top view and a side view of the inventive aneurysm retainers including in this instance arrays placed outside the aneurysm.
FIGS. 4A and 4B are show respectively a top view and a side view of the inventive aneurysm retainer.
FIGS. 5A and 5B show respectively a side view and top view of a variation of the inventive aneurysm retainer.
FIGS. 6A and 6B show respectively a side view and top view of a variation of the inventive aneurysm retainer in which the array members are not loops.
FIGS. 7A and 7B are respectively a side view and top views of a variation of the inventive aneurysm retainer.
FIG. 8 is a close-up, partial cross-section of an electrolytic joint suitable for use in the invention.
FIG. 9 is a partial cross-section of the electrolytic joint suitable for use in this invention.
FIG. 10 shows a close-up partial sectional view of an array member wrapped with a radio-opaque wire, also suitable for use in this invention.
FIGS. 11A to 11E show a method of deploying, a device made according to this invention and the vaso-occlusive devices therein.
DESCRIPTION OF THE INVENTION
This invention involves a device and procedure for solving the problem of stabilizing the structure and placement of vaso-occlusive devices when they are placed in an aneurysm. These retaining devices prevent the migration of one or more occlusion devices such as coils from a target occlusion site, by forming a barrier at the entrance zone to the target site from a feeding vessel. The remainder of the retainer device which is remote from the mouth generally provides stability to the portion of the device which is in the mouth of the aneurysm.
FIGS. 1A and 1B show typical but simple variation of the device in which the retainer assembly (100) has a shape which approximates that of the aneurysm into which it is placed. Specifically, the retainer device (100) has a plurality of array elements (102) or "interior" array elements (102) which extend from an electrolytic joint (104) and form a loop which comes around to join itself back in the vicinity of electrolytic joint (104). It is, of course, permissible to use joints other than electrolytic joints in place of (104), e.g., joints which rely upon mechanical joining for structural certainty. However, joint (104) is desirably electrolytically severable because such joints are very functionally flexible in their deployment. That is to say, that should the aneurysm retainer somehow be misplaced, the fact that core wire (106) can be used to withdraw this device back into its delivery catheter or other suitable delivery tubular member, is a significant benefit.
FIG. 1A, a side view of the inventive retainer (100), shows another aspect of this invention which is significant. In this variation, array member (102) has a proximal end (108) and a distal end (110). Similarly, as a convention here, core wire (106) has a distal end (112) which is just proximal of the electrolytic joint (104). Now as may be seen from FIG. 1A, joint (104) and core wire distal end (112) are both distally placed from the proximal end of the retainer assembly (108). This configuration has at least two benefits. First of all, the joint itselfis not placed in the feed artery and should not cause the creation of an embolus in that vessel with the danger of subsequent blockage. Furthermore, the plurality of array wires (as may be shown from the top view in FIG. 1B) form what might be characterized as a skeletal funnel a the top of the retainer device (100) and consequently in the aneurysm itself, placement or re-placement of the catheter in the retainer device so to permit introduction of the vaso-occlusive member (not shown) into the interior volume of the aneurysm retainer device is simplified.
This variation of the invention as well as the others discussed below, are delivered through a tubular member such as a catheter. The shape of the device shown in FIG. 1A is the so-called secondary shape found after the retainer device (100) has been pushed from the distal end of the delivery. The retainer device (100) generally has a relatively linear shape as is pushed through catheter. This primary or delivery shape is essentially the shape of the interior of the catheter during the delivery step. After deployment, the device assumes its secondary shape as is seen in FIG. 1A.
To undergo such massive changes in shape, it is usually preferable that the interior array elements (102) be produced of material such as a superelastic alloy. Superelastic or pseudoelastic shape recovery alloys are well known in this art. For instance, U.S. Pat. Nos. 3,174,851; 3,351,463; and 3,753,700 each describe one of the more well known superelastic alloys, also known as Nitinol. These alloys are characterized by their ability to be transformed from an austenitic crystal structure to a stress-induced martensitic (SIM) structure at certain temperatures and then return elastically to the austenitic shape when the stress is removed. These alternating crystal structures provide the alloy with its superelastic properties. The alloy mentioned in the three patents just above, is a nickel-titanium alloy. It is readily commercially available and undergoes the austenitic-SIM-austenitic transformation in a variety of temperatures between -20° C. and +30° C.
These alloys are especially suitable because of their capacity to recover elastically--almost completely--to the initial configuration once the stress is removed. Typically, in these services, there is little plastic deformation even at relatively high strains. This allows the retainer device (100) to undertake substantial bends both as it is collapsed to enter the tubular delivery device and as it undertakes further bending in passing through turns in the vasculature. In spite of this bending, it returns to its original shape once the bend has been traversed without retaining a kink or a bend.
Of the superelastic alloys currently available, we consider a preferred material to be nominally 50.6±2% nickel and most of the remainder, titanium. Up to about 5% of the alloy may be another member of the iron group of metals, particularly chromium and iron. The alloy shouldn't contain more than about 500 parts per million of oxygen, carbon, or nitrogen. The transition temperature of this material is not particularly important, but it should be reasonably below the typical temperature of the human body so to allow it to be in its austinitic phase during use. The diameter of the wires or ribbons making up the array elements preferably are smaller than about 0.010 inches in diameter. As will be discussed below in conjunction with FIG. 10, the typical superelastic alloy is not always completely visible under fluoroscopy. Consequently, it is often desirable to add some type of a covering to improve the radio-opacity of the device. Radio-opaque metals such as gold and platinum are well known.
Although we have discussed the concept that these devices are desirably made from superelastic alloys, other metals may in certain circumstances be appropriate. Such metals include a number of the stainless steels and other highly elastic, if not superelastic alloys. Furthermore, it is within the scope of this invention that the array elements (102) be of polymeric material. Polymeric materials are somewhat easier to work with in forming the device and may also suitable for maintaining the vaso-occlusive devices at an appropriate site within the aneurysm. Such materials as polyethylene, polypropylene, polytetrafluoroethylene, various of the Nylons, and the like would be easily chosen by one having ordinary skill in this art for the purposes shown herein.
The electrolytic severable joint (104) may also be called a sacrificial link. Core wire (106) is typically coated with an electrical insulator which is not susceptible to dissolution via electrolysis in blood or other ionic media. Suitable coatings for core wire (106) include such insulating materials as the polyfluorocarbons (e.g., Teflon), polyurethane, polyethylene, polypropylene, polyimides or other suitable polymeric materials. Sacrificial joint (104) is not coated with such an insulator and is of a material which is susceptible to electrolytic dissolution in blood. Joint (104) may be a simple un-insulated continuation of, e.g., stainless steel core wire (106), which has been insulated proximally of the joint. It should also be apparent that the sacrificial joint (106) is more susceptible to electrolysis than are the array elements (102). Further discussion of construction of, placement of, and other physical details of such a joint may be found in U.S. Pat. Nos. 5,122,136 to Guglielmi et al.; 5,354,295 to Guglielmi et al.; 5,624,449, to Pham et al., and others.
Although the array elements (104) are generally shown to be regular and of the approximate same shape on each of the axis through the retainer device (100), such obviously need not be the case. It is within the scope of this invention that the retainer assembly be irregular in shape so to fit the shape of an irregular aneurysm. Placement of such devices must be done with some care, but it is within the purview of one having ordinary skill in the art with some instruction.
FIG. 2A shows another variation of the inventive retainer assembly (120) in which the array elements are of two different types. Array element (122) is of the same general shape as those shown in FIG. 1A and FIG. 1B. Array element (122) extends directly into the aneurysm. Array elements (124) are paired to extend axially from the region of the joint (104). These axially extending loops (124) are also intended to fit within the aneurysm and provide directional stability to the placement of the retainer device (120). Only a single axial array element (122) is shown in FIGS. 2A and 2B. The invention is, obviously, not so limited. The generally perpendicular array elements (124) may have larger loops than those shown as well. Again, this device is situated in its secondary form so that the remainder (126) of any element attached formerly joint (104) after dissolution by electrolysis of joint (104), will not extend into the feeder vessel for this aneurysm. This retainer assembly (120) may be used to help close an aneurysm which is of substantial length but nominal width.
FIGS. 3A and 3B show still another variation of the inventive device (140). This variation shows one internal array member (142), although multiple array members may be used. In addition, FIGS. 3A and 3B show a number of external array members (144) which are intended to remain outside of the aneurysm when the aneurysm is deployed. These exterior or outer array members (144) are of the same general makeup and material as those shown in the earlier discussed Figures.
Although the overall configuration of this device (140) as shown in FIGS. 3A and 3B may be indented at the top in the same manner as the variations shown in FIGS. 1A, 1B, 2A, and 2B, this neck configuration is shown for purposes of completing the variations of this invention. The exterior array members (144) and the interior array member (142) may be attached to core wire (150) via a ferrule (146) perhaps by crimping or perhaps by welding the devices components together. An electrolytic joint (148) on core wire (150) is also shown. This variation of the invention is less desirable because of the possibility that the ferrule member (146) can be present in the flowing artery.
FIGS. 4A and 4B show another variation of the inventive device (160) having another number of exterior array members (162). It should be noted out that in some instances where the back wall of the aneurysm is determined to be especially weak and the neck of the aneurysm is considered to be the strongest retention point, that device such as is shown in FIGS. 3A, 3B, 4A, and 4B is quite useful. The presence of a single loop array element (164) within the aneurysm may be of benefit.
FIGS. 5A and 5B show a very simple variation (170) of the inventive device. This variation is a simple pair of array members (172) to be placed within the aneurysm. It too has a joining element (174) which may be the site from which interior elements (172) extend. The core wire (176) extends inward from the joining element (174) much as in the other arrangements discussed above.
FIGS. 6A and 6B show an very simple variation (180) of the inventive device. In this variation (180), the array elements (182) extend away from the region of the joint (184) and perhaps the joining element (186) and do not form a loop extending to the bottom of the aneurysm. This device is shown as having a small surface coil (discussed in more detail with regard to FIG. 10 below). In this variation, it may be typical that the ends of the array arms (182) farthest away from joint (184) form the contact regions with the aneurysm wall and therefore provide stability to this retainer device (180). That is to say that unlike the retainers discussed above, wherein the retainer is kept from movement by contact with multiple sites inside the aneurysm, this device may merely contact the farther-most walls of that aneurysm.
FIGS. 7A and 7B show another variation of, generally, both features of the FIG. 6A and 6B device as well as those shown in FIGS. 1A, 1B, 2A, and 2B. That is to say that the inventive device (190) utilizes loops as array members (192) which may extend to the bottom of the aneurysm. The joint for electrolytic dissolution (194) is recessed into the proximal end of the device (190). The upper portions of the array wires (192) are covered with a radio-opaque wrap (196).
It should be understood that the secondary shapes of the devices shown in FIGS. 1A through 7B are secondary shapes which occur when the retainer device is placed in the open air--that is to say not within aneurysm. Any placement of these devices in a human body will likely cause the secondary shape to distort. The shape which these devices actually take within an aneurysm, although preferably those shown in the drawings noted above, may not be as depicted.
FIG. 8 shows a close-up partial sectional view of desirable electrolytic joint configuration. In FIG. 8, the core wire (200) has over it, a plastic sleeve (202) which is cut at a bias or angle (204). The electrolytic joint (206) is small, discrete area which concentrates the flow of current into that area so to accelerate the dissolution of that joint. Preferably the region just proximal of the joint (208) is also covered with an insulator. Electrolytic joint (206) is placed as far distal as is reasonably possible during assembly so to prevent jagged edges and points after dissolution. In this variation, the joining block (210) is a plastic joint into which both the element (212)--distal to joint (206)--is embedded. Array members (214) are also shown and they are, as well, embedded in plastic junction member (210). This arrangement may provide some benefit, in that when an electric current is applied to core wire (200), there is no tendency for the current to flow into the array elements (214) because they are insulated by junction block (210). This is believed to accelerate the dissolution of joint (206).
FIG. 9 shows another close-up partial sectional view of the distal end of core wire (200) with joint (206) and proximal covering (208). The major difference between the variation shown in FIG. 8 and that shown in FIG. 9 is that the array members (214) are crimped onto distal member (212), using a ferrule (220). Such a ferrule (220) may simply mechanically attach array members (214) to core wire (200) or additional joining arrangements, e.g., welding or the like may be employed. Although soldering is not typically desirable because of the potential creation of a ragged joint on the proximal end of distal element (212), in some circumstances it may be permissible to solder it as well.
FIG. 10 shows a partial cut-away of an array arm (220) having an interior wire (222) and a radio-opaque coil (224) wrapped about its exterior. Exterior wire (224) may also be an exterior ribbon or the like, if such is a more pleasing variation to the designer using the teachings of this invention. Coil (224) is merely a radio-opacifier for the overall device (220).
This device may be deployed in the following manner. FIG. 11A shows a berry aneurysm (200) emanating from the wall of an artery (202). A catheter (204) is shown having radio-opaque band (206) at its distal end. The distal end of catheter (204) extends into the mouth (208) of the aneurysm (200). FIG. 11B shows a retainer device (212) having a shape similar to those discussed above. This variation of the inventive retainer (212) has interior array members (214) and exterior array members (216). It should be also noted that the exterior array members (216) are exterior to the aneurysm (200) and the remaining array members (214) are interior to aneurysm (200). It should probably be apparent that the various array members should not pinch the aneurysm in any very meaningful or deleterious way, lest some type of rupture occur.
In FIG. 11C, it can be seen that the voltage has been applied to core wire (218), and the electrolytic joint has been dissolved. The core wire (218) is then withdrawn from catheter (204) and discarded. It may be also seen in FIG. 11C that the region of the joint adjacent the retainer device (212) is recessed out of the flow of artery (202).
In FIG. 11D, catheter (204) has been re-introduced into the neck of aneurysm (200) and a number of vaso-occlusive devices--in this case, coils (220)--have been introduced into the volume formed by retainer assembly (212).
FIG. 11E show the withdrawal of catheter (204) from the feed vessel with the implantation of vaso-occlusive coils (220) and their stabilizing retainer (212) complete.
Many alterations and modifications may be made by those of ordinary skill in this art, without departing from the spirit and scope of this invention. The illustrated embodiments have been shown on for purposes of clarity and the example should not be taken as limiting the invention as defined in the following claims, which are intended to include all equivalents, whether now or later devised.
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This is a device for bridging the neck of either a wide-necked or narrow-necked aneurysm in the vasculature. In general, it is a device used to stabilize the presence of vaso-occlusive devices (such as helically wound coils) in the aneurysm. The device preferably is delivered by a core wire which terminates in an electrolytically severable joint. The core wire will often be insulated. The retainer assembly itself is also attached to the electrolytic joint and typically has a number of array elements which are intended to be resident within the aneurysm after the device is deployed from the distal end of a catheter. After deployment of this retainer, the aneurysm is at least partially filled with a vaso-occlusive device such as helically wound coils.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to an ethylene polymer cross linking composition capable of enhancing the degree with which an ethylene polymer is cross linked by application of heat, a method for the cross linking of an ethylene polymer by the use of the composition, and an electric power cable provided with a resinous layer of a cross linked-polymer produced by the method mentioned above.
This invention further relates to an ethylene polymer cross linking-composition which is in a liquid state at normal room temperature, manifests low volatility, and is stable for a long time.
Prior Art Statement
Heretofore, it has been known that in the production of a shaped article of a cross linked ethylene polymer using an organic peroxide as a cross linking agent, an increase in the cross linking degree can be attained by using the cross linking agent in an increased amount or by using the cross linking agent in combination with a cross linking auxiliary.
As a cross linking auxiliary, triallyl isocyanurate (TAIC) is mentioned in "Friends to Polymers", Vol. 18, No. 6, page 373 (1981). Such cross linking auxiliaries as divinylbenzene are mentioned in "I. & E. C Product Research and Development", Vol. 2, No. 3, page 202 (1963). Such vinyl compounds as α-methyl styrene and acrylic esters are cited as examples of the cross linking auxiliary in Japanese Patent Publication No. SHO 54-8500.
Rubber-plastic insulated electric power cable (hereinafter referred to simply as "electric power cable") generally comprises a conductor core and a semiconductive layer and an insulating layer enclosing the core. These layers are each formed by preparing a resin composition using as a basis thereof a polyethylene resin incorporating a cross linking agent therein, extruding the resin composition through an extruding device around the outer periphery of the conductor and coating the conductor with the extruded resin composition, and superheating the formed coat thereby cross linking the base resin.
As the cross linking agent for polyethylene, dicumyl peroxide (DCP) is prevalently used. Since this substance is solid (melting point 38°-40° C.) at normal room temperature, it is liable to occlude foreign matter while it is being handled and the foreign matter occluded therein is not easily discovered. Mixing the ethylene polymer and the DCP requires use of an extruding device, for example. For the DCP to be fed at a fixed rate to the extruding device, it must be melted by heating in advance of the feeding. Use of DCP therefore adds to the number of operational steps and requires considerable attention to operational safety.
The electric power cable is produced, for example, by a method which comprises preparing a mixture of molten resin with a cross linking agent which is used alone or in combination with an antioxidant and other additives, directly injecting the mixture into an extruding device, and coating a conductor core with an extruded strip of the mixture. In this case, the cross linking agent is required to be liquid at normal room temperature.
For the solution of this problem, cross linking quality organic peroxides which are liquid at normal room temperature have been proposed. Japanese Patent Publication No. HEI 2-31106, for example, discloses an organic peroxide mixture comprising 25 to 10% by weight of bis(α-t-butyl peroxyisopropyl)benzene and 75 to 90% by weight of isopropyl cumyl-t-butyl peroxide. Japanese Patent Public Disclosure No. SHO 54-132664 discloses an alkyl group-substituted dicumyl peroxide.
Such cross linking auxiliaries as TAIC disclosed in "Friends to Polymers", Vol. 18, No. 6, page 373 and divinylbenzene disclosed in "I. & E. C Product Research and Development", Vol. 1, No. 3, page 202 are capable of independent polymerization by themselves. When such a cross linking auxiliary is caused to coexist with an organic peroxide as a cross linking agent or when the cross linking auxiliary and the cross linking agent are simultaneously mixed with and dispersed in a polymer, the cross linking auxiliary partly polymerizes. To avoid this polymerization, the cross linking auxiliary and the cross linking agent must be mixed and dispersed separately of each other or they must be mixed and dispersed at a relatively low temperature. If the temperature is low, however, the polymer manifests high viscosity and the dispersion consumes a long time. The method disclosed in Japanese Patent Publication No. SHO 54-8500 is effective in preventing the polymer from scorching but not effective in enhancing the degree of cross linking. The α-methyl styrene and acrylic esters have small molecular weights and, therefore, have high vapor pressures. They therefore volatilize when they are kneaded with an ethylene polymer or when the composition produced by the mixture with the ethylene polymer is stored. This volatilization causes inconsistent quality of the produced cross linked polymer.
The polymers produced by using the organic peroxides taught by Japanese Patent Publication No. HEI 2-31106 and Japanese Patent Public Disclosure No. SHO 54-132644 have a disadvantage in that their cross linking degrees are lower than those of the polymers produced by using dicumyl peroxide, the most typical cross linking peroxide. As regards organic peroxides which are liquid at normal room temperature, organic peroxides having still lower melting points than the organic peroxides taught by Japanese Patent Publication No. HEI 2-31106 and Japanese Patent Public Disclosure No. SHO 54-132644 prove desirable for use during the winter. These organic peroxides are required to assume a liquid state at relatively low temperatures and manifest low vapor pressures.
The electric power cable will now be described. When the electric power cable is provided with such resinous layers as an insulating layer and a semiconducting layer, these resinous layers are apt to suffer scorching or inclusion of minute amber colored particles on account of the cross linking agent which is used in their formation. Further, during the formation of these resinous layers, they are liable to liberate a gas as a product of the decomposition of the cross linking agent or give rise to water trees. A practicable method which is capable of forming these resinous layers without inducing the problems mentioned above has therefore been desired.
SUMMARY OF THE INVENTION
Through an extended study of the drawbacks of the prior art, the inventors developed a cross linking composition for an ethylene polymer which is free from the problems mentioned above. This invention has been perfected as a result.
To be specific, this invention is directed to an ethylene polymer cross linking composition which comprises an organic peroxide as a cross linking agent and a compound represented by the following formula: ##STR2## (wherein R stands for a hydrogen atom or an alkyl group of 1 to 9 carbon atoms and n is an integer of 2 or 3), a method for cross linking an ethylene polymer by treating this ethylene polymer with the ethylene polymer-cross linking composition mentioned above, and an electric power cable consisting essentially of a conductor and at least two resinous layers coating the conductor, at least one of the two resinous layers being formed of a cross linked ethylene polymer cross linked by the method described above.
The above and other features of the invention will become apparent from the following description made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a diagram showing the time-course changes in the magnitude of torque found in a heating test performed on cross linked polyethylene samples obtained in Example 1 and Comparative Experiment 1.
FIG. 2 is a diagram showing the relation between the percentage composition of a ternary composition of DCP, IPC, and MDIB and the temperature of precipitation of crystals.
FIG. 3 is a diagram showing the relation between the percentage composition of a ternary composition of DCP, BPC, and MDIB and the temperature of precipitation of crystals.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The compounds which are represented by the formula (I) include o-diisopropenyl benzene, m-diisopropenyl benzene, p-diisopropenyl benzene, 1,2,4-triisopropenyl benzene, 1,3,5-triisopropenyl benzene, 3-isopropyl-o-diisopropenyl benzene, 4-isopropyl-o-diisopropenyl benzene, 4-isopropyl-m-diisopropenyl benzene, 5-isopropyl-m-diisopropenyl benzene, 2-isopropyl-p-diisopropenyl benzene, and mixtures thereof, for example (hereinafter referred to collectively as "poly-IPBs). Among the poly-IPBs cited above, the m-diisopropenyl benzene proves particularly desirable because it is liquid at normal room temperature and markedly effective in enhancing the cross linking degree of polymer.
As concrete examples of the organic peroxide to be used in this invention, dialkyl peroxides such as dicumyl peroxide, t-butylcumyl peroxide, 2,5-bis(t-butyl peroxy)2,5-dimethyl hexane, 2,5-bis(t-butyl peroxy) 2,5-dimethyl hexyne-3, di-t-butyl peroxide, isopropylcumyl-t-butyl peroxide, and bis(α-t-butyl peroxyisopropyl)benzene, peroxy ketals such as 1,1-bis(t-butyl peroxy) cyclohexane, 1,1-bis(t-butyl peroxy) 3,3,5-trimethyl cyclohexane, 1,1-bis(t-butyl peroxy) cyclododecane, n-butyl-4,4-bis(t-butyl peroxy) valerate, ethyl-3,3-bis(t-butyl peroxy) butyrate, and 3,3,6,6,9,9-hexamethyl-1,2,4,5-tetraoxy cyclononane, and peroxy esters such as bis(t-butyl peroxy) isophthalate, t-butyl peroxy benzoate, and t-butyl peroxy acetate may be cited.
Among the organic peroxides cited above, dicumyl peroxide (hereinafter referred to as "DCP") and bis(α-t-butyl peroxy isopropyl) benzene prove particularly desirable because they exhibit high efficiency in cross linking a polymer and manifest only very low volatility. They are not easily handled because they are solid at 25° C. Compositions which allow precipitation of crystals at temperatures not exceeding 25° C. cross link a polymer with high efficiency, and manifest only low volatility can be produced by mixing these organic peroxides with poly-IPBs or mixing them with isopropyl cumyl-t-butyl peroxide which is liquid at -10° C.
The isopropyl cumyl-t-butyl peroxide proves particularly desirable as a cross linking agent for the formation of resinous layers as in an electric power cable because it has a high thermal decomposition temperature as compared with the DCP which has been heretofore used most widely as a cross linking agent, exhibits only low susceptibility to scorching, assumes a liquid state at normal room temperature, has relatively low volatility, and does not produce a harmful decomposition product.
Except for bis(α-butyl peroxyisopropyl) benzene, 3,3,6,6,9,9-hexamethyl-1,2,4,5-tetraoxy cyclononane, bis(6-t-butyl peroxy) isophthalate, t-butyl peroxy benzoate, and DCP, the peroxides cited above are liquid at -10° C.
The ethylene polymers which are usable for the cross linking aimed at by this invention include polyethylene, ethylene-propylene copolymer (EPR), ethylene-butene copolymer, ethylene-pentene copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-propylene-diene copolymer (EPDM), chlorinated polyethylene, ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer (EGMA), and ethylene-acrylonitrile copolymer, for example. Polyethylene, EPR, EVA, EEA, and EGMA are superior to the other ethylene polymers cited above in point of the effect in improving the cross linking degree.
In the composition of this invention, the mixing ratio of the organic peroxide to the poly-IPB is generally in the range between 1:0.02 and 1:3 by weight. The composition does not exhibit sufficient effect in improving the cross linking degree if the mixing ratio of the poly-IPB to the organic peroxide is less than 1:0.02. The cross linking degree tends to decline if the mixing ratio exceeds 1:3. The particularly desirable range of this mixing ratio is between 1:0.1 and 1:1.
The amount of the organic peroxide and that of the poly-IPB to be used for cross linking the ethylene polymer are desired to be respectively in the range between 0.3 and 5 parts by weight and the range between 0.1 and 3 parts by weight, based on 100 parts by weight of the ethylene polymer. The effect in improving the cross linking degree of the polymer is not sufficient if the amount of the organic peroxide is less than 0.3 part by weight. The cross linking degree increases excessively and the produced polymer becomes brittle if this amount exceeds 5 parts by weight. The cross linking degree is not sufficient if the amount of the poly-IPB is less than 0.1 part by weight. The cross linking degree is liable to be unduly low if this amount exceeds 3 parts by weight.
When the polymer is cross linked with the composition of this invention, independent addition of the components of this composition to the polymer is as effective as when the composition of this invention is used in its whole form in the polymer.
When the cross linking of an ethylene polymer is effected by the use of the composition of this invention, various additives such as, for example, antioxidant, pigment, ultraviolet stabilizer, filler, plasticizer, slip additive, and cross linking auxiliary which are generally used in cross linking can be added to the composition.
The antioxidants which are effectively usable herein include phenol compounds such as 4,4'thiobis(3-methyl-6-t-butyl phenol), 2,5-di-t-butyl hydroquinone, and 2,6-di-t-butyl-p-cresol, phosphorus compounds, and sulfur compounds such as bis(2-methyl-4-(3-n-alkyl thiopropioniloxy)-5-t-butylphenyl) sulfide, 2,2'-thiodiethylene bis-[3-(3,5-di-t-butyl-4-hydroxy phenyl) propionate], dilauryl thiopropionate, and distearyl thiopropionate, for example.
The amount of the antioxidant to be incorporated in the composition is generally in the range between 0.05 and 1.0 part by weight, based on 100 parts by weight of the ethylene polymer.
The antioxidant is inherently capable of inhibiting the reaction of cross linking. The composition of this invention accomplishes the effect of improving the cross linking degree and precluding scorching even in the presence of this antioxidant.
When the composition of this invention is used in cross linking the polymer, the cross linking temperature is generally in the range between 110° and 220° C. For ensuring a proper cross linking time, the desirable range of the cross linking temperature is between 130° and 200° C.
When the electric power cable of this invention comprises a conductor core and at least two resinous layers differing in function and encircling the conductor, at least one of these resinous layers consists essentially of an ethylene polymer cross linked with the cross linking composition of this invention.
The effects of this invention will now be described.
(1) When the polymer is cross linked by the use of the composition of this invention which combines an organic peroxide with a compound represented by the formula (I), the cross linking degree of the polymer is improved and the time up to the start of scorching is prolonged as compared with the cross linking involving sole use of the organic peroxide.
(2) No polymerization occurs when a polymerizing auxiliary is used as mixed with the polymer which is subjected to the cross linking, for example.
(3) When an organic peroxide which is solid at normal room temperature, specifically at 25° C., is used in the composition of this invention, the produced composition is liquid at normal room temperature or at lower temperatures.
(4) The composition of this invention possesses high stability against storage, exhibits small vapor pressure, and volatilizes at a slow speed. Further, in the cross linking to be effected by the use of the composition of this invention, the effects of this invention enumerated above can be attained even in the presence of an antioxidant.
(5) The resinous layers in the electric power cable of this invention does not suffer scorching and manifests a high cross linking degree (gel ratio). The electric power cable which is provided with these resinous layers, therefore, enjoys highly satisfactory electrical properties (AC breakdown strength). Since the amount of the cross linking agent required to be used effectively in the formation of the resinous layers in this invention is small as compared with that which is required in the conventional method, the amounts of gas and water trees liberated in consequence of the decomposition of the cross linking agent are proportionately small.
This invention will now be described more specifically below with reference to working examples and comparative experiments. The abbreviations of organic peroxides and additives to be used hereinafter denote the following compounds.
DCP: Dicumyl peroxide (purity 99%; marketed by Nippon Oil & Fats Co., Ltd. as "Percumyl D")
BCP: t-Butyl cumyl peroxide (purity 92%; marketed by Nippon Oil Fats & Co., Ltd. as "Perbutyl C")
DBC: m-Bis(α-t-butyl peroxyisopropyl) benzene (purity 99%; marketed by Nippon Oil & Fats Co., Ltd. as "Perbutyl P")
IPC: Isopropyl cumyl-t-butyl peroxide (m/p 60/40 and purity 94%; marketed by Nippon Oil & Fats Co., Ltd. as "Perbutyl IPC")
25B: 2,5-Bis(t-butyl peroxy)-2,5-dimethyl hexane (purity 99%; marketed by Nippon Oil & Fats Co., Ltd. as "Perhexa 25B")
25Y: 2,5-Bis(t-butyl peroxy)-2,5-dimethylhexine-3 (purity 90%; marketed by Nippon Oil & Fats Co., Ltd. as "Perhexine 25B")
3M: 1,1-Bis(t-butyl peroxy)-3,3,5-trimethyl cyclohexane (purity 92%; marketed by Nippon Oil & Fats Co., Ltd. as "Perhexa 3M")
IPCC: Isopropyl cumylcumyl peroxide (synthesized by condensing isopropyl cumyl alcohol (m/p=60/40) and cumene hydroperoxide in a ratio of 1/1 (mol) in the presence of a perchloric acid catalyst)
MDIB: m-Diisopropenyl benzene
XDIB: Diisopropenyl benzene (o-/m-/p-=3/67/30)
TIB: 1,2,4-Triisopropenyl benzene
RDIB: 4-Isopropyl-o-diisopropenyl benzene/4-isopropyl-m-diisopropenyl benzene/2-isopropyl-p-diisopropenyl benzene=1/1/1
αMS: α-Methyl styrene
DVB: p-Divinyl benzene
TBP: 4,4'-Thiobis(3-methyl-6-t-butyl phenol)
OMA: 2-Ethylhexyl methacrylate
TAIC: Triallyl isocyanurate
EXAMPLE 1
A composition was obtained by mixing 500 g of low-density polyethylene [marketed by Nippon Unicar Co., Ltd. as "Polyethylene (NUC-9025)"] with 12.5 g of DCP and g of MDIB. This composition was kneaded by the use of heating rolls at about 110° C. for about 20 minutes. The produced composition was homogeneous and showed no abnormal surface condition. It was subjected to a heating test with a testing instrument (marketed by Toyo-Boldwin K.K. as "JSR Curastometer III"). The torque as a function of the heating time obtained at 180° C. and 145° C. in this heating test are shown by the curves 1 and 2 in FIG. 1. In the diagram, the maximum torque at 180° C. is found to be 5.24 kgf.cm.
The scorching time at 145° C. was determined as follows.
The time required for the torque to rise from the minimum torque at 145° C. by of 10% of the maximum torque at 180° C. was clocked and recorded as the scorching time. The results are shown in Table 1.
COMPARATIVE EXPERIMENT 1
The procedure of Example 1 was repeated, except that the use of MDIB was omitted. The changes in torque as a function of the heating time are shown by the curves 3 and 4 in FIG. 1. The results obtained are shown in Table 1.
It will be noted from FIG. 1 that compared with Comparative Experiment 1, in Example 1 the cross linking speed and cross linking degree were higher at the high temperature (180° C.) and the cross linking speed was lower at the low temperature (145° C.). This fact indicates that Example 1 improved the cross linking degree and prolonged the time before start of scorching.
COMPARATIVE EXPERIMENT 2
The procedure of Example 1 was repeated, except that 13 g of IPCC was used in place of DCP and the use of MDIB was omitted. The results are shown in Table 1.
COMPARATIVE EXPERIMENT 3
The procedure of Example 1 was repeated, except that 5 g of DVB was used in place of MDIB. The results are shown in Table 1. The surface of the composition obtained after the kneading with heating rolls showed spots presumed attributable to polymerization of DVB.
COMPARATIVE EXPERIMENT 4
The procedure of Example 1 was repeated, except that 5 g of TAIC was used in place of MDIB. The results are shown in Table 1. The surface of the composition obtained after the kneading with heating rollers showed spots presumed attributable to polymerization of TAIC.
It will be noted from the results of Example 1 and Comparative Experiments 3 and 4 that the composition of this invention did not undergo a polymerization reaction during the kneading operation.
EXAMPLES 2 TO 19 AND COMPARATIVE EXPERIMENTS 5 TO 22
The procedure of Example 1 was repeated, except that the percentage composition of the composition was varied as shown in Table 1. The results are shown in Table 1.
TABLE 1__________________________________________________________________________ MaximumEx- Compound of torque at Comparative Maximumample Peroxide formula (I) TBP B/A Time* 180° C. Experiment Peroxide Additive Time* torqueNo. (A) (g) (B) (g) (b) (g) (min) (kgf · cm) No. (g) (g) (min) (kgf · cm)__________________________________________________________________________ 1 DCP 12.5 MDIB 5.0 0.40 12.2 5.24 1 DCP 12.5 5 3.10 2 DCP 12.5 XDIB 5.0 0.40 12.5 5.20 2 IPCC 13 8 2.51 3 DCP 12.5 RDIB 5.0 0.40 10.4 4.61 3 DCP 12.5 DVB 5.0 3.5 3.88 4 DCP 12.5 TIB 5.0 0.40 9.9 5.96 4 DCP 12.5 TAIC 5.0 2.6 4.50 5 DCP 8.7 MDIB 3.8 0.44 10.7 3.50 5 DCP 12.5 OMA 5.0 9.3 2.68 6 DCP 12.5 αMS 5.0 6 3.25 6 DCP 12.5 MDIB 2.5 1.0 0.20 11 3.62 7 DCP 12.5 TBP 1.0 10 2.78 8 DCP 12.5 αMS 2.5 13 2.92 TBP 1.0 7 DCP 12.5 MDIB 5.0 1.0 0.40 16 4.49 9 DCP 12.5 αMS 5.0 16 2.92 TBP 1.0 8 DCP 12.5 MDIB 7.5 1.0 0.60 17 4.31 10 DCP 12.5 αMS 7.5 18 2.30 9 DCP 12.5 MDIB 5.0 1.0 0.40 16 4.96 TBP 1.0 (2.5)10 DCP 9.3 MDIB 1.6 0.17 8.5 3.40 11 DCP 10.6 5.6 2.90 IPC 1.6 IPC 1.911 DCP 6.3 MDIB 5.0 1.0 0.42 25 4.43 12 DCP 6.3 TBP 1.0 16.5 2.36 IPC 5.7 IPC 5.712 IPC 11.5 MDIB 2.5 1.0 0.22 22 2.45 13 IPC 11.5 TBP 1.0 22 1.43 14 IPC 11.5 αMS 2.5 24 1.8613 IPC 11.5 MDIB 5.0 1.0 0.44 25 3.09 15 IPC 11.5 αMS 5.0 21 1.69 TBP 1.014 DCP 6.3 MDIB 5.0 1.0 0.43 26 4.20 16 DCP 6.3 TBP 1.0 16.5 2.67 BCP 5.3 BCP 5.315 DBC 8.0 MDIB 2.5 1.0 0.31 28 4.25 17 DBC 8.0 TBP 1.0 27 3.80 18 DBC 8.0 αMS 2.5 29 3.28 TBP 1.016 DBC 4.0 MDIB 5.0 1.0 0.43 36 4.43 19 DBC 4.0 TBP 1.0 24.5 2.50 IPC 5.7 IPC 5.717 DBC 8.0 MDIB 5.0 1.0 0.82 31 4.29 20 DBC 8.0 α MS 5.0 32 3.79 TBP 1.018 DBC 4.0 MDIB 5.0 1.0 0.54 46 3.68 21 DBC 8.0 TBP 1.0 30 2.42 BCP 5.3 BCP 5.319 DBC 2.0 MDIB 2.5 0.25 12 2.67 22 DBC 2.0 8 2.33 IPC 8.0 IPC 8.0__________________________________________________________________________ The numeral given in brackets in the "TBP" column indicates the amount of TAIC used additionally. *The time before the start of scorching at 145° C.
The contents of Table 1 will now be explained.
RE; EXAMPLES 1 TO 5 AND COMPARATIVE EXPERIMENT 1
These experiments demonstrate that the combined use of a compound of the formula (I) with an organic peroxide improves the maximum torque and prolongs the time before the start of scorching.
RE: COMPARATIVE EXPERIMENTS 3 AND 4
These experiments demonstrate that the omission of the use of a compound of the formula (I) and the use of a known cross linking auxiliary results in improving the cross linking degree but shortens the time before the start of scorching.
RE: COMPARATIVE EXPERIMENTS 5 AND 6
These experiments demonstrate that the combined use of OMA and αMS brings about a slight increase in the time before the start of scorching but no discernible effect on the maximum torque and that the OMA causes a decrease in the maximum torque.
RE: EXAMPLES 6, 7, 8, 12, 13, 15 AND 17 AND COMPARATIVE EXPERIMENTS 7 TO 10, 13 TO 15, 17, 18, AND 20
These experiments demonstrate that the combined use of an organic peroxide with MDIB prevents the effect of treatment from declining in the presence of an antioxidant (TBP) as an additive.
RE: EXAMPLES 10, 11, 14, 16, 18, AND 19 AND COMPARATIVE EXPERIMENTS 11, 12, 16, 19, 21, AND 22
These experiments demonstrate that the combined use of a plurality of organic peroxides has no influence on the effect of the treatment.
RE: EXAMPLES 7 AND 9
These experiments demonstrate that even the combined use of MDIB with TAIC, which is a conventional cross linking auxiliary, is effective in improving the cross linking degree and prolonging the time before the start of scorching.
RE: EXAMPLES 1 AND 19 AND COMPARATIVE EXPERIMENTS 2 AND 22
These experiments demonstrate that the conventional liquid peroxides are inferior to the peroxides of this invention in point of maximum torque and the time before the start of scorching.
EXAMPLE 20
A composition was obtained by mixing 500 g of high-density polyethylene (marketed by Ace Polymer K.K. as "HDF6080V") with 12.5 g of DCP, 5.0 g of MDIB (MDIB/DCP=0.40), and 1.0 g of TBP. This composition was kneaded with heating rolls at about 130° C. for about 20 minutes. The kneaded composition was tested in the same manner as in Example 1. As a result, the maximum torque at 180° C. was found to be 5.65 kgf.cm and the time before the start of scorching at 145° C. to be 9.3 minutes.
COMPARATIVE EXPERIMENT 23
The procedure of Example 20 was repeated, except that the use of MDIB was omitted. As a result, the maximum torque at 180° C. was found to be 3.50 kgf.cm and the time before the start of scorching at 145° C. to be 8.8 minutes.
Comparison of the results of Example 20 and Comparative Experiment 23 clearly reveals that high density polyethylene is as effective in improving the maximum torque and prolonging the time before the start of scorching as low density polyethylene when the polyethylene is used in combination with MDIB.
EXAMPLE 21
A composition was produced by mixing 500 g of the same polyethylene as used in Example 1 with 7.5 g of 25Y, 5.0 g of MDIB (MDIB/25Y=0.66), and 1.0 g of TBP. This composition was kneaded with heating rolls at about 110° C. for about 20 minutes. The kneaded composition was tested by the use of the Curastometer. As a result, the maximum torque at 200° C. was found to be 2.78 kgf.cm and the time before the start of scorching at 160° C. to be 32 minutes.
COMPARATIVE EXPERIMENT 24
The procedure of Example 21 was repeated, except that the use of MDIB was omitted. As a result, the maximum torque at 200° C. was found to be 2.17 kgf.cm and the time before the start of scorching at 160° C. to be 26 minutes.
Comparison of the results of Example 21 and Comparative Experiment 24 reveals that even at relatively high temperature, the use of MDIB is effective in improving the maximum torque and prolonging the time before the start of scorching.
EXAMPLE 22
A composition was obtained by mixing 500 g of an ethylene-propylene copolymer (propylene content 22%; marketed by Japan Synthetic Rubber Co., Ltd. as "JSR-EP912P") with 7.5 g of 25Y, and 2.5 g of MDIB (MDIB/25Y=0.33). This composition was kneaded by the use of heating rolls at about 60° C. for about 20 minutes. The kneaded composition was tested with the Curastometer. The maximum torque at 200° C. was found to be 10.47 kgf.cm and the time before the start of scorching to be 16 minutes.
COMPARATIVE EXPERIMENT 25
The procedure of Example 22 was repeated, except that the use of MDIB was omitted. The maximum torque at 200° C. was found to be 7.28 kgf.cm and the time before the start of scorching at 160° C. to be 10 minutes.
COMPARATIVE EXPERIMENT 26
The procedure of Example 22 was repeated, except that 2.5 g of αMS was used in place of MDIB. The maximum torque at 200° C. was found to be 8.15 kgf.cm and the time before the start of scorching at 160° C. to be 16 minutes.
EXAMPLE 23
A composition was obtained by mixing 500 g of an ethylene-vinyl acetate copolymer (vinyl acetate content 12% by weight; marketed by Mitsubishi Petro-Chemical Co., Ltd. as "EVA303E") with 7.5 g of 25B and 2.5 g of MDIB (MDIB/25B=0.33). This composition was kneaded by the use of heating rolls at about 80° C. for about 20 minutes. The kneaded composition was tested with the Curastometer. The maximum torque at 180° C. was found to be 6.14 kgf.cm and the time before the start of scorching at 145° C. to be 10 minutes.
COMPARATIVE EXPERIMENT 27
The procedure of Example 23 was repeated, except that the use of MDIB was omitted. The maximum torque at 180° C. was found to be 4.66 kgf.cm and the time before the start of scorching at 145° C. to be 6 minutes.
COMPARATIVE EXPERIMENT 28
The procedure of Example 23 was repeated, except that 2.5 g of n-octyl acrylate was used in place of MDIB. The maximum torque at 180° C. was found to be 3.92 kgf.cm and the time before the start of scorching at 145° C. to be 9 minutes.
EXAMPLE 24
A composition was obtained by mixing 500 g of an ethylene-vinyl acetate copolymer (marketed by Mitsubishi Petro-Chemical Co., Ltd. as "EVA303E") with 12.5 g of 3M, and 2.5 g of MDIB (MDIB/3M=0.20). This composition was kneaded by the use of heating rolls at about 80° C. for about 20 minutes. The kneaded composition was tested with the Curastometer. The maximum torque at 145° C. was found to be 3.49 kgf.cm and the time before the start of scorching at 120° C. to be 12 minutes.
COMPARATIVE EXPERIMENT 29
The procedure of Example 24 was repeated, except that the use of MDIB was omitted. The maximum torque at 145° C. was found to be 2.89 kgf.cm and the time before the start of scorching at 120° C. to be 7 minutes.
EXAMPLES 25 TO 30
Compositions were obtained by mixing different organic peroxides with MDIB or XDIB as compounds represented by the formula (I) at the different mixing ratios indicated in Table 2. Each composition thus produced was placed in a test tube 20 mm in inside diameter and stirred and cooled at a temperature decreasing rate of 0.5° C. per minute to find the temperature at which the composition began to precipitate crystals. The results are shown in Table 2.
The composition was stored in a constant temperature bath at 30° C. for one month. Then, it was assayed for contents of additives by gas chromatography to determine the polymerization ratios of the additives. A composition was produced by mixing 20 g of the composition with 1,000 g of low density polyethylene pellets (marketed by Nippon Unicar Co., Ltd. as "NUC-9025"). This composition was placed in a polyethylene bag 0.05 mm in wall thickness, sealed therein, and left standing at a temperature of about 15° C. for 30 days. The amount of the composition volatilized during the standing was determined from the change in weight. The results are shown in Table 2.
COMPARATIVE EXPERIMENTS 30 TO 35
Compositions were obtained using various organic peroxides either singly or in the form of a mixture of two or more members as indicated in Table 2. They were tested in the same manner as in Example 25. The results are shown in Table 2.
TABLE 2__________________________________________________________________________ Compound of Temperature Amount PolymerizationExamplePeroxide formula (I) of precipitation volatilized ratioNo. (A) (g) (B) (g) B/A (°C.) (%) (%)__________________________________________________________________________25 DCP 100 MDIB 43 0.43 20.4 4.5 0.026 DCP 100 MDIB 67 0.67 13.8 5.7 0.027 DCP 100 MDIB 100 1.00 6.7 7.1 0.028 DCP 100 XDIB 50 0.50 17.7 4.7 0.029 DCP 70 MDIB 30 0.30 9.6 3.3 0.0IPC 3030 DCP 85 MDIB 15 0.15 18.7 1.5 0.0IPC 15__________________________________________________________________________Comparative Temperature Amount PolymerizationExperiment Peroxide Additive of precipitation volatilized ratioNo. (A) (g) (g) (°C.) (%) (%)__________________________________________________________________________30 DCP 100 38.5 0.0 --31 DCP 100 TAIC 30 30 0.0 89.532 DCP 100 αMS 30 27 9.8 0.033 IPCC 100 23 0.0 --34 DCP 70 25.5 0.6 -- IPC 3035 DCP 85 32 0.3 -- IPC 15__________________________________________________________________________
It will be noted from Table 2 that the compositions conforming to this invention showed low temperatures for precipitation of crystals as compared with the compositions omitting the addition of MDIB. In Examples 25 to 30, there were obtained cross linked compositions which were liquid at temperatures not exceeding 20° C.
Further, small amounts of the compositions of Examples 25 to 30 volatilized, differently from the composition of Comparative Experiment 32.
EXAMPLES 31 AND 32
Compositions using DCP, IPC and MDIB, or DCP, BCP and MDIB were tested for temperature of crystal precipitation in the same manner as in Example 25. The results are shown in FIGS. 2 and 3.
It will be noted from FIGS. 2 and 3 that the composition using the combination of DCP and MDIB and possessing a solid state at 25° C. showed a decrease in the temperature for precipitation of crystals and that the additional incorporation therein of a liquid organic peroxide resulted in a further decrease in this temperature.
EXAMPLE 33 (PRODUCTION OF ELECTRIC POWER CABLE)
An electric power cable rated for 6 kV, having cross-sectional area of 38 mm 2 , and insulated with cross linked polyethylene was produced by coating a conductor with an inner semiconducting layer of a composition of ethylene vinyl acetate, acetylene black, IPC, and MDIB (100/60/0.5/0.2 by weight ratio) extruded by the use of an extruding device, then coated with an insulating layer of a composition of low-density polyethylene, IPC, MDIB, and TBP (100/2.5/1/0.2 by weight ratio) extruded at 145° C. by the use of an extruding device, further coated with an outer semiconducting layer of the same composition as used in the inner semiconducting layer and extruded in the same manner as above, and thereafter cross linking the compositions in the superposed layers at 200° C. for 5 minutes. The AC breakdown voltage of the so-produced electric power cable was 250 kV. When a sample cut from the cross linked insulating coat of this cable was observed under a microscope, it showed no sign of "scorch". The sample was extracted with xylene at 130° C. for 5 hours and the extract was tested for gel content. Thus, the gel content was found to be 93%.
COMPARATIVE EXPERIMENT 36
An electric power cable was produced and tested by following the procedure of Example 33, except that an insulating composition consisting of low-density polyethylene, DCP, and TBP (100/2.5/1/0.2 by weight ratio) was used in place of the composition consisting of low-density polyethylene, IPC, MDIB, and TBP. The AC breakdown voltage of the so-produced electric power cable was 210 kV. A sample of the insulating coat of this cable, on observation under a microscope, showed signs of "scorch". When the sample was extracted with xylene at 130° C. for 5 hours and the extract was tested for gel content, the gel content was found to be 88%.
It is clear from the results of Example 33 and Comparative Experiment 35 that the electric power cable of this invention did not scorch, manifested high cross linking degree, and exhibited improved electrical properties as compared with the conventional electric power cable.
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A composition for cross linking an ethylene polymer comprises an organic peroxide as a cross linking agent and a compound represented by the formula: ##STR1## wherein R stands for a hydrogen atom or one member selected from the class consisting of alkyl groups of 1 to 9 carbon atoms and n is an integer of 2 or 3. A method for cross linking the ethylene type polymer uses the composition mentioned above. An electric power cable comprises a core coated with resinous layers produced by the method described above.
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CROSS REFERENCE
[0001] This application is a divisional of U.S. Ser. No. 11/500,104 filed Aug. 7, 2006, which is a continuation-in-part of U.S. Ser. No. 10/924,270 filed Aug. 23, 2004, the disclosures of which are incorporated in their entireties for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The subject invention generally relates to a nozzle assembly for a kinetic spray system.
[0004] 2. Description of the Related Art
[0005] A nozzle assembly for a kinetic spray system typically comprises a mixing chamber for mixing a stream of powder particles under positive pressure with a flow of a heated gas. The mixing chamber is connected to a converging diverging deLaval type supersonic nozzle. The heated gas is also introduced into the mixing chamber under a positive pressure, which is set lower than the positive pressure of the stream of powder particles. In the mixing chamber, the flow of heated gas and the stream of powder particles mix together to form a gas/powder mixture. The gas powder mixture flows from the mixing chamber into the supersonic nozzle, where the powder particles are accelerated to a velocity between the range of 200 to 1,300 meters per second.
[0006] U.S. patent application Ser. No. 2005/0214474 A1 (the '474 application) discloses a de Laval type nozzle assembly for a kinetic spray system. The nozzle assembly includes a convergent portion defining an inlet and an outlet. The outlet is in spaced relationship relative to the inlet. A divergent portion defines an entrance and an exit, with the exit in spaced relationship relative to the entrance. A throat portion interconnects the outlet of the convergent portion and the entrance of the divergent portion. The convergent portion, the throat portion, and the divergent portion define a passage therethrough having a perimeter narrowing between the inlet and the outlet of the convergent portion, and expanding between the entrance and the exit of the divergent portion.
[0007] During operation of the nozzle assembly, such as the nozzle assembly disclosed in the '474 application, the particles exit the nozzle and adhere to a substrate placed opposite the nozzle assembly, provided that a critical velocity has been exceeded. The critical velocity of the powder particles is dependent upon its material composition and its size. Higher density particles generally need a higher velocity to adhere to the substrate. Additionally, it is more difficult to accelerate larger powder particles. Accordingly, the coating density and deposition efficiency of the particles can be very low with harder to spray powder particles. The velocity of the powder particles, upon exiting the nozzle assembly, varies inversely to the size and the density of the powder particles. Increasing the velocity of the flow of heated gas increases the velocity of the powder particles upon exiting the nozzle assembly. However, there is a limit to the achievable velocity of the flow of heated gas within the kinetic spray system. Thus, there is a need to improve the nozzle assembly to increase the velocity of the powder particles to improve adherence to the substrate of hard to spray powder particles having a high density and a larger size.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0008] The subject invention provides a nozzle assembly for a kinetic spray system. The nozzle assembly comprises a convergent portion defining an inlet and an outlet. The outlet is in spaced relationship relative to the inlet. A divergent portion defines an entrance and an exit, with the exit in spaced relationship relative to the entrance. A throat portion interconnects the outlet of the convergent portion and the entrance of the divergent portion. The convergent portion, the throat portion, and the divergent portion define a passage therethrough. The passage includes a perimeter narrowing between the inlet and the outlet of the convergent portion, and expanding between the entrance and the exit of the divergent portion. An extension portion further defines the passage and extends from the exit of the divergent portion to a distal end spaced a pre-determined length from the exit. The perimeter of the passage defined by the extension portion is at least equal to or greater than the perimeter of the passage defined by the exit of the divergent portion.
[0009] The subject invention also provides a method of coating a substrate with a powder applied by the kinetic spray system. The method comprises the steps of mixing the powder with a flow of heated gas; directing the flow of heated gas through the convergent portion, the throat portion, and the divergent portion of the nozzle assembly to accelerate the flow of heated gas and provide a drag force to act upon the powder to accelerate the powder; and passing the accelerated flow of heated gas and the powder through the extension portion of the nozzle assembly to provide additional time for the drag force of the flow of heated gas to act upon the powder to further accelerate the powder to a critical velocity.
[0010] Accordingly, the subject invention increases the overall length of the nozzle assembly while limiting an expansion ratio of the passage over the pre-determined length of the extension portion to avoid any negative effects that occur by merely extending the divergent portion. This increases the amount of time a stream of powder particles is exposed to a dragging force created by a flow of a heated gas through the nozzle assembly. This increased exposure of the stream of powder particles to the dragging force provides more time for the dragging force to accelerate the powder particles to an increased velocity not previously achievable. The increased velocity of the powder particles improves the ability of the kinetic spray system to adhere hard to spray materials such as high density and larger sized powder particles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
[0012] FIG. 1 is a schematic layout illustrating a kinetic spray system;
[0013] FIG. 2 is a cross sectional view of a nozzle for use in the kinetic spray system;
[0014] FIG. 3 is an enlarged cross sectional view of an extension portion of the nozzle;
[0015] FIG. 4 is an end view of the extension portion of the nozzle shown in FIG. 3 ;
[0016] FIG. 5 is an enlarged cross sectional view of an alternative embodiment of the extension portion of the nozzle;
[0017] FIG. 6 is an end view of the alternative embodiment of the extension portion of the nozzle shown in FIG. 5 ;
[0018] FIG. 7 is a cross sectional view of an alternative embodiment of a conditioning chamber for the nozzle;
[0019] FIG. 8 is a cross sectional view of an alternative embodiment of the nozzle showing an alternative method of injecting a powder into a high pressure gas flowing through the nozzle; and
[0020] FIG. 9 is an end view an alternative embodiment of the extension portion of the nozzle showing a circular cross section.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention comprises an improvement to the kinetic spray system and nozzle assembly 20 as generally described in U.S. Patent Application Ser. No. 2005/0214474 A1; U.S. Pat. Nos. 6,139,913 and 6,283,386; and the article by Van Steenkiste, et al. entitled “Kinetic Spray Coatings” published in Surface and Coatings Technology Volume III, Pages 62-72, Jan. 10, 1999. The disclosures of which are all herein incorporated by reference.
[0022] Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, a kinetic spray system is generally shown at 20 . Referring to FIG. 1 , the kinetic spray system 20 applies a coating of powder particles 22 to a substrate material 24 . A flow of heated gas suspends the powder particles 22 , which are then sprayed onto the substrate 24 at high velocities. As disclosed in U.S. Pat. No. 6,139,913 the substrate material 24 may be comprised of any of a wide variety of materials including a metal, an alloy, a plastic, a polymer, a ceramic, a wood, a semiconductor, or any combination and mixture of these materials. The powder particles 22 used in the kinetic spray system 20 may comprise any of the materials disclosed in U.S. Pat. Nos. 6,139,913 and 6,283,386 in addition to other known powder particles 22 . These powder particles 22 generally comprise a metal, an alloy, a ceramic, a polymer, a diamond, a metal coated ceramic, a semiconductor, or any combination and mixture of these materials. Preferably, the particles have an average nominal diameter between the ranges of 1 micron to 250 microns.
[0023] The kinetic spray system 20 includes an enclosure 26 in which a support table 28 or other support device is located. A mounting panel 30 is fixed to the support table 28 , and supports a work holder 32 . The work holder 32 is capable of movement in three dimensions and is able to support a suitable work piece. The work piece is formed from the substrate material 24 that is to be coated. The enclosure 26 includes surrounding walls defining at least one air inlet (not shown) and at least one air outlet 34 connected by a suitable exhaust conduit 36 to a dust collector (not shown). During operation of the kinetic spray system 20 the dust collector continually draws air from within the enclosure 26 , and collects any dust or particles contained in the air for subsequent disposal before exhausting the air.
[0024] The kinetic spray system 20 further includes a gas compressor 38 capable of supplying a flow of a gas at a pressure up to 3.4 MPa (500 psi) to a ballast tank 40 . Many different gases may be utilized in the kinetic spray system 20 including air, helium, argon, nitrogen, or some other noble gas. The ballast tank 40 is in fluid communication with a powder feeder 42 and a gas heater 44 through a system 20 of lines 46 . The gas heater 44 supplies a flow of heated gas, the heated main gas described below, to a nozzle assembly 48 . The powder feeder 42 mixes the powder particles 22 to be sprayed into a stream of unheated gas and supplies the mixture of unheated gas and powder particles 22 to a supplemental inlet line 50 to supply the nozzle assembly 48 with the powder particles 22 . A computer 52 controls the pressure of the gas supplied to the gas heater 44 and to the powder feeder 42 , and the temperature of the heated main gas exiting the gas heater 44 .
[0025] Referring to FIG. 2 , a main gas passage 54 connects the gas heater 44 to the nozzle assembly 48 . A premix chamber 56 is connected to the main gas passage 54 and directs the heated main gas through a flow straightener 58 and into a mixing chamber 60 . The mixing chamber 60 mixes the powder particles 22 into the flow of heated main gas to suspend the powder particles 22 in the heated main gas. Preferably, the mixing chamber 60 is disposed upstream of a conditioning chamber 62 (described below). A temperature of the heated main gas is monitored by a temperature thermocouple 64 in the main gas passage 54 , and a pressure sensor 68 connected to the mixing chamber 60 monitors a pressure of the heated main gas.
[0026] A powder injector tube 70 is in fluid communication with the supplemental inlet line 50 and directs the mixture of the gas and the powder particles 22 to the mixing chamber 60 to supply the mixing chamber 60 with the powder particles 22 . The powder injection tube extends through the premix chamber 56 and the flow straightener 58 into the mixing chamber 60 . Preferably, the injector tube has an inner diameter between the ranges of 0.3 millimeters to 3.0 millimeters, and is aligned collinear with a central axis C of the nozzle assembly 48 .
[0027] The conditioning chamber 62 is positioned between the powder-gas mixing chamber 60 and a convergent portion 72 (described below) of the nozzle assembly 48 . The conditioning chamber 62 increases the temperature of the powder particles 22 prior to mixing the powder particles 22 with the heated main gas flowing through the nozzle assembly 48 . Preferably, as shown in FIG. 2 , the conditioning chamber 62 is disposed upstream of the convergent portion 72 . The conditioning chamber 62 includes a length along a longitudinal axis B, preferably collinear with the central axis C of the nozzle assembly 48 . The interior of the conditioning chamber 62 has a cylindrical shape having an interior diameter equal to the inlet 77 of the convergent portion 72 of the nozzle assembly 48 . The conditioning chamber 62 releasably engages the convergent portion 72 of the nozzle assembly 48 and the powder-gas mixing chamber 60 . Preferably, the releasable engagement is by correspondingly engaging threads (not shown) between the exchange chamber, the convergent portion 72 , and the conditioning chamber 62 respectively. It should be understood, however, that the releasable engagement may be through other devices such as a snap fit connection, a bayonet-type connection, or some other suitable type of connection. The length along the longitudinal axis B is preferably at least 20 millimeters or longer. The optimal length of the conditioning chamber 62 depends on the particles that are being sprayed and the substrate material 24 . The optimal length can be determined experimentally, but is preferably between the ranges of 20 millimeters to 1000 millimeters.
[0028] As best shown in FIG. 3 , the nozzle assembly 48 includes the convergent portion 72 , which defines an inlet 77 and an outlet 74 . The outlet 74 is in spaced relationship relative to the inlet 77 . A divergent portion 76 defines an entrance 78 and an exit 80 , with the exit 80 being in spaced relationship relative to the entrance 78 . A throat portion 82 interconnects the outlet 74 of the convergent portion 72 and the entrance 78 of the divergent portion 76 . The convergent portion 72 , the throat portion 82 , and the divergent portion 76 form a de Laval type converging diverging nozzle as is known in the art, and cooperate together to define a passage 66 therethrough. The passage 66 includes a perimeter 84 , which narrows between the inlet 77 and the outlet 74 of the convergent portion 72 and expands between the entrance 78 and the exit 80 of the divergent portion 76 . An extension portion 86 further defines the passage 66 and extends from the exit 80 of the divergent portion 76 to a distal end 88 spaced a pre-determined length L from the exit 80 . The pre-determined length L of the extension portion 86 is between the ranges of 20 millimeters and 1,000 millimeters. Accordingly, the nozzle assembly 48 includes an overall length spanning the convergent portion 72 , the throat portion 82 , the divergent portion 76 , and the extension portion 86 between the ranges of 100 millimeters and 1,500 millimeters.
[0029] Based on aerodynamics, a drag force is applied to the powder particles 22 by the flow of heated main gas. The drag force may be expressed by the equation:
[0000] D= ½ ·C p ·ρ g ·( V g −V p ) 2 ·A p
[0030] Wherein C p is a drag coefficient, ρ g is a density of the heated main gas, V g is a velocity of the heated main gas, V p is a velocity of the powder particles 22 , and A p is an average cross sectional area of the powder particles 22 . The drag force accelerates the powder particles 22 to a critical velocity. It has been discovered that there is a wasted potential in the drag force because the powder particles 22 are not exposed to the drag force for a long enough period of time, i.e., the powder particles 22 may achieve a higher velocity if the powder particles 22 are exposed to the drag force for a longer period of time. Accordingly, by adding the extension portion 86 onto the divergent portion 76 of the nozzle assembly 48 , the powder particles 22 are exposed to the drag force for a longer period of time, thereby minimizing the wasted potential, and thereby maximizing the drag force applied to the powder particles 22 .
[0031] The heated main gas flows through the convergent portion 72 , throat portion 82 , and then into the divergent portion 76 , where the heated main gas accelerates to high velocities. As the velocity of the heated main gas increases, the density of the heated main gas decreases. This is evident with reference to the conservation of mass within the nozzle assembly 48 expressed by the equation:
[0000] f=A·V g ·ρ g .
[0032] Wherein f is a mass flow rate of the heated main gas, A is a cross sectional area of the perimeter 84 of the nozzle assembly 48 at any given location within the passage 66 , V g is the velocity of the heated main gas, and ρ g is the density of the heated main gas. The decrease in the density of the heated main gas negatively affects the drag force. Additionally, an expansion ratio defined as a rate of change of the perimeter 84 of the passage 66 over a distance along the central axis C extending through the passage 66 limits the increase in the velocity achievable in the divergent portion 76 . As the heated main gas flows through the divergent portion 76 , a boundary layer near an outer wall of the nozzle assembly 48 develops, and tends to separate, creating a shock wave in the flow of heated main gas. The shock wave significantly decreases the velocity of the heated main gas. Accordingly, it is not effective to merely extend the divergent portion 76 of the nozzle assembly 48 outward. Therefore, the perimeter 84 of the passage 66 defined by the extension portion 86 is at least equal to or greater than the perimeter 84 of the passage 66 defined by the exit 80 of the divergent portion 76 . It should be understood that the perimeter 84 of the passage 66 defines a cross sectional shape. Referring to FIGS. 3 and 4 , the cross sectional shape defined by the perimeter 84 may be uniform throughout the pre-determined length L of the extension portion 86 . It should be understood that the uniform cross sectional shape of the extension portion 86 includes an expansion ratio equal to zero or negligibly small. Alternatively, referring to FIGS. 5 and 6 , the cross sectional shape of the perimeter 84 defined by the extension portion 86 may slightly increase in area relative to the exit 80 of the divergent portion 76 as the extension portion 86 extends from the exit 80 of the divergent portion 76 to the distal end 88 of the extension portion 86 . Nevertheless, the slightly increasing cross sectional shape defined by the extension portion 86 includes a significantly smaller expansion ratio relative to the expansion ratio of the divergent portion 76 . The uniform cross sectional shape and the alternative slightly increasing cross sectional shape defined by the perimeter 84 of the extension portion 86 permit the drag force to act on the powder particles 22 for a longer period of time without significantly decreasing the density of the heated gas, and also without creating the shock wave within the flow of heated gas.
[0033] As described above, the expansion ratio of the passage 66 defined by the divergent portion 76 is greater than the expansion ratio of the passage 66 defined by the extension portion 86 . This permits the heated main gas to flow through the extension portion 86 without continuing to decrease the density of the heated main gas and to avoid shock waves in the heated main gas. While it is contemplated that the divergent portion 76 may include a constant expansion ratio as shown in FIGS. 3 and 5 , the expansion ratio of the divergent portion 76 preferably continuously decreases from the entrance 78 to the exit 80 of the divergent portion 76 as shown in FIG. 7 . This may further be described as having a parabolic or curved shape that continuously diverges from the central axis C at a continuously decreasing rate as the distance from the entrance 78 of the divergent portion 76 increases in a direction toward the exit 80 of the divergent portion 76 . The parabolic or curved shaped divergent portion 76 provides the greatest possible expansion ratio immediately downstream of the throat portion 82 , thereby rapidly increasing the velocity of the heated main gas near the throat portion 82 than near the extension portion 86 to maximize the velocity difference between the heated main gas and the powder particles 22 and to increase the drag force applied on the powder particles 22 . Accordingly, the divergent portion 76 has the largest expansion ratio nearest the throat portion 82 , and the smallest expansion ratio at the exit 80 of the divergent portion 76 . As a result, the gas pressure at the divergent portion 76 drops rapidly due to a high expansion ratio. This allows the powder particles 22 to be injected by a low pressure powder feeder 42 through the powder injector tube 70 as shown in FIG. 7 .
[0034] The cross section of the perimeter 84 defined by the divergent portion 76 and the extension portion 86 may include a variety of shapes, but preferably includes a rectangular shape. The rectangular shaped cross section of the perimeter 84 defined by the extension portion 86 at the distal end 88 includes a long dimension between the range of 6.0 millimeters and 24.0 millimeters and a short dimension between the range of 1.0 millimeters and 6.0 millimeters. Alternatively, as shown in FIG. 9 , the perimeter 84 of the passage 66 defined by the divergent portion 76 and the extension portion 86 may define a cross section having a circular shape.
[0035] Preferably, as indicated in FIG. 5 , the extension portion 86 is releasably attached to the divergent portion 76 . The releasable attachment may be by correspondingly engaging threads between the divergent portion 76 and the extension portion 86 , a snap fit connection, a bayonet type connection, or some other suitable connection. However, as shown in FIG. 3 , it is contemplated that the extension portion 86 may be integrally formed with the divergent portion 76 as a single unit.
[0036] The perimeter 84 of the passage 66 defined by the throat portion 82 defines a cross section. As shown in FIG. 9 , the cross section may include a circular shape. The circular shaped cross section of the throat may include a diameter between the ranges of 1.0 millimeters and 5.0 millimeters. However, it should be understood that the cross section of the throat portion 82 may include other shapes. Preferably, referring to FIGS. 4 and 6 , the cross section of the throat portion 82 includes an elliptical shape. Excessive wear in the rectangular shaped cross section of the divergent portion 76 adjacent the throat portion 82 has been noticed. The excessive wear negatively affects the performance of the nozzle assembly 48 . The excessive wear has been attributed to rapid radial expansion of the heated main gas and powder particles 22 exiting the circular shaped cross section of the throat portion 82 . This excessive wear is reduced by elongating the cross section of the throat portion 82 . Accordingly, the elliptically shaped cross section of the throat portion 82 helps minimize the excessive wear noticed in the rectangular shaped cross section of the divergent portion 76 .
[0037] Referring to FIGS. 7 and 8 , an alternative embodiment of the nozzle assembly 48 is shown. In the alternative embodiment, the particle injector tube interconnects the conditioning chamber 62 and the divergent portion 76 of the nozzle assembly 48 to supply the powder particles 22 to the divergent portion 76 of the nozzle assembly 48 . The mixing chamber 60 is disposed within the divergent portion 76 , adjacent the throat portion 82 , for mixing the powder particles 22 with the flow of heated main gas in the divergent portion 76 of the nozzle assembly 48 as the heated main gas enters the divergent portion 76 from the throat portion 82 . In the alternative embodiment, the longitudinal axis B of the conditioning chamber 62 is not collinear with the central axis C, and in fact, the conditioning chamber 62 is separated from the nozzle assembly 48 . The particle injector tube interconnects in fluid communication the conditioning chamber 62 and the mixing chamber 60 within the divergent portion 76 . Powder buildup and clogging of the throat portion 82 is thereby minimized by providing the powder particles 22 directly into the divergent portion 76 of the nozzle assembly 48 instead of directing the powder particles 22 through the throat portion 82 . In the alternative embodiment, the gas pressure in the divergent portion 76 drops rapidly due to the high expansion ratio. This enables the powder particles 22 to be injected at a lower pressure (less than 100 psi), compared to the preferred embodiment shown in FIG. 2 , which injects the powder particles 22 at a higher pressure (typically greater than 300 psi). Furthermore, a detached conditioning chamber 62 may be included that uses external heating to heat the powder particles 22 to an elevated temperature (up to 80% of the melting temperature of the powder particles 22 ). The detached conditioning chamber 62 is in fluid communication with the divergent portion 76 through the powder injector tube 70 , as shown in FIG. 7 . Alternatively, the detached conditioning chamber 62 may also be in fluid communication with the premix chamber 56 through the powder injector tube 70 , as shown in FIG. 2 .
[0038] The foregoing invention has been described in accordance with the relevant legal standards; thus, the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiments may become apparent to those skilled in the art and do come within the scope of the invention. Accordingly, the scope of legal protection afforded this invention can only be determined by studying the following claims.
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A nozzle assembly for a kinetic spray system includes a convergent portion, a throat portion, and a divergent portion, each cooperating together to define a passage therethrough for passing a mixture of powder particles suspended in a flow of a high pressure heated gas. The nozzle assembly further includes an extension portion attached to the divergent portion and extending to a distal end a pre-determined length from the divergent portion of the nozzle assembly. The extension portion permits a dragging force exerted on the powder particles by the flow of high pressure heated gas to act upon the powder particles for a longer duration of time, thereby permitting the powder particles to accelerate to a greater velocity than has been previously achievable.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to cargo tie down devices, particularly in aircraft for securing cargo pallets that require quick release adjustment tensioning devices retaining the cargo pallets within the aircraft before release and airborne delivery.
2. Description of Prior Art
Prior art devices of this type are directed to cargo securing and tensioning devices that are used to secure cargo in vehicles including aircraft. Such devices have been specifically developed for these environments with a variety of adjustable features that are required; see for example U.S. Pat. Nos. 7,334,955, 7,249,907, 5,702,196 and 5,159,729.
In U.S. Pat. No. 5,159,729, a tie down device is disclosed for cargo that includes a first and second end with an adjustable turnbuckle assembly so that an engagement strap and hook can be adjusted by rotation longitudinally.
U.S. Pat. No. 5,702,196 claims a turnbuckle type adjustable link wherein the turnbuckle has a threaded engagement first rod and a threaded second rod with an intermediate adjustment sleeve and intermediate resilient springs.
U.S. Pat. No. 7,249,907 illustrates a spring-loaded turnbuckle with a quick disconnect having a spring-loaded rod with an attachment hook. A pivot housing is provided on an opposing upper end with an aperture for locking via a pin or padlock.
U.S. Pat. No. 7,334,955 discloses a turnbuckle assembly for a tension member wherein a pivot handle has a bottom pivot housing allowing for adjustable end and angular pivot orientation thereto.
Other prior art cargo tensioning tie downs have been disclosed including an air cargo device that has an adjustable hook for an aircraft engagement with a spring release load chain retainment release in a fixed orientation to one another.
SUMMARY OF THE INVENTION
An improvement to an air cargo adjustable tensioning tie down device which is used to selectively secure loaded cargo pallets within an aircraft. Specifically, cargo tie down requirements entail the use of quick release tensioning devices wherein secured cargo must be released in flight for air cargo drop by transport aircraft. Such cargo tie downs must be visual inspected to assure proper and safe engagement and therefore the orientation of the cargo tie down for inspection is critical. The adjustable cargo tie down device of the invention allows for the engaged tie down to be axially rotated while engaged under tension to enable ease of visual inspection. A spring urged sliding rod engagement bracket can be disengaged allowing the entire tie down assembly to be rotated 180 degrees for inspection without effecting the cargo tie engagement.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the tie down with a portion cut-away.
FIG. 2 is an enlarged partial top plan view illustrating the spring-urged tension rotational adjustment in engaged position and alternately in displaced position for imparted axle rotation as shown in broken lines.
FIG. 3 is an enlarged partial bottom plan view thereof.
FIG. 4 is an enlarged cross-sectional view on lines 4 - 4 of FIG. 2 .
FIG. 5 is an enlarged top plan view of the rotational adjustment broken away in lock engaged non-rotational position.
FIG. 6 is an enlarged top plan view thereof in unlocked rotational position.
DETAILED DESCRIPTION OF THE INVENTION
An adjustable cargo tensioning device 10 of the invention can be seen in FIG. 1 of the drawings having a hook portion 11 and a release portion 12 . The hook portion 11 has a hook member 13 with an integrated spring-urged pivot access arm 14 that selectively pivots open for hook engagement as will be well known by those skilled in the art.
The hook 13 has and is integral with a threaded adjustment rod 15 which extends therefrom to the release portion 12 . An annularly adjustment fitting 16 is threadably disposed on the rod 15 between the hook 13 and the release portion 12 which allows for incremental longitudinal rod adjustment effective length and therefore that of the hook 13 as will be described in greater detail hereinafter.
The release portion 12 has an elongated U-shaped support frame 17 enclosing same with spaced parallel sidewalls 18 A and 18 B with an interconnecting integral end wall 19 , best seen in FIG. 2 of the drawings. The sidewalls 18 A and 18 B are additionally interconnected by three primary cross support rod fittings 19 , 20 and 21 . The support fitting 19 functions as a bearing pivot rod for a common load chain engagement and release fitting 22 having a cast contoured body member 23 with a pair of engagement paws 24 extending therefrom in spaced parallel relation to one another.
A chain release assembly 25 , as seen in FIGS. 2 and 3 of the drawings, selectively engages with the chain engagement fitting 22 for retainment and release thereof when so engaged by a chain under load. The chain release assembly 25 has a activation release handle 26 with integrated spaced parallel apertured end tabs 27 extending therefrom and is pivotally secured to apertured aligned detents 28 in the respective sidewalls 18 A and 18 B by a support rod 29 extending therethrough as best seen in FIG. 2 of the drawings.
An index engagement release arm 30 extends from the central portion of the support rod 29 with a split spring assembly 31 positioned on the rod 29 on either side thereof providing resilient retainment thereto when the release handle 26 is so engaged with the chain engagement retainment and release fitting 22 .
The cross support rod 21 extends in spaced parallel relation thereto and acts as a spring stop at 32 for the terminal end of the split coil spring 33 .
It will therefore be seen that the spring urged release chain engagement fitting release assembly 25 maintains the chain engagement fitting 22 in locked position holding the chain, not shown, securely therewithin during use as will be understood by those skilled in the art. Upon lifting the release handle 26 as indicated in broken lines in FIG. 1 of the drawings, the interengagement with the chain engagement fitting 22 is achieved, releasing it from its locked safety position.
Referring now to FIGS. 1 , 2 and 3 of the drawings, the hook release and tensioning device rotation assembly 10 of the invention can be seen. The hooks 13 integral threaded rod 15 extends, as noted, through an adjustment engagement fixture 35 , best seen in FIGS. 3 and 4 of the drawings having the “fine” annular adjustment fitting 16 threadably disposed thereon with a selective thread rod engagement assembly 36 within the support frame 17 which allows selective rod rotational release for incremental “fine” longitudinal positioning adjustment by rotation of the annular adjustment fitting 16 to assure proper tensioning of the cargo load, not shown. A release and lock activation lever tab 37 can be seen in FIGS. 3 and 4 of the drawings to afford selective release allowing for rotatable adjustment as hereinbefore described.
The key improvement introduced by the nature of the invention is a rotational rod release assembly 38 which can be seen as having a rod rotation retainment bar 39 extending transversely between the respective sidewalls 18 A and 18 B, each of which has a correspondingly longitudinally extending guide bar receiving slots 40 A and 40 B therein, in spaced parallel aligned relation to one another.
The rod rotation retainment bar 39 has oppositely disposed slot support engagement rods 41 A and 41 B extending therefrom for registration through the respective slots 40 A and 40 B with corresponding enlarged finger engagement fittings 42 A and 42 B on their respective free ends beyond the outer surface of the sidewalls 18 A and 18 B for tactile engagement by the user, not shown, as will be described hereinafter indicated by direction engagement arrows A.
The rod rotational retainment bar 39 has a central bore at 43 extending transversely therethrough with an intersecting bar retainment channel 44 in a bar's surface 45 best seen in FIGS. 5 and 6 of the drawings. Correspondingly, the hereinbefore described threaded rod 15 has a non-threaded end portion 46 extending inwardly from its free end 47 . A rotation fixation pin 48 extends through a pin receiving bore 49 transversely through the non-threaded end portion 46 of the rod 15 as shown in FIG. 6 of the drawings and in broken lines in FIG. 5 of the drawings. A spring 50 is positioned on the non-threaded rod end portion 46 so as to engage between the rod rotation retainment bar 39 and a threaded transition shoulder 51 formed on the rod 15 as will be understood within the art.
As assembled, the rotational rod release assembly 38 maintains a fixed orientation between the frame 16 and the hook 13 . However, by engagement of the respective finger engagement fittings 42 A and 42 B the rod rotation retainment bar 39 can be moved against the resistance of the spring 50 so as freeing the rotation fixation pin 48 from the bar retainment channel 44 allowing the frame 16 to be rotated relative to the engaged position of the hook 13 orientation to assure that visual inspection of the cargo tensioning device 10 and its associated chain engagement fitting 22 has been achieved.
It will be evident from the above description that the effective “fine” longitudinal adjustment of retainment tension can still be achieved, as noted, by rotation of the annular adjustment fitting 16 without effecting the functional retainment of the rotational rod release assembly 38 .
Therefore given the effective longitudinal placement under length associated requirements dependent on load configuration, the rod rotation retainment bar 39 within its respective guide slots 39 and 40 will accommodate operation within the full linear range adjustment possible to the threaded rod 15 and integral hook 13 .
It will thus be seen that a new and novel adjustable cargo tensioning device for securing a load in an aircraft has been illustrated and described and that by utilization of the rotational rod release assembly 38 , the effective orientation of the frame 16 and thus visual inspection of proper engagement and securing of the load retaining elements therewithin can be achieved.
It will be evident to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention, therefore I claim:
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An adjustable cargo tie down tensioning device for securing cargo in an aircraft and the like comprises, a spring loaded tie down chain restraint release and an adjustable connector having a surface engagement hook. The hook has an integrated threaded shaft with a spring urged retainment release for axle rotation once engaged assuring tie down device tensioning surface orientation for visual inspection of spring engaged chain restraint release required for load surface safety requirements.
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TECHNICAL FIELD
The present invention relates to a method of separating a major portion of the covered surfaces of articles which are in a stack and, more particularly, to the drying or curing of coating compositions, including sealants, on container closures and the like wherein said closures are arranged in a stacked relationship.
BACKGROUND OF THE PRIOR ART
Closures for metal beverage containers are generally of a circular shape with a flanged perimeter. The flanged perimeter is used in attaching the closure to a can body through a seaming operation. To aid the integrity of the seal thus formed between the can body and the closure, it is a common practice to apply a bead of sealant within the flanged perimeter during manufacture of the closure.
One problem which arises in this manufacturing operation is the curing or drying of such sealants. To facilitate handling of the closures after the application of a sealant, the closures are often accumulated into a columnar stack and transported to the next operation through appropriate trackwork. When the closures are in such a stacked condition, it is difficult or impossible to direct energy waves such as heat or moving air across the sealant to accelerate the drying process. The flange, in combination with the adjacent stacked closure, effectively shields the sealant from outside influences.
When the sealant is of the solvent-based type, this is not a severe problem. Even in the stacked condition, the volatile solvent quickly evaporates and within 24 to 48 hours the sealant is acceptably dry for application of the closure to a can body.
Recently there has been an increased interest in the use of water-based sealants in the container industry. These sealants present much greater difficulty in quick and effective drying. Very slow drying takes place and it may take up to 10 days for the sealant to dry to an acceptable state for application of the closure to a can body.
Prior to the present invention, the achievement of practical drying times for water-based sealants required complicated apparatus to unstack the closures and transport them, one at a time, through a hot air blowing station thereby allowing streams of air to directly impinge the sealant and effectively dry it. Apparatus used in such an operation has many drawbacks, mainly due to its complexity, high cost, and expansive floor space requirements.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a simple way to expose the covered surfaces of stacked articles and as applied to closures, to provide direct access of the sealant thereon to a moving stream of air. Although the present invention is particularly suitable to the drying of closures, it is to be appreciated that it has much broader application in various situations where the separation of stacked articles is desired for drying, treating or other purposes.
In accordance with the present invention, a portion of the covered surfaces of a stack of articles is exposed by pushing the stack through a first curvilinear path and allowing said articles to pivot on the portions of said covered surfaces proximate to the focus of said curvilinear path whereby the portion of said covered surfaces distal to said focus will separate in a fan-like manner. Where the complete surface of said article is to be exposed, the above operation is repeated using a second curvilinear path of a different direction that the first curvilinear path or the articles may be rotated while traversing the curved path. In effect, the orientation of the article is maintained relative to the curvilinear direction of travel at a constant. This results in the portion of the articles traversing the longer outer curve separating from adjacent articles while the portion of the articles traversing the shorter inner curve remain in contact thereby forming a fan-like pattern around the path. This may generally be accomplished by suitable track means and an indexing or other type of pushing means located at the beginning of said track means.
Essentially any series of uniform semi-rigid or rigid articles in a stacked relationship which can be pushed and guided through a curved path while maintaining a fixed orientation relative to the direction of travel therethrough can be operated on in accordance with the present invention. Stacked planar articles, those having at least two substantially parallel opposing surfaces in abutting face-to-face contact and a relatively small width dimension, are especially suited for treatment hereunder due to the large portion of the abutting surfaces which are inaccessible.
In the application of the present invention to the drying of closures, suitable track means are constructed to confine the closures to a predetermined path through a drying station. In one arrangement, said predetermined path has a number of reversing curves. An air stream, which is preferably heated, is directed across these curves. The closures are then pushed through the curves by a pushing means situated at the beginning of said track means. As the closures traverse a curve, the portion of the closures traversing the longer outer curve separate in a fan-like manner allowing direct access to the sealant by the air stream. In the traverse of two curves at opposite directions, the complete perimeter of the closure is made accessible to streams of heated air. Greater uniformity in drying may be accomplished by rotating the closures through at least one complete revolution as a curve is traversed.
Accordingly, it is an object of this invention to provide a way of separating a portion of an article from adjacent portions of similar articles where said articles are in a stack.
It is another object of this invention to provide a method and apparatus for exposing and treating the unexposed surfaces of articles which are in a stack.
It is a further object of this invention to provide a method and apparatus for drying or curing coatings on the unexposed surface of articles which are stacked.
It is a further object of the present invention to provide a simple and reliable way to quickly dry water-based sealant on beverage closures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an asymmetric drawing of a closure dryer constructed in accordance with the present invention.
FIG. 2 is an end view of the entrance to the closure dryer.
FIG. 3 is a cross-sectional view of a closure traversing the outermost portion of a curve in a first direction in the dryer.
FIG. 4 is a detailed cross-sectional view of the trackwork of the dryer.
FIG. 5 is a top view corresponding to the cross-sectional view of FIG. 4.
FIG. 6 is a typical closure operated on by the dryer.
FIG. 7 is a cross-sectional view of a closure traversing a curve in an opposite direction to that of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
While this invention is susceptible to embodiment in many different forms, there is shown in the drawings and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.
Referring to FIG. 1, a beverage closure dryer constructed in accordance with the present invention is generally referenced by the numeral 10. The dryer has an enclosure 15 with insulated walls 11; two entrances 12 and two exits 13; two trackworks 14 and 24 between said entrances and exits, each of said trackworks having four rails 29, the ends of which are retained in rectangular openings 28 in enclosure 15; four linear nozzles 16, one on each side of each trackwork; a planar baffle 17, extending outwardly from the top rails of said trackworks; a high frequency vibrator 33 attached to trackworks 14 and 24 through extensions 41; and a fan 18 which removes air from exhaust compartment 19 above baffle 17 and forces said air through heater 20 into hot air receiving compartment 21 and through linear nozzles 16 which direct said air to trackworks 14 and 24.
Entrances 12 to closure dryer 10 are better shown in FIG. 2, which is an end view of the dryer. The ends of rails 29 rest securely in rectangular openings 28. A pushing means for each trackwork must be located upstream of the dryer such as resilient wheel drive 22, which is mounted at each dryer entrance 12. Each of the drives comprises two resilient wheels 25 mounted on drive shafts 26 from synchronized motor means 27. The wheels on each of said resilient wheel drives are spaced apart to grasp closures and push said closures through entrance 12. The resilient wheel drives are secured to enclosure 15 by bolts 30. A second pushing means or resilient wheel drive may be placed at each exit 13 of dryer 10 to minimize the back pressure placed on closures traveling through the dryer. A second wheel drive should only be necessary where closures must travel a significant length of trackwork to the operation subsequent to the dryer.
A typical closure 23 to be operated on by the present invention is shown in FIG. 6. Said closure has a flange 36 around the outer periphery thereof, and a bead of sealant 42 adjacent to said flange. A series of closures 23 may be introduced to resilient wheel drive 22, each closure being indexed forward by said wheel drive and pushed through the trackwork by subsequently introduced and indexed forward closures. Any conventional means may be used to introduce closures to resilient wheel drive 22, such as downward sloping trackwork, or a conveyor with vacuum assist directly from a sealant applicator.
The trackwork construction is shown in FIG. 4 which is a cross-sectional end view of trackwork 14 at line 4--4 of FIG. 1. Corresponding to end view FIG. 4 is top view FIG. 5 illustrating closures 23 traversing the curve of line 4--4 in FIG. 1.
The trackwork of the preferred embodiment is constructed of two upper rails 31, two lower rails 32 and a series of retainers 37 which secure the rails in appropriate spaced relationship and provide the added function of preventing closures from dropping through the trackwork. Only a portion of trackwork 14 is illustrated as trackwork 24 is of similar construction and the configuration of the remaining portions of both trackworks will be readily apparent from the drawings and description.
A number of other trackwork designs may be operable with the present invention including configurations having various numbers of rails and retainers as long as the trackwork maintains the orientation of the articles at a constant relative to the direction of travel, allows free movement of treating medium to reach the articles, and has a nominal coefficient of friction with the articles.
It has been found that a four-rail system, with the to be described configuration, is ideal in minimizing friction and jamming, allowing free movement of air and separating the articles. In the preferred embodiment, upper rails 31 are spaced such that upper contact surfaces 34 are X distance apart and positioned in a first horizontal plane, lower rails 32 are spaced such that lower contact surfaces 35 are Z distance apart and positioned in a second horizontal plane, said first and second horizontal plane being substantially parallel and having a perpendicular distance of Y between them. Where closure 23 (FIG. 6), which is to be operated on by the present invention, has a diameter of D, distance X is preferably between about 0.89D and 0.99D, distance Z is between about 0.45D and 0.55D, and distance Y is between about 0.77D and 0.87D. Empirical testing has yielded excellent results where X is 0.95D, Y is 0.82D and Z is 0.50D inches.
The configuration of the preferred embodiment is advantageous in minimizing friction and jamming of closures. This is achieved by supporting closures traversing the trackwork with a maximum of two contact surfaces, both of said surfaces being on the same side of the closure. Dotted line 43 of FIG. 4 illustrates the position of a closure traveling along a straight section of the trackwork while FIGS. 3 and 7, which are, respectively, cross-sectional views of the left curve at line 3--3 and the right curve of line 7--7 of FIG. 1, illustrate a closure traversing curves in both directions. Empirical testing of this design has shown that, when constructed in accordance with the above-disclosed parameters, frictional forces are nominal and jamming is virtually nonexistent.
The radius R and sector S of curves in trackwork 14 are interrelated in that a decrease in radius will allow greater airflow through the closures while an increase in sector will hold the closures open over a greater length of time, thereby providing greater drying. A conflicting consideration is the increased friction which results as the radius is decreased or the sector is increased. To achieve sufficient drying while minimizing friction it has been found best to use a series of reversing curves having relatively small sectors of between 35 and 55 degrees. Satisfactory results have been obtained in production line tests using seven curves of a center radius of about three times the diameter of the closures operated on and having a sector of about 45°. This results in a separation of between 1/16 and 3/16 of an inch between adjacent closures when traversing a curve. Friction may also be lowered and greater fanning of closures achieved by attaching a high-frequency, low-amplitude vibrator 33 to the trackwork. Due to the increased risks of fatigue and other problems which may result from exposure to vibration, it is thought undesirable to use such a vibrator unless necessary to obtain sufficient drying.
A variety of other curve designs are contemplated by the present invention including reversing curves in a vertical plane and a descending spiral curve. The preferred embodiment is designed to fit directly into existing closure lines without upstream or downstream modifications.
A significant feature of the present invention which makes production line operation substantially trouble-free are the retainers best shown in FIGS. 4 and 5. These retainers are spaced a maximum distance of P apart such that distance A is less than 2/3D where D is the diameter of the closures. To achieve maximum drying it is desirable to minimize interference of airflow from nozzle 16. However, where a rail system is used alone without retainers 37, the startup or stoppage of a production line operation may result in some of the closures becoming unstacked and falling through the trackwork. This can result in jams and spills thereby requiring costly delays and corrective action. It has been found that retainers with the spacing disclosed herein allow startup of a line even when closures are scattered throughout the trackwork and lying down therein. Any closer spacing detracts from the drying by obstructing air from nozzle 16, while greater spacing than that disclosed may result in jamming or spillage when starting up the dryer after closures become unstacked.
As shown in FIGS. 3 and 7, a planar baffle 17 rests on and extends outwardly from the upper rails 31 of each trackwork, said baffle extending between both trackworks and being connected to enclosure 15. This baffle increases the energy-efficient operation of the dryer by helping direct the airflow between the open portions of the closures.
Two linear nozzles 16 are positioned below and to the sides of each trackwork, said nozzles having a taper angle of d, a length of B, and an opening width of C. Preferably said nozzles are directed at a 45° angle from vertical toward the longitudinal axis of the trackwork at the points said linear nozzle forms a tangent to and is in its closest position to said trackwork, one of said points being referenced as 36 in FIG. 5. In a trackwork constructed in accordance with the herein specified parameters, the linear nozzle provides the additional function of rotating closures which are traversing the curves. As shown in FIG. 4, which is a cross-sectional view of trackwork 14 at the outermost point of a curve, the nozzle positioned on the inside of the curve directs a stream of air to impinge the closure tangentially at area 47. This generates tangential forces which cause clockwise rotation of the closure. Closures traversing curves in the opposite direction to that shown in FIG. 4 are rotated counterclockwise by the opposite linear nozzle. Greater uniformity in drying is achieved if the closure is rotated at least once in traversing a curve.
A variety of different fans and heaters may be utilized with the dryer depending on the line speed, amount of sealant on the closures, and the drying desired. Generally, best results will be achieved if a sufficient airflow is created to result in an air speed of about 4,000 feet per minute at the nozzle. This provides good penetration of air into the stack of closures and assures rotation of the closures by the inside nozzle.
It has been found that a dryer having four-foot track sections and one-inch insulated walls, that is constructed in accordance with the above parameters for 2.73 inch diameter closures, can be heated to above 200° F. with a 12 kw heater while two lanes of closures are being dryed at up to 380 closures per minute per lane. Generally, closures having between 40 and 80 miligrams of water soluble sealant on them, which is about 65 percent total solids, will be dryed to in excess of 97 percent total solids by the dryer if the air in the hot air receiving compartment is above 190° F. and vibrator 33 is not used. With most commercially available waterborne sealant compounds, drying to 95 percent total solids, and preferably 97 percent, is sufficient for application of the closure to a canbody.
INDUSTRIAL APPLICATION
The present invention has industrial application in the metal beverage container industry.
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The present invention discloses a way of separating and treating the covered surfaces of stacked articles in abutting face-to-face contact. It is particularly applicable to stacked planar articles, those having a relatively small width dimension and at least two substantially parallel surfaces in abutting contact, such as metal beverage container closures. The articles are pushed through a curvilinear path defined by a constant width trackwork of a herein specified design, allowed to pivot on the portions of the articles in proximity to the shorter radius whereby fan-like separation of the portions in proximity to the longer radius occurs, and treating medium, such as heated air, is directed toward the separated portions. Greater uniformity in treatment may be obtained by rotating the articles, at least once, as they traverse the curvilinear path. A preferred embodiment designed to dry the sealant on metal beverage container closures is disclosed herein.
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INCORPORATION BY REFERENCE
The present application claims priority from Japanese application JP2008-131454 filed on May 20, 2008, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a method for recording information on and/or reproducing information from optical information recording media by using holography.
Optical disc products with a recording density of about 50 GB are being commercialized that are based on Blu-ray Disc (BD) standard and High Definition Digital Versatile Disc (HD DVD) standard using a blue semiconductor laser.
Optical discs are expected to have an increased capacity of as large as 100 GB to 1 TB, comparable to that of HDD (Hard Disc Drive), in the future.
However, to realize such an ultrahigh density with the current optical discs, a novel storage technology is required, different from the conventional trend of high density technologies that attempts to increase the storage capacity by shortening a wavelength and increasing NA of an object lens.
With a wide-ranging studies on next generation storage technologies under way, a hologram recording technology is available that records digital information using holography.
Among the hologram recording technologies is one disclosed in JP-A-2004-272268. This patent document describes a so-called angle-multiplexing recording method which focuses a signal beam flux on an optical information recording medium through a lens and at the same time throws a reference beam of collimated rays to the medium to cause interferences to record a hologram and displays different pages of data on a spatial light modulator by changing an incidence angle of the reference beam to the optical recording medium to realize multiplex recording. The patent document also discloses a technology that puts an aperture (spatial filter) at a beam waist of a lens-focused signal beam to shorten the intervals of adjoining holograms, thereby increasing the recording density and capacity, compared with those of the conventional angle-multiplexing recording method.
Another hologram recording technology is disclosed in, for example, WO2004-102542. This document describes an example of shift multiplexing hologram recording method which, in one spatial light modulator, focuses a light from inner pixels as a signal beam and a light from outer ring-like pixels as a reference beam onto an optical recording medium through one and the same lens to cause interferences between the signal beam and the reference beam at near the focus plane of the lens to record a hologram.
There is an encoding method used for the above hologram recording, such as one disclosed in JP-A-9-197947. This patent document describes a 2-dimensional encoding method for hologram recording which throws at least one light wave through a 2-dimensional spatial light modulator to determine information to be recorded, characterized in that four adjoining pixels or 4-multiples of pixels in the 2-dimensional spatial light modulator are taken as one set and that one fourth of the number of pixels making up each set is made to pass the light and the remaining three fourths are made to interrupt it.
Another example of the conventional technology is JP-A-2005-190636, which provides “a holographic recording method, a holographic memory reproducing method, a holographic recording apparatus and a holographic memory reproducing apparatus, designed to improve an encoding rate by preventing variations in reproduced imaged intensity even if pixel blocks of different numbers of ON pixels are mixedly used.”
SUMMARY OF THE INVENTION
In the method described in JP-A-2004272268 which applies the encoding technique of JP-A-9-197947 or in the method described in WO-2004-102542 which applies the encoding technique of JP-A-9-197947, 2-dimensional data of FIG. 12C is obtained by performing the encoding of FIG. 12B on data strings of FIG. 12A . These methods however, have a drawback of consuming a four-bit area to produce 2 bits of information and therefore being unable to improve the recording density. The method that simply transmits light with “1” and blocks light with “0” results in light transmissivity varying from one page to another. This difference in transmissivity causes different pages, when reproduced, to have different levels of reproduced image brightness, giving rise to a possibility that an erroneous decision may be made when the reference values for binarization decision are equal. There is another problem that consumption of dynamic range in a hologram recording medium is not constant.
Further, JP-A-2005-190636 does not take into account a possibility of the light transmissivity varying among different pages when pixel blocks with different ON-pixel numbers are mixedly used.
An object of this invention is to provide an encoding method capable of improving the recording density while keeping the transmissivity constant among different pages.
The object of this invention can be realized by, for example, controlling a 2-dimensional data arrangement.
In the recording of digital information using holography, this invention allows for improvement of the digital density while keeping the transmissivity constant among different pages.
Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall configuration of an optical information recording/reproducing apparatus according to an embodiment.
FIG. 2 is a schematic view showing an example of a pickup in the optical information recording/reproducing apparatus.
FIGS. 3A-3C are flow charts showing an example of operation flow performed by the optical information recording/reproducing apparatus.
FIG. 4 is a flow chart showing an example of operation performed by the optical information recording/reproducing apparatus during data recording.
FIG. 5 is a flow chart showing an example of detailed operation flow performed by the optical information recording/reproducing apparatus during data reproduction.
FIGS. 6A-6G show examples of encoding method performed by the optical information recording/reproducing apparatus.
FIG. 7 is a flow chart showing an example of detailed operation flow performed by the optical information recording/reproducing apparatus during data recording.
FIG. 8 is a flow chart showing an example of detailed operation flow performed by the optical information recording/reproducing apparatus during data reproduction.
FIGS. 9A-9F show examples of encoding methods performed by the optical information recording/reproducing apparatus.
FIG. 10 is a flow chart showing an example of detailed operation flow performed by the optical information recording/reproducing apparatus during data recording.
FIGS. 11A and 11B show examples of modulation performed by the optical information recording/reproducing apparatus.
FIGS. 12A-12C show examples of conventional encoding methods performed by the optical information recording/reproducing apparatus.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Now, embodiments of this invention will be described below.
Embodiment 1
FIG. 1 shows an overall configuration of the optical information recording/reproducing apparatus to record and/or reproduce digital information by using holography.
The optical information recording/reproducing apparatus 10 has a pickup 11 , a phase conjugate optical system 12 , a disc-cure optical system 13 , a disc rotation angle detecting optical system 14 and a rotating motor 50 . The optical information recording medium 1 can be turned by the rotating motor 50 .
The pickup 11 emits a reference beam and a signal beam to the optical information recording medium 1 to record digital information by using holography.
At this time, the information signal to be recorded is sent by a controller 89 through a signal generation circuit 86 to a spatial light modulator described later in the pickup 11 where the signal beam is modulated by the spatial light modulator.
When the recorded information in the optical information recording medium 1 is reproduced, a phase conjugate beam of the reference beam emitted from the pickup 11 is generated by the phase conjugate optical system 12 . The phase conjugate beam is a light wave that propagates in a direction opposite the incident light while keeping the same wave plane. A light reproduced by the phase conjugate beam is detected by an optical detector described later in the pickup 11 and is processed by a signal processing circuit 85 to reproduce the signal.
The time during which the reference beam and the signal beam are irradiated to the optical information recording medium 1 can be adjusted by controlling a shutter open-close time described later by the controller 89 through a shutter control circuit 87 .
The disc-cure optical system 13 has a function of generating an optical beam used for pre-curing and post-curing the optical information recording medium 1 . The pre-cure means a step of preliminarily applying a predetermined optical beam before irradiating the reference beam and the signal beam to a desired position when recording information at the position of interest in the optical information recording medium 1 . The post-cure means is a step of applying a predetermined optical beam after having recorded information at a desired position in the optical information recording medium 1 in order to make the desired position unrecordable.
The disc rotation angle detecting optical system 14 is used to detect a rotation angle of the optical information recording medium 1 . Adjusting the optical information recording medium 1 to a predetermined rotation angle can be done by detecting a signal corresponding to the rotation angle by the disc rotation angle detecting optical system 14 and controlling the rotation angle of the optical information recording medium 1 by the controller 89 using the detected signal through a disc rotating motor control circuit 88 .
A light source drive circuit 82 supplies a predetermined amount of light source drive current to light sources inside the pickup 11 , the disc-cure optical system 13 and the disc rotation angle detecting optical system 14 , so that these light sources can emit light beams of a predetermined light quantity.
The pickup 11 , the phase conjugate optical system 12 and the disc-cure optical system 13 are each provided with a mechanism that allows them to slide in a radial direction of the optical information recording medium 1 . So their positions are controlled by these mechanisms through an access control circuit 81 .
The recording technology using holography can record information of ultrahigh density and therefore tends to have very small allowable errors with respect to variations in inclination and position of the optical information recording medium 1 . So a servo mechanism may be provided in the optical information recording/reproducing apparatus 10 to correct variations of, for example, inclination and position of the optical information recording medium 1 , for which allowable errors are very small, through a servo control circuit 84 by installing a device in the pickup 11 to detect these variations and by generating a servo control signal in a servo signal generation circuit 83 .
The pickup 11 , the phase conjugate optical system 12 , the disc-cure optical system 13 and the disc rotation angle detecting optical system 14 may be arranged commonly for some optical systems or all of the optical systems for simplification.
FIG. 2 shows an example configuration of the optical system for the pickup 11 in the optical information recording/reproducing apparatus 10 .
A light beam emitted from the light source 301 passes through a collimate lens 302 and enters into a shutter 303 . When the shutter 303 is open, the light beam passes through it and is controlled in its polarization direction by an optical element 304 constructed of ½ waveplate so that a ratio between P-polarization and S-polarization is a desired one. Then the beam enters a PBS (Polarization Beam Splitter) prism 305 .
The light beam that has passed through the PBS prism 305 is expanded in its diameter by a beam expander 309 , before passing through a phase mask 311 , a relay lens 310 and a PBS prism 307 and entering into a spatial light modulator 308 .
The signal beam that was given information by the spatial light modulator 308 passes through the PBS prism 307 and then travels through a relay lens 312 and a spatial filter 313 . Then, the signal beam is focused by an object lens 325 onto the optical information recording medium 1 .
A light beam reflected by the PBS prism 305 works as a reference beam. After being set in a predetermined polarization direction by a polarization direction conversion element 324 depending on whether the operation is being performed for recording or for reproduction, the beam passes through a mirror 314 and a mirror 315 and enters into a galvanometer mirror 316 . The galvanometer mirror 316 , since it adjusts its angle by an actuator 317 , can set to a desired angle the incident angle of the reference beam entering into the optical information recording medium 1 after passing through a lens 319 and a 320 .
By having the signal beam and the reference beam overlap each other in the optical information recording medium 1 as described above, interference patterns are formed in the recording medium and then written into the recording medium to record the information. Further, since the incidence angle of the reference beam entering the optical information recording medium 1 can be changed by the galvanometer mirror 316 , the angle multiplexing-based recording can be performed.
In reproducing the recorded information, the reference beam is applied to the optical information recording medium 1 . The light beam that has passed through the optical information recording medium 1 is reflected by a galvanometer mirror 321 to generate a phase conjugate beam.
The reproduced light beam generated by this phase conjugate beam propagates through the object lens 325 , the relay lens 312 and the spatial filter 313 . Then, the reproduced light beam is reflected by the PBS prism 307 and enters into an optical detector 318 to reproduce the recorded signal.
The optical system configuration of the pickup 11 is not limited to FIG. 2 .
FIGS. 3A-3C show the operation flow for the recording and reproduction in the optical information recording/reproducing apparatus 10 . Here, a recording and reproduction flow using holography will be explained.
FIG. 3A shows an operation flow from the optical information recording medium 1 being inserted into the optical information recording/reproducing apparatus 10 until the recording or reproduction is ready. FIG. 3B shows an operation flow from the standby state until the information is recorded in the optical information recording medium 1 . FIG. 3C shows an operation flow from the standby state until the information recorded in the optical information recording medium 1 is reproduced.
When a medium is inserted (S 301 ) as shown in FIG. 3A , the optical information recording/reproducing apparatus 10 makes a disc check to see if the inserted medium is intended for recording or reproducing digital information using holography (S 302 ).
If the disc check result finds that the disc is intended to record or reproduce digital information using holography, the optical information recording/reproducing apparatus 10 reads control data for the optical information recording medium and retrieves, for example, information about the optical information recording medium and information about various setting conditions for recording or reproduction (S 303 ).
After the control data has been read out, the optical information recording/reproducing apparatus 10 makes various adjustments according to the control data and executes learning processing concerning the pickup 11 (S 304 ). Now the optical information recording/reproducing apparatus 10 is ready for recording or reproduction (S 305 ).
The operation flow from the standby state to the recording of information, as shown in FIG. 3B , involves receiving data to be recorded and sending information corresponding to the data to the spatial light modulator in the pickup 11 (S 306 ).
Then, to record high quality information in the optical information recording medium, various learning processing is executed in advance as required (S 307 ) and, at the same time, seek operation (S 308 ) and address regeneration (S 309 ) are repeated to put the pickup 11 and the disc-cure optical system 13 at a predetermined position on the optical information recording medium.
Then, a light beam emitted from the disc-cure optical system 13 is applied to the medium to pre-cure a predetermined area (S 310 ). The reference beam and the signal beam emitted from the pickup 11 are used to record data (S 311 ).
After the data is recorded, the data is verified as necessary (S 312 ) and the light beam emitted from the disc-cure optical system 13 is used for post-curing (S 313 ).
In the operation flow from the standby state to the reproduction of the recorded information, as shown in FIG. 3C , various learning processing is executed as necessary in advance (S 314 ). Then, the seek operation (S 315 ) and the address regeneration (S 316 ) are repeated to put the pickup 11 and the phase conjugate optical system 12 at a predetermined position on the optical information recording medium.
After this, the reference beam is emitted from the pickup 11 to read information recorded in the optical information recording medium (S 317 ).
The encoding method in this example will be described in detail by referring to FIG. 4 , FIG. 5 and FIGS. 6A-6G .
FIG. 4 shows a detailed operation flow of S 306 in FIG. 3B . FIG. 5 shows a detailed operation flow of S 317 in FIG. 3C . FIGS. 6A-6G show examples of processing.
First, detailed operations during recording will be explained. When the signal generation circuit 86 receives one page of recording data (S 401 ) ( FIG. 6A ), it modulates data strings by using a modulation table (S 402 ). This modulation is done to facilitate detection of data during reproduction by preventing the same data “0” or “1” from repeating continuously and also to control spatial frequency characteristics of patterns to be finally recorded. This modulation, however, may not be performed. Next, the modulated data is divided into units of N bits, to each of which one control bit is added (S 403 ) ( FIG. 6B ). The control bit is determined to be “0” or “1” according to a method described below. First, let us assume that a control bit at a certain position is “0” (S 404 ). An NRZI (None Return to Zero Inverted) modulation is performed on a data string up to the next control bit. This modulation leaves the value unchanged if the bit is “0” and inverts the value if it is “1” (S 405 ). Unlike the NRZI modulated data, a DSV (Digital Sum Value), which is an accumulated value of 1 in the data string taken as +1 and 0 as −1, is calculated up to the next control bit (S 406 ). To make the value of page data constant among different pages, it is desired that the DSV be a sum value not only for the data string between the control bits but also for the data following the entire NRZI modulation up to the control bit. Next, when the control bit is assumed to be “1”, operations similar to S 404 , S 405 and S 406 are also executed. Here, the DSVs calculated in S 406 to S 409 are compared to determine the control bit added in S 403 to make DSV close to 0 (S 410 ) ( FIG. 6C ). These operations from S 404 to S 410 are repeated (S 411 ) to determine all the added control bits. On the data strings for which control bits were determined, the NRZI modulation is performed to generate data strings to be recorded (S 412 ) ( FIG. 6D ).
Then, two-dimensional data is constructed as shown in FIG. 6E , with “0” taken as “non-transmissive” and “1” as “transmissive” (they may be reverse). For each unit to which a control bit is inserted, an area of n (vertical)×m (horizontal) pixels is set ( 601 , 602 , 603 , 604 ) and bits are arranged there. This bit arrangement for each unit is repeated the same number of times as a page of data to create one page of 2-dimensional data (S 413 ). In the example of FIG. 6F , the bit arrangement in the unit and the unit arrangement in the page are done by placing data beginning with the upper left and moving toward right and, when the right end is reached, moving one line down and then toward right. The data arrangement is not limited to this method. FIG. 6G shows an example configuration where n=1.
A marker that works as a reference during reproduction is added to the 2-dimensional data constructed as described above (S 414 ). The data marked in this way is transferred to the spatial light modulator 308 (S 415 ).
Next, a detailed operation during reproduction will be explained. First, image data retrieved from the optical detector 318 is transferred to the signal processing circuit 85 (S 501 ). The image position is detected with an image marker taken as a reference (S 502 ). The image data undergoes a distortion correction, including image inclination, magnification and distortion (S 503 ). The corrected image is then subjected to a binarization operation (S 504 ) and removed of markers (S 505 ) to obtain 2-dimensional data (S 506 ). Although the binarization generally employs a method of comparing adjoining bits, other methods may be employed. By reversing the recording procedure, the 2-dimensional data is rearranged into 1-dimensional data, which then undergoes the NRZI modulation (S 507 ). The data is removed of the added control bits (S 508 ) and demodulated into the original data strings by using the modulation table used for recording, thus reproducing the original data (S 509 ) (S 510 ).
The explained drive construction and operation are just one example and this invention can employ other constructions and can be applied not only to the angle-multiplexing method but also to the shift multiplexing method. The same is true of the following embodiments.
With the above operation, 2-dimensional data can be created whose ratios of transmissive and non-transmissive bits are always even in the entire page data although they may differ among different units. This in turn allows the data to be recorded with the transmissivity kept constant among pages. During recording, a signal beam modulated by the spatial light modulator 308 is focused by the object lens 325 onto the recording medium, so a Fourier-transformed image is recorded. This means that if the transmissivity of created 2-dimensional data differs among different units, the recording medium is not affected.
Embodiment 2
The second embodiment differs from embodiment 1 in the 2-mensional data generation method of S 306 and the data reproducing method of S 317 . FIG. 7 shows a detailed operation flow of S 306 in FIG. 3B . FIG. 8 shows a detailed operation flow of S 317 in FIG. 3C . FIGS. 9A-9F show examples of processing.
First, a detailed operation during recording will be explained. When the signal generation circuit 86 receives one page of recording data (S 701 ) ( FIG. 9A ), it modulates data strings by using a modulation table (S 702 ). Next, the data is divided into units of N bits, to each of which a control bit is added (S 703 ) ( FIG. 9B ). The control bit is one bit in this embodiment but may be multiple bits. First, assuming that a control bit at a certain position is “0” (S 704 ), a DSV up to the next control bit is calculated (S 705 ). It is desired that the DSV be a sum value not only for the data between the control bits but also for all data up to that control bit. Next, when the control bit is assumed to be “1” (S 706 ), an inversion operation of inverting “0” to “1” and “1” to “0” is executed on data strings up to the next control bit (S 707 ). The inverted data strings are used to calculate a DSV up to the next control bit (S 708 ). This data inversion may be performed commonly for several bits by using a table. The DSVs calculated by S 705 and S 708 are compared to determine a control bit added to make the DSV close to 0 (S 709 ). The operations from S 704 to S 709 are repeated (S 710 ) to determine all the control bits added in S 703 . The data strings to which this control bit was added are subjected to the inversion operation for each unit according to the control bit to generate the data strings to be recorded (S 711 ) ( FIG. 9C ).
After this, 2-dimensional data is constructed as shown in FIG. 9D , with “0” taken as non-transmissive and “1” as transmissive (they may be opposite). For each unit to which a control bit is inserted, an area of n (vertical)×m (horizontal) pixels is set ( 901 , 902 , 903 , 904 ) and bits are arranged there. This bit arrangement for each unit is repeated the same number of times as a page of data to create one page of 2-dimensional data (S 712 ). In the example of FIG. 9E , the bit arrangement in the unit and the unit arrangement in the page are done by placing data beginning with the upper left and moving toward right and, when the right end is reached, moving one line down and then toward right. The data arrangement is not limited to this method. FIG. 9F shows an example configuration where n=1.
The 2-dimensional data constructed as described above is attached with a marker that works as a reference during reproduction (S 713 ). The data marked in this way is transferred to the spatial light modulator 308 (S 714 ).
Next, a detailed operation during reproduction will be explained. First, image data retrieved from the optical detector 318 is transferred to the signal processing circuit 85 (S 801 ). The image position is detected with an image marker taken as a reference (S 802 ). The image data undergoes a distortion correction, including image inclination, magnification and distortion (S 803 ). The corrected image is then subjected to a binarization operation (S 804 ) and removed of markers (S 805 ) to obtain 2-dimensional data (S 806 ). Although the binarization generally employs a method of comparing adjoining bits, other methods may be employed. By reversing the recording procedure, the 2-dimensional data is rearranged into 1-dimensional data, which is then inverted for each unit (S 807 ). The inverted data is removed of the added control bits (S 808 ) and demodulated into the original data strings by using the modulation table used for recording, thus reproducing the original data ( 8509 ) (S 810 ).
With the above operation, 2-dimensional data can be created whose ratios of transmissive and non-transmissive bits are always even in the entire page data although they may differ among different units. This in turn allows the data to be recorded with the transmissivity kept constant among pages. During recording, a signal beam modulated by the spatial light modulator 308 is focused on the recording medium by the object lens 325 , so a Fourier-transformed image is recorded. This means that if the transmissivity of created 2-dimensional data differs among different units, the recording medium is not affected.
Unlike embodiment 1, this embodiment does not perform such operations as NRZI modulation and thus can record data at high speed. It is noted, however, that since the data inversion depends on the control bits, the reading of the control bits becomes important as shown in FIG. 9E ( 905 , 906 , 907 , 908 ). It is therefore effective to represent the control bit with multiple bits, as described above, add error correction codes or placing data at a central area of the page where reading errors are not likely to occur.
Embodiment 3
This embodiment differs from embodiment 1 in the control bit determination rule in S 410 . In embodiment 1, the DSVs calculated from S 406 to S 409 are compared and the control bit added in S 403 is determined so as to make the DSV close to 0 (S 410 ). In this embodiment, the control bit is determined so as to make the DSV close to a preset target value (S 1010 ).
Further, to make it easy to shift the DSV in a certain direction, it is useful to modulate the data in advance so as to make the ratios of “0” and “1” of the NRZI-modulated data uneven. For example, in the modulation operation of S 1002 in FIG. 10 , the modulation is executed using a modulation table such as one shown in FIG. 11A . This operation is characterized in that the modulated data has “1” appear the even number of times, which, when the data is NRZI-modulated, makes the frequencies of appearance of “0” and “1” differ. Although the use of this table renders the ratio of “0” and “1” uneven, the method of modulation is not limited to this table and other methods may be used as long as they can change the ratio of “0” and “1”. While this table performs a modulation from 2-bits to 3 bits, other bit numbers may be used.
The above method can similarly applied also to embodiment 2. It is noted, however, that since embodiment 2 does not perform the NRZI modulation, it is useful to make a greater number of “0s” (or “1s”) appear in the data modulated by S 1002 . For example, in the modulation operation S 1002 of FIG. 10 , a modulation table, such as shown in FIG. 11B , is used. Although the use of this table can render the ratio of “0” and 1” uneven, the modulation method is not limited to this table and other methods may be used as long as they can change the ratio of “0” and “1”. While this table performs a modulation from 2 bits to 3 bits, other bit numbers may be used.
With the above operation, 2-dimensional data can be created whose ratio of transmissive and non-transmissive bits are always even in the entire page data although they may differ among different units. This allows the data to be recorded so that the transmissivity is kept constant among different pages. During recording, a signal beam modulated by the spatial light modulator 308 is focused on the recording medium by the object lens 325 , so a Fourier-transformed image is recorded. This means that if the transmissivity of created 2-dimensional data differs among different units, the recording medium is not easily affected.
Further, in embodiment 1 since the ratio of “0” and “1” are equal, the transmissivity in one page can be set only at 50% by the spatial light modulator 308 . In contrast to embodiment 1, this embodiment is characterized by the ability to set an arbitrary transmissivity. For example, the transmissivity can be made small by first setting the DSV target value at a negative value to make the ratio or frequency of “0” high, determining the control bit and then creating the 2-dimensional data with “0” taken as non-transmissive bit. This suppresses the consumption of a dynamic range of the medium, the level of multiplexing can be raised. Further, depending on the content of data, the advantage of this embodiment can be realized by setting the ratio of “0” and “1” within a predetermined range (e.g., 45%-55%). This in turn reduces loads during recording. What is described here also applies to other embodiments.
It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.
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An optical information recording/reproducing apparatus using holography comprises a signal generation unit that modulates input data, adds at least one control bit to each group of N bits, performs an NRZI-modulation on the modulated data, determines the at least one control bit such that a digital sum value of the NRZI-modulated data is 0, performs NRZI modulation on the data whose at least one control bit was determined, and rearranges the data to generate 2-dimensional data; a pickup that records the 2-dimensional data in a hologram disc and reproduces the 2-dimensional data from the hologram disc; and a signal processing unit that corrects the 2-dimensional data reproduced by the pickup, performs NRZI-modulation on the 2-dimensional data that has undergone a binarization operation, removes the at least one control bit added during the recording, and demodulates the data according to a modulation rule used during the recording.
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FIELD OF TECHNOLOGY
[0001] The present invention describes a method of production of metal carboxylates, concretely butyrates and formates of divalent metals, as well as their carboxylate-aminoate or carboxylate-methioninate hydroxy analog derivatives of divalent metals, for use as trace metal supplement in animal feed.
BACKGROUND OF THE INVENTION
[0002] There are at present two subjects of vital importance in the legal framework of the animal production sector: the use of antibiotics that are growth promoters and the emission of residues to the environment, of the trace elements necessary both for promoting said growth and incorporated in feed.
[0003] Regarding growth-promoter antibiotics, these display great efficacy for improving production yields and preventing certain diseases, so that for more than 50 years they have made it possible to reduce production costs considerably. However, owing to the controversy concerning the possible development of resistance in certain strains of bacteria and its consequences for public health, in March 2002 the Committee of the European Union proposed a ban on these additives, which will be applied starting from 2005. Considerable repercussions are to be expected in the animal production sector, owing to the large increase in the costs of production.
[0004] In the case of trace elements, the considerable genetic improvement and physical development of production animals have led to an increase in demand for these nutrients to satisfy the requirements and ensure optimum development. In this sense, however, waste disposal is increasingly being regulated by legislation and the maximum permitted levels for inclusion in feed are steadily decreasing. Therefore recourse is being had increasingly to new sources of minerals (organic sources of minerals) with greater bioavailability and, accordingly, less likely to be eliminated in the feces. It should be pointed out that some inorganic sources of minerals, such as copper sulfate and zinc oxide, when administered at high doses (250 ppm and 1500-3000 ppm respectively) produce a considerable growth-promoter effect, mainly through their bactericidal action in the intestine, but said doses are far higher than those laid down by the environmental legislation (175 and 250 ppm for copper and zinc, respectively), therefore we must also do without their benefits.
[0005] That is why in recent years the animal feed additives industry has devoted considerable effort to the development of new substances to replace growth-promoting antibiotics without posing a health risk, and to the search for organic sources of minerals that provide the levels required for optimum growth of the animal and greatly reduce the discharge of residues into the environment.
[0006] Organic acids have proved very effective as intestinal sanitizing agents and improvers of production parameters in livestock and they therefore represent one of the most suitable alternatives to growth-promoting antibiotics. Among them, formic acid and butyric acid can be regarded as the most effective in monogastric animals owing to their recognized bactericidal effect and growth stimulation of the intestinal villi, which improve intestinal integrity and increase the absorption of nutrients. Supplements of iron (Fe) in the diet of livestock, by means of formate (WO 99/62355), or supplements of chromium (Cr +6 ) or manganese (Mn +7 ), by means of propionates (WO 98/33398), are known in this context.
[0007] The organic sources of minerals available as supplements for animal nutrition comprise:
Metal chelates with amino acids: molar ratio from 1:1 to 1:3. Metal/amino acid complexes: formed by covalent bonding of an (unspecified) amino acid and a metal. Complexes of specific amino acids with a metal: constituted of a specific amino acid and a metal. Proteinates: resulting from the chelation of a hydrolyzed protein with a metal. Polysaccharide/metal complexes. Metal carboxylates: salts of various carboxylic acids with divalent metals. Used for the most part as organic mineral supplements, with greater bioavailability than the inorganic sources.
[0014] Against this background, one of the objects of the present invention relates to the production of combined molecules of organic acids of recognized efficacy in animal production, concretely formic and butyric acids, and inorganic salts of zinc and copper. This combination displays a synergistic effect which boosts the effectiveness of both substances in improving the production parameters and increases the bioavailability of the metals, permitting the use of copper and zinc as promoter substances, but keeping their level of inclusion in the feed within the established legal limits.
[0015] Another object of the present invention is the production of derivatives of the aforementioned metal carboxylates which are carboxylate-aminoates of divalent metals or carboxylate-methioninate hydroxy analogs of divalent metals. This combination displays an even greater synergistic effect which boosts the effectiveness of these substances in improving the production parameters and increases the bioavailability of the metals, further facilitating the use of divalent metals as promoters, but keeping their level of inclusion in the feed within the established legal limits.
[0016] Another object of the present invention is to develop a method of production, both of metal carboxylates and of their metal carboxylate-aminoate or carboxylate-methioninate hydroxy analog derivatives, as an alternative to the conventional methods of synthesis in an aqueous medium that require the separation of the precipitated product from the solution and drying of said product.
[0017] A further object of the present invention is the use of the products obtained (metal carboxylates and their metal carboxylate-aminoate or metal carboxylate-methioninate hydroxy analog derivatives) as additives in the feed of monogastric production animals, with the aim of improving their productivity.
[0018] An advantage of the process described, relative to the conventional method in aqueous solution, is that it reduces the number of stages in the production process considerably, since operations such as product precipitation or filtration are avoided. Another advantage of this invention is that it provides a process for the production of carboxylates of divalent metals that is easy to implement on a large scale and at low cost since the process requires relatively low energy consumption. Furthermore, this method of production offers the additional advantage over the conventional method, that in some cases it increases the solubility with respect to some basic metal compounds. Yet another advantage of the invention is that an organic source of metal is obtained with a higher metal content.
[0019] Regarding its application, the compounds described in this specification have the advantage that their obvious growth-promoting effect in monogastric animals improves the production parameters, increasing the bioavailability of the metals and therefore reducing their emission to the environment.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The present invention describes a method for the production of carboxylates (C 1 , C 4 ) of divalent metals that correspond to the formula M(RCOO) 2 , where M is the zinc (Zn 2+ ) or copper (Cu 2+ ) divalent metal cation and R corresponds to a proton for the formates and to the CH 3 (CH 2 ) 2 group for the butyrates, and of their metal carboxylate-aminoate or metal carboxylate-methioninate hydroxy analog derivatives. The source of metal cation, M, in the case of the carboxylates and the methioninate hydroxy analogs is a basic compound of the metal such as oxide or hydroxide, concretely zinc(II) oxide and copper(II) hydroxide, and in the case of the aminoates the source of cation used is metal salts, such as zinc sulfate and copper sulfate and in the derivatives, in the carboxylate-aminoate derivatives a combination of the aforementioned sources of metal is used.
[0021] The carboxylates of divalent metal are prepared starting from the carboxylic acid by addition of the dry basic salt of the divalent metal, oxide of Zn 2+ or hydroxide of Cu 2+ , without needing to add any kind of solvent. This is an advantage since the basic salts of the metals used in the present invention are sparingly soluble in water. The reactants are stirred together, giving rise to an exothermic reaction which produces water and the carboxylate of Zn(II) or Cu(II). The reaction mixture is stirred further in order to eliminate the water formed, so that the formate or butyrate is obtained dry and water-free.
[0022] Formation of the metal carboxylate-aminoates begins with a stage of preparation of the metal aminoate. Said compound is prepared from the amino acid and the metal compound; water is added to the amino acid, and between 0.1% and 0.3% of soda is added as neutralizing agent if required. The water is virtually eliminated by a vacuum drying process. The reaction mixture is kept stirred with the water at 90-98° C. for 20 min or longer, depending on the actual type of aminoate to be obtained, with the aim of obtaining the desired aminoate. Next the metal aminoate obtained is mixed with the metal carboxylate, subjecting the product to a process at temperature of 90-98° C. or to a vacuum process at lower temperature, depending on the product, to obtain the corresponding final product, adding absorbent if required.
[0023] The carboxylate-methioninate hydroxy analogs of divalent metal are prepared from the mixture of carboxylic acid and methionine hydroxy analog and addition of basic compound of divalent metal, without the need to add any type of solvent. The acid mixture is added slowly, stirring continuously, resulting in an exothermic reaction that produces water and a mixture of carboxylate-methioninate hydroxy analog of divalent metal. The reaction mixture is stirred further at a temperature of 90-98° C. or in vacuum at a lower temperature, for the purpose of removing practically all of the water formed, obtaining the dry carboxylate-methioninate hydroxy analog.
[0024] The butyric or formic acid and the basic compound of divalent metal are used in approximately stoichiometric quantities, with a molar ratio of carboxylic acid and metallic base of approximately 2:1, it being possible to work with an excess of 3-6 wt. %, both of the metal compound and of the carboxylic acid.
[0025] The amino acid and the metal compound are used in 1:1 molar ratio, working with excess of metal (1-3 wt. %).
[0026] The methionine hydroxy analog and the metal compound are used in 2:1 molar ratio, working with excess of metal (1-3 wt. %).
[0027] The formic acid used in the invention contains 15% water. The butyric acid contains 0.016% water. The methionine hydroxy analog contains 11.20% water. Glycine and methionine can be regarded as anhydrous reactants.
[0028] The commercially available metallic bases that are used do not contain water of crystallization, but the sulfates do. It is preferable to use these bases in the form of relatively small particles (particle size below 6.5 mm) to facilitate contact between the reactants and subsequent reaction.
[0029] Butyric acid melts at −7.9° C. and boils at 163.5° C. at 1 atm. Butyric acid forms an azeotrope with water which boils at 99.4° C. and contains 18.4% of butyric acid. As a result of formation of the azeotrope and the relatively low boiling point of the mixture, some of the butyric acid is lost with the water at the reaction temperature, and is recovered in the process by means of condensation and combination of soluble sodium salts or calcium salts that can be precipitated. Formic acid melts at 8.4° C. and boils at 100.5° C. at 1 atm. Formic acid forms an azeotrope with water which boils at 107.1° C. and contains 77.5% of formic acid. As a result of formation of the azeotrope and the relatively low boiling point of the mixture, some of the formic acid is lost with the water at the reaction temperature, and is recovered in the process by means of condensation and combination of soluble sodium salts or calcium salts that can be precipitated.
[0030] Both butyric acid and formic acid are used in liquid form.
[0031] Any reactor or equipment can be used for carrying out the reaction. In the case of small-scale reactions in the laboratory, a beaker was used as the reactor and a rod as the stirrer. For large-scale preparation, it is preferable to use a mixer equipped with mass stirrers and a lump-disintegrating intensifier turbine. After stirring, the reaction is completed in minutes but it is best to leave it to cool and dry for approximately one hour.
[0032] Reaction takes place exothermically according to the following equations:
[0033] Reaction of the metal salts:
1) Zn(II) butyrate: ZnO+2CH 3 (CH 2 ) 2 COOH→Zn(CH 3 (CH 2 ) 2 COO) 2 +H 2 O 2) Cu(II) butyrate: Cu(OH) 2 +2CH 3 (CH 2 ) 2 COOH→Cu(CH 3 (CH 2 ) 2 COO) 2 +2H 2 O 3) Zn(II) formate: ZnO+2HCOOH→Zn(HCOO) 2 +H 2 O 4) Cu(II) formate: Cu(OH) 2 +2HCOOH→Cu(HCOO) 2 +2H 2 O 5) Metal methioninate hydroxy analog: 2HMA+ZnO=Zn(MA) 2 +H 2 O 6) Metal methioninate hydroxy analog: 2HMA+Cu(OH) 2 =Cu(MA) 2 +H 2 O
[0040] Reaction of formation of chelates:
1) Metal amino acid: Amino acid (e.g. glycine)+Source of metal=MAm
[0042] When the carboxylic acid and the basic metal compound react there is evolution of water and heat. The water and a proportion of the acid are eliminated continuously from the reaction medium by the heat of reaction, continuous stirring of the product and/or a vacuum cleaning system.
[0043] In the preparation of zinc formate, the heat of reaction is sufficient to evaporate the water that forms. In the preparation of zinc butyrate, copper butyrate and copper formate it is necessary to assist this by supplying additional heat.
[0044] The result is a dry product in the form of powder in the case of the butyrates. Both zinc formate and copper formate are obtained as large particles which require grinding.
[0045] The divalent metal carboxylates prepared by this process are obtained at yields of around 80%, although values of 90% may be reached. Losses are recovered by means of a gas recovery system with condensers and combination with soluble sodium salts or calcium salts that can be precipitated. The products are obtained in the form of dry powder but may form lumps owing to the presence of small amounts of unreacted acid. In these cases it is preferable to employ grinding to obtain a product that could be used directly as a feed supplement. This production process avoids post-reaction treatments such as, among others: concentration, crystallization, separation by filtration, decanting or centrifugation and freeze-drying, which requires the conventional aqueous method, saving energy and costs.
[0046] In the case of the carboxylate-aminoates, the solution thickens in the preceding stage of formation of the aminoate from the amino acid and the salt in aqueous medium. The compound obtained is mixed with the metal carboxylate described previously and the water is removed by means of the vacuum cleaning system with addition of silica if appropriate.
[0047] In the case of formation of the carboxylate-methioninate hydroxy analog, when the basic metal compound is added to the mixture of carboxylic acid and hydroxy analog of methionine, water and heat are generated. The water is eliminated continuously from the reaction medium by the heat of reaction and continuous stirring of the product and/or vacuum cleaning system.
[0000] Examples of Manufacture of Metal Carboxylates
[0000] Processes at the Laboratory Scale
EXAMPLE 1
Zinc butyrate
[0048] Zinc butyrate was prepared by adding 20.25 g of ZnO to 44 g of butyric acid, in a beaker (stoichiometric proportions ZnO:butyric acid 1:2). The reactants were mixed rapidly by stirring with a glass rod, allowing the vapors formed to escape from the beaker. The reaction reached a temperature of 55° C. After stirring for 5 minutes, the product is obtained as a moist white solid which is passed through a cooling screw or at room temperature which removes it to dry it more quickly and make it available for grinding to the granulometry required for marketing. A product with more than 90% of zinc butyrate was obtained.
EXAMPLE 2
Copper butyrate
[0049] Copper butyrate was prepared by adding 26.5 g of Cu(OH) 2 to 44 g of butyric acid, in a beaker (proportions Cu(OH) 2 :butyric acid 1.1:2). The reactants were mixed rapidly, stirring with a glass rod and allowing the vapors that form to escape from the beaker. The reaction reached a temperature of 65° C. After stirring for 5 minutes, the product is obtained in the form of a moist greenish-blue solid which is passed through a cooling screw or at room temperature which removes it to dry it more quickly and make it available for grinding to the granulometry required for marketing. A product with more than 90% of copper butyrate was obtained.
EXAMPLE 3
Zinc formate
[0050] Zinc formate was prepared by adding 21.75 g of ZnO to 27 g of formic acid (85%), in a beaker (proportions ZnO:formic acid 1.1:2). The reactants were mixed rapidly, stirring with a glass rod and allowing the vapors that form to escape from the beaker. The highly exothermic reaction reached a temperature of 120° C. After stirring for 5 minutes, the product is obtained in the form of a moist white solid which is passed through a cooling screw or at room temperature which removes it to dry it more quickly and make it available for grinding to the granulometry required for marketing. A product with more than 85% of zinc formate was obtained. Final grinding of the product is required.
EXAMPLE 4
Copper formate
[0051] Copper formate was prepared by adding 24.5 g of Cu(OH) 2 to 27 g of formic acid (85%), in a beaker (stoichiometric proportions Cu(OH) 2 :formic acid 1:2). The reactants were mixed rapidly, stirring with a glass rod and allowing the vapors that form to escape from the beaker. The reaction reached a temperature of 65° C. After stirring for 5 minutes, the product is obtained in the form of a fairly moist blue solid which is passed through a cooling screw or at room temperature which removes it to dry it more quickly and make it available for grinding to the granulometry required for marketing. A product with more than 85% of copper formate was obtained. Final grinding of the product is required.
[0052] When working in the laboratory it is preferable to separate the water produced in the reaction in the form of steam but in large-scale operation it can be aspirated from the exothermic reaction mixture under reduced pressure (vacuum). It is preferable to use a well insulated mixer in order to retain the heat that is released by the reaction and evaporate the water from the product.
[0000] Processes on an Industrial Scale
[0053] Operation on an industrial scale employs a first reactor-mixer (stirred tank reactor, STR) with a double-saw flat-disk agitator of the Cowles type from 1500 to 3000 rpm, connected via a discharge outlet with a sluice gate or gate valve to reactor plant (MHT 1200). This discharge outlet comprises a hermetic closure system with pneumatic operation to permit fast discharge from the reactor. The second reactor comprises blades of the plow type, mass agitators from 200 to 400 rpm and two intensifier/delumping turbines from 1500 to 3000 rpm. The reactor also comprises a double jacket with hot oil or preferably steam, at a temperature from 80 to 130° C. (preferably between 90 and 110° C.). Apart from the movement of the agitator blades, the equipment comprises vacuum by means of a cyclone-aspirator in line, passing said aspirated material firstly through a bag filter which separates the solids from the vapors produced by the reaction and, secondly, the vapor from which the solids have already been removed is directed into a condensing heat exchanger, recovering the water of reaction with some acid (1-2%) for later treatment. Lastly, the remaining vapor passes through a gas scrubber, with dissolution of NaOH at 25% for neutralizing the acidic vapors produced. A negative-pressure sealed enclosure is used, collecting all the vapors to be treated, avoiding emission of harmful vapors to the exterior (bad odors). In conclusion, both the water of reaction and any vapor remain perfectly controlled and clean, for use in this process itself or in other processes. Separate machines are used, one for the products containing zinc and another for the copper products.
[0054] From the stainless steel storage tanks (INOX AISI-304L) which receive the carboxylic acid, the required amount of acid is injected into the first reactor with a magnetic proportioner. At the same time as the carboxylic acid, the basic compound of divalent metal is added by means of a proportioner with load cells, keeping the mixture stirred for a time of from 2 to 30 seconds. After this time, the discharge outlet with sluice valve that separates the two reactors is opened and the reaction mixture is allowed to descend to the second reactor, where stirring continues for between 1 and 5 minutes with the plow-type blades, operating at between 200 and 600 rpm and the intensifier turbines between 1500 and 3000 rpm.
[0055] On completion of reaction, the equipment is sealed and the vacuum is switched on, which will draw off, in the form of steam, the water molecules produced in the same reaction together with some of the acid (between 1 and 2%). To complete this extraction more immediately, the intensifier turbines are operated at between 1500 and 3000 rpm and will break up any lumps and ensure faster release of moisture from the particles, assisted by the heat of reaction and the heat of the double jacket with hot oil or preferably steam between 80 and 130° C. Total process time is between 20 and 70 minutes.
EXAMPLE 5
Copper butyrate, on an Industrial Scale
[0056] 200 kg of copper butyrate was prepared in the equipment described previously. Firstly the first reactor was charged with 140 kg of butyric acid and 85 kg of Cu(OH) 2 , stirring with the double-saw flat-disk agitator at 2000 rpm for 30 s. After this time, the discharge outlet with sluice valve was opened, allowing the product to descend to the second reactor, where it was stirred for 2 minutes with the plow-type blades at 400 rpm and the intensifier turbines at 2000 rpm. Then the discharge outlet was closed, the vacuum was switched on to draw off the steam produced and the intensifier turbine was switched on at 2000 rpm to break up the lumps that had formed and assist in removal of the water. The reaction temperature is 65° C., so it was necessary to help with the double jacket of hot oil or preferably steam, at 120° C. to obtain a dry greenish-blue product in powder form. The total losses in the reaction are 11%, with a loss of butyric acid of 1.3% and with a product purity of more than 90%. Total process time was approximately 50 minutes.
[0000] Examples of Manufacture of Metal Carboxylate-aminoates
[0057] For preparation of metal carboxylate-aminoates on an industrial scale, the method is changed as follows: The second reactor of the Lödige type is loaded with the basic metal compound by means of a proportioner with load cells or other metering system. From the stainless steel storage tanks (INOX AISI-403L) where the carboxylic acid is received, the required amount of acid is injected slowly into this second reactor of the Lödige type using a magnetic proportioner, while stirring with the plow-type blades operating between 200 and 600 rpm. After this time during which the acid is added, the intensifier turbines are switched on between 1500 and 3000 rpm.
[0058] While the metal carboxylate is in the second reactor, manufacture of the metal aminoate is carried out in the first reactor. Water at 90° C. and zinc sulfate or metal derivative depending on the compound are added, stirring until it dissolves. Then, in the case of the aminoate, the amino acid is added and between 0.1% and 0.3% of soda is added as neutralizing agent if required, stirring until chelation is completed. On completion of chelation, the discharge outlet with sluice valve separating the two reactors is opened and the reaction mixture is allowed to descend to the second reactor.
[0059] Once all of the aminoate has been poured onto the carboxylate, the equipment is sealed and the vacuum is switched on, and will be maintained until the final product has been discharged. The vacuum system will draw off, in the form of steam, the water molecules produced in the same reaction with a proportion of the acid (between 1 and 2%), and the water arising from the chelation process. To complete this extraction more immediately, the intensifier turbines are operated at between 1500 and 3000 rpm and will break up any lumps and ensure faster release of moisture from the particles, assisted by the heat of the reaction and the heat of the double jacket with hot oil or preferably steam between 80 and 130° C. Absorbent is added if required. Total process time is between 20 and 70 minutes. The dry product obtained is submitted to an additional grinding operation.
[0060] The order can be changed without any significant effect on product quality.
EXAMPLE 6
Zinc formate-aminoate (glycinate) (50%-50%), on an Industrial Scale
[0061] 800 kg of zinc formate was prepared using the equipment described previously. Firstly the reactor of the Lödige type was charged with 446 kg of ZnO and 554 kg of formic acid (85%) was added slowly, stirring with the plow-type blades at 400 rpm. Then the mouth of the equipment was closed, the vacuum was switched on to draw off the water vapor produced and the intensifier turbine was switched on at 2000 rpm to break up the lumps that had formed and promote the removal of water. The reaction temperature is 110-120° C. After stirring for 5 minutes, the product is obtained as a moist white solid.
[0062] While the carboxylate is being produced in the reactor of the Lödige type, 131.3 kg of water and 686 kg of metal salt (zinc sulfate heptahydrate) are added to the first stirred tank reactor, then 180.1 kg of amino acid and 2.6 of soda are added, maintaining the jacket of the vessel at 90° C. and stirring continuously.
[0063] After 20 minutes, 70 kg of absorbent is added and the aminoate is poured onto the carboxylate, followed by the drying process. Finally grinding is carried out to obtain the granulometry required for marketing. The final product obtained contains 30% Zn, of which 30% is from the aminoate and 70% from the carboxylate.
EXAMPLE 7
Zinc formate-aminoate (methioninate) (50%-50%), on an Industrial Scale
[0064] 800 kg of zinc formate was prepared using the equipment described previously. Firstly, the first reactor was charged with 446.0 kg of ZnO and 554.0 kg of formic acid (85%), stirring with the double-saw flat-disk agitator at 2000 rpm for 30 seconds. After this time, the discharge outlet with sluice valve was opened, allowing the product to descend to the second reactor, where it was stirred for 2 minutes with the plow-type blades at 400 rpm and the intensifier turbines at 2000 rpm. Then the discharge outlet was closed, the vacuum was switched on to draw off the water vapor produced and the intensifier turbine was started up at 2000 rpm to break up the lumps that had formed and promote removal of the water. The reaction temperature is 110-120° C. After stirring for 5 minutes, the product is obtained as a moist white solid.
[0065] After transferring the carboxylate from the stirred tank reactor to the second reactor of the Lödige type, and in parallel, 232.1 kg of water and 510.4 kg of metal salt (zinc sulfate heptahydrate) are added to the first reactor, then 255.3 kg of amino acid and 2.3 of soda are added, maintaining the jacket of the vessel at 90° C. and stirring continuously.
[0066] After 20 minutes, 70 kg of absorbent is added and the aminoate is poured onto the carboxylate, and the drying process is carried out. Finally grinding is carried out to obtain the granulometry required for marketing. The final product obtained contains 28% Zn, of which 25% is from the aminoate and 75% from the carboxylate.
EXAMPLE 8
Copper formate-aminoate (methioninate) (50%-50%), on an Industrial Scale
[0067] 800 kg of copper formate was prepared using the equipment described previously. Firstly, the first reactor was charged with 486.0 kg of Cu(OH) 2 and 524.0 kg of formic acid (85%), stirring with the double-saw flat-disk agitator at 2000 rpm for 30 s. After this time the discharge outlet with sluice valve was opened, allowing the product to descend to the second reactor, where it was stirred for 2 minutes with the plow-type blades at 400 rpm and the intensifier turbines at 2000 rpm. Next, the discharge outlet was closed, the vacuum was switched on to draw off the water vapor produced and the intensifier turbine was switched on at 2000 rpm to break up the lumps that had formed and promote removal of the water. The reaction temperature is 110-120° C. After stirring for 5 minutes, the product is obtained as a moist blue solid.
[0068] After transferring the carboxylate from the stirred tank reactor to the second reactor of the Lödige type, and in parallel, 131.3 kg of water and 542.0 kg of metal salt (copper sulfate pentahydrate) are added to the first reactor, then 324.1 kg of amino acid and 2.6 of soda are added, maintaining the jacket of the vessel at 90° C. and stirring continuously.
[0069] After 20 minutes, 70 kg of absorbent is added and the aminoate is poured onto the carboxylate, and the drying process is carried out. Finally grinding is carried out to obtain the granulometry required for marketing. The final product obtained contains 27% Cu, of which 25% is from the aminoate and 75% from the carboxylate.
[0000] Production of Carboxylate-methioninate Hydroxy Analogs
[0070] For the case of carboxylate-methioninate hydroxy analog, the procedure is described below:
[0071] The basic metal compound is added to the second reactor of the Lödige type by means of a proportioner with load cells, and a quantity of product that has already reacted. From the stainless steel storage tanks (INOX AISI-304L), where the mixture of carboxylic acid and methioninate hydroxy analog is received, the required amount of acid mixture is injected slowly into this second reactor of the Lödige type using a magnetic proportioner, stirring with the plow-type blades operating at between 200 and 600 rpm. After this time for addition of the acid, the intensifier turbines are switched on at between 1500 and 3000 rpm to break up any lumps and ensure faster release of moisture from the particles, assisted by the heat of the reaction and the heat of the double jacket with hot oil or preferably steam between 80 and 130° C. Total process time is between 20 and 70 minutes.
EXAMPLE 9
Zinc formate-methioninate hydroxy analog (HMA) (70%-30%), on an Industrial Scale
[0072] The industrial-scale example of zinc formate-methioninate hydroxy analog is described below. 296.70 kg of ZnO is added to the second reactor of the Lödige type by means of a proportioner with load cells or some other metering system. From the stainless steel storage tanks (INOX AISI-304L), 166.20 kg of formic acid (85%) and 564.10 kg of HMA (88.80%) are injected into the first reactor of the STR type, the acids are mixed together, at room temperature and at atmospheric pressure, until uniform dissolution is achieved. At the end of stirring, the discharge outlet with diaphragm-type valve separating the two reactors is opened and allowed to transfer slowly onto the zinc oxide. While the mixture of acids is being added, stirring with the plow-type blades continues at 400 rpm and the vacuum that will draw off, throughout the manufacturing operation, the water vapor that is produced in the same reaction and a proportion of the mixture of acids (between 1 and 2%). Furthermore, to complete this extraction more immediately, the intensifier turbines are operated at between 1500 and 3000 rpm to break up any lumps and ensure faster release of moisture from the particles, assisted by the heat of the reaction 60-70° C. and the heat of the double jacket, a temperature of 90° C. is maintained, which also promotes evaporation of the water. Total process time is between 20 and 70 minutes.
[0073] Finally, grinding is carried out to obtain the granulometry required for marketing. The final product obtained contains 27% of Zn, of which 50% is from the methioninate hydroxy analog and 50% from the carboxylate.
[0000] Comparative Tests of Efficacy
[0000] Tests of Efficacy of Metal Carboxylates
EXAMPLE 10
Test of Efficacy in Broilers: (chicken 7 Weeks Old, Ready for Consumption)
[0000] Objectives: To determine the effectiveness of copper formate and copper butyrate on the production parameters of broilers.
[0000] Materials and Methods
[0000] Animals and Housing:
[0074] 1600 one-day old broilers of the Ross strain were used (without differentiation of sexes), housed in 40 pens of 4 m 2 .
[0000] Experimental Treatments
[0075] Five experimental treatments were used, comprising the same basic diet supplemented with different sources of copper:
T-0: Base diet +0.0056% copper sulfate (20 ppm of copper) T-1: Base diet +0.0055% copper formate (20 ppm of copper) T-2: Base diet +0.0073% copper butyrate (20 ppm of copper) T-3: Base diet +0.0417% copper sulfate (150 ppm of copper)
[0080] The dose of copper added was calculated taking into account the natural copper content of the ingredients of the feed (about 15 ppm) and the maximum permitted dose in the finished feed (35 ppm of copper) in the case of treatments T-0 to T-2, and the dose with promoter effect (170 ppm of copper) in the case of treatment T-3. By adding 20 ppm of copper in the form of copper formate or butyrate to the feed, we aimed to obtain the same promoter effect as with the dose of 170 ppm of copper added as copper sulfate, but complying with the established legal levels.
[0081] The composition of the diets and their analysis are presented in Tables 1, 2 and 3.
[0082] The experimental model was a design of random blocks, with 8 replications per treatment. Each replication comprised a batch of 40 animals.
[0000] Controls
[0083] Control of production parameters was effected at 21 and 42 days of age, recording the live weight and the consumption of feed per batch.
[0084] On day 42 of the experiment, 2 animals were selected at random from each batch and were placed in cages in pairs according to their origin with respect to batch and previous treatment. During the next 4 days, an investigation of the bioavailability of the copper was carried out. After fasting for 20 hours, the live weight per cage was recorded and the experimental feeds were supplied for 2 days, recording the consumption of feed. After fasting again for 20 hours, the birds were weighed again per cage. All of the excrement was collected per cage for the entire period when weight records were kept. After weighing and homogenizing all of the excrement, a representative sample was taken from each cage for performing the analysis for copper. The copper excreted was calculated as a percentage of the copper ingested.
[0000] Statistical Analysis:
[0085] An analysis of variance was carried out using the GLM (generalized linear model) procedure of the SAS® statistical software (SAS Institute, 1996) applying the random block model.
[0000] Results
[0086] The results for the production parameters are shown in Table 4. Treatments T-1 to T-3 produced better production parameters relative to the control, in all the periods. The consumption of feed was slightly less for the birds fed with copper butyrate, which produced an improvement in the conversion index, but this was not significant. Thus, copper sulfate administered at a dose of 150 ppm produced growth-promoting effects relative to the control, as is already known. The administration of lower doses of copper in the form of copper formate and butyrate (20 ppm) produced the same promoter effect as the 150 ppm dose in the form of copper sulfate.
[0087] The results for copper bioavailability are shown in Table 5. The highest bioavailability was observed in treatments with copper formate and butyrate, demonstrating greater absorption of this mineral form in the intestine.
[0088] The supplementation of diets for broilers with copper in the form of butyric and formic salts at the doses laid down by the legislation produces an improvement in the production parameters, which can be regarded as a growth-promoter effect. Moreover, said sources of copper display greater bioavailability, so there is less emission of residues to the environment.
TABLE 1 Composition of the experimental diets: 0-21 d 21-42 d Ingredients Wheat 38.000 48.000 Maize 22.579 16.050 Soya, 47% 28.703 26.560 Soya, extruded 2.877 3.831 Lard 2.780 2.540 DL-methionine 0.259 0.238 L-lysine HCl 0.177 0.104 Calcium carbonate 1.269 0.697 Dicalcium phosphate 1.486 1.259 Salt 0.446 0.312 Minerals and vitamins 1 0.400 0.400 Choline chloride, 50% 0.023 0.012 Potato protein 1.000 Analysis Gross protein, % 21.02 20.7 Gross fat, % 9.21 1.14 Gross fiber, % 4.85 1.02 Moisture, % 8.61 0.90 1 Copper-free vitamin-mineral supplement.
[0089]
TABLE 2
Addition of sources of copper (%)
Ingredients
T-0
T-1
T-2
T-3
Copper sulfate
0.0056
0.0417
Copper formate
0.0055
Copper butyrate
0.0073
[0090]
TABLE 3
Analysis of copper content (ppm)
Treatment
0-21 d
21-42 d
T-0
33.25
35.20
T-1
32.60
31.9
T-2
34.56
34.8
T-3
172.5
167.2
[0091]
TABLE 4
Production parameters
0-21 days
21-42 days
0-42 days
LW
MDG
MDC
LW
MDG
MDC
MDG
MDC
Treatment
21 d (g)
(g)
(g/d)
IC
42 d (g)
(g)
(g/d)
IC
(g)
(g/d)
IC
T-0
716 a
34.2 a
48.9
1.43 a
2172 a
69.2 a
149.3
2.16 a
50.6 a
98.2
1.94 a
a
T-1
755 b
36.1 b
49.6
1.37 b
2360 b
76.3 b
152.5
2.00 b
55.1 b
99.3
1.80 b
T-2
763 b
36.2 b
48.9
1.35 b
2358 b
75.9 b
147.2
1.94 b
55.1 b
97.2
1.76 b
a
T-3
756 b
35.9 b
49.7
1.38 b
2362 b
76.7 b
154.2
2.01 b
55.2 b
99.5
1.80 b
S.E.
11.4
0.5
0.76
0.014
35.02
1.32
2.52
0.036
1.23
1.27
0.031
Sig.
*
*
N.S
*
*
*
N.S
*
*
N.S
*
a , b : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion S.E: Standard error; Sig.: significance
[0092]
TABLE 5
Copper balance from 43 to 46 days of age:
Consumption
Copper
Copper
Bioavail-
Treatment
of feed (g)
ingested (mg)
excreted (mg)
ability %
T-0
206
7.3 a
4.08 a
43.73 a
T-1
222
7.1 a
3.12 a
55.94 b
T-2
210
7.3 a
2.99 a
59.09 b
T-3
206
652.4 b
397.3 b
39.11 3
S.E.
3.6
3.2
2.6
1.01
Sig.
N.S.
*
*
*
a , b Values in the same column with different superscript differ significantly (P < 0.05)
EXAMPLE 11
Test of Efficacy in Piglets
[0000] Objectives:
[0093] To determine the effectiveness of zinc formate and zinc butyrate on the production parameters of recently weaned piglets.
[0000] Materials and Methods
[0000] Animals and Housing:
[0094] 300 piglets were used (cross of Large White and Landrace), 50% males and 50% females, weaned at 21 days of age and housed in 30 pens with 10 animals in each (5 males and 5 females).
[0000] Experimental Treatments
[0095] Five experimental treatments were used, comprising the same basic diet, to which different sources of zinc are added:
T-0: Base diet+0.0275% zinc oxide (220 ppm of zinc) T-1: Base diet+0.0560% zinc formate (220 ppm of zinc) T-2: Base diet+0.0797% zinc butyrate (220 ppm of zinc) T-3: Base diet+0.2463% zinc oxide (1970 ppm of zinc)
[0100] The zinc dose was calculated taking into account the zinc content of the ingredients of the feed and the maximum permitted dose (250 ppm of zinc in the finished feed) in the case of treatments T-0 to T-2, and the dose with promoter effect (2000 ppm) in the case of treatment T-3. By adding 220 ppm of zinc in the form of zinc formate or butyrate to the feed, we hoped to obtain the same promoter effect as with the dose of 1970 ppm of copper added as zinc oxide, but complying with the established legal levels.
[0101] The composition of the diets and their analysis are presented in Tables 6, 7 and 8. The experimental period was 21 days.
[0102] The experimental model was a design of random blocks, with 6 replications per treatment. Each replication comprised a batch of 10 animals.
[0000] Controls
[0103] Control of production parameters was effected at the end of the experiment, recording the live weight, the daily growth and the consumption of feed.
[0104] At the end of the experiment, one male and one female were selected at random from each batch to take a specimen of liver tissue and determine the zinc content.
[0000] Statistical Analysis:
[0105] An analysis of variance was carried out using the GLM (generalized linear model) procedure of the SAS® statistical software (SAS Institute, 1996) applying the random block model.
[0000] Results
[0106] The results for the production parameters are shown in Table 9. Treatments T-1 to T-3 produced better production parameters relative to the control, in all the periods. The consumption of feed was slightly less for the birds fed with zinc butyrate and formate, which produced an improvement in the conversion index, but this was not significant. Thus, zinc oxide administered at a dose of 1970 ppm produced growth-promoting effects relative to the control, as is already known. The administration of lower doses of zinc in the form of zinc formate and butyrate (220 ppm) produced the same promoter effect as the 1970 ppm dose.
[0107] The results for the liver zinc concentration are shown in Table 10. The highest concentration was observed in treatment with zinc oxide at a dose of 1970 ppm and the lowest in treatment with zinc oxide at a dose of 220 ppm. Determination of the ratio of zinc in the liver to zinc in the diet shows that the highest ratio occurs in animals fed with zinc formate and butyrate, indicating greater bioavailability of zinc when it forms formic and butyric salts.
[0108] When the diet of piglets is supplemented with zinc in the form of butyric and formic salts at the doses laid down by the legislation, there is an improvement in the production parameters, which can be regarded as a growth-promoter effect. Moreover, these sources of zinc display greater bioavailability, so that there is less emission of residues to the environment.
TABLE 6 Composition of the experimental diets: 21-42 d Ingredients Maize 30.0 Wheat 5.0 Barley 15.0 Soya (full fat) 14.0 Fish meal 9.9 Soya flour (47%) 2.0 Soya oil 1.9 Delactosed whey 3.1 Sweet whey 17.0 L-lysine (78%) 0.2 L-threonine (99%) 0.14 Methionine-OH 0.18 Calcium carbonate 0.34 Dicalcium phosphate 0.85 Vitamin-mineral complex 1 0.3 Analysis Gross protein, % 21.02 Gross fat, % 7.20 Gross fiber, % 2.52 Moisture, % 8.40 1 Zinc-free vitamin-mineral supplement.
[0109]
TABLE 7
Addition of sources of zinc to the feed (%)
Ingredients
T-0
T-1
T-2
T-3
Copper sulfate
0.0275
0.2463
Copper formate
0.0560
Copper butyrate
0.0797
[0110]
TABLE 8
Analysis of zinc content in the diets (ppm)
Treatment
Zinc
T-0
241.2
T-1
232.2
T-2
252.3
T-3
1963.2
[0111]
TABLE 9
Production parameters from 21 to 42 days:
21-28 days
21-42 days
LW
MDG
MDC
LW
MDG
MDC
Treatment
28 d (kg)
(g)
(g/d)
IC
42 d (kg)
(g)
(g/d)
IC
T-0
8.41 A
244.5 A
321.7
1.32 a
13.11 a
475.3 a
795.3
1.67 a
T-1
8.76 ab
268.6 B
312.3
1.16 b
14.30 b
512.6 b
752.3
1.47 b
T-2
8.99 B
262.9 ab
286.3
1.09 b
14.15 b
509.6 b
741.3
1.45 b
T-3
9.01 B
273.5 B
312.2
1.14 b
13.97 ab
511.3 b
763.2
1.49 b
S.E.
0.12
6.3
7.5
0.014
0.27
8.26
11.62
0.011
Sig.
*
*
N.S
*
*
*
N.S
*
a , b : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion S.E: Standard error; Sig.: significance
[0112] TABLE 10 Zinc concentration in the liver (μg/g): Ratio Treatment Liver zinc Zn in liver/Zn in diet T-0 47.63 a 19.5 ab T-1 59.21 a 25.5 c T-2 56.3 a 22.3 bc T-3 298.5 b 15.2 a S.E. 2.6 0.47 Sig. * * a , b , c Values in the same column with different superscript differ significantly (P < 0.05)
Comparative Tests of Efficacy of Aminoate-Carboxylates
EXAMPLE 12
Test in Broilers
[0113] Objectives: To compare the effectiveness of the zinc aminoate (methioninate) products with zinc formate and with the product obtained by combining both compounds which will be called zinc methioninate-formate complex hereinafter, on the production parameters for broilers.
[0000] Materials and Methods
[0000] Animals and housing:
[0114] 192 one-day old broilers of the Ross strain were used (without differentiation of sexes), housed in 16 cages of 4 m 2 .
[0000] Experimental Treatments
[0115] Four experimental treatments were used, comprising the same basic diet supplemented with different sources of zinc:
T-0: Base diet+50 ppm of zinc in the form of zinc sulfate T-1: Base diet+50 ppm of zinc in the form of zinc formate T-2: Base diet+50 ppm of zinc in the form of zinc methioninate T-3: Base diet+50 ppm of zinc in the form of zinc methioninate-formate complex
[0120] The dose of zinc was calculated taking into account the zinc content of the ingredients and the zinc requirements in the case of treatments T-0 to T-3. The composition of the diets and their analysis are presented in Tables 1 and 2.
[0000] Controls
[0121] Control of production parameters was effected at 21 and 42 days of age, recording the live weight and the consumption of feed per batch.
[0122] On day 42 of the experiment, 2 animals were selected at random from each batch and were placed in cages in pairs according to their origin with respect to batch and previous treatment. During the next 4 days, an investigation of zinc bioavailability was carried out. After fasting for 20 hours, the live weight per cage was recorded and the experimental feeds were supplied for 2 days, recording the consumption of feed. After fasting again for 20 hours, the birds were weighed again per cage. All of the excrement was collected per cage for the entire period in which weight records were kept. After weighing and homogenizing all of the excrement, a representative sample was taken from each cage for performing the analysis for zinc. The zinc excreted was calculated as a percentage of the zinc ingested.
[0000] Statistical Analysis:
[0123] An analysis of variance was carried out using the GLM procedure of the SAS statistical software.
[0000] Results
[0124] The results for the production parameters are shown in Table 3. Treatments T-1 to T-3 produced better production parameters relative to the control T-0, in all the periods. The consumption of feed was slightly less for the birds fed with zinc formate, which produced an improvement in the conversion index, but this was not significant. The administration of zinc in the form of zinc formate and methioninate (50 ppm) produced the same effect, treatment T-3 improved the production parameters significantly relative to treatments T-0, T-1 and T-2.
[0125] The results for zinc bioavailability are shown in Table 5. The highest bioavailability was observed in the treatments with zinc formate, zinc methioninate and the methioninate-formate complex, demonstrating greater absorption of this mineral form in the intestine.
[0000] Conclusions
[0126] The supplementation of diets for broilers with zinc in the form of salts of amino acid and formic acid at the doses laid down by the legislation produce an improvement in the production parameters. This improvement was more significant when the product administered was in the form of amino acid-zinc formate complex, owing to a synergistic effect of the two products combined. Moreover, said sources of zinc display greater bioavailability, so there is less emission of residues to the environment.
TABLE 11 Composition of the experimental diets %: 0-21 d 21-42 d Ingredients Wheat 38.00 48.00 Maize 22.58 16.05 Soya, 47% 28.70 26.56 Soya, extruded 2.87 3.83 Lard 2.78 2.54 DL-methionine 0.259 0.238 L-lysine HCl 0.177 0.104 Calcium carbonate 1.269 0.697 Dicalcium phosphate 1.486 1.25 Salt 0.446 0.312 Minerals and vitamins 1 0.400 0.400 Choline chloride, 50% 0.023 0.012 Potato protein 1.00 Analysis Gross protein, % 21.02 20.7 Gross fat, % 9.21 1.14 Gross fiber, % 4.85 1.02 Moisture, % 8.61 0.90 1 Zinc-free vitamin-mineral supplement.
[0127]
TABLE 12
Analysis of zinc content (ppm)
Treatment
0-21 d
21-42 d
T-0
60.32
58.05
T-1
61.35
59.75
T-2
58.29
62.10
T-3
62.35
60.25
T-0
60.32
58.05
T-1
61.35
59.75
T-2
58.29
62.10
T-3
62.35
60.25
[0128]
TABLE 13
Production parameters
0-21 days
21-42 days
0-42 days
LW
MDG
MDC
LW
MDG
MDC
MDG
MDC
Treatment
21 d (g)
(g)
(g/d)
IC
42 d (g)
(g)
(g/d)
IC
(g)
(g/d)
IC
T-0
705 a
33.6 a
47.3
1.40 a
2250 a
73.6 a
156.3
2.12 a
53.5 a
101.7
1.90 a
a
T-1
740 b
35.2 b
48.3
1.37 b
2310 b
74.8 b
152.5
2.03 b
55.0 b
100.4
1.82 b
T-2
750 b
35.7 b
48.1
1.35 b
2340 b
75.7 b
155.2
2.05 b
55.7 b
101.7
1.82 b
T-3
790 c
37.6 c
50.5
1.34 c
2430 c
78.1 c
150.2
1.92 c
57.8 c
100.4
1.73 c
Sig.
*
*
N.S
*
*
*
N.S
*
*
N.S
*
a , b , c : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion Sig.: significance
[0129]
TABLE 14
Zinc balance from 43 to 46 days of age:
Zinc
Zinc
Consumption
ingested
excreted
Bioavailability
Treatment
of feed (g)
(mg)
(mg)
%
T-0
206
12.4 a
8.34 a
33.0 a
T-1
222
13.3 a
7.20 b
45.8 b
T-2
210
12.6 a
7.35 b
42.6 b
T-3
206
12.4 a
6.01 c
51.5 c
Sig.
N.S.
N.S.
*
*
a , b , c Values in the same column with different superscript differ significantly (P < 0.05)
EXAMPLE 13
Test in Broilers
[0000] Objectives:
[0130] To compare the effectiveness of the copper aminoate (methioninate) products with copper formate and with the product obtained by combining both compounds which will be called copper methioninate-formate complex hereinafter, on the production parameters for broilers.
[0000] Material and Methods
[0000] Animals and Housing:
[0131] 500 one-day old broilers of the Ross strain were used (without differentiation of sexes) , housed in 20 pens of 4 m 2 .
[0000] Experimental Treatments
[0132] Four experimental treatments were used, comprising the same basic diet supplemented with different sources of copper:
T-0: Base diet+25 ppm of copper in the form of copper sulfate T-1: Base diet+25 ppm of copper in the form of copper formate T-2: Base diet+25 ppm of copper in the form of copper methioninate T-3: Base diet+25 ppm of copper in the form of copper methioninate-formate complex
[0137] The dose of copper was calculated taking into account the copper content of the ingredients and the copper requirements in the case of treatments T-0 to T-3. The composition of the diets and their analysis are presented in Tables 1 and 2.
[0000] Controls
[0138] Control of production parameters was effected at 21 and 42 days of age, recording the live weight and the consumption of feed per batch.
[0139] On day 42 of the experiment, 2 animals were selected at random from each batch and were placed in cages in pairs according to their origin with respect to batch and previous treatment. During the next 4 days, an investigation of copper bioavailability was carried out. After fasting for 20 hours, the live weight per cage was recorded and the experimental feeds were supplied for 2 days, recording the consumption of feed. After fasting again for 20 hours, the birds were weighed again per cage. All of the excrement was collected per cage for the entire period in which weight records were kept. After weighing and homogenizing all of the excrement, a representative sample was taken from each cage for performing the analysis for copper. The copper excreted was calculated as a percentage of the copper ingested.
[0000] Statistical Analysis:
[0140] An analysis of variance was carried out using the GLM procedure of the SAS statistical software.
[0000] Results
[0141] The results for the production parameters are shown in Table 3. Treatments T-1 to T-3 produced better production parameters relative to the control T-0, in all the periods. The consumption of feed was slightly less for the birds fed with copper formate, which produced an improvement in the conversion index, but this was not significant. The administration of copper in the form of copper formate and methioninate (25 ppm) produced the same effect, treatment T-3 improved the production parameters significantly relative to treatments T-0, T-1 and T-2.
[0142] The results for copper bioavailability are shown in Table 5. The highest bioavailability was observed in the treatments with copper formate, copper methioninate and the methioninate-formate complex, demonstrating greater absorption of this mineral form in the intestine.
[0000] Conclusions
[0143] The supplementation of diets for broilers with copper in the form of salts of methionine and formic acid at the doses laid down by the legislation produce an improvement in the production parameters. This improvement was more significant when the product administered was in the form of copper methioninate-formate complex, owing to a synergistic effect of the two products combined. Moreover, said sources of copper display greater bioavailability, so there is less emission of residues to the environment.
TABLE 15 Composition of the experimental diets %: 0-21 d 21-42 d Ingredients Wheat 38.00 48.00 Maize 22.58 16.05 Soya, 47% 28.70 26.56 Soya, extruded 2.87 3.83 Lard 2.78 2.54 DL-methionine 0.259 0.238 L-lysine HCl 0.177 0.104 Calcium carbonate 1.269 0.697 Dicalcium phosphate 1.486 1.25 Salt 0.446 0.312 Minerals and vitamins 1 0.400 0.400 Choline chloride, 50% 0.023 0.012 Potato protein 1.00 Analysis Gross protein, % 21.02 20.7 Gross fat, % 9.21 1.14 Gross fiber, % 4.85 1.02 Moisture, % 8.61 0.90 1 Copper-free vitamin-mineral supplement.
[0144]
TABLE 16
Analysis of copper content (ppm)
Treatment
0-21 d
21-42 d
T-0
31.5
32.8
T-1
33.5
32.5
T-2
32.7
33.0
T-3
33.8
35.5
[0145]
TABLE 17
Production parameters
0-21 days
21-42 days
0-42 days
LW
MDG
MDC
LW
MDG
MDC
MDG
MDC
Treatment
21 d (g)
(g)
(g/d)
IC
42 d (g)
(g)
(g/d)
IC
(g)
(g/d)
IC
T-0
695 a
31.6 a
45.3
1.43 a
2200 a
71.6 a
160.1
2.23 a
51.6 a
102.7
1.99 a
T-1
730 b
34.2 b
47.3
1.38 b
2350 b
77.1 c
158.3
2.05 b
55.2 b
103.0
1.87 b
T-2
750 b
34.7 b
47.1
1.36 b
2300 b
73.8 b
154.0
2.08 b
54.0 b
100.5
1.86 b
T-3
775 c
39.6 c
53.5
1.35 b
2450 c
79.7 c
152.5
1.92 c
57.6 c
103.0
1.78 c
Sig.
*
*
N.S
*
*
*
N.S
*
*
N.S
*
a , b , c : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion Sig.: significance
[0146]
TABLE 18
Copper balance from 43 to 46 days of age:
Consumption
Copper
Copper
Bioavail-
Treatment
of feed (g)
ingested (mg)
excreted (mg)
ability %
T-0
206
67.98 a
20.4 a
30.0 a
T-1
222
73.26 a
36.9 b
50.5 b
T-2
210
69.3 a
29.5 b
42.6 b
T-3
206
68.0 a
37.7 c
55.5 c
Sig.
N.S.
N.S.
*
*
a , b , c Values in the same column with different superscript differ significantly (P < 0.05)
EXAMPLE 14
Test of Efficacy in Piglets
[0000] Objectives:
[0147] To compare the effectiveness of the zinc aminoate (glycinate) and zinc formate products and the product obtained by combining both compounds which will be called zinc complex hereinafter, on the production parameters for recently weaned piglets.
[0000] Material and Methods
[0000] Animals and Housing:
[0148] 48 piglets were used (Large White * Large White x Landrace), 50% males and 50% females, weaned at 21 days of age and housed in 8 pens with 6 animals in each (3 males and 3 females).
[0000] Experimental Treatments
[0149] Five experimental treatments were used, comprising the same basic diet, to which different sources of zinc were added:
T-0: Base diet+130 ppm of zinc in the form of zinc oxide T-1: Base diet+130 ppm of zinc in the form of zinc formate T-2: Base diet+130 ppm of zinc in the form of zinc glycinate T-3: Base diet+130 ppm of zinc in the form of zinc glycinate-formate complex
[0154] The zinc dose was calculated taking into account the zinc content of the ingredients and the maximum permitted dose (150 ppm) in all the treatments.
[0155] The composition of the diets and their analysis are presented in Tables 1 and 2.
[0156] The experimental period was 29 days.
[0000] Controls
[0157] Control of production parameters was effected at the end of the experiment, recording the live weight, the daily growth and the consumption of feed.
[0158] At the end of the experiment, one male and one female were selected at random from each batch to take a specimen of liver tissue and determine the zinc content.
[0000] Statistical Analysis:
[0159] An analysis of variance was carried out using the GLM procedure of the SAS statistical software.
[0000] Results
[0160] The results for the production parameters are shown in Table 3. Treatments T-1 to T-3 produced better production parameters relative to the control, in all the periods. The consumption of feed was slightly less for the piglets fed with the organic sources of zinc, which produced an improvement in the conversion index.
[0000] Conclusions
[0161] When the diet of piglets is supplemented with zinc in the form of salts of formic and amino acid at the doses laid down by the legislation, there is an improvement in the production parameters, which can be regarded as a growth-promoter effect. The improvements were greater when the zinc was administered in the form of zinc glycinate-formate complex. Moreover, these sources of zinc display greater bioavailability, so that there is less emission of residues to the environment.
TABLE 19 Composition of the experimental diets: Ingredients Maize 30.0 Wheat 5.0 Barley 15.0 Soya (full fat) 14.0 Fish meal 9.9 Soya flour (47%) 2.0 Soya oil 1.9 Delactosed whey 3.1 Sweet whey 17.0 L-lysine (78%) 0.2 L-threonine (99%) 0.14 Methionine-OH 0.18 Calcium carbonate 0.34 Dicalcium phosphate 0.85 Vitamin-mineral complex 1 0.3 Analysis Gross protein, % 21.02 Gross fat, % 7.20 Gross fiber, % 2.52 Moisture, % 8.40 1 Zinc-free vitamin-mineral supplement.
[0162]
TABLE 20
Analysis of zinc content in the diets (ppm)
Treatment
Zinc
T-0
153.4
T-1
133.5
T-2
155.4
T-3
145.3
[0163]
TABLE 21
Production parameters from 21 to 50 days:
21-50 days
GLW
Treatment
21-50 d (kg)
MDG (g)
MDC (g/d)
IC
T-0
11.40 a
393.1 a
795.3
2.02 a
T-1
12.50 b
431.0 b
752.3
1.75 b
T-2
12.75 b
439.6 b
741.3
1.68 b
T-3
13.70 c
472.4 c
763.2
1.62 c
Sig.
*
*
N.S
*
a , b , c : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion; GLW: gain in live weight
S.E: Standard error; Sig.: significance
EXAMPLE 15
Test of Efficacy in Piglets
[0000] Objectives:
[0164] To compare the effectiveness of the copper glycinate (glycinate) and copper formate products and the product obtained by combining both compounds which will be called copper complex hereinafter, on the production parameters for recently weaned piglets.
[0000] Material and Methods
[0000] Animals and Housing:
[0165] 48 piglets were used (Large White * Large White x Landrace), 50% males and 50% females, weaned at 21 days of age and housed in 8 pens with 6 animals in each (3 males and 3 females).
[0000] Experimental Treatments
[0166] Five experimental treatments were used, comprising the same basic diet, to which different sources of copper were added:
T-0: Base diet+125 ppm of copper in the form of copper sulfate T-1: Base diet+125 ppm of copper in the form of copper formate T-2: Base diet+125 ppm of copper in the form of copper glycinate T-3: Base diet+125 ppm of copper in the form of copper glycinate-formate complex
[0171] The copper dose was calculated taking into account the copper content of the ingredients and the maximum permitted dose (175 ppm) in all the treatments.
[0172] The composition of the diets and their analysis are presented in Tables 1 and 2.
[0173] The experimental period was 21 days.
[0000] Controls
[0174] Control of production parameters was effected at the end of the experiment, recording the live weight, the daily growth and the consumption of feed.
[0175] At the end of the experiment, one male and one female were selected at random from each batch to take a specimen of liver tissue and determine the copper content.
[0000] Statistical Analysis:
[0176] An analysis of variance was carried out using the GLM procedure of the SAS statistical software.
[0000] Results
[0177] The results for the production parameters are shown in Table 3. Treatments T-1 to T-3 produced better production parameters relative to the control, in all the periods. The consumption of feed was slightly less for the piglets fed with the organic sources of copper, which produced an improvement in the conversion index.
[0000] Conclusions
[0178] When the diet of piglets is supplemented with copper in the form of salts of formic and amino acid at the doses laid down by the legislation, there is an improvement in the production parameters, which can be regarded as a growth-promoter effect. The improvements were greater when the copper was administered in the form of copper glycinate-formate complex. Moreover, these sources of copper display greater bioavailability, so that there is less emission of residues to the environment.
TABLE 22 Composition of the experimental diets: Ingredients Maize 30.0 Wheat 5.0 Barley 15.0 Soya (full fat) 14.0 Fish meal 9.9 Soya flour (47%) 2.0 Soya oil 1.9 Delactosed whey 3.1 Sweet whey 17.0 L-lysine (78%) 0.2 L-threonine (99%) 0.14 Methionine-OH 0.18 Calcium carbonate 0.34 Dicalcium phosphate 0.85 Vitamin-mineral complex 1 0.3 Analysis Gross protein, % 21.02 Gross fat, % 7.20 Gross fiber, % 2.52 Moisture, % 8.40 1 Copper-free vitamin-mineral supplement.
[0179]
TABLE 23
Analysis of copper content in the diets (ppm)
Treatment
Copper
T-0
140.5
T-1
143.5
T-2
138.5
T-3
140.0
[0180]
TABLE 24
Production parameters from 21 to 42 days:
21-42 days
GLW
Treatment
21-42 d (kg)
MDG (g)
MDC (g/d)
IC
T-0
6.5 a
309.5 a
650.5
2.10 a
T-1
7.5 b
360.5 b
665.0
1.85 b
T-2
7.25 b
345.0 b
660.5
1.91 b
T-3
7.75 c
370.0 c
650.5
1.75 c
Sig.
*
*
N.S
*
a , b , c : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion; GLW: gain in live weight
S.E: Standard error; Sig.: significance
EXAMPLE 16
Test in Broilers
[0000] Objectives:
[0181] To compare the effectiveness of the zinc carboxylate (zinc formate) products and the product obtained by combining the zinc salt of the hydroxy analog of methionine and zinc carboxylate.
[0000] Material and Methods
[0000] Animals and Housing:
[0182] 160 one-day old broilers of the Ross strain were used (without differentiation of sexes), housed in cages in groups of 10 animals.
[0000] Experimental Treatments
[0183] Two experimental treatments were used, comprising the same basic diet to which different sources of zinc were added:
T-1: Base diet+150 ppm of zinc in the form of zinc formate T-2: Base diet+150 ppm of zinc in the form of methionine hydroxy analog-zinc formate complex
Controls
[0186] Control of production parameters was effected at 21 days of age, recording the live weight and the consumption of feed per batch.
[0000] Statistical Analysis:
[0187] An analysis of variance was carried out using the GLM procedure of the SAS statistical software.
[0000] Results
[0188] The results for the production parameters are shown in Table 3. Treatment T-2 produced better production parameters relative to the control T-1, in this period. The consumption of feed was slightly less for the birds fed with zinc formate-methioninate hydroxy analog complex, which produced an improvement in the conversion index.
[0000] Conclusions
[0189] The supplementation of diets for broilers with zinc in the form of formate-methionine hydroxy analog complexes at the doses laid down by the legislation produce an improvement in the production parameters.
TABLE 25 Composition of the experimental diets %: 0-21 d Ingredients Wheat 38.00 Maize 22.58 Soya, 47% 28.70 Soya, extruded 2.87 Lard 2.78 DL-methionine 0.259 L-lysine HCl 0.177 Calcium carbonate 1.269 Dicalcium phosphate 1.486 Salt 0.446 Minerals and vitamins 1 0.400 Choline chloride, 50% 0.023 Potato protein 1.00 Analysis Gross protein, % 21.02 Gross fat, % 9.21 Gross fiber, % 4.85 Moisture, % 8.61 1 Zinc-free vitamin-mineral supplement.
[0190]
TABLE 26
Analysis of zinc content (ppm)
Treatment
0-21 d
T-1
160
T-2
165
[0191]
TABLE 27
Production parameters
0-21 days
Treatment
LW 21 d (g)
MDG (g)
MDC (g/d)
IC
T-1
790 b
37.6 b
47.5
1.26 b
T-2
820 a
39.0 a
47.0
1.20 a
Sig.
*
*
N.S
*
a , b : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion
Sig.: significance
EXAMPLE 17
Test of Efficacy in Piglets
[0000] Objectives:
[0192] To compare the effectiveness of the zinc carboxylate (zinc formate) products and the product obtained by combining the zinc salt of the hydroxy analog of methionine and the zinc carboxylate in recently weaned piglets.
[0000] Material and Methods
[0000] Animals and Housing:
[0193] 24 piglets were used (Large White * Large White x Landrace), 50% males and 50% females, weaned at 21 days of age and housed in 4 pens with 6 animals in each (3 males and 3 females).
[0000] Experimental Treatments
[0194] Two experimental treatments were used, comprising the same basic diet, to which different sources of zinc were added:
T-1: Base diet+150 ppm of zinc in the form of zinc formate T-2: Base diet+150 ppm of zinc in the form of methionine hydroxy analog-zinc formate complex
[0197] The zinc dose was calculated taking into account the zinc content of the ingredients and the maximum permitted dose (150 ppm) in all the treatments.
[0198] The composition of the diets and their analysis are presented in Tables 1 and 2.
[0199] The experimental period was 20 days.
[0000] Controls
[0200] Control of production parameters was effected at the end of the experiment, recording the live weight, the daily growth and the consumption of feed.
[0000] Statistical Analysis:
[0201] An analysis of variance was carried out using the GLM procedure of the SAS statistical software.
[0000] Results
[0202] The results for the production parameters are shown in Table 3. Treatment T-2 produced better results with respect to conversion index and growth than treatment T-1. These data corroborate the previous experiments conducted on fattening chicken.
[0000] Conclusions
[0203] When the diet of piglets is supplemented with zinc in the form of salts of methionine hydroxy analog-zinc formate complexes at the doses laid down by the legislation, there is an improvement in the production parameters, which can be regarded as a growth-promoter effect.
TABLE 28 Composition of the experimental diets: Ingredients Maize 28.0 Barley 17.0 Soya (full fat) 15.0 Fish meal 10.0 Soya flour (47%) 2.0 Soya oil 2.0 Delactosed whey 2.0 Sweet whey 19.0 L-lysine (78%) 0.2 L-threonine (99%) 0.14 Methionine-OH 0.15 Calcium carbonate 0.35 Dicalcium phosphate 0.85 Vitamin-mineral complex 1 0.3 Analysis Gross protein, % 21.0 Gross fat, % 7.5 Gross fiber, % 3.0 Moisture, % 7.5 1 Zinc-free vitamin-mineral supplement.
[0204]
TABLE 29
Analysis of zinc content in the diets (ppm)
Treatment
Zinc
T-1
165.4
T-2
168.5
[0205]
TABLE 30
Production parameters from 21 to 41 days:
21-41 days
GLW
Treatment
21-41 d (kg)
MDG (g)
MDC (g/d)
IC
T-1
8.00 b
400.0 b
655.0
1.63 b
T-2
9.00 b
450.0 a
660.0
1.47 a
Sig.
N.S.
*
N.S
*
a , b , c : Values in the same column with different superscript differ significantly (P < 0.05)
LW: Live weight; MDG: mean daily gain; MDC: mean daily consumption; IC: index of conversion; GLW: gain in live weight
S.E: Standard error; Sig.: significance
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A method of production of metal carboxylates and of their metal carboxylate-aminoate or metal carboxylate-methioninate hydroxy analog derivatives, and their use as growth promoters in animal nutrition. It comprises mixing stoichiometric quantities of formic or butyric acid and oxide and of the dry basic salt of divalent metal, the oxide or hydroxide of Zn 2+ or Cu 2+ , to give an exothermic reaction, without addiction of solvents, giving rise to a dry carboxylate of divalent metal that is easy to use. It also describes the use of a stage of mixing with metal aminoates or hydroxy analogs of methionine in the process, for forming either a carboxylate-aminoate of divalent metal or a carboxylate-methioninate hydroxy analog of divalent metal, products that are finally obtained in a dry form that is easy to use. Finally it describes the use of the compounds that can be obtained in the feeding of monogastric animals for improving the productivity, the bioavailability of the metals, and achieve a reduction of their emission to the environment, owing to the growth-promoting effect that they all display.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/EP2007/002509, filed Mar. 21, 2007, which designated the United States, and claims the benefit under 35 USC §119(a)-(d) of German Application No. 20 2006 004 718.2 filed Mar. 22, 2006, the entireties of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a device for influencing the movement of furniture parts which can be moved with respect to one another, and to a piece of furniture.
BACKGROUND OF THE INVENTION
[0003] Devices are already known for influencing furniture parts which can be moved with respect to one another and can be moved, in a driven manner, relative to one another with the aid of a guide unit and with respect to one another by means of a drive unit. By way of example, toothed belts which revolve between two toothed wheels which are spaced from one another are used to transmit a drive effect from the drive unit to the furniture part to be moved, for example a drawer, in which case one of the toothed wheels can be driven.
[0004] An arrangement such as this requires a comparatively large amount of physical space, is relatively complex to produce and, furthermore, requires intensive maintenance and is susceptible to defects.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is to provide a device for the movement of furniture parts which can be moved relative to one another, and to provide a piece of furniture having a device such as this, in particular with the aim of the device having a particularly compact design and being simple to install, and making it simple to compensate for the discrepancies which occur from an ideal installation situation for the device.
[0006] First of all, the invention is based on a device for influencing the movement of furniture parts which can be moved with respect to one another, having a guide unit for guidance of a first furniture part on a second furniture part, and having a drive unit by means of which the first furniture part can be moved, in a driven manner, relative to the second furniture part. The guide unit has a fixed rail, which is associated with the second furniture part, and a moving rail, which is associated with the first furniture part. One major aspect of the invention is that a pulling-pushing element is provided in order to apply a drive effect from the drive unit to the first furniture part, guided on the fixed rail via guide means. A pulling-pushing element which can be moved by the drive unit makes it possible to produce a device for influencing the movement of furniture parts which can be moved relative to one another, for the driven movement of at least one furniture part, in a comparatively very compact and space-saving manner. In particular, the pulling-pushing element results in a simple transmission means, which operates particularly reliably, for a to-and-fro movement. Furthermore, virtually all movement patterns of furniture parts which can be moved relative to one another can advantageously be carried out by a to-and-fro movement of a transmission element. In this case, it is particularly advantageous that a pulling-pushing element can transmit both relatively very high pushing and pulling forces, even over considerable distances, translationally and in the direction of its longitudinal extent. If required, the pulling-pushing element may be flexible or bendable, at least over sub-sections. This may be advantageous with respect to spatial orientations which have to be set up differently and/or for transmission of the drive effect in different directions, and for the necessary space requirement for the pulling-pushing element. In particular, the comparatively slimline pulling-pushing element makes it possible to dispense with complex devices for switching and/or deflection of the transmission means.
[0007] The guide means allow the guidance for the pulling-pushing element to be designed to be comparatively simple and space-saving, advantageously making use of the fixed rail which is provided in any case. This is advantageous with regard to the device for influencing movement being designed to be as lightweight and slim as possible. In addition, this means that there is no need to modify the moving rail for the guidance of the pulling-pushing element. At the end, the pulling-pushing element is firmly fitted to the position member, by means of the part which projects out of the guide. The pulling-pushing element is thus accommodated in the guide on the fixed rail, and therefore most of the time in a space-saving manner, when the movable furniture part is in the closed or moved-in position. In principle, guide means can also be provided for guidance of the pulling-pushing element on the moving rail.
[0008] Furthermore, when using a pulling-pushing element, it is particularly advantageously possible to achieve relatively low friction losses between the moving pulling-pushing element and adjacent sections. This makes it possible to produce an apparatus for influencing movement which is subject to particularly little wear, requires particularly little maintenance, or is maintenance-free. The device for influencing movement is accordingly distinguished by reliability and robustness which are high overall. This advantageously makes it possible to achieve a large number of load cycles without material failure, and to ensure that the device has a long expected life.
[0009] In addition, the movement can be transmitted to the furniture part to be moved by means of a pulling-pushing element according to the invention with comparatively few parts, which reduces cost.
[0010] A cable-like part or a partially flexible part has been found to be particularly advantageous for the pulling-pushing element. This is advantageously designed completely identically, or is designed to have different flexibility or to be stiff in subsections. For example, in a subsection which is deflected in order to apply the drive effect, for example, a pulling-pushing element may be flexible or bendable to a certain extent, while it may be virtually stiff or rigid, for example in the form of a pushing-pulling rod, in another subsection. Various plastics may also be used as the material for the pulling-pushing element, in addition to metallic cables or wire meshes, or metal rods.
[0011] In order to transmit force and movement from the drive unit, and/or a transmission unit, to the pulling-pushing element, the latter may be provided, for example, with a matching shape and/or contour, for example with a profiled outside, via which the necessary forces can be transmitted from the drive unit to the pulling-pushing element, moving the latter to and fro. By way of example, the pulling-pushing element may advantageously be provided with helical or thread-like outsides, which make an engaging contact with corresponding mating sections of a drive or transmission part, in order to transmit force. The drive effect is therefore transmitted in particular in a very confined space and without additional parts. In addition to the simple drive, this also elegantly allows switching between two opposite movement directions of the pulling-pushing element in its longitudinal alignment. For example, a rising cable with an additional pushrod or without a pushrod connected to it in the longitudinal direction can be provided as the pulling-pushing element.
[0012] A further major aspect of the invention is that adjusting means are provided for adjustment of the position of a position member on the moving rail, on which position member the pulling-pushing element acts in order to apply the drive effect to the first furniture part. The first furniture part, which is to be moved by the pulling-pushing element, can particularly advantageously be achieved by a drivable movement of the moving rail. Since the moving rail is generally produced separately and is fitted as a separate unit to the complete first furniture part, the movement transmission can be set up independently of the nature and/or the presence of the first furniture part, or of the drawer, on the moving rail. This can be particularly advantageous when using standardized moving rails, which are used for different furniture models. The absolute position of the movable furniture part relative to the second or stationary furniture part is therefore also determined by the position member, via the pulling-pushing element. The capability to adjust the position member can be used, in particular in the case of a completely assembled guide unit and/or of the furniture parts which interact with it, to provide fine adjustment in this state in order to achieve exact alignment and/or a separation position and/or angle position of the furniture parts with respect to one another, preferably when the movable furniture part is in defined stationary positions, for example in the completely open or completely closed position. This is because, particularly as a result of discrepancies in the actual installation positions from ideal installation positions, fine adjustment of the prefitted movable furniture part with respect to the furniture part which is fixed with respect to it and the position of the movable furniture part in relation to adjacent furniture parts or objects is particularly helpful. Particularly, for example, when the movable furniture part is in a stationary state which, for example, the drive unit defines as a closed position, it is desirable to adjust the position at which the pulling-pushing element acts, since the movable furniture part is located in this position most of the time and, for example, alignment errors in the closed position are visually particularly conspicuous and are considered to have a particularly negative effect. In this case, during movement of the movable furniture part, fine adjustment is possible via at least two points of action, for example by means of two pulling-pushing elements, thus in particular allowing mechanical matching for example of a left-hand and right-hand drawer guide independently of one another, for example for parallel alignment of a drawer front with respect to a furniture housing edge.
[0013] The adjustment of the position member on the moving rail also makes it possible at any time to compensate for any minor position shifts which may occur of the relevant parts during operation, which can lead to a position error of the movable furniture part.
[0014] For example, a corresponding furniture front, which comprises a plurality of drawers which are positioned one above the other and/or at the side of one another, and which must be aligned exactly with respect to one another in their closed final position, can be created in an uncomplicated form by means of the proposed position member and the pulling-pushing element which acts on it.
[0015] The adjusting means are preferably designed such that the adjustment is carried out by movement of the position member parallel to the longitudinal direction of the pulling-pushing element. For this purpose, the pulling-pushing element just has to be set back or set forward by means of the position member in its longitudinal direction in order to allow the adjustment of the position of the position member, and therefore of the position of the first furniture part relative to adjacent objects. This can be achieved without any further measures, since the pulling-pushing element can be moved or shifted in its longitudinal direction in any case, and can compensate for minor separations at any time.
[0016] In principle, in an alternative or additional variant, the adjustment or depth adjustment of a drawer front in a furniture housing is also possible within the pulling-pushing element, for example at the coupling point between a rising cable and a pushrod which is connected to it directly or via an intermediate element.
[0017] In one preferred refinement of the device according to the invention, the adjusting means are designed such that adjustment is possible when the guide unit is in the state in which it is mounted ready for use on the furniture parts. This allows readjustment or fine adjustment of the position member, and therefore of the movable furniture part, in particular after initial fitting has been carried out. This may also be advantageous for movable furniture parts which are operated frequently. Minor position shifts which may occur as a result of the frequent movement of the first furniture part can thus be compensated for. In particular, the adjusting means are positioned such that they are easily accessible and can be operated easily, for example from an operating face of the movable first furniture part.
[0018] The adjusting means are advantageously designed for continuously variable adjustment of the position member. This makes it possible to achieve even very small adjustment movements of the position member, for example in the region of fractions of a millimeter or of a few millimeters. This may be particularly advantageous for large-area front parts of the movable furniture part where even very minor discrepancies from an ideal position with respect to adjacent furniture parts or housing edges can be visually perceived by the human eye, and are found to be annoying.
[0019] In a further advantageous refinement of the subject matter of the invention, the adjusting means are formed on an end section, viewed in the longitudinal direction, of the moving rail. By way of example, a front end section of the moving rail, which is accommodated in a furniture housing, may just need to be moved relatively slightly from the closed position in order to allow access to the front part of the moving rail or to allow the adjusting means to be operated.
[0020] In this case, according to the invention, it is particular advantageous that the transmission of the drive effect to the movable furniture part does not require any direct connection to the movable furniture part itself, but is achieved by the driven movement of the moving rail. This therefore allows the drawer to be removed from the guide unit, in particular without the use of any tools, and to be fitted again later without any problems, in order to allow the adjusting means to be operated better. In this case, the installed guide unit can remain completely in its installed state.
[0021] The position member advantageously comprises an adjusting slide which is held, such that it can move, on a guide part. The adjusting slide can therefore be accommodated in a protected manner and, for example, can be moved in fine steps or continuously variably, or can be moved such that it can be shifted with comparatively small forces, via guide sections, which are matched to one another, on the guide part and on the adjusting slide.
[0022] In one preferred embodiment of the device for influencing movement, the adjusting means are fitted as a separate unit to the moving rail. This allows this unit to be replaced, assembled and disassembled again without any problems, as is particularly desirable for maintenance and initial installation purposes. The adjusting means can be fitted directly to the moving rail, or can be connected indirectly to the moving rail via an intermediate piece.
[0023] It is also proposed that the guide part can be fitted to the moving rail via a detachable securing means. This allows the position member to be fitted to and removed from the moving rail quickly. The guide part is advantageously fitted to a particularly easily accessible part of the moving rail, for example to a front or rear end of the moving rail.
[0024] In a further advantageous refinement of the subject matter of the invention, the adjusting slide has a threaded section with which a matching opposing thread on a control part can interact in order to adjust the adjusting slide. The adjusting slide can be adjusted in finely graduated steps by means of a threaded section and a matching opposing thread. For example, the control part can be provided with an external thread which can engage in an internally threaded section of a depression in the adjusting slide. For example, a screw with a head which is fixed in its longitudinal direction in the position member can be used as a control part, and can be screwed into and out of a cylindrical internal thread in the adjusting slide. The adjusting slide can therefore be moved forwards or backwards, depending on the rotation direction, by rotation of the screw with a head.
[0025] It is also proposed that the guide means for guidance of the pulling-pushing element comprise a part which can be detachably plugged onto the fixed rail. This allows the fixed rail to be installed and assembled in a modular form conveniently. This may be advantageous, for example, when standardized base bodies are used for fixed rails on which guide means can be selectively fitted for guidance of the pulling-pushing element. Alternatively, the part can also be removably fitted to the fixed rail by being clipped on, pushed on or pivoted in.
[0026] The guide means advantageously comprise a slotted guide profile, in particular a hollow profile which is slotted in the longitudinal direction. This makes it possible to achieve an arrangement which is particularly space-saving and comprises relatively few parts. In this case, by way of example, the pulling-pushing element may be in the form of a flexible rising cable, in particular without a pushrod, which acts via a driver element, which is provided on the moving rail, thereon. This pulling-pushing element can thus, for example, be connected to a rear end of a drawer rail. The guide profile is designed to be slotted, in order to drive the pulling-pushing element which can be moved to and fro in the guide profile.
[0027] In addition, the invention covers a device for influencing the movement of furniture parts which can be moved with respect to one another, having a guide unit for guidance of a first furniture part on a second furniture part, and having a drive unit by means of which the first furniture part can be moved, in a driven manner, relative to the second furniture part, with the guide unit having a fixed rail, which is associated with the second furniture part, and a moving rail, which is associated with the first furniture part. One major aspect of the invention is that a part which can be detachably plugged onto the fixed rail has holding areas for line means. This advantageously makes it possible to achieve additional functions on the part which can be plugged on. For example, connecting lines for electrical additional elements can be accommodated in the part which can be plugged on, for example electrical supply lines for lighting elements or other electrical devices in the furniture part. The part can also be fitted by being clipped on, pushed on or pivoted in.
[0028] The invention also relates to a device for influencing the movement of furniture parts which can be moved with respect to one another, having a guide unit for guidance of a first furniture part on a second furniture part, by means of which guide unit the first furniture part can be moved relative to the second furniture part, with the guide unit having a fixed rail, which is associated with the second furniture part, and a moving rail, which is associated with the first furniture part. One fundamental idea of the invention comprises a part which can be detachably fitted to the fixed rail in order to accommodate line means. This also allows precautions to be taken for the device to be fitted with line means quickly and selectively, for the abovementioned devices as well.
[0029] The invention is also based on a piece of furniture having a first furniture part which can be moved relative to a second furniture part, in particular having a drawer which can be moved in a housing, in a driven manner, via a drive unit, with a guide unit being provided for guidance of the first furniture part on the second furniture part. In this case, the furniture part has one of the abovementioned devices according to the invention, thus making it possible to achieve the described advantages on the piece of furniture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Further features and advantages of the invention are illustrated, using various exemplary embodiments, in the figures of the drawings.
[0031] FIG. 1 shows a perspective view obliquely from above of a basic profile of a housing rail of a drawer guide with a guide profile with a pulling-pushing element guided in it;
[0032] FIG. 2 shows an enlarged detailed view from FIG. 1 , showing the detail A,
[0033] FIG. 3 shows a front view of the front end of the arrangement shown in FIG. 1 ,
[0034] FIG. 4 shows a perspective view of a section transversely with respect to the longitudinal extent of the arrangement shown in FIG. 1 , along the line I-I in FIG. 1 ;
[0035] FIG. 5 shows a perspective view of a housing rail of a drawer guide with guide devices fitted to it, for guidance of a pulling-pushing element, and a supply line;
[0036] FIG. 6 shows a perspective view of a part of one of the guide devices shown in FIG. 5 ;
[0037] FIGS. 7 to 9 show alternative refinements of that part of a guide device which is shown in FIG. 6 ;
[0038] FIG. 10 shows a perspective view of the front end of the pulling-pushing element, as shown in FIGS. 1 to 4 ;
[0039] FIGS. 11 and 12 show an adjusting part in the form of a perspective view obliquely from behind and obliquely from in front;
[0040] FIG. 13 shows a longitudinal section of the adjusting part shown in FIGS. 11 and 12 ;
[0041] FIG. 14 shows a perspective view of a part of the adjusting part illustrated in FIGS. 11 to 13 ;
[0042] FIG. 15 shows a perspective view of the adjusting part shown in FIGS. 11 to 13 , with a pulling-pushing element acting on it;
[0043] FIG. 16 shows a perspective view of the front part of the arrangement shown in FIG. 1 and FIG. 2 with a fitting element fitted to it, in which an adjusting part as shown in FIGS. 11 to 13 is positioned;
[0044] FIG. 17 shows the arrangement as shown in FIG. 16 , but with the fitting element omitted;
[0045] FIG. 18 shows the fitting element as shown in FIG. 16 , with an adjusting part plugged in but not fixed;
[0046] FIG. 19 shows the arrangement as shown in FIG. 18 with an adjusting part, fixed by rotation, in the fitting element;
[0047] FIG. 20 shows a perspective partial view of a drawer guide of an alternative refinement of the device according to the invention for influencing the movement;
[0048] FIG. 21 shows a further perspective view of the arrangement shown in FIG. 20 , in the form of a perspective view obliquely from the rear;
[0049] FIG. 22 shows a further perspective partial view of the drawer guide as shown in FIGS. 20 and 21 , in the drawn-in state, with holding jaws being shown on a housing rail;
[0050] FIG. 23 shows a piece of furniture with a drawer which is held in a housing with a device according to the invention; and
[0051] FIGS. 24 a and 24 b show a highly simplified outline sketch of a horizontal section through a drawer, which is held in a housing as shown in FIG. 20 , with an installation position error of a guide unit, and in an installed state which has been corrected according to the invention with respect to this.
DETAILED DESCRIPTION OF THE INVENTION
[0052] FIG. 1 shows a base-rail part 1 , which comprises a bent-around sheet-metal section, for a housing rail, which is known per se, of a drawer guide. A drawer guide such as this comprises, in particular, a right-hand and a left-hand drawer guide unit, each having a drawer rail which is attached to a drawer and having a housing rail which is firmly fitted to a housing, possibly with a center rail arranged in between.
[0053] When the base-rail part 1 is in the installed position, a guide profile 2 is fitted to it at the top, in which a movement rod 3 of a pulling-pushing element is accommodated. This pushrod 3 may, for example, be composed of a cylindrical hollow material, in particular composed of metal or plastic. The movement rod 3 is held in a cylindrical elongated hole 4 such that it can move in the longitudinal direction of the movement rod 3 or translationally, or is guided in the form of a journal bearing. A comparatively narrow separating gap can be provided for this purpose between the outside of the movement rod 3 and the elongated hole 4 . The movement rod 3 can be moved axially to and fro, as indicated by the arrow P 1 in FIG. 2 , in the elongated hole 4 , in particular with comparatively very little friction.
[0054] The front end section of the movement rod 3 has a pin 5 whose external diameter is less than that of the movement rod 3 and which has a plug-in contour. In this case, by way of example, two opposite rounded outer surfaces 5 a and, between them, two opposite plane-parallel, flattened outer surfaces 5 b . As shown in particular in FIGS. 2 to 4 , the guide profile 2 is in the form of a structure body which is provided with cavities in places and can be detachably fitted, for example, to the base-rail part 1 , for example by being plugged on, clipped on, pushed on or pivoted in. For this purpose, by way of example, sheet-metal lugs 6 which are bent upwards on the upper face of the base-rail part 1 can engage in grooves 7 , appropriately matched to them, on the lower face of the guide profile 2 , to provide firm clamping. The sheet-metal lugs 6 may, for example, be in the form of slotted sheet-metal flaps composed of the sheet-metal material of the base-rail part 1 . The number, shape and distribution of the sheet-metal lugs 6 over the length of the base-rail part 1 may be as required, and, for example, they can be arranged offset with respect to one another or may be chosen such that the width of the sheet-metal lugs is different. The sheet-metal lugs 6 in the base-rail part 1 are advantageously designed such that the base-rail part 1 is not significantly mechanically weakened and there is no disadvantageous influence on the movement of a carriage on rollers running on the base-rail part 1 . By way of example, the guide profile 2 may be pushed onto the base-rail part 1 from the front or rear, with the walls of the grooves 7 clasping the sheet-metal lugs 6 , partially resting on them, so as to allow secure and firm positioning of the guide profile 2 on the base-rail part 1 . As is shown in FIG. 1 , the guide profile 2 may be formed over the entire length of the base-rail part 1 , but may also be provided thereon just in places, and possibly in more parts.
[0055] In addition, further closed or open cavities, for example 8, 9 and 10, are formed in the interior of the guide profile 2 , and additional elements can be accommodated in them. By way of example, the cavity 10 can be used to accommodate a supply cable for a light source and, for this purpose, is in the form of a profile, which is open at the front and rear, and/or is provided with a slot 10 a over its length. The cavities, for example 8 and 10, allow the guide profile 2 to be formed with the aid of appropriate strut structures such that on the one hand it is comparatively robust, while on the other hand it is designed to be relatively lightweight.
[0056] By way of example, FIG. 4 shows the movement rod 3 in the form of a hollow cylinder. The movement rod may, however, also have a different shape or else may be composed of solid material.
[0057] FIG. 5 shows a further embodiment of a guide profile 11 according to the invention on a housing rail 12 . The housing rail 12 also comprises a further guide profile 13 which is designed in a corresponding manner to the guide profile 2 shown in FIGS. 1 to 4 . In order to fit the housing rail 12 to a housing, fitting jaws 12 a , 12 b , which are in the form of sheet-metal brackets, are attached to a lower face of a base-rail part 14 . The guide profile 11 essentially comprises a guide tube 15 in which, for example, a pulling-pushing element can be guided such that it can move, and other elements can be accommodated if required. In this case, by way of example, two adaptor elements 16 , 17 are plugged onto the fitting jaws 12 a , 12 b for attachment, support and guidance of the guide tube on the housing rail 12 . In principle, just one adaptor element or else even more adaptor elements can also be fitted to the housing rail 12 .
[0058] FIG. 6 shows a perspective view of the adaptor element 16 , which is designed to be identical to the adaptor part 17 . The adaptor element 16 can be plugged from below onto a bent-around sheet-metal limb of the fitting jaws 12 a , 12 b , by means of two latching tabs 18 which are fitted to the adaptor element 16 at the end. In this case, the latching tabs 18 spring slightly open and, after clasping the sheet-metal limbs, snap into a fixed latching position on the fitting jaws 12 a , 12 b . The adaptor element 16 is plugged onto the fitting jaw 12 a in an area of the sheet-metal limb of the fitting jaw 12 a which is formed at the side on the base-rail part 14 as far as a bend of the fitting jaw 12 a , between the sheet-metal limbs which are angled away from one another.
[0059] The adaptor element also has a guide channel 19 in which the inserted part of the guide tube 15 is accommodated, and/or the adaptor element 16 also has a spring section 20 , which is formed approximately centrally and, in particular, allows length compensation of the adaptor element 16 in its longitudinal direction. The spring section 20 is used to match the length of the adaptor element 16 to the respective width of the sheet-metal limb of the fitting jaw onto which the adaptor element 16 is plugged. This advantageously makes it possible to achieve fitting jaw dimensions which are used differently, with an adaptor element of identical design. A contact edge 21 is provided for secure positioning of the adaptor element 16 in the bent-around area of the fitting jaw 12 a , and rests on the bend on the fitting jaw 12 a.
[0060] FIG. 7 shows an alternative refinement of an adaptor element 22 , in which, in this case, there is no spring section for length compensation for the adaptor element 22 .
[0061] Further alternative adaptor elements 23 and 25 , which are of similar design to the adaptor elements 16 , 17 , are shown in FIGS. 8 and 9 . In this case, the adaptor element 23 has a spring section 24 , and the adaptor element 25 has a spring section 26 . For this purpose, at least in the area of their spring sections 23 , 24 and 26 , the adaptor elements 16 , 17 , 23 and 25 are formed in particular with recesses and using an appropriately suitable material, for example being composed of a plastic or a material with elastic characteristics.
[0062] In principle, the adaptor elements 16 , 17 , 22 , 23 and 25 may also be attached to the base-rail part 1 in a corresponding manner to that in which the guide profile 2 is fitted.
[0063] FIG. 10 illustrates a detail of the front section of the movement rod 3 as shown in FIGS. 1 to 4 . In order to fix the movement rod 3 and in order to link it in a simple manner to a drawer rail for its to-and-fro movement, an adjusting member 30 is formed, for example, on the drawer rail, at its front end pointing towards an operating face. The adjusting member 30 comprises an adjusting ring 31 ( FIG. 14 ) which is guided such that it can move thereon and has an insertion opening 32 for the pin 5 of the movement rod 3 . The wall of the insertion opening 32 is matched to the external contour of the pin 5 such that the pin 5 can engage in the insertion opening 32 with little play. This can be seen in particular from FIG. 15 , which shows the adjusting member 30 with a movement rod 3 inserted in it. FIG. 15 does not show the necessary fixing or attachment for the movement rod 3 to the adjusting member 30 . This could, for example, be provided by a fixing screw (not illustrated), which is screwed in on one end surface 5 c of the pin 5 and which prevents the movement rod 3 from being pulled out of the adjusting ring 31 . The pin 5 can also be pressed, welded, adhesively bonded, crimped, pinned or fixed in a manner such as this in the insertion opening 32 .
[0064] The adjusting ring 31 also comprises a hole 33 with an internal thread 33 a . The internal thread 33 a allows the adjusting ring 31 to be moved in the adjusting member 30 , and in particular to be moved forwards and backwards, by means of an adjusting screw 34 which is likewise part of the adjusting member 30 . For this purpose, the adjusting ring 31 is held, such that it can move, in an adjusting sleeve 35 of the adjusting member. The adjusting screw 34 can likewise be rotated in the adjusting sleeve 35 , but is held firmly fixed in its longitudinal direction. This can be achieved, for example, by means of contact tabs 36 and a contact section 37 in an aperture opening 38 in the adjusting sleeve 35 . In order to achieve a cleanly guided shifting movement of the adjusting ring 31 by rotation of the adjusting screw 34 , the adjusting ring 31 is guided with its outside on profiled guide sections of the aperture hole 38 . For this purpose, by way of example, guide webs 39 and guide surfaces 40 which run in the aperture opening 38 are formed along the aperture opening 38 .
[0065] As can be seen in particular from FIG. 11 , the adjusting ring 31 can be pivoted about its longitudinal axis over a certain angle range as required in the aperture opening 38 , for example over an angle range of about 30 degrees of angle. If appropriate, this makes it possible to compensate for any minor position compensation movements which may occur between the movement rod 3 and the drawer rail, in particular when the majority of the movement rod 3 has been moved out of the elongated hole 4 in the guide profile 2 when the drawer is pulled partially or entirely out (with reference to FIGS. 1 to 4 ).
[0066] The adjusting sleeve 35 may approximately assume a cylindrical external shape and, for example, for material saving reasons and/or in order to reduce weight, may be provided with cavities 41 . In order to allow simple replacement and for detachable fixing of the adjusting member 30 on the drawer rail, a fitting element 43 may, for example, be provided preferably at the front end of the drawer rail (see FIGS. 16 , 18 and 19 ). The fitting element 43 illustrated in FIG. 16 is shown in its installed position on the drawer rail with the drawer rail moved back and with the drawer in the closed state which is correspondingly reached in this way. The drawer rail itself is not illustrated, but, for example, is formed from profiled sheet-metal material, particularly in a manner corresponding to known drawer rails. The fitting element 43 can be fixed to the drawer rail preferably via sprung latching jaws 44 which can latch detachably into corresponding mating sections on the drawer rail. As illustrated by the arrow P 2 in FIG. 16 , the fitting element 43 can be moved together with the drawer rail, which is not illustrated, with respect to the stationary base-rail part 1 and the guide profile 2 which is attached to it. This to-and-fro movement is carried out by the driven movement of the drawer rail and thus of the drawer by means of the movement rod 3 of the pulling-pushing element. The to-and-fro movement of the pulling-pushing element is provided by a drive unit, which is not illustrated. As described above, the movement rod 3 is connected to the fitting element 43 via the adjusting member 30 which is fixed in the fitting element 43 (see FIG. 16 ).
[0067] The movement capability for the drawer rail and if required a center rail with respect to the housing rail and/or the base-rail part 1 can be provided in particular by means of an arrangement which is known per se, for example by means of a roller carriage with bearing bodies.
[0068] In order to provide a better illustration of the coupling of the pulling-pushing element and of the movement rod 3 to the drawer rail and to the adjusting member 30 , respectively, FIG. 17 shows only the base-rail part 1 with the guide profile 2 fitted to it, and the movement rod 3 accommodated therein, as well as the adjusting member 30 , which is firmly fitted to the movement rod 3 .
[0069] In order to fit the adjusting member 30 to the fitting element 43 , and to remove it, two latching vanes 42 , which are opposite one another with respect to the longitudinal axis of the adjusting member 30 , are integrally formed on a cylindrical outer face of the adjusting sleeve 35 . In addition, an installation opening 45 is provided from the front or the installation side on the fitting element 43 , in which installation opening 45 the adjusting member 30 can be inserted such that it fits, in which case the latching vanes 42 can be inserted into the installation opening 45 only when the adjusting member is in the installed position, for example when the adjusting member 30 is in a position in which the latching vanes 42 are positioned approximately vertically one above the other, as can clearly be seen in particular in FIG. 18 . The adjusting member 30 , which is inserted into the fitting element 43 in this position, can be pushed in as far as a stop, which is not illustrated in any more detail, in the installation opening 45 and can be moved to a latching position in the fitting element 43 in this stop position by rotation of the adjusting member 30 or of the adjusting sleeve 35 , as is illustrated in FIG. 19 . By way of example, in this latching position, the latching vanes 42 are each held firmly, clamped in place, in a cut-out gap 46 in the fitting element 43 (see FIG. 16 ).
[0070] FIGS. 20 and 21 show side perspective views of a part of a drawer guide according to the invention with a guide profile 47 which is plugged onto a base-rail part 48 of a housing rail. The drawer guide also includes a center rail 49 and a drawer rail 50 . In addition, a drive shaft 51 with a toothed wheel 52 is illustrated schematically, by which means, when the toothed wheel 52 makes contact, forming an engagement, with a rising cable 53 , this can be moved backwards and forwards, in a driven manner, in the guide profile 47 . In order to transmit the shift movement via the rising cable 53 from a drive unit, which is not shown, a driver 54 is fitted to the drawer rail 50 , mounted at its rear end. The driver 54 is connected to the rising cable 53 such that, during a shifting movement of the rising cable 53 in the guide profile 47 , the driver 54 and thus the drawer rail 50 can be moved past on the guide profile 47 .
[0071] The position of the drawer rail 50 when the drawer is in the completely moved-back position or in the closed position, with the drawer being attached to the drawer rail 50 (not illustrated), is shown in FIG. 22 . In this case, the driver 54 at the rear end of the guide profile 47 has been moved back away from the position illustrated in FIG. 20 .
[0072] FIG. 23 shows, obliquely from above, a piece of furniture 55 according to the invention, which comprises a housing 56 and a drawer 57 which is guided such that it can move therein. The drawer 57 , which is arranged in the lower area of the housing 56 , is illustrated in the open or pulled-out state, with the furniture parts 56 , 57 which can be moved with respect to one another being movable with respect to one another via a pulling-out fitting or a drawer guide 58 . A further drawer, which is not illustrated, can be accommodated in the same way in the housing 56 via a further drawer guide 58 a . The drawer 57 can be pulled out or pushed in relative to the housing 56 , as indicated by the double-headed arrow P 3 . In order to hold and/or guide the movement of the drawer 57 , an identical drawer guide 58 is in each case accommodated in the lower area of drawer frames 57 a , which project upwards on both sides on a drawer bottom 57 c , with the drawer guide 58 or 58 a being illustrated in FIG. 1 only on one inner face of the housing, in each case. The drawer 57 can be driven, in which case, for example, the drive unit can be arranged in the rear area of the housing and/or of the guide 58 (although this cannot be seen here).
[0073] FIG. 24 a shows a view, in the form of a sketch, of a piece of furniture as shown in FIG. 23 , from above. In this case, side walls 59 and a front edge 60 of a furniture housing and right-hand and left-hand drawer guides 61 , 62 , which are mounted on the side walls 59 , are installed. The drawer guides 61 , 62 as shown in FIG. 24 a are illustrated in an exaggerated form, installed differently in the depth of the side walls 59 , as can occur, for example, if installed inaccurately. As a result of the discrepancy in the exact alignment of the installed position of the two drawer guides 61 , 62 in depth relative to the front edge 60 , a drawer front 63 of a drawer which is attached to the drawer guides 61 , 62 is positioned obliquely with respect to the front edge 60 . The right-hand and left-hand drawer guides 61 , 62 can each be adjusted independently of one another by means of the depth adjustment of the drawer guides 61 , 62 according to the invention from the inclined front position of the drawer front 63 with respect to the housing, as shown in FIG. 24 a . The depth adjustment is carried out by adjustment of the pulling-pushing element, which acts on drawer rails of the drawer guides 61 , 62 . The drawer front 63 can thus be aligned parallel to the front edge 60 as shown in FIG. 24 b . By way of example, in the case of the drawer guide 61 which is illustrated in FIG. 24 a , the point at which the pulling-pushing element acts on the drawer rail can be enlarged in the longitudinal direction of the drawer guide 61 . On the other hand, the point at which the pulling-pushing element acts on the drawer rail of the drawer guide 62 can be reduced along the drawer guide 62 .
LIST OF REFERENCE SYMBOLS
[0074]
[0000]
1
Base-rail part
2
Guide profile
3
Movement rod
4
Elongated hole
5
Pin
5a
Outer surface
5b
Outer surface
5c
End surface
6
Sheet-metal lug
7
Groove
8
Cavity
9
Cavity
10
Cavity
10a
Slot
11
Guide profile
12
Housing rail
12a
Fitting jaw
12b
Fitting jaw
13
Guide profile
14
Base-rail part
15
Guide tube
16
Adaptor element
17
Adaptor element
18
Latching tab
19
Guide channel
20
Spring section
21
Contact edge
22
Adaptor element
23
Adaptor element
24
Spring section
25
Adaptor element
26
Spring section
27
Unused
28
Unused
29
Unused
30
Adjusting member
31
Adjusting ring
32
Insertion opening
33
Hole
33a
Internal thread
34
Adjusting screw
35
Adjusting sleeve
36
Contact tab
37
Contact section
38
Aperture opening
39
Guide web
40
Guide surface
41
Cavity
42
Latching vane
43
Fitting element
44
Latching jaw
45
Installation opening
46
Holding gap
47
Guide profile
48
Base-rail part
49
Center rail
50
Drawer rail
51
Driveshaft
52
Toothed wheel
53
Rising cable
54
Driver
55
Piece of furniture
56
Housing
57
Drawer
57a
Drawer frame
57b
Drawer frame
57c
Drawer bottom
58
Drawer guide
58a
Drawer guide
59
Side wall
60
Front edge
61
Drawer guide
62
Drawer guide
63
Drawer front
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The invention relates to a piece of furniture and to a device for influencing the movement of furniture parts which can be moved with respect to one another, having a guide unit for guidance of a first furniture part on a second furniture part, and having a drive unit by means of which the first furniture part can be moved, in a driven manner, relative to the second furniture part, with the guide unit having a fixed rail, which is associated with the second furniture part, and a moving rail, which is associated with the first furniture part. A pulling-pushing element is provided in order to apply a drive effect from the drive unit to the first furniture part, guided on the fixed rail via guide means.
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FIELD
[0001] The invention relates to a valve for ensuring equalisation of pressures between two sub-chambers of a hydraulic damper. The invention furthermore relates to a hydraulic damper.
BACKGROUND
[0002] Generic hydraulic dampers serve to dampen impacting forces such as impacts on structural elements. Generic hydraulic dampers are, for instance, used to dampen vibrations in structures such as bridges or high rise buildings that may occur during earthquakes. Hydraulic dampers are, for instance, used for this purpose in cable dampers. Generic hydraulic dampers are designed to mitigate the danger that sudden impact may separate supporting structural elements. Generic hydraulic dampers are correspondingly designed to dampen such impacts. Due to the considerable forces occurring in the area of application of such hydraulic dampers, these dampers must be constructed particularly robust to be able to dampen extremely high forces. Over and above this, such hydraulic dampers are also required to be particularly robust and reliable and this must be taken into consideration in the design of such hydraulic dampers.
[0003] Generic hydraulic dampers generally have a working chamber with a sliding piston dividing the working chamber into two sub-chambers, viz. a first and a second sub-chamber. The piston will have a fluid line with a small cross-section connecting the two sub-chambers to allow the flow of fluid between said sub-chambers. The hydraulic damper is to be fitted between the elements of two structures to be dampened against each other with the piston fastened to the first structural element and the enclosure with the working chamber fastened to the second structural element. The working chamber is filled with a hydraulic fluid. A force acting to cause relative movement between the two structural elements will slide the piston in the working chamber to thereby change the ratio of fluid volumes in the two sub-chambers. The small cross-section of the fluid line in the piston ensures dampening of the relative movement of the structural elements.
[0004] It has been found to be particularly advantageous to provide a valve in the fluid path to ensure that fluid only flows between the sub-chambers when a force between the structural elements or the relative speed of the structural elements exceeds a lower limit. This will prevent relative movement of the structural elements unless the force is correspondingly high, with the hydraulic damper allowing damped relative movement of the structural elements only in the event of a particularly high force. Conventional valves achieve this using two valve elements, one of which will be designed as a seat element and the other as a moving element. The seat element is rigidly attached to the piston and comprises at least one section of the fluid path. The moving element rests against the end of the seat element in a way as to close the fluid path when in rest position.
[0005] When in rest position, a spring system would normally exert a spring force pressing the moving element against the seat element or the fluid path. The moving element is displaced from its rest position when the pressure difference between the sub-chambers exceeds a lower limit, i.e. when the hydraulic damper is subjected to a force exceeding a lower limit. The pressure difference will in this case exert a force on the moving element that exceeds the force of the spring system, pressing said element away from the seat element to allow fluid to flow between the sub-chambers via the fluid path, i.e. from a first sub-chamber at high pressure to a second sub-chamber at a lower pressure.
[0006] Conventional hydraulic dampers, however, have the disadvantage that the valves will suddenly open when the force between the structural elements exceeds the lower limit, potentially causing jerking displacements of the structural elements. In addition, conventional hydraulic dampers are only suited for damping forces between the structural elements they are attached to if those forces remain within a certain limited range. This is because the valves in the piston will not open if the force on the hydraulic damper is too low and the piston then cannot or can hardly move in its working chamber, with no damping effect. If hydraulic dampers experience a very large force, then conventional hydraulic dampers will not allow adequate relative displacement of the construction elements, since they cannot follow large forces fast enough to prevent structural damage.
[0007] This inherent problem with conventional hydraulic dampers is due to the fact that the design of hydraulic dampers is subject to a compromise with regard to setting the minimum force beyond which damping will be ensured and setting the resilience of the hydraulic damper in case very large forces are applied.
SUMMARY
[0008] The aim of the invention is to provide a valve that will ensure pressure compensation between the sub-chambers of a hydraulic damper and that will at least partially remedy the aforementioned problems and disadvantages of conventional valves. The invention furthermore aims to provide a hydraulic damper that will at least partially remedy the disadvantages of conventional hydraulic dampers.
[0009] The present invention relates to a valve configured to ensure equalisation of pressures between sub-chambers of a hydraulic damper, wherein the valve comprises a first side for connection to a first sub-chamber and a second side for connection to a second sub-chamber, wherein the valve is designed in its rest position to block a flow of fluid between the two sides, and will open a through-flow path with a through-flow cross-section to allow a flow of fluid when displaced from its rest position, wherein valve comprises two mutually guided valve elements that are movable relative to each other in a direction of movement (x), wherein one of the two valve elements is designed as a moving element and the other valve element as a seat element, wherein the moving element is configured to be exposed on its load side to pressure of a fluid on the first side to create an effective displacement force acting on the moving element in the direction of movement (x), wherein the moving element is connected to a spring system to exert a restoring spring force opposing the effective displacement force on the moving element, characterised in that one of the valve elements includes a cylinder section with a plurality of passages, wherein the through-flow path passes through at least some of the passages and the cross section of the through-flow path is limited by a cross-section of these passages, wherein the other valve element comprises a closed cylinder shell section that at least in the rest position rests against the first valve element to block the flow of fluid, wherein the cross section of the through-flow path is adjustable via the excursion of the valve as a result of displacement of the moving element relative to the seat element in the direction of movement (x), wherein the cross section of the through-flow path will increase as the excursion increases.
[0010] The valve is designed to ensure pressure compensation between sub-chambers of hydraulic dampers. The valve is to this end designed to alternately allow and interrupt the flow of fluid between the sub-chambers of a hydraulic damper. The valve exhibits a first side to connect to a first sub-chamber and a second side to connect to a second sub-chamber of the hydraulic damper. The valve also is configured to block in its rest position the flow of fluid between the two sides, wherein the valve is configured to open a through-flow path with a through-flow cross-section for excursion from its rest position, to allow a flow of fluid. The fluid therefore passes through the through-flow path with its cross-section when the valve changes from its rest position. The valve according to the invention has two valve elements that are mechanically guided to each other to allow displacement relative to each other along a direction of movement. The two valve elements can slide relative to each other in particular, a very simple mechanical system to implement.
[0011] Curved displacement paths are also possible, however. The valve elements may be displaced relative to each other via a defined path. The two valve elements are embodied one as a moving element and the other as a seat element. The moving element may change position relative to the seat element by moving along a displacement path. The moving element and/or the seat element may be constructed as a single component.
[0012] The moving element is configured to be exposed on its load side to the pressure of a fluid on the first side, thereby effectively creating a force acting to displace the moving element in the direction of movement, wherein the moving element is connected to a spring system with the spring exerting a force on the moving element, thereby creating a restoring force in opposition to the effective displacement force. The valve is therefore constructed to allow a fluid on its first side to exert pressure in a way to allow the fluid to pass to the load side of the moving element and to allow exertion of an effective force to displace the moving element. The moving element in the valve may furthermore be designed to allow a fluid on the second side to exert pressure on its opposite side, which may be arranged facing the load side. The load side may, for instance, be facing the first side of the valve and the opposite side may be facing the second side.
[0013] The effective displacement force will naturally depend on the area over which the fluid on the first side can exert pressure on the moving element in the direction of movement. One component of the direction of movement will herein in particular have a direction connecting the first and second sides.
[0014] A difference between the pressure in the first sub-chamber on the first side of the valve and the pressure in the second sub-chamber on the second side of the valve will therefore with at least one component displace the moving element from the first sub-chamber to the second sub-chamber and thereby from the first to the second side of the valve. The effective displacement force may, for instance, be defined by the pressure exerted on the first side of the valve and the area on the load side facing the first side. Pressure may, for instance, be exerted on the valve element on the load side by fluid on the first side and on its opposite side by fluid on the second side, wherein the effective displacement force will be defined by the areas of the load and opposite sides and by the pressure difference on the two sides of the valve. The displacement force may, for instance, be defined by the pressure of fluid on the first side and the difference in the areas on the load and opposite sides if the moving element is subjected to fluid pressures on its load and opposite sides created by corresponding fluid lines to the first side.
[0015] The spring system may, for instance, be arranged on the opposite side of the moving element. The valve will in any event be constructed to ensure that the relative arrangement of the valve elements and the spring system will allow the spring to exert a restoring force on the moving element, especially with the valve in rest position, wherein the restoring force will oppose the effective displacement force that a fluid on the first side will exert on the moving element by applying pressure to the load side of the valve.
[0016] The seat element may, in particular, exhibit an end stop against which the spring system will press the moving element when in rest position.
[0017] At least one of the elements of the valve according to the invention has a cylinder section with a plurality of passages. This valve element may, for instance, be constructed as a hollow cylinder, wherein the passages are arranged in the cylinder shell. This valve element may, for instance, also be constructed as a solid cylinder, whereby the passages may be realised through axial grooves that may, for instance, run over a certain length of the cylinder section. The through-flow path in the valve according to the invention always includes at least some of the passages and the cross-section of the through-flow path will be limited by the cross-section of these passages that form part of the through-flow path. To be taken into account in this respect is that the cross-section of the through-flow path is negligibly small and the exchange of fluid between the two sides of the valve will therefore be nil to negligible. When the valve by excursion changes from rest position, a through-flow path with a certain cross-section will open, wherein the cross-section of the through-flow will be determined by the cross-section of the passages forming part of the through-flow path. The shape of the cross-section of these passages through which the through-flow path runs will limit the cross-section of the passages. The through-flow path, however, will not necessarily always utilise the full cross-section of a passage forming part of the through-flow path. The cross-section of a passage may be blocked at least partially, restricting the through-flow path to only a fraction of the full cross-section of the passage.
[0018] The cross-section of the passage will again in this case restrict the through-flow path cross-section, since the latter will be restricted by the shape of the passage cross-section. The through-flow path may obviously also include a passage with its full cross-section, wherein the cross-sectional area of that passage will then limit the cross-section of the through-flow path. The cross-section of the through-flow path may in particular also be defined by the sum of the contributions by cross-sections of passages forming part of the through-flow path.
[0019] The other element of the valve according to the invention has a closed cylinder shell section that in its rest position abuts one of the valve elements with the passages, blocking the flow of fluid. The closed cylinder shell section may, for instance, lie opposite at least some of the passages in one of the valve elements, allowing it to prevent fluid flow through the passages. The closed cylinder shell section need here not necessarily rest against the passages to thereby fully block fluid from flowing through the passages. The closed cylinder section of the other valve element may, for instance, be situated opposite the passages but spaced away somewhat to create a gap between the passages of the first valve element and the closed cylinder section of the other valve element. The closed cylinder shell section may, for instance, nevertheless block the flow of fluid between the two sides of the valve if this gap has closed boundaries in rest position, to prevent fluid from flowing between the two sides.
[0020] This may be ensured by resting the closed cylinder shell section against the one valve element.
[0021] The closed cylinder shell section is designed to rest against the one valve element when in rest position, thereby to block the flow of fluid. The closed cylinder shell section may, for instance, have a very short axial length and/or a cross-section comprising just a section of the cylinder base area. The closed cylinder shell section may represent a section of the shell of a cylinder with its axis lying in the direction of movement. The other valve element may, for instance, have a cylindrical opening in which the cylinder section with the passages of the first valve element will be positioned at rest, at least section by section. The cylinder section of the first valve element may, for instance, be constructed as a hollow cylinder within which a cylindrical section of the other valve element with a closed cylinder shell section will be positioned, at least when in rest position. The passages in the cylinder section of the first valve element may, for instance, be positioned to rest facing the closed cylinder section block in such a way that they will be closed. The passages in the cylinder section of the first valve element may, for instance, rest with the first side adjacent to the closed cylinder shell section of the other valve element. The closed cylinder shell section of the other valve element will in any event rest against the first valve element, in particular against the cylinder section of the first valve element containing the passages. Excursion of the valve from its rest position will fully or partially open the cross-sections of at least some of the passages. This is due to the fact that excursion of the valve from its rest position in the direction of movement will change the relative position of the closed cylinder shell section and the passages.
[0022] The flow of fluid between the two sides of the valve is thereby blocked when in rest position, since the closed cylinder shell section will prevent the fluid in the passages from flowing towards the other side. Fluid will, however, flow from one side of the valve to the other via the through-flow path between the two sides for excursion of the valve, wherein the through-flow path comprises those passages that are not blocked by the closed cylinder shell section.
[0023] A certain through-flow path with a certain through-flow cross-section will in any event open with excursion of the valve according to the invention from its rest position by a certain amount. The cross-section of the through-flow path opening with the excursion of the valve according to the invention when the position of the moving element relative to the seat element changes in the direction of movement, is adjustable, wherein the cross-section of the through-flow path will increase as the displacement increases. Various embodiments of the valve according to the invention will be evident to persons skilled in the art. The moving element may, for instance, be constructed as the valve element with the passages, with the other valve element designed as the seat element. The seat element may, for instance, be constructed as the valve element with the passages, with the other valve element designed as the moving element.
[0024] A person skilled in the art will see that a valve according to the invention will have the advantage that the through-flow path running via the passages and the adjustable cross-section of the through-flow path achieved through excursion of the valve from its rest position offers decisive advantages over conventional valves, with the corresponding advantages a hydraulic damper equipped with such a valve will have.
[0025] Because of the fact that the cross-section of the through-flow path increases as the valve excursion increases, a design may, for instance, provide that a through-flow path with a very small cross-section will open for slight excursions of the valve from rest position, ensuring that a small difference in pressures on the first and second side of the valve will enable a correspondingly low flow of fluid between the two sides, ensuring that damping will be commensurate with the small pressure difference. This corresponds to a case where only a small force exists between two structural elements connected by means of a hydraulic damper fitted with the corresponding valve according to the invention. In the event that a correspondingly larger force exists, i.e. a large difference in pressure between the two sides of the valve, a large displacement may, for instance, be created in the valve, to thereby create a larger cross-section of the through-flow path and enable the valve to create a damping effect commensurate with the larger force. The valve according to the invention thereby overcomes the disadvantage of conventional valves that damping is possible only abruptly after a force exceeds a minimum amount, i.e. after the difference in pressures on the first and second side of the valve exceeds a lower limit, and that the valve will allow damping only within a small functional range of forces between two structural elements that are damped using conventional hydraulic dampers. The valve according to the invention also offers the advantage that the cross-section of the through-flow path is adjustable independently from the design of the load side of the moving element.
[0026] In the valve according to the invention, this will allow easy constructional realisation of a relationship between the pressure on the first side and the through-flow path cross-section, since the restoring force of the spring system, the area of the load side of the moving element and the cross-section of the passages are each constructionally adjustable independently from each other.
[0027] The ability to adjust the cross-section of the through-flow path via the excursion of the valve is an essential characteristic of the valve according to the invention. This is not possible in conventional valves. This adjustability may be realised in different ways according to the invention. A plurality of passages may, for instance, be arranged mutually displaced along the displacement path to thereby increase the cross-section of the through-flow path as the moving element is displaced along the displacement path and an increasing number of passages contribute to the through-flow path. The passages may, for instance, also be constructed to extend over a considerable distance of the displacement path. It may in this case, for instance, be possible for the opening of the valve by displacement of the moving element to increase the proportion of the cross-sectional area of a passage contributing to the through-flow path. Passages with different cross-sections may, for instance, be arranged along the displacement path, wherein increasing excursion of the valve will increase the cross-section of passages through which the through-flow path runs. The valve according to the invention will in any event be designed to render the cross-section of the through-flow path adjustable over a considerable distance of the displacement path and increasing as the deflection from rest position increases, to ensure that a valve according to the invention will ensure damping over a large functional range when fitted in a hydraulic damper.
[0028] The components of a valve according to the invention may, for instance, be designed for the cross-section of the through-flow path over a displacement path exceeding 0.2 mm, in particular between 0.2 mm to 2 mm and in particular 0.2 mm to 10 mm, to increase as the valve excursion increases. The valve may in particular be designed for the cross-section of the through-flow path to increase as the valve excursion increases only over a defined range, wherein the excursion range corresponds to a section of the displacement path with reference to the displacement of the moving element. The cross-section of the through-flow path may, in particular for excursions halfway through the excursion range, also amount to less than half, in particular also less than one third of the maximum cross-section of the through-flow path for excursion of the valve to the maximum of the excursion range.
[0029] The cylinder section of the valve element with the passages will be designed in the form of a cylinder. The passages may pass through the cylinder shell of the cylinder section. The cylinder section may, for instance, be designed as a cylinder with polygonal cross-section. Designing a cylinder section as a cylinder with a round cross-section may be particularly advantageous in ensuring relative and guided movement of the two valve elements. Passages passing through the cylinder shell of the cylinder section will result in an adjustable cross-section of the through-flow path along a displacement path, wherein the displacement path may in particular run parallel to the cylinder axis of the cylinder section. The cylinder section may, in one embodiment of the invention, be designed to deviate from the ideal cylindrical shape by having a frustoconical shape to potentially improve the adjustability of the cross-section of the through-flow path following excursions of the valve.
[0030] Designing the cylinder section as a straight cylinder may be particularly advantageous towards particularly good guidance between the two valve elements. It may in particular be advantageous for the cylinder section of the valve element with the passages to be a hollow cylinder. The through-flow path may then run through the inside of the hollow cylinder, through passages in the cylinder shell and through a channel connecting to the outside of the hollow cylinder.
[0031] The cylinder section of the first valve element and the closed cylinder shell section of the other valve element may be arranged relative to each other such that one of the sections is a hollow cylinder within which at least parts of the other section will fit to ensure guided relative movement of the two valve elements along a displacement path lying parallel to the also parallel cylinder axes of the two sections. One of the sections may, for instance, be a hollow cylinder and the other a solid cylinder, wherein the passages are found in one of the sections. Both sections may, for instance, be designed as hollow cylinder types. The sections may, for instance, be designed to fit into each other with enough play to allow hydraulic fluid to enter the space between sections to reduce friction. Enough play may be provided to allow small amounts of hydraulic fluid to pass from the first to the second side of the valve between the sections, when hydraulic fluid applies pressure to the valve on its first side.
[0032] The two valve elements may in particular also be designed to fit into each other without the requirement of a seal. This implies that perfect sealing between the two sides of the valve will not be assured for any relative position of the two valve elements and hydraulic fluid will always be able to pass through the valve from one side to the other. Fitment without a seal may ensure that a hydraulic damper containing a seal as described can dynamically absorb small forces and thereby avoid tension caused by, for instance, different thermal expansion, between structural elements separated by hydraulic dampers.
[0033] This type of flow of hydraulic fluid, enabled by the play between the two valve elements, may, for instance, be allowed also in rest position. The cross-section of a path allowing a hydraulic fluid to flow from one side of the valve to the other, passing between valve elements in rest position, will in any event amount to only a fraction of the maximum cross-section of the through-flow path during a corresponding excursion of the valve; such a cross-section will in particular amount to less than 1% of the maximum possible cross-section of the through-flow path.
[0034] A section of the other valve element may, for instance, be designed as a hollow cylinder constituting the closed cylinder shell section, wherein in particular a cylinder shell section with passage openings may be present, spaced axially from the closed cylinder shell section. The reference here is the axis of the cylinder that in sections includes the closed cylinder shell section.
[0035] The closed cylinder shell section may in rest position abut one valve element and may in particular also abut the valve element for each excursion of the valve. The design of the cylinder shell section as a hollow cylinder refers to a design of the closed cylinder shell section ensuring that it will form a guide for an axially moveable internal cylinder. The passages may in rest position be located in the closed cylinder shell section or axially adjacent to the closed cylinder shell section, towards one of the two sides of the valve. For a certain excursion of the valve from rest position by relative displacement of the valve elements along the path of displacement that runs axially in relation to the axis of the closed cylinder shell section, the cylinder section of the valve element with the passages will be displaced relative to the closed cylinder shell section of the other valve in such a way that a certain number of passages will at least in part come to lie axially adjacent to the closed cylinder section. The ability of adjusting the cross-section of the through-flow path may be improved by providing passage openings in a cylinder shell section axially aligned with the closed cylinder shell section. This will allow limitation of the cross-section of the through-flow path via both the cross-section of the passages and the cross-section of the passage openings. The through-flow path, at least for certain excursion of the valve, will then in particular include both the passage openings and the passages themselves. Starting from rest position, where the fluid flow between the sides is blocked, excursion of the valve may then be designed to displace the valve elements relative to each other along the displacement path in a way to ensure that at least some of the passages will face at least some of the passage openings.
[0036] The number of passages and passage openings facing each other and the overlapping cross-sections of the passage openings and passages will depend on the excursion. A certain excursion may be designed to create a certain cross-sectional area over which the passage openings and passages overlap. The ability to adjust the cross-section of the through-flow path may be improved by designing the other valve element with two closed cylinder shell sections separated by passage openings in the direction of movement, wherein particularly the one valve element has two zones separated from each other in the direction of movement, each with passages.
[0037] The combined cross-sectional area of the passages through which the through-flow path runs will preferably increase with the excursion of the valve from its rest position through displacement of the moving element along the displacement path. The same may apply to the passage openings. The combined cross-sectional area of the passages through which the through-flow path runs will be given by the sum of the cross-sectional areas of the passages as such. The cross-section of the through-flow path need not here correspond to the combined cross-sectional area, since at least some of the passages used by the through-flow path may be blocked at least partially, for instance by the closed cylinder shell section of the other valve element. The proportion of the cross-sectional area of a passage included in the through-flow path may, in particular, increase as the excursion of the valve increases, since a smaller proportion of the cross-sectional area of this passage will be blocked as the excursion increases. Since the combined cross-sectional area of the passages included in the through-flow path will increase as the valve excursion increases, the cross-section of the through-flow path will also increase as the excursion of the valve increases.
[0038] The valve as fitted in a hydraulic damper will correspondingly ensure that a large force applied to the two sides of a hydraulic damper and consequently a large pressure difference between the two sides of the valve will ensure that large volumes of hydraulic fluid will pass through the valve, in particular via a cross-section of the through-flow path that is larger than when a smaller force is applied. This means that the valve has the flexibility for application across a wide functional range.
[0039] At least some of the passages will preferably be arranged with their centres mutually offset in the direction of movement, wherein, in particular, at least some of the passages will be in the form of elliptical bores. The elliptical bores may, for instance, be substituted by round or oval bores. This will allow the number of passages included in the through-flow path to increase for excursions of the valve from rest position, for instance by ensuring that increasingly large excursions will, in the direction of movement, find an increasing number of passages in the first valve element located adjacent to the closed cylinder section of the second valve element. The passages with mutually offset centres may, for instance, also have different diameters. The mean diameter of passages included in the through-flow path for small excursions may, for instance, be smaller than the mean diameter of passage openings included in the through-flow path when excursions are larger. In the case of increasingly large excursions from rest position for instance, the through-flow path may initially include passages with ca. 2 mm diameter and, in the event of further excursions, add passages with ca. 5 mm diameter.
[0040] The number of passages in the direction of movement may, in particular, vary, where particularly the number of passages may increase in the direction of movement in a way to increase the number of passages included in the through-flow path as the excursion of the valve from rest position increases through displacement of the moving element along the displacement path. This may improve the potential for adjustment of the cross-section of the through-flow path as a function of the excursion.
[0041] Passages that are mutually offset in the direction of movement may, in particular, differ partially at least in their cross-sectional area, particularly in their diameter, wherein particularly the cross-sectional area of passages may increase in the direction of movement in such a manner that the cross-sectional area of passages included in the through-flow path will increase as the excursion of the valve from rest position increases. Mutually offset passages that differ partially at least in their cross-sectional area may ensure that the through-flow path will include passages with different cross-sectional areas, depending on the excursion of the valve, yielding a different cross-section of the through-flow path for each different excursion of the valve. This may further improve the potential for adjusting the cross-section of the through-flow path as a function of the excursion of the valve. By increasing the cross-sectional area of the passages included in the through-flow path as excursions increase, large volumes of hydraulic fluid will be allowed to pass through the valve when excursions are large and therefore when the difference between pressures on the two sides of the valve is large.
[0042] The cross-sectional area of the passages included in the through-flow path may change in a way to increase the mean cross-sectional area of all passages, i.e. the combined cross-sectional area of all passages included in the through-flow path, divided by the number of passages included in this path, as the excursion increases.
[0043] In one embodiment of the valve according to the invention, the valve has a bypass to ensure an uninterrupted connection between its two sides. The bypass may, for instance, be implemented as a bore. The bypass may, for instance, penetrate the moving element, connecting the load side of the moving element to the opposite side of the moving element, opposite the load side. This bypass will ensure compensation of pressures on the two sides of the valve even when the pressure difference is very small. The bypass will allow fluid to flow through a very small cross-sectional area only. The flow cross-section of the bypass may, for instance, allow less than 10%, in particular less than 5%, in particular less than 1% of the maximum cross-section of the through-flow path of the valve.
[0044] The effective area of the moving element via which the effective moving force may be exerted on the moving element when a fluid on the first side applies pressure to the moving element should preferably be less than the cross-section of the cylinder section in which the passages are found. For cases in which one of the valve elements has passages and the other valve element has passage openings, the effective area may be smaller than the cross-section of the specific sections in which the passages or passage openings are found.
[0045] The effective area here designates that area via which the effective displacement force may actually be exerted on the moving element when pressure is exerted on the first side of the valve. If the moving element is designed as a solid cylinder, wherein the load side of the moving element is a circular plane oriented orthogonal to the displacement path of the moving element which runs parallel to the cylinder axis of the moving element, the effective area will, for instance, be equal to the circular area of the load side of the moving element.
[0046] The effective area must in any case be calculated based on the cross-section of the of the moving element on its load side that is orthogonal to the displacement path, since only pressure in the direction of the displacement path will generate effective displacement forces on the moving element. When the moving element is designed as a solid cylinder with an axial bore extending throughout the entire cylinder, wherein a back pressure chamber with a connection to the first side allowing hydraulic fluid to enter when pressure is exerted on the moving element, is provided on the opposing side to the load side of the moving element, the effective area should be calculated as the difference between the cross-sectional area of the moving element on its load side and on its back pressure side, since the force exerted on the moving element from the back pressure side will reduce the effective moving force.
[0047] In a stepped design of the moving element, with the cross-sectional area of the moving element on the load side exceeding that on its opposite side, the effective area will be given by the difference between the cross-sectional areas on the two sides.
[0048] Because the effective area is smaller than the cross-section of the cylinder section in which the passages are found, the large cross-section of the cylinder section will firstly enable the creation of a through-flow path through passages with a large cross-section and secondly reduce the effective displacement force required. This will, for instance, allow the provisioning of a spring system exerting a relatively small restoring force on the moving element, which will be advantageous and allow the manufacture of a fully functional valve according to the invention.
[0049] The diameter of the moving element will preferably change at least by section, in particular through stepping. The diameter of the moving element may in particular reduce in the direction of movement towards the load side. This will, for instance, allow adjustment of the effective area on the load side of the moving element, via which pressure may be exerted on the moving element from the first side, independently of the diameter of the moving element at other positions along the direction of movement. It should in particular be taken into account that the arrangement of the valve with the two valve elements will determine the direction of movement, which may in particular coincide with a cylinder axis of the moving element or run parallel to a cylinder axis that the moving element may have over a section in which it is cylindrical in shape.
[0050] The moving element may in one embodiment of the invention have a fluid passage that has at least one component running parallel to the direction of movement and will create a fluid-carrying connection between the load side and an opposite side of the moving element that lies opposite the load side, wherein the opposite side has a back pressure chamber designed to accept and collect fluid reaching the opposite side via the fluid-carrying connection to ensure that a back pressure will be exerted on the opposite side of the moving element, ensuring that a force opposing the displacement force will be exerted on the moving element. The fluid passage may, for instance, be designed with a cross-section of at least 10%, in particular at least 30%, in particular at least 50% of the maximum cross-section of the through-flow path. A large cross-section of the fluid passage may ensure particularly good functionality of the back pressure chamber. The back pressure chamber may, for instance, be located in the seat element. The back pressure chamber may, for instance, be separated from the second side such that a flow of fluid from the back pressure chamber to the second side will be restricted to the through-flow path, to ensure that first side pressure increasing the pressure in the back pressure chamber cannot immediately be released into the second side. As explained above, a suitable design may ensure that the effective displacement force that a fluid on the first side can exert on the moving element in the valve may be kept relatively low even for great pressures, meaning that, for instance, a spring system with a low spring force may be utilised and yet bring adequate restoring force to bear on the moving element to retain the moving element in its rest position when the pressure on the first side is low, but allow only slow movement along the displacement path when the pressure on the first side increases.
[0051] It should generally be taken into account that the valve according to the invention is designed to block the flow of fluid when the restoring force exceeds the displacement force, whereas the valve has a through-flow path when the displacement force exceeds the restoring force by a sufficient amount, wherein the excursion of the valve and thereby the displacement of the moving element from rest position along the displacement path will increase as the displacement force increases.
[0052] In one embodiment of the invention, the spring system comprises a spring element and a support element, wherein the support element is connected to the seat element. The support element may, for instance, comprise an integral part of the seat element or a separate component connected to the seat element in a valve ready for use. The support element may comprise a passage to allow through-flow of fluid. The connection may, for instance, be screwed on or press fitted. The support element will ensure that the spring force acts between the seat element and the moving element. This will allow particularly effective restorative action when pressure applied to the moving element on its load side causes a displacement of the moving element relative to the seat element. The spring system will furthermore preferably comprise an adjustment device to pretension the spring element between the support element and the moving element, to set the restoring force the spring system will exert on the moving element in rest position. The minimum displacement force required to displace the valve from its rest position may accordingly be set via the adjustment device.
[0053] A displacement force required to open a through-flow path in the valve may correspondingly be set by means of the adjustment device. A specific displacement force required to provide a through-flow path in a valve with a specific cross-section of the through-flow path may accordingly be set. In a valve according to the invention comprising the above embodiment, an adjustable pressure difference required between the sub-chambers of the hydraulic damper for the valve to open a through-flow path with a specific cross-section may accordingly be defined.
[0054] The valve according to the invention will preferably have a damping facility comprising at least one damping chamber located between the seat element and the moving element, with the volume of said chamber depending on the position of the moving element along the displacement path, wherein the damping facility comprises a damping bypass designed to connect the damping chamber with the first and/or second sub-chamber. The volume of the damping chamber may, for instance, be negligibly small when the valve, and thus the moving element, are in rest position. Accordingly, a connection between the damping chamber, which does not exist in rest position and a sub-chamber via a damping bypass will then also not be possible. The damping bypass may be located in the seat element or the moving element in a way to ensure a connection between the damping chamber and at least one of the sub-chambers whenever the moving element is displaced from its rest position and a damping chamber exists. The bypass may, for instance, be located in the seat element, for example in the moving element The damping bypass may, for instance, be constructed as a channel bypass, such as a bore, for instance as a channel bypass in the moving element and/or in the seat element.
[0055] The damping bypass may, for instance, be created in the form of play between the two valve elements, in particular in the form of a loose fit between the valve elements. The cylinder section of the first valve element may, for instance, be constructed to loosely fit the closed cylinder shell section of the other valve element.
[0056] A connection via the bypass between the damping chamber and at least one of the sub-chambers may be ensured if the bypass opens out into at least one side of the valve such that a connection is created between the specific sub-chamber and the damping chamber in a valve connected to a first sub-chamber on its first side and a second sub-chamber on its second side, for instance a valve according to the invention as described above, utilised in a hydraulic damper. The damping bypass may, for instance, run through the seat element and open out into one of the two sides of the valve; the damping channel may, for instance, be located in the moving element and open out into the other side of the valve. Two damping bypasses may, for instance, be provided with both, for example, opening out into the same side or each into a different side of the valve.
[0057] Improved damping of a hydraulic damper with a valve according to the invention may be achieved by judicious arrangement of damping chamber and damping bypass. The damping chamber and damping bypass may retard displacement of the moving element from its rest position when pressure is exerted on the valve from its first side, since the damping bypass will allow only a slight flow of fluid into the damping chamber and since, firstly, a change of damping chamber volume is required for an excursion and, secondly, volume change will require a flow of fluid through the damping bypass.
[0058] This may, for example, where a hydraulic damper comprising a valve according to the invention is fitted between structural elements, counteract jerky relative movement of said elements. A relevant hydraulic damper may furthermore be ideally suited for damping vibrations between structural elements.
[0059] The moving element and the seat element will preferably each have a design stepped down in the direction of movement, wherein the damping chamber will be located between the two stepped valve elements defining the stepped shape. This will enable very easy and effective realisation of a damping chamber in the valve according to the invention, with the chamber volume a function of the excursion from rest position of the moving element along the displacement path.
[0060] The invention furthermore relates to a hydraulic damper for damping of vibrations in structures. As explained for conventional hydraulic dampers, a hydraulic damper the invention relates to will be suited to damp forces between two structural elements separated by the hydraulic damper. The hydraulic damper according to the invention comprises a working chamber with a hydraulic fluid, containing a movable piston that divides the working chamber into two sub-chambers, viz. a first and a second sub-chamber. The hydraulic damper comprises at least one valve to alternately allow and block a flow of fluid between the sub-chambers, to ensure compensation of pressures in the sub-chambers. The hydraulic damper will preferably comprise at least two valves, wherein a first valve will be constructed to permit or block a flow of fluid from the first sub-chamber to the second sub-chamber and a second valve will permit or block a flow of fluid from the second sub-chamber to the first sub-chamber, wherein each of the two valves will allow flow of fluid between the sub-chambers in only one direction and consistently block flow in the opposite direction. The valve may, for instance, be located in the piston. The valve may, however, also be located for instance in a side wall of the working chamber or in the piston rod. The valve may also, for instance, be located in an external valve chamber connecting the two sub-chambers, external to the working chamber. The hydraulic damper may, for instance, be constructed such that the working chamber is connected to a first structural element and the piston to a second structural element to damp forces between the two structural elements. In the presence of a relevant force between the structural elements, the hydraulic damper will dampen the force by moving the piston in the working chamber along its path, thereby changing the ratio of fluid volumes in the sub-chambers. The piston may, for instance, have a chamber bypass connecting the sub-chambers to at all times allow a flow of fluid between the two sub-chambers, across a small cross-section. The valve may, for instance, be constructed to allow a flow of fluid only when the difference between pressures in the two sub-chambers exceeds a lower limit. The hydraulic damper may, for instance, have a valve according to the invention.
[0061] In an embodiment of the invention, the hydraulic damper according to the invention comprises a piston rod attached to the piston, wherein the piston rod extends axially through the working chamber and will in all positions extend beyond the working chamber into a compensation chamber located axially in line behind the working chamber and will be connected to the working chamber via a channel.
[0062] At least one bounding wall of the compensation chamber is constructed as a separation element separating the compensation chamber from a gas pressure chamber located against the compensation chamber, wherein the separation element will be designed to ensure variation of the ratio of compensation chamber volumes and gas pressure chamber volumes. The axial extension of the piston rod will simultaneously determine the direction in which the compensation chamber will be located adjacent to the working chamber. The channel between compensation chamber and working chamber may, for instance, function as a bypass with a small flow cross-section and the channel may, for example, also include a valve. Since the gas pressure chamber is separated from the compensation chamber by a separation element designed to ensure variation of the ratio of compensation chamber and gas pressure chamber volumes, the volume of the gas pressure chamber may be reduced if the volume of hydraulic fluid or of the piston rod in the compensation chamber is increased. The separation element may to this end, for instance, be designed to be movable. The compensation chamber may, for instance, be designed as a hollow cylinder or have a prolongation towards the gas pressure chamber in the form of a hollow cylinder, wherein the separation element may be located movable in the relevant hollow cylinder to allow corresponding variation of volume ratios. The separation element may, for instance, be elastic, for instance in the form of an elastic membrane fitted between the compensation and gas pressure chambers, to ensure or support volume ratio change.
[0063] It may be ensured by arranging the compensation chamber and working chamber axially in sequence, that every movement of the piston rod and thus every movement of its solidly attached piston will directly change the piston rod volume located in the compensation chamber. The piston rod may here be arranged in the compensation chamber in such a way that it will be immersed the hydraulic fluid. The piston rod in the compensation chamber may in any case be arranged such that the change of piston rod volume in the compensation chamber will, given theoretically assumed constant hydraulic fluid volume in the compensation chamber, will directly increase the compensation chamber pressure. This will allow movement of the piston rod as such to bring about displacements of the separation element, independent of whether displacement of the piston rod and simultaneous displacement of the piston will simultaneously also change the volume of fluid in the compensation chamber.
[0064] The described embodiment of the hydraulic damper according to the invention will have significant advantages. Pressure change in the working chamber caused by the expansion of hydraulic fluid in the working chamber at increased temperatures may be effectively counteracted by means of a compensation chamber. The increase of pressure in the working chamber with rising temperature may be buffered by the compressible gas in a gas pressure chamber separated from the compensation chamber by a separation element.
[0065] By positioning the gas pressure chamber adjacent to the compensation chamber and outside the working chamber, easy access to the gas pressure chamber from the outside may furthermore be ensured, thereby allowing monitoring of the pressure in the gas pressure chamber and adjustment of the pressure or the exchange of gas, as needed. The design of the embodiment according to the invention will furthermore ensure that a restoring force will act on the hydraulic damper when it changes from its stationary position, tending to return the damper to its stationary position. Contributing to this in particular is the circumstance that a displacement of the piston rod will directly change the piston rod volume in the compensation chamber and thus directly change the pressure in the gas pressure chamber. The gas in the gas pressure chamber will therefore exert a corresponding restoring force on the hydraulic damper. The restoring force is thus generated not only by changes in the volume of hydraulic fluid in the compensation chamber but also by a change in the piston rod volume in the compensation chamber.
[0066] The gas pressure chamber will preferentially be located axially in line behind the compensation chamber, wherein the piston rod in particular will extend at least into a range of positions in the gas pressure chamber. The piston rod may, for instance, extend into the gas pressure chamber from any arbitrary position of the piston along its path inside the working chamber. The hydraulic damper may, however, also be designed such that the piston rod will, from some positions of the piston along the piston path, extend only into the working chamber and compensation chamber, but will extend into the gas pressure chamber as well from other positions of the piston along the piston path.
[0067] The embodiment according to the invention can ensure that a change in the position of the piston rod will directly change the piston rod volume in the gas pressure chamber, at least over a range of positions of the piston rod or piston, with the result that a displacement of the piston rod as such can affect the restoring force acting on the hydraulic damper.
[0068] In an embodiment of the invention, the piston rod will be arranged in the hydraulic damper such that any change in the position of the piston rod will change the volume of the piston rod located inside the gas pressure chamber or the compensation chamber, wherein any change to this piston rod volume will directly contribute to a change in the ratio of pressures in the compensation chamber and the gas pressure chamber. The piston rod may, for instance, be arranged in the hydraulic damper such that it will always extend fully through the compensation chamber and into the gas pressure chamber from a range of positions of the piston along the piston path, with the result that a change in position of the piston rod within this range will not directly change the piston rod volume in the compensation chamber, but will change the piston rod volume in the gas pressure chamber. The piston rod may, for instance, be arranged in the hydraulic damper in such a way that the piston rod will, over a range of positions, extend into the working chamber such that any change in position of the piston rod within this range of positions will directly change the piston rod volume in the working chamber, whilst the piston rod volume in the gas pressure chamber will not change as the position of the piston rod changes within this range.
[0069] The embodiment according to the invention will reliably ensure that position changes of the piston rod will contribute to the generation of a restoring force in the hydraulic damper.
BRIEF DESCRIPTION OF THE DRAWINGS
[0070] The invention is explained in detail below, based on exemplary embodiments of the invention illustrated by means of six Figures. The figures show:
[0071] FIG. 1 a is a schematic sectional view of a first embodiment of the valve according to the invention;
[0072] FIG. 1 b is a schematic sectional view of a variation on the first embodiment;
[0073] FIG. 2 is a schematic sectional view of a second embodiment of the valve according to the invention;
[0074] FIG. 3 a is a schematic sectional view of a third embodiment of the valve according to the invention;
[0075] FIG. 3 b is a schematic sectional view of a section of a variation on the third embodiment of the valve according to the invention;
[0076] FIG. 4 is a schematic sectional view of a fourth embodiment of the valve according to the invention;
[0077] FIG. 5 is a schematic sectional view of a fifth embodiment of the valve according to the invention; and
[0078] FIG. 6 is a schematic sectional view of an embodiment of the hydraulic damper according to the invention.
DETAILED DESCRIPTION
[0079] FIG. 1 a illustrates an embodiment of valve 1 according to the invention by way of a schematic cross-section. FIG. 1 a shows valve 1 in its rest position. Valve 1 comprises a seat element 3 and a moving element 4 . Seat element 3 has a cylindrical section in the form of a hollow cylinder with a closed cylindrical shell section 7 . This cylindrical section of seat element 3 holds a section of moving element 4 , which is also constructed as a hollow cylinder featuring passages 6 in its cylinder shell. The hollow cylinder section of moving element 4 fits loosely into the aforementioned hollow cylinder section of seat element 3 . Moving element 4 and seat element 3 are mutually guided over the two sections, whereby the play between moving element 4 and seat element 3 is sufficient to allow small quantities of hydraulic fluid to penetrate between moving element 4 and seat element 3 , thereby lubricating between the elements.
[0080] FIG. 1 a shows that the diameter of moving element 4 , which in some embodiments and also in the embodiment shown in FIG. 1 a , may be taken as equivalent to the cross-section of moving element 4 orthogonal to the direction of movement, changes in steps. From the step on its load side to its opposite side, the cross-section of moving element 4 actually increases in steps. Since seat element 3 has a matching stepped design, it has an end stop 31 against which moving element 4 will rest when in rest position. The matching stepped design of seat element 3 and moving element 4 , creating an end stop 31 against which moving element 4 will come to rest against seat element 3 , may have general advantages to valves according to the invention.
[0081] In rest position, spring system 5 will press moving element 4 against the end stop of seat elements 3 . Spring system 5 comprises spring element 51 and support element 52 and an adjustment device 53 . Adjustment device 53 is designed as a thread between support element 52 and seat element 3 . This will allow the spring force which spring system 5 will exert on moving element 4 to be set via adjustment device 53 . Spring element 51 will always be connected to seat element 3 via support element 52 . The restoring force exerted by spring system 5 on moving element 4 in rest position and when deflected from rest position is adjustable via the spring tension.
[0082] In rest position as illustrated, passages 6 of moving element 4 will be opposite closed cylinder shell section 7 of seat element 3 , with the effect that valve 1 has no through-flow path in this position. The closed cylinder shell section 7 will effectively prevent through-flow from first side 100 to second side 200 through passages 6 . Valve 1 , however, has a bypass 8 that permanently interconnects sides 100 and 200 of valve 1 , allowing a slight difference in pressure that may arise on sides 100 and 200 to be compensated via bypass 8 .
[0083] When pressure in excess of the pressure in rest position is exerted on valve 1 from its first side 100 , moving element 4 will, on its load side facing first side 100 , experience a displacement force towards the second side 200 .
[0084] As soon as the displacement force exceeds the restoring force, valve 1 and thus moving element 4 will be deflected from its rest position, wherein moving element 4 will move in the direction of movement x which, in the illustrated embodiment of the invention, coincides with the axis of the cylinder section designed as a hollow cylinder with passages 6 of the moving element 4 and with the axis of the cylinder section designed as a hollow cylinder with closed cylinder shell section 7 of seat element 3 . As soon as moving element 4 is displaced from its rest position to the extent that at least one of the passages 6 in the direction of movement x is positioned adjacent to closed cylinder shell section 7 , valve 1 will have a through-flow path running through the relevant passage or passages 6 , with its through-flow cross-section restricted by the cross-section of the relevant passages 6 and, depending on the displacement of moving element 4 and possibly also by the closed cylinder shell section 7 which, depending on the excursion of valve 1 from its rest position, may cover part of the cross-section of at least one of the passages 6 .
[0085] As shown in FIG. 1 , valve 1 according to the invention has several passages 6 , with different cross-sections and with their centres offset from each other in the direction of movement x. The through-flow cross-section of the through-flow path will therefore change, depending on how far valve 1 and thus moving element 4 are displaced from rest position. The through-flow cross-section of the through-flow path is thereby adjustable via the excursion of valve 1 from rest position.
[0086] FIG. 1 b schematically illustrates a cross-section of an embodiment of valve 1 according to the invention, analogous to FIG. 1 a.
[0087] The embodiment shown in FIG. 1 b essentially corresponds to the embodiment shown in FIG. 1 a wherein, however, the embodiment shown in FIG. 1 b has been altered a way to include sealing element 14 , a damping chamber 12 and a damping bypass 13 . Furthermore, the effective area via which pressure by a fluid on the first side 100 will exert a force on the load side of moving element 4 , is different from the embodiment shown in FIG. 1 a.
[0088] The sealing element 14 is embraced by seat element 3 , wherein seat element 3 and sealing element 14 constitute an inherently stable unit. Seat element 3 thereby has a stepped design that matches a correspondingly stepped form created by the stepped design of moving element 4 . Damping chamber 12 is located between the steps of moving element 4 and seat element 3 . Damping chamber 12 has a hydraulic connection to the first side 100 via damping bypass 13 , thus permanently connecting damping chamber 12 with the first sub-chamber when valve 1 is connected to a first sub-chamber on its first side 100 . When moving element 4 is displaced from its rest position shown in FIG. 1 b , a fluid from the first side 100 will reach damping chamber 12 via damping bypass 13 . A displacement of moving element 4 from its rest position is largely prevented unless fluid can reach damping chamber 12 . The small damping bypass 13 connecting damping chamber 12 and first side 100 will ensure additional damping of valve 1 , which may be beneficial especially when deploying valve 1 in a hydraulic damper according to the invention. It is evident from FIG. 1 b that the volume of damping chamber 12 will depend on the position of moving element 4 along the displacement path in the direction of movement x.
[0089] FIG. 1 b furthermore shows that diameter d 2 of the cylinder section of moving element 4 containing passages 6 , is significantly greater than diameter d 1 which determines the effective area over which moving element 4 will be subjected on its load side to pressure by a fluid on first side 100 , thereby to exert a displacement force on moving element 4 . As per the embodiment shown in FIG. 1 b , valve 1 is correspondingly designed such that the effective displacement force exerted by pressure on first side 100 on moving element 4 may be relatively small for a certain first side 100 pressure on valve 1 , whilst the through-flow cross-section through arrangement of passages 6 in a cylinder section with a large diameter d 2 may be correspondingly large for a relevant excursion of valve 1 from its rest position.
[0090] FIG. 2 schematically shows a further embodiment of valve 1 according to the invention. Valve 1 comprises a seat element 3 with a hollow cylindrical section that contains passages 6 in its cylinder shell. In the rest position of valve 1 shown in FIG. 2 , valve 1 has no through-flow path, since it is designed to block the flow of fluid between the two sides 100 , 200 . In rest position, a closed cylinder shell section 7 containing moving element 4 is to this end positioned opposite passages 6 . The closed cylinder shell section 7 is not, however, in close contact with the edge of passages 6 in rest position, since both seat element 3 and moving element 4 are stepped, thereby reducing the diameter along the direction of movement x of moving element 4 from diameter d 2 to diameter d 3 and correspondingly reducing the inside diameter of the hollow cylindrical seat element 3 from d 2 to d 3 .
[0091] Spring system 5 is designed analogous to spring systems 5 of the embodiments shown in FIGS. 1 a and 1 b and correspondingly features a spring element 51 , a support element 52 and an adjustment device 53 . Spring system 5 will in rest position press moving element 4 against the ring-shaped end stop 31 which is embraced by seat element 3 . When pressure is exerted on moving element 4 from the first side 100 in a way to exert an effective displacement force on moving element 4 that exceeds the restoring force the spring system 5 is exerting on moving element 4 , valve 1 and thereby moving element 4 will be displaced from rest position, effectively displacing moving element 4 from rest position in the direction of movement x. As soon as passages 6 are positioned at least partially adjacent to closed cylinder shell section 7 of moving element 4 when moving element 4 is displaced in the direction of movement x, valve 1 will have a through-flow path with a cross-section that will increase as the excursion in the direction of movement x increases, until the closed cylinder shell section 7 fully exposes all the passages 6 . In the embodiment of the invention shown in FIG. 2 , support element 52 has a bypass 8 via which sides 100 and 200 of valve 1 will be permanently hydraulically connected.
[0092] Moving element 4 furthermore comprises a fluid channel 10 connecting the load side of moving element 4 to the opposite side of moving element 4 . Seat element 3 comprises a back pressure chamber 11 on the opposite side of moving element 4 .
[0093] When pressure is brought to bear on valve 1 from its first side 100 , fluid will pass through fluid channel 10 to the back pressure chamber 11 , to there exert a force against direction of movement x on moving element 4 . The effective area via which a fluid on the first side 100 will thus exert pressure on moving element 4 to thereby create a displacement force on moving element 4 in the direction of movement x, may thus be calculated based on the difference of the cross-sections defined by diameters d 2 and d 3 . The displacement force may thus be kept low in this way, even should the first side 100 exert high pressures valve 1 , thus allowing the use of simple and low-cost spring systems 5 in valve 1 in the illustrated embodiment according to the invention.
[0094] FIG. 3 a schematically depicts a variation on the embodiment illustrated in FIG. 2 .
[0095] The embodiment illustrated in FIG. 3 a differs from that in FIG. 2 mainly in terms of the moving element 4 exhibiting a cylinder section with passages 6 , wherein seat element 3 provides passage openings 9 . In the rest position shown in FIG. 3 , valve 1 will block the flow of fluid between the two sides 100 , 200 of valve 1 . Bypass 8 will allow only a small fraction of fluid to flow between the two sides 100 , 200 . When valve 1 is displaced from rest position, thereby also displacing element 4 away from its rest position against stop 31 , a through-flow path will open in valve 1 as soon as the cross-sectional areas of at least some of the passages 6 overlap with the cross-sectional areas of at least some of the passage openings 9 . As explained already, the provision of passage openings 9 and passages 6 will allow particularly good adjustment of the passage cross-section as a function of the excursion of valve 1 .
[0096] The fact that, in the example of the embodiment of the invention shown in FIG. 3 a , the centres of passages 6 are offset to each other in the direction of movement x, partially at least, is another factor contributing to the good adjustability of the cross section of the through-flow path.
[0097] The number of passages 6 whose cross-section may be positioned opposite the cross-section of passage openings 9 , is thus variable as a function of the displacement of moving element 4 . This also means that the joint cross-sectional area of passages 6 included in the through-flow path may be increased as the excursion from rest position increases.
[0098] FIG. 3 b shows a section of an example of an embodiment of a valve 1 according to the invention, corresponding to a variation on valve 1 as shown in FIG. 3 a . As opposed to the valve 1 shown in FIG. 3 a , the valve 1 shown in FIG. 3 b has a damping chamber 12 and a further damping chamber 121 , each with a hydraulic connection to the first side 100 of valve 1 via a damping bypass 13 , 131 . Damping chambers 12 , 121 are created by means of corresponding steps provided in seat element 3 and moving element 4 . FIG. 3 b shows that the volume of damping chambers 12 , 121 will change as the moving element 4 is displaced in the direction of movement x. Starting from rest position as shown in FIG. 3 b , the volume of damping chamber 12 will increase with increasing excursions, whilst the volume of damping chamber 121 will decrease with increasing excursions. Both damping chambers 12 , 121 and their assigned damping bypasses 13 , 131 will in any case increase the damping in valve 1 shown in FIG. 3 b , since bypasses 13 , 131 will limit the flow of fluid into and out of damping chambers 12 , 121 , thereby damping displacements of moving element 4 relative to seat element 3 and the required change in volume of damping chambers 12 , 121 and the commensurate flow of fluid through damping bypasses 13 , 131 .
[0099] FIG. 4 shows another example of an embodiment of a valve 1 according to the invention. The example of an embodiment as shown in FIG. 4 also has a moving element 4 and a seat element 3 , with also a spring system 5 comprising spring element 51 , support element 52 and adjustment device 53 . Seat element 4 has a bypass 8 connecting the load side with the opposite side of moving element 4 , thereby allowing a small flow of fluid between sides 100 , 200 of valve 1 even at very slight pressure difference between sides 100 , 200 . Moving element 4 has a diameter d 1 at its load side, creating an effective area over which fluid at the first side 100 will exert pressure on the load side of moving element 4 . Moving element 4 furthermore has a cylinder section designed as a hollow cylinder. This cylinder section also comprises passages 6 in the cylinder shell. This cylinder section has a diameter d 2 which is significantly larger than diameter d 1 of moving element 4 at its load side. The difference between diameters d 1 and d 2 of moving element 4 is realised through the stepped design of moving element 4 . The stepped design thus allows the force exerted on moving element 4 to be kept relatively low due to the small effective area on the load side, even should the first side 100 exert large pressures on moving element 4 , whereas a large cross-section of the through-flow path through passages 6 for a specific excursion of valve 1 may be ensured by providing passages 6 on a cylinder section with a large diameter d 2 . In the rest position shown in FIG. 4 , spring system 5 presses moving element 4 against end stop 31 of seat element 3 . Moving element 4 will be displaced from its rest position when a displacement force acts on the load side of moving element 4 that exceeds the restoring force spring system 5 exerts on moving element 4 against direction of movement x.
[0100] As soon as moving element 4 is displaced from its rest position in direction of movement x such that the closed cylinder shell section 7 is positioned next to passages 6 , with the cross-section of at least some of the passages 6 overlapping the cross-section of passage openings 9 that are arranged in a cylinder shell section of seat element 3 , a through-flow path will open in valve 1 , allowing fluid to pass from the first side 100 to the second side 200 .
[0101] FIG. 4 furthermore shows that moving element 4 includes another cylinder section with more passages 6 . Via the excursion of moving element 4 from rest position along its displacement path, the flow of fluid through the through-flow path may, with increasing excursion, be increased by moving additional passages 6 closer to the second side 200 , thereby reducing the resistance in the through-flow path. This is because another closed cylinder section of seat element 3 will be positioned opposite the further passages 6 , thereby shortening the path a fluid flowing along the further closed cylinder section must take from the first side 100 to reach the second side 200 , as moving element 4 moves from its rest position. The further passages 6 will moreover ensure that fluid entering the hollow cylinder section of moving element 4 from the first sub-chamber 100 via passages 6 , will be able to exit this section of moving element 4 to enter the second sub-chamber 200 via a large through-flow cross-section, thereby ensuring that the flow of fluid from first sub-chamber 100 to second sub-chamber 200 will be throttled exclusively through the combinations passage openings 9 and passages 6 that regulate fluid inflow from the first sub-chamber 100 to moving element 4 .
[0102] The valve 1 according to the invention, shown in FIG. 4 , furthermore comprises a damping chamber 12 and a damping bypass 13 . Valve elements 3 , 4 are each stepped, thus exhibiting a shape stepped down in the direction of movement. The space between steps creates the damping chamber 12 . The volume of damping chamber 12 thus varies as the position of moving element 4 varies along the displacement path. Damping bypass 13 is constructed as a bore in moving element 4 , connecting the second sub-chamber 200 with damping chamber 12 . Since damping chamber 12 hydraulically communicates with its environment exclusively via damping bypass 13 , a flow of fluid through damping bypass 13 will be required to vary the volume of damping chamber 12 . The small cross-section of damping bypass 13 will therefore further enhance the damping performance of valve 1 .
[0103] FIG. 5 schematically illustrates a further embodiment of valve 1 according to the invention. Valve 1 embraces a seat element 3 and a moving element 4 , each stepped in the direction of movement x. The design stepped in the direction of movement x generally refers to one of the valve elements 3 , 4 having a first cross-section at a first position, which will then change stepped in the direction of movement x for the valve element to exhibit a second cross-section at a second position. The other valve element, provided it is shaped to match the stepped shape of the first valve element, will exhibit a recess with a cross-section matching the first cross-section of the first valve element, wherein the other valve element, at a further position spaced in the direction of movement x from the first position, will exhibit a recess with a second cross-section corresponding to the second cross-section of the first valve element.
[0104] In the present case, seat element 3 comprises a first cylinder section with a cross-section defined by diameter d 1 and, offset in the direction of movement x, a second cylinder section with a cross-section defined by diameter d 2 , wherein diameter d 2 is significantly larger than diameter d 1 . Moving element 4 is designed as a correspondingly hollow cylinder, with a first and a second section with inside diameters essentially matching diameters d 1 and d 2 , thus guiding moving element 4 along seat element 3 .
[0105] Seat element 3 comprises passages 6 in the second cylinder section. In rest position, passages 6 will be opposite a closed cylinder shell section 7 of the second cylinder section of moving element 4 . In rest position as shown in FIG. 5 , spring system 5 will press moving element 4 against end stop 31 of seat element 3 . With an excursion of valve 1 from its rest position, moving element 4 will be displaced from its rest position in the direction of movement x along the displacement path, allowing passages 6 to be positioned at least partially adjacent to closed cylinder shell section 7 in the direction of movement x. At a specific excursion of valve 1 from its rest position, valve 1 will correspondingly open a through-flow path including at least some of the passages 6 .
[0106] The stepped designs of seat element 3 and moving element 4 furthermore ensures that passages 6 may be arranged in a cylinder shell section 7 with a large diameter, whereas the effective area over which moving element 4 may experience a first side 100 fluid pressure on its load side is simultaneously kept small, allowing the demands made on spring system 5 in respect of the required restoring force which said system must exert on moving element 4 to adequately damp valve 1 may be kept relatively modest.
[0107] The example of an embodiment of valve 1 according to the invention illustrated in FIG. 5 shows a damping chamber 12 with a permanent hydraulic connection to the second side 200 via damping channel 13 . Damping chamber 12 is created by the stepped design of seat element 3 and moving element 4 . The volume of damping chamber 12 will correspondingly change proportional to the excursion of valve 1 from rest position.
[0108] FIG. 6 schematically shows a cross-section of an example of an embodiment of a hydraulic damper 2 according to the invention. Hydraulic damper 2 comprises a working chamber divided by piston 23 into a first sub-chamber 21 and a second sub-chamber 22 . Piston 23 is solidly attached to piston rod 24 . This means that any displacement of piston rod 24 will result in a corresponding displacement of piston 23 in the working chamber.
[0109] The ratio of volumes in the two sub-chambers 21 , 22 will change with every displacement of piston 23 along its path in the working chamber. The piston path is the path along which piston 23 is movable in the working chamber in the axial direction of piston rod 24 . Piston 23 comprises two valves 1 that will permit a flow of fluid between the two sub-chambers 21 , 22 only whilst the difference in sub-chambers 21 , 22 pressures exceeds a lower limit. A first valve 1 is designed to allow fluid to flow from the first sub-chamber 21 to the second sub-chamber 22 and will block flow of fluid in the opposite direction; a second valve 1 is designed to allow fluid to flow from the second sub-chamber 22 to the first sub-chamber 21 and to block fluid flow in the opposite direction.
[0110] A first mounting device A is connected to the enclosure of the work chamber, whilst a second mounting device B is connected to the piston rod 24 . To dampen movement due to forces between the two structural elements, hydraulic damper 2 may be fastened to a first structural element by first mounting device A and to a second structural element by second mounting device B. Forces exerted on the two mounting devices A, B, which compress or expand the hydraulic damper 2 , will move piston 23 inside the working chamber. This will compress the fluid inside one of the two sub-chambers 21 , 22 , creating a difference between the pressures in said sub-chambers and opening at least one of the valves 1 to allow a flow of fluid between sub-chambers 21 , 22 . Piston 23 will thus effectively move in the working chamber and change the ratio of volumes in the two sub-chambers 21 , 22 . The movement of piston 23 in the working chamber will dampen the force transmitted to the two mounting devices A, B.
[0111] A compensation chamber 25 is located axially in line behind the working chamber. The axial direction is defined by the direction in which piston rod 24 extends. The compensation chamber 25 is connected to the working chamber via a channel 26 . Channel 26 has a small cross-section to allow only a small flow of fluid to pass between compensation chamber 25 and the working chamber via this channel 26 . Channel 26 connects compensation chamber 25 with the first sub-chamber 21 of the working chamber. A gas pressure chamber 28 , separated from compensation chamber 25 by a separation element 27 , is located axially in line behind compensation chamber 25 .
[0112] The separation element 27 is designed axially displaceable, wherein displacement of the separation element 27 will change the ratio of gas pressure chamber 28 the compensation chamber 25 volumes.
[0113] In the example of an embodiment shown in FIG. 6 , the piston rod 24 will extend along the piston path into compensation chamber 25 for any position of piston 23 . Any displacement of piston 23 along the piston path will thus change the piston rod 24 volume in compensation chamber 25 . Changing the piston rod 24 volume in compensation chamber 25 will always change the ratio of gas pressure chamber 28 volume and compensation chamber 25 volume (provided hydraulic damper 2 is a closed system without external impact, for instance on gas pressure chamber 28 , as is the case here). Displacement of piston 23 in the working chamber in a way to reduce the volume of the first sub-chamber 21 and correspondingly increase the volume of the second sub-chamber 22 will, for instance, directly increase the piston rod 24 volume in compensation chamber 25 , thereby moving separation element 27 to decrease the volume of gas pressure chamber 28 and increase the volume of compensation chamber 25 . This will increase the pressure in gas pressure chamber 28 , creating a restoring force on piston rod 24 . A hydraulic damper 2 according to the invention, with its staggered arrangement of working chamber 24 , compensation chamber 25 and gas pressure chamber 28 , therefore has a very simple design and will at the same time allow a restoring force to be exerted on piston rod 24 and thus piston 23 when the hydraulic damper 2 is displaced from the stationary position in which it was fastened by means of its mounting devices A, B.
[0114] Hydraulic damper 2 according to the invention furthermore provides a nozzle 29 via which gas pressure chamber 28 may be filled with gas or its pressure controlled. Excessive overpressure in gas pressure chamber 28 may, for instance, also be effectively prevented in this way. In the example of an embodiment described, simple provisioning of gas pressure chamber 28 via nozzle 29 is facilitated since gas pressure chamber 28 is located axially in line behind compensation chamber 25 , which in turn is arranged axially in line behind the working chamber.
[0115] The examples of embodiments of the valve according to the invention and of the hydraulic damper according to the invention conclusively demonstrate that the valve according to the invention and the hydraulic damper according to the invention have a simple design and can offer significant advantages over conventional valves or hydraulic dampers. The simple design of the valves according to the invention render these easy and cost-effective to produce, enabling the manufacture of hydraulic dampers to damp forces arising between two structural elements over a large functional range, since the valves can provide a through-flow path of varying cross-section, depending forces exerted on the hydraulic damper, wherein the cross-section of the through-flow path may, for instance, be enlarged for larger forces.
[0116] The hydraulic damper according to the invention will therefore be particularly well suited for damping of vibrations over a large functional range.
[0117] The staggered design of the hydraulic damper according to the invention will furthermore also facilitate maintenance. The hydraulic damper according to the invention furthermore ensures reliable restoring forces to reduce excursions of structural elements between which the hydraulic damper will be mounted to a minimum and to also dampen vibrations in particular.
LIST OF REFERENCE NUMBERS
[0000]
1 Valve
2 Hydraulic damper
3 Seat element
4 Moving element
5 Spring system
6 Passage
7 Closed cylinder shell section
8 Bypass
9 Passage opening
10 Fluid passage
12 121 Damping chamber
131 Damping bypass
14 Sealing element
16 Back pressure chamber
21 First sub-chamber
22 Second sub-chamber
23 Piston
24 Piston rod
25 Compensation chamber
26 Channel
27 Separation element
28 Gas pressure chamber
29 Feed line
31 End stop
51 Spring element
52 Support element
53 Adjustment device
100 First side
200 Second side
A First mounting device
B Second mounting device
d 1 , d 2 , d 3 Diameter
x Direction of movement
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The invention relates to a valve to ensure pressure compensation between subchambers of a hydraulic damper, wherein the valve comprises a first side for connection to a first subchamber and a second side for connection to a second subchamber, the valve is designed to shut off in its rest position a flow of fluid between the two sides and comprises, when deflected from its rest position, a passage channel with a passage cross-section for admitting the flow of fluid, the valve comprises two valve elements guided towards each other and movable towards each other along a path of movement in a movement direction x, one of the two valve elements is designed as a moving element and the other valve element as a seat element, a pressure can be applied to the moving element, on the load side thereof, by a fluid coming from the first side, generating an effective force for moving the moving element in the moving direction x, and the moving element is connected to a spring system which applies to the moving element a spring force, generating a restoring force opposite to the effective moving force. At least one of the valve elements comprises a cylinder section comprising a plurality of passages, the passage channel runs through at least some of the passages and the passage cross-section is limited by a cross-section of these passages, while the other valve element comprises a closed cylindrical surface which lies on the one valve element in the rest position, shutting off the flow of fluid, and the passage cross-section can be adjusted by the deflection of the valve as a result of the movement of the moving element towards the seat element in the direction of movement x, the passage cross-section increasing with the deflection.
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BACKGROUND OF THE INVENTION
[0001] The present inventions are related to systems and methods for performing data calibration in an out of order data processing system.
[0002] Various data transfer systems have been developed including storage systems, cellular telephone systems, and radio transmission systems. In each of the systems data is transferred from a sender to a receiver via some medium. For example, in a storage system, data is sent from a sender (i.e., a write function) to a receiver (i.e., a read function) via a storage medium. The effectiveness of any transfer is impacted by any data losses caused by various factors. In some cases, an encoding/decoding process is used to enhance the ability to detect a data error and to correct such data errors. As an example, a simple data detection and decode may be performed, however, such a simple process often lacks the capability to converge on a corrected data stream.
[0003] To heighten the possibility of convergence, various existing processes utilize two or more detection and decode iterations. Such an approach assures that at least two detection and decoding processes are applied to each presented data set. However, such an approach absolutely requires two iterations for each input data set that is introduced. This may waste significant power and introduce unnecessary latency where the input is capable of converging in a single iteration. Further, in some cases two iterations is insufficient to result in a convergence. Thus, such an approach is both wasteful in some conditions and insufficient in other conditions.
[0004] Hence, for at least the aforementioned reasons, there exists a need in the art for advanced systems and methods for data processing.
BRIEF SUMMARY OF THE INVENTION
[0005] The present inventions are related to systems and methods for performing data calibration in an out of order data processing system.
[0006] Various embodiments of the present invention provide data processing circuits. Such data processing circuits include a first detector circuit, a second detector circuit, and a calibration circuit. The first detector circuit is operable to receive a first data set and to apply a data detection algorithm to the first data set, and the second detector circuit is operable to receive a second data set and to apply the data detection algorithm to the second data set. The calibration circuit is operable to calculate a data detection parameter based upon a third data set. The data detection parameter is used by the first detector circuit in applying the data detection algorithm to the first data set during a period that the data detection parameter is used by the second detector circuit in applying the data detection algorithm to the second data set. In various instances of the aforementioned embodiments, the data processing circuit further includes a decoding circuit that is operable to: receive a first detected output from the first detector circuit, apply a decoding algorithm to the first detected output, and to provide the second data set; and receive a second detected output from the second detector circuit, apply a decoding algorithm to the second detected output, and to provide a fourth data set.
[0007] In some instances of the aforementioned embodiments, the circuit further includes a memory that is operable to store the data detection parameter. In some such cases, the first detector circuit is operable to receive the data detection parameter directly from the calibration circuit, and the second detector circuit is operable to receive the data detection parameter directly from the memory. In one or more cases, the first detector circuit begins processing the first data set before the second detector circuit begins processing the second data set.
[0008] In various instances of the aforementioned embodiments, the first detector circuit applies the detection algorithm to the second data set before the second detector circuit applies the detection algorithm to the second data set. In such cases, the data processing circuit is an out of order data processing circuit that is capable of finishing processing of the first data set before the second data set.
[0009] In one or more embodiments of the present invention, the calibration circuit includes a noise predictive finite impulse response filter. In some instances of the aforementioned embodiments, the calibration circuit adaptively calculates the data detection parameter based upon the third data set and at least one preceding data set. The at least one preceding data set may include the first data set, the second data set, or both the first data set and second data set.
[0010] Other embodiments of the present invention provide methods for updating detector parameters in a data processing circuit. The methods include calculating a data detection parameter based at least in part on a first data set; applying a data detection algorithm using a first data detector circuit to a second data set using the data detection parameter; applying the data detection algorithm using the first data detector circuit to a third data set; and applying the data detection algorithm using a second data detector circuit to the third data set using the data detection parameter during a period that the first data detector circuit applies the data detection algorithm to the second data set. Applying the data detection algorithm to the third data set by the first data detector circuit is done before applying the data detection algorithm to the second data set by the second detector circuit.
[0011] In some instances of the aforementioned embodiments, calculating the data detection parameter is done by a calculation circuit, and the method further includes storing the data detection parameter in a memory. In such cases, the second detector circuit receives the data detection parameter from the memory, and the first detector circuit receives the data detection parameter directly form the calculation circuit. In some cases, the first detector circuit receives the data detection parameter directly from the calibration circuit, and the second detector circuit receives the data detection parameter directly from the memory. In particular cases, the first detector circuit begins applying the data detection algorithm to the second data set before the second detector circuit begins applying the data detection algorithm to the third data set.
[0012] In various instances of the aforementioned embodiments, the methods further include applying a decoding algorithm by a decoder circuit to the third data set after applying the data detection algorithm by the first data detector circuit to the third data set, and before applying the data detection algorithm by the second data detector circuit to the third data set. In some instances of the aforementioned embodiments, the decoding algorithm is a low density parity check decoding algorithm, and the detection algorithm is either a Viterbi algorithm detection algorithm or a maximum a posteriori detector algorithm.
[0013] Yet other embodiments of the present invention provide storage systems that include a storage medium; a read/write head assembly disposed in relation to the storage medium; and a read channel circuit. The storage medium stores a first data set, a second data set and a third data set. The read channel circuit is operable to receive the first data set, the second data set and the third data set via the read/write head assembly. The read channel circuit includes a first detector circuit, a second detector circuit and a calibration circuit. The first detector circuit is operable to receive the first data set and to apply a data detection algorithm to the first data set. The second detector circuit is operable to receive the second data set and to apply the data detection algorithm to the second data set. The calibration circuit is operable to calculate a data detection parameter based upon the third data set. The data detection parameter is used by the first detector circuit in applying the data detection algorithm to the first data set during a period that the data detection parameter is used by the second detector circuit in applying the data detection algorithm to the second data set.
[0014] This summary provides only a general outline of some embodiments of the invention. Many other objects, features, advantages and other embodiments of the invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A further understanding of the various embodiments of the present invention may be realized by reference to the figures which are described in remaining portions of the specification. In the figures, like reference numerals are used throughout several figures to refer to similar components. In some instances, a sub-label consisting of a lower case letter is associated with a reference numeral to denote one of multiple similar components. When reference is made to a reference numeral without specification to an existing sub-label, it is intended to refer to all such multiple similar components.
[0016] FIG. 1 shows a data processing circuit with out of order codeword processing circuitry and a feed forward calibration circuit in accordance with various embodiments of the present invention;
[0017] FIG. 2 is a flow diagram showing a method in accordance with some embodiments of the present invention for distributing calibration data in an out of order data processing circuit; and
[0018] FIG. 3 depicts a storage system including distributed calibration information in accordance with various embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present inventions are related to systems and methods for performing data calibration in an out of order data processing system.
[0020] Turning to FIG. 1 , a queuing detection and decoding circuit 100 including a feed forward calibration circuit is shown in accordance with various embodiments of the present invention. Queuing detection and decoding circuit 100 includes a data input 105 that is fed to a channel detector 109 . In some embodiments, data input 105 may be derived from a storage medium. In particular cases, data input 105 is provided as groups of data or data sets that are sometimes referred to as codewords. In the case of a hard disk drive, the received data sets may be sectors of data from the storage medium of the hard disk drive. Based upon the disclosure provided herein, one of ordinary skill in the art will recognize other sources for data input, and other data sets that may be processed in accordance with different embodiments of the present invention.
[0021] Channel detector 109 may be any type of channel detector known in the art including, but not limited to, a soft output Viterbi algorithm detector (SOVA) or a maximum a posteriori (MAP) detector. Based on the disclosure provided herein, one of ordinary skill in the art will recognize a variety of channel detectors that may be used in accordance with different embodiments of the present invention.
[0022] In addition, data input 105 is provided to a memory buffer 113 that is designed to hold a number of data sets received from data input 105 . The size of memory buffer 113 may be selected to provide sufficient buffering such that a data set provided via data input 105 remains available at least until a first iteration processing of that same data set is complete and the processed data is available in a queue buffer 149 as more fully described below. Memory buffer 113 provides the data sets to a channel detector 117 . Similar to channel detector 109 , channel detector 117 may be any type of channel detector known in the art including, but not limited to, a SOVA detector or a MAP detector. Again, based on the disclosure provided herein, one of ordinary skill in the art will recognize a variety of channel detectors that may be used in accordance with different embodiments of the present invention.
[0023] Additionally, data input 105 is provided to a feed forward calibration circuit that includes a calibration circuit 196 and a memory 194 . Data sets provided via data input 105 are processed by calibration circuit 196 as is known in the art. In some embodiments of the present invention, calibration circuit 196 includes a noise predictive finite impulse response filter and a variance calibration training circuit as are known in the art. Calibration circuit 196 estimates the parameters used to compute the branch metrics of channel detector 109 . These calculated parameters are referred to as data detection parameters. The data detection parameters are loaded into channel detector 109 at the end of each data set being processed by channel detector 109 , and are used in performing detection of the subsequent data set received by channel detector 109 via input data 105 . In addition, the calculated parameters are loaded into memory 194 at the end of each data set being processed by calibration circuit 196 . The calculated parameters may then be used to compute the branch metrics of channel detector 117 . Again, in some cases, the data set being processed is a codeword.
[0024] Memory 194 may be any storage device or circuitry known in the art. In one particular embodiment of the present invention, memory 194 is a single stage latch that receives the calculated parameters and holds them for processing in a subsequent channel detection process in channel detector 117 . As the processing by channel detector 109 and channel detector 117 do not necessarily start at the same time (e.g., the start of codeword processing by channel detector 109 occurs at a different time than the start of codeword processing by channel detector 117 ), memory 194 holds the calculated data detection parameters for loading into channel detector 117 at the end of each data set being processed by channel detector 117 .
[0025] An output 181 of channel detector 109 is provided to an interleaver circuit 194 , and an output 183 of channel detector 117 is provided to another interleaver circuit 192 . Interleaver circuit 194 interleaves the output of channel detector 109 using a ping pong buffer 197 , and interleaver circuit 192 interleaves the output of channel detector 117 using a ping pong buffer 198 . One of the buffers in ping pong buffer 197 holds the result of a prior interleaving process of the output from channel detector 109 and is unloaded to an LDPC decoder 137 via a multiplexer 121 , while the other buffer of ping pong buffer 197 holds a data set from channel detector 109 that is currently being interleaved. Similarly, one of the buffers in ping pong buffer 198 holds the result of a prior interleaving process of the output from channel detector 117 and is unloaded to LDPC decoder 337 via a multiplexer 121 , while the other buffer of ping pong buffer 198 holds a data set from channel detector 117 that is currently being interleaved. It should be noted that other soft decision data decoders may be used in place of LDPC decoder 137 in different embodiments of the present invention.
[0026] LDPC decoder 137 is capable of decoding one or more data sets simultaneously. As an example, LDPC decoder 137 may be designed to decode an interleaved data set from ping pong buffer 197 , to decode an interleaved data set from ping pong buffer 198 , or to decode interleaved data sets from ping pong buffer 197 and ping pong buffer 198 simultaneously. The decoded data is either provided as a hard decision output 141 or to a de-interleaver circuit 145 that uses queue buffer 149 to de-interleave the decoded data and to store the de-interleaved data until channel detector 117 is available for further processing.
[0027] Where the data converges, it is provided as a hard decision output 141 . Alternatively, where the data fails to converge, the data is stored to queue buffer 149 until channel detector 117 is available for further processing. One of the buffers in queue buffer 149 holds the result of a prior de-interleaving process and is unloaded to channel detector 117 , while another buffer of queue buffer 149 holds a decoded data set currently being de-interleaved, and one or more other buffers in queue buffer 149 maintain other non-converged data waiting for processing by channel detector 117 . Non-converged data from queue buffer 149 is de-interleaved by de-interleaver 145 and passed to channel detector 117 that has access to the corresponding data set in memory buffer 113 . The data detection performed by channel detector 117 is similar to that performed by channel detector 109 . The data detection is done using the calculated parameters stored in memory 194 . The calculated parameters are changed in memory 194 at the end of the processing of each data set by channel detector 109 , and are loaded from memory 194 to channel detector 117 at the end of the processing of each data set by channel detector 117 . Hard decision output 141 is provided to a de-interleaver circuit 157 that de-interleaves the received hard decision output 141 and stores the de-interleaved result in one of a number of memory buffers 161 . Ultimately, de-interleaver circuit 157 provides the de-interleaved data stored in memory buffers 161 as an output 171 . One function of de-interleaver 157 is to re-order the processed data sets so that they can be provided as an output in the same order that the corresponding data sets were originally received.
[0028] Queuing detection/decoding circuit 100 allows for performance of a variable number of detection and decoding iterations depending upon the introduced data. Further, in some cases, considerable power savings may be achieved through use of queuing detection/decoding circuit 100 . Yet further, in some cases, a faster LDPC decoder may be implemented allowing for an increased throughput where substantial first iteration data convergence exists as multiple iterations are not necessarily required. Yet further, by allowing results of LDPC decoder 137 to be reported out of order, upstream processing does not have to wait for the completion of downstream processing. Re-ordering of the out of order results may be done by queuing detection/decoding circuit 100 or by a downstream recipient of output 171 .
[0029] Where noise predictive calibration circuit 196 is a closed loop adaptive circuit as are known in the art, providing the most recent calculated parameters to both channel detector 109 and channel detector 117 assures that the most recent adaptation is available for performing data detection in channel detector 109 and channel detector 117 . Further, providing the same calculated parameters to both channel detector 109 and channel detector 117 , the circuitry may be minimized when compared to other circuits that use the calculated parameters in relation to the same data set as it is processed one or more times through channel detector 117 .
[0030] In operation, a first data set is introduced via data input 105 to channel detector 109 . Channel detector 109 performs its channel detection algorithm and provides both a hard output and a soft output to interleaver circuit 194 that interleaves the received data into one buffer of ping pong buffer 197 . As the data detection process proceeds in channel detector 109 , calibration circuit 196 performs a noise predictive calibration and variance calibration that calculates the parameters that will be used to compute the branch metrics of detector 109 and detector 117 . At the end of processing the first data set, the calculated parameters are loaded into detector 109 for use in relation to processing a subsequent data set through channel detector 109 , and into memory 194 for use in relation to processing a subsequent data set through channel detector 117 .
[0031] Interleaver 194 may interleave the data set by writing consecutive data into non-consecutive memory/buffer addresses based on the interleaver algorithm/mapping. Interleaved data is provided from the other buffer of ping pong buffer 197 to LDPC decoder 137 via multiplexer 121 . LDPC decoder 137 performs a data decoding process. Where the decoding process converges, LDPC decoder 137 writes its output as hard decision output 141 to output data buffer 161 and the processing is completed for that particular data set. Alternatively, where the data does not converge, LDPC decoder 137 writes its output (both soft and hard) to queue buffer 149 . The scheduling guarantees that there is at least one empty buffer for holding this new set of data, and this strategy assures that each data input is guaranteed the possibility of at least two global iterations (i.e., two passes through a detector and decoder pair). As the LDPC decoding process proceeds, LDPC decoder 137 asserts LDPC processing start signal 124 .
[0032] Where the data decoding process applied by LDPC decoder converges, the converging result is provided as a hard decision 141 to one of the buffers in memory buffer 161 . The outputs are re-ordered and presented as output 171 . Alternatively, where the data decoding process fails to converge, the non-converging data set is written to one of the buffers in queue buffer 149 . Channel detector 117 selects the data set that corresponds to the output in queue buffer 149 from input data buffer 113 and performs a subsequent data detection aided by the soft output data generated by LDPC decoder 137 fed back from queue buffer 149 . Before the channel detection process of channel detector 117 begins, the calculated parameters are loaded into channel detector 117 from memory 194 . This assures that the most recent calculated parameters are used by channel detector 117 . By using the previously generated soft data for data maintained in input data buffer 113 , channel detector 117 generally performs a subsequent channel detection with heightened accuracy. The output of this subsequent channel detection is passed to interleaver circuit 192 that interleaves the received data into one buffer of ping pong buffer 198 . Interleaver 192 may interleave the data set by writing consecutive data into non-consecutive memory/buffer addresses based on the interleaver algorithm/mapping. The interleaved data is provided from the other buffer of ping pong buffer 318 to LDPC decoder 137 via multiplexer 121 . LDPC decoder 137 provides another decoding pass to the data. Similar to the first iteration, a decision is made as to whether the data converged. Where the data converged, LDPC decoder 137 writes its output as hard decision output 141 to output data buffer 161 and the processing is complete for that particular data set. Alternatively, where the data does not converge, LDPC decoder 137 writes its output (both soft and hard) to queue buffer 149 where it is passed back to channel detector 117 for another global iteration where such is necessary and possible.
[0033] Turning to FIG. 2 , a flow diagram 200 shows a method in accordance with some embodiments of the present invention for distributing calibration data in an out of order data processing circuit. Following flow diagram 200 , a data input is received (block 220 ). This data input may be, but is not limited to, a series of data bits received from a magnetic recording medium or a series of bits received from a transmission channel. These series of data bits may be grouped into data sets. These data sets may include data grouped into a particular format and are referred to as codewords. For example, the data sets may include data assembled for low density parity check (LDPC) decoding that may be referred to as LDPC codewords. A sample of the received data is stored in a buffer and retained for later processing (block 225 ). In some cases, the data stored in the buffer is stored as a full sector of data, and the data buffer includes the ability to store multiple sectors of data.
[0034] In addition, a calibration process is performed on the received data input to calculate data detection parameters (block 226 ). The data detection parameters are used to compute the branch metrics in data detection processes. Calculation of such data detection parameters and use of the data detection parameters in the data detection processes are well known in the art. The process of calculating data detection parameters may include the use of noise predictive filters. The coefficients for the noise predictive filters are adaptively updated using previous values and the newly received data being processed by the noise predictive filters.
[0035] Data detection processes are performed on the received data to yield a detected data set (block 255 ). The data detection processes use data detection parameters calculated as part of block 226 . The calculated data detection processes and coefficients are stored to a memory (block 227 ). These stored data detection parameters are used in relation to subsequent data detection processes. The detected data set is interleaved (block 260 ), and the interleaved data is decoded (block 265 ). In some embodiments of the present invention, the data decoding is an LDPC decoding process as is known in the art. It is then determined whether the decoding process converged (block 245 ), and whether there is sufficient buffering available to reprocess the data (block 250 ).
[0036] Where either the decoding process converged (block 245 ) or there is insufficient buffering available (block 250 ), the decoded data is de-interleaved (block 270 ) and stored in a buffer (block 275 ). The buffer includes various processed data sets that may have become available out of order, and as such the various processed data sets are reordered in the buffer so that the completed data sets may be presented at the output in the same order that the unprocessed data sets were received at the input (block 280 ). It is then determined if a complete time set is available in the buffer (block 285 ). A complete time set includes every result corresponding to received inputs over a given period of time. Thus, for example, where the first result is delayed while two later results are reported, the complete time set exists for the three results once the first result is finally available in the buffer. Where a complete time set is available (block 285 ), the processed data set(s) are output to a recipient (block 290 ).
[0037] Alternatively, where the decoding process failed to converge (block 245 ) and there is sufficient buffering available (block 250 ), the process of detection and decoding is repeated for the particular data set. In particular, the decoded data is de-interleaved (block 205 ) and the resulting de-interleaved data is stored to a buffer (block 210 ). The data is accessed from the buffer and the de-interleaved data is aligned with the corresponding sample of the data input that was stored as described above in relation to block 225 (block 215 ) once the data detector is available. The de-interleaved data and the corresponding sample data input is provided to the data detector where a subsequent data detection is performed (block 230 ) on the originally stored sample of data input (block 225 ) using the soft input developed in the earlier processing of the same data input (blocks 255 , 260 , 265 , 245 , 250 , 205 , 210 , 215 ). The data detection of block 230 is performed using the data detection parameters previously stored in block 227 . The result of the data detection process is interleaved (block 235 ) and the interleaved data is decoded (block 240 ). At this point, it is determined whether the data detection and decoding process failed to converge (block 245 ) and is to be repeated, or whether the result converged (block 245 ) and is to be reported.
[0038] Turning to FIG. 3 , a storage system 300 is shown that includes a read channel 310 with calibration circuitry in accordance with various embodiments of the present invention. Storage system 300 may be, for example, a hard disk drive. Read channel 310 includes a data processing circuit with out of order codeword processing circuitry and a feed forward calibration circuit. In one embodiment of the present invention, the out of order codeword processing circuitry is similar to that described above in relation to FIG. 1 . In some cases, the read channel circuit operates similar to that discussed above in relation to FIG. 2 .
[0039] Storage system 300 also includes a preamplifier 370 , an interface controller 320 , a hard disk controller 366 , a motor controller 368 , a spindle motor 372 , a disk platter 378 , and a read/write head assembly 376 . Interface controller 320 controls addressing and timing of data to/from disk platter 378 . The data on disk platter 378 consists of groups of magnetic signals that may be detected by read/write head assembly 376 when the assembly is properly positioned over disk platter 378 . In one embodiment, disk platter 378 includes magnetic signals recorded as either longitudinal or perpendicular recorded signals.
[0040] In a typical read operation, read/write head assembly 376 is accurately positioned by motor controller 368 over a desired data track on disk platter 378 . The appropriate data track is defined by an address received via interface controller 320 . Motor controller 368 both positions read/write head assembly 376 in relation to disk platter 378 and drives spindle motor 372 by moving read/write head assembly to the proper data track on disk platter 378 under the direction of hard disk controller 366 . Spindle motor 372 spins disk platter 378 at a determined spin rate (RPMs). Once read/write head assembly 378 is positioned adjacent the proper data track, magnetic signals representing data on disk platter 378 are sensed by read/write head assembly 376 as disk platter 378 is rotated by spindle motor 372 . The sensed magnetic signals are provided as a continuous, minute analog signal representative of the magnetic data on disk platter 378 . This minute analog signal is transferred from read/write head assembly 376 to read channel 310 via preamplifier 370 . Preamplifier 370 is operable to amplify the minute analog signals accessed from disk platter 378 . In turn, read channel module 310 decodes and digitizes the received analog signal to recreate the information originally written to disk platter 378 . The read data is provided as read data 303 . A write operation is substantially the opposite of the preceding read operation with write data 301 being provided to read channel module 310 . This data is then encoded and written to disk platter 378 .
[0041] In conclusion, the invention provides novel systems, devices, methods and arrangements for performing data processing. While detailed descriptions of one or more embodiments of the invention have been given above, various alternatives, modifications, and equivalents will be apparent to those skilled in the art without varying from the spirit of the invention. For example, one or more embodiments of the present invention may be applied to various data storage systems and digital communication systems, such as, for example, tape recording systems, optical disk drives, wireless systems, and digital subscribe line systems. Therefore, the above description should not be taken as limiting the scope of the invention, which is defined by the appended claims.
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Various embodiments of the present invention provide systems and methods for updating detector parameters in a data processing circuit. For example, a data processing circuit is disclosed that includes a first detector circuit, a second detector circuit, and a calibration circuit. The first detector circuit is operable to receive a first data set and to apply a data detection algorithm to the first data set, and the second detector circuit is operable to receive a second data set and to apply the data detection algorithm to the second data set. The calibration circuit is operable to calculate a data detection parameter based upon a third data set. The data detection parameter is used by the first detector circuit in applying the data detection algorithm to the first data set during a period that the data detection parameter is used by the second detector circuit in applying the data detection algorithm to the second data set.
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[0001] The present invention relates to the use of 7-hydroxy-cannabidol (7-OH-CBD) and/or 7-hydroxy-cannabidivarin (7-OH-CBDV) in the treatment of epilepsy.
[0002] Preferably the cannabinoid metabolites are isolated from plants to produce a highly purified extract or can be reproduced synthetically.
BACKGROUND TO THE INVENTION
[0003] Epilepsy occurs in approximately 1% of the population worldwide, (Thurman et al., 2011) of which 70% are able to adequately control their symptoms with the available existing anti-epileptic drugs (AED). However, 30% of this patient group, (Eadie et al., 2012), are unable to obtain seizure freedom from the AED that are available and as such are termed as suffering from “treatment-resistant epilepsy” (TRE).
[0004] There are several different types of AED available to treat epilepsy, some of the most common AED defined by their mechanisms of action are described in the following tables:
Examples of Narrow Spectrum AED
[0005]
[0000]
Narrow-spectrum AED
Mechanism
Phenytoin
Sodium channel
Phenobarbital
GABA/Calcium channel
Carbamazepine
Sodium channel
Oxcarbazepine
Sodium channel
Gabapentin
Calcium channel
Pregabalin
Calcium channel
Lacosamide
Sodium channel
Vigabatrin
GABA
Examples of Broad Spectrum AED
[0006]
[0000]
Broad-spectrum AED
Mechanism
Valproic acid
GABA/Sodium channel
Lamotrigine
Sodium channel
Topiramate
GABA/Sodium channel
Zonisamide
GABA/Calcium/Sodium channel
Levetiracetam
Calcium channel
Clonazepam
GABA
Rufinamide
Sodium channel
[0007] Individuals who develop epilepsy during the first few years of life are often difficult to treat and as such are often termed treatment-resistant. Children who undergo frequent seizures in childhood are often left with neurological damage which can cause cognitive, behavioral and motor delays.
[0008] Childhood epilepsy is a relatively common neurological disorder in children and young adults with a prevalence of approximately 700 per 100,000. This is twice the number of epileptic adults per population.
[0009] When a child or young adult presents with a seizure, investigations are normally undertaken in order to investigate the cause. Childhood epilepsy can be caused by many different syndromes and genetic mutations and as such diagnosis for these children may take some time.
[0010] Childhood epilepsy refers to the many different syndromes and genetic mutations that can occur to cause epilepsy in childhood. Examples of some of these are as follows: Dravet Syndrome; Myoclonic-Absence Epilepsy; Lennox-Gastaut syndrome; Generalized Epilepsy of unknown origin; CDKL5 mutation; Aicardi syndrome; bilateral polymicrogyria; Dup15q; SNAP25; and febrile infection related epilepsy syndrome (FIRES); benign rolandic epilepsy; juvenile myoclonic epilepsy; infantile spasm (West syndrome); and Landau-Kleffner syndrome. The list above is non-exhaustive as many different childhood epilepsies exist.
Examples of AED Used Specifically in Childhood Epilepsy
[0011]
[0000]
AED
Mechanism
Clobazam
GABA
Stiripentol
GABA
[0012] The International League Against Epilepsy (ILAE) in 2011 have reclassified the old terms of “general” and “partial” seizures”. The new term “generalized seizure” refers to seizures conceptualized as originating at some point within the brain and rapidly engaging bilaterally distributed networks.
[0013] The new term “focal seizure” now refers to seizures conceptualized as originating at some point within the brain and being limited to one hemisphere.
[0014] The etiology of epilepsy has also been reclassified by the ILAE as being of genetic origin; structural or metabolic origin; or of unknown origin.
[0015] There is also now no specific classification for focal seizure types, therefore the terms complex partial and simple partial seizure are no longer in use.
[0016] There are several different animal models that can be used to test the efficacy of compounds as anti-convulsants. These include the pentylenetetrazole-induced (PTZ) model of generalised seizures and the Maximal Electroshock (MES) model of generalised seizures.
[0017] Over the past forty years there have been a number of animal studies on the use of the non-psychoactive cannabinoid cannabidiol (CBD) to treat seizures. For example, Consroe et al., (1982) determined that CBD was able to prevent seizures in mice after administration of pro-convulsant drugs or an electric current.
[0018] Studies in epileptic adults have also occurred in the past forty years with CBD. Cunha et al. reported that administration of CBD to eight adult patients with generalized epilepsy resulted in a marked reduction of seizures in 4 of the patients (Cunha et al., 1980).
[0019] A study in 1978 provided 200 mg/day of pure CBD to four adult patients, two of the four patients became seizure free, whereas in the remainder seizure frequency was unchanged (Mechoulam and Carlini, 1978).
[0020] Carlini et al. in 1981 described a further study where CBD was provided to healthy volunteers, insomniacs and epileptic patients. Seven out of the eight epileptic patients described an improvement in their condition.
[0021] In contrast to the studies described above, an open label study reported that 200 mg/day of pure CBD was ineffective in controlling seizures in twelve institutionalized adult patients (Ames and Cridland, 1986).
[0022] In the past forty years of research there have been over thirty drugs approved for the treatment of epilepsy none of which are cannabinoids. Indeed, there appears to have been a prejudice against cannabinoids, possible due to the scheduled nature of these compounds and/or the fact that THC, which is a known psychoactive, has been ascribed as a pro-convulsant (Consroe et al., 1977).
[0023] More recently the applicant has discovered that the cannabinoids CBD and CBDV are effective in animal models of epilepsy. For example EP 2,448,637 describes the use of CBD in the treatment of partial seizures and WO 2011/121351 describes the use of CBDV in the treatment of epilepsy. Hill et al. (2012) and Amada et al. (2013) both also describe the use of CBDV in the treatment of epilepsy. Jones et al. (2012) describes the anti-convulsant activity of CBD in animal models.
[0024] Furthermore GB 2495118 describes the use of a pharmaceutical composition comprising a combination of CBDV and CBD.
[0025] The synthetic production of the metabolite of CBD, 7-hydroxy-cannabidiol, (7-OH CBD) is disclosed in WO 01/95899 in addition to many other CBD derivatives. The compound was tested in a model of inflammation and found to be effective. The application goes on to suggest that the compound may be of use as an analgesic, anti-anxiety, anti-convulsant, neuroprotective, anti-psychotic and anti-inflammatory based on the mechanisms the compound displays in the model of inflammation. However no data is presented to support the use of 7-OH-CBD as an anti-convulsant.
[0026] To date there have been no studies into the anti-convulsant effect of metabolites of CBD and CBDV.
[0027] Surprisingly, it has now been found that a metabolite of CBD, 7-hydroxy-cannabidiol, (7-OH CBD) and a metabolite of CBD, 7-hydroxy-cannabidivarin, (7-OH CBDV) are effective in the treatment of epilepsy. The metabolites appear to be more effective than their parent compounds in certain aspects of seizure control.
BRIEF SUMMARY OF THE DISCLOSURE
[0028] In accordance with a first aspect of the present invention there is provided 7-hydroxy-cannabidivarin (7-OH-CBDV) in a pure, isolated or synthetic form for use as a medicament.
[0029] In accordance with a second aspect of the present invention there is provided 7-hydroxy-cannabidivarin (7-OH-CBDV) in a pure, isolated or synthetic form for use in the treatment of epilepsy.
[0030] In accordance with a third aspect of the present invention there is provided 7-hydroxy-cannabidol (7-OH-CBD) in a pure, isolated or synthetic form for use in the treatment of epilepsy.
[0031] In one embodiment the 7-hydroxy-cannabidivarin (7-OH-CBDV) in a pure, isolated or synthetic form is used in combination with 7-hydroxy-cannabidol (7-OH-CBD) in a pure, isolated or synthetic form.
[0032] In accordance with a fourth aspect of the present invention there is provided a pharmaceutical composition comprising 7-hydroxy-cannabidivarin (7-OH-CBDV) and/or 7-hydroxy-cannabidol (7-OH-CBD) with a pharmaceutically acceptable carrier.
[0033] In accordance with a fifth aspect of the present invention there is provided a pharmaceutical composition comprising 7-hydroxy-cannabidivarin (7-OH-CBDV) and/or 7-hydroxy-cannabidol (7-OH-CBD) with a pharmaceutically acceptable carrier for use in the treatment of epilepsy.
[0034] In one embodiment the 7-hydroxy-cannabidol (7-OH-CBD) and/or 7-hydroxy-cannabidivarin (7-OH-CBDV) are used in combination with one or more concomitant anti-epileptic drugs (AED).
[0035] Preferably the one or more AED is selected from the group consisting of: clobazam; levetiracetam; topiramate; stiripentol; phenobarbital; lacsamide; valproic acid; zonisamide; perampanel; and fosphenytoin.
[0036] Preferably the dose of 7-OH-CBD and/or the 7OH-CBDV is between 1 and 2000 mg/kg.
[0037] Preferably the 7-OH-CBDV may be formulated for administration separately, sequentially or simultaneously with the 7-OH-CBD or the combination may be provided in a single dosage form.
[0038] It is envisaged that the composition be administered as an oral liquid solution. Other modes of administration including solids, semi-solids, gels, sprays, aerosols, inhalers, vaporisers, enemas and suppositories are alternative administration forms. Such medicaments could be administered via the oral, buccal, sublingual, respiratory, nasal and distal rectum route.
[0039] In accordance with a sixth aspect of the present invention there is provided a method of treating epilepsy comprising administering a therapeutically effective amount of 7-hydroxy-cannabidiol (7-OH-CBD) and/or 7-hydroxy-cannabidivarin (7-OH-CBDV) to a subject in need thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:
[0041] FIG. 1 shows CBDV and CBD, and their 7-OH metabolites in the PTZ model of acute seizure.
LEGEND TO THE FIGURES
[0042] FIG. 1 . CBDV and 7-OH CBDV were dosed at 200 mg/kg, and CBD and 7-OH CBD were dosed at 100 mg/kg (A) Maximum observed seizure severity (median severity in grey, box represents interquartile range, whiskers represent maxima and minima; Kruskal-Wallis test, with a post-hoc Mann-Whitney U) (B) Mortality (Chi-squared test, with a post-hoc Fisher exact) (C) Animals exhibiting tonic-clonic seizures (Chi-squared test, with a post-hoc Fisher exact) (D) Latency to seizure onset (median with interquartile range; Kruskal-Wallis test, with a post-hoc Mann-Whitney U). n=11 for each dose, *=≦0.05, **=p≦0.01.
DEFINITIONS
[0043] Definitions of some of the terms used to describe the invention are detailed below:
[0044] The cannabinoids described in the present application are listed below along with their standard abbreviations.
[0000]
CBD
Cannabidiol
7-OH-CBD
7-hydroxy-cannabidiol
CBDV
Cannabidivarin
7-OH-CBDV
7-hydroxy-cannabidivarin
[0045] The table above is not exhaustive and merely details the cannabinoids which are identified in the present application for reference. So far over 60 different cannabinoids have been identified and these cannabinoids can be split into different groups as follows: Phytocannabinoids; Endocannabinoids and Synthetic cannabinoids (which may be novel cannabinoids or synthetically produced phytocannabinoids or endocannabinoids).
[0046] “Cannabinoid metabolites” are metabolites from cannabinoids that originate when the parent cannabinoid is metabolised or broken down. The cannabinoid metabolites can be isolated from plants to produce a highly purified extract or can be reproduced synthetically.
[0047] “Highly purified cannabinoid metabolites” are defined as cannabinoids that have been extracted from the cannabis plant and purified to the extent that other cannabinoids and non-cannabinoid components that are co-extracted with the cannabinoids have been removed, such that the highly purified cannabinoid is greater than 90%, more preferably greater than 95%, most preferably greater than 98% (w/w) pure.
[0048] The cannabinoid metabolites may be manufactured synthetically and/or produced from the parent cannabinoid by enzymatic means.
[0049] Phytocannabinoids can be obtained as either the neutral (decarboxylated form) or the carboxylic acid form depending on the method used to extract the cannabinoids. For example it is known that heating the carboxylic acid form will cause most of the carboxylic acid form to decarboxylate into the neutral form.
[0050] The human dose equivalent (HED) can be estimated using the following formula:
[0000]
HED
=
Animal
dose
(
mg
/
kg
)
multiplied
by
Animal
K
m
Human
K
m
The K m for a rat is 6 and the K m for a human is 37.
Thus, for a human of approximately 60 Kg a 200 mg/Kg dose in rat would equate to a human daily dose of about 2000 mg.
DETAILED DESCRIPTION
[0053] The following Examples describe for the first time the anti-convulsant activity of the metabolites of CBD, namely 7-OH-CBD and CBDV, namely, 7-OH-CBDV.
EXAMPLE 1
Efficacy of 7-Hydroxy Cannabidiol (7-OH-CBD) and 7-Hydroxy Cannabidivarin (7-OH-CBDV) in the Ptz Model of Seizure
Materials and Methods
Compounds:
[0054] The compounds 7-OH CBD and 7-OH-CBDV have never been tested in a model of epilepsy and as such the effects were examined at one dose level in order to determine efficacy.
[0055] The hydroxy-metabolites of CBD and CBDV were also tested against their parent cannabinoids which were used as positive controls. The table below details the doses used in this study.
[0000]
Compound
Dose (mg/kg)
Vehicle
—
CBDV
200
7-OH-CBDV
200
CBD
100
7-OH CBD
100
General Methodology for PTZ Model
Animals
[0056] Male Wistar rats (P24-29; 75-110 g) were used to assess the effects of the cannabinoids listed above on the PTZ model of generalised seizures. Animals were habituated to the test environment, cages, injection protocol and handling prior to experimentation. Animals were housed in a room at 21° C. on a 12 hour light: dark cycle (lights on 0900) in 50% humidity, with free access to food and water.
Experimental Setup
[0057] Five 6 L Perspex® tanks with lids were placed on a single bench with dividers between them. Closed-circuit television (CCTV) cameras were mounted onto the dividers to observe rat behaviour. Sony Topica CCD cameras (Bluecherry, USA) were linked via BNC cables to a low-noise PC via Brooktree digital capture cards (Bluecherry, USA). Zoneminder (http://www.zoneminder.com) software was used to monitor rats, start and end recordings and manage video files. In-house Linux® scripts were used to encode video files into a suitable format for further offline analysis
Experimental Protocols
[0058] On the day of testing, animals received an IP injection with either the cannabinoids (or a matched volume of the cannabinoids vehicle (1:1:18 ethanol:Cremophor: 0.9% w/v NaCl solution), which served as the negative control group. Animals were then observed for 30 mins, after which time they received an IP injection of 70 or 80 mg/kg PTZ. Negative vehicle controls were performed in parallel with cannabinoid-dosed subjects. After receiving a dose of PTZ, animals were observed and videoed to determine the severity of seizure and latency to several seizure behaviour types (see in vivo analysis, below). Animals were filmed for half an hour after last sign of seizure, and then returned to their cage.
In Vivo Analysis
[0059] Animals were observed during experimental procedures, but all analysis was performed offline on recorded video files using The Observer behavioural analysis software (Noldus, Netherlands). A seizure severity scoring system was used to determine the levels of seizure experienced by subjects (Table 1). All signs of seizure were detailed for all animals.
[0000] TABLE 1 Seizure severity scoring scale Seizure score Behavioural expression Righting reflex 0 No changes to behaviour Preserved 0.5 Abnormal behaviour (sniffing, Preserved excessive washing, orientation) 1 Isolated myoclonic jerks Preserved 2 Atypical clonic seizure Preserved 3 Fully developed bilateral Preserved forelimb clonus 3.5 Forelimb clonus with tonic Preserved component and body twist 4 Tonic-clonic seizure with Lost suppressed tonic phase 5 Fully developed tonic-clonic Lost seizure 6 Death
Latency from Injection of PTZ to Specific Indicators of Seizure Development:
[0060] The latency (in seconds) from injection of PTZ to first myoclonic jerk (FMJ; score of 1), and to the animal attaining “forelimb clonus with tonic component and body twist” (score of 3.5) were recorded. FMJ is an indicator of the onset of seizure activity, whilst >90% of animals developed scores of 3.5, and so is a good marker of the development of more severe seizures. Data are presented as the mean±S.E.M. within an experimental group.
Maximum Seizure Severity:
[0061] This is given as the median value for each experimental group based on the scoring scale above.
Percentage Mortality:
[0062] The percentage of animals within an experimental group that died as a result of PTZ-induced seizures. A score of 6 (death) automatically denotes that the animal also experienced tonic-clonic seizures.
Seizure Duration:
[0063] The time (in seconds) from the first sign of seizure (typically FMJ) to either the last sign of seizure or, in the case of subjects that died, the time of death—separated into animals that survived and those that did not. This is given as the mean±S.E.M. for each experimental group.
Statistics:
[0064] Differences in latencies and durations were assessed by one-way analysis of variance (ANOVA) with post-hoc Tukey's test. P≦0.05 was considered significant.
Results
[0065] FIG. 1A shows that treatment with all of the compounds, both parents and metabolites resulted in a decrease the observed maximum seizure severity. CBDV significantly reduced seizure severity (p≦0.01).
[0066] FIG. 1B shows that CBDV and 7-OH-CBDV had a significant effect on mortality of the animals. There was also a reduction in mortality observed for CBD and 7-OH-CBD.
[0067] FIG. 1C demonstrates that the incidence of tonic clonic seizures was significantly reduced by CBDV and to a lesser extent 7-OH-CBDV.
[0068] FIG. 1D demonstrates that the latency to the onset of seizures was also affected by the administration of cannabinoids. Indeed 7-OH CBD significantly reduced the latency to seizure onset (p≦00.01).
Conclusions
[0069] These results demonstrate that both 7-OH-CBD and 7-OH-CBDV show anti-convulsant action in the PTZ model of acute seizure.
[0070] Furthermore the ability 7-OH-CBD to significantly reduce the latency to onset of seizures and of 7-OH-CBDV to significantly reduce the median seizure severity, from 5 to 3 are remarkable as these data infer that the metabolites may be more effective than their parent compounds in certain aspects of seizure control.
[0071] The fact that the 7-OH-CBD and 7-OH-CBDV appear to be more potent than their parent cannabinoids, CBD and CBDV respectively, means that lower doses of the metabolites may be used in the treatment of epilepsy.
EXAMPLE 2
Efficacy of 7-Hydroxy Cannabidivarin (7-OH-CBDV) in the Maximal Electroshock (Mes) Model of Seizure
Preparation of Test and Reference Compounds
[0072] The vehicle used in this study was 2:1:17 (ethanol:Cremophor:0.9% w/v NaCl). The test compound used was 7-OH-CBDV. This was made to a solution at the highest concentration; then dissolved in ethanol before combination with Cremophor and 0.9% NaCl in the proportion described above. The 7-OH-CBDV was administered intraperitoneally at a volume of 10 ml/kg body weight.
Test System
[0073] Animal Species/Strain: Mouse/ICR, Microbiological grade: SPF, Inc. Sex: male, Age (at time of testing): 5-7 weeks old, Number of animals: about 5 animals per group. Temperature: 23±2° C., Humidity: 60±10%, Light conditions: 7 AM to 7 PM for the light period, 7 PM to 7 AM for the dark period. Chow and water: Free access to CRF-1 (Oriental Yeast Co, Ltd) and tap water.
Experimental Procedures
[0074] One day before each experiment, mice were weighed and randomized into several groups in each test. On the morning of the experiment day, body weight was measured in order to calculate the administration volume of each animal. Vehicle, 7-OH-CBDV or CBDV was interperitoneally administered 30 minutes before electric stimuli. Maximal electroshock seizures (MES) in mice was induced by a stimulator (UGO BASILE ECT UNIT 7801, Italia) using a current of 30 mA delivered with a pulse frequency of 100 Hz for 200 msec through earlap electrodes. The mice were observed for 10 seconds and the incidence of tonic hindlimb extension was noted.
Statistical Analysis
[0075] All statistical analyses were performed using SAS Software for Windows, Release 9.1. The difference of the number (hindlimb extension or deaths) in each group was assessed using two-tailed Fisher's exact test. The differences were considered statistically significant, when the p value was less than 0.05.
Results
[0076] Table 2 below demonstrates that the data obtained for the 7-OH-CBDV was statistically significant when compared to vehicle. Similarly to the parent compound, CBDV, 7-OH-CBDV at both doses produced a decrease in 90% of tonic clonic convulsions.
[0000]
TABLE 2
Percentage decrease in tonic clonic convulsions
Percentage decrease in
tonic clonic convulsions
Compound (dose)
compared with vehicle
Vehicle
—
7-OH-CBDV (150 mg/kg i.p.)
90%***
7-OH-CBDV (200 mg/kg i.p.)
90% ***
CBDV (200 mg/kg i.p.)
82% ***
*** = p < 0.001
Conclusion
[0077] These data further demonstrate the surprising ability of the primary metabolite of CBDV, 7-OH-CBDV to produce anti-convulsant effects.
REFERENCES
[0000]
Amada et al. (2013) PeerJ, 2013, pages 1-18 “Cannabidivarin (CBDV) suppresses pentylenetetrazole (PTZ)-induced increases in epilepsy-related gene expression”.
Ames F R and Cridland S (1986). “Anticonvulsant effects of cannabidiol”. S Afr Med J 69:14.
Carlini et al. (1981) Journal of Clinical Pharmacology, vol. 21, No. 8/9, 1981, pages 417S-427S “Hypnotic and antiepileptic effects of cannabidiol”.
Consroe P, Martin P, Eisenstein D. (1977). “Anticonvulsant drug antagonism of delta-9-tetrahydrocannabinol induced seizures in rabbits”. Res Commun Chem Pathol Pharmacol. 16:1-13
Consroe P, Benedicto M A, Leite J R, Carlini E A, Mechoulam R. (1982). “Effects of cannabidiol on behavioural seizures caused by convulsant drugs or current in mice”. Eur J Pharmaco. 83: 293-8
Cunha J M, Carlini E A, Pereira A E, Ramos O L, Pimental C, Gagliardi R et al. (1980). “Chronic administration of cannabidiol to healthy volunteers and epileptic patient”. Pharmacology. 21:175-85
Hill et al. (2012) British Journal of Pharmacology, vol. 167, No. 8, 2012, pages 1629-1642 “Cannabidivarin is anticonvulsant in mouse and rat”.
Jones et al. (2012) Seizure, vol. 21, No. 5, 2012, pages 344-352 “Cannabidiol exerts anti-convulsant effects in animal models of temporal lobe and partial seizures”.
Mechoulam R and Carlini E A (1978). “Toward drugs derived from cannabis.” Die naturwissenschaften 65:174-9.
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The present invention relates to the use of 7-hydroxy-cannabidol (7-OH-CBD) and/or 7-hydroxy-cannabidivarin (7-OH-CBDV) in the treatment of epilepsy. Preferably the cannabinoid metabolites are isolated from plants to produce a highly purified extract or can be reproduced synthetically.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a polymer composite and formed articles thereof. More particularly, the invention relates to a polymer composite which is inexpensive, can be obtained from a short process, and is excellent in flexibility, durability, and injection molding properties. More precisely, the invention relates to an elastomer material useful for rubber contacts.
2. Description of the Prior Art
As elastomers for rubber contacts excellent in flexibility and durability, hitherto, silicone rubber has been known. Resins designed to have same performance as the silicone rubber have been proposed. For example, a composite of polyester and nylon was disclosed in the Japanese Patent Application Laid-Open No. 55054/1985, a composite of thermoplastic polyurethane and nitrile rubber etc. in the Japanese Patent Application Laid-Open No. 207757/1991, a composite of polyolefin and polyurethane in the U.S. Pat. No. 3,969,475, and a composite of thermoplastic resin such as polypropylene and polyurethane in the Japanese Patent Application Laid-Open No. 227459/1990.
However, the silicone rubber, although excellent in flexibility and durability, involves many problems in economy, working efficiency and productivity, such as higher price as compared with general-purpose elastomers, shorter pot life, and long curing time. On the other hand, the polyester composite, nylon composite, and nitrile rubber composite mentioned above are less expensive than the silicone rubber, but possess such demerits as low flexibility and durability, and long processes required for manufacture of the composites. Yet, since one resin component is not sufficiently dispersed in the other resin component, they have problem such as low durability.
The composites disclosed in the U.S. Pat. No. 3,969,475 and the Japanese Patent Application Laid-Open No. 227459/1990 are sufficient in flexibility, but are inferior in repeated bending strength due to insufficient dispersion.
Thus, these composites do not satisfy the requirements for economy, flexibility and durability, especially as the polymer materials for rubber contacts.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a polymer composite which possesses flexibility and durability equivalent to those of silicone rubber, excels in injection molding properties, and can be manufactured at low cost.
It is another object of the invention to provide a polymer composite which has a short manufacturing process, is easy to manufacture, and is excellent in productivity.
It is still another object of the invention to provide a polymer composite useful as rubber contacts or the like for electric products such as elastic connectors or the like.
It is a further object of the invention to provide a composition for molding which comprises a polymer composite and an electroconductive filler, and molded articles made therefrom.
A still further object of the invention is to provide rubber contacts used as electric connection members for electric products.
Namely, the present invention provides a polymer composite which comrises about 5 to 95 parts by weight of a copolymer (A) selected from the group consisting of olefin/diene copolymer and ethylene/(meth)acrylic acid ester copolymer, and 5 to 95 parts by weight of a polyurethane resin (B), wherein the polyurethane resin is one which is synthesized in the melted copolymer in the absence of a compatibilizer, and molded articles manufactured from such a composite.
The invention also relates to a composition for molding comprising the polymer composite and an electroconductive filler.
The invention further relates to molded articles from a composition for molding comprising the polymer composite and an electroconductive filler.
The invention still further relates to rubber contacts comprising the polymer composite and an electroconductive filler.
DETAILED DESCRIPTION OF THE INVENTION
As the olefin component in the olefin-diene copolymer in the present invention, olefins having two to five carbon atoms, such as ethylene, propylene, 1-butene, 2-butene, and isobutylene etc. are used. The preferred one is isobutylene.
As the diene monomer component in the olefin-diene copolymer, dienes such as butadiene, isoprene, 2,3-butadiene, cyclopentadiene and chloroprene etc. are used. The preferred one is isoprene.
The ratio of the olefin and the diene component in the olefin/diene copolymer is usually 99.5:0.5 to 50:50 by mole ratio, and preferably 99:1 to 90:10.
As the (meth)acrylate component in the ethylene/(meth)acrylate copolymer, methyl-, ethyl-, butyl- or hexyl-esters of acrylic acid or methacrylic acid may be used. Methyl- or ethyl-esters of acrylic acid or methacrylic acid are preferable. Here, "(meth)acryl - - - " means "acryl - - - " and/or "methacryl - - - ", and this is the same hereinafter.
The ratio of the ethylene component and the (meth)acrylate component in the ethylene/(meth)acrylate copolymer is generally 10:90 to 90:10 by mole ratio, and preferably 10:90 to 50:50.
The weight-average molecular weight of the olefin/diene copolymer or the ethylene/(meth)acrylate copolymer (A) in the present invention is usually 10,000 to 3,000,000, or preferably 10,000 to 1,000,000.
In the above mentioned copolymers (A), the olefin/diene copolymer is preferable, and an isobutylene/isoprene copolymer is particularly preferable.
As the polyisocyanate component (B1) used in synthesis of polyurethane resin (B) in the present invention, materials such as aromatic diisocyanate (tolylene diisocyanate, xylylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate, etc.); aliphatic diisocyanate (hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, lysine diisocyanate, etc.); alicyclic diisocyanate (1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, 1,3-diisocyanatomethyl cyclohexane, etc.); aliphatic diisocyanate having an aromatic ring (xylylene diisocyanate, tetramethyl xylylene diisocyanate, etc.); and their modified diisocyanates (diisocyanates having carbodiimide group, uretidione group, urethimine group, biuret group, and/or isocyanurate ring etc.), and mixture of two or more thereof are mentioned as examples. Aromatic diisocyanates are particularly preferable.
As high molecular weight polyol components (B2) used in the synthesis of polyurethane resin (B) in the present invention, there can be used polyester polyols [as obtained by condensation polymerization of aliphatic dicarboxylic acid (succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.) and/or aromatic dicarboxylic acid (isophthalic acid, terephthalic acid, etc.) with low molecular weight glycols (ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexane diol, 3-methyl-1,5-pentane diol, neopentyl glycol, 1,4-dihydroxymethyl cyclohexane, etc.)], such as polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene/butylene adipate diol, poly-3-methylpentane adipate diol, polybutylene isophthalate diol; polyether polyols [as obtained by polymerization or copolymerization of an alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) and/or heterocyclic ether (tetrahydrofurane, etc.)], such as polyethylene glycol, polypropylene glycol, polyethylene-polypropylene glycol (block or random copolymer), polyethylene-polytetramethylene glycol (block or random copolymer), polytetramethylene ether glycol, polyhexamethylene ether glycol, etc.; polylactone polyols (e.g. polycaprolactone diol or triol, poly-3-methylvalerolactone diol); polycarbonate polyols (e.g. polyhexamethylene carbonate diol); polyolefin polyols (e.g. polybutadiene glycol, polyisopreneglycol, or those hydrogenated products); and mixtures of two types or more thereof.
A favorable polyol component among them is polyester diol obtained by condensation of aliphatic dicarboxylic acid and low molecular weight glycol.
In the manufacture of the polyurethane resin (B), a chain extender (B3) may be used as required. As the chain extender (B3), low molecular weight polyol and polyamine may be used. Examples of low molecular weight polyols include glycol listed as the material for the polyester polyol above and their low molecular weight alkylene oxide adducts (molecular weight less than 500); low molecular weight alkylene oxide adducts to bisphenol (molecular weight less than 500); trivalent alcohol, such as glycerin, trimethylol ethane, trimethylol propane, and their low molecular weight alkylene oxide adducts (molecular weight less than 500); and mixtures of two types or more thereof. Examples of polyamine include aliphatic polyamine, such as ethylene diamine, N-hydroxyethyl ethylene diamine, tetramethylene diamine, hexamethylene diamine, diethylene triamine, etc.; alicyclic polyamine, such as 4,4'-diaminodicyclohexyl methane, 1,4-diaminocyclohexane, isophorone diamine, etc.; aliphatic polyamine having an aromatic ring, such as xylylene diamine, tetramethyl xylylene diamine, etc.; aromatic polyamine, such as 4,4'-diaminodiphenyl methane, tolylene diamine, benzidine, phenylene diamine, etc.; and mixtures of two or more thereof. When the chain extender (B3) is used, the content is generally 0.3 to 30 wt. % of the high molecular polyol, preferably 0.5 to 20 wt. %.
In the manufacture of polyurethane resin (B), a catalyst may be also used as required. As the catalyst, any known catalyst for the urethane forming reaction may be used, for example, organic metal compounds such as dibutyl tin dilaurate and dioctyl tin laurate, and amines such as triethylamine, triethylene triamine and diazabicycloundecene etc.
The ratio by weight of copolymer (A) and polyurethane resin (B) in the polymer composite of the present invention is generally 5:95 to 95:5, preferably 5:95 to 50:50. More preferably, the ratio is 10:90 to 40:60. If the content of the copolymer (A) is less than 5, the hardness is too high, and the obtained composite lacks in flexibility, or if the content of the copolymer (A) exceeds 95, the impact resilience is poor, and when the obtained composite is used in rubber contacts, the touch is inferior, and the injection molding properties are lowered.
The polymer composite of the invention is obtained by reaction of (B1) and (B2), and also with (B3) if necessary, in the presence of the melted copolymer (A). The reaction is carried out without a compatibilizer.
In the case of reaction of (B1) and (B2), and with (B3) if necessary, in the presence of the melted copolymer (A), the temperature is usually 10° to 350° C., or preferably 100° to 300° C. The reaction pressure is not particularly limited, but considering the industrial production, it is usually 0 to 20 atmospheres, or preferably 0 to 10 atmospheres (at gauge pressure). The reaction time should be as short as possible, in order that thermal deterioration of the resulted polyurethane resin may not occur during reaction, and is usually 0.5 to 60 minutes, preferably 1 to 30 minutes.
As the reaction vessel for manufacturing the polymer composite of the invention, any known mixer is usable, for example, extruder, kneader, Banbury mixer, and planetary mixer.
The molding method for the polymer composite of the invention is not particularly defined, and any known method may be applied. For example, the injection molding method, extrusion molding method, and compression molding method may be employed. From the viewpoint of working efficiency and productivity, the injection molding method is preferred.
The composite of the invention may contain, if necessary, electroconductive fillers, mold release agents, coloring agents, foaming agents, weather resistant stabilizers, lubricants, plasticizers, coupling agents, heat resistant stabilizers, flame retardants, and the like.
As the electroconductive fillers, fine powders of copper oxide and carbon black etc. are used.
As the mold release agents, silicone oil, ester of stearic acid or its metal salt, wax, and other higher aliphatic hydrocarbon etc. are used.
As the coloring agents, inorganic pigments such as carbon black, titanium oxide and calcium carbonate, and organic pigments such as phthalocyanin and Quinacridone Red are exemplified.
As the foaming agents, azo compound such as azobisisobutylonitrile, nitroso compounds such as dinitrosopentamethylene tetramine, and sulfonyl hydrazide compounds such as p-toluene sulfonyl hydrazide are exemplified.
As the weather resistant stabilizers, salicylates such as phenyl salicylate, benzophenone derivatives such as 2,4-dihydroxybenzophenone, benzotriazole derivatives such as 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, and cyanoacrylate esters such as 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate are exemplified.
As the lubricants, higher fatty acids are exemplified, such as liquid paraffin and stearic acid.
As the plasticizers, phosphate esters such as tributyl phosphate, phthalate esters such as dimethyl phthalate, and higher fatty acid esters such as butyl oleate are exemplified.
As the coupling agents, silane type coupling agents such as γ-methacryloxy propyl trimethoxy silane, and titanate type coupling agents such as isopropyl triisostearoyl titanate are exemplified.
As the heat resistant stabilizers, phenol derivatives such as butyl hydroxy annisol, sulfur containing compounds such as dilauryl thiodipropionate, and phosphate esters such as triphenyl phosphite are exemplified.
As the flame retardants, halogen compounds such as 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and phosphorus compounds such as ammonium phosphate are exemplified.
Rubber contacts are, meanwhile, tactile switches for sending electric signals used in electric and electronic products such as electronic desktop calculator, electronic keyboard, and personal computer. In other words, they are rubber pushbutton switch elements, and are usually divided into the inner type and key top type by the contact structure. Both feature tactile feedback characteristics with a crisp sharp-click operation. Such switches must be electroconductive, and the single-key construction in which the button itself is electroconductive, and the double construction consisting of an insulation layer and electroconductive layer are both employed generally.
The composite of the invention, when applied in rubber contacts, is desired to possess the mechanical properties of hardness of 50 to 75 (conforming to JIS A of JIS K 6301), impact resilience of 50 to 75%, tensile strength of 80 to 150 kg/cm 2 , and 100% stress of 20 to 50 kg/cm 2 . If the impact resilience is less than 50% and the hardness exceeds 75, the touch as rubber switches is inferior, or if the hardness is less than 50 and the impact resilience is over 75%, injection molding properties are lowered.
The composite having such mechanical properties is obtained, for example, by melting and kneading 40 parts by weight of isobutylene/isoprene rubber, 46 parts by weight of hydroxy-terminated polyethylene adipate, 2 parts by weight of 1,4-butanediol, and 12 parts by weight of diphenyl methane diisocyante, in a twin-shaft extruder, at a cylinder temperature of 210° C. It is also obtained by melting and kneading 10 parts by weight of isobutylene/isoprene rubber, 73 parts by weight of hydroxy-terminated polyethylene adipate, 3 parts by weight of 1,4-butanediol, and 14 parts by weight of diphenyl methane diisocyanate, in a twin-shaft extruder, at a cylinder temperature of 210° C.
The polymer composite of the invention possesses the flexibility and durability equivalent to those of silicone rubber, and is excellent in injection molding properties and inexpensive. Besides, the polymer composite of the invention can be manufactured in a short manufacturing process because it can be obtained by a one-shot polymerization technique. Furthermore, the polymer composite of the invention has excellent repeated bending strength because both polymers are uniformly dispersed microscopically.
The composite of the invention is particularly suitable to rubber contacts for electronic calculators, electronic keyboards, computers and word processors. It is also usable as rubber contacts for electric household appliances and sheets for keyboard cover.
The invention is further described below by referring to examples, but it must be noted that the invention is not limited to these examples alone. In the following description, the parts denote the parts by weight.
The measuring methods of hardness, impact resilience, tensile strength, 100% stress and dispersibility of examples and comparative examples listed in Table 1 are as follows.
(1) Hardness
Conforming to JIS K 6301 (JIS A and D).
(2) Impact resilience
Conforming to JIS K 6301.
Unit: %
(3) Tensile strength and 100% stress
Conforming to JIS K 6301.
Unit: kg/cm 2
(4) Dispersibility
Evaluated from SEM (scanning electron microscope) photograph of test piece.
EXAMPLE 1
40 parts of isobutylene-isoprene rubber [the containing ratio of isobutylene and isoprene is 98:2 (mole ratio), weight-average molecular weight 100,000, "JSR Butyl 365" manufactured by Japan Synthetic Rubber Co., Ltd., hereinafter abbreviated IIR], 46 parts of hydroxy-terminated polyethylene adipate [number-average molecular weight 2,000, hereinafter abbreviated PEA], 2 parts of 1,4-butanediol [hereinafter abbreviated 1,4-BG], and 12 parts of diphenyl methane diisocyanate [hereinafter abbreviated MDI] were melted and kneaded for five minutes in a twinshaft extruder [model 2D25-S of Toyo Seiki Seisakusho, 20 mm φ, L/D=25] at 210° C. (cylinder temperature), and the composite of the invention was obtained.
The obtained composite was injection molded at a cylinder temperature of 200° C. and metal mold temperature of 50° C., and a test piece was prepared. In this test piece, the hardness, impact resilience, tensile strength, and 100% stress were evaluated. The characteristics are shown in Table 1.
EXAMPLE 2
10 parts of IIR, 73 parts of PEA, 3 parts of 1,4-BG, and 14 parts of MDI were melted and kneaded for five minutes in the twin-shaft extruder of Example 1 at a cylinder temperature of 210° C., and the composite of the invention was obtained.
The obtained composite was injection molded at a cylinder temperature of 200° C. and metal mold temperature of 50° C., and a test piece (No. 3, JIS K 6301) was prepared. In this test piece, the hardness, impact resilience, tensile strength, 100% stress, and dispersibility were evaluated. The characteristics are shown in Table 1.
EXAMPLE 3
40 parts of IIR, 46 parts of PEA, 2 parts of 1,4-BG, 12 parts of MDI, and 5 parts of carbon black were melted and kneaded for five minutes in the twin-shaft extruder of Example 1 at a cylinder temperature of 210° C., and the composite of the invention was obtained.
The obtained composite was injection molded at a cylinder temperature of 200° C. and die temperature of 50° C., and a test piece (No. 3, JIS K 6301) was prepared. In this test piece, the hardness, impact resilience, tensile strength, and 100% stress were evaluated. The characteristics evaluation results are shown in Table 1.
EXAMPLE 4
40 parts of ethylene/methylacrylate copolymer (YUKALON-EMA XG-200M manufactured by Mitsubishi Petrochemical Company, Ltd.), 46 parts of PEA, 2 parts of 1,4-BG, and 12 parts of MDI were melted and kneaded for five minutes, by using the twin-shaft extruder, at a cylinder temperature of 210° C. Its characteristics evaluation results are shown in Table 1.
EXAMPLE 5
By injection molding of the composite obtained in Example 1 at a cylinder temperature of 200° C. and metal mold temperature of 50° C., rubber contacts were obtained. In the obtained rubber contacts, the click rate was 50%, and the click rate after repeated use of 100,000 times was 48%.
COMPARATIVE EXAMPLE 1
A commercially available silicone rubber for rubber switch (SE4706V manufactured by Toray Dow Corning Silicone Company) was compression molded at 200° C., and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength and 100% stress of the test piece were evaluated. The results are shown in Table 1.
COMPARATIVE EXAMPLE 2
A commercially available polyester elastomer/nylon elastomer composite for rubber switch ("GRILUX E-200" manufactured by Dainnipon Ink and Chemicals, Inc.) was injection molded at a cylinder temperature of 220° C. and metal mold temperature of 50° C., and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength and 100% stress of the test piece were evaluated. The results are shown in Table 1.
COMPARATIVE EXAMPLE 3
A commercially available thermoplastic polyurethane/nitrile rubber composite for rubber switch ("DYNAFLEX LU9008" manufactured by Japan Synthetic Rubber Co., Ltd.) was compression molded at 180° C. and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength and 100% stress of the test piece were evaluated. The results are shown in Table 1.
COMPARATIVE EXAMPLE 4
77 parts of PEA, 3 parts of 1,4-BG, and 20 parts of MDI were kneaded and polymerized for five minutes, by using the twin-shaft extruder, at a cylinder temperature of 210° C.
The obtained polyurethane polymer was injection molded at a cylinder temperature of 200° C. and metal mold temperature of 50° C., and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength and 100% stress of the test piece were evaluated. Its characteristics are shown in Table 1.
COMPARATIVE EXAMPLE 5
The IIR used in Example 1 was compression molded at 140° C., and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength and 100% stress of the test piece were evaluated. Its characteristics are shown in Table 1.
COMPARATIVE EXAMPLE 6
40 parts of polypropylene ("UBE POLYPRO J6709H" manufactured by Ube Industries, Ltd.), 46 parts of PEA, 2 parts of 1,4-BG, and 12 parts of MDI were kneaded for five minutes, by using the twin-shaft extruder, at a cylinder temperature of 180° C.
The obtained composite was injection molded at a cylinder temperature of 200° C. and die temperature of 50° C., and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength, 100% stress, and dispersibility of the test piece were evaluated. Its characteristics evaluation results are shown in Table 1.
COMPARATIVE EXAMPLE 7
40 parts of polyethylene ("ESPRENE E808" manufactured by Sumitomo Chemical Company, Limited), 46 parts of PEA, 2 parts of 1,4-BG, and 12 parts of MDI were kneaded for five minutes, by using the twin-shaft extruder, at a cylinder temperature of 180° C.
The obtained composite was injection molded at a cylinder temperature of 200° C. and die temperature of 50° C., and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength, 100% stress, and dispersibility of the test piece were evaluated. Its evaluation results are shown in Table 1.
COMPARATIVE EXAMPLE 8
40 parts of ethylene/propylene copolymer ("UBE POLYETHY F522" manufactured by Ube Industries, Ltd.), 46 parts of PEA, 2 parts of 1.4-BG, and 12 parts of MDI were kneaded for five minutes, by using the twin-shaft extruder, at a cylinder temperature of 180° C.
The obtained composite was injection molded at a cylinder temperature of 200° C. and metal mold temperature of 50° C., and a test piece was prepared. As in Example 1, the hardness, impact resilience, tensile strength, 100% stress, and dispersibility of the test piece were evaluated. Its characteristics are shown in Table 1.
TABLE 1__________________________________________________________________________ COMPARATIVE EXAMPLE EXAMPLE 1 2 3 4 1 2__________________________________________________________________________Mechanical propertiesHardness 58 70 60 73 60 84Impact resilience (%) 60 68 62 68 62 74Tensile strength (Kg/cm.sup.2) 90 140 100 140 90 150100% tensile stress (Kg/cm.sup.2) 25 40 27 35 25 50Injection molding property GOOD GOOD GOOD GOOD POOR GOODDispersibility (microns) 0.1 0.1 0.1 0.1 10 10__________________________________________________________________________ COMPARATIVE EXAMPLE 3 4 5 6 7 8__________________________________________________________________________Mechanical propertiesHardness 82 80 22 23* 82 98Impact resilience (%) 72 68 8 65 72 62Tensile strength (Kg/cm.sup.2) 280 430 30 350 150 230100% tensile stress (Kg/cm.sup.2) 52 40 9 120 48 80Injection molding property POOR GOOD POOR GOOD GOOD GOODDispersibility (microns) 10 10 10 10 10 10__________________________________________________________________________ *Value by JIS D
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A polymer composite comprises about 5 to 95 parts by weight of a copolymer (A) selected from the group consisting of olefin/diene copolymer and ethylene/(meth)acrylic acid ester copolymer, and 5 to 95 parts by weight of a polyurethane resin (B), wherein the polyurethane resin is one which is synthesized in the melted copolymer in the absence of a compatibilizer, a composition for molding comprising such polymer composite and electroconductive fillers and its molded article, and rubber contacts. The polymer composite possesses the flexibility and durability equivalent to those of silicone rubber, has excellent injection molding property, can be made by a short manufacturing process, and can be manufactured inexpensively. The polymer composite of the invention, when used together with an electroconductive filler, is effectively applied as rubber contacts, that is, flexible electric connection members of electric products.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electronic pattern sewing machine with a cloth feeding device including pulse motors, and more particularly to a temporary stop device for stopping the sewing machine during sewing.
2. Description of the Prior Art
The operation of a conventional electronic pattern sewing machine is controlled according to a sewing machine controlling program. Accordingly, the sewing machine suffers from the problem that the sewing machine is driven until the end of the pattern is reached and, even though the operater may want to stop the sewing machine immediately when the thread is cut, it is impossible to stop the sewing machine. Accordingly, no stitches are formed after the point where the thread has been cut, but holes are formed in the sewn article with the needle so that the sewn article becomes unsatisfactory as a product. Even if an attempt is made to trace the holes thus formed with the thread, it is considerably difficult to accurately position the sewn article back to the point where the thread has been cut. Thus, in practice, it is difficult to sew an article again.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of this invention is to provide a pattern sewing machine with is designed so that the sewing machine can be stopped during sewing and a cloth feeding device can be driven as desired, and so that, when the thread is cut during sewing, the sewing machine is stopped to reconnect the thread, so that sewing the pattern can be started according to the predetermined control program.
The foregoing object and other objects of the invention have been achieved by the provision of a pattern sewing machine according to the invention, which comprises: a cloth feeding mechanism driven by a first motor; a sewing machine mechanism driven by a second motor; a memory element in which control data are stored, the control data including pattern data for determining the direction and amount of rotation of the first motor; a control circuit for reading the control data, to synchronously drive the cloth feeding mechanism and the sewing machine mechanism; temporary stop instruction means for stopping the sewing machine mechanism during sewing; and minute movement instruction means for moving the cloth feeding mechanism only, the control circuit comprising: a first control element responsive to an instruction from the temporary stop instruction means for stopping a needle at a predetermined position and for stopping the cloth feeding mechanism; and a second control element for minutely moving, according to the data, the cloth feeding mechanism from a position where the cloth feeding mechanism has been stopped, and thereafter driving the sewing machine mechanism and cloth feeding mechanism according to the control data.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature, principle and utility of the invention will become more clear from the following detailed description and the appended claims when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram showing one preferred embodiment of this invention;
FIG. 2 is an explanatory diagram showing the arrangement of pattern data stored in a memory element in FIG. 1; and
FIGS. 3A-3C show a flow chart for a description of an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One preferred embodiment of this invention will now be described with reference to the accompanying drawings.
FIG. 1 shows a control device for a pattern sewing machine according to the invention. In FIG. 1, reference numeral 1 designates a CPU (central processing unit); 2, a memory element for storing pattern data and a cassette for protecting the memory element (hereinafter referred to as "a memory cassette 2", when applicable); 3, a RAM (random access memory); 4, a ROM (read-only memory) in which a control program for the entire sewing machine is stored; 5, an input port for reading and transferring all input data to the CPU; and 6, an output port for outputting output data from the CPU. The above-described circuit elements (1) through (6) form a microcomputer section.
Further in FIG. 1, reference numeral 21 designates a pulse oscillator for providing an output pulse. A cloth feeding device CF coupled to motors 18 and 19 by a linkage mechanism (not shown) is driven in synchronization with the oscillator pulse when the sewing machine is not rotated. Reference numeral 7 designates a circuit for frequency-dividing the output pulse of the pulse oscillator. As will be described in more detail below, the circuit 7 is used to provide a pulse which is used as a needle lower position signal when the machine is not in operation. (Circuit 7 will hereinafter be referred to as "a manual lower position circuit", when applicable). Reference numerals 8, 9, 22 and 23 designate AND circuits; 10 and 24, OR circuits; 11, a pattern sewing start switch; 12, a variable speed type main motor for driving the machine mechanism, the main motor 12 comprising a flywheel section (not shown) which rotates at all times, and a clutch brake section (not shown) for transmitting the rotation of the flywheel section to the sewing machine; 13, a main motor control circuit for controlling the clutch brake, either to rotate the main motor at a constant speed or for stopping the main motor at a predetermined position; 14, the sewing machine; 15, a detector for detecting the sewing machine's needle position and for detecting the number of revolutions per minute of the sewing machine; 16, a thread cutting device; 18, an X-direction driving pulse motor for the cloth feeding device; 19, a Y-direction driving pulse motor, the pulse motors 18 and 19 driving the cloth feeding device through a well-known belt or rack-and-pinion device by which the rotational movement of the pulse motors is converted to linear movement, to move the cloth as desired, to thereby sew a desired patter; and 20, a cloth retaining device for operating a clamping portion 20 a of the feeding device for holding a piece of cloth in the cloth feeding device.
Further in FIG. 1, reference numeral 17 designates a pulse motor drive circuit in which pulse motor driving data are received in parallel from the output port 6 and are converted into a sewing machine rotation signal and series data synchronous with the signal from the pulse oscillator 21, to drive the pulse motors 18 and 19; 25, a temporary stop switch; 26, a positive-direction minute movement switch; and 27, a negative-direction minute movement switch.
Two kinds of pattern data are stored in the memory cassette 2, i.e. X-direction drive data and Y-direction drive data as shown in FIG. 2, each of which is made up of eight (8) bits. The bits X 0 through X 4 , and Y 0 through Y 4 provide data concerning the amount of feed (or rotation). The bits X 5 , X 6 , Y 5 and Y 6 provide sewing machine control data, and bits X 7 and Y 7 provide feed direction (or rotation direction) data. The sewing machine control data (X 5 , X 6 , Y 5 , Y 6 ) include four data indicating sewing starting (motor starting), thread cutting, idle feeding and sewing ending.
The operation of the pattern sewing machine according to the invention will be described with reference to FIG. 3 which shows a flow chart showing the sequence of operation of the pattern sewing machine.
Upon operation of the power switch, the CPU 1 begins performing control according to data from the ROM 4 in which the controlling program has been stored. First, the CPU 1 carries out the initial reset operation in subroutine 100, to thereby place all the parts of the microcomputer section in an initial state. Then, initial state data are outputted from the output port 6 in step 102, so that the other control sections are placed in an initial reset state. Next, input data (e.g. a start signal and a needle position signal) are read through the input port 5 in step 104. Since the temporary stop switch 25 has not been activated, and with the Stop Flag STOPF in a reset state, the program is followed through steps 106 and 108 to step 110 in FIG. 3, and a signal from the output port 6 is applied to the AND circuit 9 so that the output signal of the manual lower position circuit 7 is applied to the input port 5 through OR gate 10. The detection of the moment when the lower position signal is generated (both for "manual" and "auto") is indicated at step 110 in FIG. 3. For the automatic operation, the detector 15 is so adjusted that, when the sewing machine is rotated, the lower position signal is produced at the instant when the needle is removed from the cloth. Accordingly, the detector 15 is used to enable the operation of the cloth feeding device after removal of the needle from the cloth.
When the lower position signal is detected at step 110, and since the Auto Flag AUTOF has not yet been set, the flow chart is followed through step 112 to step 114. The previous depression of the start switch will have resulted in the application of a start signal through the input port 5. This start signal will be detected at step 114, and the cloth retainer of the cloth retaining device 20 will then hold the cloth at the time instant when the lower position signal is produced. Under this condition, in subroutine 116, a pattern data top address, or starting address, is determined from the memory cassette 2 in which the data of a pattern to be sewn have been stored. Then, an Auto Flag AUTOF is set in step 120. After the AUTOF has been set, control is returned to the top of the flow chart. Thus, the determination of the pattern data top address is performed only once after the depression of the start switch. Thereafter, upon the occurrence of the next manual lower position signal detected at step 110, the set condition of the AUTOF will be detected at step 112 so that the data in the top address will be read at step 122. The data in this case is the eight bits of X data in FIG. 2, with the Y data being stored in the next address in the memory cassette 2. The X and Y data are alternately stored in consecutive addresses. The starting of the sewing operation or the starting of the idle feeding operation for driving only the cloth feeding device are determined from the data in the bits X 5 and X 6 of the X data. For instance, when the first eight bits of X data are transferred to the RAM at step 122, the bits X 5 and X 6 are examined. If the starting of the sewing operation is indicated by bits X 5 and X 6 , this will be detected at step 124, and the motor starting process is carried out in subroutine 126. The clock signal is then switched over to automatic, whereby a signal from output port 6 will enable AND gate 8 so that the rotation signal from the detector 15 of the sewing machine 14 will be provided through gate 8 and OR gate 10 as an automatic clock signal to the input port 5. The data address is then advanced by one address increment at step 128 so that the Y data occupying the next address location in the memory cassette 2 will be transferred to the RAM at step 130. The address is then further incremented by one address at step 132, and the program returns to the top of the flow chart of FIG. 3.
Thereafter, the X data and Y data stored in the RAM 3 are outputted through the output port 6 in step 102 and transferred to the pulse motor drive circuit 17. At the same time, the rotation of the sewing machine results in the application of a sewing machine rotation pulse to the circuit 17 through the AND circuit 23 and the OR circuit 24. As a result, the circuit 17 generates a pulse motor drive pulse in synchronization with the rotation of the sewing machine, whereby the pulse motors 18 and 19 are rotated according to the pattern data.
The sewing operation is started as described above. When ending data and thread cutting data are included, after the thread has been cut, the needle is stopped, and the cloth retainer of the cloth retaining device 20 is lifted to release the cloth. When the sewing machine 14 is stopped, no sewing machine rotation pulse is provided by the detector 15. Therefore, the "auto" clock is switched over to the "manual" clock by disabling gate 8 and enabling gate 9 so that the control circuit is operated in accordance with the output pulse of the oscillator 21.
It is assumed that the thread is cut during sewing. In this case, when the temporary stop switch 25 is operated, the temporary stop data is read through the input port 5 and a STOPF is set. The STOPF can be set only when the AUTOF haes been set. That is, if a sewing operation has been ended and the sewing machine 14 is not in operation, it is unnecessary to receive the temporary stop data even if the temporary stop switch is operated, since the temporary stop is unimportant. Thus, with the AUTOF reset, and the temporary stop is ignored.
Assuming there is no step data and that the AUTOF remains set, the set condition of the STOPF is detected at step 108 and a procedure for stopping the sewing machine with the needle set at the upper position is carried out by switching from the "auto" clock to the "manual" clock at step 135 and then iteratively performing subroutine 136 and decision step 138. The position of the cloth feeding device when the sewing machine is stopped with the needle set at the upper position by operating the temporary stop switch 25 is often beyond the position where the thread has been cut, and the pattern data will also have advanced. In this case, the negative-direction minute movement switch 27 is depressed. The depressed condition of the negative-direction minute movement switch 27 will be detected at step 140, and when the next manual lower position signal is provided through AND gate 9 and detected at step 142, the address data will be succesively decremented while reading out the Y and X data in steps 144-150, and the cloth feeding device will be moved backwardly in accordance with the pattern data when each manual lower position signal is produced.
The address of the pattern data has been advanced by one address in the sewing operation. Accordingly, when the sewing machine is stopped temporarily, the address is for the next data, namely, the X data. Therefore, by turning back the address by one address, the Y data used before the sewing machine is stopped is read and stored in the RAM 3. In this operation, the feed direction data in the Y data is reversed. Next, by further turning back the address by one address, the X data, with its direction of feed reversed, is stored in the RAM 3. Next, by outputting the contents of the RAM 3, data opposite to the pattern data outputted immediately before the temporary stop is outputted, whereby the cloth feeding device moves back to the step position according to the pattern data. This operation is continued in synchronization with the output pulse of the pulse oscillator 21 while the negative-direction minute movement switch 27 is kept depressed, and the cloth feeding device is stopped when the switch 27 is released. Similarly, by operating the positive-direction minute movement switch 26, the cloth feeding device is moved in accordance with steps 152-162 to advance the pattern according to the pattern data. When the cloth feeding device has been moved from the thread-cutting location to a desired point, the start switch 11 is depressed and the STOPF is reset in step 166 after detection of the start signal at step 164. Accordingly, the control is returned to the ordinary sewing routine instead of the minute movement routine. Thereafter, the same control as that in the ordinary sewing operation is carried out, and no further description thereof is believed to be necessary.
In the above-described embodiment, the temporary stop switch 25 is manually operated. However, if the switch is replaced by a switch which automatically detects when the thread is cut, then the sewing machine can be stopped automatically immediately when the thread is cut.
As is apparent from the above description, according to the invention, when the thread is cut during sewing, the sewing machine can be stopped temporarily, the cloth feeding device can be moved minutely, and the sewing can then be resumed. Accordingly, in the case where the sewing pattern is intricate and involves a large number of stitches, the amount of labor with the pattern sewing machine according to the invention is much less than that with the conventional pattern sewing machine wherein the sewing would have to be begun all over again. If a sewn article is of thick leather or the like and it is sewn with the thread cut, then holes are formed in the article with the needle, and in this case it is impossible to sew the article again. However, according to the invention, the frequency of occurrence of such unsatisfactory sewn articles can be reduced.
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A pattern sewing machine comprises a cloth feeding mechanism for moving a piece of cloth; a sewing machine mechanism driven independently of the cloth feeding mechanism; a memory element in which control data including pattern data and sewing machine drive data are stored; a control circuit for synchronously driving the cloth feeding mechanism and the sewing machine mechanism according to the control data stored in the memory element; a temporary stop instruction for stopping the sewing machine mechanism during sewing; and a minute movement instruction for driving the cloth feeding mechanism only, the control circuit having a function of driving the cloth feeding mechanism according to the minute movement instruction after the cloth feeding mechanism has been stopped by the temporary stop instruction, and a function of driving the cloth feeding mechanism according to the pattern data thereafter.
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FIELD OF THE INVENTION
The present invention relates to guitars, and more particularly to a guitar that has a sound box that has been modified to allow for a more stable guitar position on the body while playing.
BACKGROUND OF THE INVENTION
Guitars are traditionally played in a variety of positions including standing and sitting positions. Traditionally straps have been used to help keep the guitar in a stable position on the body while playing. In the standing position, the use of guitar straps is indeed effective in keeping the guitar in a stable position on the body and is still the most frequently used method today. However, in the sitting position, the use of guitar straps is far less effective at keeping the guitar stable for several reasons. One reason is that in the sitting position a strapped guitar is being supported both from the neck and on the thigh of the instrumentalist. While playing the guitar in the sitting position many instrumentalists shift their body weight around which can sometimes cause the guitar to shift out of position. Since the sitting strapped guitar is supported from two independent areas of the body which can move independently during play, this can cause many points during play where the guitar may not be in the optimum playing location for the instrumentalist.
Yet another example of why the strapped guitar is not ideal in the sitting position is due to the irritation caused from the guitar strap at the surfaces where it is in contact with the neck of the instrumentalist. This irritation can come from different material properties of the guitar strap such as the amount of friction it has on human skin as well as possible adverse skin reactions with the strap fabric on some instrumentalist.
A third example is due to the design of the sound box of the guitar itself. Most guitar manufacturers still use traditional figure eight style shapes with either square edges or only slightly radiused corners. When these corners rest against the curved thigh of the instrumentalist, there is very little surface area to grip to the instrumentalist and frequently the instrumentalist compensates for concerns of the guitar slipping down the thigh by keeping their neck taught against the guitar strap. During extended periods of play this can cause a fair amount of discomfort to the instrumentalist, and over many years of play may even contribute to neck and upper back pain requiring regular chiropractic therapy.
Clearly, there is a need to improve the design of the sound box of the guitar itself to provide a better alternative to the old method of using guitar straps. It is the objective of the present invention to improve upon the design of the guitar sound box in order to allow the modern instrumentalist to play the guitar in all common forms of sitting positions without the use of guitar straps.
There have been a few limited attempts in the prior art to make ergonomic improvements to the guitar sound box. U.S. Pat. No. 7,169,991 Guitar issued to Ralbovsky in 2007 discloses a contoured concave pocket shape along the upper half of the backside of the guitar sound box to prevent discomfort and unwanted compression of the guitar against the breast of female instrumentalist while playing. Although Ralbovsky's invention would effectively address this problem with female instrumentalist, it certainly does not provide any extra stability to the guitar while playing in the sitting position and would be of no benefit to male instrumentalists.
U.S. Pat. No. 7,183,473 Ergonomic Stringed Instrument and Ergonomic Roundback Guitar issued to Untermyer et al in 2007 discloses a complex contoured curved three dimensional shape on the entire backside of the guitar sound box. Although Untermyer's invention does provide ergonomic advantages over the traditional guitar sound box for the instrumentalist, it does not offer any ability to increase stability while resting on the thigh and due to its smooth curvature may actually tend to slip on the thigh even more than the guitar sound box of prior art.
Finally, U.S. Pat. No. 7,449,624 Ergonomic Classical Guitar issued to Boute in 2008 discloses a sound box with two truncated pockets to help the instrumentalist during playing in both the classical and standard sitting positions. Although Boute's improvements do offer some degree of improvement over the guitars of prior art, the truncated portions are substantially 45 degree planar chamfered shapes and they do not contour around the convex curvature of the thigh of the instrumentalist. Furthermore, there is no mention of adding any means to increase gripping friction on the planar shapes in Boute's invention and therefore Boute's guitar would most likely still require additional supporting means such as the traditional guitar strap to prevent the guitar sound box from slipping down on the thigh during play.
Clearly, the ergonomic guitar inventions of prior art as evidenced by these examples do not provide a fully stabilized guitar while playing in the sitting positions and would all require the use of guitar straps to prevent slippage on the thigh during play. It is the object of the present invention to disclose several embodiments of a novel guitar sound box that has a contoured concave pocket shape to provide ergonomic improvements in various sitting positions as well as an optional capability to increase gripping power against the thigh by using an attached gripping pad.
BRIEF SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide an ergonomic guitar with a contoured rest pocket available in various configurations that will allow the instrumentalist to play in the sitting position without the need for wearing a guitar strap.
It is yet another object of the present invention to provide an optional gripping pad that has a contoured shape to fit into the contoured rest pocket to provide additional gripping power to further increase stability while playing in any sitting position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the classic sitting position.
FIG. 2 is a side view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the classic sitting position.
FIG. 3 is a back view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the classic sitting position.
FIG. 4 is a perspective view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the classic sitting position.
FIG. 4 a is a detailed perspective view of the ergonomic guitar classical sound box rest pocket with an optional gripping pad.
FIG. 5 is a view showing the use of the ergonomic guitar with a classical sound box rest pocket.
FIG. 6 is a front view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the standard sitting position.
FIG. 7 is a side view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the standard sitting position.
FIG. 8 is a back view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the standard sitting position.
FIG. 9 is a perspective view of the ergonomic guitar with a sound box rest pocket located to provide better stability to the instrumentalist while playing the standard sitting position.
FIG. 9 a is a detailed perspective view of the ergonomic guitar standard sound box rest pocket with an optional gripping pad.
FIG. 10 is a view showing the use of the ergonomic guitar with a standard sound box rest pocket.
FIG. 11 is a front view of the ergonomic guitar showing a half standard sound box rest pocket that is located to provide better stability to the instrumentalist while playing in the standard sitting position.
FIG. 12 is a side view of the ergonomic guitar with a half standard sound box rest pocket located to provide better stability to the instrumentalist while playing the standard sitting position.
FIG. 13 is a back view of the ergonomic guitar with a half standard sound box rest pocket located to provide better stability to the instrumentalist while playing the standard sitting position.
FIG. 14 is a perspective view of the ergonomic guitar with a half standard sound box rest pocket located to provide better stability to the instrumentalist while playing the standard sitting position.
FIG. 14 a is a detailed perspective view of the ergonomic guitar alternative half standard sound box rest pocket with an optional gripping pad.
FIG. 15 is a view showing the use of the ergonomic guitar with a half standard sound box rest pocket.
FIG. 16 a is a perspective top view of an electric guitar with a half standard sound box rest pocket located for use in the standard sitting position.
FIG. 16 b is a perspective underside view of an electric guitar with a half standard sound box rest pocket located for use in the standard sitting position.
FIG. 16 c is a detailed perspective view of the half standard position sound box rest pocket for an electric guitar with an optional gripping pad.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and in particular FIGS. 1 through 5 , an acoustic guitar is designated by reference number 10 . In a primary embodiment, a concave shaped pocket 15 is located on the sound box at the location shown. In this first embodiment, the location of the pocket 15 as shown in FIG. 1 is intended for the instrumentalist to rest said pocket 15 against his thigh while playing in the classical sitting position. It should be noted that all of the drawings shown in this specification are drawn for right-handed guitar players. For left-handed players, the sound box rest pockets would be located on the opposite side as shown in these drawings. Referring next to FIG. 2 , the full shape of the classical sound box rest pocket 15 is shown as looking at the guitar 10 on the right side.
It is intended that a variety of curved concave shapes are possible to create said classical rest pocket 15 such as parabolic or arcuate geometries. The top apex of the curve in the preferred embodiment is located below the front face of the sound box by approximately ¼ to ½ inch. Referring next to FIGS. 3 and 4 , the classical sound box pocket 15 is shown in the back and perspective views so that the concave curvature shape can be seen. This concave shape of the pocket provides a contoured fit on the upper thigh of the instrumentalist and keeps the guitar in a stable position without the need for wearing guitar straps. An alternative embodiment of the classical rest pocket 15 is shown in FIG. 4 a where a thin gripping pad 20 is shown attached to said rest pocket 15 . In the preferred embodiment, the gripping pad is made of a resilient material such as neoprene rubber and may have a textured surface as shown in order to increase the gripping power of the pad. Various means are possible to attach the gripping pad to the sound box rest pocket such as pressure sensitive adhesives. The thickness of the gripping pad in the preferred embodiment may be between 1/32 and 3/16 of an inch. The gripping pad 20 would be cut such that it fits inside the perimeter of the sound box rest pocket as shown in FIG. 4 a.
Referring now to FIG. 5 , the intended use of the guitar with classical sound box rest pocket 15 is shown in the classical sitting position as represented by a right-handed instrumentalist 100 . The concave shape of the rest pocket 15 fits over the upper right thigh 105 and creates a comfortable yet stable playing position.
Referring next to FIGS. 6 through 10 , an acoustic guitar is again designated by reference number 10 . In a secondary embodiment, a concave shaped pocket 25 is located on the sound box at a position further up along the sound box as shown in FIG. 6 . In this second embodiment, the location of the pocket 25 is intended for the instrumentalist to rest said pocket 25 against his thigh while playing in the standard sitting position. Referring next to FIG. 7 , the full shape of the standard sound box rest pocket 25 is shown as looking at the guitar 10 on the right side.
It is intended that a variety of curved concave shapes are possible to create said standard rest pocket 25 such as parabolic or arcuate geometries. The top apex of the curve in the preferred embodiment is located below the front face of the sound box by approximately ¼ to ½ inch. Referring next to FIGS. 8 and 9 , the standard position sound box pocket 25 is shown in the back and perspective views so that the concave curvature shape can be seen. This concave shape of the pocket provides a contoured fit on the upper thigh of the instrumentalist and keeps the guitar in a stable position without the need for wearing guitar straps. An alternative embodiment of the standard rest pocket 25 is shown in FIG. 9 a where a thin gripping pad 20 is shown attached to said rest pocket 25 . In the preferred embodiment, the gripping pad is made of a resilient material such as neoprene rubber and may have a textured surface as shown in order to increase the gripping power of the pad. Various means are possible to attach the gripping pad to the sound box rest pocket such as pressure sensitive adhesives. The thickness of the gripping pad in the preferred embodiment may be between 1/32 and 3/16 of an inch. The gripping pad 20 would be cut such that it fits inside the perimeter of the standard sound box rest pocket as shown in FIG. 9 a.
Referring now to FIG. 10 , the intended use of the guitar with standard sound box rest pocket 25 is shown in the standard sitting position as represented by a right-handed instrumentalist 100 . The concave shape of the rest pocket 25 fits over the upper right thigh 105 and creates a comfortable yet stable playing position. In the standard playing position, the orientation of the guitar is approximately parallel with the ground, and this is why the location of said standard sound box pocket 25 has shifted higher up on the guitar 10 as compared with the aforementioned classical playing position.
Referring next to FIGS. 11 through 15 , an acoustic guitar is again designated by reference number 10 . In this third embodiment, a concave shaped pocket 35 is also provided for use in the standard sitting position and the location on the sound box is shown in FIG. 11 . FIG. 12 shows the side view of the guitar 10 and in this view it can be seen that the apex of the pocket curvature starts at approximately half of the thickness of the guitar sound box. This allows the instrumentalist to not only further tilt the guitar sound box towards his chest while sitting in the standard position, but also allows the instrumentalist a greater degree of flexibility in playing positions by allowing movement of the guitar further forward on the thigh towards the knee without losing gripping surface.
It is intended that a variety of curved concave shapes are possible to create said standard rest pocket 35 such as parabolic or circular geometries. Referring next to FIGS. 13 and 14 , the half standard position sound box pocket 35 is shown in the back and perspective views so that the concave curvature shape can be seen. This concave shape of the pocket provides a contoured fit on the curved upper thigh of the instrumentalist and keeps the guitar in a stable position without the need for wearing guitar straps. An alternative embodiment of the half standard rest pocket 35 is shown in FIG. 14 a where a thin gripping pad 20 is shown attached to said half standard rest pocket 35 . In the preferred embodiment, the gripping pad is made of a resilient material such as neoprene rubber and may have a textured surface as shown in order to increase the gripping power of the pad. Various means are possible to attach the gripping pad to the sound box rest pocket such as pressure sensitive adhesives. The thickness of the gripping pad in the preferred embodiment may be between 1/32 and 3/16 of an inch. The gripping pad 20 would be cut such that it fits inside the perimeter of the sound box rest pocket as shown in FIG. 14 a.
Referring now to FIG. 15 , the intended use of the guitar with the half standard sound box rest pocket 35 is shown in the standard sitting position as represented by a right-handed instrumentalist 100 . The concave shape of the rest pocket 35 fits over the upper right thigh 105 and creates a comfortable yet stable playing position. It should be noted that in this embodiment, the orientation of the guitar 10 is still approximately parallel with the ground except the sound box of the guitar has been tilted slightly upwards towards the face of the instrumentalist. The movement of the apex of the curvature to start at approximately half of the distance of the sound box provides this additional degree of tilt while still creating a stable guitar playing position for the instrumentalist. Furthermore, the movement of the apex in the half standard rest pocket position provides a greater degree of flexibility in playing positions by allowing movement of the guitar further forward on the thigh towards the knee without losing gripping surface.
Although the embodiments of the present invention have thus far been shown only in acoustic guitar applications, the contoured rest pocket can be applied to other stringed instruments including electric guitars. FIGS. 16 a and 16 b show a fourth embodiment of the present invention where the sound box of an electric guitar 12 is modified to include a half standard sound box rest pocket 35 . In yet another embodiment as shown in FIG. 16 c , an optional gripping pad 20 is shown attached to the half standard sound box pocket 35 of said electric guitar 12 .
Another advantage of the present invention is that the modifications to the sound box as discussed in these aforementioned embodiments do not have any adverse effects on the quality of the sound produced since the sound board itself is not compromised in any of the aforementioned sound box pocket embodiments. During future production of ergonomic guitars having any combination of stabilized sound box rest pockets 15 , 25 or 35 , the sound quality of the guitar can be measured using current sound measurement techniques as part of quality control release testing to verify that the ergonomic guitar meets quality control specifications based on the sound from a reference guitar without sound box rest pockets.
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The sound box of a guitar is modified to add a concave shaped pocket that can be placed at various locations along the sound box body in order to be used to rest against the thigh of the instrumentalist while in the sitting position. An optional rubber gripping pad can be attached to the sound box rest pocket to add additional gripping power if desired. The sound box rest pocket can be applied to both electric and acoustic guitars and eliminates the need to wear guitar straps when playing in the sitting position. The sound box rest pocket does not negatively affect the quality of the sound produced from the guitar.
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TECHNICAL FIELD
The present disclosure relates generally to a surgical cross connecting apparatus for use with implantation rods.
BACKGROUND
The spinal column is a highly complex interconnection of individual bones coupled together to provide, among other things, protection of the nervous system, while also enabling collective movements in a plurality of directions.
Due to various genetic and/or developmental occurrences, including diseases, developmental irregularities, trauma, stress, and the like, the spinal column may require surgical intervention. To protect and/or aid in the recovery of a surgically repaired section of the spinal column, there are often situations wherein it is desirable to collectively restrict movement of one or more bones of the spinal column.
Immobilization of a section of the spinal column may be achieved using a variety of known surgically implanted support systems and methods, such as use of posterior surgical implants comprising one or more implantation rods. In general, a surgically-implanted rod is fixedly attached by first threading one or more anchor screws to a pedicle of one or more vertebrae of the spinal column. Each anchor screw is in turn fixedly coupled to the implantation rod at proximate locations along its shaft.
In certain patients, it may be desirable to increase the support and torsional rigidity of the surgically-implanted implantation rod system. These situations may require not only support on the side of the spinal column that is attached to an implantation rod, but also torsional rigidity and support collectively between the implantation rods. To achieve this, patients have been selectively provided with surgically implanted cross connector systems to couple between two implantation rods.
SUMMARY
Conventional screw head-type cross connector systems, such as those that secure two implantation rods by attaching to the head of anchor screws (see U.S. Pat. No. 7,717,939), and hook set-type cross connector systems, such as those that secure two implantation rods by attaching hooks to the shaft of the rod (see U.S. Pat. No. 6,238,396), may be employed to couple two implanted rods in situations wherein the implantation rods are substantially parallel relative to each other in every axis (hereinafter “three dimensionally parallel” or “3D parallel”) and have a sufficient separation distance between each other. An example of a pair of implantation rods that are three dimensionally parallel is shown in FIG. 1 , wherein d represents a minimum separation distance between a first implantation rod ( 100 ) and a second implantation rod ( 200 ) so as to enable a conventional cross connector system to attach between the two implantation rods.
Due to their limited adjustability, including providing limited screw head to screw head length adjustments, conventional screw head-type cross connector systems are generally not suitable for situations where the implantation rods are not three dimensionally parallel and/or there is insufficient separation distance between screw heads (hereinafter “non-ideal situations” or “non-ideal positions”). An example of two implantation rods ( 100 , 200 ) that are not three-dimensionally parallel is shown in FIG. 2 . Conventional hook set-type cross connector systems have been recently introduced to provide a certain degree of freedom to accommodate more non-ideal situations, particularly those where conventional screw head-type cross connector systems cannot be employed. However, they too have limitations in use, particularly in those situations requiring more degrees of freedom to cross connect in non-ideal situations and/or having insufficient separation distance between screw heads.
In general, non-ideal situations frequently occur in patients requiring increased support and torsional rigidity between sets of bones supported by implantation rods. Because conventional cross connector systems are best suited for attaching in substantially ideal situations and certain limited non-ideal situations, as described earlier, surgeons are more often than not faced with having to perform complicated surgical re-adjustments of the already-implanted implantation rod systems to accommodate the attaching of conventional cross connectors. Surgical re-adjustments may include removing hooks, anchor screws, coupling components, and/or implantation rods, and re-threading the anchor screws and/or re-installing the components in a different location/position/orientation, so as to enable the implantation rods to be substantially three-dimensionally parallel and/or having sufficient separation distance between the screw heads.
In practice, surgeons are often faced with practical problems and difficulties in implanting implantation rods in patients to be substantially three-dimensionally parallel and having sufficient separation distance due to, among other things, the anatomically varying sizes/shapes/orientations of the spinal column and/or the varying degrees and/or nature of surgical repairs required and/or rendered to the spinal column of each particular patient. More often than not, surgeons have little choice other than to implant implantation rods in non-ideal positions relative to each other. This in turn makes it difficult to properly couple conventional cross-connecting systems to such implanted implantation rods, and surgeons are often required to perform complicated surgical re-adjustments of the implanted rods and/or anchor screws to accommodate the conventional cross connector. In general, a tremendous amount of time, planning, effort, precision, and costs are incurred since these tasks typically involve, among other things, surgically removing one or more anchor screws, coupling components, and/or implantation rods, and surgically re-installing them in such a way as to properly accommodate a substantially ideal position of the implantation rods, as required by conventional cross connecting systems.
In considering the above problems, it is recognized herein that providing increased support and torsional rigidity between implantation rods that are implanted in non-ideal positions can be achieved without the need to perform surgical re-adjustments of the implanted implantation rods, coupling components, and/or anchor screws.
Present example embodiments relate generally to an apparatus operable to couple a pair of implantation rods. Each implantation rod is secured by at least two fastener elements having a head. The apparatus comprises at least one main assembly, said main assembly operable to move relative to a head of one of the fastener elements when not in a locked position. The apparatus also comprises a center link extending in an axial direction, said center link operable to move relative to the main assembly when not in a locked position. The main assembly is operable to receive the center link and a head of one of the fastener elements and secure the center link and the head relative to the main assembly when in a locked position.
In accordance with another example embodiment, an apparatus is operable to fixably couple a pair of implantation rods, wherein each implantation rod is secured by at least two fastener elements. The apparatus comprises a center link extending in an axial direction and two or more main assemblies. Each main assembly is operable to receive the center link and a head of one of the fastener elements when not in a locked position. Each main assembly comprises a main body, a center link clamp having an adjustable bore and housed within the main body, an outer sleeve surrounding at least a portion of the main body, an anchor clamp having an adjustable portion and proximate to the main body and the outer sleeve, and an adjustment member operable in cooperation with the main body to adjust the adjustable bore and the adjustable portion. The center link is received in the adjustable bore of the center link clamp and the head is received in the adjustable portion of the anchor clamp. The center link and the head are securable relative to the main body when the adjustment member is actuated into a locked position. Furthermore, the center link is movable relative to the main body and the adjustable portion is movable relative to each main body when the adjustment member is actuated from the locked position.
In another exemplary embodiment, an apparatus is operable to couple an implantation rod to a center link, wherein the implantation rod is secured by at least two fastener elements having a head. The apparatus comprises a main body, a center link clamp having an adjustable bore and housed within the main body, an outer sleeve surrounding at least a portion of the main body, an anchor clamp having an adjustable portion and proximate to the main body and the outer sleeve, and an adjustment member operable in cooperation with the main body to adjust the adjustable bore and the adjustable portion.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and:
FIG. 1 is an example illustration of a pair of implantation rods that are three-dimensionally parallel;
FIG. 2 is an example illustration of a pair of implantation rods that are not three-dimensionally parallel;
FIG. 3A is a perspective view of an example embodiment of a cross connector;
FIG. 3B is an exploded view of an example embodiment of a cross connector;
FIG. 3C is a perspective view of an example embodiment of a cross connector coupled to a pair of implantation rods;
FIG. 4A is a perspective view of another example embodiment of a cross connector;
FIG. 4B is an exploded view of another example embodiment of a cross connector;
FIG. 4C is a perspective view of another example embodiment of a cross connector coupled to a pair of implantation rods;
FIG. 5A is a top view of an example embodiment of a cross connector illustrating a pivoting movement of the center link relative to the first and second main assemblies;
FIG. 5B is a top view of an example embodiment of a cross connector illustrating another pivoting movement of the center link relative to the first and second main assemblies;
FIG. 6 is a cross sectional view of an example embodiment of a cross connector having a set screw.
Although similar reference numbers may be used to refer to similar elements for convenience, it can be appreciated that each of the various example embodiments may be considered to be distinct variations.
DETAILED DESCRIPTION
The present invention will now be described hereinafter with reference to the accompanying drawings, which form a part hereof, and which illustrate example embodiments by which the invention may be practiced. As used in the disclosures and the appended claims, the term “example embodiment” does not necessarily refer to a single embodiment, although it may, and various example embodiments may be readily combined and interchanged, without departing from the scope or spirit of the present invention. Furthermore, the terminology as used herein is for the purpose of describing example embodiments only and is not intended to be a limitation of the invention. In this respect, as used herein, the term “in” may include “in” and “on”, and the terms “a”, “an” and “the” may include singular and plural references. Furthermore, as used herein, the term “by” may also mean “from”, depending on the context. Furthermore, as used herein, the term “if” may also mean “when” or “upon”, depending on the context. Furthermore, as used herein, the words “and/or” may refer to and encompass any and all possible combinations of one or more of the associated listed items.
Spinal fixation of an implantation rod may be provided by one or more fastener elements, such as an anchor screw, having a head. Typically, one or more anchor screws will be fixedly installed to a pedicle of one or more vertebrae, and correspondingly fixedly coupled about proximate sections of the shaft of the implantation rod. In many situations, a cross connector apparatus may be applied between two implanted implantation rods, particularly when enhanced support and torsional rigidity is required. Hereinafter, an “implanted anchor screw” will refer to an anchor screw that has already been fixedly installed to a vertebra and an “implanted implantation rod” will refer to an implantation rod that has already been fixedly coupled to one or more implanted anchor screws.
Reference is now made to an example embodiment of the cross connector ( 300 ) illustrated in FIGS. 3A , 3 B and 3 C. As shown in FIG. 3A , The cross connector ( 300 ) comprises a first main assembly ( 310 ), a second main assembly ( 320 ), and a center link ( 330 ) in communication with the first main assembly ( 310 ) and the second main assembly ( 320 ). The first main assembly ( 310 ) may be substantially the same as, and/or a mirror reflection of, the second main assembly ( 320 ), although they may also comprise one or more aspects that are oriented, positioned and/or operated differently so as to accommodate specific implanted anchor screw and implantation rod arrangements. In other words, example embodiments of the cross connector ( 300 ) are adaptively adjustable so as to attach in a wide range of non-ideal situations and positions to two or more implanted implantation rods. An example embodiment of the cross connector ( 300 ) attached to a set of implanted anchor screws and implantation rods is depicted in FIG. 3C .
As shown in FIG. 3B , each of the main assemblies ( 310 , 320 ) comprise a main body ( 311 , 321 ), an anchor clamp ( 312 , 322 ) having a fixably adjustable clamp portion ( 312 c , 322 c ) for receiving the head ( 351 ) of an anchor screw ( 350 ), a center link clamp ( 314 , 324 ) having an adjustable bore ( 314 a , 324 a ) for receiving the center link ( 330 ), an outer sleeve ( 313 , 323 ) surrounding at least a portion of the main body ( 311 , 321 ) housing the center link clamp ( 314 , 324 ), and a set cam assembly ( 315 , 325 ) comprising a set cam ( 315 a , 325 a ) and a set cam mating element ( 315 b , 325 b ) for enabling each main assembly ( 310 , 320 ) to be brought into and released from a locked position. The center link ( 330 ) is preferably an elongated symmetrically-shaped member receivable by the first and second main assemblies ( 310 , 320 ) in the adjustable bores ( 314 a , 324 a ) of their respective center link clamps ( 314 , 324 ), and may include one or more center link nubs ( 331 , 332 ) to restrict the main assemblies ( 310 , 320 ) from separating from the center link ( 330 ) when not in the locked position. The center link ( 330 ) may also take other shapes and forms in other example embodiments, such as elliptical, hexagonal, or other shapes, and may be straight as depicted or curved. It is to be understood by those skilled in the art that actuating to and releasing from a locked position can be achievable in a variety of ways, including the use of a set screw, or the like. An example embodiment of a cross connector ( 400 ) being provided with set screws ( 415 , 425 ) is illustrated in FIGS. 4A , 4 B and 4 C. Hereinafter, example embodiments of the cross connector will be described with reference to the cross connector ( 300 ) having set cams ( 315 , 325 ) of FIGS. 3A , 3 B and 3 C, although the descriptions will also be equally applicable to example embodiments of the cross connector ( 400 ) that are provided with set screws ( 415 , 425 ), and the like.
With reference to FIG. 3C , and for the purpose of illustrating exemplary ways in which an example embodiment of the cross connector may be practiced, certain imaginary axes will be hereinafter defined for the first main assembly ( 310 ) attached to a certain anchor screw ( 350 ) of a certain implantation rod ( 390 ). It is to be understood that the following discussion of movements of the first main assembly ( 310 ) and center link ( 330 ) are also applicable to other applications and situations, such as the first main assembly ( 310 ) attaching to any other anchor screw of any other implantation rod that may or may not be in the same orientation as depicted in the drawings, as well as to the second main assembly ( 320 ) being attached to any anchor screw of any other implantation rod that may or may not be in the same orientation as depicted in the drawings. Hereinafter, the imaginary axis drawn through the axial center of the anchor screw body ( 350 ) will be referred to as the “anchor screw axis” and is labeled as axis D. Furthermore, the imaginary axis drawn through the axial center of the implanted implantation rod ( 390 ) will be referred to as the “implantation rod axis” and is labeled as axis A. Furthermore, the imaginary axis drawn through the axial center of the main body ( 311 ) will be referred to as the “main body axis” and is labeled as axis E. Furthermore, an imaginary axis drawn through the axial center of the center link ( 330 ) will be referred to as the “center link axis” and is labeled as axis C.
When not in the locked position, an example embodiment of the cross connector is provided with a wide degree of freedom of movement about the implantation rod axis A, the anchor screw axis D, the main body axis E, and/or the center link axis C, which enables the cross connector to be adaptively applied between two or more anchor screw heads coupled to implantation rods that may or may not be three-dimensionally parallel and/or may or may not have sufficient separation distance, as required by conventional cross connector systems.
With reference to the axes depicted in FIG. 3C , in an exemplary non-ideal situation, the implanted orientation of one or more implanted anchor screws ( 350 , 360 , 370 , 380 ) may be rotated about one or more of the imaginary axes. When not in the locked position, the cross connector ( 300 ) is operable to properly receive the head of these anchor screws in one or more ways, depending on the specific implanted orientation of the implanted anchor screws. For example, if the orientation of the implanted anchor screw ( 350 ) is rotated relative to the implantation rod axis, as illustrated by uni-directional arrow A, the screw clamp body ( 312 ) can be correspondingly rotated about the first main body ( 311 ) in a similar manner so as to provide for the plane of the adjustable clamp portion ( 312 c ) of the anchor clamp ( 312 ) to be substantially parallel to the plane of the face ( 351 ) of the anchor screw head ( 350 ). Further adjustments, including displacing the first main assembly ( 310 ) in either axial direction along the center link ( 330 ), as depicted by bi-directional arrow B, rotating the first main assembly ( 310 ) about the center link ( 330 ), as depicted by axis C, pivoting the center link ( 330 ) about the first main body, as depicted by axes E and/or F (see FIGS. 5A and 5B ), and/or pivoting the center link ( 330 ) about the second main body axis G, can or may need to be affected to properly receive the anchor screw head ( 351 ) in the adjustable clamp portion ( 312 c ) of the anchor clamp ( 312 ). It is to be understood that corresponding adjustments can be readily made in situations wherein the orientation of the implanted anchor screw ( 350 ) is rotated in the opposite direction. It is also to be understood that corresponding adjustments can be made to the second body assembly ( 320 ) in view of the orientation of the anchor screw ( 350 ). It is also to be understood that, in addition to or in replacement of the said possible orientation of the implanted anchor screw ( 350 ), corresponding adjustments can or may need to be made to the second main assembly ( 320 ) in relation to orientation rotations of the anchor screw ( 370 ). These adjustments to the example embodiment of the cross connector ( 300 ) can be readily made by persons ordinarily skilled in the art.
In another example, if the orientation of the implanted anchor screw ( 350 ) is rotated in either direction relative the center link axis C, the first main assembly ( 310 ) can be correspondingly rotated about the center link ( 330 ) in a similar manner so as to provide for the plane of the adjustable clamp portion ( 312 c ) of the anchor clamp ( 312 ) to be substantially parallel to the plane of the face ( 351 ) of the anchor screw head ( 350 ). Further adjustments, including pivoting the center link ( 330 ) about one of the main assemblies ( 310 , 320 ), as depicted by axes E and/or F (see FIGS. 5A and 5B ), transposing the first main assembly ( 310 ) in either direction along the center link ( 330 ), as depicted by axis B, rotating the first main assembly ( 310 ) about the center link axis, as depicted by bi-directional axis C, pivoting the center link ( 330 ) about the first main body axis E, and/or pivoting the center link ( 330 ) about the second main body axis G, can or may need to be affected to properly receive the anchor screw head ( 351 ) in the adjustable clamp portion ( 312 c ) of the anchor clamp ( 312 ). It is to be understood that corresponding adjustments can be made to the second body assembly ( 320 ) in view of the orientation of the anchor screw ( 350 ). It is also to be understood that, in addition to or in replacement of the said possible orientation of the implanted anchor screw ( 350 ), corresponding adjustments can or may need to be made to the second main assembly ( 320 ) in relation to orientation rotations of the anchor screw ( 370 ). These adjustments to the example embodiment of the cross connector ( 300 ) can be readily made by persons of ordinary skill in the art.
Exemplary adjustments can also be readily made to the orientation and/or position of example embodiments of the cross connector in other non-ideal situations, such as in applications wherein the separation distance between two implanted implantation rods do not allow for the previously-described configurations of having the first and second main assemblies to be applied between the two implanted implantation rods. For example, the cross connector ( 300 ) may be operable so as to position one of the main assemblies ( 310 , 320 ) on opposite sides of an implanted implantation rod ( 390 , 395 ) while still being in communication with the other main assembly through the center link ( 330 ). In example embodiments, both of the main assemblies ( 310 , 320 ) may be positioned on opposite sides of the two implantation rods ( 390 , 395 ) while still being in communication with each other through the center link ( 330 ). In performing either of these adjustments, the cross connector ( 300 ) is adaptably adjustable to accommodate situations where the separation distance between two implanted implantation rods ( 390 , 395 ) would not enable the previously described configurations, as well as conventional cross connectors, to be applied. These adjustments may also be applied along with other adjustments, such as the previously described adjustments, to properly couple implanted anchor screw(s) ( 350 , 370 ) that are implanted in non-ideal positions.
After an example embodiment of the cross connector ( 300 ) is adjusted so as to allow the adjustable clamp portions ( 312 c ) of each of the first anchor clamp ( 312 ) and second anchor clamp ( 322 ) to properly receive the anchor screw heads ( 351 , 371 ) of the anchor screws ( 350 , 370 ) coupled to the implantation rods ( 390 , 395 ), the cross connector ( 300 ) can be fixedly coupled to the implantation rods ( 390 , 395 ) by actuating both the first and second main assemblies ( 310 , 320 ) to the locked position. In an example embodiment of the cross connector ( 300 ), each of the main assemblies ( 310 , 320 ) are actuated to the locked position when their respective set cam assembly ( 315 , 325 ) is turned to the locked position, which causes certain components of the main assembly ( 310 , 320 ) to be displaced from their neutral positions. In the same manner, and with reference to FIG. 4B , each of the main assemblies ( 410 , 420 ) of cross connector ( 400 ) are actuated to the locked position when their respective set screw assembly ( 415 , 425 ) is turned to the locked position, which also causes certain components of the main assembly ( 410 , 420 ) to be displaced from their neutral position.
FIGS. 5A and 5B are top views of an example embodiment of a cross connector ( 300 ) illustrating a pivoting movement of the center link ( 330 ) relative to the main assembly ( 310 ). In FIG. 5A , the center link ( 330 ) can be positioned such that its axis is disposed at an angle +F with respect to the main body axis G. In FIG. 5B , the center link ( 330 ) may also be positioned such that its axis is disposed at an angle −F with respect to the main body axis G. This angle F may be in the range of about +20 degrees to about −20 degrees.
In FIG. 6 , a cross-sectional illustration of an example embodiment of the cross connector ( 300 ) is depicted. When the set screw ( 315 ) in FIG. 6 is turned to the locked position, the cylindrical body portions ( 312 a , 312 b ) of the anchor clamp ( 312 ) are driven towards each other. This applies compression to the anchor clamp ( 312 c ) that is mounted to the head of a screw. As the set screw ( 315 ) is driven into the locked position, a compressive force is also applied to the sides ( 314 b , 314 c ) of the center link clamp ( 314 ) that form the adjustable bore ( 314 a ). This causes the center link clamp ( 314 ) to compress the diameter of the adjustable bore ( 314 a ), thus locking the center link ( 330 ) within the main body ( 300 ). Effectively, the openings of both the adjustable clamp portion ( 312 c ) of the anchor clamp ( 312 ) and the adjustable bore ( 314 a ) of the center link clamp ( 314 ) become adjustably sized as the set screw ( 315 ) is driven so as to securely hold the anchor screw head ( 351 ) and the center link ( 330 ) with respect to the main body, respectively.
While various embodiments in accordance with the disclosed principles have been described above, it should be understood that they have been presented by way of example only, and are not limiting. Thus, the breadth and scope of the invention(s) should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.
Additionally, the section headings herein are provided for consistency with the suggestions under 37 C.F.R. 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically, a description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings herein.
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Example embodiments relate generally to an apparatus operable to couple a pair of implantation rods that are surgically implanted adjacent to a plurality of vertebrae. Each implantation rod is secured by at least one fastener element having a head. The apparatus comprises at least one main assembly, said main assembly operable to move relative to a head of one of the fastener elements when not in a locked position. The apparatus also comprises a center link extending in an axial direction, said center link operable to move relative to the main assembly when not in a locked position. The main assembly is operable to receive the center link and a head of one of the fastener elements and secure the center link and the head relative to the main assembly when in a locked position.
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BACKGROUND OF THE INVENTION
The invention relates generally to reinforcing structures for mounting of load-bearing items. More specifically, the invention concerns mounting reinforcement structures for motor vehicle accessories, such as rear-view mirrors, to be attached to an outer surface of a door of the vehicle.
Currently available mounting reinforcement structures for accessories such as rear-view mirrors for vehicles suffer many drawbacks. Such current products are fashioned from steel and require welding processes to be attached to the door subassembly with attendant tool, labor and maintenance costs. Additionally, such current reinforcing structures do not have self-locating features, therefore requiring locating tools in order to be properly assembled between the inner and outer panels of a vehicle door. Also, currently available reinforcing structures require a retainer to hold the part in place until assembled in the full door assembly.
Stamped steel mirror reinforcement structures currently lack the necessary rigidity to meet systems performance requirements without incurring the cost of increasing the thickness of either the door sheet metal or that of the mirror housing. Additionally, such steel reinforcements are not corrosion resistant.
SUMMARY OF THE INVENTION
A load-bearing reinforcement structure for assisting mounting of a load-producing element to a vehicular body includes a support body having a surface adapted to abut a surface of the vehicular body and a mounting element capable of mechanically connecting the support body to the surface of the vehicular body without a need for welding or use of separate fastening elements, wherein the structure is fashioned from a plastic material.
In another aspect of the invention, a load-bearing reinforcement structure for a vehicular door includes a plate-like element having a first face adapted to at least partially abut an inner surface of one of the vehicle door's inner and outer panels. A plurality of hollow tubular members extend from the plate-like element for a distance substantially equal to a distance between the inner and outer panels of the vehicle door, and a locating and attachment assembly is adapted to attachingly engage one of the vehicle door's inner and outer panels in a preselected orientation with respect thereto.
In yet another aspect of the invention, a vehicle includes a door assembly having inner and outer door panels separated by an interior gap and an injection molded plastic reinforcement structure for the door assembly which includes a plate-like element having a first face at least partially engaging an inner surface of the outer door panel. A plurality of hollow tubular members extend from the plate-like element across the gap to a corresponding plurality of openings in the inner door panel, and a locating and attaching assembly is associated with the first face attachingly engages the outer door panel in a preselected orientation with respect thereto. A hollow conduit extends from the first face across the gap to an inside surface of the inner door panel and in communication with substantially mating openings in the outer and inner door panels. Finally, a loading element is coupled to an outer surface of the outer door panel by a plurality of studs, each extending from the loading element through the outer door panels, through one of the plurality of hollow tubular members, and then through a corresponding opening in the inner door panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the invention will become apparent from a reading of a detailed description, taken in conjunction with the drawing, in which:
FIG. 1 is a perspective view of an outwardly-facing side of a reinforcement structure arranged in accordance with the principles of the invention;
FIG. 2 is a perspective view of an opposite, vehicle interior-facing side surface of the reinforcement structure of FIG. 1 ;
FIGS. 3A–3C present perspective views of a door outer panel receiving the reinforcement structure of the invention; and
FIG. 4 is a perspective view showing the reinforcement structure of the invention installed between the inner and outer door panels of a door assembly.
DETAILED DESCRIPTION
One aspect of this invention is the application of a suitable plastic such as Polyethylene Terephthalate (PET) for structural load-bearing components in vehicle mounting systems, such as for mounting a rear-view mirror at the front area of a vehicle door assembly. PET is an environmentally friendly material with multiple benefits enjoyed over steel. First, the weight of the PET is about one fifth of that of steel and yet has an equal energy absorbing capacity. Other benefits of PET over steel are that it is noncorrosive and has a better damping characteristic, which leads to less vibration.
The mechanical properties of PET are excellent when body components are subject to high temperature, stress and cyclic conditions for long periods of time. PET is a stiffened, super tough thermoplastic polyester and has the highest combined stiffness/toughness of any thermoplastic. In addition, it offers outstanding appearance, high and low temperature performance, good electrical properties and dimensional stability. All these characteristics meet the requirements of the invention for a material having a high melting point—on the order of 350–375° F.—capable of withstanding typical temperatures encountered in paint application and baking chambers in the automotive industry. Additionally, the material is capable of withstanding at least 100 inch-pounds of torque from mirror mounting nuts. The material also exhibits high creep resistance to prevent loosening over the lifetime of the vehicle in multi-temperature environments.
For the purposes of this invention, the preferred PET material is glass reinforced, more particularly, 35–40% mica/glass reinforced. Examples of PET's suitable for this invention are Rynite® 935 and Rynite® 940 commercially available from E. I. DuPont de Nemours and Company.
With reference to FIGS. 1 and 2 , mirror mounting reinforcement structure 100 is fashioned from Rynite® 935 in an injection molding process and features a flat carrier plate surface 102 which substantially matches the surface of the inner facing surface of a door outer panel to provide anti-rattle effect to the door outer panel. Wiring bundle or harness passage 104 is a substantially rectangular conduit extending from inwardly facing surface 202 of the structure for a distance substantially equal to the gap between the inner and outer door assembly panels.
Three mounting stud-receiving tubes 106 a, b, c likewise span the distance between the door inner and outer panels. Tubes 106 a, 106 b and 106 c act as structural columns when a clamp load, such as the rear-view mirror assembly, is applied to the door system.
A locating feature, slot 108 , is cut out of the plate-like structure 100 and engages a member spanning the inner and outer door panels such that the structure 100 will be positioned properly without the use of external positioning tools. Slot 108 is used in conjunction with a locating and installing assembly 110 which includes a flexible tab 112 bearing a locating protrusion 114 on its surface. Raised tangs 116 and 118 are used along with the flexible tab 112 in a manner to be described below for properly mechanically attaching element 100 to an inner surface of the outer door panel and for properly locating it in conjunction with element 108 .
Mounting studs from a device such as the rear-view mirror assembly are received in tubular openings 105 a, b, c, respectively defined by tubes 106 a, b and c.
Stiffening struts 204 , 206 and 208 provide rigidity to structure 100 by coupling the mounting tubes and the wire harness closeout 104 as shown in FIG. 2 .
FIGS. 3A , B and C set forth the method of installation of support structure 100 to an interior surface of door outer panel 302 . As seen from FIG. 3A , door outer panel 302 includes a locator/installing assembly receiving cavity 310 which will receive the locating and installing assembly 110 of structural element 100 . Door outer panel 302 also includes a tab 312 for abutting receipt of flexible tab 112 . Aperture 314 in door outer panel 302 is positioned for mating receipt of locating protrusion pin 114 carried by flexible member 112 . Slots 316 and 318 in door outer panel 302 are positioned for receipt of respective tangs 116 and 118 of the locating and installing assembly 110 of the reinforcement structure 100 . Finally, openings 305 a, b, c in outer panel 302 are aligned respectively with openings 105 a, b, c in reinforcement structure 100 .
In FIG. 3B , after locating and installing assembly 110 has been placed in opening 310 of door panel 302 , the structure 100 is then pushed in a direction marked F in FIG. 3B downwardly such that flexible tab 112 rides up over tab 312 in door panel 302 until its protrusion 114 snaps into place in cavity 314 of panel 302 thereby mechanically attaching structure 100 to panel 302 in the proper orientation, all without the necessity of a welding process or positioning tools.
With reference to FIG. 4 , reinforcement structure 100 is depicted installed between door outer panel 402 and door inner panel 404 . Mirror housing 406 has three mounting studs 408 a, b, c which extend through the mounting columns of structure 100 from the mirror housing 406 through the columns and then through mating apertures in the cabin-facing surface of door inner panel 404 . Additionally, a wiring harness or bundle 410 is seen coming from mirror assembly 406 through the wiring bundle closeout 104 of FIGS. 1 or 2 to a mating aperture in the cabin-facing surface of door inner panel 404 . Each stud 408 a, b, c threaded at its end for receipt of mounting nuts. In this manner, the wiring harness is isolated from the interior space intermediate door inner and outer panels 402 and 404 and is less subject to vibration and attendant noise.
The invention has been described with reference to an exemplary detailed description. The scope and spirit of the invention are to be determined from appropriately interpreted appended claims.
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A load-bearing reinforcement structure for assisting the secure mounting of a load producing element, such as a rear-view mirror assembly, to a vehicular body is advantageously fashioned from a heat and creep resistant plastic, such as glass-reinforced Polyethylene Terephthalate. The reinforcement structure features a mounting element capable of mechanically connecting the reinforcement structure to a surface of a vehicular body, such as an internal surface of a panel of a door assembly, without the need for welding, placement fixtures or use of separate fastening elements.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of tissue ligation, and more particularly to an improved device for dispensing ligating bands.
BACKGROUND INFORMATION
[0002] Physicians have used elastic ligating bands to treat lesions, including internal hemorrhoids and mucositis and for performing mechanical hemostasis. The object of such ligation is to position a ligating band, which is usually elastic, over the targeted lesion or blood vessel section by first stretching the band beyond its undeformed diameter and then drawing the tissue to be ligated within the band. Thereafter the band is released so that it contracts, applying inward pressure on the section of tissue caught within the band. The effect of the inward pressure applied by the band is to stop all circulation through the targeted tissue, thereby causing the tissue to die. The body then sloughs off the dead tissue and the tissue passes naturally through the body.
[0003] U.S. Pat. No. 5,398,844 to Zaslavsky et al. (“the Zaslavsky patent”) and U.S. Pat. No. 5,356,416 to Chu et al. (“the Chu patent”), which are incorporated herein by reference, describe ligating band dispensing devices each including a substantially cylindrical support surface over which elastic ligating bands are stretched. The cylindrical support surface is typically attached to the distal end of an endoscope which is advanced into the body to a target area. A user then applies suction through the endoscope to draw the tissue to be ligated into the cylindrical support surface and releases a ligating band to contract around the tissue.
[0004] Previous ligating band dispensers allowed a user to dispense only a single ligating band at a time. That is, after a single ligating band was dispensed, if a user wanted to ligate another portion of tissue, the user would remove the device from the patient's body, load a new ligating band on the device and reinsert the device to the desired area within the patient's body. The devices of the Zaslavsky and Chu patents allow a user to place several ligating bands at desired locations without removing the device from the patient's body to reload ligating bands. However, the Zaslavsky patent teaches the use of multiple strings to deploy the multiple bands (i.e. a separate pull string for each band), while the Chu patent teaches a ligator including multiple housing and piston segments to deploy the multiple bands.
[0005] U.S. Pat. No. 5,624,453 to Ahmed shows a device in which multiple cords 103 extend from a line element 105 to engage each of a plurality of ligating bands 50. Specifically, each of the cords 103 includes a plurality of knots 109 which are located proximally of each band 50 so that, when the line 105 is drawn proximally, each of the cords 103 is drawn proximally with one knot 109 on each cord 103 being moved distally an equal distance. Each of the knots 109 is substantially equally spaced about the circumference of the adapter 102 so that the force applied via the line 105 is distributed around the circumference of each of the bands 50 and an incrementally increasing amount of slack ensures that when the distal most remaining band 50 is deployed, none of the remaining bands is moved toward the edge of the adapter 102.
[0006] However, the multiple cords 103 extend distally across the field of vision of the endoscope impairing the vision of the operator. In addition, these symmetrically distributed cords 103 cause the line 105 to extend substantially centrally through the lumen of the endoscope, thereby limiting the operator's ability to use this lumen to operate other devices. Finally, as seen in FIG. 18, the cords 103 extend within the adapter 102 in a substantially cone shaped form, coming together at the connector 106. This may impede the drawing of lesion tissue into the adapter 102 under suction or, alternatively, may result in unintended deployment of the bands 50 as the tissue drawn into the adapter 102 pushes the connector 106 proximally. Finally, assembling a device as described in this patent can be very labor intensive—requiring proper placement of all of the multiple cords 103 and the corresponding slack segments with each of the cords being arranged so that the knots 109 are properly positioned with respect to the bands 50.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a ligating band dispenser, comprising a substantially cylindrical support surface capable of holding a plurality of ligating bands, the support surface having a channel extending substantially axially therethrough, wherein a plurality of slots extend away from a distal end of the support surface through at least a portion of the support surface. The ligating band dispenser includes a pull line having a plurality of increased diameter abutting portions, each of the abutting portions having a diameter greater than a diameter of the pull line, the abutting portions defining a plurality of segments therebetween, wherein the pull line extends through the slots with each of the abutting portions being retained within the channel by contact with a corresponding one of the slots and wherein each of the segment segments loops around a corresponding one of the ligating bands.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a schematic drawing illustrating an exemplary pull string according to the present invention.
[0009] [0009]FIG. 2 is a side view of an exemplary ligating band dispenser according to the present invention.
[0010] [0010]FIG. 3 is a partially cut away side view of an exemplary ligating band dispenser according to the present invention having a second dispensing layer.
[0011] [0011]FIG. 4 is a side view of another exemplary ligating band dispenser according to the present invention having an alternate arrangement of the pull string and the ligating bands.
[0012] [0012]FIG. 5 is a side view of an exemplary ligating band dispenser according to the present invention utilizing a second exemplary pull string arrangement.
[0013] [0013]FIG. 6 is a partially cut away side view of another exemplary ligating band dispenser utilizing the pull string arrangement of FIG. 5.
[0014] [0014]FIG. 7 is a side view of an exemplary ligating band dispenser according to the present invention having a plurality of grooves on an external face.
[0015] [0015]FIG. 8 is an end view of the ligating band dispenser of FIG. 7.
[0016] [0016]FIG. 9 in an end view of an exemplary embodiment of a two-layer ligating band dispenser according to the present invention having a plurality of grooves on the external faces.
[0017] [0017]FIG. 10 is a side view of an exemplary ligating band dispenser according to the present invention utilizing a third exemplary pull string arrangement.
[0018] [0018]FIG. 11 is a side view of an exemplary ligating band dispenser according to the present invention utilizing a fourth exemplary pull string arrangement.
[0019] [0019]FIG. 12 is a side view of an exemplary ligating band dispenser according to the present invention utilizing a fifth exemplary pull string arrangement.
[0020] [0020]FIG. 13 is a side view of an exemplary ligating band dispenser according to the present invention utilizing a sixth exemplary pull string arrangement.
[0021] [0021]FIG. 14 is a cross-sectional view of an exemplary ligating band dispenser including a guide ring for a pull string.
DETAILED DESCRIPTION OF THE INVENTION
[0022] [0022]FIG. 1 shows a schematic view of a pull string 801 according to the present invention. Pull string 801 includes, for example, a plurality of knots 501 - 507 arranged along its length, the knots being separated by a plurality of string segments 401 - 406 . It can be understood that many different elements could take the place of and perform the function of knots 501 - 507 . For example, solid objects could be glued, clamped, or otherwise fixed to the pull string 801 . Alternatively (or in addition), a liquid could be applied to points on the string, the liquid beading and then hardening into a solid. Other variations are possible. For purposes of clarity, the description below employs only the term “knot,” but that term is intended to include those embodiments described above as well as other suitable embodiments. It should thus not be construed as a limitation on the present invention.
[0023] [0023]FIG. 2 shows an embodiment of a ligating band dispenser including the pull string of FIG. 1. The ligating band dispenser includes, for example, a substantially cylindrical housing having a distal support surface 100 and an adaptor 101 designed to couple the ligating band dispenser to an endoscope or other suitable device (not shown). While being substantially cylindrical, the housing may have features not shown in the drawings such as a slight taper towards the distal end (the distal end being located to the right in the Figures). The ligating band dispenser includes, for example, a substantially cylindrical channel 111 (not shown on the side views) extending therethrough. Support surface 100 includes, for example, a plurality of slots 301 - 306 , which are smaller, for example, than the knots 501 - 506 . FIG. 2 illustrates a ligating band dispenser holding, for example, six ligating bands 201 - 206 , but the ligating device may include any suitable number of bands.
[0024] The ligating band dispenser may also include, for example, a substantially cylindrical casing 103 attached to the ligating band dispenser, for example, at or near the proximal end of the distal support surface 100 . Casing 103 may cover the distal support surface 100 to ease insertion of the device and to ensure that bands 201 - 206 remain in place while the device travels through the body. As can be seen from FIG. 2, casing 103 may extend further distally than support surface 100 . Casing 103 may also include, for example, an outlet hole 105 near its distal end so that pull string 801 may be drawn beyond support surface 100 , outside casing 103 and away from the lesion and bands 201 - 206 . Further, casing 103 may include an inlet hole 107 near its proximal end so that pull string 801 may be threaded, for example, into adaptor 101 and through the endoscope to the operator.
[0025] The arrangement of bands 201 - 206 and pull string 801 begins, for example, with the proximal-most band 201 (that is, the band appearing furthest to the left of FIG. 2). Knot 501 is placed and retained, for example, behind slot 301 . The term “behind” in this context designates a position within channel 111 . As shown schematically in the Figures, slots 301 - 306 may be shaped, for example, to accommodate knots 501 - 507 in a position behind slots 301 - 306 and to retain knots 501 - 507 in place. With knot 501 retained in place, the pull string 801 may be threaded through slot 301 , so that pull string 801 is outside the ligating band dispenser, and extended proximally along the distal support surface 100 . Band 201 is then stretched over support surface 100 and placed, for example, over pull string 801 near the proximal end of support surface 100 . Once band 201 is in place, the pull string 801 may, for example, be looped back over band 201 . Pull string 801 is then threaded, for example, down through slot 301 and back up through slot 302 . In this manner, knot 502 is retained, for example, between slots 301 and 302 (e.g. behind slot 302 ). Therefore, as shown in the exemplary arrangement of FIG. 2, string segment 401 is wrapped around band 201 , with any slack portion 601 of string segment 401 resting, for example, along the distal support surface 100 proximal to band 201 . Slack portion 601 may, of course, be longer or shorter than pictured in FIG. 2 and other Figures.
[0026] With knot 502 retained, for example, behind slot 302 , pull string 801 can again be extended proximally along the support surface 100 . Band 202 may then be stretched over the support surface 100 and placed, for example, just distal of band 201 . For purposes of clarity, FIG. 2 illustrates some distance between the bands 201 - 206 . Bands 201 - 206 , however, may contact each other if desired. Once band 202 is in place, pull string 801 may be looped over band 202 and threaded through slots 302 and 303 so that knot 503 is retained behind slot 303 . The slack portion 602 of string segment 402 (the portion of pull string 801 looped around band 202 ) may extend proximally over the support surface 100 and be tucked under band 201 .
[0027] In the same manner, pull string 801 may again be extended proximally over support surface 100 . Band 203 may then be placed over pull string 801 and support surface 100 , and pull string 801 may be looped back over band 203 and wound through the appropriate slots. This process may continue until remaining bands 604 - 606 are arranged in the same manner. Specifically, each band 604 - 606 is placed, for example, distally of the previous bands, with the corresponding knot 504 - 506 retained behind a corresponding slot 304 - 306 . Knot 507 may also be retained, for example, behind slot 306 , thereby ensuring that pull string 801 does not migrate distally. It may be noted that, when referring to pull string 801 , “distally” refers to a direction along pull string 801 itself away from the operator, without reference to “distal” or “proximal” portions of the support surface 100 .
[0028] As shown in FIG. 2, the slack portions 603 - 606 of string segments 403 - 406 may be extended proximally over the support housing and, for example, over any proximal bands except band 201 . Slack portions 603 - 606 may then, for example, be tucked under band 201 . It will understood that as each band 601 - 606 is placed on support surface 100 , the corresponding slack increases in each case unless string segments 401 - 406 decrease in length. While string segments 401 - 406 of decreasing length may be employed, in an exemplary embodiment string segments 401 - 406 are equal or substantially equal in length. In this exemplary embodiment, pull string 801 may then be drawn by a spooler (not shown), which may take up the same amount of thread with rotation, for example the amount of thread required to deploy one of bands 201 - 206 .
[0029] To deploy bands 201 - 206 , the ligating band dispenser is fixed, for example, to the end of an endoscope (not shown), inserted into the body, and maneuvered to the desired location. Once the ligating device reaches the desired location, suction, for example, is applied to the lesion as known in the art so that the lesion is drawn, for example, into channel 111 . The operator may then draw pull string 801 proximally (or cause pull string 801 to be so drawn), so that string segment 401 arranged around band 206 is drawn, for example, through the outlet hole 105 and proximally to the operator. Pull string 801 thus takes up the slack portion 606 and begins to urge band 206 toward the distal end of support surface 100 . Because knot 506 is retained behind slot 306 , the portion of the pull string 801 arranged around bands 201 - 205 is not drawn toward the operator, and bands 201 - 205 remain in place.
[0030] Upon reaching the distal end of the support surface 100 , band 206 will deploy to ligate the tissue drawn into the channel 111 . The deployment may be facilitated, for example, by a taper or bevel of the distal end of support surface 100 (not shown). With the band deployed, knot 506 is freed from slot 306 . When the pull string 801 is further drawn to the operator, knot 506 will exit, for example, the outlet hole 105 , allowing band 205 to be deployed in a manner described above. This process may continue with an operator ligating successive portions of tissue with each of the bands 202 - 206 until all of the bands 202 - 206 have been deployed.
[0031] When the ligating band dispenser is fixed to the distal end of an endoscope, the support surface 100 is preferably oriented so that the point where the string 801 extends from the distal rim of the support surface 100 is as close as possible to the lumen of the endoscope through which the string 801 extends back to the operator. This ensures that the string 801 does not interfere with either the field of vision or the drawing of tissue into the channel 111 .
[0032] [0032]FIG. 3 illustrates a second exemplary embodiment of a ligating band dispenser according to the present invention. This second exemplary embodiment includes a second substantially cylindrical support layer 100 a disposed, for example, within support layer 100 . Second support layer 100 a could also be disposed outside support layer 100 , for example between support layer 100 and outer casing 103 . FIG. 3 also shows support layer 100 extending, for example, further distally than second support layer 100 a , but this configuration may also be reversed. Second support layer 100 a contains, for example, additional slots (represented by slot 301 a ), which have the same configuration, for example, as slots 301 - 306 . Second support layer 100 a allows the ligating device to hold a greater number of bands without unsuitably extending the length of the ligating band dispenser.
[0033] Additional bands (not shown) may be arranged on second support layer 100 a , for example, in the same manner as bands 201 - 206 are arranged on support layer 100 . Pull string 801 may include additional knots to deploy the additional bands (represented by knot 501 a ). These additional bands may, for example, be placed on the ligating band dispenser prior to bands 201 - 206 . Bands 201 - 206 may then be arranged as described above. In this manner, band 206 will, for example, be deployed first, followed by bands 201 - 205 in descending order. After bands 201 - 206 are deployed, the additional knots will deploy the additional bands, for example one at a time as described above, until all bands are deployed.
[0034] [0034]FIGS. 4 and 5 illustrate an alternative arrangement of the bands and pull string 801 . The dispenser of FIG. 4 deploys, for example, three bands 201 - 203 . Accordingly, pull string 801 includes, for example, only four knots 501 - 504 , separated by three string segments 401 - 403 . The dispenser, however, still includes, for example, six slots 301 - 306 . To arrange bands 201 - 203 , knot 501 and knot 502 are placed and retained, for example, behind slots 301 and 303 , respectively. String segment 401 , which forms a loop with knots 501 and 502 retained, is extended proximally and placed against the external face of the support surface 100 . Band 201 may then be stretched over support surface 100 and placed over string segment 401 . With band 201 in place, string segment 401 may be folded, for example, back over band 201 and looped between slots 501 and 502 , as shown in FIG. 5. This arrangement forms two loops 401 a and 401 b around band 201 , which will both urge band 201 distally when the pull string 801 is drawn towards the operator.
[0035] Two slack portions 601 and 602 of loops 401 a and 401 b are also formed. These may lay proximally against the external face of the support surface 100 , and may, for example, be of equal length. Alternatively, slack portion 602 may be pulled proximally, thereby extending slack portion 602 and decreasing slack portion 601 until slack portion 601 is minimized (i.e. until loop 401 a has no slack portion 601 ). In this manner, when band 201 is deployed, all the slack portions 601 and 602 will be taken up before either loop 401 a or loop 401 b applies a force to band 201 .
[0036] Once band 201 is placed on the support surface 100 , the pull string 801 may be threaded up slot 303 and back down slot 304 , and knot 503 may be retained, for example, behind slot 305 . String segment 402 is extended, for example, proximally along the external face of the support surface 100 , and band 202 is then placed over string segment 402 . With band 202 in place, string segment 402 may be folded back over band 202 and looped around slots 503 and 504 . This creates loops 402 a and 402 b and slack portions 603 and 604 , which may be arranged as described above. Slack portion 603 , slack portion 604 , or both may be tucked, for example, under band 201 .
[0037] Band 203 may be similarly placed on the support surface 100 . Knot 504 may be retained behind slot 306 to prevent, for example, distal migration of the pull string 801 . In addition, slack portion 605 , slack portion 606 , or both may each be tucked, for example, under band 201 , 202 , or both.
[0038] Note that outer casing 103 , while not shown in FIGS. 4 and 5, may be included in this exemplary embodiment. Other elements not specifically described in conjunction with this particular exemplary embodiment may also be included. It can be understood that this is generally true for each exemplary embodiment described herein: for purposes of clarity, certain elements shown in one pictured embodiment may not appear in other pictured embodiments, but these elements may be included when not shown if desired.
[0039] [0039]FIG. 6 illustrates an exemplary ligating band dispenser with the band/pull line arrangement of FIGS. 4 and 5, having, for example, a second support layer 100 a . The second support layer 100 a shown in FIG. 6 may have, for example, the same structure as the second support layer of FIG. 3. Likewise, the arrangement of the second support layer 100 a of FIG. 6 is analogous to the arrangement of the second support layer of FIG. 3. Specifically, additional bands (not shown) may be placed on second support layer 100 a using, for example, the arrangement described above with respect to the embodiment of FIGS. 4 and 5. Once the additional bands have been loaded, bands 201 - 203 may be loaded, for example, as described with respect to the embodiment of FIGS. 4 and 5. In use, band 203 will, for example, be deployed first, followed by bands 202 and 201 . The additional bands may then be deployed, with the distal-most additional band being deployed first, for example, followed by the remaining additional bands.
[0040] [0040]FIGS. 7 and 8 illustrate another exemplary embodiment of a ligating band dispenser according to the present invention, the ligating band dispenser including a plurality of axially-running grooves 109 formed on the external face of support surface 100 . Grooves 109 , which reduce friction between bands 201 - 206 (not shown) and support surface 100 , are formed, for example, around the entire circumference of support surface 100 . In addition, slots 301 - 306 may each be aligned, for example, along the center of one of grooves 109 .
[0041] [0041]FIG. 9 shows an end view of a ligating band dispenser having grooves 109 of FIGS. 7 and 8. The exemplary embodiment of FIG. 9 includes a second support surface 100 a . As with the embodiment of FIGS. 7 and 8, slots 301 - 306 , as well as slots 301 a - 306 a of support surface 100 a , may be aligned, for example, with grooves 109 . Moreover, slots 301 - 306 may, as a group, be circumferentially offset from slots 301 a - 306 a . This offset allows the pull wire 801 , for example, to traverse the slots 301 - 306 , 301 a - 306 a without excessive circumferential motion. In addition, the relatively small distance between slots 306 and 301 a eliminates the possibility of the pull string 801 not having sufficient length to loop around the bands associated with slots 306 and 301 a.
[0042] FIGS. 10 - 13 illustrate further exemplary embodiments of a ligating band dispenser according to the present invention. The embodiments shown in FIGS. 10 - 13 may deploy, for example, six bands 201 - 206 , but a greater of lesser number of bands may be included. In these embodiments, support surface 100 does not, for example, include any of slots 301 - 306 to retain knots 501 - 506 . Instead, knots 501 - 506 are actively employed, for example, to urge bands 201 - 206 towards the distal end of support surface 100 for deployment.
[0043] In the embodiment of FIG. 10, in order to arrange bands 201 - 206 and pull string 801 , knot 501 of pull string 801 is arranged, for example, on the external face of support surface 100 , with pull string 801 extending from knot 501 distally along support surface 100 . As shown in FIG. 10, knot 501 is disposed, for example, at the extreme distal end of pull string 801 . Band 201 may then be stretched over support surface 100 and pull string 801 , and placed over pull string 801 just distal of knot 501 . Pull string 801 is then wound, for example, around support surface 100 , for example clockwise when viewed from the distal end of the ligating band dispenser, so that knot 501 rests distal of band 201 . The length of string segments 401 - 405 may be such that the pull string 801 winds, for example, approximately once around support surface 100 before the next knot (in this case, knot 502 ) rests against support surface 100 .
[0044] Once knot 502 rests against support surface 100 , band 202 may be stretched over support surface 100 and placed over pull string 801 just distal of knot 502 . Again, pull string 801 may be wound, for example, around support surface 100 until knot 503 rests against support surface 100 , at which point band 203 may be placed over pull string 801 just distal of knot 503 . This process may continue until all bands 201 - 206 are arranged on the support surface 100 .
[0045] To deploy bands 201 - 206 , the ligating band dispenser may be placed over a lesion as described above and the lesion may be drawn into the distal end of the ligating band dispenser as known in the art. Once in place, pull string 801 may be drawn, for example, proximally through the endoscope (not shown) towards an operator. As pull string 801 is drawn proximally, knot 506 will be drawn distally along support surface 100 , contacting band 206 and pulling band 206 towards the distal end of support surface 100 and eventually deploying band 206 . As knot 506 is pulled, pull string 801 unwinds, for example, around support surface 100 , taking up any slack in pull string 801 . After band 206 is deployed and any slack taken up (which may be accomplished, for example, with one turn of a spool taking up pull string 801 ), the ligating band dispenser is ready to deploy band 205 .
[0046] As described above, when the ligating band dispenser is fixed to the distal end of an endoscope, the support surface 100 is preferably oriented so that the point where the string 801 extends from the distal rim of the support surface 100 is as close as possible to the lumen of the endoscope through which the string 801 extends back to the operator. This ensures that the string 801 does not interfere with either the field of vision or the drawing of tissue into the channel 111 . This also allows the operator to employ the lumen to introduce other devices to the distal end of the endoscope.
[0047] [0047]FIG. 11 illustrates another exemplary embodiment of a ligating band dispenser having an arrangement similar to the dispenser of FIG. 10. In the embodiment shown in FIG. 11, however, a plurality of knots may be employed between each pair of bands 201 - 206 . For example, knot 506 of FIG. 10 corresponds to knots 506 a - 506 d of FIG. 11. These additional knots ensure that even if one of knots 506 a - 506 d (e.g. knot 506 a in FIG. 11) slips under band 206 , band 206 will not be stranded on support surface 100 . Of course, more or less than four knots may be used. In addition, although FIG. 11 shows only one knot behind band 201 , additional knots may be included behind band 201 as well.
[0048] [0048]FIGS. 12 and 13 illustrate alternative arrangements of string segments 401 - 405 , which essentially form slack between knots 501 - 506 . In the arrangement of FIG. 12, string segments 401 - 405 are, for example, looped and arranged proximally along support surface 100 . These may be tucked, for example, under any bands proximal to the corresponding knot, tucked under all such bands, or lain over top of such bands. In the arrangement of FIG. 13, string segments 401 - 405 are wound, for example, around support surface 100 as in FIG. 10. In the arrangement of FIG. 13, however, the direction of winding changes for each consecutive string segment 401 - 405 , creating a “zig-zag” path of the pull string 801 .
[0049] [0049]FIG. 14 illustrates a further exemplary feature of a ligating band dispenser according to the present invention, a guide ring 115 . To prevent any precession of the pull string 801 around the support surface 100 , pull string 801 may be threaded, for example, through guide ring 115 . Guide ring 115 may be disposed, for example, on the internal face of support surface 100 (i.e. within channel 111 ). Guide ring 115 may, of course, be present in any of the embodiments described above.
[0050] The present invention has been described with respect to several exemplary embodiments. There are many modifications of the disclosed embodiments which will be apparent to those of skill in the art. It is understood that these modifications are within the teaching of the present invention which is to be limited only by the claims.
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A ligating band dispenser comprises a substantially cylindrical first support surface capable of holding a plurality of first ligating bands. The first support surface has a first channel extending substantially axially therethrough and a plurality of first slots extending away from a distal end thereof through at least a portion of the first support surface. A plurality of increased diameter abutting portions define a plurality of segments of a pull line extending through the slots with each of the abutting portions being retained within the channel by contact with a corresponding one of the slots. Each of the segments loops around a corresponding one of the ligating bands to releasably couple the pull line to the ligating bands.
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RELATED APPLICATIONS
[0001] This application claims benefit of earlier filed U.S. Provisional Application having Ser. No. 60/988,884.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCED OR INCORPORATED MATERIAL
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] The present invention relates to the field of debris collection and more specifically to a device for the efficient collection of debris. Debris, as used herein, is a term describing articles displaced in an environment. Typically it is desirable to collect such debris in order to dispose of it though the debris may be equally wanted or unwanted debris. For example, the debris may be unwanted litter along a highway or it may be fallen pine cones in a homeowner's yard. In any such case, the present invention may be utilized in collecting the debris for whatever purposes the collector may decide, though typically, this intention would be disposal of said debris.
SUMMARY OF THE INVENTION
[0005] The present invention is a device for the collection of debris. The invention is designed to be utilized primarily by a single person though it is also envisioned that teams of human debris collectors may be employed towards a given debris collection task. In this way, a collection team may use multiple copies of the device to collect debris distributed across a large field.
[0006] Designed to be held by one hand, the invention features a handle linearly displaced from sharp spikes which penetrate debris by downward pressure. This pressure is applied both by the weight of the device as well as a force projected by the human operator. As the operator approaches an article of debris, the operator punches down on the article, the spikes pierce and penetrate the article, and the article thus becomes lodged on the spike head of the device. The spike head is designed to hold many articles before becoming full.
[0007] When a collection field contains many articles of debris, the spike head may fill with debris many times during a collection. When full, the device is designed to be self emptying. The device features a trigger system whereby the operator actuates a trigger and the accumulated debris is thereby ejected from the spike head into appropriate receptacles or other appropriate locations.
[0008] Another important aspect of the device comes with respect to the spikes. The native resting position of the device is the ejected position which results with the spikes being shielded as opposed to being exposed in the loaded position. This may present a safety benefit by having the spikes be secured from imposing bodily injury when the device is in storage.
[0009] Yet another important aspect relates to the replacement life of the device. Each of the spikes used in the device may easily be replaced when an individual spike becomes worn after continual long term use. This may prevent the operator from having to replace the entire unit.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] FIG. 1 is an environmental perspective view showing the device being used to collect debris.
[0011] FIG. 2 is a perspective view of the device in the loaded position.
[0012] FIG. 2A is a perspective view of the device in the loaded position and highlighting the trigger in the loaded position.
[0013] FIG. 2B is a perspective view of the device highlighting how the ejection plate operates with respect to the pusher rod.
[0014] FIG. 3 is a side view of the device in the loaded position.
[0015] FIG. 4 is a side view of the device in the ejected position.
[0016] FIG. 5 is an exploded view of the device.
DETAILED DESCRIPTION
[0017] It is to be understood by a person having ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention. The following example is provided to further illustrate the invention and is not to be construed to unduly limit the scope of the invention.
[0018] The present invention is a device for the collection of debris. The invention comprises a handle ( 10 ), a shaft ( 20 ), an ejection trigger system, and a collection head. The handle ( 10 ) is ergonomically designed to afford the operator a power grip (see FIG. 1 ) on the device. In the preferred embodiment, the handle ( 10 ) is made of metal and is padded with plastic or foam.
[0019] Like the handle ( 10 ), the shaft ( 20 ) is made of metal in the preferred embodiment and is attached to the handle ( 10 ) and to the collection head thereby spanning the vertical distance between the two. The shaft ( 20 ) is fixedly attached to the handle ( 10 ) at its upper end and removably attached to the collection head at its lower end. The shaft ( 20 ) is cylindrical in the preferred embodiment and is hollow such that the trigger system operates within the shaft ( 20 ). The shaft ( 20 ) further comprises an attachment plate ( 24 ) and a hook shaped trigger slot ( 21 ) through which the trigger operates from a loaded position (see FIG. 3 ) to an ejected position (see FIG. 4 ).
[0020] The attachment plate ( 24 ) is attached to the cylindrical portion of the shaft ( 20 ) at the lower end. The attachment plate ( 24 ) is the point of attachment of the shaft ( 20 ) to the collection head. In the preferred embodiment, the attachment plate ( 24 ) removably attaches to the collection head via metal screws ( 23 ).
[0021] The hook shaped trigger slot ( 21 ) of the shaft is a slot in the shape of an inverted fish hook which is cut into the cylindrical wall of the shaft ( 20 ). When at the top of the hook ( 26 ), the trigger is in the loaded position (see FIG. 3 ). When at the bottom of the hook ( 25 ), the trigger is in the ejected position (see FIG. 4 ).
[0022] The trigger system operates largely inside of the shaft ( 20 ) and is essential to the heart of the invention. The trigger operates from a loaded position (see FIG. 3 ) to an ejected position (see FIG. 4 ). In the loaded position, the collection spikes ( 70 ) are exposed and ready to collect debris. In the ejected position, the collection spikes ( 70 ) are safely covered and any debris previously collected has been ejected. Moving between the two positions, the trigger system utilizes a spring force acting in compression. When the trigger ( 31 ) is actuated by a human collector operating the device, the release of the spring force in compression moves the trigger ( 31 ) from the top of the hook ( 26 ) to the bottom ( 25 ) thereby ejecting the debris. To reset the device, the human collector operating the device pulls the trigger ( 31 ) back to the top of the hook ( 26 ) to the loaded position.
[0023] To achieve this trigger ejectment action, in the preferred embodiment, the trigger system further comprises a trigger handle ( 31 ), a trigger actuator ( 32 ), a pusher rod ( 30 ), a compression spring ( 34 ), a spring pusher ( 33 ), an indention point ( 22 ), and a spring stop ( 35 ). The trigger handle ( 31 ) is the means by which the human collector manipulates the trigger and moves it between the loaded position (see FIG. 3 ) and the ejected position (see FIG. 4 ). The trigger handle ( 31 ) is constrained in movement by the hook shaped trigger slot ( 21 ). The trigger handle ( 31 ) is removably attached to the trigger actuator ( 32 ) which is effectively the point of attachment between the trigger handle ( 31 ) and the pusher rod ( 30 ).
[0024] The pusher rod ( 30 ), located within the cylindrical cavity of the shaft ( 20 ), extends the length of the device from above the top of the hook shaped trigger slot ( 21 ) of the shaft ( 20 ) to the collection head. The spring pusher ( 33 ) is slidingly attached to the pusher rod ( 30 ) such that it may only move freely in the linear direction of the pusher rod ( 30 ). The spring pusher ( 33 ) is also constrained in linear movement by the indentation point ( 22 ) just below the extreme lower point of the hook shaped trigger slot ( 21 ) of the shaft ( 20 ). The indentation point ( 22 ) prevents the spring pusher ( 33 ) from moving above the lowest point of the hook shaped trigger slot ( 21 ) of the shaft.
[0025] Like the spring pusher ( 33 ), the compression spring ( 34 ) is slidingly attached to the pusher rod ( 30 ) and is free to move in the linear direction of the pusher rod ( 30 ). The compression spring ( 34 ) is, however, constrained by the spring pusher ( 33 ) at its upper point and by the spring stop ( 35 ) at its lower point. The spring stop ( 35 ) is much like the spring pusher ( 33 ) excepted it is fixedly attached to the pusher rod ( 35 ).
[0026] Thus, when manipulated to the loaded position, the trigger handle ( 31 ) is pulled up to the top of the hook shaped trigger slot ( 21 ) which, in turn, pulls the pusher rod ( 20 ) upward thereby also pulling the spring stop ( 35 ) upwards. As the spring stop ( 35 ) is pulled upwards the compression spring ( 34 ) moves upwards as does the spring pusher ( 33 ) which becomes pressed against the indentation point ( 22 ). Once the spring pusher ( 33 ) is pressed against the indentation point ( 22 ), the compression spring ( 34 ) begins to enter tighter compression as the pusher rod ( 30 ) and, thereby, the spring stop ( 35 ) continues being pulled upwards. This loading process continues until the trigger handle ( 31 ) has been pulled to the top of the hook shaped trigger slot ( 21 ) of the shaft ( 20 ) and is resting in the hook portion (at the top) of the hook shaped trigger slot ( 21 ). At that point when the trigger is resting in the loaded position, the spring pusher ( 33 ) is firmly pressed against the indentation point ( 22 ), the compression spring ( 34 ) is tightly compressed between the spring stop ( 35 ) and the spring pusher ( 33 ), and the pusher rod ( 30 ) has brought the collection head into a loaded position (see FIG. 3 ) where the collection spikes ( 70 ) are exposed and ready to be loaded with debris.
[0027] Accordingly, when the trigger handle ( 31 ) is moved over the hook portion of the hook shaped trigger slot ( 21 ) of the shaft ( 20 ), the compression spring ( 34 ) is released placing a downward force on the spring stop ( 35 ) and thereby the pusher rod ( 30 ) which causes the respective elements of the collection head (which are explained in greater detail below) to eject whatever debris has been collected by the collection spikes ( 70 ) and thereby come to rest in the ejected position (see FIG. 4 ).
[0028] As stated above, the collection head moves from a loaded position (see FIG. 3 ) to an ejected position (see FIG. 3 ) as articulated by the trigger system operating inside the shaft ( 20 ). The collection head comprises a system of plates and spikes which collect and eject collected debris. This system of plates and spikes further comprises a backing plate ( 40 ), a spike plate ( 50 ), an ejection plate ( 60 ), a plurality of spikes ( 70 ), a pair of shoulder bolts ( 80 ), and a pair of attachment screws ( 23 ). In the preferred embodiment, the spikes ( 70 ) are comparable to sharpened eight penny nails with round heads.
[0029] The backing plate ( 40 ), the spike plate ( 50 ), and the ejection plate ( 60 ) are generally rectangular and have the same length and width though the thickness can vary. In the preferred embodiment, these parts are metal though the invention is not limited to metal as the plates may also be made of polymers or other composite materials.
[0030] The spike plate ( 50 ) holds the spikes ( 70 ) and the backing plate ( 40 ) secures the spikes ( 70 ) in place. The spike plate ( 70 ) has counter sunk holes ( 54 ) through which the spikes ( 70 ) rest with the tops of the spike heads being flush with the top surface of the spike plate ( 50 ). The spike plate ( 50 ) has a pair of threaded holes ( 53 ) that are aligned with a pair of slightly larger holes of the backing plate ( 43 ). A pair of threaded attachment screws ( 23 ) passes through a pair of holes ( 43 ) in the attachment plate ( 24 ) of the shaft and through the pair of holes ( 43 ) of the backing plate ( 40 ) to mesh with the threaded holes ( 53 ) of the spike plate ( 50 ). As these attachment screws ( 23 ) are tightened, the backing plate ( 40 ) and the spike plant ( 50 ) of the collection head are removably attached to the shaft ( 20 ). Also, as these attachment screws ( 23 ) are tightened, the backing plate ( 40 ) locks against the spike plate ( 50 ) firmly fixing the spikes ( 70 ) in place.
[0031] When in the course of debris collection it becomes necessary to replace a damaged spike, the human operator need only temporarily remove the attachment screws ( 23 ), separate the backing plate ( 40 ) from the spike plate ( 50 ), and exchange the damaged spike with a new spike. The human operator would then reattach the backing plate ( 40 ) and spike plate ( 50 ) and reset the attachment screws ( 23 ).
[0032] Both the backing plate ( 40 ) and the spike plate ( 50 ) each have three more aligning holes. One of these holes ( 42 and 52 , respectively) is disposed in the center of the respective plates. This central hole allows the pusher rod ( 30 ) of the trigger system to pass from the shaft ( 20 ) through backer plate ( 40 ) and the spike plate ( 50 ) unobstructed to the ejection plate ( 60 ).
[0033] The other pair of holes ( 41 and 51 , respectively) referenced above, which pass through the backing plate and the spike plate, facilitate the shoulder bolts ( 80 ) which are attached to the ejection plate ( 60 ). With respect to the backing plate ( 40 ), these holes ( 41 ) may be cylindrical holes or they may be slots cut into the backing plate ( 40 ) as shown in the drawings. Such holes ( 41 ) will be larger than the head of the shoulder bolts ( 80 ). With respect to the spike plate ( 50 ), they are a pair of holes ( 51 ) sized just larger than the shaft of the shoulder bolts ( 80 ) but smaller than the head of the shoulder bolts ( 80 ).
[0034] The shoulder bolts ( 80 ) are a pair of bolts with outward threading at the lower end, a large head at the upper end, and a smooth, level cylindrical surface or shaft between the lower and upper ends. The lower threaded end of the shoulder bolts ( 80 ) are removably attached via threaded connection to the ejection plate ( 60 ).
[0035] The ejection plate ( 60 ) is used to eject the debris from the collection head and to serve as a safety mechanism when the device is not being used. It operates from a loaded position (see FIG. 3 ) with the spikes ( 70 ) exposed to an ejected position (see FIG. 4 ) with the spikes ( 70 ) shielded. The pusher rod ( 30 ) which extends through the shaft ( 20 ), through the backer plate ( 40 ), and through the spike plate ( 50 ), terminates at and is fixedly attached to the ejection plate ( 60 ) at connection point ( 62 ). The ejection plate ( 60 ) has a plurality of holes ( 63 ) which are aligned with the spikes ( 70 ) such that when the spikes pass through the ejection plate ( 60 ), the spikes ( 70 ) will be parallel. When the device is in the loaded position (see FIG. 3 ), the ejection plate ( 60 ) will be in close proximity to the spike plate ( 50 ) with the spikes ( 70 ) being exposed through the holes ( 63 ) in the ejection plate ( 60 ). Moreover, when the device is in the loaded position (see FIG. 3 ), the head of the shoulder bolts ( 80 ) will be elevated above the level of the backing plate ( 40 ). When the device is in the ejected position (see FIG. 4 ), the ejection plate ( 60 ) will be further from the spike plate ( 50 ) such that the sharpened tips of the spikes ( 70 ) are just inside the holes ( 63 ) of the ejection plate ( 60 ). Moreover, when the device is in the ejected position (see FIG. 4 ), the head of the shoulder bolts ( 80 ) will be resting on the top surface of the spike plate ( 50 ).
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The invention is a device for the safe and efficient collection of debris displaced across a collection field. Utilizing a plurality of spikes which pierce and penetrate articles of debris, the invention contemplates the accumulation of articles of debris on the spikes. When the device has become loaded with debris, the device self ejects the debris using a compression spring force trigger mechanism.
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FIELD OF THE INVENTION
This invention relates to apparatus for and method of time-resolved Fourier Transform optical spectroscopy, FT-IR (Fourier Transform-Infrared) in particular as examplified by its application to DIRLD (Dynamic Infra Red Linear Dichoism) spectroscopy.
BACKGROUND OF THE INVENTION
For a better understanding of the background from which the invention springs, but with no prejudice to the generalities expressed in the claims accompanying the present specification, the introduction which follows will relate to time-resolved FT-IR spectroscopy, which is becoming widely practised and shows a promising future.
In a non-time-resolved regular FT-IR spectrometer, introduced here by way of background information, an interferometer of the Michelson type splits a polychromatic input beam into a reflected beam and a transmitted beam by means of a beam splitter. Each split beam travels along its own path to a return mirror which deflects it back to the beam splitter along the same path. One of the return mirrors is stationary, whilst the other is movable along a rectilinear track between two mirror travel limits equidistant from a datum position therebetween. At the beam splitter, the two returned split beams recombine along a co,non output path leading to a photodetector via a sample station.
If the movable mirror is adjusted so that the optical path length from beam splitter to return mirror and from the latter back to the beam splitter is exactly the same for the two beams, i.e. if the movable mirror is located at its datum position, then the two halves of each constituent split optical wave, one half in one split beam and the other half in the other split beam, will undergo constructive interference, which means that respective wavefronts will overlap. In other words, at the datum position or, more specifically, zero OPD (Optical Path Difference) position, all the constituent waves of the input beam which were split by the beam splitter will recombine simultaneously, as shown by the dominant signal produced by the photodetector. This intense signal is referred to in the art as the centreburst.
If the movable mirror is now shifted towards the incoming split beam, the optical path length "seen" by the movable mirror is decreased; conversely, it will be increased if the mirror is moved in the opposite direction. A mirror travel from one to other limit will therefore generate two complete series of OPD values of opposite signs, as required for Fourier transformation, presently to be introduced. Such travel is referred to as an OPD scan. Each OPD change from the zero OPD position of the movable mirror corresponding to one half wavelength of a constituent optical wave will produce a sinusoidal optical modulation of the wave varying at recombination from a maximum when the two split waves are in phase (constructive interference) to a minimum when they are in phase opposition (destructive interference). In terms of the photodetector signal, it means that as the OPD scan proceeds a series of superimposed electrical sine waves will be generated of different frequencies (known as Fourier frequencies) and amplitudes. That signal represents an interferogram.
So far no reference has been made to the presence of a sample at the sample station. If a sample is inserted, the interferogram taken is that of the sample superimposed on that of the source. If no sample is inserted, the resulting interferogram is that of the source, of course. By taking the Fourier Transform of the former interferogram and, separately, that of the latter and ratioing the two transforms, the spectrum of the sample is obtained.
It is desirable to emphasize that an interferogram is sampled as a series of elemental data (hereinafter data points) and the OPD scan from mid-scan to either scan limit is divided into a corresponding series of equal OPD increments (hereinafter OPD points), each in coincidence with a zero crossing of a reference laser interferogram. A data point occurring at a given position in the series of data points is always sampled at the OPD point occupying the same position in the series of OPD points. Thus data point 1 is always sampled at OPD point 1, data point 2 at OPD point 2, and so on.
Fuller background details are contained in the introduction to U.S. Pat. No. 4,684,255, which is imported in full into this specification and is hereinafter referred to as Imported Patent.
Time-resolved FT-IR spectrophotometers are known in which to the multiple modulation covering a band of Fourier frequencies provided by the interferometer (hereinafter referred to as interferometer modulation) in translating each optical wave present in the interferometer input beam into an electrical sine wave, the amplitude and frequency of which are related to amplitude and frequency of the optical wave, there is added a cyclic stretching and relaxing of the sample in the shape of a thin strip by means of a rheometer. These mechanical cyclic perturbations are hereinafter referred to as sample modulation. Depending on the nature of the sample, the perturbations may cause changes in certain constituent dipole moments of a molecule and, consequently, in the dipole moment of the molecule as a whole.
Whenever the dipole moment of a molecule changes, absorption takes place. The change in dipole moment brought about by sample modulation may be regarded as "dynamic" absorption to distinguish it from the "static" absorption of conventional FT-IR spectroscopy, wherein an unperturbed sample is used. By accumulating data at each successive OPD points of an OPD scan by the interferometer which synchronize with sample strain resulting from the stress applied by the cyclic perturbations, it is possible to derive a spectrum on the time-dependence of absorbance, which when compared with the static spectrum provides information useful in the interpretation of the latter e.g. in resolving a featureless absorbance band into a number of constituent peaks.
Another well known FT-IR technique is concerned with Infra Red Linear Dichroism (IRLD). Samples that absorb light differentially between two orthogonal components of linearly polarized light are said to exhibit dichroism. This effect occurs naturally in certain crystalline materials, such as tourmaline, and may be induced by stretching in others, such as atactic polystyrene. In this specification, the phrase dichroic sample shall be understood to refer to a sample in which dichroism is either natural or induced.
In regular IRLD, an ultrasonic photo-elastic modulator, referred to as the PEM, causes an interferometer output beam that has been linearly polarized to alternate between two orthogonal linearly polarized states at an ultrasonic frequency. The sample is so orientated that its dichroic axis is either parallel or perpendicular to the modulation axis of the PEM. As it passes through the sample, the polarization modulated beam is differentially absorbed between the two orthogonal polarization states. A detector receiving the emerging beam yields an electrical output in which a wave at the ultrasonic polarization frequency appears atop a waveform representing the emission interferogram of the interferometer source compounded with the regular IR absorbance interferogram of the sample. The linear dichroism difference information is contained in the modulation of the ultrasonic wave. The "envelope" of this modulation may be extracted and processed by known means to provide the linear dichroism difference spectrum of the sample.
Another FT-IR technique results from the combination of polarization modulation with sample modulation. It is known as DIRLD, which stands for Dynamic Infra-Red Linear Dichroism, in contradistinction to IRLD which may be thought of as "static" IRLD. Now the modulation of the ultrasonic wave in the detector output contains information on dichroism components respectively in phase and in quadrature with sample strain. This information may be extracted by known methods and displayed as dynamic dichroic difference spectra side by side with the static dichroic difference spectrum of the sample.
In the application of the prior art FT-DIRLD technique the aim has been to establish the time dependence of absorbance in a dichroic sample. It was soon realized that if the interferometer band of modulation frequencies was too closely spaced from the sample modulation frequency, sidebands of the former would interfere with certain frequencies within the said band. Unfortunately, the obvious remedy of distancing the sample modulation frequency sufficiently to avoid interference effects was not available because the choice of such frequency is governed by the requirements of the analysis to be undertaken and the nature of the sample. The answer was to replace continuous OPD scanning by step scanning. It has meant: stopping the scan at the first OPD point of a complete scan for the duration of one cycle or more of the sample modulation; sampling the interferogram for various phase angles of the or each sample modulation cycle; repeating the process at each subsequent OPD point until completion of the scan; and analyzing the data.
Unfortunately, the step scanning system required hitherto is complex and therefore expensive; more importantly, OPD scanning can take several hours and no spectra is produced till the very end. The prior art solution avoids the interference problem referred to earlier but incurs a severe penalty. Not being able to use the fast scan facilities is also a serious drawback in time resolved FT spectroscopy.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention there is provided a time-resoved FT optical spectrophotometer, comprising:
a) a Michelson-type interferometer;
b) a photodetector for co-operating with the interferometer in producing an electrical output of interferomtric data;
c) means for introducing cyclic perturbations which permit the time dependence of a parameter that in operation will be subjected to analysis to be evaluated from their effect on the interferometric data.
d) signal generating means for generating a reference signal in phase with the cyclic perturbations and a reference signal in quadrature with the perturbations;
e) means for reading the interferometric data and the reference signals at each OPD point of the interferometer over a sequence of interferometer scans; and
f) means for computing at each OPD point from the interferogram and reference signals readings certain parameters defining the time dependence of the parameter under analysis and for generating the spectra of said parameters.
Means may be provided for arranging the read data as a best fit to a model such that, when such fit is obtained, a series of read interferogram data points is obtained each of which is correctly correlated to the phase angle of the in phase reference signal at which it occurred as a result of the perturbations, whereby from the read interferogram a derived interferogram may be generated representing the demodulated in phase component of the read interferogram.
Means may also be provided for arranging the read data as a best fit to a model such that, when such fit is obtained, a series of read interferogram data points is obtained each of which is correctly correlated to the phase angle of the in quadrature reference signal at which it occurred as a result of the perturbations, whereby from the read interferogram a derived interferogram may be generated representing the demodulated in quadrature component of the read interferogram.
The best fit model may be an ellipse.
The means for introducing cyclic perturbations may be adapted to cause mechanical or electrical perturbations or, indeed, of any other nature that will permit the stated function to be performed.
The parameter under analysis may be a system parameter, such as, for example, the emission spectrum of an electro-fluorescent lamp system, or a parameter, such as linear dichroism, of a regular analytical sample.
Means may be provided for subjecting the analytical sample to cyclic mechanical perturbations such as in the form of cycles of alternate stretching and relaxing to establish the time dependence of a parameter of the sample, e.g. light absorbance.
A rheometer may be used to create cyclic stretching and relaxing, in which case the strain gauge associated with such instrument may constitute the means for providing the reference signal in phase with the cyclic perturbations and the in quadrature reference signal may be derived from the thus obtained in phase reference signal by means of a device capable of introducing a 90-degree phase shift.
The FT optical spectrophotometer may further include a linear polarizer followed by an ultrasonic photo-elastic modulator to adapt the spectrophotometer for time resolved spectroscopy in accordance with the DIRLD (Dynamic Infrared Linear Dichroism) technique.
In accordance with another aspect of the present invention there is provided a method of FT spectrosopy for evaluating the time dependence of a parameter under analysis, comprising the steps of:
a) subjecting the parameter to interferometric analysis as in regular FT spectroscopy for the generation of interferometric data;
b) introducing cyclic spectroscopic perturbations that permit the time dependendence of the parameter to be evaluated from their effect on the interferometric data;
c) generating two reference signals, one in phase and one in quadrature with the cyclic perturbations;
d) reading the interferomtric data and the reference signals at each interferometric OPD point over a sequence of OPD scans;
e) computing in correspondence of each OPD point from readings of the interferogram produced by the interferometric analysis as modified by the cylic perturbations and from readings of the reference signals certain parameters defining the time dependence of the parameter under analysis; and
f) generating the spectra of said parameters.
The read data may be arranged as a best fit to a model such that, when such fit is obtained, a series of read interferogram data points is obtained each of which is correctly correlated to the phase angle of the in phase reference signal at which it occurred as a result of the perturbations, whereby from the read interferogram a derived interferogram may be generated representing the demodulated in phase component of the read interferogram.
Furthermore, the read data may be arranged as a best fit to a model such that, when such fit is obtained, a series of read interferogram data points is obtained each of which is correctly correlated to the phase angle of the in quadrature reference signal at which it occurred as a result of the perturbations, whereby from the read interferograma derived interferogram may be generated representing the demodulated in quadrature component of the read interferogram.
The best fit model may be an ellipse.
Both in terms of apparatus and method the present invention leads to many varied applications. It may, for example, enable a time dependent parameter to be segregated so that certain undesired effects may be eliminated, e.g. thermal background in the measurement of Raman scatter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of apparatus that cooperates with the FT spectrophotometer from the Imported Patent in the realization of an embodiment of a time-resolved FT spectrophotometer adapted for the application of the DIRLD technique;
FIG. 1A is a simplified drawing of a prior art photo-elastic modulator included in the embodiment;
FIG. 1B is a simplified drawing of a prior art rheometer included in the embodiment;
FIG. 1C is and X-Y plot of data illustrating a best fit method forming part of the embodiment;
FIG. 2 is a flow chart of the data processing involved in the performance of the best fit method;
FIG. 3 represents FIG. 7 (Imported Patent) as modified for the purposes of the embodiment.
DETAILED DESCRIPTION OF THE INVENTION
In the DIRLD apparatus shown diagrammatically in FIG. 1, the recombined beam originating from scanner 13 that has emerged from parabolic mirror 22, both shown in FIG. 4 (see also FIG. 5) of the Imported Patent, identifies with beam IB, having by-passed the sample in carrier 23, the elliptical mirror 24, and detector 9, all of which are substituted in FIG. 1 of the present specification by parts which, although performing a generally similar function, differ in their physical characteristics from the substituted parts, as will be presently appreciated.
Beam IB successively traverses a polarizer 100, a photo-elastic polarization modulator 101 (hereinafter referred to as the PEM), a rheometer 102 for subjecting a sample in the form of a thin film to cycles of stretching and relaxing, and a focussing lens 103 for projecting an image of the Jaquinot stop 2A (FIG. 4 of Imported Patent) onto a photoconductive MCT (mercury-cadmium-telluride) detector 104. The rheometer 102 with a sample fitted to it is reminiscent of the discarded sample carrier 23 in FIG. 4 of the Imported Patent, in so far as the sample carrying function is concerned; but there the similarity ends, except that it too must be so mounted that an image of the Jaquinot stop 2A (FIG. 4 of Imported Patent) is formed at, or in close proximity to, the sample plane.
The electrical output of the MCT detector 104 is extended, via amplifier-cum-linearizer 105, to lock-in amplifier 106 comprising a high-pass filter 106A feeding into a synchronous detector 106B which receives a 74 kH signal from a frequency doubler 106C via a phase adjuster 106D. The input to the frequency doubler 106C is a 37 kHz phasing signal from the PEM 101. The output of the synchronous detector 106B feeds, via a low pass filter 106E, into a multiplexer 107 controlled by control logic 108, which in turn responds to an input, referenced Hd, from the signal pulse generator 50 shown in FIG. 7 of the Imported Patent. The output of the multiplexer 107, referenced S1, is linked, via sample and hold unit 44, to the input of PG,13 ADC (analogue-to-digital converter) unit 45 (FIG. 7 of the Imported Patent), which is triggered in parallel with the control logic 108 by trigger pulse generator 50 (FIG. 7 of the Imported Patent).
The multiplexer 107 receives two further inputs, each representing a reference signal: a first sinusoidal (cosine) signal from a strain gauge within the rheometer 102, via sample and hold device 109, in phase with the strain suffered by the sample when subjected to cyclic stretching and relaxing; and a second sinusoidal (sine) signal, also originating from the strain gauge, via a 90-degree phase shifter 110 and sample and hold device 111. The two signals provide therefore two references respectively in phase and in quadrature with the cyclic sample strain. Devices 109 and 111 act simultaneously in response to control logic 108.
All the optical and electronic units introduced hereabove with reference to FIG. 1 are well known in the optical and electronic arts, respectively, and are available commercially. The information which follows on a few of them is offered in the interest of a ready understanding of the invention.
The purpose of polarizer 100, a silver bromide wire-grid unit, is to provide linear polarization of beam IB in the direction of the strain caused in the sample by the rheometer 102. In FIG. 1 it is assumed that the sample is being stretched and relaxed in a vertical direction. Therefore, the chosen plane of polarization of the polarizer 100 is vertical.
The function of the PEM 101 is to switch the plane of polarization from vertical to horizontal in a cyclic manner. The input beam IB is, therefore, alternately polarized in directions parallel and normal to the strain direction of the sample. The PEM 101 used in this embodiment is an instrument marketed as the "PEM-90" photo-elastic modulator by Hinds Instruments Inc., of 5250, NE Elam, Young Darkway, Hillsboro, Oreg. 97124-6463, U.S.A. It is based on a ZnSe plate 101A (FIG. 1A) in which strain induced birefringence is generated by an ultrasonic piezo-electric transducer 101B acting on the top edge of the plate 101A. The transducer 101B is energized via conductors 101C and 101D from a control unit 101E. The operating frequency of the transducer 101B is 37 kHz, and since the polarization vector is being switched twice per cycle, the polarization modulation frequency of beam IB is 74 kHz. The control unit 101E makes available a 37 kHz phasing signal to the frequency doubler 106C (FIG. 1) via cable 101F.
The PEM 101 enables a linear dichroic difference signal to be monitored on a continuous basis via MCT detector 104. The signal is the result of the difference between the absorbance exhibited by the sample when the polarization vector is vertical and that when the vector is horizontal. When the sample is subjected to cycles of mechanical stretching and relaxing, as in the present embodiment, the linear dichroic difference of the sample undergoes changes with the result that the static dichroic difference signal due to the polarization modulation is modulated by the dynamic dichroic difference signal caused by mechanical sample modulation.
The rheometer 102 is marketed by the by the Perkin-Elmer Corporation, of 761 Main Avenue, Norwalk, Conn. 06859-0181, U.S.A. as a DMA7 Dynamic Mechanical Analyzer, of which simplified basic details are shown diagrammatically in FIG. 1B. The instrument comprises an electromagnetic drive reminiscent of the well know moving-coil loudspeaker arrangement, in that it comprises a coil of copper wire 102A wound on a cylindrical non-magnetic former 102B attached to a non-magnetic red 102C free to move in the vertical direction only, the coil 102A and a portion of its former 102B being located within the annular gap 102D of a generally cylindrical magnet 102E.
An electrical strain gauge 102F, comprising differential transformer indicated at 102F1, co-operating with soft-iron core 102F2, carried by rod 102C, monitors sample strain. The strain gauge 102F is spaced from the magnet 102E by a cylindrical spacer 102G.
The coil 102A is electromagnetically displaced towards the magnet 102E or away from it with a force and in a direction depending on the intensity and direction, respectively, of a DC current passed through it. If the current is AC, as it is for the purposes of the present embedment, the coil oscillates in sympathy therewith and, therefore, the strain gauge produces a sinusoidal output.
The end of the rod 102C is provided with means for clamping one end of a sample 102H in the form of a strip cut from a thin foil. In FIG. 1B the said means are simplified in order merely to illustrate the function. As shown, they consist of a clamp 102I comprising arms 102I1 and 102I2 that are sprung apart by a small gap when the clamping screw 102I3 is released. The sample 102H is fitted by first inserting one end thereof into the gap and then tightening the screw 102L3 to force the arms 102I1 and 102I2 to close with the sample end compressed therebetween. A clamp similar to clamp 102I is fitted to a plinth 102J, extending from a base 102K of the rheometer 102, and serves the purpose of providing an immovable attachment for the other end of the sample 102H.
The rheometer 102 is capable of subjecting sample 102H to sinusoidal stress changes in the longitudinal direction thereof ranging in frequency from 0.01 Hz to 51 Hz. A constant bias stress may be applied to the sample 102H by passing a constant DC current through the coil 102A. The total stress applied is kept within the elastic limit of the sample.
The magnet 102E, the cylindrical spacer 102G and the strain gauge 102F represent the head parts of the rheometer 102, which parts are firmly supported by the base 102K via an intervening vertical pillar 102L. A controller 102M, shown in front elevation, controls the current passing through coil 102A and receives a sinusoidal strain signal from the strain gauge 102F. In FIG. 1 this reference signal, in phase with sample strain, is passed to the sample and hold unit 109, as the arrow-headed functional route line shows. It is also passed to phase shifter 110 to generate a reference signal in quadrature with sample strain. The importance of these reference signals will be presently appreciated. The electrical connections between the head of rheometer 102 and the controller 102M are provided by conductors (not seen) which extend into cable 102N entering the controller 102M. The reference signal in phase with cyclic sample strain is extended to unit 109 (FIG. 1) via cable 102P.
The rays IB1 and IB2 shown in FIG. 1B represent the marginal rays from the parabolic mirror 22 (FIG. 7 of Imported Patent) passing through planes L1 and L2, whereat the mid planes of polarizer 100 and the PEM 101, respectively, are located. Ray IB3 is the principal ray, of course. The sample 102H is located at the image plane of parabolic mirror 22, whereat an image of the Jaquinot stop 2A (FIG. 7 of Imported Patent) is projected. The lens 103 re-images the Jaquinot stop image onto the MCT detector 104.
The lens 103, a ZnSe lens, is the refractive counterpart of elliptical mirror 24, shown in FIG. 4 of the Imported Patent. The choice of a refractive element avoids the undesirable polarization effects of a reflective element.
The photoconductive MCT detector 104 is a liquid-nitrogen cooled unit marketed by Grasby Infrared Ltd., of Exning Road, Newmarket, Suffolk. Detectors with a poor frequency response in the ultrasonic frequency range are not suitable for DIRLD.
The lock in amplifier 106 is marketed as the LX10 Lock-in Amplifier by Barman Instruments, of Leys Lane, Shipsea, Driffield, East Yorkshire, UK, except that additional passive input filtering has been provided to remove the low frequency unmodulated components in the signal which could otherwise break through into the required output. Additional filtering has also been provided for the output of the synchronous detector 106B to remove residual components at 74 kH and harmonics thereof whilst providing a bandwidth of several kilohertz for the demodulated signal.
The remainder of the units do not require singling out for further description.
In operation, the beam IB, plane polarized in the direction of sample strain by polarizer 100, is polarization modulated by the PEM 101 at an ultrasonic frequency of 74 kHz. If a dichroic sample is fitted to the rheometer 102 but the rheometer 102 is inoperative while OPD scanning is in progress, the output of MCT detector 104 will comprise the compounded emission interferogram of the source and transmission of the sample surmounted by modulated 74 kHz oscillations, the "envelope" of the modulation representing the interferogram of linear dichroism of the sample observed in the course of the OPD scan.
If the rheometer 102 is now activated, the cyclic stretching and relaxing of the sample will cause changes in the differential absorption (i.e. dichroism) of the sample which are due to mechanically induced changes in the dipole moment of the sample molecules. This means that the interferogram of linear dichroism will now be modulated by a signal arising from the co-action between the modulation provided by the interferometer and the sample modulation.
In the embodiment of FIG. 1, the sample modulation range that may be applied is between 1 Hz and 50 Hz, but the DIRLD that is being described could accept a much wider range.
The output of detector 104 reaching the synchronous detector 106B via the amplifier and linearizer 105 and the high pass filter 106A comprises only the modulated 74 kHz signal since the high pass filter 106A holds back the Fourier-frequency signals representing the compounded emission interferogram of the source and transmission of the sample. The synchronous detector 106B, supplied by cable 101F (FIG. 1A) with a 37 kHz signal from the control unit 101E (FIG. 1A) of the PEM transducer 101B (FIG. 1A), via frequency doubler 106C, and variable phase adjust 106D, extracts the modulated "envelope" of the 74 kHz signal. The low pass filter 106E now removes any traces of the 74 kHz signal and harmonics thereof, but its bandwith is sufficient to prevent any impairment of the signal extracted by the synchronous detector 106B.
The output from the lock-in amplifier 106 includes, in the form of a "combined" interferogram, the static (i.e. unmodulated by the rheometer 102) dichroism interferogram of the sample and the dynamic dichroism interferogram associated with sample strain changes that occurred during the time the interferogram was being produced. The term "combined" is intended to convey that the constituent interferograms are not yet resolved.
Data processing of the combined interferogram referred to hereabove now begins, the data involved being handled in three separate channels. Channel 1 is dedicated to the data provided by the combined interferogram. Channel 2 is dedicated to the reference signal in phase with the cyclic sample strain. Channel 3 takes care of the reference signal in quadrature with sample strain.
The in phase reference signal is sampled by sample and hold device 109 and the in quadrature reference signal by sample and hold device 111, and control logic 108 ensures that the said devices are triggered at the same instant in which the combined interferogram signal is sampled in the first channel. The three simultaneously sampled values are admitted to the multiplexer 107, wherein each data point of the sampled combined interferogram is accompanied in the multiplexer 107 by the phase information appertaining to it.
The time coincidence of sampling as stated is fundamentally important in the data processing to follow, aimed at extracting components of the combined interferogram respectively in phase and quadrature with sample strain, thus generating the in phase components interferogram and the in quadrature components interferogram, from which the respective spectra are derived in known manner by the application of Fourier Transform.
Details of how the time coincidence is achieved will now be given. The control logic 108 (FIG. 1) initially sets the multiplexer 107 to select the input from the low pass filter 106E of the lock-in amplifier 106, and places both sample and hold devices 109 and 111 to sampling mode (also known as tracking mode).
On the first pulse of the trigger pulse generator 50 (FIG. 7 of Imported Patent) the sample and hold device 44 is set to hold mode and a conversion cycle on the ADC 45 is started, with the ADC converting the signal from the low pass filter 106E as held by sample and hold device 44. At the same time, sample and hold devices 109 and 111 are also switched to their hold position.
Once the ADC unit 45 has completed its cycle, sample and hold device 44 returns to sampling mode and the multiplexer 107 is switched to select the output from sample and hold device 109.
On the second pulse from the trigger pulse generator 50, the sequence is repeated, except that sample and hold devices 109 and 111 remain in the hold mode throughout, with the ADC unit 45 reading the reference signal held by sample and hold device 109. At the end of this cycle, the multiplexer 107 is switched to select the output from sample and hold device 111.
On the third pulse from the trigger pulse generator 50, the sequence is repeated once more, with sample and hold devices 109 and 111 still in hold mode and the ADC unit 45 reading the other reference signal, held by sample and hold device 111. At the end of this conversion, the initial state is restored, with the multiplexer 107 selecting the output from the low pass filter 106E and all sample and hold devices returned to the sampling mode ready to repeat the complete cycle.
The process as described enables the ADC unit 45, and hence the microprocessor 46, to read from the three signal channels in turn, while the sample and hold devices 109 and 111 ensure that all three are sampled at the same time.
The three analogue signals per data point of the combined interferogram in the multiplexer 107, respectively in first, second and third channel, are read off channel by channel by the ADC unit 45 (FIG. 7 of Imported Patent) and are subsequently stored in the memory of the microprocessor 46 (FIG. 7 of the Imported Patent), whereby at the end of a complete single direction OPD scan a set of three numbers per data point is accumulated, the number from the first channel representing a data point of the combined interferogam; that from the second channel, the corresponding in phase angle of sample strain; and that from the third channel, the corresponding in quadrature angle of sample strain.
At this juncture the sequence of processing steps is best illustrated with reference to the flow chart of FIG. 2, wherein and hereinafter CI stands for "combined interferogram").
After initialization at SA, via microprocessor 46 (FIG. 7 of the Imported Patent) of the FT spectrophotometer of the Imported Patent as modified in accordance with the present embodiment, a single OPD scan is executed at SB by the interferometer of the Imported Patent, and at SC the set of three numbers per data point referred to earlier is accumulated in the memory of the microprocessor 46. In addition, various cross products are calculated from the three sets of data accumulated after each scan and the values added to the corresponding values accumulated from previous scans. Details of the actual parameters accumulated are given below.
Σ I =sum of CI data values
Σ c =sum of in phase reference values
Σ s =sum of in quadrature reference values
Σ c 2 =stun of square of in phase reference values
Σ s 2 =sun of square of in quadrature reference values
Σ cs =sum of product of in phase and in quadrature reference values
Σ Ic =sum of product of CI and in phase reference values
Σ Is =sum of product of CI and in quadrature reference values
At the end of the single scan, a counter is set to 1 at SD, is compared with the number of scans requested above a minimum of 3 and, if S is not equal to X, a further iteration is requested, as indicated by the loop shown. When S=X, the process advances to SE.
At SC additional data, in the form of third and fourth order cross products, were also accumulated for the reference data, this time single values covering all scans and OPD points. From this the amplitude, DC offset and please difference of the two reference signals are calculated by a least squares error fit method. The main accumulated scan data is then normalized at SF for the effects of amplitude and offset of the two reference signals and any phase error in the quadrature reference.
The main processing takes place at SG. It involves finding at each OPD the parameters A,B,C which define the sample modulation dependency of the combined interferogram with the least squares error fit to the observed data. This involves the solution of three simultaneous equations, details of which are given below. ##EQU1##
The coefficients of these equations are the values from the scan data accumulations. The resulting calculated parameters are formed into three new interferograms, corresponding to the average unmodulated value (A), the value in phase with modulation (B) and the value in quadrature with the data (C), which are saved on disk at SH and converted to spectra at SJ using normal FT-IR algorithms at SI. The disk is a hard disk contained in the hard disk unit 58 which has been added to the system of FIG. 7 of the Imported Patent as shown in FIG. 3 of this specification.
The operation indicated at SG is based upon a model which assumes that the con, non interferogram CI is represented by the sum of three components: one in phase with sample modulation, one in quadrature with sample modulation and a constant term, as expressed below:
CI=A+B×cos theta+C×sin theta
where
A is the constant term, i.e. the linear dichroic difference interferogram unaffected by sample modulation;
B is the in phase term and
C is the in quadrature term.
Theta is the phase angle value of the cyclic perturbations.
The object is to find at each OPD point the best fit of the CI data to the model. Since the equation on which the model is based defines an ellipse, what is required is a best fit to an ellipse. This is achieved by finding the least squares fit to an ellipse of the CI data collected from the desired number of OPD scans.
A graphical illustration of the process is shown in FIG. 1C, wherein CI values at each OPD are plotted as the ordinate Y against the in phase signal derived from the rheometer as the abscissa X. As FIG. 3 shows, the shape and orientation of the ellipse is determined by A, B, and C which have been obtained at SG (FIG. 2) in the manner described hereabove.
It is now clear that the best fit process executed by the microprocessor 46 of the Imported Patent, which fundamentally relies on the two hardware generated reference signals, one in phase and the other in quadrature with sample strain, provide the proper co-ordination in time of the interferometric data regardless of the scanning speed of the interferometer or the rate differential between OPD scanning and mechanical sample modulation. The interferometer may therefore be operated up to the high limit of the speed range for which it was designed and the sample modulation frequency can be safely chosen to suit the sample and the nature of the analysis.
The embodiment described is an example of a time-resolved FT spectrophotometer in accordance with the invention which can be used in the continuous fast scanning mode independently of any chosen frequency of the cyclic perturbations, such as sample modulation, up to just above or just below the band of Fourier frequencies.
The foregoing description inherently provides the disclosure of a method of FT optical spectroscopy in accordance with the invention.
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In FT-DIRLD (Dynamic Infra Red Linear Dichroism) apparatus partly represented in FIG. 1, units 100-105, responding to interferometer output IB (indicated elsewhere), cause unit 106 to yield an interferogram combining static and dynamic dichroism interferograms. Reference signals respectively in phase and quadrature with cyclic sample strain are derived from rheometer 102. At each OPD point of predetermined uninterrupted scans, controller 108 routes simultaneously a data point of the combined interferogram and the reference signals to respective channels of multiplexer 107. A microprocessor (shown elsewhere) subsequently performs a best-fit-to-an ellipse sorting of the data and for each OPD derives: A) the value of the interferogram unaffected by sample modulation; B) the corresponding in phase term; and C) the corresponding in quadrature term; furthermore, from the A, B,C data-point series it generates the interferogram of each series and transforms it into a spectrum. DIRLD analysis is achieved asynchronously and in continuous fast scanning.
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BACKGROUND OF THE INVENTION
This invention relates to an eye examining apparatus, and more particularly to an eye examining apparatus for measuring the optical transfer function of an optical system of a patient's eye.
An abnormality detecting apparatus for detecting abnormality in an optical system of a patient's eye caused by opacity of the lens or vitreous body of the patient's eye or the like by detecting the amount of reflected light, utilizing a refraction measurement system for measuring the refraction of a patient's eye, has heretofore been known as an eye examining apparatus.
As a method for examining abnormality in the optical system of an eye, a method has also been proposed or measuring the refraction across any possible diameter of a patient's eye and inferring abnormality in the optical system of the patient's eye from the scattering of these measured values.
In the above-described conventional eye examining apparatus, however, if there is opacity in the common region where both the light beam which enters the retina and the light beam reflected from the retina pass, the light beam reflected from the opacity mixes with the light beam reflected from the retina. As a result, this opacity may not be detected as abnormality in an abnormality detecting system which detects opacity of a body subject to light transmission.
Furthermore, in the method of detecting abnormality of the optical system of an eye, when opacity is generated in the vicinity of the retina of the patient's eye, the opacity has an influence on the refraction in the direction of relevant diameter, but if opacity is generated in the vicinity of the pupil, the light beam to be measured in all diametric directions passes through the opacity, so that there is no scattering of the measured values with respect to each diameter, which inconveniently makes it impossible to detect the opacity.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide an eye examining apparatus which is capable of accurate detection of abnormality in the optical system of a patient's eye which might exist at any position of the eye, thereby solving the above-described problems in the prior art.
It is another object of the invention to provide an eye examining apparatus which is capable of easy measurement of the refraction of a patient's eye.
To achieve this aim, an apparatus according to the invention is composed of a target projecting system for projecting a target image to be measured on a retina; focalizing means for detecting the focus of the target to be measured and focalizing it on the retina; and an optical transfer function measuring system for detecting the contrast of the target image to be measured which is focalized on the retina and thereby measuring the optical transfer function of a patient's eye.
In one embodiment of the invention, the target projecting system includes a means for rotating a target image to be meaured around an optical axis.
Another embodiment of the invention includes a comparing means for comparing the above-described optical transfer function with that of a normal eye.
The above and other objects, features and advantages of the present invention will become clear from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an embodiment of an eye examining apparatus according to the present invention;
FIG. 2 shows the optical system of a refracting device;
FIG. 3 is an exploded perspective view of a target plate;
FIG. 4 is a perspective view of an oculogyric target;
FIGS. 5A-5K are explanatory views of a method of calculating the optical transfer function; and
FIG. 6 schematically shows one example of a pattern for measuring the optical transfer function.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of an eye examining apparatus according to the invention will now be described with reference to the accompanying drawings. A first embodiment of an eye examining apparatus includes, as is shown in the block diagram of FIG. 1, an optical system 2 having an optical projecting system for projecting an image of a target plate for measuring optical transfer function on the retina E R of a patient's eye, and an optical measurement system for detecting the state of the image of the target plate formed on the retina E R . The state of the image of the target plate which is detected by the optical measurement system is converted into a picture signal by camera tube and is output.
The optical system 2 is connected to a monitor TV 4 to which the picture signal is output, and the monitor TV 4 displays the image of the target plate formed on the retina E R together with the measured result which will be described later.
The electric system to which the output of the optical system 2 is input has an arithmetic circuit 8 for deciding between abnormality and normality in the optical system of the patient's eye by calculating the optical transfer function from the picture signal output from the optical system 2 and for calculating the refraction, a first memory 10 which is connected to the arithmetic circuit 8 and temporarily stores the picture signal, a second memory 12 which is also connected to the arithmetic circuit 8 and stores the optical transfer function of a normal eye, a first interface 14 which is connected to the optical system 2, the first memory 10 and the arithmetic circuit 8, a second interface 16 which is connected to the optical system 2 and the arithmetic circuit 8, and a third interface 18 which is connected to the arithmetic circuit 8 for converting the output of the arithmetic circuit 8 into a print signal.
A printer 20 for printing the output of the measured results is connected to the third interface 18.
In the above-described structure, the image of the target plate which is formed on the retina E R by the optical projecting system is projected on the camera tube and converted into a picture signal by the optical measurement system. The picture signal is input to the monitor TV 4, which displays the image of the target plate on the retina of the patient's eye. On the other hand, the picture signal is input to and stored by the first memory 10 through the first interface 14, and thereafter is input to the arithmetic circuit 8. The arithmetic circuit 8 calculates the optical transfer function from the picture signal, and decides between aberration and normality in the optical system of the patient's eye by comparing the calculated optical transfer function of the patient's eye with that of a normal eye, the result being displayed by the monitor TV 4 and printed by the printer 20.
Information about the refraction of the eye is input to the arithmetic circuit 8 through the interface 16, where the sphericity, the axis of astigmatism and the astigmatism are calculated, the results being also displayed by the monitor TV 4 and printed by the printer 20.
The optical system 2 includes, as is shown in FIG. 2, an optical projecting system 30, an optical measurement system 32 and an optical fixation system 34. The optical projecting system 30 is composed of a light source 49, a condenser lens 42, an infrared-transmissing mirror 48 which is obliquely disposed before the condenser lens 42 (facing a patient's eye E) in order to take out the visible light which is to be the light beam of the light source in the optical locking system 34, a target plate 50, a projecting lens 52, a pentagonal prism 54 for refracting an optical axis 53 of the optical projecting system 30 through 90 degrees, and a stop plate 58 with rectangular openings 56 disposed away from the optical axis 53. The stop plate 58 is arranged so that it is conjugate with the light source 40 with respect to the projecting lens 52.
The optical projecting system 30 further includes a direct vision prism 64 with a through hole 62 the axis of which coincides with the optical axis 60, an image rotator 66, and an objective lens 68, all three being arranged on the optical axis 60 of the optical measurement system 32. The stop plate 58 is arranged such that it is conjugate with the pupil of a patient's eye with respect to the objective lens 68. The target plate 50 is located so that it is conjugate to the retina E R of a patient's eye in relation to the projecting lens 53 and the objective lens 68.
The target plate 50 is, as is shown in FIG. 3, composed of a slit plate 70, and a prism plate 72 which is adjacent to the slit plate 70 and is disposed facing the patient's eye E. The slit plate 70 is composed of slits 74 for measuring the refraction and slits 76 for measuring the axis of astigmatism which are provided orthogonally to the slits 74, and a pattern 78 for the measuring optical transfer function which is divided into a section which transmits infrared light and a section which is opaque to it by a borderline 77 in the radial direction. The prism plate 72 is composed of a infrared-transmissing plate member 81, to which four prisms 85 are attached to as is shown in FIG. 3. The prisms 85 refract part of the light beam which has passed through the slits 74 for measuring the refraction and the slits 76 for measuring the axis of astigmatism in the horizontal direction viewed in FIG. 3.
In the optical projecting system 30, the light beam projected on the target plate 50 passes through the peripheral portion 56 of the pupil of the patient's eye E P and reaches the retina E R . When the projected light beam is focalized on the retina E R , the same pattern as that of slit plate 70 is formed thereon. When it is not focalized, the total composite image becomes unfocussed and each image of the slits 74 used for measuring the refraction is split into two. The split portions are displaced in the direction perpendicular to the slits 74 to form images.
Similarly, when the patient's eye has some astigmatism, and the direction of the slit images formed by the slits 76 for measuring the axis of astigmatism on the retina E R and the axes of astigmatism of the patient's eye do not coincident, each image of the slits 76 for measuring the axis of astigmatism is split into two, and the split parts are displaced in the direction perpendicular to the slits 76 to form images. On the other hand, when the direction of the slit images formed by the slits 76 for measuring the axis of astigmatism on the retina E R coincides with one of the axes of astigmatism of the patient's eye, the images of the slits 76 for measuring the axis of astigmatism are formed in alignment.
When the image rotator 66 is rotated, the composite image of the slit plate 70 on the retina E R rotates around the optical axis of the eye, so that the direction of the slits 76 for measuring the axis of astigmatism and the direction of the borderline 77 of the pattern 78 for measuring the optical transfer function can be made to agree with the axis of astigmatism.
The optical measurement system 32 is composed of the objective lens 68, the image rotator 66 and three image-forming lenses 80, 82 and 83. The target plate 50 in combination with the image-forming lens 82 moves along the corresponding optical axes. A camera tube 84 is disposed behind the image-forming lens 83 so that the retina E R and a light-receiving surface 86 of the camera tube 84 are conjugate with respect to the objective lens 68 and the image-forming lenses 80, 82 and 83.
In the optical measurement system 32, the light beam to be measured, which has formed the composite image of the slit plate 70 on the retina E R and is reflected therefrom, passes through the through hole 62 of the prism 64 and reaches the light receiving-surface 86. Although the image of the slit plate on the retina E R is rotated by the rotation of the image rotator 66, since the light beam to be measured is rotated by the same degrees in the opposite direction by the image rotator 66, the image of the slit plate which is constantly directed in a predetermined direction is formed on the light-receiving surface 86.
The fixation system 34 for fix visual line is composed of a mirror 90 for reflecting the light beam reflected from the infrared-transmissing mirror 48, an fixation target 92, a projecting lens 94, two mirrors 96 and 98, and an infrared-trans-mitting visible reflex mirror 99 which is provided obliquely between the image rotator 66 and the objective lens 68.
The fixation target 92 is constructed so as to have only a center point 92' and a ring 92" as transmission parts, as is shown in FIG. 4, and is placed so as to have a slightly positive diopter from the position at which the fixation target 92 is conjugate with the retina E R with respect to the objective lens 68 and the projecting lens 94, in order to fogging the eye being examined.
The process of measuring by the optical system 2 will next be described. The image rotator 66, and hence the images of the slit plate on the retina E R , is first rotated until the images of the slits for measuring the axis of astigmatism are aligned, while observing the composite image of the slit plate displayed on the monitor TV. This operation enables the alignment of the direction of the borderline 77 of the pattern 78 for measuring the optial transfer function with one of the axes of astigmatism.
The target plate 50 is next moved along the optical axis 53 until the images of the slits for measuring the refraction are in alignment. This operation focalizes the composite image of the slit plate 70 and forms an image on the retina E R .
The image rotator 66 is next rotated in order to turn the images of the slit plate 70 on the retina E R through 90 degrees, and the target plate 50 is further moved along the optical axis 53 until the images of the slits for measuring the refraction are in alignment. This operation aligns the direction of the borderline 77 with the other axis of astigmatism, and focalizes the composite image of the split plate 70 on the retina E R . It is known to those who are skilled in the art that the position of the target plate 50 and the rotation angle of the image rotator 66 in these operations can be electrically detected in at least three diametric direction and, on the basis of these detection signals, the sphericity, the astigmatism, and the axis of astigmatism can be calculated, so an explanation thereof will be omitted.
The abnormality in the optical system of the patient's eye is next detected from the picture signal of the image of the pattern 78 for measuring the optical transfer function on the retina, using the following method, while the direction of the borderline 77 of the pattern 78 for measuring the optical transfer function is in agreement with one axis of astigmatism and the images on the slit plate 70 are focalized on the retina E R .
The slit plate 70 is provided with the pattern 78 for measuring the optical transfer function at its lower portion, as is shown in FIG. 5A, and the following edge function 0(X) of the borderline 77 is a step function which denotes a section which transmits infrared light and a section which is opaque to it, as is shown in FIG. 5B: ##EQU1##
On the other hand, in the images of the pattern 78 for measuring the optical transfer function on the retina E R , the borderline 77 becomes unclear, as is shown in FIG. 5C, and its edge function e(X) is as shown in FIG. 5D. The edge function e(X) can be obtained by averaging the picture signals of a plurality of scanning lines from the camera tube 84. The line intensity spread function h(X) of the optical system of the patient's eye is obtained by differentiating the edge function e(X), as is shown in FIGS. 5(E) and 5(F), which is expressed by: ##EQU2## in which the following relationship holds:
e(X)=0(X)*h(X)
wherein * represents convolution. The line intensity spread function h(X) obtained in this way is subjected to Fourier transform, as is shown in FIGS. 5G and 5F, and, by extractng the square root thereof, the optical transfer function H(u) which denotes the spectral intensity H(u) in the spatial frequency U of the optical system of the patient's eye can be obtained. The effects of the optical system and processing system outside the patient's eye are negligibly small, and so can be ignored.
When there is opacity in the optical systen of the patient's eye, the horderline 77 of the pattern 78 for measuring the optical transfer function becomes unclear, and the spectral intensity, namely the optical transfer function H(u), drops in the high-frequency range. The average optical transfer function Ho(u) of a normal eye is stored in the second memory 12 (FIG. 5I), and the value of {Ho(u)-H(u)} at a specific frequency, for example, that for U=fa, is calculated and compared with this function Ho(u) (FIG. 5J). When it exceeds a predetermined value, it is determined that the optical system of the patient's eye has abnormality and the result is output (FIG. 5H).
A second embodiment of the present invention is so designed as to automatically measure the sphericitiy, the astigmatism, and the axis of astigmatism and adjust the direction of the borderline of a pattern for measuring the optical transfer function. That is, the distance between the two split slit images which are separated from each other in the direction perpendicular to the slits are detected on the basis of the picture signals from the camera tube 84, a target plate 50 to be measured is automatically moved until the distance obtained by the detection signal is zero, and the degree of refraction in this diametric direction can be obtained from the amount of movement of the target plate 50. The measurement of the degree of refraction is conducted with respect to three diametric directions, and the sphericity, the astigmatism and the axis of astigmatism are calculated from these measurement results. Furthermore, on the basis of the calculation results, the borderline of the pattern for measuring the optical transfer function can be automatically made to agree with the axis of astigmatism.
In a third embodiment of the invention, the pattern for measuring the optical transfer function in the first embodiment is composed of a slit which is provided at the same position as the borderline. This embodiment enables the line intensity spread function H(X) to be obtained directly from the composite image on the retina E R in consideration of the width of the slit.
A fourth embodiment of the present invention is so composed that the edge function e(X) can be obtained by projecting the image of the pattern for measuring the optical transfer function on the retina onto a photoelectric transducer such as a two-dimendional array sensor, a one-dimensional array sensor, or a sensor utilizing mechanical scanning.
In a fifth embodiment of the present invention, the pattern for measuring the optical transfer function of the first embodiment is not provided, and the target images for measuring the degree of refraction and the axis of astigmatism are also used for measuring the optical transfer function.
The pattern for measuring the optical transfer function in a sixth embodiment of the present invention is composed of a rectangular chart or a sine-wave chart in which frequency changes continuously, as is shown in FIG. 6. The use of this chart enables the frequency transfer function at each frequency of the optical system of the eye to be obtained without the need for a frequency analysis step.
As described above, the eye examining apparatus according to the present invention can advantageously measure the optical transfer function of the optical system of a patient's eye in the state wherein the refraction of the eye being examined is corrected and a target image to be measured is focalized by a means for focalizing the target image to be measured, so that the presence of opacity, cataracts, irregular astigmatism can be accurately detected at any position of the optical system of the patient's eye. The present invention is also advantageous in that the refraction of the eye being examined can be easily measured from the amount of adjustment of the above-described focalizing means.
While there has been described what are at present considered to be preferred embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.
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An eye examining apparatus is disclosed which is capable of the accurate detection of any abnormality in the optical system of a patient's eye which might exist at any position of the eye, and also which is capable of providing easy measurement of the degree of refraction of the patient's eye. The apparatus comprises a target projecting system for projecting onto a retina a target image to be measured; focalizing means for detecting the focus of the target to be measured and for focalizing it on the retina; and an optical transfer function measuring system for detecting the contrast of the target image to be measured, which is focalized on the retina, and thereby measuring the optical transfer function of the patient's eye.
The apparatus may further comprise means for comparing the measured optical transfer function with that of a normal eye, and the target projecting system may include a means for rotating the target image to be measured around an optical axis.
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BACKGROUND OF THE INVENTION
[0001] A. Field of the Invention
[0002] The present invention generally relates to a device for collecting pet waste, objects, debris, or other material. More specifically, the present invention relates to a vacuum-actuated device.
[0003] B. Description of the Related Art
[0004] Commonly, local laws, ordinances, or homeowners' associations require pet owners to remove and dispose of pet waste immediately or very soon after it is deposited. Even if a pet owner is not required by rule or regulation to remove pet waste, many pet owners prefer to remove it to maintain the cleanliness of their lawns, neighborhoods, and environment. Typically, pet waste is removed by using a bag, either with or without a shovel or scoop, to collect the waste. This activity requires the user to bend or stoop. This method is unpleasant and can result in the inadvertent transfer of waste to a user, which can be hazardous to the person's health. Further, because a plastic bag is often used, disposal can be environmentally detrimental.
[0005] Typically, devices for waste collection include shovels, scoops, bags, and other devices that require the user to have relatively good mobility and strength. Motorized devices are often heavy and/or bulky, difficult to transfer long distances, and require the user to have relatively good strength and flexibility. Even if the motorized devices are lighter in weight, each has its limitations. Commonly, motorized devices can be soiled during use and must be cleaned to eliminate undesirable odors and potential health risks from waste residue. Individuals that have arthritis, back pain, degenerative disc disease, coordination problems, poor eyesight, or other nerve or muscular problems that limit mobility can find cleaning up pet waste, debris, or other material by using such devices to be a particularly difficult task.
[0006] U.S. Pat. No. 7,984,530 discloses a pet waste vacuum system that can use disposable liners; however, the apparatus must be partially disassembled to remove the liner and waste, which makes the task less pleasant and difficult for those having limited mobility, flexibility, or eyesight.
SUMMARY OF THE INVENTION
[0007] Individuals having diminished mobility or strength, or visual impairment(s) can find daily tasks challenging. Individuals attempting to multi-task, e.g hold onto a pet's leash and collect the pet's waste, may find that their range of motion is inhibited. The present invention provides compositions and methods relating to an improved handheld, portable vacuum. The invention provides a relatively lightweight vacuum that can be operated with one hand and is designed to collect a variety of objects or solid animal waste. The vacuum is designed so that a user does not need to bend, reach, or stoop excessively. Reducing the need to bend, reach, or stoop is useful to individuals having limited mobility, diminished strength, or impaired eyesight.
[0008] The vacuum is designed so that when animal waste is collected the device and user have little or no direct, physical contact with the waste during collection and disposal. Reducing exposure to animal waste can help to reduce health risks and make a necessary task less unpleasant.
[0009] Advantageously, the same vacuum device can be used to collect objects, particularly small or lightweight objects, without excessive stooping, reaching, or bending.
[0010] Thus, the devices of the invention are particularly suitable for use by individuals having limited mobility, diminished strength, or impaired eyesight such as the aged, blind, or chronically ill (e.g. diabetics).
[0011] The invention provides a portable vacuum device comprising a handle, a motor having a fan, and a tube. The motor is housed in the handle. The tube is attached to the handle, and the tube includes an intake port that is located distally to the handle, a first filter guard, and a collection compartment. The collection compartment is in the half of the tube nearest to the intake port, more preferably the collection compartment is located in the third, and even more preferably the quarter, of the tube nearest to the intake port. The first filter guard is located between the first collection compartment and the handle. The vacuum device is operable with one hand.
[0012] The motor includes a battery or an electric cord, preferably the motor operates by using one or more batteries. One or more fans may be included in or adjacent to the motor.
[0013] Preferred embodiments of the invention include a second filter guard that is located in the half of the tube most adjacent to the handle.
[0014] Portable vacuum devices of the invention include either a telescoping tube or a tube that does not fold or collapse.
[0015] Embodiments of the invention include a tube that has an attachment area for a collection bag that fits into the collection compartment. The attachment area is located on the exterior of the tube that is adjacent to the intake port, and the attachment area has a circumference that is greater than the circumference of the exterior portion of the tube adjacent to the attachment area. Preferably, the attachment area is curled, winged, pronged, or otherwise folded away from the input port such that a collection bag can cover or overlap the attachment area, and the bag will remain in place when vacuuming. The attachment area may include tacky material, adhesive, hook(s), prong(s), or other means suitable for keeping a bag in place during vacuum operation.
[0016] Portable vacuum devices of the invention can further include a means to collect objects without operating a vacuum. Such embodiments have a means that substantially surrounds the exterior tube adjacent to the intake port, and the means comprises a tacky material, adhesive, bristle, fiber, brush, magnet, or any combination thereof
[0017] Preferably, handles of the vacuum devices include an operating mechanism that is an on/off mechanism, a reverse mechanism, a light switch, or any combination thereof. Handles may include a scent compartment, a wrist strap, reflector, light, or any combination thereof.
[0018] Portable vacuum devices of the invention may include a tube that has a scent compartment, reflector, light, or any combination thereof.
[0019] Certain embodiments of the invention further comprise a floor attachment that has an intake opening, a second collection compartment, and a connector space to which the distal end of the tube (i.e. the end of the tube having the intake port) attaches such that during operation of the motor air flows through the tube and the floor attachment such that a pressure change occurs.
[0020] Preferably, the floor attachment includes an opener to access the second collection compartment. The floor attachment may also include a wheel, a roller, a connector for a carrying means (e.g. a strap), a reflector, a scent compartment, or any combination thereof.
[0021] Certain floor attachments of the invention are particularly intended to be useful for the collection of solid pet waste. Preferably, these floor attachments are configured so that a collection bag can be fitted into the floor attachment and extended through the intake opening and over a portion of the exterior of the floor attachment to reduce, or even eliminate, physical contact between the vacuum device and the pet waste.
[0022] Preferred floor attachments are configured so that a front portion of each side of the floor attachment is broader than an adjacent rear portion of each side of the floor attachment and together the broader front portions of the sides form a connecting region for a collection bag that inserts into the collection compartment of the floor attachment.
[0023] Preferred floor attachments of the invention further include a molded depression into which the tube can at least partially rest when the device is not in use. If a telescoping tube is present, then preferably the molded depression accommodates the telescoped tube in a collapsed position, preferably a fully collapsed position so that vacuum devices of the invention can be reduced in size for storage, carrying, or shipping.
[0024] The invention provides a method of collecting objects using a vacuum device.
[0025] The invention also provides a method of collecting solid animal waste comprising using a vacuum device with a collection bag. Those of skill in the art will recognize that the embodiments of the invention described as being suitable for the collection of solid pet waste may also be useful for the collection and disposal of many other solid, or semi-solid, wastes with which it is desirable to avoid physical contact.
[0026] Certain embodiments of the invention operate by using a motor having a battery(ies). In other embodiments the motor may be operated with an electrical cord. Preferred motors have one or more fans. The motor may be located in multiple positions, such as either along a side, at or near the bottom of the device, or at or near the top of the device. It is preferred that the motor is located adjacent to, or more preferably within, the handle area. If the motor is battery-operated, then preferably the battery(ies) is located in or adjacent to the handle area. If the motor is operated with an electrical cord, then preferably the cord is retractable and located in or adjacent to the handle area. Those of skill in the art will recognize that a wide variety of motors suitable for use in the invention are available. It is expected that any suitable motor, battery, or cord may be used in the invention.
[0027] Embodiments of the invention may be vented so that air circulates within or through the device. Preferably, air circulates within or through at least the compartment in which material is collected. This compartment may be either a collection compartment or a waste compartment containing a bag to hold collected waste.
[0028] When the motor is located within the handle area, preferably the handle is vented. Either single or multiple vents may be present in the handle. The number of vents present will, in part, be determined by the size of the vent(s), the amount of air circulation that is required for a motor and/or fan to operate, and the amount of air circulation required to create suction to collect material into the device's compartment. Those of skill in the art will be familiar with the principles governing vacuum technology and how to determine the number and size of the vents.
[0029] Advantageously, certain embodiments of the invention that are useful for the vacuum collection of objects are designed so that when the vacuum is not operating, then the collected objects are retained within the device. These embodiments include a tube closure, such as a flap, fold, or other suitable means known in the art, that attaches to the tube and is adjacent to the intake port. When the vacuum device is not in operation, the tube closure covers the intake port. When a vacuum force is applied, or the user operates an opener-closer, then the tube closure is held or forced against the interior of the tube such that objects can be sucked into the collection compartment. When the vacuum force is removed, or the user operates the opener-closer, then the tube closure returns to its resting position and covers the intake port such that collected objects stay in the collection compartment. Alternatively or additionally, a bag can be placed in the collection compartment to hold vacuumed objects. A bag having vacuumed objects either may be removed from the device or left in the compartment and portions of the bag that are exterior to the collection compartment can be tucked into the compartment.
[0030] When the user wishes to remove the objects, the user can operate a switch, button, lever, or other release mechanism on, contiguous with, adjacent to, or near the handle to open the device, or preferably the compartment containing the object, and either allow gravity to cause the objects to empty, or drop, from the collection compartment, or alternatively, cause the air flow in the device to reverse and forcibly expel the objects. By locating a release mechanism on, contiguous with, adjacent to, or near the handle area, the user has the opportunity to operate the device with a single hand. Alternatively or additionally, a release mechanism may be located in the distal half of the device closer to the collection compartment.
[0031] Embodiments of the invention may include a means to collect objects without operating the vacuum. Preferably, the means is attached to the device near or adjacent to the opening through which objects move into a collection compartment of the device. The means may be a tacky material, adhesive, bristle, fiber, brush, magnet, or combination thereof Preferably, the means includes one or more magnets so that a user may easily separate metallic and non-metallic objects. The means may be any shape or size suitable for attachment near or adjacent to the collection opening. Most preferably, the means includes one or more magnets immediately adjacent to and substantially surrounding the collection opening.
[0032] Preferred embodiments of the invention are made primarily of plastic or other lightweight materials. Those of skill in the art will be familiar with the wide variety of materials that are suitable for the manufacture of various components of the invention. Those of skill in the art will also appreciate that preferred embodiments of the invention will be relatively lightweight. More specifically, embodiments of the invention are expected to weigh less than 15 lbs., preferred embodiments weigh less than 10 lbs., more preferably less than 9, 8, 7, or 6 lbs., and most preferably less than 5 lbs.
[0033] Before describing the present invention in detail, it is to be understood that this invention is not limited to the exemplary embodiments. Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. It is also to be understood that the terminology used is for the purpose of describing particular embodiments of the invention and is not intended to be limiting. It must be noted that, as used in this specification and the attached claims, the singular forms “a”, “an” and “the” include plural referents unless the content clearly dictates otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[0035] FIG. 1 . shows a diagram of one embodiment of the invention with an exemplary arrangement for a waste filter bag.
[0036] FIG. 2 shows a diagram of another embodiment of the invention with an exemplary arrangement for a waste filter bag.
[0037] FIG. 3 shows a diagram of an embodiment of the invention that includes a floor attachment having a waste compartment.
[0038] FIG. 4 illustrates an embodiment of the invention with a floor attachment in position for storage, shipping, or carrying.
[0039] FIG. 5 illustrates further details of a floor attachment.
DETAILED DESCRIPTION
[0040] The invention provides a relatively lightweight, handheld vacuum especially designed to pick up solid animal waste or objects, preferably small objects such as pins, fasteners, buttons, paper, hearing aids, lightweight objects of various size, etc., without requiring that the user unduly bend, reach, or stoop to operate the vacuum. Objects that the invention can collect may be either metallic or non-metallic. Advantageously, the vacuum is designed so that it can be operated with one hand. Some embodiments of the invention can be compacted for storage, shipping, carrying, or easier transport.
[0041] Embodiments of the invention that are particularly suitable for collection of solid animal waste are advantageously designed so that both the device and the user's physical contact with the animal waste is reduced, or even eliminated. By reducing, or even eliminating, physical contact with animal excrement little or no cleaning of the device or user are required after use.
[0042] When the invention is used to collect objects a bag may or may not be used. Those of skill in the art will appreciate that when a user is using a device of the invention to collect dust, debris, or other material intended for disposal, then a user may prefer to use the device with a bag. Such a bag may be made of plastic, paper, cloth, filter material, or any combination thereof. An environmentally safe bag is preferred. Alternatively, a user may prefer to collect material, e.g. buttons, screws, coins, etc., without a bag.
[0043] FIGS. 1 and 2 illustrate two embodiments of the invention. FIG. 1 shows an embodiment in which the vacuum includes a tube ( 11 ) that is telescopic and may be retracted or collapsed when the vacuum is not in use. FIG. 2 shows a device having a tube ( 11 ) that is not retractable or collapsible. During vacuum operation, air flows from the distal opening of the tube ( 11 ) (i.e an intake port) towards the handle ( 1 ) with enough force to create sufficient suction to collect material into the tube ( 11 ). Those of skill in the art will be familiar with the principles of vacuum technology and understand that the length of the tube, the size of the intake port, the force generated by the motor will, and rate of air flow will all effect the amount of suction that is created by the device.
[0044] To prevent collected material from travelling the entire length of the tube ( 11 ) towards the handle ( 1 ), one or more filter guards ( 10 ) are present in the tube ( 11 ). Preferably at least one filter guard ( 10 ) is located, relative to the handle ( 1 ), in the distal half, third, or even the most distal quarter of the tube ( 11 ). And, preferably another filter guard ( 10 ) is located in the half, third, or even the quarter of the tube ( 11 ) most adjacent to the handle ( 1 ). When not in use, the distal end of the tube ( 11 ) may be covered by an end cap.
[0045] When a bag is used in an embodiment similar to either FIG. 1 or 2 , then the bag ( 13 ) is placed in a waste compartment ( 12 ) at the most distal portion of the tube ( 11 ) relative to the handle ( 1 ). Preferably, a portion of the bag ( 13 ) overlaps onto the exterior of the distal end of the tube ( 11 ) so that material, such as animal waste, does not contact the device during use. It is also preferred that the bag extends sufficiently over the exterior of the distal portion of the tube so that the user can reduce, or even eliminate, contact with collected material, such as animal waste, when removing the bag from the device. Preferred bags are environmentally safe and biodegradable. Preferred bags also have a fastener, such as elastic or other flexible material, that acts to hold the bag in place during vacuum operation. Such fasteners also may act to close a filled bag. Those of skill in the art will be familiar with the many suitable means for closing a bag. Preferred fasteners are pull tabs or have sticky ends. Preferred bags allow air to pass through them.
[0046] The exterior of the distal end of the tube ( 11 ) is shaped to help fix in place the portion of the bag ( 13 ) that extends over the exterior of the tube ( 11 ). The exterior of the distal end of the tube may be shaped in a variety of ways to help the bag to stay in place. For example, the exterior of the distal end of the tube may be curled, have flaps or wings, folded outward, or otherwise shaped or molded so that when a bag overlaps the shaped or molded area, then the bag is less able to slip off of the tube as compared to a tube lacking such shaping or molding.
[0047] Adjacent to the filter guard ( 10 ) in the tube ( 11 ) most proximal (i.e. nearest) to the handle ( 1 ) is a scent compartment ( 15 ). Preferably, the scent compartment is adjacent to, or more preferably within the handle ( 1 ). The scent compartment ( 15 ) may contain any variety of materials that are useful for reducing offensive odors that are often associated with pet waste. Preferably, the material used to control odors is lightweight and environmentally safe. Optionally, an opening (not shown) in the tube ( 11 ), handle ( 1 ), or preferably the scent compartment ( 15 ) provides access to the material used to control odor so that it can be replaced as desired.
[0048] So that a user can operate the vacuum with one hand, operating mechanisms for the vacuum are located near, in, or on the handle area. An exemplary arrangement of the operating mechanisms is shown in FIGS. 1 and 2 . Those of skill in the art will understand that many different arrangements of the operating mechanisms can be made. Preferred arrangements are those that are easy for multiple different users to operate. For example, an on/off switch or button ( 3 ), light switch ( 4 ) to operate a light ( 7 ), and reverse switch or button ( 5 ) may be located on an upper, bottom, or side surface of the handle ( 1 ). The operating mechanisms may be adjacent to each other or separated onto different surfaces of the handle ( 1 ). Preferably, the light ( 7 ) is an LED light that operates in the visible light range so that a user can collect material in dim light or in the dark.
[0049] Optionally, a wrist strap ( 8 ) may be attached to the handle ( 1 ) for easier carrying. Either in addition to or in place of a wrist strap, a magnet, clip, or hook ( 9 ) may be on the side of the handle ( 1 ) so that device can be easily stored or carried (e.g. on a wheelchair, walker, or in a closet). Optionally, one or more reflectors ( 14 ) may be present on the side(s) of the handle ( 1 ) or tube ( 11 ) so that the vacuum may be operated with greater safety at night. One or more reflectors ( 14 ) may be placed on the distal portion of the tube ( 11 ) so that a user may more easily identify the opening to the waste compartment ( 12 ).
[0050] The vacuum operates by using a motor having a battery(ies) or an electrical cord.
[0051] While the motor may be located within the device in multiple positions, such as either along a side of the tube ( 11 ), or at or near the bottom or top of the device, it is preferred that the motor is located within the handle ( 1 ) so that the device's weight is better balanced for the user. While the motor is not shown in the accompanying figures, the preferred region ( 2 ) of the handle ( 1 ) within which the motor is placed is identified. If the motor is battery-operated, then preferably the battery(ies) is located in or adjacent to the handle ( 1 ), most preferably the battery(ies) is located in the preferred region ( 2 ) of the handle ( 1 ). If the motor is operated with an electrical cord, then preferably the cord is retractable and located in the preferred region ( 2 ) of the handle ( 1 ) or adjacent to it. Preferably, one or more vents ( 6 ) are located near the motor. The motor may include a fan (not shown).
[0052] The bag ( 13 ) can be composed of any suitable material(s). Preferably, the bag ( 13 ) is environmentally safe, such as a paper bag. Preferred bags ( 13 ) are composed at least partially of paper, other filter material, or a combination thereof so that when the vacuum is operated air can flow through the bag and into the tube ( 11 ). One or more air vents may be located along the tube near the waste compartment or near the motor. Exemplary vents ( 6 ) are shown near the top of the device in the handle area in FIGS. 1-3 .
[0053] A third embodiment of the invention is illustrated in the FIGS. 3-5 . This embodiment includes the features of the other described embodiments of the invention and some additional features. Specifically, this embodiment allows the user to reconfigure a handheld vacuum into a floor vacuum by adding a floor attachment. The reconfigured vacuum is suitable for collecting material, preferably lightweight material such as dust, dirt, small debris, or objects, preferably small objects such as pins, fasteners, buttons, stamps, hearing aids, and other lightweight objects of various size.
[0054] FIG. 3 illustrates the invention reconfigured into a floor vacuum. The most distal end of the tube ( 11 ) attaches to the floor attachment at approximately either connecting position ( 26 ) (see FIGS. 3 and 5 ). Preferably, the tube ( 11 ) may insert, snap, or twist into a connecting position ( 26 ). Skilled artisans will understand that the tube ( 11 ) can placed into a connecting position ( 26 ) through any number of readily available means.
[0055] Preferably, the floor attachment includes one or more lights ( 25 ) on or near the front of the floor attachment. Optionally, one or more lights (not shown) may be located along the top or sides of the floor attachment.
[0056] Material is collected through an opening ( 18 ) that is located on the front side of the floor attachment and adjacent to a floor or surface on which the attachment is resting. The opening ( 18 ) may extend partially onto the bottom surface of the floor attachment. The specific location and shape of the opening ( 18 ) may be varied somewhat so that a floor attachment may be especially designed to pick up particular types of materials.
[0057] Vacuumed material, such as waste or an object, is collected in a waste compartment ( 12 ) located inside the floor attachment (see FIGS. 4 and 5 , dotted line). The waste compartment is accessed by removing or opening the top or lid ( 17 ) of the floor attachment with an opener ( 21 ). Preferably, the opener ( 21 ) is located on a front portion of the lid ( 17 ). The opener ( 21 ) is a switch, or more preferably a button, that can be easily operated with the user's foot, hand, or finger(s) to open the lid ( 17 ). The lid ( 17 ) may be held in place by molded tabs, strips, or other similar molded indentations, or one or more hinges. If the lid ( 17 ) is hinged then one or more hinges ( 23 ) may be located either on a side, or preferably along the back, of the floor attachment. The lid ( 17 ) can be closed by simply pressing it back into position for use.
[0058] In some embodiments of the invention a bag may be placed in the compartment to contain collected material. The bag may be made of any suitable material such as plastic, cloth, paper, or any combination of such materials. Preferably, the bag is paper, and more preferably, the bag is composed of a filter paper so that air can flow through the bag. Alternatively, a user may use the floor vacuum without a bag in the compartment. When a bag ( 13 ) is placed in the compartment ( 12 ), preferably the bag ( 13 ) extends outside of the compartment and over a portion of the front of the floor attachment. More preferably, the front of the floor attachment is configured to be wider along its lateral edges relative to the rest of the floor attachment so that the bag ( 13 ) extends over the lateral edges and better protects the device from contacting waste or other material (see FIGS. 4 and 5 ).
[0059] Optionally, the floor attachment may have a wheel(s) or roller(s) ( 20 ), or a connector ( 19 ) for a shoulder strap or other carrying means. In addition, the floor attachment may have one or more safety reflectors ( 14 ) located along its top, side(s), front, and/or back. One or more scent compartments ( 15 ) may also be present on the floor attachment. If a scent compartment is present then preferably a means of opening the scent compartment is included so that the material used to control or mask odor can be replaced. An end cap ( 16 ) may be included to cover the distal end of the tube ( 11 ).
[0060] When not in use, the floor attachment includes a molded depression ( 22 ) into which the tube ( 11 ) can be folded or collapsed so that the vacuum takes up less space when stored or carried. Preferably, when the tube ( 11 ) is telescopic, the tube ( 11 ) can be reduced in size and fit into the molded depression ( 22 ). One configuration of the folded vacuum is shown in FIG. 4 . Advantageously, when the collapsed tube ( 11 ) is folded into the floor attachment, the size of the entire device is greatly reduced so that it can be easily carried, shipped, or stored.
[0061] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs at the time of filing. The meaning and scope of terms should be clear; however, in the event of any latent ambiguity, definitions provided herein take precedent over any dictionary or extrinsic definition. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular. Herein, the use of “or” means “and/or” unless stated otherwise. Furthermore, the use of the term “including”, as well as other forms such as “includes” and “included” is not limiting. All patents and publications referred to herein are incorporated by reference herein.
[0062] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs at the time of filing. All patents and publications referred to herein are incorporated by reference herein.
[0063] All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the following claims.
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The present invention relates to a lightweight, portable vacuum that can be operated with a single hand. The invention provides improved means of collecting small objects, pet waste, dust, dirt, or other small debris without requiring excessive bending or stooping by the user. Advantageously, the invention provides improvements that reduce or potentially eliminate the user's contact with pet waste or other potentially hazardous solid waste.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/003,150, filed on Jan. 7, 2011, which is a 35 U.S.C. §371 national stage application of PCT/US2009/052709 filed Aug. 4, 2009, which claims the benefit of U.S. Provisional Patent Application No. 61/086,029 filed Aug. 4, 2008, all of which are incorporated herein by reference in their entireties for all purposes.
BACKGROUND
Deepwater accumulators provide a supply of pressurized working fluid for the control and operation of subsea equipment, such as through hydraulic actuators and motors. Typical subsea equipment may include, but is not limited to, blowout preventers (BOPs) that shut off the well bore to secure an oil or gas well from accidental discharges to the environment, gate valves for the control of flow of oil or gas to the surface or to other subsea locations, or hydraulically actuated connectors and similar devices.
Accumulators are typically divided vessels with a gas section and a hydraulic fluid section that operate on a common principle. The principle is to precharge the gas section with pressurized gas to a pressure at or slightly below the anticipated minimum pressure required to operate the subsea equipment. Hydraulic fluid can be added to the accumulator in the separate hydraulic fluid section, increasing the pressure of the pressurized gas and the hydraulic fluid. The hydraulic fluid introduced into the accumulator is therefore stored at a pressure at least as high as the precharge pressure and is available for doing hydraulic work.
Accumulators generally come in three styles—the bladder type having a balloon type bladder to separate the gas from the fluid, the piston type having a piston sliding up and down a seal bore to separate the fluid from the gas, and the float type with a float providing a partial separation of the fluid from the gas and for closing a valve when the float approaches the bottom to prevent the escape of the charging gas. A fourth type of accumulator is pressure compensated for depth and adds the nitrogen precharge pressure plus the ambient seawater pressure to the working fluid.
The precharge gas can be said to act as a spring that is compressed when the gas section is at its lowest volume/greatest pressure and released when the gas section is at its greatest volume/lowest pressure. Accumulators are typically precharged in the absence of hydrostatic pressure and the precharge pressure is limited by the pressure containment and structural design limits of the accumulator vessel under surface ambient conditions. Yet, as accumulators are used in deeper water, the efficiency of conventional accumulators decreases as application of hydrostatic pressure causes the gas to compress, leaving a progressively smaller volume of gas to charge the hydraulic fluid. The gas section must consequently be designed such that the gas still provides enough power to operate the subsea equipment under hydrostatic pressure even as the hydraulic fluid approaches discharge and the gas section is at its greatest volume/lowest pressure.
For example, accumulators at the surface typically provide 3000 psi working fluid maximum pressure. In 1000 feet of seawater the ambient pressure is approximately 465 psi. For an accumulator to provide a 3000 psi differential at 1000 ft. depth, it must actually be precharged to 3000 psi plus 465 psi, or 3465 psi.
At slightly over 4000 ft. water depth, the ambient pressure is almost 2000 psi, so the precharge would be required to be 3000 psi plus 2000 psi, or 5000 psi. This would mean that the precharge would equal the working pressure of the accumulator and any fluid introduced for storage may cause the pressure to exceed the working pressure and accumulator failure.
At progressively greater hydrostatic operating pressures, the accumulator thus has greater pressure containment requirements at non-operational (no ambient hydrostatic pressure) conditions.
The accumulator design must also take into account human error contingencies. For example, removal of the external ambient hydrostatic pressure without evacuating the fluid section of the accumulator to reestablish the original gas section precharge pressure may result in failure due to gas section pressures exceeding the original precharge pressures.
As shown in FIGS. 1 and 2 , accumulators may be included, for example, as part of a subsea BOP stack assembly 10 assembled onto a wellhead assembly 11 on the sea floor 12 . The BOP stack assembly 10 is connected in line between the wellhead assembly 11 and a floating rig 14 through a subsea riser 16 . The BOP stack assembly 10 provides emergency fluid pressure control of fluid in the wellbore 13 should a sudden pressure surge escape the wellbore 13 . The BOP stack assembly thus prevents damage to the floating rig 14 and the subsea riser 16 from fluid pressure exceeding design capacities.
The BOP stack assembly 10 includes a BOP lower riser package 18 that connects the riser 16 to a BOP package 20 . The BOP package 20 includes a frame 22 , BOPs 23 , and accumulators 24 that may be used to provide back up hydraulic fluid pressure for actuating the BOPs 23 . The accumulators 24 are incorporated into the BOP package 20 to maximize the available space and leave maintenance routes clear for working on the components of the subsea BOP package 20 . However, the space available for other BOP package components such as remote operated vehicle (ROV) panels and mounted controls equipment has become harder to establish due to the increasing number and size of the accumulators 24 required to be considered for operation in deeper water depths. Depending on the depth of the wellhead assembly 11 and the design of the BOPs 23 , numerous accumulators 24 must be included on the frame 22 , taking up valuable space on the frame 22 and adding weight to the subsea BOP stack assembly 10 . The accumulators 24 are also typically installed in series where the failure of any one accumulator 24 prevents the additional accumulators 24 from functioning.
The inefficiency of precharging accumulators under non-operational conditions requires large aggregate accumulator volumes that increase the size and weight of the subsea equipment. Yet, offshore rigs are moving further and further offshore to drill in deeper and deeper water. Because of the ever increasing envelop of operation, traditional accumulators have become unmanageable with regards to quantity and location. In some instances, it has even been suggested that in order to accommodate the increasing demands of the conventional accumulator system, a separate subsea skid may have to be run in conjunction with the subsea BOP stack in order to provide the required volume necessary at the limits of the water depth capability of the subsea BOP stack. With rig operators increasingly putting a premium on minimizing size and weight of the drilling equipment to reduce drilling costs, the size and weight of all drilling equipment must be optimized.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more detailed description of the embodiments, reference will now be made to the following accompanying drawings:
FIG. 1 is a schematic of a subsea BOP stack assembly connecting a wellhead assembly to a floating rig through a subsea riser;
FIG. 2 is a perspective view of a BOP package of the BOP stack assembly of FIG. 1 ;
FIG. 3 a cross-section view of an accumulator in accordance with one embodiment of the claimed subject matter; and
FIG. 4 is a cross-section view of an accumulator in accordance with one embodiment of the claimed subject matter.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the drawings and description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. Any use of any form of the terms “connect”, “engage”, “couple”, “attach”, or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.
In FIG. 3 , an accumulator 300 includes an accumulator body 301 with a hydraulic fluid portion 304 and a charge fluid portion 309 . The hydraulic fluid portion 304 partially forms a hydraulic fluid chamber 305 and the charge fluid portion 309 partially forms a precharge gas chamber 310 . An end cap 330 having a hydraulic fluid port 335 seals off an end of the hydraulic fluid portion 304 at one end of the accumulator 300 . Another end cap 340 having a hydrostatic pressure port 345 seals off an end of the charge fluid portion 309 at the other end of the accumulator 300 .
A hydraulic piston 315 is slidably and sealingly mounted in the hydraulic fluid portion 304 . The hydraulic fluid chamber 305 is defined in the hydraulic fluid portion 304 between the hydraulic piston 315 and the end cap 330 . A charge piston 320 is slidably and sealingly mounted in the charge fluid portion 309 . The precharge gas chamber 310 is defined in the charge fluid portion 309 between the charge piston 320 and the hydraulic piston 315 .
At the surface before installation on the sea floor, a precharge gas, such as nitrogen, is provided into the precharge gas chamber 310 and pressurized according to a predetermined depth at which the accumulator will operate and the pressure needed to operate the subsea equipment, such as the rams of the BOPs. A precharge pressure port (not shown) may be, for example, in the side of the accumulator body 301 or in the charge piston 320 . During pressurization of the precharge gas chamber 310 , the hydraulic piston 315 moves towards the end cap 330 . After placement on the seafloor, hydraulic fluid is pumped into the hydraulic fluid chamber 305 , which moves the hydraulic piston 315 towards the opposing end of the hydraulic fluid portion 304 until contacting a shoulder 316 . The hydraulic fluid may be any suitable hydraulic fluid and may also include performance enhancing additives such as a lubricant. The accumulator 300 is then ready to provide pressurized hydraulic fluid to operate the rams of the BOPs.
In normal operation, the force of the precharge gas acting against the hydraulic piston 315 is sufficient to operate the subsea equipment with the hydraulic fluid stored in the hydraulic fluid chamber 305 . However, in case additional force is needed, the accumulator 300 further includes a valve 350 , which communicates ambient hydrostatic pressure through the port 345 when open. That hydrostatic pressure acts against the charge piston 320 and increases the pressure within the precharge gas chamber 310 . The increased pressure of the precharge gas in turn acts against the hydraulic piston 315 to increase the pressure of the hydraulic fluid. As hydraulic fluid is forced out of the hydraulic fluid chamber 305 by movement of the hydraulic piston 315 , the charge piston 320 will move in the same direction with hydrostatic pressure continuing to act against the charge piston 320 . Because hydrostatic pressure acts against the charge piston 320 , the effective increase in pressure of the hydraulic fluid is increased proportional to the difference in piston diameters, giving a multiplier effect to the hydrostatic pressure upon the hydraulic piston 315 . The hydrostatic pressure provides a boost in the force acting on the subsea equipments, such as hydraulic rams of a blowout preventer, which may be useful in an emergency situation. As the hydraulic rams close and the hydraulic fluid exits the accumulator 300 , seawater will flow into the accumulator to apply the constant hydrostatic pressure. Thus, the force applied by the hydraulic rams remains constant between the fully opened and fully closed positions.
Referring now to FIG. 4 , another accumulator 400 is shown that shares many of the same components as the accumulator 300 shown in FIG. 3 . In the accumulator of FIG. 4 however the hydraulic piston 315 is extended to form a piston body 401 that includes a hydraulic diameter portion 402 and a charge diameter portion 403 . The hydraulic diameter portion 402 slidably and sealingly engages the inside of the hydraulic fluid portion 304 of the accumulator body 301 , and the charge diameter portion 403 slidably and sealingly engages the inside of the charge fluid portion 309 of the accumulator body 301 . Although shown as a solid piston body, those having ordinary skill in the art will appreciate that the piston body 401 may be a single hollow piece or any assembly of cylinders that results in a mechanical connection between the hydraulic diameter portion 402 and the charge diameter portion 403 .
The hydraulic fluid chamber 305 is partially defined by the hydraulic fluid portion 402 of the piston body 401 and the end cap 330 . A buffer chamber 405 is defined as the annular space between the outer diameter of the piston body 401 and the inner diameter of the charge fluid portion 309 of the accumulator body 301 . At the surface before installation on the sea floor, the precharge gas is provided into the precharge gas chamber 310 defined between the charge piston 320 and the charge diameter portion 403 of the piston body 401 and pressurized according to a predetermined operating depth and pressure. As shown, the charge diameter portion 403 of the piston body 401 is larger than the hydraulic diameter portion 402 . Thus, the necessary precharge pressure may be reduced proportional to the difference in effective piston area of the two portions of the piston body 401 .
The pressure in the precharge gas chamber 310 at the surface causes the piston body 401 to move towards end cap 330 , which reduces the size of the buffer chamber 405 . Fluid, such as air, contained in the buffer chamber 405 may be vented through port 410 . If port 410 is closed after the piston body 401 has traveled fully towards the end cap 330 , the buffer chamber 405 will have a vacuum when the hydraulic fluid chamber 305 is filled with hydraulic fluid at the sea floor. By having a vacuum, none of the pressure in the precharge gas chamber 310 is counterbalanced by the buffer chamber 405 . If air in the buffer chamber 405 is not vented, actuation of the piston body 401 will compress the air in the buffer chamber 405 , thereby providing a pressure counterbalance to the precharge gas pressure.
In normal operation, the force of the precharge gas acting against the hydraulic piston 315 is sufficient to operate the subsea equipment with the hydraulic fluid stored in the hydraulic fluid chamber 305 . However, in case additional force is needed, the accumulator 300 further includes a valve 350 , which communicates ambient hydrostatic pressure through the port 345 when open. That hydrostatic pressure acts against the charge piston 320 and increases the pressure within the precharge gas chamber 310 . The increased pressure of the precharge gas in turn acts against the charge diameter portion 403 of the piston body 401 to increase the pressure of the hydraulic fluid. As hydraulic fluid is forced out of the hydraulic fluid chamber 305 by movement of the hydraulic diameter portion 402 of the piston body 401 , the piston body 401 will move in the same direction with hydrostatic pressure continuing to act against the charge diameter portion 403 of the piston body 401 . Because hydrostatic pressure acts against charge diameter portion of the piston body 401 via the charge piston 320 , the effective increase in pressure of the hydraulic fluid is increased proportional to the difference in piston diameters, giving a multiplier effect to the hydrostatic pressure upon the hydraulic diameter portion 402 of the piston body 401 . The hydrostatic pressure provides a boost in the force acting on the subsea equipment, such as hydraulic rams of a blowout preventer, which may be useful in an emergency situation. As the hydraulic rams close and the hydraulic fluid exits the accumulator 300 , seawater will flow into the accumulator to apply the constant hydrostatic pressure. Thus, the force applied by the hydraulic rams remains constant between the fully opened and fully closed positions.
While specific embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments as described are exemplary only and are not limiting. Many variations and modifications are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.
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An accumulator for hydraulically actuating subsea equipment includes a hydraulic fluid chamber and a gas chamber. The hydraulic fluid chamber is in fluid communication with the subsea equipment and comprises a hydraulic piston slidably received, at least partially, within the hydraulic chamber. The gas chamber comprises a charge piston slidably received within the gas chamber, the charge piston dividing the gas chamber into a first portion and a second portion. The first portion of the gas chamber is configured to receive ambient hydrostatic pressure therein, and the second portion of the gas chamber is configured to receive precharge gas therein.
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BACKGROUND OF THE INVENTION
(a) Field of the Invention:
The present invention relates to a controller used with an automotive rearview mirror using electrochromism to automatically adjust the light reflectivity of the inside rearview mirror surface stepwisely accordingly to the brightness in the surroundings of the car or automobile. b) Related Art Statement:
Heretofore, automotive rearview mirrors have already been proposed of which the mirror surface is made of an electrochromic element and colored by changing the voltage applied to the electrochromic element according to the brightness of the surroundings of the automobile, thereby adjusting the light reflectivity of the mirror surface (the rearview mirror of this type will be referred to as "EC mirror" hereinafter). For example, the Applicant's copending Japanese Utility Model Application No. 60-199295 (filed on Dec. 26, 1985) discloses a controller adapted for use with such EC mirror to reduce, when the photosensor disposed at a part of the mirror housing of the EC mirror of a car is exposed to a strong light from the headlights of a car behind the light reflectivity of the EC mirror so that the driver of the car will not be dazzled by the brightness of the light from the headlights of the car behind. As known from the disclosure in the U.S. Pat. No. 4293194, the electrochromic element is of a multilayer structure in which each of two thin chromic layers is placed between transparent electrodes. The first chromic layer is made of, for example, Ni(OH) 2 which becomes blue when oxidized, while the second chromic layer is made of, for example, tungsten oxide WO 3 which is colored when deoxidized due to the oxidation of the first chromic layer.
The EC mirror using the above-mentioned electrochromic element has normally a high reflectivity but this reflectivity is automatically changed to a predetermined low reflectivity when the mirror is exposed to a strong light beam from the headlights of a car behind. However, the dazzle felt by the driver's eyes varies depending upon the intensity of the light from the headlights of the car behind. On the other hand, the low reflectivity of the EC mirror is predetermined, namely, fixed at a certain level, so that it cannot be variously changed according to the extent of dazzle felt by the driver's eyes. Also there is a problem that it is difficult to set an optimum low reflectivity at which the driver will not be dazzled.
SUMMARY OF THE INVENTION
Therefore, the present invention has an object to provide a controller used with an EC mirror to automatically change the light reflectivity of the mirror surface stepwisely according to the intensity of the light beam from the headlights of a car behind.
It is another object of the present invention to provide an EC-mirror light reflectivity controller which is capable of controlling automatically and stepwisely the light reflectivity of the mirror surface according to the intensity of the light beam from the headlights of a car behind only when the brightness of the surroundings of a car including the brightness at the front thereof has become lower than a predetermined value.
It is still another object of the present invention to provide an EC mirror light reflectivity controller which is adapted so as to control automatically and stepwisely the light reflectivity of the mirror surface according to the intensity of the light beam from the headlights of a car behind only when the brightness of the surroundings of a car including the brightness at the front thereof has become lower than a predetermined value and to decolorize, when changing the reflectivity of the EC mirror from a low in a certain colored state to high in a more lightly colored state, the EC mirror once for a preset time and thereafter change the reflectivity to a higher reflectivity in the more lightly colored state.
These and other objects and advantages of the present invention will be better understood from the ensuing description made, by way of example, of the embodiments of the present invention with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing a first embodiment of the light reflectivity controller according to the present invention;
FIG. 2 graphically shows an output of the two photosensors shown in FIG. 1, which varies correspondingly to the brightness of the surroundings;
FIG. 3 is a schematic sectional view of the electrochromic element shown in FIG. 1;
FIG. 4 is a circuit diagram of a second embodiment of the light reflectivity controller according to the present invention; and
FIG. 5 graphically shows an output of the two photosensors shown in FIG. 4, which varies correspondingly to the brightness of the surroundings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the light reflectivity controller for EC mirror according to the present invention will be described below with reference to FIGS. 1 to 3.
Referring now to FIG. 1, the reference numeral 10 indicates a photodetector which detects the brightness of the surroundings of a car in which the EC mirror is equipped. This photodetector 10 is comprised of two photosensors 12 and 14, one being disposed on the rear side of the EC mirror while the other is disposed on the front side thereof. Each of these photosensors 12 and 14 comprises a detecting element and preamplifier. The photosensor 12 is so adapted as to detect the brightness X of the surroundings including the front of the car, while the photosensor 14 is to detect the brightness Y of the surroundings including the rear of the car. These photosensors 12 and 14 produce output signals, respectively, inversely proportional to the brightness X and Y, respectively, of the surroundings. The output signals from the photosensors 12 and 14, respectively, are sent t a comparison circuit 16. The comparison circuit 16 comprises two comparators 18 and 22 which receive output signal from the photosensor 12, and a comparator 26 which receives output signal from the photosensor 14. For the comparators 18, 22 and 26, respectively, disposed are reference voltage generation circuits 20, 24 and 28 which deliver a reference voltages ref1, ref2 and ref3, respectively. The signals ref1, ref2 and ref3 correspond to the brightness A, B and C (A > B > C), respectively, of the surroundings of the car as shown in FIG. 2. The reference voltages ref1, ref2 and ref3 are set as ref1 < ref2 < ref3. In this case, the brightness higher than A nearly corresponds to the sufficiently bright daylight, the brightness between A and B corresponds nearly to the twilight in which the surroundings are lightly dark, the brightness between B and C nearly corresponds to a brightness in the night but when the EC mirror is influenced by the light beam from the headlights from a car behind, and the brightness lower than C corresponds nearly to the brightness in the dark night.
The comparators 18, 22 and 26 are so adapted as to deliver a "L" level signal when the output signal from the photosensor 12 or 14 is higher than the corresponding reference voltages ref1, ref2 and ref3, while delivering an "H" level signal when the output signal from the photosensor is lower than the corresponding reference voltages ref1, ref2 and ref3.
The output terminals of the comparators 18 and 22 are connected to the first and second terminals, respectively, of a NAND gate 32 of which the output terminal is connected to the first terminal of an AND gate 34. The output terminal of the comparator 26 is connected to the second terminal of the AND gate 34 of which the output terminal is connected to the coil of a relay 36. When the coil of this relay 36 is not excited, a transparent electrode 56 at the side of an oxidation-colored thin layer 55 of an electrochromic element 40 shown in FIG. 3 and which will be described later is connected to the ground potential. When the coil of the relay 36 is excited, the contact 38 of the relay connects the transparent electrode 56 at the side of the oxidation-colored thin layer 55 to a voltage regulation circuit 42 which will be described later. The NAND gate 32, AND gate 34 and relay 36 form together a switching control circuit 30 which connects the transparent electrode 56 at the side of the oxidized chromic thin layer 55 to either the ground potential or the voltage regulation circuit 42 selectively based on the signals delivered from the comparators.
The output terminals of the comparators 18 and 22 are connected to the bases of transistors TR1 and TR2, respectively. These transistors TR1 and TR2 are of a PNP junction type. Each emitter is connected to the positive pole of a battery 50 and also to the input terminal of the voltage regulation circuit 42. When the signal level at the bases of these transistors TR1 and TR2 is "L" as compared with that at their emitters, each transistor is turned on as conductive between the emitter and collector thereof. The collector of the transistor TR1 is connected to one end of a resistor R1. Resistors R1, R2 and R3 are connected in series to one another, and the resistor R3 is connected to the ground potential. The transistor TR2 has the collector connected to the common terminal of the resistors R1 and R2. The common terminal of the resistors R2 and R3 is connected to a control input terminal C of the voltage regulation circuit 42. The resistors R1, R2 and R3 form together a voltage divider which forms a voltage control generation circuit 44 together with the voltage regulation circuit 42. When TR1 and TR2 are turned on, the control input terminal C of the voltage regulation circuit 42 is supplied with a voltage of Vc=V.R3/(R2+R3) and TR1 is on while TR2 is off, the control input terminal C of the voltage regulation circuit 42 is applied with a voltage of Vc=V.R3/(R1+R2+R3) (V is the voltage of the battery 50). In case TR1 is off while TR2 is on, the control input terminal C of the voltage regulation circuit 42 is supplied with a voltage of Vc=V.R3/(R2+R3). The battery 50 is so arranged as to provide the control voltage Vc applied to the control input terminal C.
The EC mirror using the electrochromic element 40 in this embodiment is shown in detail in FIG. 3. As seen, the EC mirror is comprised of a chromic lamination including the first transparent electrode 52 and a deoxidation-colored oxidized thin layer 53, electrolytic layer 54, oxidation-colored oxidized thin layer 55 and second transparent electrode 56 laminated on the first transparent electrode sequentially in this order, a transparent glass 57 outside the first transparent electrode 52 and also a transparent glass 57 outside the second transparent electrode 56 with an layer 53 is made of W03 or Mo02, the electrolytic layer 54 is of a solid Ta 2 O 3 or ZrO 2 , and the oxidation-colored oxidized thin layer 55 is of CrO 2 , Ni(OH) 2 or Rh(OH) 2 . Assume now that the first transparent electrode 52 is placed at a negative potential while the second transparent electrode 56 is at a positive potential. The deoxidation-colored oxidized thin layer 53 is deoxidized and colored and at the same time the oxidation-colored oxidized thin layer 5 is oxidized and colored, so that the glass layer 51 has a low reflectivity as colored correspondingly to the potential. On the contrary, when the first transparent electrode 2 is let to have a positive potential while the second transparent electrode 56 is placed at a negative potential, the deoxidation-colored oxidized thin layer 53 is oxidized and becomes transparent and at the same time the oxidation-colored oxidized thin layer 55 is deoxidized and becomes also transparent, so that the glass layer 57 with the aluminum evaporated layer 58 at the back thereof will have a high reflectivity.
The EC mirror using such electrochromic element 40 is operated by the light reflectivity controller shown in FIG. 1 as will be described below:
(a) When the brightness X of the surroundings including the front of the car is higher than A, namely, when the brightness is nearly equivalent to the daylight brightness, the output from the photosensor 12 is lower than the reference voltage ref1. Therefore, the inputs to the comparators 18 and 22 are lower than the reference voltages ref1 and ref2, respectively, so that the outputs from the comparators 18 and 22 will have "H" level. The output signals from the comparators 18 and 22 are supplied to the first and second input terminals of the NAND gate 32. Since both these inputs have "H" level, the output signal from the NAND gate 32 has "L" level. This signal is supplied to the AND gate 34. When one of the inputs to the AND gate 34 is at "L" level, the output from this AND gate 34 will take "L" level irrespectively of any input to the AND gate 34, so that the coil of the relay 36 will not be excited and the relay contact 38 be kept connected to the ground potential as shown in FIG. 2. On the other hand, the output signal from each of the comparators 18 and 22 are also supplied to the transistors TR1 and TR2 of which the bases in turn will take "H" level. These transistors are turned on as conductive between the emitter and collector thereof. At this time, the control input terminal C of the voltage regulation circuit 42 is applied with a voltage of V.R3/(R2+R3). However, the relay contact 38 is kept connected to the ground potential. Namely, since both the electrode 56 at the side of the oxidation-colored oxidized thin layer 55 and the electrode 52 at the side of deoxidation-colored oxidized thin layer 53, of the electrochromic element 50, are short-circuited as connected to the ground potential, the glass layer 57 takes a high reflectivity. As described in the foregoing, when the brightness X of the surroundings including the front of the car is higher than A as shown in FIG. 2, the EC mirror will have a high reflectivity independently of the brightness Y of the surroundings including the rear of the car.
(b) Next, when the brightness Y of the surroundings including the rear of the car is lower than C as shown in FIG. 2, that is, when the brightness is nearly equivalent to the brightness in the night and it is not influenced by the light beam from the headlights of a car behind, the output from the photosensor 14 is higher than the reference voltage ref3 so that the output signal from the comparator 26 will take "L" level. The "L" level output signal from the comparator 26 is supplied to the second input terminal of the AND gate 34, but the output from the AND gate 34 takes "L" level irrespectively of the input signal from the NAND gate 32. Hence, the coil of the relay 36 is not excited and the relay contact 38 is connected to the ground potential as shown in FIG. 1. The light reflectivity of the EC mirror will be high as in the aforementioned case (a).
(c) When the brightness X of the surroundings including the front of the car is lower than A and higher than B shown in FIG. 2 and the brightness Y of the surroundings including the rear of the car is higher than C shown in FIG. 2, namely, when the brightness is nearly equivalent to that in the twilight and the light beam from the headlights of a car behind is incident upon the EC mirror, the output from the photosensor 12 is higher than the reference voltage ref1 and lower than ref2, so that the output signal from the comparator 18 will take "L" level while the output signal from the comparator 22 take "H" level. Since the output from the photosensor 14 is lower than the reference voltage ref3, the output signal from the comparator 26 will take "H" level. Therefore, the two input terminals of the NAND gate 32 are supplied with "L" and "H" level signals, respectively, from the comparators 18 and 22, respectively, so that the relay contact 38 is switched from the ground potential side to the output terminal of the voltage regulation circuit 42. On the other hand, the "L" and "H" level signals from the comparators 18 and 22, respectively, are supplied to the bases of the transistors TR1 and TR2, respectively, with the result that the transistor TR1 is turned on while the transistor TR2 is turned off. Hence, the control input terminal C of the voltage regulation circuit 42 is applied with a voltage of V.R3/(RI+R2+R3) which is delivered at the output terminal of the voltage regulation circuit 42. Since the relay contact 38 has been switched from the ground potential side to the output terminal of the voltage regulation circuit 42, the electrode 56 at the side of the oxidation-colored oxidized thin layer 55 of the electrochromic element 40 is applied with a voltage of V.R3/(R1+R2+R3). The electrodes 56 and 52 are colored depending upon this voltage. In this condition, the EC mirror will has the first low reflectivity.
(d) Next, when the brightness X of the surroundings including the front of the car is lower than B shown in FIG. 2 and the brightness Y of the surroundings including the rear of the car is higher than C and lower than B shown in FIG. 2, that is, when the surroundings of the car is very dark and the light beam from the headlights from a car behind is incident upon the EC mirror, the output from the photosensor 12 is higher than the reference voltage ref2 while the output from the photosensor 14 is lower then ref3 and higher than ref2. Therefore, both the output signals from the comparators 18 and 22 take "L" level while the output signal from the comparator 26 takes "H" level. The "L" level output signals from the comparators 18 and 22 are supplied to the bases of the transistors TR1 and TR2, respectively, which in turn will be turned on. As a result, the voltage regulation circuit 42 is applied at the control input terminal C thereof with a voltage V.R3/(R2+R3) which will be delivered from the voltage regulation circuit 42. On the other hand, both the "L" level output signals from the comparators 18 and 22 are supplied to the NAND gate 32 of which the output in turn will take "H" level. Both the "H" level output signal from the NAND gate 32 and the "H" level output signal from the comparator 26 are supplied to the AND gate 24 o which the output signal will take "H" level. Consequently, the coil of the relay 36 is excited so that the relay contact 38 will be switched to the output terminal of the voltage regulation circuit 42. As a result, the electrode 56 at the side of oxidation-colored oxidized thin layer 55 of the electrochromic element 40 is applied with a voltage of V R3/(R2+R3). The electrodes 56 and 52 are colored depending upon the voltage of V.R3/(R2+R3). The electrochromic element 40 has such a property that the higher the voltage applied between the electrodes, the more darkly the element is colored. Since the applied voltage of V.R3/(R2+R3) as in (c) above is higher than V.R3/(R1+R2+R3), the electrochromic element will be more darkly colored as compared with the coloring in (c). In this condition, the EC mirror has a second low reflectivity which is lower than the first low reflectivity.
As having been described in the foregoing, according to this embodiment, when the brightness X of the surroundings including the front of the car is sufficiently high and the brightness Y of the surroundings including the rear of the car is sufficiently low, the EC mirror will represent a high reflectivity; when the brightness X of the surroundings including the front of the car is nearly equivalent to that in the twilight in which the brightness is slightly low and also when the light beam from the headlights of a car behind is incident upon the EC mirror, the EC mirror will take a first low reflectivity which is somewhat lower; and when the brightness X of the surroundings including the front of the car is sufficiently low and the light beam from the headlights of a car behind is incident upon the EC mirror, the EC mirror will represent a second low reflectivity that is further lower than the first low reflectivity. Since the reflectivity is thus automatically changed over depending upon the brightness of the surroundings, the EC mirror can always keep providing a well-visible rear view without any dazzling of the driver by the light from the headlights of a car behind him.
FIG. 4 shows a second embodiment of the light reflectivity controller for EC mirror according to the present invention. In FIG. 4, the reference numeral 60 indicates a photodetector which detects the brightness of the surroundings of a car in which the EC mirror is equipped. This photodetector 60 is comprised of two photosensors 62 and 64, one being disposed on the rear side of the EC mirror while the other is disposed on the front side thereof. Each of these photosensors 62 and 64 comprises a detecting element and preamplifier. The photosensor 62 is adapted so as to detect the brightness X of the surroundings including the front of the car, while the photosensor 64 is to detect the brightness Y of the surroundings including the rear of the car. These photosensors 62 and 64 produce output signals, respectively, inversely proportional to the brightness X and Y, respectively, of the surroundings. The output signals from the photosensors 62 and 64, respectively, are sent to a comparison circuit 66. The comparison circuit 66 comprises a comparator 68 which receives an output signal from the photosensor 62, and three comparators 72, 76 and 80 which receives output signal from the photosensor 64. For the comparators 68, 72, 76 and 78, respectively, disposed are reference voltage generation circuits 70, 74, 78 and 82 which deliver reference voltages ref4, ref5, ref6 and ref7, respectively. The signals ref4, ref5, ref6 and ref7 generally correspond to the brightness D, E, F and G (D<E<F<G), respectively, of the surroundings of the car. The reference voltages ref4, ref5, ref6 and ref7 are set as ref4>ref5>ref6>ref7.
When the signal from the photosensor 62 is higher than the reference voltage ref4, the comparator 68 delivers "H" level signal. In case the signal is lower than ref4, the comparator 68 provides "L" level signal. When the signal from the photosensor 64 is higher than the reference voltages ref5, ref6 and ref7, respectively, the comparators 72, 76 and 80 deliver "L" level signals. They will provide "H" level signals when the signal from the photosensor 64 is lower than ref5, ref6 and ref7, respectively.
The output terminal of the comparator 68 is connected to the first input terminal of an AND gate 92, while the output terminals of the comparators 72, 76 and 80 are connected to the first input terminals of an AND gate 86, AND gate 88 and OR gate 90, respectively. The output terminals of the comparators 72 and 76 are connected to the third and second input terminals, respectively, of the OR gate 90. The second input terminal of an AND gate 92 is connected to the output terminal of the AND gate 86 through a capacitor C1, and to the positive pole of a power source 104 through a resistor R4. The third input terminal of the AND gate 92 is connected to the output terminal of the AND gate 88 through a capacitor C2, and to the positive pole of the battery (power source) 104 through a resistor R5. The fourth input terminal of the AND gate 92 is connected to the output terminal of the OR gate 90. Also the first input terminal of the AND gate 86 and the third input terminal of the OR gate 90 are connected to the base of a transistor TR3, the second input terminal of the AND gate 86, the first input terminal of the AND gate 88 and the second input terminal of the OR gate 90 are connected to the base of a transistor TR4, and the second input terminal of the AND gate 88 and the first input terminal of the OR gate 90 are connected to the base of a transistor TR5. The transistors TR3 to TR5 are of NPN junction type. They are turned on as conductive between the emitter and collector thereof when the base has "H" level with respect to the emitter. Each collector is connected to the positive pole of the battery 104 and also to the input terminal of a voltage regulation circuit 100. Between the emitter of the transistor TR3 and the ground potential are connected to resistors R6, R7, R8 and R9 in series with one another. These resistors are disposed as follows. Namely, the resistor R6 is connected between the emitters of TR3 and TR4, respectively; R7 is between the emitters of TR4 and TR5, respectively; R8 is between the emitter of TR5 and the control input terminal of the voltage regulation circuit 100; and R9 is between the control input terminal C of the voltage regulation circuit 100 and the ground potential. These resistors R6 to R9 form together a voltage divider which form together with the voltage regulation circuit 100 a control voltage generation circuit 102 which changes a voltage Vc applied to the control input terminal C and makes the voltage the output of the voltage regulation circuit 100. Namely, this voltage Vc varies as any of the transistors TR3 to TR5 turns on in correspondence to the brightness of the surroundings of the car that is detected by the photosensors 62 and 64, and it is applied to an electrochromic element 98.
The AND gate 92 is so adapted that when all the signals supplied to the input terminals have "H" level, it will deliver "H" level signal to excite the coil of a relay 94, thereby switching a relay contact 96 for the voltage Vc to be applied to the electrochromic element 98. The AND gate 86, AND gate 88, OR gate 90, AND gate 92 and relay 94 form together a switching control circuit 84 which switches the electrode 0 at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 to either the output terminal of the voltage regulation circuit 100 or the ground potential correspondingly to the brightness of the surroundings of the car that is detected by the photosensors 62 and 64.
The AND gate 86, capacitor C1, resistor R4 and battery 104 form together a fist time-constant circuit, while the AND gate 88, capacitor C2, resistor R5 and battery 100 form together a second time-constant circuit.
The construction of the electrochromic element 98 is similar to that of the electrochromic element 40 adopted in the first embodiment shown in FIG. 3. The electrode 0 at the oxidation-colored oxidized thin layer is selectively connected to either the output terminal of the voltage regulation circuit 100 or the ground potential through the relay contact 96, while the electrode R at the side of the deoxidation-colored oxidized thin layer is connected to the ground potential. That is, the relay contact 96 is normally connected to the ground potential, and so the electrochromic element 98 is kept short-circuited. When the coil of the relay 94 is excited, the electrochromic element 98 is connected to the output terminal of the voltage regulation circuit 100 and is applied with a certain voltage corresponding to the brightness of the surroundings of the car.
The light reflectivity controller for EC mirror according to the second embodiment of the present invention functions as follows:
(a) When the brightness X of the surroundings including the front of the car is higher than D, the output from the photosensor 62, namely, the input to the comparator 68, is lower than the reference voltage ref4 and thus the output signal takes "L" level. Therefore, the 4-input AND gate 92 is supplied at the first input terminal thereof with "L" level signal, with the result that the output signal from the AND gate 92 takes "L" level irrespectively of the signal detected by the photosensor 64 so that the coil of the relay 94 will not be excited. Thus, the relay contact 96 is connected to the ground potential and the electrochromic element 98 is kept short-circuited. This means that the EC mirror has a high reflectivity.
(b) When the brightness X of the surroundings including the front of the car is lower than D, the output from the photosensor 64, namely, the input to the comparator 8, is higher than the reference voltage ref4, and so the output signal takes "H" level. Therefore, the 4-input AND gate 92 is supplied at the first input terminal thereof with "H" level signal. The output signal from the AND gate 92 takes "H" level when all the output signals from the AND gate 86, AND gate 88 and OR gate 90 are at "H" level, while the output signal of the AND gate 92 takes "L" level when any of the output signals from the AND gate 96, AND gate 88 and OR gate 90 is at "L".
It will be apparent from the above, the EC mirror reflectivity control is so made that the brightness X of the surroundings including the front of the car is higher than D, the EC mirror keeps a high reflectivity independently of the brightness of the surroundings including the rear of the car, while the reflectivity of the EC mirror is made low in correspondence to the brightness Y of the surroundings including the rear of the car when the brightness X is lower than D.
(c) When the brightness X of the surroundings including the front of the car is lower than D and the brightness Y of the surroundings including the rear of the car is lower than E, the output signal from the photosensor 64 is higher than all the reference voltages ref5, ref6 and ref7, so that the output signals from the comparators 72, 76 and 80 will represent "L" level. Since these output signals are supplied to the OR gate 90, the output signal from the OR gate 90 will take "L" level. Since this "L" level signal is also supplied to the fourth input terminal of the AND gate 92, the output signal from this AND gate 92 will also take the "L" level. Thus, since the coil of the relay 94 is not excited, the electrochromic element 98 is kept short-circuited so that the EC mirror will have a high reflectivity.
(d) Next, when the brightness X of the surroundings including the front of the car is lower than D and the brightness Y of the surroundings including the rear of the car is above E and less than F, that is, when the brightness Y of the surroundings including the rear of the car is slightly increased up to E≦Y<F, the input signals to the comparators 72, 76 and 88 are lower than ref5 but higher than ref6 and ref7. Therefore, the output signal of the comparator 72 will take "H" level while the output signals from the comparators 76 and 80 will have "L" Level. Since the "H" level output signal from the comparator 72 is supplied to the base of the transistor TR3 while the "L" level output signals from the comparators 76 and 80 are supplied to the bases of the transistors TR4 and TR5, respectively, TR3 is turned on while the TR4 and TR5 are turned off. The "H" level output signal from the comparator 72 is further supplied to the first input terminal of the AND gate 86 and the third input terminal of the OR gate 90, the "L" level output signal from the comparator 76 is also supplied to the first input terminal of the AND gate 88 and the second input terminal of the OR gate 90, and the "L" level output signal from the comparator 80 is further supplied to the second input terminal of the AND gate 88 and the first input terminal of the OR gate 90, so that both the output signals from the AND gates 86 and 88 will take "L" level. As a result, the voltage regulation circuit 100 is applied at the control input terminal C thereof with a voltage of V.R9/(R6+R7+R8+R9) which will be the output voltage from the voltage regulation circuit 100. Also the output signal from the OR gate 90 takes "H" level and has been supplied to the fourth input terminal of the AND gate 92. Both the output signals from the AND gates 86 and 88 take "L" level. However, since C1 and C2 will be completely charged when a time determined by a first time-constant circuit including C1 and R1 and a second time-constant circuit including C2 and R5, that is, a time from the connection of R4 and R5 to the battery 104 until T1=C1.R4 and T2=C2.R5, passes, the potentials at the second and third input terminals of the AND gate 92 take "H" level, and at the same time the output signal from the AND gate 92 also takes "H" level. Thus, the coil of the relay 94 is excited and the relay contact 96 is connected to the output terminal of the voltage regulation circuit 100, so that the electrode 0 at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 is applied with the aforementioned voltage of V.R9/(R6+R7+R8+R9) so that the EC mirror will be colored and represent a first low reflectivity.
(e) In case the brightness Y of the surroundings including the rear of the car is further increased up to F≦Y<G, the input signals to the comparators 72, 76 and 80 are higher than the reference voltages ref5 and ref6 but higher than ref7 so that the output signals from the comparators 72, 76 and 80 will have "H", "H" and "L" levels, respectively. Thus, the output signals from the AND gate 86 and OR gate 90 take "H" level, respectively, while the output signal from the AND gate 88 maintains "H" level. Therefore, the signals supplied to the second and fourth input terminals of the AND gate 92 represent "H" level, while the signal supplied to the third input terminal keeps "H" level as mentioned above. Since the potential in the capacitor C1 at the side of R4 is at "H" level although the output signal from the AND gate 86 has changed from "L" to "H" level, the signal supplied to the second input terminal of the AND gate 92 remains at "H" level. However, at this time, the capacitor C1 has been discharged in a circuit comprising the battery 104, resistor R4, capacitor C1 and AND gate 86. Hence, since all the four input signals to the AND gate 92 are held at "H" level, the output signal will also take "H" level so that the coil of the relay 94 will be kept excited and the relay contact 96 will remain connected to the voltage regulation circuit 100. On the other hand, since the transistors TR3 and TR4 are turned on, the voltage regulation circuit is applied at the control input terminal thereof with a voltage of V.R9/(R7+R8+R9) which will be applied to the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98. This voltage is higher than the voltage of V.R9/(R6+R7+R8+R9) in the preceding case. In case the brightness Y of the surroundings including the rear of the car is increased, the voltage applied to the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 becomes higher so that the EC mirror will has a decreased reflectivity. It will be apparent that the light reflectivity of the EC mirror becomes the second low reflectivity that is further lower than the aforementioned first low reflectivity.
(f) In case the brightness Y of the surroundings including the rear of the car increases up to Y≧G, the relay contact 96 is kept connected to the output terminal of the
voltage regulation circuit 100 as in the case of F≦Y<G. On the other hand, since all the output signals from the comparators 72, 76 and 80 take "H" level, all the transistors TR3 to TR5 are turned on so that the voltage regulation circuit 100 is applied at the control input terminal C thereof with a voltage of V.R9/(R8+R9) which will be applied to the electrode 0 at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98. Since this voltage is higher than the voltage of V.R9/(R7+R8+R9) being the voltage applied in case of F≦Y<G, the EC mirror is more darkly colored so that the light reflectivity thereof will further fall down to a third low reflectivity that is further lower than the aforementioned first and second low reflectivities.
(g) Next, if the brightness Y of the surroundings including the rear of the car decreases from Y≧G to F≦Y<G, the input signals to the comparators 72, 76 and 80 are lower than ref5 and ref6 while being higher than ref7, so that the output signals from the comparators 72 and 76 keep "H" level while the output signal from the comparator 80 is changed from "H" to "L" level. Consequently, the transistors TR3 and TR4 remain turned on while the transistor TR5 is turned off, so that the voltage applied to the control input terminal of the voltage regulation circuit 100 is switched from V.R9/(R8+R9) to V.R9/(R7+R8+R9). On the other hand, since the output signals from the AND gate 86 and OR gate 90 keep "H" level, "H" level signal is transmitted to the second and fourth input terminals of the AND gate 92. However, the AND gate 88 is supplied at the first input terminal thereof with "H" level signal as it is from the comparator 80 but since "L" level signal from the comparator 80 is supplied to the second input terminal, the output signal from the AND gate 88 will take "L" level. In case the output signal from the AND gate 88 takes "L" level, the signal level at the terminal of the capacitor C2 at the side of the AND gate 88 takes "L" level (ground potential) so that the terminal of the capacitor C2 in a discharged condition at the side of resistor R5 also takes "L" level. Thus, the AND gate 92 will be supplied at the third input terminal thereof with "L" level signal. Consequently, the output signal from the AND gate 92 also takes "L" level so that the coil of the relay 94 is not excited with the result that the relay contact 96 will be switched to the ground potential and the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 will take the ground potential level as with the electrode R at the deoxidation-colored oxidized thin layer, thereby decolorizing the EC mirror. However, since the capacitor has started being charged through the resistor R5, the charging is completed when a time of T2=C2×R5 has passed and the terminal of the capacitor C2 at the side of the resistor R5 will restore to "H" level. Therefore, all the input signals to the AND gate 92 take "H" level with the result that the coil of the relay 94 will be excited with the "H" level output signal from the AND gate 92, the relay contact 96 be switched to the output terminal of the voltage regulation circuit 100 and the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 be applied with a voltage of V.R9/(R7+R8+R9). Thus it will be apparent that the EC mirror is slightly less colored than in the case of Y≧G and takes the second low reflectivity.
(h) Next, when the brightness Y of the surroundings including the rear of the car is decreased from a range of F≦Y<G to a range of E≦Y<F, the transistors TR3 and TR5 remain turned on and off, respectively, and the transistor TR4 is switched from on to off state. At this time, the signal supplied to the second input terminal of the AND gate 86 has "L" level so that the signal supplied to the second input terminal of the AND gate 86 keeps "L" level for a time of T1=C1.R4 during which the output signal from the AND gate 92 also takes "L" level. Therefore, as the relay contact 96 is switched to the ground potential, the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 takes the ground potential level as with the electrode R at the deoxidation-colored oxidized thin layer, so that the EC mirror is decolorized. Further, when a time T1 passes, the relay contact 96 is switched to the output terminal of the voltage regulation circuit 100 again. So the electrode O at the side of the oxidation-colored oxidized thin layer is applied with a voltage V.R9/(R6+R7+R8+R9). Thus it will be appreciated that the EC mirror is further decolorized down to the first low reflectivity.
(i) hen the brightness Y of the surroundings including the rear of the car is further decreased from a range of E≦Y<F to a range of Y≦E, the output signal from the OR gate 90 takes "L" level so that the output signal from the AND 92 also takes "L" level with the result that the coil of the relay 94 gets non-excited. Thus, the relay contact 96 is switched to the ground potential, the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 takes the ground potential as with the electrode R at the deoxidation-colored oxidized thin layer, and the EC mirror gets the high reflectivity as decolorized.
As having been described in the foregoing, according to this embodiment, the comparator 68 which provides a reference voltage ref4 is provided for the photosensor 62 and three comparators 72, 76 and 80 which produce reference voltages ref5, ref6 and ref7 are disposed for the photosensor 64. It will be evident that the number of the comparators and the reference voltages may be variously set.
Also according to the embodiment, such an arrangement is made that the voltage applied to the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 is changed depending upon the brightness X of the surroundings including the front of the car and brightness Y of the surroundings including the rear of the car. However, in case the brightness X of the surroundings including the front of the car is substantially X≧D, the voltage applied to the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 takes the ground potential level and the EC mirror has the high reflectivity independently of the brightness Y of the surroundings including the rear of the car. So in case the brightness X of the surroundings including the front of the car is within a range of X<D, namely, in case of rather dark surroundings, the light reflectivity can be controlled automatically and stepwisely correspondingly to the brightness Y of the surroundings including the rear of the car, namely, the brightness due to the light beam from the headlights of a car behind. Only when the brightness Y of the surroundings including the rear of the car is higher than E which is higher than D, the EC mirror will be colored. Further, in case the reflectivity of the EC mirror is changed from low to high, for example, when the strong light beam incident upon the EC mirror from the headlights of a car behind suddenly leave the EC mirror, the electrode O at the side of the oxidation-colored oxidized thin layer of the electrochromic element 98 and the electrode R at the side of deoxidation-colored oxidized thin layer are short-circuited between them once for a short time determined by the time-constant circuits, the EC mirror is decolorized and thereafter the mirror's reflectivity is shifted to the high one. So the delay in transition of the electrochromic element 98 can be effectively eliminated so that the light reflectivity of the reflective surface of the mirror can be changed in a very short time correspondingly to the brightness of the surroundings of the car. Thus the EC mirror can be made very easily viewable.
The present invention has been described in the foregoing with respect to the first and second embodiments of the present invention. However, it will be evident to those skilled in the art that the present invention is not limited to these embodiments alone but various many modifications and corrections can be done of the present invention.
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The light reflectivity control for use with an automotive rearview mirror according to the present invention has a first and second photosensors to detect the brightness of the surroundings including the front of a car in which the inside rearview mirror is equipped and that of the surroundings including the rear of the car, respectively. These photosensors deliver output signals in inverse proportion to the respective brightnesses of the surroundings of the car. The output signals are supplied to a first and second comparators each having at least a reference value predetermined correspondingly to the brightness of the surroundings, in which the output signals are compared with the reference values, respectively. Based on the signal including the information concerning the brightness of the surroundings including the front and rear, respectively, of the car and that are delivered from the comparators, voltages for application to the electrochromic elements and then the electrochromic elements are connected. Thereby, the voltage for application to the electrochromic elements are automatically and stepwisely correspondingly to the brightness of the surroundings of the car.
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FIELD OF THE INVENTION
[0001] The present invention relates to a virtual sport system using a start sensor.
BACKGROUND
[0002] Virtual golf systems are widely spreading which allow golfers to virtually play golf at low cost in downtown areas and the like. The basic concept of such virtual golf systems is to measure physical quantities of a golf ball upon being hit by a golfer, perform a simulation of the shot, and display a result of the simulation on a screen. In the virtual golf systems, it is important to accurately measure the physical quantities of the golf ball.
[0003] While there are many types of physical quantities of the golf ball, it may be important to accurately measure the physical quantities of the golf ball at the stage of starting movement, which may greatly affect the result of the simulation. However, conventional techniques have been insufficient for such measurement.
[0004] Following the introduction of a remarkable virtual golf system in Korean Patent No. 1048864 (entitled, “METHOD OF MEASURING PHYSICAL QUANTITIES OF OBJECT BY USING SINGLE LIGHT SOURCE AND PLANAR SENSOR UNIT AND VIRTUAL GOLF SYSTEM UTILIZING SAME”) (the contents of which are incorporated herein by reference in its entirety), the inventor(s) now present a novel feature to combine with such virtual golf systems, other virtual golf systems, systems for virtually playing other kinds of sports (e.g., baseball, football, etc.), or the like to enable them to produce more accurate simulation results.
SUMMARY OF THE INVENTION
[0005] One object of the present invention is to accurately measure physical quantities of a ball at the stage of starting movement.
[0006] Another object of the invention is to enable a virtual sport system to produce a more accurate simulation result.
[0007] According to one aspect of the invention to achieve the objects as described above, there is provided a virtual sport system, comprising: a shot unit to allow a ball to be hit; a start sensor unit to derive information on physical quantities of the ball at the stage of starting movement; and a simulation unit to receive the information on the physical quantities from the start sensor unit and perform a simulation of the movement of the ball on the basis of the received information.
[0008] In addition, there may be further provided other systems to implement the present invention.
[0009] According to the invention, physical quantities of a ball at the stage of starting movement may be accurately measured.
[0010] According to the invention, a virtual sport system may produce a more accurate simulation result.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic diagram of the overall configuration of a virtual golf system according to one embodiment of the invention.
[0012] FIG. 2 is a detailed diagram of the internal configuration of a start sensor unit 100 according to one embodiment of the invention.
[0013] FIG. 3 is a detailed diagram of the internal configuration of a simulator 200 according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] In the following detailed description of the invention, references are made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures, or characteristics described herein may be implemented as modified from one embodiment to another embodiment without departing from the spirit and the scope of the invention. Furthermore, it shall be understood that the locations or arrangements of individual elements within each embodiment may be also modified without departing from the spirit and the scope of the invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the invention is to be taken as encompassing the scope of the appended claims and all equivalents thereof. In the drawings, like reference numerals refer to the same or similar elements throughout the several views.
[0015] Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to easily implement the invention.
[0016] Configuration of Overall System
[0017] FIG. 1 is a schematic diagram of the overall configuration of a virtual golf system according to one embodiment of the invention.
[0018] As shown in FIG. 1 , the virtual golf system may be configured to comprise a shot unit 10 , a start sensor unit 100 , a simulator 200 and a display device 300 .
[0019] First, the shot unit 10 according to one embodiment of the invention may be a part on which a golfer steps up to place and hit a golf ball when using the virtual golf system. The shot unit 10 may comprise a known swing plate, the tilt angle of which may be adjusted. It will be noted that when the invention is applied to other kinds of virtual sport systems, those skilled in the art may modify the configuration of the shot unit 10 and, if necessary, those of other components associated therewith to suit to the characteristics of the corresponding sports.
[0020] Next, the start sensor unit 100 according to one embodiment of the invention may perform a function to measure physical quantities of the golf ball at the stage of starting movement and transmit information on the physical quantities to the simulator 200 . To this end, the start sensor unit 100 may is comprise at least one, preferably a plurality of optical sensors (e.g., cameras, light sensors, etc.) or at least one, preferably a plurality of weight sensors. The detailed configuration of the start sensor unit 100 will be further described later with reference to FIG. 2 .
[0021] Next, the simulator 200 according to one embodiment of the invention may perform a function to receive from the start sensor unit 100 the information on the physical quantities of the golf ball at the stage of starting movement and perform a simulation of the movement of the golf ball using the information. The simulator 200 may be similar to conventional virtual golf simulation devices.
[0022] The simulator 200 may communicate with the start sensor unit 100 and the display device 300 , and may comprise a dedicated processor for virtual golf simulation. The dedicated processor may be provided with memory means and have numerical operation and graphics processing capabilities.
[0023] The configuration of the simulator 200 will be further described later with reference to FIG. 3 .
[0024] Lastly, the display device 300 according to one embodiment of the invention may perform a function to display a result of the numerical operation or graphics processing of the simulator 200 . The display device 300 may display images via display means, and may preferably be configured with a screen, which absorbs the impact of the hit golf ball and does not emit light directly, and a projector to output images on the screen.
[0025] Configuration of Start Sensor Unit
[0026] Hereinafter, the internal configuration of the start sensor unit 100 according to one embodiment of the invention and the functions of the respective components thereof will be described.
[0027] FIG. 2 is a detailed diagram of the internal configuration of the start sensor unit 100 according to one embodiment of the invention.
[0028] As shown in FIG. 2 , the start sensor unit 100 may be configured to comprise a start sensor 110 , a communication unit 120 and a control unit 130 .
[0029] According to one embodiment of the invention, at least some of the start sensor 110 , the communication unit 120 and the control unit 130 may be program modules to communicate with the simulator 200 . The program modules may be included in the start sensor unit 100 in the form of operating systems, application program modules or other program modules, while they may be physically stored in a variety of commonly known storage devices. Further, the program modules may also be stored in a remote storage device that may communicate with the start sensor unit 100 . Meanwhile, such program modules may include, but not limited to, routines, subroutines, programs, objects, components, data structures and the like for performing specific tasks or executing specific abstract data types as will be described below in accordance with the present invention.
[0030] First, the start sensor 110 may be configured with at least one, preferably a plurality of optical sensors (e.g., cameras, light sensors, etc.) disposed above the shot unit 10 , or at least one, preferably a plurality of weight sensors disposed on the top surface of the shot unit 10 .
[0031] The start sensor 110 may perform detection to decide whether a golf ball is disposed in a normal shot area on the shot unit 10 or to determine where the golf ball is disposed in the normal shot area on the shot unit 10 . The normal shot area may be a predetermined virtual area covered by the optical sensors above the shot unit 10 , or a predetermined substantial area covered by the weight sensors on the top surface of the shot unit 10 . In any case, the normal shot area may be divided into a plurality of sections. For example, if the start sensor 110 employs the optical sensors, the normal shot area on the shot unit 10 may be configured with a plurality of virtual sections corresponding to a plurality of coordinates at which an image of the golf ball may be detected. For another example, if the start sensor 110 employs the weight sensors, the normal shot area on the top surface of the shot unit 10 may be configured with a plurality of substantial sections at each of which the weight sensor is disposed.
[0032] First, the start sensor 110 may detect whether there is an image of the golf ball in the normal shot area or whether a weight corresponding to the golf ball (e.g., a weight similar to that of a common golf ball within a certain range) is applied in the normal shot area, by means of the sensors thereof. (That is, the start sensor 110 may perform detection to decide whether the golf ball is disposed in the normal shot area.) Thereafter, the start sensor 110 may transmit the corresponding data to the control unit 130 .
[0033] Further, if an image of the golf ball or a weight corresponding to the golf ball is detected with respect to a specific section (that is, the start sensor 110 may perform detection to determine where the golf ball is disposed in the normal shot area), then the start sensor 110 may transmit the corresponding data to the control unit 130 .
[0034] Meanwhile, it is possible that an image of the golf ball or a weight corresponding to the golf ball is detected with respect to two or more sections (apart from each other). (In many cases, this may occur when there is a detection error in the start sensor 110 or when an object other than the golf ball that a golfer intends to hit is disposed in the normal shot area.) In this case, the control unit 130 to be described below may only acknowledge, among the above corresponding data, those having been continuously received for or longer than a certain reference time duration.
[0035] Meanwhile, it is possible that an image of the golf ball or a weight corresponding to the golf ball is detected over two or more adjacent sections. In this case, the control unit 130 to be described below may only choose one of the two or more sections where a valid image size or weight of the golf ball is detected.
[0036] Next, the communication unit 120 may perform a function to mediate data transmission/receipt between the control unit 130 and the simulator 200 . Although there is no particular limitation on the communication modality that may be employed by the communication unit 120 , wired communication such as wired LAN communication and cable communication, or wireless communication such as wireless LAN communication, infrared communication, RF communication and Bluetooth communication may preferably be employed.
[0037] Lastly, the control unit 130 may perform a function to derive information on the physical quantities of the golf ball at the stage of starting movement on the basis of the data from the start sensor 110 and transmit it to the simulator 200 . Preferably, the control unit 130 may be a processor with simple data processing capability.
[0038] The control unit 130 may decide whether the golf ball is disposed in the normal shot area or determine where the golf ball is disposed in the normal shot area on the basis of the data from the start sensor 110 , and transmit the information to the simulator 200 .
[0039] Further, the control unit 130 may determine when the golf ball is hit on the basis of the data from the start sensor 110 . That is, when the data are no longer received which have been being received from the start sensor 110 indicating that an image or weight of the golf ball is detected with respect to a specific section, the control unit 130 may determine that point of time to be when the golf ball is hit, and transmit the information to the simulator 200 .
[0040] Further, the control unit 130 may also determine the section where the image or weight of the golf ball was detected immediately before the above point of time to be the section where the golf ball was located, and transmit the is location information thereon to the simulator 200 .
[0041] Configuration of Simulator
[0042] Hereinafter, the internal configuration of the simulator 200 according to one embodiment of the invention and the functions of the respective components thereof will be described.
[0043] FIG. 3 is a detailed diagram of the internal configuration of the simulator 200 according to one embodiment of the invention.
[0044] As shown in FIG. 3 , the simulator 200 according to one embodiment of the invention may be configured to comprise a simulation unit 210 , a data storage unit 220 , a communication unit 230 and a control unit 240 .
[0045] According to one embodiment of the invention, at least some of the simulation unit 210 , the data storage unit 220 , the communication unit 230 and the control unit 240 may be program modules to communicate with the start sensor unit 100 or the display device 300 . The program modules may be included in the simulator 200 in the form of operating systems, application program modules or other program modules, while they may be physically stored in a variety of commonly known storage devices. Further, the program modules may also be stored in a remote storage device that may communicate with the simulator 200 . Meanwhile, such program modules may include, but not limited to, routines, subroutines, programs, objects, components, data structures and the like for performing specific tasks or executing specific abstract data types as will be described below in accordance with the present invention.
[0046] First, the simulation unit 210 may receive information from the start sensor unit 100 and perform a virtual golf simulation on the basis thereof. That is, the simulation unit 210 may receive information on, for example, when the golf ball is hit, where the golf ball is disposed immediately before being hit, or whether the golf ball is disposed in the normal shot area, and utilize the information as input information of the simulation.
[0047] Examples of how the simulation unit 210 may utilize the above information are as follow:
[0048] 1. Calculating a Plane Angle, Elevation Angle and Speed of the Movement of a Golf Ball
[0049] Conventional virtual golf systems perform simulation assuming that the initial position of a golf ball is fixed in a location where a golfer usually hits the golf ball (e.g., the location of a tee). However, the position of the golf ball at the stage of starting movement is actually changed slightly every time, except when the golfer hits a tee shot. Therefore, if the simulation unit 210 accurately reflects in the simulation the information on where the golf ball is disposed immediately before being hit, then a plane angle (at which the initial movement of the golf ball is seen in the direction from the sky to the ground), elevation angle (at which the initial movement of the golf ball is seen from the side) and speed of the initial movement of the golf ball may be calculated more accurately. However, in order to calculate the angles of the initial movement of the golf ball, the data from other conventional sensors may be required together. Further, in order to calculate the speed of the initial movement of the golf ball, the data from other conventional sensors and the information on when the golf ball is hit may be required together.
[0050] 2. Calculating a Height of a Golf Ball
[0051] Even when the tilt angle of a swing plate does not become zero at the stage of starting movement of a golf ball, conventional virtual golf systems have not substantially considered that the height of the golf ball is accordingly changed. However, a more accurate simulation result may be produced if the simulation unit 210 accurately determines the height of the golf ball at the stage of starting movement, with reference to the information on where the golf ball is disposed immediately before being hit as well as the tilt angle of the shot unit 10 and the location of the tilt center, and reflects it in the simulation.
[0052] Meanwhile, if it is determined that the golf ball is disposed out of the normal shot area or an object other than the golf ball is disposed in the normal shot area, the simulation unit 210 may control the display device 300 to display a notification thereon.
[0053] Meanwhile, the simulation unit 210 may transmit to the display device 300 a control signal reflecting the movement of the golf ball in a graphical object or containing a video signal, so that the movement of the golf ball may be realistically displayed in the display device 300 .
[0054] Next, the data storage unit 220 may store information on the above-mentioned physical quantities of the golf ball at the stage of starting movement, or information required for the simulation. The data storage unit 220 may comprise a computer-readable recording medium.
[0055] Next, the communication unit 230 may perform a function to enable data transmission/receipt to/from the simulation unit 210 and the data storage unit 220 . Although there is no particular limitation on the communication modality that may be employed by the communication unit 230 , wired communication such as wired LAN communication and cable communication, or wireless communication such as wireless LAN communication, infrared communication, RF communication and Bluetooth communication may preferably be employed.
[0056] Lastly, the control unit 240 may perform a function to control data flow among the simulation unit 210 , the data storage unit 220 and the communication unit 230 . That is, the control unit 240 according to the present invention may control data flow into/out of the simulator 200 or data flow among the respective components of the simulator 200 , such that the simulation unit 210 , the data storage unit 220 and the communication unit 230 may carry out their particular functions, respectively.
[0057] Although it has been mainly described above that the system of the present invention is a virtual golf system, it will be apparent to those skilled in the art that the technical principle and configuration of the invention may be applied to all kinds of virtual sport systems (e.g., virtual baseball systems or virtual football systems) requiring simulation of the movement of a ball.
[0058] The embodiments according to the present invention as described above may be implemented in the form of program instructions that can be executed by various computer components, and may be stored on a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures and the like, separately or in combination. The program instructions stored on the computer-readable recording medium may be specially designed and configured for the present invention, or may also be known and available to those skilled in the computer software field. Examples of the computer-readable recording medium include the following: magnetic media such as hard disks, floppy disks and magnetic tapes; optical media such as compact disk-read only memory (CD-ROM) and digital versatile disks (DVDs); magneto-optical media such as floptical disks; and hardware devices such as read-only memory (ROM), random access memory (RAM) and flash memory, which are specially configured to store and execute program instructions. Examples of the program instructions include not only machine language codes created by a compiler or the like, but also high-level language codes that can be executed by a computer using an interpreter or the like. The above hardware devices may be changed to one or more software modules to perform the operations of the present invention, and vice versa.
[0059] Although the present invention has been described in terms of specific items such as detailed elements as well as the limited embodiments and the drawings, they are only provided to help general understanding of the invention, and the present invention is not limited to the above embodiments. It will be appreciated by a person of ordinary skill in the art that various modifications and changes may be made from the above description.
[0060] Therefore, the spirit of the present invention shall not be limited to the above-described embodiments, and the entire scope of the appended claims and their equivalents will fall within the scope and spirit of the invention.
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The present invention relates to a virtual sport system using a start sensor. One embodiment of the present invention provides a virtual sport system comprising: a hitting section from which a ball is hit; a start sensor unit which determines the physical quantity of the ball at the stage when the ball starts moving; and a simulation unit which receives, from the start sensor unit, information on the physical quantity, and simulates the motion of the ball on the basis of the information received.
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The present invention relates to distance-frequency transducers which operate according to the capacitive principle. Transducers of this type include a capacitor whose capacitance C varies as a function of distance between its plates. The latter in turn varies in dependence on the value of the parameter being measured.
BACKGROUND OF THE INVENTION
Distance-frequency transducers are required in many fields including electrical control and measurement. Specifically it is often desirable to have a distance-frequency transducer which encompasses changes in distance of from approximately 0.5 to 10 mm and whose output frequency changes by a factor of more than 10 for such changes in distance.
THE INVENTION
In accordance with the present invention, the capacitance of a capacitor having at least one electrode movable with respect to another in accordance with the value of the parameter being measured is made part of an RC oscillator circuit. Preferably, an astable multivibrator is used as RC oscillator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating the operating principles of the present invention;
FIG. 2 is a more detailed circuit diagram of the RC oscillator of the present invention;
FIG. 3 shows the variation of voltages at selected points of the circuit of FIG. 2 during one cycle;
FIG. 4 is a partially sectional view of the pressure pickup used as measuring capacitor in the present invention;
FIG. 5 is an embodiment utilizing a pressure pickup having a corrugated membrane;
FIGS. 6, 7 and 8 show alternate mounting arrangements for the pressure pickup and the oscillator;
FIG. 9 is a diagram illustrating the layout of the printed circuit board utilized in FIG. 8;
FIG. 10 illustrates an embodiment wherein the measuring capacitor and RC oscillator are enclosed within a single housing;
FIG. 11 shows an embodiment of the present invention similar to that of FIG. 5 but producing an output having an asymmetrical on/off ratio; and
FIG. 12 shows the variation of output frequency as a function of pressure in one embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The basic principle of the present invention is illustrated in FIG. 1. Two plates 11 and 12 are shown which constitute the electrodes of a capacitor. The capacitance C S varies as a function of the distance s between the plates. Specifically one of the plates of the capacitor may be coupled to a member of an internal combustion engine, such as, for example, the membrane of a pressure pickup. Electrodes 11 and 12 are connected to an astable multivibrator 13 which is constructed in the integrated circuit technique and furnishes an output frequency which is inversely proportional to the capacitance and therefore directly proportional to the distance between the plates.
In a practical embodiment of such a variable capacitor, relatively small capacitances C S in the region of 0.5 to 50 pf result. Since the capacitance changes are so small, the RC oscillator 13 must be very carefully designed so that the desired frequency changes are not masked by interference effects such as parasitic circuit capacitances, temperature variation of the circuit, leakage currents, etc.
An RC oscillator suitable for integrated circuit construction is shown in FIG. 2. This type of construction fulfills the above-mentioned requirements, is relatively inexpensive, has a linear output which is stable with respect to temperature changes and not sensitive relative to supply voltage variation.
The RC oscillator consists of a series connected circuit of an integrator and a Schmitt trigger circuit having a suitable feedback.
The circuit between terminals 1 and 2 is a field effect operational amplifier connected as an integrator. The capacitance C S which depends on the distance between plates, and the parasitic capacitance C p assumed to be in parallel with it, together with the resistance R 2 determine the integration time constant. This is given by equation 1.
The capacitance C K of the small trimmer capacitor allows compensation for the undesired effect of C p on the characteristic transfer curve. This is described in greater detail below.
The circuit between reference numerals 2 and 4 constitutes a rapidly acting comparator which, with the aid of resistors R 3 and R 4 , forms a Schmitt trigger having a defined hysteresis. Because the voltage supply is to be asymmetrical, two resistors R 1 are used as voltage dividers to fix a potential at a terminal 5 to which the potentials U B and chassis potential are symmetrical.
Feedback from terminal 4 causes a square wave voltage symmetrical to the voltage at terminal 5, having an on-off ratio of 1:1 and a frequency f varying as a function of C Sn to be generated at that terminal.
FIG. 3 shows the voltage variation with respect to time at terminals 4 and 2 as well as the thresholds U 20 and U 2u at which the Schmitt trigger switches.
The voltage U 2 has a discontinuity at each switching point. This desired effect may be ascribed to capacitor C K which causes a lead in the voltage U 2 and thus compensates for the delayed linear rise of U 2 resulting from capacitor C p . (For C p =C k =0, the variation of voltage U 2 would be along the dashed line.)
The frequency of the oscillator is given by equation 2.
It is independent of supply voltage U B and the effect of capacitance C p can be eliminated by correct dimensioning of capacitor C K . The desired value of C K is given in equation 3. When C s is inversely proportional to the distance between the plates, the frequency will be directly proportional to this distance.
One embodiment of a capacitive distance sensor and its connection to the circuit of FIG. 2 is shown in FIG. 4.
Capacitor plate E1 is circular and is surrounded by a ring-shaped protective electrode E5.
The two electrodes are constituted by a copper coating on a printed circuit board P. The electrodes are insulated relative to metallic housing G which is at ground or chassis potential.
The circular electrode E2 is movable along the path s. The variation in distance s is transmitted by a bolt B which is mounted in a bearing in the housing. The capacitance between E1 and E2 is thus changed. E2 is insulated relative to the bolt. Contact takes places by means of flexible wires. Ring electrode E5 serves two purposes:
It is approximately the same potential as E1 and thus prevents leakage currents from E1 to the housing. Furthermore, the presence of the ring electrode causes a homogenous electric field to exist between E2 and E1, even at the edge of E1. The variation of C S is thus inversely proportional to the distance variation.
Because of the particular characteristics of the circuit used, the considerable capacitances between E2 and G (ground potential), E1 and G, E1 and E5 have no effect on the frequency.
Copper braid shielding which covers the measuring capacitor and may be extended to cover the complete circuit prevents both radiation to and radiation from the equipment.
Other embodiments of the present invention are illustrated in FIGS. 5 to 11. In each of these, the capacitance C is formed by a metallic membrance of a pressure pickup, the membrance being movable as a function of pressure relative to a second electrode. A concentric corrugated membrane pressure pickup may be used whose upper surface constitutes one of the two capacitor electrodes. It is positioned relative to the second electrode in such a way that changes in pressure cause a change in the distance between the two electrodes.
In a further embodiment the second electrode may have an inner area in which at least one zone is provided which is free of the conductive electrode material. The equipment can be adjusted to have the desired (e.g. linear) variation of oscillator frequency as a function of pressure by means of such a zone. Preferably, the pressure pickup is surrounded by two parts of the housing (G1, G2) which are mounted from the top and the bottom on a printed circuit board on which the second electrode and the oscillator circuit are also mounted. A printed circuit board made of an insulating material may also contain further electrical components applied, for example, by vacuum deposition or metalization.
In a further embodiment of the invention, a trimmer capacitor may be connected in parallel to the measuring capacitance of the pressure pickup and, further, a second capacitor may be provided which is connected in parallel to the charging resistor of the integrator.
In the embodiment of FIG. 5, a plate I of insulating material (fiberglass-epoxy) insulates housing parts G1 and G2 from each other. The housing parts G1 and G2 may be made of aluminum, zinc, or brass. Both parts of the housing are pasted to the plate. Electrode films E1, E5 of highly conductive material are applied to the top surface of the plate. A copper layer having an etched structure applied by a thick film or thin film technique may be used. Electrode connectors 5 and 1 pass tightly through the bottom of the housing.
Housing part G1 is connected at terminal 10 to ground potential. Contact with electrode E2 (the pressure pickup) is made via pin 2 and the upper part G2 of the housing as well as terminal A2. This method of making contact with electrode E2 via G2 has many advantages as to construction and manufacture. However, it must be noted that the upper part G2 of the housing is not at ground potential. It carries a high frequency (less than 100 kHz) AC voltage having a DC component. Capacitive pickup by neighboring circuits may occur. The pressure connection to the intake pipe of an internal combustion engine takes place at A1 or A2 via an insulating flexible tube.
The electronic circuit can either be fastened to a printed circuit board underneath the pressure pickup by means of pins 1, 2, 5, and 10 and provided with a protective cover which also constitutes electrical screening, or the pressure pickup can be soldered onto a printed circuit board as would be a power transistor, the circuit then being mounted right next to the pressure sensor on the same board (FIG. 6).
An alternate embodiment is shown in FIG. 8. The printed circuit board with the circuit evaluating the pressure applied to the pressure pickup and, if necessary, additional electronic circuits, is utilized directly as the board carrying the electrode in the pressure pickup. Housing parts G1 and G2 are placed onto the board from above and below. Connection to the electrodes is made by conductive strips in an identation in housing G2 which is then sealed with a potting compound. It is to be particularly noted that in this embodiment the threaded nipple of the pressure pickup is screwed into the housing but insulated by a threaded bushing. The upper part of the housing may be grounded for this embodiment, the pressure pickup being connected by means of a shielded wire and the threaded nipple. Capacitive pickup by other cicuit parts can thus be substantially eliminated.
FIG. 9 shows the layout of a pressure pickup plate for the embodiment of FIG. 8.
As shown in FIG. 7, the pressure sensor is used in conjunction with a separately mounted electronic circuit, shielded wiring (two individually shielded leads) being used to form the electrical connection.
In the embodiment of FIG. 10, the pressure pickup and the associated electronic circuits are all built into one housing. The board carrying the electrode and the board carrying the circuit are separate units. The connection to the pressure pickup which is insulated from the housing is effected by a soldered pin and a thin spiral connecting wire.
The associated electronic circuitry was explained above with reference to FIG. 1. A more detailed diagram is illustrated in FIG. 5. In FIG. 5, IS1 is an operational amplifier having a field effect input, IS2 is a rapidly acting double comparator whose second stage acts as a driver without feedback. The output (open collector) can be connected to the supply voltage of the subsequent logic circuits by means of resistor R 8 and is thus compatible with different logic systems. The on/off ratio of the rectangular output signal is one to one, the frequency f being a measure of the pressure.
An additional capacitor can be used to make the second comparator a monostable multivibrator (FIG. 11). In this case, not only the frequency but also the average value of the output voltage is a measure of the pressure. Specifically, the output voltage is given by equation 4.
A fine adjustment of the slope Δf/Δp of the characteristic curve f(P) can be made either by the resistance ratio R 3 /R 4 or the absolute value of resistor R 2 . The frequency f 0 is adjusted by movement of the pressure pickup through the threaded nipple. The capacity C K is adjusted only once for each layout (see FIG. 9). An individual adjustment of C K is generally not required.
In an experimentally tested embodiment, the construction of FIG. 8 with the layout of FIG. 9 was utilized.
The pressure pickup had a diameter of 38 mm, its characteristic being ΔS/ΔP=0.2 cm/bar.
Values of circuit components are listed in Table 1.
The capacitance C K is constituted by conductive strips parallel to resistor R 2 .
The curve of FIG. 12 shows the characteristic curve of f as a function of pressure p achieved in the above-described embodiment. ##EQU1##
TABLE I______________________________________Circuit Component Values:______________________________________R.sub.1 = 2.2kΩ R.sub.2 = 2.2MΩ 1S.sub.1 = LF 357R.sub.3 = 50kΩ R.sub.4 = 100kΩ 1S.sub.2 = LM 319R.sub.5 = 5.1kΩ R.sub.6 = 470kΩR.sub.7 = 470kΩ C.sub.1 = 33nF______________________________________
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The distance-frequency transducer includes a capacitor whose capacitance changes as a function of movement of one electrode relative to the other. The movement is controlled by the parameter to be measured, as, for example, the pressure in a pressure pickup. The capacitance determines the frequency of an RC oscillator. The output frequency of the oscillator can be calibrated directly in pressure units.
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TECHNICAL FIELD
The present invention relates to a method for and apparatus for enabling repeatable accurate alignment of a communication antenna that is attached to antenna brackets without the need for a technician, rigger or climber to come in direct contact with the antenna itself.
BACKGROUND TO THE INVENTION
Antenna structures are used by cellular communications network/service providers to receive antennas for transmission and reception of radio signals. A typical antenna structure comprises a tower, one or more antenna brackets attached on the tower top, so that one or more antennas are attached on the antenna brackets. Usually, the tower is firstly assembled at the point of installation and then the antenna brackets are mounted on the tower itself. Antennas are attached to the antenna brackets by means of mounting bolts and screws or other securing means, defining a specific horizontal (azimuth) and vertical (tilt) directionality for the transmission and reception of radio signals.
To achieve high network performance, provide high quality radio link transmissions and receptions and ensure high spectrum efficiency, the panel antennas must be aligned with minimum inaccuracy (less than ±1°) to the specified horizontal (azimuth) and vertical (tilt) directionality angles provided by the radio planning process and antenna installation work orders. Accurate alignment of panel antennas is of paramount importance in a competitive wireless communication industry as even small errors in azimuth and tilt alignment (more than ±5° for azimuth and more than ±1° for tilt) can seriously degrade radio network quality. See, for example, the reference paper “Impact of Mechanical Antenna Downtilt on Performance of WCDMA Cellular Network” and also the paper “Impacts of Antenna Azimuth and Tilt Installation Accuracy on UMTS Network Performance” by Bechtel Corp.
Several prior art solutions are currently available for accurate alignment of antennas azimuth and tilt. For example, US20090021447 and US20110225804 describe a device for measuring the orientation of an antenna in three directions, i.e. azimuth, tilt and roll. The device is directly secured to an antenna and displays the measured values for azimuth, tilt and roll, allowing a user to accurately align an antenna to the desired directions. A deficiency of the prior art is that such a device cannot be employed in antenna structures having one or more antennas covered under a radome, due to the fact that antenna accessibility from an antenna technician, rigger or climber is not possible or generally limited (examples of such antenna structures are disclosed in US20050134512A1 & WO2011042226). As a result, the use of the measurement devices described in US20090021447 and US20110225804 are not applicable to serve the purpose of accurate alignment of antenna structures covered under a radome.
Furthermore, due to modern networks' dynamic nature, continuous antenna azimuth and tilt re-adjustment during the lifecycle of a base station site (for one or more antennas) is required; therefore, the antenna brackets, the antennas or the antenna structure itself should be capable to provide the suitable means for facilitating such needs. Each antenna is designed to serve a specific area, namely a cell or sector. Cell direction, i.e. antenna azimuth & tilt, is produced by modeling multiple aspects of radio access technology as well as accounting for radio propagation science by using radio planning tools. The main aim of the radio network planning process is to provide optimum performance for the radio network in terms of coverage, capacity and quality. The network planning process and base station site design criteria vary from cluster to cluster depending upon the dominating factor, which is optimum performance. Said coverage may include defining the coverage areas, service probability and related signal strength; said capacity may include subscriber density and traffic profiles in the coverage region and whole area, availability of the frequency bands, frequency planning methods, and other information such as guard band and frequency band division; said quality is related to radio interference metrics such as signal to noise ratio. Since all radio network performance aspects are fully dynamic, the radio network planning process that selects antenna directionality at installation phase cannot ensure that the selection criteria (i.e. capacity, coverage and quality) will remain the same after a period of time. Usually, the antennas are installed and operated for at least 7 to 10 years or even more. This fact by itself, means that the antenna azimuth and tilt directions must often change during the base station site lifecycle by re-adjustment means. Ideally, antenna azimuth and tilt re-adjustment should be considered at least once every six months for every antenna in the network, especially in urban and heavy urban areas where the demands on capacity and quality of radio base station clusters are continuously shifting.
When antenna system azimuth and tilt re-adjustment is to be performed, such re-adjustment should take place without the need to climb on the tower top, so as to avoid complicated operations of high opex (operational expediture) costs (due to climbing) and also ensuring health and safety at work for antenna technicians, riggers and climbers. It is well known that human exposure on high electromagnetic fields is an issue to be considered by the network service providers for those working in close proximity to radiating antenna systems. Climbing on the tower top in order to set or re-adjust the directionality of antennas is not avoided by use of the devices disclosed in US20090021447 and US20110225804 as they do not provide the means for such operations. However, when such devices are not used, the problem of antennas azimuth and tilt accurate alignment for any directionality re-adjustment by remote operation remains.
In the case where there is a need to satisfy both antenna alignment accuracy and remote re-adjustability (with no climbing) with accuracy, an electromechanical apparatus that performs both actions needs to be deployed. A single pivot axis antenna bracket that offers remote azimuth adjustment by electromechanical means is disclosed in WO2007093689A1. However, a deficiency of such prior art is that such an antenna bracket cannot satisfy the alignment accuracy required by the radio planning process and antenna system installation work orders without use of devices disclosed in US20090021447 and US20110225804. This is due to the fact that the proposed electromechanical system attached on the antenna bracket does not provide absolute azimuth, tilt and roll measurement means. The result of this is that all of the disadvantages introduced by use of US20090021447 and US20110225804 (as described in the previous paragraphs) follow as disadvantages also for apparatus of WO2007093689A1. Furthermore, a single pivot axis antenna system that offers remote azimuth adjustment by electromechanical actuation but also attempts to provide absolute azimuth, tilt and roll measurement means is also disclosed on US20090195467. However, a deficiency of such prior art is that such a solution utilizes an earth gravitational magnetic field sensor which, by default, introduces inaccuracy due to magnetic field disturbances caused from the antenna systems, the antenna brackets and the antenna structure itself (i.e. soft and hard iron effects). Therefore, such a solution, although it offers both antenna system alignment accuracy and remote re-adjustability with accuracy, does not address the issue of high overall accuracy.
The deficiencies exemplary of the apparatus of WO2007093689A1 and US20090195467 are applicable not only in these documents, but also when antenna systems are attached on antenna brackets that utilize more than one pivot axis for horizontal (azimuth) alignment and movement. In a particular example of antenna system directionality, two antennas may need to have the same horizontal direction or the same azimuth angle. In order to align and direct both antenna systems to the same azimuth angle, prior art US20060087476 proposes a dual pivot axis antenna bracket for installation on a triangular tower utilizing antenna sector frames. WO2011042226 (GB2474605) proposes a dual pivot axis antenna bracket for installation on a monopole structure by utilizing a collar. This prior art provides the capability, due to the dual pivot axis antenna bracket attached on the antenna structure, to offer full motion freedom on the antenna system(s) (needed for future horizontal azimuth re-adjustments) by maximizing the allowable antenna system horizontal (azimuth) movement range.
It is the purpose of the present invention to overcome or at least mitigate at least some of the aforementioned disadvantages of the prior art. In particular, it is the purpose of the present invention to propose a method for and apparatus for enabling the accurate, and repeatably accurate, alignment of communication antenna systems that are attached on either single or dual pivot axis antenna brackets, without the need for a technician, rigger or climber to come in direct contact with the antenna system itself.
SUMMARY OF THE INVENTION
Aspects and preferable features of the invention are defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
An example of an antenna alignment apparatus and method according to the present invention will be described with reference to the accompanying figures in which:
FIG. 1 a is a schematic side view representation of a single sector antenna structure according to an embodiment;
FIG. 1 b is a schematic plan view representation of a single sector antenna structure according to an embodiment;
FIG. 2 is a perspective view of a reference point system for a single sector antenna structure;
FIG. 3 a is a perspective view of an azimuth and tilt plane;
FIG. 3 b is a perspective view of an azimuth and roll plane;
FIG. 3 c is a schematic perspective view of an antenna system showing tilt and roll angles;
FIG. 4 a is a plan view of a single antenna sector in a ‘home position’;
FIG. 4 b is a plan view of a single antenna sector after anticlockwise rotation from the position shown in FIG. 4 a;
FIG. 4 c is a plan view of a single antenna sector after clockwise rotation from the position shown in FIG. 4 a;
FIG. 5 a is a schematic plan view representation of an antenna system comprising three antenna sectors;
FIG. 5 b is a further schematic plan view representation of an antenna system comprising three antenna sectors;
FIG. 6 is a flow diagram outlining antenna system installation method steps according to an embodiment;
FIG. 7 is a perspective view of an antenna sector system according to an embodiment.
FIG. 8 is a flow diagram outlining the steps of tilt adjustment of an antenna;
FIG. 9 is a flow diagram outlining the steps of azimuth adjustment of an antenna;
FIG. 10 is a cut-away diagram of an apparatus according to an embodiment;
FIG. 11 is a perspective view of an antenna and apparatus of FIG. 10 .
DETAILED DESCRIPTION
FIGS. 1 a and 1 b are schematic diagrams of an antenna 500 mounted on an antenna structure 100 ′. The joints described below in relation to FIGS. 1 a and 1 b can, one some embodiments, allow for mechanical adjustment of the position of antenna 500 relative to the antenna structure 100 in three dimensions (i.e. mechanical movement of antenna 500 so as to adjust the radiation pattern direction of the in azimuth, tilt and roll planes). However, in some embodiments, adjustment of tilt and roll is achieved electrically, rather than mechanically, by controlling the dipole feeding lines.
The antenna structure comprises central portion 100 which is attached to a first antenna bracket mounting formation 200 . The first antenna bracket mounting formation 200 is attached to single pivot axis mounting formation 300 . The single pivot axis mounting formation 300 is attached to a second antenna bracket mounting formation 400 , and the second antenna bracket mounting formation 400 is attached to a panel antenna system 500 . The first antenna bracket mounting formation 200 is mounted to the central portion 100 by central top and bottom joints A′ and B′ respectively and is mounted to the single pivot axis mounting formation 300 by central top and bottom joints A′″ and B′″ respectively. The first antenna bracket mounting formation 200 also comprises the joints A″ and B″ that serve the purpose of defining or setting the vertical (tilt) heading of the antenna system with respect to the antenna structure central vertical axis 100 ′.
The single pivot axis mounting formation 300 is mounted to the first antenna bracket mounting formation 200 by central top and bottom joints C′ and D′ respectively. The single pivot axis mounting formation 300 is mounted to the second antenna bracket mounting formation 400 by central top and bottom joints C′″ and D′″ respectively. The single pivot axis mounting formation 300 also comprises central joints C″ and D″ that define the horizontal (azimuth) directionality of the antenna system (with respect to the perpendicular lines as shown in FIG. 1 a ) by the respective central top mounting joints A′, A′″, C′, C″ and the central bottom mounting joints B′, B′″, D′, D″ with respect to the antenna structure central vertical axis 100 ′.
The second antenna bracket mounting formation 400 is mounted to the antenna system by central top and bottom joints E″ and F″ respectively. The second antenna bracket mounting formation 400 is mounted to the single pivot axis mounting formation 300 by central top and bottom joints E′ and F′ respectively. In order to position the horizontal (azimuth), vertical (tilt) and adjacent vertical (roll) heading of antenna system 500 a known, pre-calibrated, 3-dimensional position (herein referred to as “home position”) with respect to the antenna structure central vertical axis 100 ′, the top mounting central joints A′, A′″, C′, C″, C′″, E′ and E″ are placed in line, thus forming a central line A′-E″ 201 . This central line 201 is perpendicular to the central vertical axis 100 ′. The same applies for the bottom mounting central joints B′, B′″, D′, D″, D′″, F′ and F″ which form the central line B′-F″ 202 , where this central line 202 is parallel to the central line 201 and perpendicular to the central vertical axis 100 ′.
Additionally, the top mounting central joints A′, A″, A′, C′, C″, C″, E′ and E″ and the respective bottom mounting central joints B′, B″, B′″, D′, D″, D′″, F′ and F″ are in pairs forming the respective central lines A′-B′ 203 , A″-B″ 204 , A′″-B′″ 205 , C′-D′ 206 , C″-D″ 207 , C′-D′″ 208 , E′-F′ 209 and E″-F″ 210 . These central lines are all parallel to the central vertical axis 100 ′. In this way, the first antenna bracket mounting formation 200 is in line with the single pivot axis mounting formation 300 , the single pivot axis mounting formation 300 is in line with the second antenna bracket mounting formation 400 and the second antenna bracket mounting formation 400 is in line with the antenna system 500 and, all together, are absolutely perpendicular to the central vertical axis 100 ′. Therefore, the horizontal (azimuth), vertical (tilt) and adjacent vertical (roll) heading of the antenna system 500 is at a known, pre-calibrated, 3-dimentional “home position”, with respect to the antenna structure central vertical axis 100 ′.
FIG. 2 shows a perspective view of a reference point system. Four points J, K, L, M form a line J-M 601 which is perpendicular to the central vertical axis 100 ′ of the antenna structure. Four points J′, K′, L′, M′ form a line J′-M′ 701 which is perpendicular to the central vertical axis 100 ′ of the antenna structure. Additionally, points J, K, L, M, and the respective points J′, K′, L′, M′ are in pairs forming the respective lines J-J′ 671 , K-K′ 672 , L-L′ 673 , M-M′ 674 . These lines are all parallel to the central vertical axis 100 ′.
In order to align the central bottom mounting joints B′, B′″, D′, D″ that are located on the first antenna bracket mounting formation 200 with the single pivot axis mounting formation 300 up to the pivot axis central mounting joint D″ to points J, K, L, M, the respective lines B′-J, B′″-K, D′-L and D″-M need to be formed in pairs. By ensuring that the lines B′-J, B′″-K, D′-L and D″-M are all parallel, and also parallel to the antenna structure central vertical axis 100 ′, analysis and the imaginary transfer of the first antenna bracket mounting formation 200 and the single pivot axis mounting formation 300 up to the pivot axis central mounting joint D″ (and vice versa) is achieved for horizontal (azimuth), vertical (tilt) and adjacent vertical (roll) heading in the reference point system.
With the aid of FIG. 1 a , FIG. 1 b and FIG. 2 , a method of aligning an antenna system to a “home position”, as well as a method of transferring the first antenna bracket mounting formation 200 and the single pivot axis mounting formation 300 up to the pivot axis central mounting joint D″ to a reference point system with respect to an antenna structure has been described. As a result, and with reference to FIG. 2 , the antenna system “home position” heading can be transferred and assessed on the reference point system, when the bottom mounting central joints B′-F″ form a line. Since this line determines that the antenna system is in “home position”, the J-M line on the reference point system can be assumed to represent the antenna system “home position”. This is ensured by appropriate installation procedures when the lines J-M and B′-D″ are parallel.
In order to determine the antenna system “home position” heading in the horizontal (azimuth), vertical (tilt) and adjacent vertical (roll) directions in terms of absolute values (as well as relative values as described above), the J-M line horizontal (azimuth), vertical (tilt) and adjacent vertical (roll) heading needs to be measured with respect to the grid or true north (i.e. azimuth determination) and with respect to the central earth gravity axis (i.e. tilt and roll determination) on the reference point system. Several prior art solutions are currently available for such measurements. For example, US20090021447 and US20110225804 describe devices for the accurate measurement of the orientation of an antenna system in three directions, i.e. azimuth, tilt and roll, which can be used for the purpose described herein.
After completing the antenna system heading “home position” measurements in the three directions, i.e. azimuth, tilt and roll, with respect to the grid or true north (to be called herein as GTN) and with respect to the central earth gravity axis (to be called herein as CGA), the next step is to determine the necessary actions to be performed in order for the antenna system heading to be aligned to desired azimuth, tilt and roll directionality angles provided by the radio planning process and installation work orders (to be referred to herein as “planned position”). Although the first configuration of our antenna system in the “home position” may take any azimuth, tilt and roll directionality angle in space after installation completion, for simplicity purposes assume that the “home position” angles of the antenna system heading are as follows:
antenna system azimuth in “home position”=α° HP antenna system tilt in “home position”=β° HP antenna system roll in “home position”=γ° HP
Attempting to re-adjust the antenna system heading from “home position” to “planned position” results in an antenna system heading “home position” offset of α1° OFF, β1° OFF and γ1° OFF degrees for azimuth, tilt and roll respectively. Therefore, in order to achieve alignment of the antenna system “home position” heading to the desired “planned position” heading one may simply assume that the “planned position” angles of the antenna system heading are as follow:
antenna system azimuth in “planned position”=α° HP+/−α1° OFF=α° PP antenna system tilt in “planned position”=β° HP+/−/β1° OFF=β° PP antenna system roll in “planned position”=γ° HP+/−γ1° OFF=γ° PP
In the exemplary first configuration (as described with the reference to FIG. 1 a and FIG. 1 b ) in order to meet the antenna system azimuth in “planned position”, a rotation of the antenna system group, to be called herein as ASG, comprising the antenna system and its respective supporting parts, around the central vertical axis 100 ′), (referred to herein as CVA), needs to be performed. Alternatively or additionally, only the antenna system can be rotated, around the single pivot axis mounting formation 300 . The antenna system group or the antenna system only needs to be rotated clockwise or counterclockwise by the offset α1° OFF in order to meet the antenna system azimuth in “planned position”. In the case of rotating the antenna system group by the offset α1° OFF, it can be realized that, after the re-adjustment of azimuth (planned azimuth=α° HP+/−α1° OFF=α° PP), the initial antenna system “home position” measurement taken for tilt (tilt=β° HP) and roll (roll=γ° HP) angles, are no longer valid and need to be re-measured or re-calculated if the tilt angle β° HP≠0° and the roll angle γ° HP≠0°. This is due to the fact that the “home position” tilt (tilt=β° HP where β° HP≠0°) and roll (roll=γ° HP where γ° HP≠0°) angles on the antenna system group have been measured with respect to the central gravity axis (CGA) for a specific antenna system group (ASG) azimuth heading with respect to the central vertical axis 100 ′ of the antenna structure. The same issue arises when the antenna system is rotated around the single pivot axis mounting formation 300 .
By way of example, let us assume that the antenna system group “home position” is headed at an angle α° HP with respect to grid or true north (GTN). When the antenna system azimuth is offset (provided by the radio planning process and installation work orders) at +90° (i.e. α1° OFF=+90°) from “home position” and the tilt angle and roll angles occupy “home position” (tilt=β° HP where β° HP≠0° roll=γ° HP where γ° HP≠0°), then the antenna system tilt and roll angles at the “planned position” azimuth angle (planned azimuth=α° HP+90°=α° PP) shall be equal to γ° HP and β° HP respectively. This is due to the fact that, when the antenna system is rotating its azimuth heading from “home position” to “planned position”, the antenna system performs this movement over the central vertical axis (CVA) of the antenna structure. On top, knowing that the tilt plane and roll plane, by the aforementioned installation, are always perpendicular to the azimuth plane and always perpendicular to the central vertical axis (CVA) of the antenna structure, the antenna system heading on tilt plane will always be perpendicular to the antenna system heading on roll plane. The result of this is that, for every azimuth heading offset of +90° or −90° from the “home position”, the tilt and roll angles with respect to the central gravity axis (CGA) will reverse (i.e. the “home position” tilt angle β° HP where β° HP≠0° and the “home position” roll angle=γ° HP where γ° HP≠0°) such that the antenna system tilt and roll angles at the “planned position” azimuth angle (planned azimuth=α° HP+/−90°=α° PP) shall be equal to γ° HP and β° HP respectively).
Similarly, when the antenna system azimuth offset (provided from the radio planning process and installation work orders) is +180° or −180° (i.e. α1° OFF=+/−180°) from “home position” and the “home position” tilt angle=β° HP where β° HP≠0°) and the “home position” roll angle=γ° HP where γ° HP≠0°), then the antenna system tilt and roll angles at the “planned position” azimuth angle (planned azimuth=α° HP+/−180°=α° PP) shall be equal to −β° HP and −γ° HP respectively. Therefore, in order to achieve accurate re-alignment of the antenna system “home position” heading to the desired “planned position” heading for all three dimensions of interest, it can be realized that one cannot simply assume the calculation of the offset introduced for azimuth, tilt and roll angles in the “planned position”, having as reference the installed antenna system or antenna system group in “home position”. This assumption can only be applied in the case that the antenna structure, and more specifically, the central vertical axis (CVA) of the antenna structure after its installation, coincides with the central gravity axis (CGA) that defines the tilt and roll angles of the antenna system or antenna system group in the “home position”, i.e.:
antenna system azimuth in “home position”=α° HP antenna system tilt in “home position”=0° antenna system roll in “home position”=0°
Since it cannot be ensured from any installation procedure that the installation of an antenna structure, and more specifically the antenna structure's central vertical axis (CVA), will coincide with the central gravity axis (CGA), and since such installation imperfections will always be present in cellular communications network roll-outs, one needs to take into account the installation imperfections introduced and calculate the “home position” tilt angle for tilt=β° HP where βHP≠0° and the “home position” of roll angle for roll=γ° HP where γ° HP≠0°, for any azimuth angle at “planned position” displaced in between 0° and 360° on the azimuth plane with respect to “home position” in order to achieve antenna system re-alignment accuracy for any purpose.
The three dimensional antenna system alignment problems described in the previous paragraphs for azimuth re-adjustment can be overcome when an antenna system alignment algorithm, defining the relationship of the antenna system heading from “home position” to “planned position” for azimuth, tilt and roll heading angles, is applied at antenna system installation and any antenna system re-adjustment phase. FIG. 3 a and FIG. 3 b show perspective views of azimuth and tilt plane and azimuth and roll plane respectively. Specifically, FIG. 3 a shows the antenna system group azimuth heading α° HP (depicted as AB on azimuth plane 1000 ) in “home position” with respect to the antenna system tilt angle (β° HP) on tilt plane 2000 in “home position”, the central gravity axis CB and its offset with the antenna structure central vertical axis AC (indicating the tilt installation imperfection angle β HP, with respect to the central gravity axis CB).
FIG. 3 b shows the antenna system group azimuth heading α° HP (shown as AB′ on azimuth plane 1000 ) in “home position” with respect to the antenna system roll angle (γ° HP) on roll plane 3000 in “home position”, the central gravity axis CB′ and its offset with the antenna structure central vertical axis AC (indicating the roll installation imperfection angle γ° HP with respect to the central gravity axis CB). Since azimuth, tilt and roll planes are, due to care during installation, perpendicular to each other and parallel to the antenna structure central vertical axis (CVA), one may form a three-dimensional view of the antenna system group tilt and roll installation imperfections with respect to the central gravity axis (CGA) for any azimuth angle applied clockwise or counterclockwise around the central vertical axis (CVA).
FIG. 3 c shows the antenna system group tilt and roll angles (β° HP and γ° HP) for antenna system group azimuth heading α° HP (depicted as AB and AB′ on the perpendicular cross section of tilt and roll planes on the azimuth plane respectively). For any antenna system group azimuth heading α° PP at “planned position”, AZ′ and AZ depict the newly formed tilt and roll angles respectively at α1° OFF away from their “home position”. In order to calculate the newly formed tilt and roll angles at α1° OFF away from their “home position”, one needs to form the projections of Z′ and Z points on AB and AB′ lines respectively. After doing so, the lines AD′ and AD are formed, thus indicating the newly introduced tilt and roll angles with reference to the tilt and roll initial angles (depicted by the AB and AB′ lines) at α1° OFF away from their “home position”. In this way, the newly formed tilt and roll angles “home position” β1° HP and γ1° HP at α1° OFF away from their initial setting can be calculated. Completing the antenna system three dimensional alignment from “home position” to “planned position”, by having the azimuth at α° PP, the tilt and roll angles in the “home position” now become:
TILT @ “home position” after α1° OFF=β1° HP
ROLL @ “home position” after α1° OFF=γ1° HP
Therefore, in order to achieve accurate alignment from the antenna system “home position” to the desired “planned position”, one may calculate the “planned position” angles of the antenna system heading as follow:
antenna system azimuth in “planned position”=α° HP+/−α1° OFF=α° PP antenna system tilt in “planned position”=β1° HP+/−β1° OFF=β° PP antenna system roll in “planned position”=γ1° HP+/−γ1° OFF=γ° PP
It is to be noted that the radio planning process and installation work orders do not necessarily provide antenna system roll heading angles as they always assume successful antenna system installation on the roll plane and, as a result, assume roll directionality to be 0° with respect to the central gravity axis (CGA). Since an antenna system roll heading other than 0° would only impact the polarization angle of the antenna system dipoles (i.e. E-Field directionality), such a radio planning parameter and thus roll angle further degrees of freedom for installation error compensation are not discussed herein. However, any roll angle re-adjustment methods need not be considered standalone, because they are relevant to the antenna system azimuth and tilt heading at “planned position” when and if needed. The method of the present invention are particularly beneficial when applied to a dual pivot axis system in order to calculate installation imperfections of an antenna structure.
FIG. 4 a shows a plan view of a single sector antenna system in “home position”. Whilst the ‘home position’ of the antenna is shown in FIG. 4 in the azimuth direction, it will be appreciated that in such a ‘home position’, the joints of the antenna are aligned as discussed above to ensure the tilt and roll planes are perpendicular to the azimuth plane. The antenna structure comprises a first antenna bracket mounting formation 200 which is attached to single pivot axis mounting formation 300 . The single pivot axis mounting formation 300 is attached to a second antenna bracket mounting formation 400 , and the second antenna bracket mounting formation 400 is attached to a panel antenna system 500 . In this exemplary configuration, the antenna system can be rotated, around the single pivot axis mounting formation 300 by at maximum 120° (i.e. −60° to 0° as shown in FIG. 4 b and 0° to +60° as shown in FIG. 4 c ) with respect to its home position α° HP. After completing the antenna system heading “home position” measurements in the direction of azimuth with respect to the grid or true north (absolute azimuth directionality), it can be seen from FIGS. 4 b and 4 c that the azimuth movement range of the antenna system 500 , either clockwise 1100 or counterclockwise 1200 , cannot satisfy the offset angle (α1° OFF) required to meet α° PP (defined by the radio planning and installation work orders)—i.e. α° HP+/−α1° OFF=α° PP. This is due to the fact that α° PP>α° HP, and that α° HP+(max clockwise antenna system movement range 1100 )<α° PP.
In order to address this problem, a reference point on the antenna structure can be introduced, according to the teachings of WO2011042226, such that the antenna system group “home position” is aligned with respect to this reference point, and the reference point is aligned to some heading in the horizon with respect to GTN. The reference point on the antenna structure will be referred to herein as ABS. In the exemplary first configuration as described with reference to FIG. 4 a , FIG. 4 b and FIG. 4 c , the antenna system azimuth “planned position” is achieved by rotating the first antenna bracket mounting formation 200 clockwise by α° PP−α° HP. In this way, antenna system alignment to “planned position”, as well as maximum movement range around the “planned position” for future re-adjustments, is achieved. For installation similar to the one described herein, the reference point ABS has been selected in order to match the antenna system α° PP. In a general case, and to cover complex configurations (i.e. number of antenna systems=n, number of pivot axiss per antenna system=m) a special method need to be employed such that any installation parameters can be satisfied.
Even for relatively simple installation scenarios (like the one described above), the definition of the antenna system group “home position” with respect to ABS is an important aspect that needs to be considered when defining the antenna system group “home position” on the antenna structure. In an exemplary configuration comprising a triple antenna system, dual pivot axis per antenna system antenna structure, as shown in plan view in FIG. 5 a , three antenna systems are aligned from their “home positions” α° HP 1 , α° HP 2 , α° HP 3 . Additionally, both antenna system alignment to the desired radio planning and installation work order azimuth directionalities in the “planned positions” α PP 1 , α° PP 2 , α PP 3 as well as maximum movement range for each antenna system with respect to the “planned positions” for future radio planning and installation work order azimuth re-adjustments must be achieved.
As shown in FIG. 5 a , the “home positions” of the antenna systems are arranged at 120° apart from each other, in such a way that the maximum movement range per antenna system attached on the antenna structure is the maximum possible (i.e. −60°≦α° HP≦+60°). This set up defines an antenna structure of three antenna systems with “home positions” α° HP 1 , α° HP 2 , α° HP 3 and a movement range R1°=R2°=R3°=120° for each antenna system respectively. Assuming that a reference point on the antenna structure (ABS) has not been selected and correlated with any antenna system “home position”, it may be considered that the three antenna systems are able to achieve any azimuth directionality defined by radio planning and installation work orders due to the fact that together they cover all 360° on the horizon on 120° equal slices. However, this is not possible as there are some combined antenna system directionalities that cannot be achieved. An example of such a case could be aligning the azimuth of two antenna systems to the same “planned position” (i.e. α° PP 1 =α PP 2 ).
In the exemplary configuration as shown in FIG. 5 a and FIG. 5 b , the antenna system azimuth movement range is defined as α° HP k min ≦α° HP k ≦α° HP k max for each antenna system k=1 . . . n, where α° HP k min =α° HP k −R°/2 and α° HP k max =α° HP k +R°/2 for maximum permissible antenna system movement range R° where R°=R1°=R2°=R3° for each antenna system respectively. This means that, when n=3, for each antenna system attached on the antenna structure, the first antenna system “home position” will be α° HP 1 =α°, the second antenna system “home position” will be α° HP 2 =α° HP 1 +R° and the third antenna system “home position” will be α° HP 3 =α° HP 1 +2R°. Therefore, all three antenna systems on the antenna structure are separated by an equal distance such that the movement range of each antenna system can be defined as follow:
α° HP 1 min =α° HP 1 −R°/ 2 and α° HP 1 max =α° HP 1 +R°/ 2 where α° HP 1 =α°
α° PP 1 =[α°−60 °≦α° HP 1 ≦α°+60°] Antenna System 1:
α° HP 2 min =α° HP 2 −R°/ 2 and α° HP 2 max =α° HP 2 +R°/ 2 where α° HP 2 =α° HP 1 +R°
α° PP 2 =[α°+ R°− 60 °≦α° HP 2 ≦α°+R°− 60°] Antenna System 2:
α° HP 3 min =α° HP 3 −R°/ 2 and α° HP 3 max =α° HP 3 +R°/ 2 where α° HP 3 =α° HP 1 +2 R°
α° PP 3 =[α°+2 R°− 60 °≦α° HP 3 ≦α°+2 R°+ 60°] Antenna System 3:
T correlating each antenna system α° HP 1 , α° HP 2 , α° HP 3 with a reference point ABS, we need to know the first antenna system α° HP 1 offset Θ° with respect to this reference point ABS. Assuming that the reference point ABS has an offset Θ°=α° with our first antenna system “home position” α° HP 1 (i.e. ABS+Θ°=ABS+α°=α° HP 1 ) then the antenna system “home position” for all antenna systems, with respect to ABS will be α° HP 1 =ABS+α°, α° HP 2 =ABS+α°+120°, α° HP 3 =ABS+α°+240°. The next step is to define the reference point ABS to the absolute azimuth heading in the horizon with respect to GTN. Several prior art solutions are currently available for such measurements. For example, US20090021447 and US20110225804 describe a device for the accurate measurement of the orientation of an antenna system in three directions, i.e. azimuth, tilt and roll which can be used for the purpose described herein.
By way of example, if we assume that the reference point ABS coincides with our first antenna system “home position” α° HP 1 (i.e. Θ°=0°) and ABS=0° with respect to GTN, the assigned ABS (i.e. ABS=0°) does not satisfy the orientation of two antenna systems to achieve the azimuth directionality defined by radio planning and installation work orders for α PP 1 =α° PP 2 =110°. This is because the first antenna system has movement range of 0° to 120° [−60°≦α° HP 1 ≦+60° ] (and therefore can be oriented at 110°) and the second antenna system has movement range of 120° to 240° [+60°≦α° HP 2 ≦+180° ] (and therefore cannot be oriented at) 110°. In order to address this problem, it is necessary to select the ABS heading with respect to GTN.
The reference position utilized in the present invention is derived by the following procedure, graphically illustrated in FIG. 6 . The parameters considered in the reference position computations involve the antenna system movement range, with respect to the “home position” on the antenna structure, the number of antenna systems, and the target horizontal (azimuth) directionality angles for each antenna system. Initially, the number n of the antenna systems attached to an antenna structure is obtained. In the mentioned example, the antenna structure reference point ABS lays at an angle equal to the first antenna system minimum directionality angle, with respect to the first antenna system “home position” on the antenna structure α° HP 1 . For each antenna system k=1 . . . n, with maximum permissible antenna system movement range R and target horizontal (azimuth) directionality angle α° PP k , an antenna structure reference position acceptance range extending from α° HP kmin to α° HP kmax may be computed by α° HP kmin =α° PP k −R×k and α° HP kmax =α° PP k −R×(k−1). For example, considering n=3 antenna systems with maximum permissible antenna system movement range R=120°, the corresponding temporary antenna structure reference position acceptance ranges are:
α° HP 1min =α° PP 1 −120 and α° HP 1max =α° PP 1 , i.e. A 1 temp =[α° PP 1 −120,α° PP 1 ]
α° HP 2min =α° PP 2 −240 and α° HP 2max =α° PP 2 −120, i.e. A 2 temp =[α° PP 2 −240 ,α° PP 2 −120]
α° HP 3min =α° PP 3 −360 and α° HP 3max =α° PP 3 −240, i.e. A 3 temp =[α° PP 3 −360 ,α° PP 3 −240].
Having calculated the temporary antenna structure reference position acceptance range for each antenna system k attached to an antenna structure, a new antenna structure reference position acceptance range is computed by intersecting the temporary antenna structure reference position acceptance ranges, as
A new =A 1 temp ∩A 2 temp ∩A 3 temp .
The optimum reference position value ABS, in the sense that it ensures maximum permissible antenna system movement range, needed for future azimuth re-adjustments, for either a single pivot axis or dual pivot axis antenna systems attached to the antenna systems, with respect to the installed horizontal (azimuth) directionality angles, is calculated by computing the new antenna structure reference position acceptance range mean value as:
ABS =( A new min +A new max )/2.
The antenna systems attached to an antenna structure are then aligned or pre-calibrated to the antenna structure reference point ABS. The parameters considered in the antenna system “home position” computations involve the antenna system movement range, with respect to the antenna system “home position” on the antenna structure and the number of antenna systems. In the same example, the antenna structure reference point ABS lays at an angle equal to the first antenna system minimum directionality angle, with respect to the first antenna system “home position” on the antenna structure. For each antenna system k=1 . . . n, with maximum permissible antenna system movement range R°, an antenna system “home position” on the antenna structure according to which the antenna system movement range is calibrated may be computed by α° HP k =0.5R×(2k−1). In a second example, the antenna structure reference point ABS lays at an offset angle θ° from the first antenna system minimum directionality angle, with respect to the first antenna system “home position” on the antenna structure. For each antenna system k=1 . . . n, with maximum permissible antenna system movement range R°, an antenna system “home position” on the antenna structure according to which the antenna system movement range is calibrated may be computed by α° HP k =θ+0.5R×(2k−1).
For n=3 antenna systems with maximum permissible antenna system movement range R°=120° attached to an antenna structure are aligned or pre-calibrated to the antenna structure reference point ABS at 60°, 180° and 300°. Otherwise stated, the antenna system “home positions” are thus aligned or pre-calibrated to the antenna structure reference point at 60°, 180°and 300°. As a further example, the n=6 antenna systems with maximum permissible antenna system movement range 60° attached to an antenna structure are aligned or pre-calibrated to the antenna structure reference point at 30°, 90°, 150°, 210°, 270° and 330°. Otherwise stated, the antenna system “home positions” are thus aligned or pre-calibrated to the antenna structure reference point ABS at 30°, 90°, 150°, 210°, 270° and 330°.
An alignment device such as the one described in US20110225804A1 may be fixedly attached to the antenna structure reference point to determine the absolute azimuth, tilt and roll antenna structure reference point directionality with respect to GTN and CGA. The use of an alignment device to undertake the antenna structure reference point alignment with respect to the reference position may result in a precise antenna system alignment with minimum inaccuracy (less than) ±1° with respect to the specified horizontal (azimuth) and vertical (tilt) directionality angles provided from the radio planning process and installation work order. A skilled reader will recognize that other means of absolute azimuth, tilt and roll directionality measurement may be utilized for the same purpose. Thus, the result is an absolute directionality positioning of the antenna structure reference point when an alignment device is attached thereto. Advantageously, the antenna structure reference point is arranged or otherwise positioned in accordance with the calculated reference position ABS.
In another exemplary implementation, the antenna structure reference point may be aligned, in accordance to the present invention, to a calculated reference position of ABS, following the process outlined in FIG. 6 , as such, the antenna structure reference point lays at an angle equal to the first antenna system minimum directionality angle, with respect to the first antenna system home position on the antenna structure. For each antenna system k=1 . . . n, with maximum permissible antenna system movement range R, an antenna system absolute home position on the horizon according to which the antenna system movement range is calibrated may be computed by α° HP k =ABS+0.5R×(2k−1). In another implementation, the antenna structure reference point lays at an offset angle θ from the first antenna system minimum directionality angle, with respect to the first antenna system home position on the antenna structure. For each antenna system k=1 . . . n, with maximum permissible antenna system movement range R, an antenna system absolute home position on the horizon according to which the antenna system movement range is calibrated may be computed by α° HP k =ABS+θ+0.5R×(2k−1).
The computations performed to calculate the antenna systems' first and/or second pivot axis offset with respect to the antenna systems home positions, in order to achieve the target horizontal (azimuth) directionality angles for each antenna system and the antenna system thereto attached are outlined in FIG. 6 . The parameters considered in the antenna systems' first and/or second pivot axis offset computations involve the antenna systems' absolute home position, the antenna systems' first and/or second pivot axis movement range with respect to the associated antenna system home position on the antenna structure and the target horizontal (azimuth) directionality angles for each antenna system. Generally, an antenna system absolute azimuth, tilt and roll directionality may be calculated by summing the antenna structure reference point directionality plus the known offset of the aligned or pre-calibrated antenna system azimuth, tilt and roll directionality with respect to the antenna structure reference point azimuth, tilt and roll directionality plus or minus the antenna systems' first and/or second pivot axis offset with respect to the antenna systems home positions.
In one embodiment of the present invention, the antenna structure reference point may be aligned, in accordance to the present invention, to a calculated reference position of ABS, following the process illustrated in FIG. 6 . The antenna structure reference point directionality may preferably be equal to the calculated reference position to so that an even or about even distribution of the allowable antenna system movement range in both clockwise and counterclockwise directions with respect to the corresponding antenna system target horizontal (azimuth) directionality angle may be attained.
In one example mode of implementation, the antenna structure reference point lays at an angle equal to the first antenna system minimum directionality angle, with respect to the first antenna system home position on the antenna structure. For each antenna system k=1 . . . n, with maximum permissible antenna system movement range R, an antenna system absolute home position on the horizon according to which the antenna system movement range is calibrated may be computed by α° HP k =ABS+0.5R×(2k−1). For each antenna system k=1 . . . n, with maximum permissible antenna system movement range R, having a first pivot axis with maximum permissible movement range R 1 and/or a second pivot axis with maximum permissible movement range R 2 such that R=R 1 +R 2 , the antenna system absolute azimuth directionality may be computed by α° PP k =α° HP k +OA 1 +OA 2 , where OA 1 , OA 2 are the first pivot axis and/or a second pivot axis offset angles with respect to the antenna system home positions.
In an exemplary embodiment of the present invention, the n=3 antenna systems with maximum permissible antenna system movement range 120° attached to an antenna structure are aligned or pre-calibrated to the antenna structure reference point at 60°, 180° and 300. Given the target directionality angles α° PP 1 =110°, α° PP 2 =110° and α° PP 3 =320°, the antenna structure reference point may be aligned, in accordance to the present invention, to a calculated reference position ABS of 350°. For each antenna system k=1, 2, 3 with maximum permissible antenna system movement range 120°, an antenna bracket absolute home position on the horizon according to which the antenna bracket movement range is calibrated may be computed by
α° HP 1 =350°+0.5×120×(2−1)=50°.
α° HP 2 =350°+0.5×120×(4−1)=170°.
α° HP 3 =350°+0.5×120×(6−1)=290°.
It can be seen that ABS should always calculated according to workflow of FIG. 6 so as to satisfy radio planning and installation work orders in order to achieve multi antenna system (i.e. k=n) azimuth alignment to “planned positions” and also maximum movement range around the “planned position” for future azimuth re-adjustments. The ABS should be located on the reference point system attached on the antenna structure for alignment purposes. As described, the proposed method for enabling the accurate alignment and repeatable alignment with accuracy of communication antenna systems comprises ten steps as follows:
(10) Antenna system group alignment on an antenna structure CVA
(11) Reference point system alignment on an antenna structure CVA
(12) Antenna system imaging and surveying on reference point system
(13) Measurement of reference point system directionality of azimuth, tilt and roll with respect to GTN and CGA respectively on a selected reference point ABS of known offset Θ° with respect to the first antenna system image on the reference point system
(14) Calculation of the antenna systems on the reference point system with respect to the selected reference point ABS measured azimuth, tilt and roll
(15) Assignment of antenna systems azimuth, tilt and roll directionalities with respect to GTN and CGA at “home position”
(16) Re-adjustment of antenna system azimuth heading from “home position” to “planned position” according to radio planning and installation work orders
(17) Computation of “new” tilt and roll directionalities after azimuth re-adjustment with respect to the “home position” directionalities measured on the reference point system
(18) Assignment of antenna system tilt and roll directionalities with respect to CGA at “home position” on re-adjusted azimuth heading with respect to GTN on “planned position”
(19) Re-adjustment of antenna system tilt and roll directionality from “home position” to “planned position” according to radio planning and installation work orders
In order to apply the method of FIG. 6 and also achieve accurate and repeatable with accuracy alignment of communication antenna systems without the need for a technician, rigger or climber to come in direct contact with the antenna system itself, an apparatus is proposed herein that is attached on an antenna bracket (1). The apparatus is capable of remote azimuth re-adjustment of an antenna system (2), remote tilt re-adjustment of an antenna system (3), and can receive the reference point system measurements performed for azimuth tilt and roll headings in “home position” (4). The apparatus is also capable to compute the installation imperfection offset introduced on the antenna system tilt and roll headings in “home position” with respect to the ideal (i.e. tilt=0° and roll=0°) (5), calculate the new antenna system tilt and roll headings in “home position” for any azimuth heading of the antenna system, the “planned position”, and communicate with a remote user in order to perform all above actions (7).
FIG. 10 shows, as an exemplary configuration, a perspective, cut-away view of an apparatus according to the present invention. The apparatus includes a metal housing 800 having an upper wall 801 , a lower wall 802 , a removable front wall (not shown), a rear wall 803 and opposite side walls 804 and 805 . The apparatus is appropriately attached on an antenna bracket so as to be uniquely positioned at the bottom of the antenna bracket pivot axis 300 . This position facilitates field maintenance by engagement means which include four guide pins 320 for accurate positioning on the antenna bracket, such that when positioning the apparatus on the antenna bracket, the apparatus roll and tilt axis (X and Y respectively) are perpendicular to the antenna bracket pivot axis 300 , thus ensuring the respective antenna bracket roll and tilt axis to be parallel to the apparatus roll and tilt axis. In this way, the apparatus is appropriately positioned on the antenna bracket to ensure it is perpendicular to the antenna system azimuth plane and parallel to the antenna system tilt and roll planes. Therefore, by the unique positioning of the apparatus on the antenna bracket, we may easily assign the azimuth, tilt and roll angles of the antenna system on the apparatus and vice versa. A prerequisite for such assignment is that the antenna system has been assembled on the antenna structure according to the method described above.
Referring now to FIG. 7 , a drive unit 850 , including a stepper motor 851 and a gearbox 852 , allows remote control of the antenna bracket horizontal (azimuth) direction. The gearbox 852 is a minimum backlash high gear ratio planetary gear box that translates high speed, low torque motor rotation to lower speed, higher torque rotation of the drive gear turned by the stepper motor 851 . A position detector (not shown), typically a potentiometer or an optical encoder which is driven by the pivot axis coupling unit 860 , is located inside the stepper motor 851 . Advantageously, an electrical potentiometer or an optical encoder to perform the measurements in the horizontal direction (azimuth) are both immune to external magnetic disturbances, such as the magnetic disturbances generated by the antenna system, antenna bracket and the antenna structure. The measurements performed by such devices are therefore highly accurate.
Azimuth adjustment is normally performed mechanically by moving the antenna around the antenna structure but could alternatively be performed electrically. Tilt re-adjustment is preferably performed by means of mechanical phase shifting of the dipoles feeding lines so as to adjust the direction of the radiation pattern in the tilt plane. Consequently, no further degrees of freedom, other than the electrical tilt options offered from the antenna system, will be described. Tilt adjustment may also be achieved by mechanical adjustment of the antenna. Similarly, roll adjustment may be performed mechanically or electrically. Often, however, roll adjustment is not required but measurement of the change to roll is still useful as it may affect future adjustments of azimuth or tilt. A printed circuit board (PCB) that serves the purpose of apparatus controller 900 is appropriately configured so as to perform all necessary Remote Electrical Tilt (RET) and Remote Azimuth Steering (RAS) apparatus operations by a sequence of steps as those are shown in FIG. 8 and FIG. 9 respectively:
Advantageously, the use of a PCB controller to compute all necessary azimuth, tilt and roll headings for the antenna system, as well as providing the means of remotely communicating with a remote user, enables the apparatus to interface to third party devices (such as the antenna system RET kit and other antenna line devices) and also does not require use of on-site inclinometer sensors for tilt an roll measurements.
In an alternative configuration as shown in FIG. 10 , one may include an inclinometer system ( 870 ) inside the apparatus metal housing ( 800 ), such that the inclinometer measurement roll and tilt axis (X and Y respectively) to be parallel to the apparatus roll and tilt axes (X and Y respectively) by installing a angle metal plate ( 871 ) perpendicular to rear metal wall ( 803 ) and parallel to the upper metal wall ( 801 ). The previous step ensures that the apparatus roll and tilt axes (X and Y respectively) are perpendicular to the antenna bracket pivot axis ( 300 ) while the respective antenna bracket roll and tilt axes (X and Y respectively) are parallel to the apparatus roll and tilt axes (X and Y respectively) thus parallel to inclinometer measurement roll and tilt axis (X and Y respectively). In this way it can be avoided the measurement of roll and tilt in the reference point system, providing further flexibility on the antenna system alignment method described herein at the cost of introducing an inclinometer system ( 870 ) inside the apparatus. In an alternative configuration as shown in FIG. 11 , one may apply the teachings of the present invention with the use of two apparatus (one apparatus per pivot axe) on a dual pivot axis antenna system group.
Further aspects of the invention:
1. Apparatus for positioning an antenna pivotally attached about at a first pivot axis and a second pivot axis to a structure, comprising
at least a first motor system and a second motor system, wherein the first motor system is configured to effect movement of the antenna about the first pivot axis and the second motor system is configured to effect movement of the antenna about the second pivot axis, and
a control unit configured to control operation of each motor system, wherein the control unit is configured to calculate the extent of movement required by each motor system in order to produce a desired change in antenna position.
2. The apparatus of 1, wherein the first motor system comprises one or more measurement devices for measuring the extent of movement of the antenna sector about the first pivot axis and the second motor system comprises one or more measurement devices for measuring the extent of movement of the antenna sector about the second pivot axis, and preferably wherein measurements by each of the measurement devices are output to the control unit.
3. The apparatus of 2, wherein the control unit is configured to control operation of each motor system using measurements from the measurement devices.
4. The apparatus of any of 1 to 3, wherein the control unit is configured to store calibrated position data of the antenna sector.
5. The apparatus of 4, wherein the control unit is configured to control operation of each of the motor systems in order to position the antenna to a desired azimuth based on measurements from the measurement devices and the calibrated position data.
6. Apparatus for positioning an antenna pivotally attached about at a first pivot axis and a second pivot axis to a structure, comprising
at least a first motor system and a second motor system, wherein the first motor system is configured to effect movement of the antenna about the first pivot axis and the second motor system is configured to effect movement of the antenna about the second pivot axis, and wherein the first motor system comprises one or more measurement devices for measuring the extent of movement of the antenna sector about the first pivot axis and the second motor system comprises one or more measurement devices for measuring the extent of movement of the antenna sector about the second pivot axis, and
a data storage device, wherein the data storage device is configured to store measurements from each of the measurement devices.
7. The apparatus of 6, wherein the storage device is further configured to store calibrated position data of the antenna.
8. The apparatus of 7, wherein the first motor system is arranged to effect movement of the antenna about the first pivot axis and the second motor system is arranged to effect movement of the antenna about the second pivot axis based on a calculation of the current position of the antenna from calibrated position data of the antenna and measurements from each of the measurement devices stored in the storage device.
9. The apparatus of 6 or 7, further comprising a control unit in communication with the storage device, wherein the control unit is configured to control operation of each of the motor systems.
10. The apparatus of 9, wherein the control unit is configured to determine the current position of the antenna sector using calibrated position data and outputs from each of the measurement devices.
11. The apparatus of 10, wherein the storage device is further configured to store the current position of the antenna.
12. The apparatus of any of 6 to 11, further comprising user input means.
13. The apparatus of 6, wherein the control unit is configured to calculate a desired azimuth for the antenna sector using data input via the user input means.
14. The apparatus of 13, wherein the control unit is configured to control operation of the motor systems in order to position the antenna to the desired azimuth.
15. Apparatus for determining the alignment accuracy of an antenna mounted on an antenna sector having two pivoting axes, comprising:
at least two motor systems, wherein a first motor system comprises one or more measurement devices for measuring the extent of movement of the antenna sector about a first pivot axis and a second motor system comprises one or more measurement devices for measuring the extent of movement of the antenna sector about a second pivot axis, and wherein a value of a measurement by each measurement device has an associated predefined error value, and wherein
the first motor system is arranged to effect movement about the first pivot axis and the second motor system is arranged to effect movement about the second pivot axis.
16. The apparatus of 15, further comprising a control unit, wherein the control unit is in communication with each of the motor systems.
17. The apparatus of 15 or 16, wherein the control unit is arranged to store calibrated position data of the antenna sector.
18. The apparatus of 17, wherein the control unit is configured to determine the position of the antenna using measurements from each of the measurement devices and calibrated position data.
19. The apparatus of 18, wherein the control unit is further configured to calculate the total error of the value of the determined position of an antenna in each of the X, Y and Z directions.
20. The apparatus of any of 6 to 19, wherein the measurement devices include at an optical encoder.
21. The apparatus 20, wherein the measurement devices further include a tilt sensor, a roll sensor, a motion calibrator and a potentiometer.
22. The apparatus of any of 6 to 21, wherein the control unit is further configured to determine the accuracy of the alignment of the antenna sector.
23. A motor system for effecting movement of an antenna sector about a pivot axis, comprising one or more measurement devices for measuring the extent of movement of the antenna sector about the pivot axis, wherein operation of the motor system is based on the measurements from each of the one or more measurement devices.
24. The motor system of 23, wherein the one or more measurement devices include an optical encoder, a tilt sensor, a roll sensor, a motion calibrator and a potentiometer.
25. The motor system of 23 or 24, wherein the motor system is in communication with a control unit, and wherein the control unit is arranged to control operation of the motor system using measurements from the measurement devices.
26. The motor system of 23 to 25, wherein a measurement by each of the one or more measurement device has a predefined associated error value.
27. A control unit for controlling movement of an antenna structure, comprising computer program code for executing the method of 1.
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A method of adjusting at least one cellular communications antenna mounted on an antenna structure, wherein the antenna, and/or direction of the radiation pattern of the antenna, is movable relative to the antenna structure, the method comprising the steps: determining or retrieving current position values of the antenna, and/or direction of the radiation pattern of the antenna, in first, second and third dimensions; receiving a desired position value for the antenna, and/or direction of the radiation pattern of the antenna, in the first dimension relating to a desired position of the antenna; determining a new position value for the antenna, and/or direction of the radiation pattern, of the antenna in the second dimension based on required movement of the antenna, and/or direction of the radiation pattern of the antenna, relative to the antenna structure to reach the desired position value in the first dimension; determining a new position value for the antenna, and/or direction of the radiation pattern of the antenna, in the third dimension based on required movement of the antenna relative to the antenna structure to reach the desired position value in the first dimension; calculating the difference between the current and new position values in the second dimension; calculating the difference between the current and new position values in the third dimension; adjusting the position of the antenna, and/or direction of the radiation pattern of the antenna, towards the desired position by moving the antenna, and/or direction of the radiation pattern of the antenna, relative to the antenna structure based at least in part on the calculated difference of first and second positions in at least the second dimension.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a shoe fastener which can be actuated via a rotary element with a pulley pivotally mounted in a bearing element coaxially with respect to a central axis of the rotary element for winding at least one cable-like tension element, a reducing gear between the rotary element and the pulley in the form of an eccentric drive in which an external unwinding gear is pivotally mounted in a housing of the shoe closure and which is securable in each of several angular positions.
Such a shoe fastener, with an eccentric gear mechanism, is described in my German patent DE 42 40 916 C1. The outer unwinding toothed wheel is pivoted there in the housing and can be fixed in position by one or more grooves on the circumference.
2. Description of Related Art
Other shoe fasteners are also known, for example from EP 255 869 A2, in which the rope pulley is pivoted in a housing on a stationary steering pivot pin and is driven like a Geneva movement or a planetary gear. The top side of the housing cover is provided with an annular gear which, together with a catch that can be actuated by the turning component, forms a catch device that catches in the closing direction. The turning component has a driving peg that engages in an arc-shaped recess in a washer. The recess extends over a small angle sector so that the turning component is freely movable, relative to the washer, by a small angle of rotation of, for example, 30°.
The catch is elastically prestressed on the washer so that a projecting tooth engages in the annular gear and another projecting tooth located on the opposite side engages in another arc-shaped steering recess of the turning component. The steering recess is cut free on one end so that, when the turning component turns in the closing direction, the engaging projecting tooth remains freely movable. When the mining component turns in the closing direction, and after the driving peg strikes within an allocated recess, the washer is also moved. Thus the catch is moved by the annular gear and in doing so catches, by slanted sides, from one tooth to the next.
When the turning component turns in the opening direction, it turns, relative to the washer, according to the clearance angle defined by the recess. In doing so, a ramp-like, rising control surface present on the other end of the steering recess presses the catch, by the allocated projecting tooth, and the catch thus is moved out of the radius of action of the annular gear. Thus the possibility of locking is eliminated and the turning knob can be turned in the opening direction and the rope pulley can be turned, by the gear mechanism, in the unwinding direction. A quick opening of the shoe fastener is thus not possible, despite the relatively expensive construction of the shoe fastener.
Further, shoe fasteners with a turning component are known that have a planetary gear. With these fasteners, a quick disengagement is possible in that, by pressure on the center of the turning knob in the direction of the central axis, the gear mechanism is decoupled from the rope wheel, so that the rope wheel can be freely turned.
SUMMARY OF THE INVENTION
In contrast, with this invention the object to be achieved is to configure a shoe fastener of the above-mentioned type so that a quick disengagement of the shoe fastener and the opening of the shoe with a single actuation component can be performed almost simultaneously.
This object is achieved by the following features:
(a) the unwinding gear is formed of a disk having a grooved outer catch rim;
(b) a catch element is supported outside of the action range of the unwinding gear disk and is deflectable transversely with respect to the central axis;
(c) the catch element is elastically pretensioned by a tension element such that a catch component of the catch element, which points towards the outer catch rim, elastically latches into a groove of the outer catch rim;
(d) the catch element has at least one release arm;
(e) the release arm is coupled to the tension element and can be actuated from the outside for disengaging the catch component from the catch rim;
(f) there is a shoe closure on a shoe part which can move in an opening direction when the shoe is opened; and
(g) the shoe closure can be moved together with the shoe part in the shoe opening direction via the tension element.
In contrast to known quick releases by pressure on a central part of the rotary element, in the quick release design according to the invention the shoe closure can be pulled via the tension element in the shoe opening direction at the same time with its base.
From EP-A-0 297 342 A2 a shoe closure is known which can be actuated by a rotary member, in which a catch element is supported to deflect transversely to the central axis. The catch element can be swivelled in the unlock direction by a lever swivel mounted on the closure via a push button which projects laterally from the closure and which is provided on the lever. However as the drive for the pulley there is a spur gear there which is not self-locking for the multiplication used there. The catch element is therefore necessary in order to be able to maintain a tensioned state when the shoe is closed. For this reason the catch element interacts with ratchet teeth which is present on the bottom of the pulley, so that the pulley can be turned in the tension direction, but not in the release direction. For quick release the catch lever can be swivelled out of a area of the ratchet teeth via the push button, by which the spur gear can then turn freely. To open the shoe therefore both the push button must be pressed and at the same time the shoe opened for example by pulling on the tongue or on the top material. When this known ratchet interlock is used on a pulley driven by a cam drive releasing the catch element would have no effect at all, since the cam drive is self-locking even at a small multiplication ratio. Quick release must therefore be done differently when using a cam drive. One advantageous solution of this problem is achieved by this invention.
Other advantageous details of the invention are given in the subclaims and are detailed below using the embodiments shown in the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross section through a shoe closure with a cam drive as the reducing gear in the locked state;
FIG. 2 shows the same shoe closure in the unlocked state;
FIGS. 3 and 4 show two different embodiments of the catch element;
FIG. 5 shows the end section of a pull strap;
FIG. 6 shows an individual view of the spring arrangement;
FIG. 7 shows a cross section as in FIG. 1 but with another embodiment of a catch means;
FIG. 8 shows an enlarged view of the section of the shoe closure of FIG. 7 which is located in the circle.
FIG. 9 shows a cross section through a shoe fastener with an eccentric gear mechanism in the engaged state and with another possibility of the drawstring arrangement,
FIG. 10 shows a top view of the shoe fastener according to FIG. 9, in section, in the engaged state, and the engagement is visible by leaving out the gear parts,
FIG. 11 shows a cross section similar to that of FIG. 9, but in the disengaged state, and
FIG. 12 shows a top view of the shoe fastener according to FIGS. 9 and 10 each in the disengaged state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The shoe fastener according to the invention has, according to FIGS. 1 and 2, a housing part 1 that has a circular recess 2 to receive a rope pulley 3 and ropelike tightening component(s) 3a. The insertion of ropelike tightening component(s) 3a into rope pulley 3 is performed by guide mechanisms, known in the art, in housing part 1. Rope pulley 3 has a centered hole 4 through which a bearing neck 5 of an axle unit 6 engages and ends in a bearing hole 7 of bottom 8 of housing part 1. The axle of bearing neck 5 simultaneously forms central axis 9 of the shoe fastener.
An eccentric drive pulley 10 lies on rope pulley 3. The former has a central bearing hole 11 with which it is pivoted on an eccentric drive pin 12, placed eccentrically to central axis 9, of axle unit 6. In each case there lies, on a circle that is concentric to central axis 13 of eccentric drive pin 12, center point 15 of several, six here in the embodiment, circle sectors 16, in each of which one coupling pin 17 of rope pulley 3 engages. The angular position of circle sectors 16 corresponds to those of coupling pins 17. Preferably, circle sectors 16 are each mutually offset by the same angle, by 60° in the embodiment. Basically, a single circle sector 16, operationally connected to only one coupling pin 17, would also be sufficient.
By turning axle unit 6 around central axis 9, center axis 13 of eccentric drive pin 12 describes a concentric orbit to central axis 9. Center points 19 of coupling pins 17 lie on a center circle that is concentric to central axis 9.
The outer contour of eccentric drive pulley 10 has teeth 21 that can roll on an inner contour, made as counterteeth 22, of a collar 23, which projects downward on one side, of a pulley 24 that covers eccentric drive pulley 10 and is made as a winding toothed wheel. Pulley 24 has a central hole 25 with which the pulley is pivoted on axle unit 6, concentric to central axis 9. Pulley 24 further has an outer catch rim 26 made as an outer toothed rim, in which a catch component 40 in the form of a catch finger of a catch element 42, for example a catch bar or another suitable catch element, pivoted on a pivot pin 41, engages. Preferably, a spring with two, preferably tangentially projecting spring parts 44, 45 and made as a coil spring 43 is put on same pivot pin 41. One projecting spring part 45 presses, with pretensioning, against catch component 40 and presses it into a groove of outer catch rim 26 and thus can lock the winding toothed wheel or pulley 24 in all the angular positions predetermined by the teeth.
Attached to a freely projecting disengagement arm 46 is a pulling element 47 that can be actuated from the outside and by which catch element 42 can be pulled against the spring force of spring 43 into the disengagement on freely projecting release arm 46 tension element 47 is attached which can be actuated from the outside and via which catch element 42 can be pulled in the release direction against the spring force of spring 43.
Attachment of tension element 47 to catch element 42 can take place via hole 48 which is provided in release arm 46 and in which tension element 47 which consists for example of spring steel wire is suspended with a bent hook or is attached in some other way.
According to FIGS. 2, 4 and 5 tension element 47 can be formed at least on inner end 49 as a pull strip. For its attachment on catch element 42 it has recess or opening 50 with which it is suspended in a hook or at least in one retaining finger 51 or in two retaining fingers 51, 52 of release arm 46. Opening 50 is advantageously made as a slot which runs transversely to the tension direction in the ready-to-operate state. Its length and width are such that tension element 47 in a direction transverse to the pull direction is inserted via retaining finger(s) 51, 52 and the position is fixed after swivelling into the tension direction.
Disk 24 has on the side opposite collar 23 another collar which projects upward. By means of its outline the latter forms catch rim 28 against which catch spring 30 rests in an elastic and locking manner. Catch spring 30 is attached for its part in a suitable manner to rotary element 33 which overlaps disk 24. Rotary element 33 is connected to axis unit 6 or forms a structural unit with it. Rotary element 33 is provided with a preferably elastic cover cap 35 which preferably coupled, for example by connecting pegs 54, to turning component 33.
The shoe fastener can be attached to an instep covering 55, for example to an inner tongue of a shoe or to a tongue covering the shoe from the outside or to a holding part 56, attached to the latter tongue, for the shoe fastener.
The shoe fastener works in the following way:
The shoe fastener is in the locked position represented in FIG. 1 in which tightening element 3a can be still further pulled.
When covering cap 35 is turned, turning component 33 and, with it, axle unit 6, are turned by connecting pegs 54 in the tightening direction, for example clockwise.
Since pulley 24 is secured against twisting by catch component 40, it remains in the fixed position. By eccentric drive pin 12, eccentric drive pulley 10 is also moved and rolls with its teeth 21 on counterteeth 22 with reduced speed.
When eccentric drive pulley 10 is turned, rope pulley 3 is also turned by coupling pins 17, and circle sectors 16 move in a circle around coupling pins 17. In doing so, tightening element 3a is wound on rope pulley 3.
For quick disengagement, when pulling element 47 is pulled, catch element 42 is pivoted into the disengagement direction. In doing so, catch component 40 becomes disengaged from outer catch rim 26. In this way, pulley 24 can be freely turned in housing part 1 and, with it, rope pulley 3. The eccentric gear mechanism remains here in the locked position, so that all driving parts also turn.
Simultaneously, when pulling element 47 is pulled, the entire shoe fastener and, with it, its support, on which it is attached, i.e., the tongue or instep cover 55 of the shoe, is raised in the direction of arrow 57 and simultaneously thus the shoe is opened.
The disengagement position of catch component 40 is represented in FIG. 2, and, as catch element 42, one with suspending fingers 51 and 52 according to FIG. 4 is used, while in FIG. 1 a catch element 42 with a hole 48 according to FIG. 3 is represented.
After releasing pulling element 47, catch component 40 engages in a toothed groove of outer catch rim 26. Thus pulley 24 is again secured against twisting and the closing procedure can again be performed.
In the additional embodiment of this invention represented in FIGS. 7 and 8, the catch element is made as a catch spring 60, for example made of an elastic wire or strip stock made of steel, special steel, spring bronze, elastically springy plastic, or the like. Catch spring 60 is mounted on one side, for example under bottom 8 of the shoe fastener, or attached there in another way. Catch spring 60 engages, with its end section 61 made as hook-shaped catch component 40', from underneath around edge 62 of outer catch rim 26 and engages, with its own pretensioning, from above in the groove of the teeth of outer catch rim 26.
Pulling element 47 attached on the shoe, for example on the tongue, on bottom 8, or on catch spring 60, runs, at least in end section 61, under catch spring 60. When pulling element 47 is pulled in the direction of arrow 63, catch spring 60 or its end section 61 is raised upward because of play 64 present there and thus catch component 40' is disengaged from outer catch rim 26. Thus the quick disengagement of the shoe fastener and the opening of the shoe with a short pull on pulling element 47 is made possible.
After releasing pulling element 47, catch component 40' automatically catches in one of the grooves of outer catch rim 26 and the shoe can again be closed.
In the embodiment represented in FIGS. 9 to 12, drawstring 47 that can be actuated from the outside also engages in freely projecting disengagement ann 46 of catch element 42. In doing so, catch element 42 can be deflected crosswise to central axis 9 in such a way that its pivot pin 41 is placed running parallel to central axis 9. In this way, a flat construction of the central turning fastener is possible. Pulling element 47 is guided upward here on the shoe closure, on the side facing away from the shoe tip, out of the shoe fastener, and is made there for example as a looped handle. From there, drawstring 47 runs directly under housing 1 or in a special guide mechanism or in a guide channel of it, forward toward the shoe tip and there is wound by about 180° around disengagement arm 46 and then attached to the fastener or to a shoe part. After winding around disengagement arm 46, drawstring 47 can be wound by about 180° forward around a fastening part or around a shoe part and be attached on the shoe in the area of the shoe tip or of the tongue base, on the tongue or on an instep part, as shown in dashed lines in FIG. 11.
The way in which this shoe fastener works is essentially the same as was already explained based on the above-described embodiment.
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A shoe fastener with a rotary actuating element (35) that has a pulley (3) coupled thereto via a self-locking reduction gear which is in the form of an eccentric drive (10, 12). An unwinding gear is pivotally mounted in a housing (1) of the fastener and is formed of a disk (24) having a grooved outer catch rim (26). The unwinding gear can be fixed in any of several angular positions via a catch element (42) which can be released via a tension element (47) which, at the same time, can be used to pull open the shoe by lifting of a tongue or instep cover (55) of the shoe upon which the fastener is mounted.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention generally relates to a bicycle control device for shifting gears to change the speed of the bicycle. More specifically, the present invention in a preferred embodiment relates to a bicycle control device that includes both braking and/or speed changing functions.
[0003] 2. Background Information
[0004] Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle as well as the frame of the bicycle. Control devices for braking and/or shifting have been extensively redesigned in recent years.
[0005] In the past, brake levers and shifting devices were separate devices that were attached to the handlebar and/or frame of the bicycle. More recently, control devices have been developed the combine both the braking and shifting functions into a single unit. Examples of such control devices of this type are disclosed in the following U.S. Pat. Nos. 4,241,878; 5,257,683; 5,400,675; and 6,073,730. For effecting braking and speed change, some of these known control devices have a brake lever that also acts as a shift lever that winds a takeup element and a release lever located behind a brake/shift lever. While other known control devices have a shift lever that winds a takeup element located behind a brake lever and a release lever that is located laterally of the brake lever. Thus, the rider can carry out braking and speed change operations without the rider changing from one lever to another and without the possibility of rider injuring a finger. In particular, these control devices have a support member with a mounting portion configured to be coupled to the handlebar of the bicycle and a control lever that is pivotally coupled to the support member to move between a rest position and a shifting position about a shift pivot axis.
[0006] However, the control devices illustrated in these patents have a large angle between the shift pivot axis and the operating portion of the shift lever used to wind the shift cable. This arrangement results in the rider having to push the shift lever along a path that can be difficult for some riders. Likewise, the release levers of the control devices illustrated in these patents are not arranged in the most advantageous position for the rider to operate. Thus, the release lever of the control devices illustrated in these patents can be difficult for some riders to operate.
[0007] In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved control device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
SUMMARY OF THE INVENTION
[0008] One object of the present invention is to provide a control device that is easy to shift.
[0009] Another object of the present invention is to provide a compact and inexpensive bicycle control device that allows the rider to carry out braking and speed change operations without difficulty.
[0010] The foregoing objects can basically be attained by providing a bicycle control device comprising a support member, a cable winding mechanism, and a control lever. The support member has a mounting portion configured and arranged to be coupled to a bicycle handlebar and a distal end longitudinally spaced from the mounting portion. The cable winding mechanism is coupled to the support member, and has a cable attachment point. The control lever is operatively coupled to the cable winding mechanism. The control lever includes an attachment end portion and a shift operating portion extending outwardly from the distal end of the support member. The attachment end portion of the control lever is pivotally coupled to the support member to move between a rest position and a shifting position about a shift pivot axis that extends longitudinally between the mounting portion and the distal end. The shift operating portion of the control lever is configured and arranged to be disposed along a line that is angled relative to the shift pivot axis by approximately an angle between forty-five degrees and fifty-five degrees at the rest position and that passes through the attachment end portion at the shift pivot axis.
[0011] The foregoing objects can basically be attained by providing a bicycle control device comprising a support member, a cable winding mechanism, and a brake/shift lever. The support member has a mounting portion configured and arranged to be coupled to a bicycle handlebar. The cable winding mechanism is coupled to the support member, and has a cable attachment point. The brake/shift lever is operatively coupled to the cable winding mechanism. The brake/shift lever includes an attachment end portion and a brake/shift operating portion extending outwardly from the support member. The attachment end portion of the brake/shift lever is pivotally coupled to the support member about a shift pivot axis to move between a rest position and a shifting position. The attachment end portion of the brake/shift lever further is pivotally coupled relative to the support member about a brake pivot axis that is angled relative to the shift pivot axis. The shift operating portion of the brake/shift lever is configured and arranged to be disposed along a line that is angled relative to the shift pivot axis by approximately an angle between forty-five degrees and fifty-five degrees at the rest position and that passes through the attachment end portion at the shift pivot axis.
[0012] The foregoing objects can basically be attained by providing a bicycle control device comprising a support member, a cable winding mechanism, and a control lever. The support member has a mounting portion configured and arranged to be coupled to a bicycle handlebar and a distal end longitudinally spaced from the mounting portion. The cable winding mechanism is coupled to the support member, and having a cable attachment point. The control lever is operatively coupled to the cable winding mechanism. The control lever includes an attachment end portion and a shift operating portion extending outwardly from the distal end of the support member. The attachment end portion of the control lever is pivotally coupled to the support member to move between a rest position and a shifting position about a shift pivot axis that extends longitudinally between the mounting portion and the distal end. The mounting portion has a clamping plane extending perpendicularly from the bicycle handlebar to intersect with the shift pivot axis at an intersection point to form an acute angle as measured upwardly from the clamping plane and on a forward side of the shift pivot axis that away from the mounting portion.
[0013] The above objects are preferably achieved, according to the present invention, by a control device for a bicycle having a brake mechanism and a change speed change mechanism, comprising a brake lever assembly mounted on a handlebar for controlling the brake mechanism, wherein the speed change mechanism is controllable by movement of at least a portion of the brake lever assembly.
[0014] These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Referring now to the attached drawings which form a part of this original disclosure:
[0016] [0016]FIG. 1 is a side elevational view of a bicycle equipped with a pair of control devices (only one shown) in accordance with one embodiment of the present invention;
[0017] [0017]FIG. 2 is a side elevational view of the handlebar and the right hand side control device illustrated in FIG. 1 in accordance with the present invention;
[0018] [0018]FIG. 3 is a diagrammatic perspective view of the right hand side control device illustrated in FIGS. 1 and 2 in accordance with the present invention;
[0019] [0019]FIG. 4 is a front elevational view of the right hand side control device illustrated in FIGS. 1 - 3 in accordance with the present invention;
[0020] [0020]FIG. 5 is a partially exploded perspective view of the right hand side control device illustrated in FIGS. 1 - 4 in accordance with the present invention;
[0021] [0021]FIG. 6 is an enlarged side elevational of the right hand side control device illustrated in FIGS. 1 - 5 with a portion shown in cross section;
[0022] [0022]FIG. 7 is a partial cross sectional view of a portion of the right hand side control device illustrated in FIGS. 1 - 6 ;
[0023] [0023]FIG. 8 is a partial cross sectional view of a portion of the right hand side control device illustrated in FIGS. 1 - 6 ; and
[0024] [0024]FIG. 9 is a rear elevational view of the portion of the right hand side control device illustrated in FIG. 7 with portions broken away for purposes of illustration
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Selected embodiments of the present invention will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0026] Referring initially to FIG. 1, a bicycle 10 is illustrated with a pair of control devices 12 (only one shown in FIG. 1) mounted in a bicycle handlebar 13 in accordance with one embodiment of the present invention. The right hand side control device 12 is operatively coupled to a rear derailleur 14 via a shift cable 14 a and a rear braking device 15 via a brake cable 15 a , while the left hand side control device 12 is operatively coupled to a front derailleur 17 via a shift cable 17 a and a front braking device 18 via a brake cable 18 a . The right and left hand side control devices 12 are essentially identical in construction and operation, except that that are mirror images and the number of shift positions are different. Thus, only one of the control devices 12 will be discussed and illustrated herein. Each control device 12 is also preferably provided with an electronic shifting unit 18 with a pair of shift buttons that are operatively coupled to a cycle computer, preferably in accordance with U.S. Pat. No. 6,073,730 (assigned to Shimano, Inc.) and U.S. Pat. No. 6,212,078 (assigned to Shimano, Inc.).
[0027] As used herein to describe the control device 12 , the following directional terms “forward, rearward, above, downward, vertical, horizontal, below and transverse” as well as any other similar directional terms refer to those directions of a bicycle equipped with the present invention. Accordingly, these terms, as utilized to describe the present invention should be interpreted relative to a bicycle equipped with the control device 12 of the present invention.
[0028] Since these most of the parts of the bicycle 10 are well known in the art, the parts of the bicycle 10 will not be discussed or illustrated in detail herein, except for the parts relating to the control devices 12 of the present invention. Moreover, various conventional bicycle parts such as brakes, derailleurs, additional sprocket, etc., which are not illustrated and/or discussed in detail herein, can be used in conjunction with the present invention.
[0029] As best seen in FIG. 5, the bicycle control device 12 basically comprises a support member or bracket 21 and a braking/shifting mechanism 22 . The support member 21 is configured and arranged to be fixedly coupled to the bicycle handlebar 13 . The braking/shifting mechanism 22 is movably mounted to the support member 21 . The braking/shifting mechanism 22 basically operates in the same manner as described in U.S. Pat. No. 6,212,078 (assigned to Shimano, Inc.). Thus, the details of the construction and operation of the braking/shifting mechanism 22 will be omitted. However, the support member 21 and the braking/shifting mechanism 22 have been configured and arranged in the present invention to improve shifting. Accordingly, the braking/shifting mechanism 22 will only be discussed and illustrated in sufficient detail to make and use the present invention.
[0030] The support member 21 is configured as a box-shaped bracket that facilitates gripping. The support member 21 includes a mounting end portion 21 a configured and arranged to be coupled to the bicycle handlebar 13 and a distal end portion 21 b longitudinally spaced from the mounting end portion 21 a . A cover 21 c is disposed over the support member 21 . The mounting end portion 21 a has a band element or clamp 23 secured to the bicycle handlebar 13 . The distal end portion 21 b of the support member 21 has a pivot pin bore 21 d that pivotally supports the braking/shifting mechanism 22 to the support member 21 .
[0031] The braking/shifting mechanism 22 basically comprises a base member or adapter 31 , a cable winding mechanism 32 , a control (brake/shift) lever 33 and a release (shift) lever 34 . The control (brake/shift) lever 33 is operatively coupled to the cable winding mechanism 32 to wind or pull the wire 14 b to shift the rear derailleur 14 , while the release (shift) lever 34 is operatively coupled to the cable winding mechanism 32 to unwind or release the wire 14 b to shift the rear derailleur 14 . The braking/shifting mechanism 22 is pivotally connected to the support member 21 by a pivot pin 36 about a brake pivot axis P, which is a non-shift pivot axis. A torsion spring or biasing element 35 is mounted on the pivot pin 36 with one end of the torsion spring 35 engaging the base member 31 and the other end of the torsion spring 35 engaging the support member 21 to urge the braking/shifting mechanism 22 from a braking position to a normal rest position. In particular, the braking/shifting mechanism 22 is basically pivoted by the rider pulling or squeezing the control (brake/shift) lever 33 toward the handlebar 13 . Thus, the control (brake/shift) lever 33 pivots relative to the support member 21 between the braking position and the normal rest position.
[0032] Shifting, on the other hand, is basically performed by pivoting the control (brake/shift) lever 33 about a main shift pivot axis M, or pivoting the release (shifting) lever 34 about a secondary shift pivot axis S. The main shift pivot axis M extends longitudinally between the mounting end portion 21 a and the distal end portion 21 b of the support member 21 . In the illustrated embodiment, the main shift pivot axis M and the secondary shift pivot axis S are parallel.
[0033] The control (brake/shift) lever 33 has an attachment end portion 33 a , a shift operating portion 33 b and an extreme free end portion 33 c . The attachment end portion 33 a of the control (brake/shift) lever 33 is pivotally coupled to the support member 21 to move between a normal rest position and a shifting position about the main shift pivot axis M. The shift operating portion 33 b extends outwardly from the distal end portion 21 b of the support member 21 . As seen in FIG. 2, the shift operating portion 33 b of the control (brake/shift) lever 33 is configured and arranged to be disposed along a line L 1 that passes through the attachment end portion 33 a at the main shift pivot axis M. The line L 1 of the shift operating portion 33 b of the control (brake/shift) lever 33 represents the center longitudinal axis of the shift operating portion 33 b . This line L 1 of the shift operating portion 33 b of the control (brake/shift) lever 33 is angled relative to the main shift pivot axis M by approximately an angle A 1 that is between forty-five degrees and fifty-five degrees at the rest position. This arrangement allows for the rider to easily operate the control (brake/shift) lever 33 .
[0034] Still referring to FIG. 2, the bicycle control device 12 is secured to the handlebar 13 by the clamp 23 such that the tip of the extreme free end portion 33 c of the control (brake/shift) lever 33 is aligned with the free end of the handlebar 13 as seen in FIG. 2. Also, when the bicycle control device 12 is mounted in this position, the main shift pivot axis M forms a forty-seven degree angle with a ground level plane GL that represents ground level. The clamp 23 has a center clamping plane B that bisects the clamp 23 and is arranged perpendicular to the center axis C of the portion of the handlebar 13 where the clamp 23 is attached as seen in FIG. 2. Thus, the center clamping plane B extends perpendicularly from the bicycle handlebar 13 to intersect with the main shift pivot axis M at an intersection point to form an acute angle A 3 as measured upwardly from the clamping plane B and on a forward side of the main shift pivot axis M that away from the mounting end portion 21 a . Preferably, the acute angle A 3 measures approximately 4.5 degrees. This arrangement further allows for the rider to easily operate the control (brake/shift) lever 33 and the release lever 34 .
[0035] The release lever 34 is pivotally mounted on the control (brake/shift) lever 33 between the attachment end portion 33 a of the control (brake/shift) lever 33 and the shift operating portion 33 b of the control (brake/shift) lever 33 . The release lever 34 is operatively coupled to the cable winding mechanism 32 to release the wire 14 b of the shift cable 14 a as discussed below. The release lever 34 has an attachment end portion 34 a and a shift operating portion 34 b . The attachment end portion 34 a of the release lever 34 is pivotally coupled to the control (brake/shift) lever 33 to move between a normal rest position and a shifting position about the secondary shift pivot axis S. The shift operating portion 34 b extends along the rearward side of the shift operating portion 33 b of the control (brake/shift) lever 33 . The shift operating portion 34 b of the release lever 34 is configured and arranged to be disposed along a line L 2 that passes through the attachment end portion 33 a at the main shift pivot axis M. The line L 2 of the shift operating portion 34 b of the release lever 34 represents the center longitudinal axis of the shift operating portion 34 b . This line L 2 of the shift operating portion 34 b of the release lever 34 is angled relative to the main shift pivot axis M by approximately an angle A 2 that is between forty-five degrees and fifty-five degrees at the rest position. This arrangement allows for the rider to easily operate the release lever 34 .
[0036] The base member 31 is pivotally supported on the support member 21 by the pivot pin 36 . Thus, the base member 31 can not rotate about the main shift pivot axis M. More particularly, the base member 31 is a U-shaped member that has a fixing portion or plate 31 a and a pair of brake cable attachment portions or plates 31 b extending from the fixing portion or plate 31 a . The fixing portion or plate 31 a has a fixing hole 31 c that is used to secure the cable winding mechanism 32 thereto. The brake cable attachment portions or plates 31 b have axially aligned pivot holes 31 d that support the pivot pin 36 and axially aligned recesses 31 e that define a wire hook or brake attachment point in which the end of the brake wire 15 b of the brake cable 15 is attached.
[0037] The cable winding mechanism 32 is pivotally coupled to the support member 21 by the base member 31 . The cable winding mechanism 32 has a main support member or shaft 37 that defines the main shift pivot axis M and that rotatably supports the attachment end portion 33 a of the control (brake/shift) lever 33 via a bearing assembly 38 . The bearing assembly 38 and the attachment end portion 33 a of the control (brake/shift) lever 33 are removably attached to the support shaft 37 by a fixing screw 39 . The control (brake/shift) lever 33 pivots about the main shift pivot axis M that extends perpendicular to the brake pivot axis P. Thus, the control (brake/shift) lever 33 is operatively coupled to the cable winding mechanism 32 to pivot about the main shift pivot axis M. In other words, the control (brake/shift) lever 33 is swingable, for effecting speed change, in a direction perpendicular to the braking movement of the control (brake/shift) lever 33 .
[0038] A torsion return spring or biasing element 40 is mounted on the fixing screw 39 with one end of the return spring 40 engaging the attachment end portion 33 a of the control (brake/shift) lever 33 and the other end of the return spring 40 engaging an outer cap unit 41 that is non-rotatably secured to the support shaft 37 by the fixing screw 39 . The return spring 40 applies an urging force to the control (brake/shift) lever 33 in a first rotational direction for biasing the control (brake/shift) lever 33 from a shifting position to a normal rest position.
[0039] The base member 31 is secured to the support shaft 37 of the cable winding mechanism 32 by a nut 42 that is threaded on to the end of the support shaft 37 . In other words, the end of the support shaft 37 extends through the fixing hole 31 c of the fixing plate 31 a to secure the cable winding mechanism 32 thereto.
[0040] As seen in FIG. 7, a stationary plate 46 with a recess 46 a is mounted adjacent the distal end of the support member 21 to be non-rotatable relative thereto. The attachment end portion 33 a includes, adjacent its proximal end, a ball 47 for engaging the recess 46 a and a lever positioning spring 48 for urging the ball 47 into the recess 46 a . This construction acts to maintain the control (brake/shift) lever 33 in a neutral position opposed to the foremost end of the curved portion of the handlebar 13 , and to prevent the control (brake/shift) lever 33 from swinging with the release lever 34 when the latter is operated.
[0041] Referring to FIGS. 7 and 9, the cable winding mechanism 32 further includes a shift wire takeup element 50 , a position maintaining mechanism 51 formed by the release lever 34 and a control or release plate 51 a , a transmission element 52 coupled to the control (brake/shift) lever 33 , and a shift position sensor 53 disposed between the attachment end portion 33 a and the takeup element 50 . The shift position sensor 53 is used for detecting the current gear position that is engaged. The shift position sensor 53 can be a potentiometer as illustrated.
[0042] The takeup element 50 of the cable winding mechanism 32 has an approximately cylindrical shape with a shift cable attachment point 50 a in which the end of the shift wire 14 b of the shift cable 14 a is attached. The takeup element 50 is normal urged in a wire-unwinding direction by a return spring or biasing element 54 . In other words, the return spring or biasing element 54 is configured and arranged to apply a biasing force in a first rotational direction to urge the takeup element 50 to rotate in the wire-unwinding direction. The wire takeup element 50 also has a plurality of teeth or driven portions 55 located on the outer peripheral surface and a plurality of teeth or engaging portions 56 on an inside peripheral wall thereof.
[0043] As seen in FIG. 9, the transmission element 52 includes an engaging projection 52 a at a distal end thereof. The transmission element 52 is biased against the teeth or driven portions 55 of the takeup element 50 by a spring 52 b located in a recess of the control (brake/shift) lever 33 . Thus, pivotal movement of the control (brake/shift) lever 33 about the main shift pivot axis M causes the takeup element 50 rotate against the force of the return spring 54 .
[0044] The support shaft 37 further non-rotatably supports a pawl support body 57 that swingably supports a return pawl or engaging member 58 (FIG. 9) and a positioning pawl 59 (FIG. 7). A spring 60 is provided for urging the return pawl 58 toward the engaging portions 56 , while a spring (not shown) is provided for urging the positioning pawl 59 away from control recesses 61 that are formed on an inner peripheral surface of the takeup element 50 .
[0045] The release lever 34 is pivotally connected to the attachment end portion 33 a by a pivot pin 69 that defines the secondary pivot axis S. The pivot pin 69 extends parallel to the support shaft 37 . The release lever 34 includes a control projection 34 c projecting from the proximal end thereof in a direction opposite to the attachment end portion 34 a thereof. The control projection 34 c engages the control plate 51 a that is supported on the support shaft 37 . Movement of the release lever 34 rotates the control plate 51 a to release the takeup element 50 which is then rotated in the wire-unwinding direction by the return spring 54 .
[0046] The control plate 51 a includes engaging projections for engaging the return pawl 58 and the positioning pawl 59 , respectively, to move the return pawl 58 out of engagement and the positioning pawl 59 toward its engaging position when the release lever 34 is swung sideways. The control plate 51 a further includes a first cam surface for contacting the engaging projection 52 a of the transmission element 52 , and a second cam surface for engaging the control projection 34 c . The control plate 51 a , the return pawl 58 and the positioning pawl 59 operate in the same manner the corresponding elements of the fourth embodiment that is described in U.S. Pat. No. 5,241,878 (assigned to Shimano, Inc.). This allows change speed to be effected with the swinging movement in the direction perpendicular to the direction of pivotal movement of the control (brake/shift) lever 33 .
[0047] The release lever 34 is disposed in a recess defined in a back face of the attachment end portion 33 a . The attachment end portion 34 a of the release lever 34 is disposed close to the control (brake/shift) lever 33 , projecting toward the handlebar 13 relative to the attachment end portion 33 a for facilitating operation. The release lever 34 has a starting position in which one lateral face of the release lever 34 contacts a side surface of the recess of the attachment end portion 33 a.
[0048] In this illustrated embodiment, the control (brake/shift) lever 33 is pivotable to the braking position with a hand holding the curved portion of the handlebar 13 or the support member 21 . The control (brake/shift) lever 33 makes a pivotal movement on the brake pivot axis P. This pivotal movement of the control (brake/shift) lever 33 pulls the brake wire 15 b thereby to brake the bicycle 10 . The control (brake/shift) lever 33 can be swung sideways from the starting or rest position to provide a selected low speed, and returns to the starting or rest position under the force of the return spring 40 upon release. The release lever 34 can be swung sideways from its starting or rest position to provide a selected high speed, and returns to the starting or rest position under the forces of the spring urging the return pawl 58 and of the spring urging the positioning pawl 59 upon release.
[0049] When the control (brake/shift) lever 33 is swung in a sideways direction with the transmission element 52 engaging one of the driven portions 55 , the transmission element 52 drives the takeup element 50 , and the return pawl 58 moves away from the engaging portions 56 . As a result, the shift wire 14 b is pulled to provide a selected low speed. When the control (brake/shift) lever 33 is released, the control (brake/shift) lever 33 returns to the starting or rest position under the force of the return spring 40 .
[0050] When the release lever 34 is pushed in a sideways direction, the control plate 51 a is driven through the control projection 34 c . Then, the engaging projection of the control plate 51 a presses the positioning pawl 59 toward the control recesses 61 , whereby the tip end of the positioning pawl 59 advances into one of the control recesses 61 . The engaging projection of the control plate 51 a also moves the return pawl 58 out of engagement with an engaging portion 56 . As a result, the takeup element 50 returns by an amount corresponding to the gap between the positioning pawl 59 and the control recess 61 , i.e. within one pitch of the engaging portions 56 . When the release lever 34 is released to return, the control plate 51 a rotates to release the positioning pawl 59 out of engagement with the control recess 61 and to move the return pawl 58 into engagement with an adjacent engaging portion.
[0051] The release lever 34 is pivoted to the attachment end portion 33 a of the control (brake/shift) lever 33 so that, when the control (brake/shift) lever 33 is swung forward to effect speed change, the release lever 34 is swung with the control (brake/shift) lever 33 instead of moving relative to the latter. This allows the control (brake/shift) lever 33 to be swung without being obstructed by the release lever 34 .
[0052] In the illustrated embodiment so far described, the control (brake/shift) lever 33 is swingable in the direction perpendicular to the direction of pivotal movement of the control (brake/shift) lever 33 , i.e. axially of the brake pivot axis P. Instead, the control (brake/shift) lever 33 can be swingable in an inclined direction relative to the brake pivot axis P. It will serve the purpose if the control (brake/shift) lever 33 is swingable in a direction different from the direction of pivotal movement of the control (brake/shift) lever 33 within a range that does not result in a change speed at times of braking.
[0053] When braking the bicycle with a hand holding the lower extreme position of the curved portion of the dropped handlebar 13 , the cyclist can extend the index and middle fingers, for example, of the hand holding the curved portion, hook the control (brake/shift) lever 33 and draw the control (brake/shift) lever 33 toward the braking position, i.e. toward the curved portion. This lever operation causes the cable winding mechanism 32 to pivot on the brake pivot axis P with the base member 31 . This pivotal movement of the control (brake/shift) lever 33 pulls the brake wire 15 b thereby to brake the bicycle 10 .
[0054] The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.
[0055] While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
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A control device is configured to be attached to the handlebar of a bicycle for controlling a brake mechanism and change speed mechanism. The control device comprises a bracket fixed to the handlebar, a brake lever pivotally coupled crosswise relative to the bracket and a release lever. The brake mechanism is controlled by fore and aft pivotal movement of the brake lever, while the change speed mechanism is controlled by sideways pivotal movement of the brake lever and the release lever. The brake lever and the release lever are further configured relative to the bracket for smooth easy operation by the rider.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/EP2009/005296, filed Jul. 21, 2009, which designated the United States and has been published as International Publication No. WO 2010/012405 and which claims the priority of German Patent Application, Serial No. 10 2008 035 515.1, filed Jul. 30, 2008, pursuant to 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
The present invention refers to sintered abrasive grain agglomerates with a portion of aluminum oxide of at least 80% by weight, an average primary particle diameter of less than 5 μm, an substantially spherical outer shape, with a portion of pores of at least 15% by volume and a mean agglomerate size in the range between 5 μm to 500 μm.
The present invention also refers to a process for producing sintered abrasive grain agglomerates as well as their use as lapping agents for the production of organically or inorganically bonded abrasive bodies, for the production of abradants used on a substrate as well as in wear protection layers.
Abrasive grain agglomerates are known in many variations for some length of time and normally are used in connection with bonded abradants such as for example abrasive disks, or abradants on substrates such as for example abrading belts. Abrasive grain agglomerates are normally constructed from single abrasive grains, the primary particles that are bonded together by means of a binder into a abrasive grain agglomerate. As binding agents either organic or inorganic binders can be utilized, wherein phenol resins are oftentimes used as organic binders, while glass-like or ceramic binders are used as inorganic bonding agents.
The big advantage of abrasive grain agglomerates is in fact that finely grained abradants can be utilized as primary particles from which an agglomerate grain is then formed which, as compared to a single grain of comparable size, exhibits an entirely different wearing mechanism during the abrading- and wearing process. A single grain of comparable size, according to pressure conditions, either dulls during the abrading process, or it will be destroyed. In contrast, with the abrasive grain agglomerate, the abrading conditions are selected so that single grains break out from the compound, such that new cutting edges are constantly formed which lend the agglomerate grain a long life expectancy while showing a cool smoothness and a homogenously polished section. A further advantage of the abrasive grain agglomerate is that in this manner, the finest abrasive grains can be utilized for abrading processes and abrading tools, for which they are otherwise not suited due to their small grain size.
In DE 103 92 532 B4, abrasive grain agglomerates are described which comprise a multitude of abrasive grains that are held together with a bonding agent, wherein the bonding material has a melting temperature in the range of 500° C. to 1400° C. In DE 103 92 532 B4, a method for the production of such abrasive grain agglomerates is also described, wherein the abrasive grains are mixed with a bonding agent and subsequently are subjected to a heat treatment in a revolving furnace in a temperature range of 145° C. to 1300° C. The agglomerates that are thus obtained have a total porosity between 35% by volume and 80% of volume, wherein at least 30% by volume of the pores are interconnected. In this process, elongated agglomerates are formed that have a length ratio of length to cross section of at least 5:1. As a bonding agent, glass-like bonding materials, vitrified materials, ceramic materials, inorganic bonding agents, organic bonding agents and combinations of these are utilized. The so obtained abrasive grain agglomerates should be most of all used in bonded abradants in order to control the properties of porosity and the porosity in the form of a permeable and interconnected porosity.
In DE 10 2005 007 661 A1, abrasive bodies are described that are formed and bonded together by means of a bonding agent into abrasive grains in material union and exhibiting at least approximately a spherical outer shape, wherein the abrasive grains have a porosity of at least 35% by volume. These abrasive grain agglomerates are formed from single abrasive grains, with a particle size in the range between of 0.05 μm and 150 μm, which are then joined with abrasive grain agglomerates with an outer diameter in the range of 10 μm and 150 μm. In the abrading tools, these agglomerates are utilized that are graded narrowly, as quasi constant grainings. Binders that are preferred are organic binders, such as for example phenol resins, polyurethane, epoxide resins, urea resin and poly vinyl butyral. These agglomerate abrasive grains are meant especially for utilization with abradants on substrates where they are used for very fine abrasive treatment of work piece surfaces.
Although the production of abrasive grain agglomerates is in principle relatively uncomplicated and is based simply on mixing together single abrasive grains with a bonding agent to then form an abrasive grain agglomerate that is subsequently heat treated, in practice, technical process problems occur in nearly all known methods for obtaining homogenous and evenly formed agglomerates with respect to the size of the agglomerates, as also with respect to the shape of the agglomerates and the composition of the agglomerates. These problems originate mostly when very fine abrasive grains of medium size of a few microns are mixed with a binder and subsequently are heat treated.
When utilizing solid binders the problem might already be based on the fact that the size of the particles of the binding agent is coarser than those of the abrasive grains to be bonded and makes any homogenous mixing harder. When using liquid binders or those diluted with solvents, the problem is oftentimes that the abrasive grains lump together, whereby a homogenous distribution of the bonding agent in the abrasive grain granulation is prevented and the production of a homogenous product made more difficult.
A further technical problem of the method, in particular when utilizing organic binders is the contamination of the apparatus used, as the mixtures of binder and abrasive grains tends to conglutinate at the walls of the apparatus. Therefore, this leads, in particular when changing products, to high cleaning maintenance, and when producing agglomerate grains, since the desired abrasive grain agglomerate of abrasive grains composed of a narrow grain size has to be realized. Such contamination with coarser grains would lead to considerable problems, for example, in abrading operations where it mostly concerns the superfine treatment of work piece surfaces, such as, for example, the treatment of decorative lacquer layers could lead to considerable problems if such contamination with coarse grains caused scratches, which subsequently would needed to be removed, if even possible, with a considerable amount of work. With bonding agents, aside from them causing contamination in the apparatus, environmental protection is also a concern, since the use of organic solvents or binders are mostly associated with annoyances such as bad smell as well as health risks.
Thus, as a basis for solving this problem, the object of the present invention was to provide abrasive grain agglomerates that do not suffer from the drawbacks of the prior art.
SUMMARY OF THE INVENTION
Object of the present invention is also to provide a method for the production of abrasive grain agglomerates that do not exhibit the type of technical problems with the methods of the prior art.
The problem, respectively the object is solved by sintered abrasive grain agglomerates including primary particles on the basis of aluminum oxide with
a) a portion of aluminum oxide of at least 80% by weight
b) a mean primary particle diameter of less than 5 μm
c) a substantially spherical outer shape
d) a portion of pores of at least 15% by volume and
e) a mean agglomerate size in the range between 5 and 500 μm, wherein the primary particles are interconnected without an additional binding agent, as well as a method for the production of these abrasive grain agglomerates by the following steps:
a) wet comminuting a calcined aluminum oxide in an agitator ball mill with comminution bodies of aluminum oxide and/or stabilized zirconium oxide,
b) spray drying or spray granulating the comminuted aluminum oxide dispersion resulting in agglomerate green bodies and
c) sintering the agglomerate green bodies in a temperature range between 1300° C. and 1750° C. Advantageous embodiments of the abrasive grain agglomerates according to the present invention are subject of the corresponding dependent claims.
The sintered abrasive grain agglomerates according to the present invention are composed of primary particles on the basis of aluminum oxide, wherein the portion of aluminum oxide is at least 80% by weight. The mean primary particle diameter is under 5 μm and the agglomerates themselves are substantially of a spherical outer shape. The sintered abrasive grain agglomerates are not dense form bodies, but agglomerates with a portion of pores of at least 15% by volume at a mean agglomerate size in the range between 5 μm and 500 μm. In contrast to the prior art, the primary particles of aluminum oxide are interconnected without an additional bonding agent.
In order to realize reproducible abrading results, it is desired that the pores in a abrasive grain agglomerate are distributed homogenously, wherein the pore diameter should be also within a narrow range. In the abrasive grain agglomerate according to the present invention, the pores have a mean diameter of less than 2000 nm, preferably less than 1000 nm. Especially good results are realized with abrasive grain agglomerates that show a mean pore diameter between 100 nm and 300 nm.
As afore-stated, normally an even pore distribution is desired in order to obtain constant product properties. It is however also possible and can be advantageous, especially also through a suitable selection of the sinter temperature, to alter the porosity of the product and in that manner to adjust the product properties to specific purposes of application.
Advantageously, the mean primary particle diameter is below 3 μm, preferably below 1 μm and especially below 0.5 μm. The bulk density of the abrasive grain agglomerates is between 1.4 and 2.9 kg/l, whereby the abrasive grain agglomerates exhibit a specific surface (BET) between 3 and 0.1 m 2 /g. The specific surface is influenced especially by the sintering temperature, whereby starting from a specific surface of the agglomerate body of about 20 m 2 /g at a sintering temperature of 1450° C., a specific surface of about 2 m 2 /g is reached, whereas at a higher sintering temperature, a stronger compression of, the agglomerate takes place and, for example, at 1550° C., a specific surface of only about 0.3 m 2 /g is measured.
As the stability of the agglomerate does not suffice to determine a grain breaking strength according to Vollstädt, a single grain breaking strength test was forgone and instead, comparable compression tests with agglomerate green bodies and agglomerates were conducted. As expected, it was shown that the agglomerate green bodies can be compressed easily, whereas the sintered abrasive grain agglomerates allow for only a small amount of compression. The final compression strength of the abrasive grain agglomerates is, as expected, higher than that of the agglomerate green bodies. After compression tests, the agglomerate green bodies are present as compact bodies, while the sintered abrasive grain agglomerates flow out of the press mold in quasi undestroyed condition. The compression tests were conducted in a simple brass ring as pressure mold into which the agglomerates were filled and then placed under pressure by means of a pressure piston with pressures up to 200 N.
The abrasive grain agglomerates preferably have a content of at least 90% by weight aluminum oxide, especially preferred at least 98% by weight. The chemical composition in certain ranges can vary according to need and preferred embodiments of abrasive grain agglomerates are provided which in summary contain up to a maximum of 20% by weight of compounds from the group of elements tungsten, titanium, chrome, zirconium, magnesium, silicon, boron, carbon and/or nitrogen, relative to the total weight of the abrasive grain agglomerate. These compounds can be provided as oxides, carbides or nitrides, whereby they may be already present as impurities in the raw material or they can be admixed during wet comminuting, respectively subsequent to the wet comminuting or, as the case may be, can be indirectly brought into the suspension as rubbed-off parts from the grinding medium.
In this context, it should be noted that the present invention also includes further possibilities that comprise the principle of the invention, namely to produce composite work material in agglomerate form, wherein the agglomerate according to the present invention quasi represents the composite base and by admixing corresponding compounds, composite agglomerates with defined portions of other hard materials or other minerals can be realized. The mean grain size of such hard material or minerals can be smaller, equal or also larger than each of the primary particles of the base material.
The method for producing of abrasive grain agglomerates starts with the wet comminution of a calcined aluminum oxide in an attritor, wherein as grinding medium aluminum oxide beads or grinding beads of stabilized zirconium oxide are preferably utilized. As raw material, a finely calcined aluminum oxide is preferably used, which is ground for the production of a suspension by means of a wet comminution, ground to or deagglomerated to a mean particle size of less than 5 μm, preferred less than 1 μm, and especially preferred less than 0.5 μm. Advantageously, the comminution is carried out by means of a vibration mill, an attritor, or a stirring apparatus ball mill. The suspension, after comminuting has most often solid matter content between about 5% by weight and about 70% by weight, preferred between about 30% by weight and about 60% by weight. According to need, organic stabilizers can be added as dispersion aids to the suspension. The comminuting preferably takes place in water, with the possibility of also adding other solvents, for example alcohols, ketones, or other polarized organic liquids, however ecological, economic and safety concerns speak against such use.
The drying of the comminuted aluminum oxide dispersion is carried out by means of spray drying, resulting in agglomerated green bodies. Which, after drying, contain a maximum residual moisture content of about 6% by weight. Especially advantageous is an intermediate product with a residual moisture content of less than 1% by weight.
Due to suitable selection of drying conditions (amount of hot air, liquid pressure, spray tower dimensions), the agglomerate size of the product can be adjusted to a relatively narrow range. In this manner, there is no problem to obtain agglomerates in the size range between 5 μm, and 500 μm. By means of predetermined adjustment of the drying parameters, the agglomerate green bodies can be obtained in a size between 30 μm and 300 μm. A further classification can be done through a subsequent screen out.
The so obtained agglomerate green bodies are then sintered in a temperature range between 1300° C. and 1750° C. No particular properties are required for the sintering method and so cylindrical rotary kilns, sliding batt kilns or oven-type furnaces can be utilized. From a technical standpoint it is advantageous, to conduct the sintering directly in a cylindrical rotary kiln, where high heat rates and short duration rates can be realized. The preferred temperature range is between 1400° C. and 1550° C.
The abrasive grain agglomerates obtained in this manner can be advantageously utilized as lapping agents as well as for the production of organically and inorganically bonded abrasive bodies and for the production of abradents on a substrate. In addition, areas of use are in wear protection coatings on the basis of inorganic, organic or elastomeric composite systems, such as for example solvents- or water-containing dyes, lacquers and powder lacquers or enamel. A further area of application is the use of impregnates in the production of wear resistant surfaces for floor coverings, such as for example laminates, parquet or PVC or CV-covering, for furniture, tiles, cooking pots and/or cooking pans.
BRIEF DESCRIPTION OF THE DRAWING
In the following paragraphs, the present invention is more specifically described based on the figures and examples.
It is shown in:
FIG. 1 a scanning electron microscope image of a section of abrasive grain agglomerate sintered at 1450° C. in a 3000 fold enlargement,
FIG. 2 a scanning electron microscope image of a section of abrasive grain agglomerate sintered at 1550° C. in a 3000 fold enlargement,
FIG. 3 a scanning electron microscope image of a surface of an abrasive grain agglomerates in 1000 fold enlargement,
FIG. 4 a scanning electron microscope image of a bulk of an abrasive grain agglomerates in 30-fold enlargement,
FIGS. 5-8 each a pore distribution curve measure via mercury porosimetry of differently screened out abrasive grain agglomerate fractions sintered at 1450° C.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
After it was surprisingly found that solid and relatively compact abrasive grain agglomerates that are exceptionally suitable for grinding operations, can be obtained through simple sintering and without the use of binder agents, optimization of those abrasive grain agglomerates was worked on. Thereby, it was found that the porosity of the agglomerates plays a major role for the subsequent use as abrasive grain agglomerate. FIG. 1 illustrates a section of a scanning electron microscope image of abrasive grain agglomerate sintered at 1450° C. in 3000-fold enlargement. Thus, it is shown that a relatively large portion of pores (dark areas), which in this case are homogenously distributed across the almost ideally spherical abrasive grain agglomerate. From the illustration, it is seen that the pore size is markedly below 2000 nm, approximately in the range of about 100 nm and 300 nm. The agglomerate diameter is about 30 μm.
FIG. 2 shows a screen electron image of almost equally large abrasive grain agglomerate in section also in 3000-fold enlargement, wherein the abrasive grain agglomerate in this case was sintered at 1550° C. In a direct comparison with FIG. 1 , it is easily seen that the abrasive grain agglomerate sintered at 1550° C. in the center is essentially denser and that due to the higher sintering temperature, obviously a compression of agglomerates has taken place. The abrasive grain agglomerate according to FIG. 2 is thus composed less homogenously, which has a negative impact especially when used in certain abrading operations and here especially, when used for abradants on substrates. It was found that an even distribution of fine pores has a positive impact on the abrading result and that excessive sintering of the product normally must be avoided, if optimal result is desired. Depending on the application, it can be advantageous, to produce deliberately more dense and less porous materials that can be utilized for special applications. An example for such applications is the wear protection of very thin lacquer coatings. The compact very finely grained aluminous abrasive grains that are normally utilized have a pore free and relatively smooth surface, from which, upon mechanical stress, the aluminous abrasive grains easily break out from the coat of lacquer.
The agglomerate grain as illustrated in FIG. 2 shows a porous surface (or coating) of a compact core. With a suitable liquid lacquer system, this porous surface, when using the agglomerate grain as wear protection, can be infiltrated in a thin lacquer layer due to its capillary property and after corresponding hardening of the lacquer, a material-interconnecting engagement between the agglomerate grain and lacquer layer with an increased bonding stability results. At the same time, the core that has not been sintered possesses a higher compression strength as compared to a homogenous porous agglomerate grain.
FIG. 3 is directed to a scanning electron microscope image of the surface of abrasive grain agglomerate in 10000-fold enlargement. This illustration shows especially the primary particle diameter, whereby in this case, the mean primary particle diameter is markedly below 1 μm.
FIG. 4 shows a scanning electron microscope image in 30-fold enlargement of a multitude of abrasive grain agglomerates. Thus, an agglomerate size distribution is shown, as it normally occurs in spray drying. The largest single agglomerates are in the range of about 200 μm, while the smallest agglomerates have an agglomerate size of about 20 μm to about 30 μm. Depending on the application for the abrasive grain agglomerates, certain fractions can be screened out without problems, such that for later abrading or wear protection applications, depending on need, relatively narrow grain distributions can be readily provided.
Further investigations relative to pore distribution were conducted, which are explained in more detail by means of FIGS. 5-8 and described in more detail in the following paragraphs by means of corresponding tabulated measurements.
The graphic representation of pore size distribution in FIG. 5 of an abrasive grain agglomerate fraction sintered at 1450° C. having an agglomerate size between 0 μm and 32 μm is summarized in the following Table 1.
TABLE 1
Pore size distribution
General agglomerate data
(Hg-Porosimetry)
Sintering temperature:
Pore size
Relative pore
1450° C.
(μm)
volume (%)
Agglomerate fraction:
110-57
2.08
0-32 μm
57-30
2.49
Bulk density:
30-15
4.46
1.58 g/cm 3
15-8
52.87
Specific surface:
8-4
12.86
2.10 m 2 /g
4-2
2.63
Total porosity:
2-1
1.48
61.04%
1-0.6
0.82
Mean pore diameter:
0.6-0.3
1.59
8.56 μm
0.3-0.1
18.23
0.1-0.05
0.44
0.05-0.01
0.05
In the graphic illustration of the above tabularized pore size distribution it is seen that the distribution is bimodal with a maximum of pores in the range from 15 μm to 8 μm and a further maximum in the range from 300 nm to 100 nm. As can also be shown later through the coarser agglomerate fractions, the bimodal distribution can be attributed exclusively to the measurement method, since in the mercury porosimetry agglomerate bulk is measured, wherein not only the pores in the agglomerates are measured, but most of all also the empty spaces between the single particles of the bulk. At an agglomerate size between 0 μm and 32 μm, the diameters of these spaces are between 15 μm and 8 μm. The actual pores that characterize the abrasive grain agglomerate are in the range from 300 μm to 100 μm. The measured total porosity thus does not relate to the single abrasive grain agglomerate, but again, relates to the bulk, wherein the porosity of the abrasive grain agglomerate itself in the present case is only at about 19% by volume.
In FIG. 6 , the pore size distribution for an abrasive grain agglomerate fraction sintered at 1450° C. in the range from 32 μm to 75 μm is graphically represented. The corresponding measurements are summarized in the following Table 2.
TABLE 2
Pore size distribution
General agglomerate data
(Hg-Porosimetry)
Sintering temperature:
Pore size
Relative pore
1450° C.
(μm)
volume (%)
Agglomerate fraction:
110-57
3.38
32-75 μm
57-30
25.31
Specific surface:
30-15
36.28
2.16 m 2 /g
15-8
4.4
Bulk density:
8-4
1.96
1.86 g/cm 3
4-2
0.54
Total porosity:
2-1
1.47
54.86%
1-0.6
0.2
Mean pore diameter:
0.6-0.3
0.37
44.16 μm
0.3-0.1
26.29
0.1-0.05
0.78
0.05-0.01
0.00
In this case there is likewise a bimodal distribution of pores size, wherein the empty spaces between the single agglomerate particles and the agglomerate fraction between 32 μm and 75 μm is also shifted into the coarser range and in the range between 60 μm and 15 μm exhibit a maximum. Unchanged is the maximum of the pore size distribution of the pores that are associated with the agglomerate grain in the range from 100 nm to 300 nm. In the present case, the abrasive grain agglomerate has a porosity of about 27% by volume while the total porosity of the bulk is at 54.9% by volume. The measured mean pore diameter of the bulk is at 44.2 μm. This result is almost exclusively due to the large empty spaces between the single abrasive grain agglomerates and does not permit to draw a conclusion on the mean pore diameter of the abrasive grain agglomerate itself.
FIG. 7 shows a graphic illustration of the pore size distribution of an abrasive grain agglomerate fraction sintered at 1450° C. in the range from 150 μm to 250 μm. The respective measured results are summarized in Table 3.
The graphics shown in FIG. 7 likewise shows a bimodal function, where a maximum of fine pores in the range from 100 nm to 300 nm is shown, while the coarser pores show a maximum range of 110 μm to 57 μm. In this relatively coarse abrasive grain agglomerate fraction with 150 μm to 250 μm, the empty spaces between the single abrasive grain agglomerates, which are measured in the mercury porosimetry, show a correspondingly large diameter, which in this case is at 110 μm to 75 μm. The total porosity of the bulk lies at 56.8% by volume, while porosity of the abrasive grain agglomerates itself are at about 30.1% by volume.
TABLE 3
Pore size distribution
General agglomerate data
(Hg-Porosimetry)
Sintering temperature:
Pore size
Relative pore
1450° C.
(μm)
volume (%)
Agglomerate fraction:
110-57
48.82
150-250 μm
57-30
12.7
Specific surface:
30-15
3.85
2.15 m 2 /g
15-8
1.7
Bulk density:
8-4
0.89
1.96 g/cm 3
4-2
0.24
Total porosity:
2-1
0.21
51.29%
1-0.6
0.18
Mean pore diameter:
0.6-0.3
0.09
56.75 μm
0.3-0.1
30.76
For the range 0.01 to
0.1-0.05
0.57
10 μm: 0.194 μm
0.05-0.01
0.00
(computed)
The direct comparison between the single abrasive grain fractions shows that the abrasive grain agglomerates themselves are almost exclusively marked by nanoscale pores in the range between 100 nm and 300 nm.
In order to measure the true mean pore diameter, further measurements were conducted, in which only the range between 1 μm and 10 nm was used to determine the mean pore diameter.
FIG. 8 shows in a graphic representation, the pore size distribution of the abrasive grain agglomerate fraction sintered at 1450° C. in the range from 150 μm to 250 μm. As can be seen, the cut-off pore size range above 10 μm has the effect that with 0.194 μm an essentially more realistic mean pore diameter is computed for the abrasive grain agglomerate, wherein the coarse pore range of the empty spaces does not have that much importance anymore.
In the following examples, the production as well as the use of the abrasive grain agglomerates according to the present invention are described.
EXAMPLE 1
Commercially available calcined aluminum oxide (Nabalox No.: 713-10 RF, Fa. Nabaltec) is ground in a stirrer ball mill using Y-stabilized zirconium oxide grinding balls to a mean grains size between 0.35 μm and 0.55 μm in wet condition. The particle size of the particle in the about 50% suspension was determined by means of a Sympatec-Helos-grain size measurement apparatus. A particle size of D 90% =0.85 μm, D 50% =0.44 μm, and D 10% =0.2 μm was determined. The surface was determined to 20.6 m 2 /g (BET). This suspension was subsequently spray dried, wherein the grain size of the agglomerate was set in the range from 0 μm to 200 μm. Subsequently, a sintering operation followed in the oven-type furnace at different sinter temperatures, wherein the agglomerate green body each were held for about 30 minutes at the predetermined sintering temperature. Samples were each taken at 1450° C., 1500° C. and 1550° C. sintered.
EXAMPLE 2
From the agglomerate grain fraction produced as in Example 1 that were sintered at different temperatures, a more narrow grain size range was screened out, which was adjusted to a FEPA-grain F100. For the following tests a special fused alumina grain was also utilized as grain 100 (ALODUR WSK, Fa. Treibacher). Of each of the four grainings, an aqueous suspension was produced, in which each 3 g of abrasive grain was mixed with 40 ml of distilled water. These suspensions were each put in a stainless steel vessel and subjected to an ultrasound finger (20 kHz, 200 Watt) for 10, 15, 20, 25 and 30 minutes each. The suspensions were then transferred into glass flasks and after undergoing a 2 day settling period their settling behavior photographically documented and evaluated.
The high grade corundum white (ALODUR WSK, Treibacher) shows even after a treatment time of 30 minutes only a small amount of chipping at the stainless steel vessel as well as on the ultrasound finger. The chipped metal particles are relatively coarse and sediment well, so that for all treatment periods an almost clear solution remains.
The abrasive grain agglomerate sintered at 1450° C. in contrast, shows a markedly higher chip removal. Thus, the chipped metal particles are very small, so that quasi no sedimentation occurs and the solutions even after two days are dark gray to black.
The abrasive grain agglomerates sintered at 1500° C. cause markedly worse chipping and a constant turbidity of the solution is first recognized in the sample with a treatment period of 30 minutes, while the remaining samples are sedimenting.
The abrasive grain agglomerate sintered at 1550° C. behaves comparably to the high grade corundum white and even at 30 minutes treatment time an almost clear solution remains.
This behavior is explained by the increasing binding stability that occurs with increasing sintering temperature between the primary particles, the increasing crystal formation due to increased sintering temperature and the decreasing pore volume at increased sintering temperature.
EXAMPLE 3
For the simulation of an ultrasound-lapping process, and analogous to example 2, various lapping suspensions having a higher solid content portion were produced. Therefore, 100 g solid matter (abrasive grain agglomerate or high grade corundum) was added to 120 ml water.
The ultrasound finger was form-fittingly connected with a matt finish sheet metal of Cr—Ni-stainless steel, as well as in a further test, with a matt finish sheet metal of an aluminum-alloy.
After a lapping period of each 30 minutes, the surface of the test sheet metals were examined. It could be determined that the suspension with the abrasive grain agglomerates sintered at 1450° C. had the lowest surface roughness. Comparison was made with an high grade corundum suspension as well as suspensions of abrasive grain agglomerates sintered at 1500° C. and 1550° C. These results thus correlate with the micro chip removal results found in example 2.
EXAMPLE 4
After it was surprisingly found that the porous agglomerates exhibit a marked capillarity and are quickly and easily filled through infiltration with liquids, such as for example, aqueous or oil based liquid lubrication material, further tests in this direction were conducted.
An agglomerate graining sintered at 1450° C. screened for a grain size in the range between 60 and 100 μm was infiltrated by simple mixing in an intensive mixer with poly methylsiloxane-oil (Fa. Bayer, Baysilon ÖI M50) or a corresponding oil emulsion (Fa. Bayer, Baysilon Ölemulsion). Thus, the dry flow capacity of the mixtures were used as a measure of the amount of oil necessary to complete infiltration, wherein this case, up to an amount of ca. 16 ml emulsion or 14 ml oil per 100 g agglomerate grain, a still flow capable mixture was realized.
400 g of agglomerate grain was infiltrated with 40 ml emulsion from which grinding belts were produced for the treatment of lacquer surfaces in automobiles. As a reference, a grinding belt with non-treated agglomerates was produced. The production of the belts themselves was carried out through wet coating of an agglomerate grain/resin-suspension by means of a wiping blade to a support and subsequent hardening.
The lacquer surface was then treated with abrading disks that had been stamped out from the grinding belts by means of a conventional eccentric grinding machine. In the subsequent measuring of the surface roughness, it was found that the belts with the infiltrated agglomerates, as compared to the bands with the non-treated agglomerates, effected a lower mean surface roughness and thus showed a finer polished section, which in particular, proves advantageous in the surface treatment of auto body lacquers. This refined polish section can be possibly based on an in situ oil lubrication during polishing.
The afore-described results show that the sintered porous abrasive grain agglomerates are suited as grinding-lapping- or polishing agents.
For applications in bonded abradents, where normally high contact pressures are applied which cannot be resisted by the abrasive grain agglomerate having a homogenous pore distribution, the more compact abrasive grain agglomerates sintered at higher temperatures can be of advantage. The same is applicable also to the use in wear protection coating, whereby the type of wear and the wear mechanism will be determinative.
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The present invention relates to sintered abrasive grit agglomerates based on aluminum oxide, having homogeneously distributed nanoscale pores in the range of 100-300 nm, with a pore volume of at least 15%. The average diameter of primary particles of the aluminum oxide primary particles is less than 5 μm, wherein said primary particles are connected to each other without additional adhesive agent.
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This is a division of application Ser. No. 07/284,546 filed Dec. 15th, 1988 now U.S. Pat. No. 4,901,926.
BACKGROUND OF THE INVENTION
The invention relates to a tub having at least one nozzle, built into the vicinity of the tub wall for introducing a water-and-air mixture, which communicates via a pressure line with the pressure side of a pump, the intake side of which communicates via a pipeline with an intake opening in the vicinity of the bottom of the tub.
Tubs of this type, which as a rule can be installed like a standard bathtub, are used in such a way that for a "whirlpool bath", the tub is filled and emptied after the bath in the usual manner. Care must be taken when emptying the tub that the pump system pipelines, including the pump, are emptied as well, to prevent bacterial growth.
In relatively large-capacity tubs of this type, in which the tub or pool is kept filled over a relatively long period of time and is used several times before refilling, water-conditioning devices, in particular filters, are provided in the pipeline system so that germs can largely be prevented from forming in the water. In pools of this type as well, care must be taken that the pipeline system be emptied completely as well when the water is changed, so that when the pool is refilled, contamination of the freshly drawn water is avoided.
From German Patent 34 20 714, a whirlpool tub is known in which the pipeline system, via a system of level sensors and controllable valves, is equipped such that when it is filled, the entire pipeline system is first flushed with fresh water, so that any of the old water that may still remain is flushed out into the drain line and can no longer get into the water filling the tub when the swirl nozzle system, which functions by recirculation, is put into operation.
It has now been found that flushing with fresh water is no longer adequate over a relatively long period of time. The entire pipeline system that carries water must therefore be treated from time to time in a separate cleaning operation, in which a cleaning and/or disinfecting solution is poured into the tub along with the fresh water. Especially in whirlpool tubs used in private homes, either this additional operation is omitted completely or it is performed at such long time intervals that the danger that the water filling the tub will become contaminated by sources of bacteria in the pipeline system cannot be precluded.
The automatically closing nozzles known previously are not only complicated in their structure, because of the required pivotability of the nozzle body, but also have disadvantageous housing shapes, which do not permit complete emptying and/or satisfactory flushing with a cleaning agent. Moreover, a defined supply of the air via an air line protruding into the nozzle body is not possible, so that the previously known closable nozzle forms can admix air only in the suction mode, and the connection of an air compressor, or in other words an air supply that takes place independently of the flow through the nozzle, is not possible.
SUMMARY OF THE INVENTION
It is an object of the invention to embody a whirlpool tub such that each time the whirlpool bath is put into operation, both when it is refilled and when the swirl nozzle system is put into operation after the tub has been completely filled, a thorough flushing of the entire pipeline system, separately from the tub interior, can be performed, together with the addition of a cleaning and/or disinfecting agent.
The above and other objects are accomplished according to the invention by the provision of a fluid system, including: a pump which has a suction side and a pressure side; a nozzle for introducing a water-and-air mixture into the tub; the nozzle having a nozzle portion; a pressure line connecting the pressure side of the pump with the nozzle portion; a suction opening provided in a bottom region of the tub; and a suction line connecting the suction side of the pump with the suction opening; the improvement including:
(a) a valve provided in the nozzle portion for cutting off fluid flow to the tub;
(b) an overflow line having a closable vent opening; the overflow line being coupled to the suction side of the pump;
(c) a device for selectively allowing or blocking fluid communication between the overflow line and the suction line of the pump: and
(d) a supply source for introducing a cleaning agent at a location upstream of the nozzle as viewed in a direction of fluid flow therethrough.
The closability of the nozzles with respect to the interior of the tub makes it possible to flush the entire pipeline system separately, either with fresh water or with fresh water and a solution of cleaning agent and/or disinfecting agent, before each use of the swirl nozzle system. This can be done both upon refilling of the tub and when a tub is already completely filled. The overflow line between the nozzle and the suction line enables the circulatory flushing action to occur. If the overflow line is shut off from the suction line, the tub can be operated in the whirlpool mode with the nozzle opened. With both the tub and the pipeline system completely empty, the vent opening makes it possible to fill the pipeline system completely first, and in so doing to vent it, upon refilling the tub and/or when performing a separate cleaning operation, with the aid of the pump. The feeding of the cleaning and/or disinfecting agent, hereinafter referred to as the cleaning agent, is suitably effected upstream of the pump, so that satisfactory mixing of the cleaning agent with the water can be effected in the pump itself.
In another feature of the invention, the overflow line is closable with respect to the suction line by a preferably closable shutoff valve. In a further embodiment of the invention, the overflow line, at a location downstream of the nozzle, has a branch line which is closable with a closable shutoff valve and which discharges into the tub drain pipe. This embodiment makes possible the establishment of definite pressure conditions in the pipeline system for the various operating modes. The disposition of the branch line that can be shut off enables emptying the part of the overflow line located below the level of the tub completely as well. If the shutoff valve of the overflow line is completely opened and the shutoff valve of the branch line is not completely closed during cleaning, then, while simultaneously supplying fresh water, it is possible to remove some of the circulated water from the tub interior via the intake opening in the vicinity of the bottom of the tub, and then, once the cleaning operation is completed, to flush the pipeline system with fresh water and flush out all of the cleaning agent solution by simultaneously shutting off the overflow line from the suction line and completely opening the shutoff valve in the branch line. For whirlpool operation, the shutoff valve of the branch line is then closed as well, so that once the tub interior has been filled completely and with the nozzle now open, whirlpool operation can take place.
In a feature of the invention, the vent opening can be shut off with a shutoff valve which preferably a float valve, so that once the overflow line has been completely vented, the pipeline system can be subjected to circulating water and/or a cleaning agent solution.
In another advantageous feature of the invention, the nozzle has a shutoff body which keeps the pressure line closed off from the tub interior at a pump pressure between zero and a first low pressure level and automatically opens if the first pressure level is exceeded. While the above described cleaning operation can also be performed using manually closable nozzles instead of the nozzle having the shutoff body, this feature permits automatic operation, particularly if, via a corresponding control circuit, the shutoff valve in the overflow line and in the branch line are also triggerable and are actuated as a function of the pressure in the pressure line, or as a function of a fill level in the interior, or via a timing program. It is particularly advantageous if, as in a further feature of the invention, a pump of variable and preferably infinitely regulatable rpm is provided, which in combination with a level sensor switches the pump drive motor so that, when a minimum fill level in the tub is exceeded, a pumping capacity is used that results in a pump pressure lower than the first pressure level. This assures that, with a nozzle that opens automatically as a function of pressure, and with correspondingly opened shutoff valves in the overflow line and/or branch line, the fluid carried in the pipeline system via the pump cannot enter the tub interior.
While it is in principle possible to connect the pipeline system to the tub interior via a separate intake opening, a preferred embodiment of the invention provides that the intake opening of the suction line that communicates with the tub interior is disposed in a chamber-like tub drain fitting, in which the tub drain opening drains into the chamber-like tub drain fitting and the tub plug is disposed below the mouth of the intake line, the overflow line discharges above the tub plug, and the branch line discharges below the tub plug into the tub plug fitting. This makes it possible to combine the drain opening, which is necessary in any case, with the intake opening of the pump suction line, and at the same time to combine the overflow line, or its branch line, selectively with either the suction line or the drainpipe in one fitting. By disposing the mouth of the intake line of the overflow line in the chamber-like tub drain fitting at a location above that of the tub plug, it is also possible, given a suitable embodiment of the relevant flow cross sections, to flush the pipeline system thoroughly with a cleaning agent solution as well, without requiring an additional plug for the intake opening and without this cleaning agent being capable of entering into the tub interior. This can be assured if, when the shutoff valve is slightly open, the pump draws fluid in an amount via the suction line from the chamber-like connection fitting such that, in addition to the quantities of fluid received from the overflow line, a small quantity of fluid is also drawn from the tub interior via the intake opening.
The invention also relates to an automatically closing nozzle for introducing a mixture of water and air into a tub, in particular a tub of the type described above. This nozzle has a support ring, by way of which a prechamber communicating with the pressure line is firmly joined to the tub wall and with which a retaining ring is releasably connected, and wherein a nozzle body embodied as a ball is pivotably held in the support ring. The nozzle body has a bore that communicates with the prechamber, and the mouth of an air supply line protrudes into the bore externally of the tub.
To overcome the problems of the prior art set forth hereinabove, the invention provides that the retaining ring is embodied as a plunger and is retained axially displaceably in the support ring and is supported on its side remote from the prechamber via compression spring elements; that the bore of the nozzle body has, on its end oriented toward the mouth of the air supply line, an annular sealing element circumscribing an entrance to the bore; and that the outside of the mouth of the air supply line has an external surface portion which is spherical, the nozzle body being urged against this spherical surface portion by the compression spring elements such that the sealing element seats against it. A nozzle embodied in this way, having a rigid air supply line protruding into the nozzle body, can be closed independently of the pivoted position of the spherical nozzle body, when no pressure is applied to the prechamber. Only when the pressure applied to the prechamber creates a force on the plunger that is greater than the closing force of the compression spring elements, does the sealing element lift from the spherical face of the mouth of the air supply line and free the connection between the prechamber and the interior of the tub. The closing force of the compression spring elements is designed such that it is higher than the plunger force that corresponds to the pressure in the prechamber during the flushing operation. Particularly in the case where an only slightly deformable material is used for the annular sealing element, it is advantageous for the center of the spherical face of the mouth of the air supply line to coincide with the center of the spherical body when the sealing element is in contact with the spherical face.
In a further feature of the invention, the ends of the compression spring elements which are remote from the prechamber are braced against an adjusting ring which is axially adjustable with respect to the mouth of the air supply line. With the aid of such an adjusting ring, it is possible on the one hand to vary the flow cross section of the nozzle for control of the flow of water through the nozzle independently of the pumping capacity of the pump, so that even when pumps not having a regulatable pumping capacity are used, it is possible to vary the quantity of water emerging through the nozzle. On the other hand, it is possible to close the nozzle completely by hand as well, so that the nozzle body with its annular sealing element is pressed firmly against the spherical outside face of the mouth of the air supply line, so that even when a high pressure prevails in the prechamber the nozzle does not open. This is particularly important for nozzles of tubs which permit pre-flushing of the system, of the type according to the invention. During normal operation and with a nozzle that automatically opens if the first pressure level is exceeded, a solution of cleaning agent can be pumped only "gently", in other words with a low flow velocity through the pipeline system, without causing opening of the nozzle. When the nozzle is closed by movement of the adjusting ring, it is possible to flush out the pipeline system with the full pump power, so that instead of or in addition to the chemical action of the cleaning agent, a mechanical cleaning action can be attained via high flow velocities. In an advantageous embodiment, the adjusting ring is accessible from the interior of the tub and includes at least one handle element.
In another advantageous feature of the invention, the adjusting ring and the retaining ring are joined together in a manner fixed against relative rotation but such that they are axially displaceable relative to one another. This arrangement has the advantage that, upon an actuation of the adjusting ring, no relative rotational movement between the adjusting ring and the retaining takes place, so that the compression spring elements, upon an adjustment, are not strained in the transverse direction, therefore precluding jamming or tilting thereof.
In still another feature of the invention, the space surrounding the spring elements is vented. This has the advantage that the automatic closing and opening function of the nozzle is maintained, even if after a relatively long period of operation the plunger seals were to become leaky so that the equilibrium pressure will not build up in the space surrounding the spring elements, so that the spring elements would keep the plunger in the closing position even at operating pressure. Thus via the vent opening, not only can the air volume in this space escape, but any fluid that has entered it can escape as well, so that when the prechamber is pressurized, an unequivocal pressure difference can always exist between the prechamber and the space surrounding the spring element.
In a further advantageous embodiment of the invention, the plunger is provided, on an end thereof which is oriented toward the prechamber, with a scraper, which in the closing position of the nozzle protrudes into the prechamber. By means of a scraper of this kind, which may also be part of the plunger seal, it is assured that when the system is depressurized lime deposits that form on the associated inner cylindrical face of the support ring are mechanically removed, to facilitate reciprocation of the plunger in the support ring even after a long period of operation.
In nozzles for use with tubs having the pre-flushing of the system according to the invention, a further feature of the invention is that the prechamber, on its upper side, has a connection piece for connection to an overflow line. This makes it possible to vent the prechamber completely when the cleaning solution is introduced, with the action of the pump causing filling of the prechamber.
In a further advantageous embodiment of the invention, the prechamber is provided on its lower side with an inlet opening which has at least two branches which are preferably oriented at right angles from one another. This arrangement has the advantage that for smaller tubs, in which only two nozzles per tub side are provided, the nozzles can be disposed at the same height, and the pressure line connecting the two nozzles together as well as the pressure line extending from the pump to the first nozzle, when viewed in the flow direction, can be laid practically without a slope, so that when the system is emptied the liquid can flow back out of the prechamber to the pump. This makes installation considerably simpler, because it becomes largely unnecessary to provide additional fittings.
In another advantageous feature of the nozzle according to the invention, the air supply line protrudes at an angle extending from top to bottom through the prechamber into the bore of the nozzle body. This arrangement has the advantage that the part of the air supply line located in the vicinity of the nozzle can also be completely emptied when the system is emptied.
The invention also relates to a tub drain fitting for tubs with system pre-flushing, in particular for a tub of the type according to the invention that can be connected to the drain opening of the tub. This tub drain fitting includes a flow chamber disposed beneath the bottom of the tub, the flow chamber having an upper opening that terminates in the form of a drain opening into the tub interior, and has a lower opening that discharges into the drain pipe and is closable with a valve body which is externally actuatable, the flow chamber above the valve body having two preferably diametrically opposed flow openings, wherein one of the flow openings is connectable to an inflow line and the other is connectable to a suction line. A tub drain fitting embodied in this way has the advantage that the tub drain opening also serves as an intake opening for the suction line of the pump, so that when the inflow line is closed, water can be carried out of the tub interior via the pump through the nozzles in a circulating loop (whirlpool operation). When the inflow line is opened, then depending on the relative sizes of the cross sections of the intake line on the one hand and the inflow line on the other, the inflow line preferably having a smaller cross section, the quantity of fluid flowing in from the inflow line is introduced in jet form directly into the intake line, so that an overflow of the fluid from the inflow line into the tub interior is avoided. Instead, a slight drag flow is generated, which carries some of the fluid along with it out of the tub itself via the suction line. During a flushing operation, in particular during a flushing operation using a solution including a cleaning agent, the cleaning agent solution is prevented from getting into the tub interior.
In another embodiment of the invention, the opening connectable to the inflow line has a pipe extension protruding into the flow chamber toward the other opening. As a result, the quantity of fluid arriving from the inflow line operates in the manner of a jet pump with respect to the drain opening of the tub.
In an advantageous embodiment of the invention, the opening communicating with the tub interior communicates via a pipe insert with the drain opening located beneath it, the pipe insert having a smaller diameter than the inside diameter of the flow chamber, and the wall of the pipe insert, on the side of the opening of the flow chamber communicating with the suction line, is provided with at least one flow opening. In this arrangement, the opening of the flow chamber serving as the drain opening of the tub is shielded from the inflow line, so that the water flowing from the inflow line is prevented from flowing directly into the tub interior. At the same time, the pipe insert, with its flow openings oriented toward the opening of the suction line, prevents the unhindered passage of the water from the tub interior into the suction line, so that a normal whirlpool operation is assured.
The invention will be described in greater detail below with reference to an embodiment which is illustrated in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a whirlpool tub and the associated a pipeline system in accordance with the invention.
FIG. 2 is a side elevational view of a nozzle for the tub of FIG. 1.
FIG. 3 is a side sectional view taken along the line III--III of FIG. 2.
FIG. 4 is a side sectional view of a drain fitting for the pipeline system of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A whirlpool tub 1 is schematically shown in FIG. 1 having the form of a relatively large bathtub which is provided in a conventional manner with a drain opening 2 in the vicinity of a tub bottom 1', the drain opening 2 communicating with a drainpipe 3. A tub drain 5 also communicates in a conventional manner with the drainpipe 3 via a pipeline 4.
On each of its two opposed long sides, the tub 1 has two nozzles 6, through which a mixture of water and air can be introduced in jet fashion into the tub interior when the bathtub is filled. The nozzles 6, which are described hereunder in further detail with reference to FIG. 2, have pivotable nozzle bodies, so that the jet direction is freely adjustable within predetermined limits.
A pressure line 7, having horizontal portions 7' and 7", connects the nozzles 6 with the pressure side of a pump 8, which in turn communicates via a suction line 9 and a drain fitting 10 with the drain opening 2. The drain opening 2 serves as an intake opening for the pump 8 to provide recirculation of water in the tub 1. The drain fitting 10 has a valve body 11 therein which is closable to prevent fluid flow into the drainpipe 3, the valve body 11 being externally actuatable. The pump 8 is disposed horizontally, such that its intake opening is oriented downwardly, so that when the pump is stopped and the valve body 11 is opened, the pressure line 7 can drain through the pump 8 into the suction line 9, which drains into the drainpipe 3 until it is completely empty.
The nozzles 6 also communicate with an air supply line 12, through which the nozzles 6 draw air, via either the draft action of the water flowing into the tub space or via a connected compressor (not shown), so that air can be introduced along with the water into the tub 1 in the form of a jet-like water-and-air mixture injected by the nozzles 6. The air intake opening of the air supply line 12, during a suction operation, and alternatively the air compressor if used, are preferably adjustable such that the quantity of air introduced to the nozzles can be regulated.
The pressure line 7 discharges upwardly into a prechamber 30 of the nozzles 6, shown in FIG. 2, that is disposed on the outside of the tub 1. The prechamber 30 is connected at its top to an overflow line 13. The overflow line 13 is described in further detail hereunder in conjunction with FIGS. 2 and 3.
The overflow line 13 has a horizontal section 13"' connected to a vertical section 13' which supplies both a discharge section 13" and a branch line 15. The discharge section 13" is connected to a shutoff valve 14 which, when open, enables discharge of liquid into the drain fitting 10 above the valve body 11 via a drain line 62. The branch line 15 is likewise closable with respect to th drain fitting 10 or the drainpipe 3 via a shutoff valve 16 which, when open, enables discharge of liquid directly to the drainpipe 3. A supply container 17 is provided to supply a cleaning and/or disinfecting agent and is connected to the suction line 9 via a shutoff valve 19 and a supply line 18.
The overflow line 13 also has a vent fitting 20, preferably extending upwardly as far as the height of the rim of the tub 1 and forming a vent opening for the overflow line 13. Branching off from the vent fitting 20 is a transverse line 21 which communicates with the overflow line 4. An automatic valve, for instance a float valve 22, is disposed in the vertical section 13'of the overflow line 13 at a height above that of the horizontal section 13"' and below that of the transverse line 21 so that only relatively slight quantities of fluid, equivalent to leakage, can pass from the overflow line 13 into the pipeline 4 via the transverse line 21.
The vertical portion 13' of the overflow line 13 is connected to a level sensor 23, the control signal of which is sent to a control unit 24. The level sensor 23 is located at a height corresponding to a predetermined minimum fill height, for instance 10 cm, with respect to the tub bottom 1'. A further level sensor 25, which is also connected to the control unit 24, is provided in the vent fitting 20 above the float valve 22.
The signals supplied by the level sensors 23 and 25 to the control unit 24 are used to control the drive motor of the pump 8 in such a way that the pump 8 cannot be switched on until the minimum fill height, which is predetermined by the height of the level sensor 23, has been attained, and such that even then the pump 8 is controlled to have only a relatively low pumping capacity. Only when the operating fill height predetermined by the level sensor 25 is attained can the pump 8 be switched on with full pumping capacity.
The pipeline system is preferably controlled, as described in further detail below in conjunction with FIG. 2, so that when the nozzles 6 are closed, the shutoff valve 14 is open, and the shutoff valve 16 in the branch line is closed upon attainment of the minimum fill height predetermined by the level sensor 23, so that the pump 8 can pump fluid in a circulating loop which includes the pressure line 7, the overflow line 13 (including the horizontal section 13"', the vertical section 13' and the discharge section 13"), and the suction line 9. The drain fitting 10 here is embodied such that no fluid, or only slight quantities of fluid, can reach the suction line 9 from the interior of the tub 1 during operation of the circulating loop, as will be described in further detail below in conjunction with FIG. 4. Upon opening of the shutoff valve 19, a cleaning or disinfecting agent can then be added in metered fashion, so that a solution of cleaning agent can be circulated through the pipeline system, e.g. through the circulating loop. When the shutoff valve 16 is open, the solution flows through the branch line 15, the drain line 29, and the overflow line 13 without coming into contact with the tub interior.
If the shutoff valves 14 and 16, and optionally the shutoff valve 19 as well, are equipped with controllable operating drives, they also can be connected to the control unit 24, so that both the triggering of the pump 8 and the triggering of the shutoff valves 14 and 16, and optionally the shutoff valve 19, can be effected via the control unit 24 in accordance with a predetermined switching program. It is also possible in this respect for the shutoff valve 16 to be opened slightly during the cleaning operation, so that a partial flow of cleaning agent solution is always drained into the drainpipe 3, and corresponding quantities of fresh water from the tub interior or from a fresh water supply, can enter the suction line 9. After the completion of the cleaning procedure, the shutoff valve 16 is opened completely and the shutoff valve 14 is closed completely, so that, together with a simultaneous aspiration of fresh water from the interior of the tub 1 through the drain opening 2, the pipeline system carrying the water (comprising the suction line 9, the pressure line 7 and the overflow line 13), can be flushed completely with fresh water. After this flushing process is completed, the shutoff valve 16 is closed.
Since upon the beginning of the cleaning process the pump 8 functions only at a low pumping capacity, it is additionally possible to fill the pipeline system relatively slowly on the pressure side of the pump 8, so that the quantities of air contained therein (i.e., in the pressure line 7, each prechamber 30 of the nozzles 6, and the overflow line 13), can escape via the vent fitting 20. In this case, the pipeline system continues to be filled slowly until the overflow system is also completely filled, i.e. in this case until the vertical section of the overflow line 13 is also completely filled, whereupon the float valve 22 finally closes.
During the cleaning operation, the filling of the tub can be continued, because only when the operating fill height predetermined by the level sensor 25 is reached can the pump 8 be switched to full capacity. Via a corresponding locking circuit, (e.g. in the control unit 24,) it can be assured that only upon the closure of the shutoff valve 16, after the completion of the flushing with fresh water, is pump operation at full capacity possible. With manually closed nozzles 6, these nozzles must first be opened. With automatically closing nozzles, the very much higher pump pressure during whirlpool operation as compared with the cleaning operation is sufficient to open the nozzles.
In the inflow region, each of the nozzles 6 are provided with three connection fittings 26, 27, and 28, wherein the connection fillings 26 and 28 are aligned horizontally and the connection fitting 27 is oriented vertically, so that with the arrangement shown, a portion 7" of the pressure line 7 extending between the two nozzles 6 communicates with the horizontally aligned connection fittings 26 and 28, while a portion 7' of the pressure line 7, which is located between the pump 8 and the first of the nozzles 6 in the flow direction, is connected to the connection fitting 27 which points downwardly. This assures satisfactory drainage of the water when the pipeline system is emptied.
In FIG. 2, a particular embodiment for an automatically closing nozzle 6 is shown. The nozzle 6 includes a prechamber 30, having the horizontally extending connection fittings 26, 28 at a bottom portion thereof (also shown in FIG. 3) beneath which extends the vertically downwardly pointing connection fitting 27. On the top of the nozzle 6 is a connection fitting 31 for attachment to the portion 13"' of the overflow line 13. The prechamber 30 is secured to and sealed against the outside of a side tub wall 1" of the tub by a clamping collar 41 which has a sealing face contacting the side tub wall 1" and a generally cylindrical support ring 32 having an axis A which is engaged within an interior of a nozzle support wall 6' by a threaded connection. The side tub wall 1" extends outwardly from the interior of the tub 1 at an inclination of angle α, for example, from the vertical, and therefore the central axis of the support ring 32 is also tilted from the horizontal at an angle α. In the support ring 32 is disposed a retaining ring 33 which is embodied as an axially displaceable plunger and which has circumferentially arranged seals.
A nozzle body 34 is embodied as a ball-like portion having a center of curvature M, and which is pivotably retained in an annular portion 33' of the retaining ring 33. The nozzle body 34 has a tubular mouth 35 that can direct a jet of fluid into the tub interior.
The retaining ring 33 is biased toward the prechamber 30 via a plurality of compression spring elements 36 distributed generally uniformly in the radial direction about the axis A. An adjusting ring 37 is fastened within the support ring 32 by a threaded connection, and serves as an end stop for the retaining ring 33. The adjusting ring 37 also has at least one guide pin 38 which engages the inside of an axial bore 39 in the retaining ring 33, so that the retaining ring 33 is guided by the guide pin 38 during movement thereof in the axial direction relative to the adjusting ring 37. Since the adjusting ring 37 is retained in the support ring 32 via a threaded connection, the adjusting ring 37 and the retaining ring 33 can be rotated relative to each other about the common axis A, and can thereby be relatively axially displaced. As a result of the resilient spring coupling between the retaining ring 33 and the adjusting ring 37 formed by the springs 33, the axial play between the displaceable retaining ring 33 and the adjusting ring 37, as well as the spring biasing force (within certain limits), can be adjusted. The adjusting ring 37 is provided with a handle element 40 accessible from the inside of the tub, which is for instance in the form of a rib, and which can also be embodied as a recess. An ornamental cap 42 covers the clamping collar 41 of the support ring 32 and has an innermost cylindrical flange which serves as a limitation of the axial adjustment of the adjusting ring 37 in the direction toward the inside of the tub 1.
The nozzle body 34 has a bore therethrough which communicates with the prechamber 30 and widens in the axial direction toward the prechamber 30. An annular sealing element 43 is disposed adjacent an innermost diameter of the bore and is supported by the nozzle body 34 on the side of the bore which is oriented toward the prechamber 30. An air supply member 44 is oriented within the prechamber 30 in a generally axial direction relative to the axis A and, in the exemplary embodiment shown, is inclined slightly counterclockwise from the horizontal and extends into the bore of the nozzle body 34. The air supply member 44 has a mouth 46 which protrudes into the bore in the nozzle body 34 and has a tip having a generally spherical outer face portion 45 which cooperates with the annular sealing element 43 to form a seal. In an unpressurized state of the prechamber 30, the nozzle body 34 is pressed, along with its sealing element 43, against the outer face portion 45 via the compression spring elements 36. The interior of the bore of the nozzle body 34 contacts the outside face 45 of the mouth 46 at a contact surface of the nozzle body 34 which is formed as a generally spherical interior face portion mating with the outside face 45 so that the nozzle body 34 can be pivoted relative to the retaining ring 33 without causing the sealing element 4 to lift from the face 45 of the mouth 46. Therefore, in any arbitrary angular position of the nozzle body 34, the seal is maintained between the interior of the tub 1 and the prechamber 30.
As a result of the disposition of the retaining ring 33 relative to the nozzle body 34 with respect to the prechamber 30, any buildup of fluid pressure within the prechamber 30 effects a plunger force on the nozzle body 34 oriented counter to the force of the compression spring elements 36. The plunger force acting on the nozzle body 34 can overcome the closing force of the compression spring elements 36 only if the fluid is in excess of a predetermined pressure level. When this pressure level is exceeded, the nozzle body 34, together with its seal 43, are lifted away from the counterpart face 45 of the mouth 46, so that water supplied to the prechamber 30 can flow into the tub interior. For a pipeline system having a pre-flushable line system, the closing force of the compression spring elements 36 can be adjusted by rotation of the retaining ring 33 relative to the support ring 32, such that at a relatively small minimum pumping capacity of the associated pump 8, the nozzles 6 are securely closed, and such that the nozzles 6 are securely opened only after the very much higher pumping capacity required for whirlpool operation has been initiated.
By rotation of the adjusting ring 37 relative to the support ring 32 to cause movement of the adjusting ring 37 in the direction of the prechamber 30, however, it is possible to suppress the pressure-dependent axial motion of the retaining ring 33 and to press the nozzle body 34 against the mouth 46, so that the pipeline system can be flushed thoroughly with the full pumping capacity of the pump 8, without discharge of the cleaning solution into the tub 1.
The retaining ring 33 includes an edge region having a scraper 47, which, when the fluid pressure is cut off, protrudes into the prechamber 30, so that lime deposits can be scraped off of the cylindrical interior face of the support ring 32 or cannot form there in the first place.
FIG. 2 illustrates the retaining ring 33, which moves as a unit with the nozzle body 34 and the tubular mouth 35 connected to it, in two positions thereof (split above and below the axis A) relative to the adjusting ring 37 and to the outside face 45 of the air supply member 44. The closed position is shown above the axis A, wherein the annular sealing element seats against the outside face 45. The open position is shown below the axis A, wherein the retaining ring is moved to the left relative to its closed position, until it abuts the adjusting ring 37.
Whenever the nozzle body 34 is resting sealingly on the mouth 46, communication between the tub interior and the prechamber 30 is interrupted. At the same time, water can flow into the air supply member 44 when the tub is filled. However, because the air supply member 44 is inclined, it is reliably emptied when the tub 1 is emptied. In the exemplary embodiment shown, the communication of the air supply member (not shown) with the air line 12 is effected by lateral connection fittings 48, so that the additional possibility of an axial connection remains, for example for connection of an air compressor (not shown). In the exemplary embodiment shown, however, the axial inflow connection is closed with a plug 49. As shown in FIG. 3, unnecessary connection fittings can be closed by a plug, for example the connection fitting 26 is closed as shown by the plug 63.
As FIG. 2 shows, the movable parts of the nozzle 6 are accessible at any time from the tub interior, without having to remove the arrangement from the tub 1. To this end, all that needs to be done is to loosen the ornamental cap 42 and then to remove the adjusting ring 37 along with the retaining ring 33 embodied as a plunger. The seals of the parts which are movable relative to one another can then be replaced, or the plunger element (the retaining ring 33) can be replaced.
In FIG. 4, an exemplary embodiment for the drain fitting 10 is shown. The drain fitting 10 has a body 50 which defines an upper chamber portion 64, a lower chamber portion 65, and a discharge connection portion 66. The upper chamber portion 64 includes a flow chamber 50', which is firmly connected via a clamping ring 51 to the drain opening 2 in the bottom of the tub 1. The flow chamber 50 has a connection fitting 52 on its lower end, with which it is connected to the drainpipe 3 (not shown in FIG. 4). A valve body 53 is disposed in the lower region of the flow chamber 50 and can be raised from the closed position, shown, into an open position via an opening mechanism (not shown).
The flow chamber has a flow opening member 54 having an opening therein of large diameter disposed above the plane of the valve body 53, and is in the form of a connection fitting, which is disposed diametrically opposite a second flow opening member 55, which is likewise in the form of a connection fitting. The flow opening member 55 has a flow opening having a smaller flow cross section than that of the flow opening member 54. The suction line 9 of the pump 8 is connected to the flow opening 54, and the overflow line 13 of the pipeline system described in conjunction with FIG. 1 is connected to the flow opening 55.
A pipe insert 56 is disposed in the body 50 and has a smaller diameter than the flow chamber 50' itself. The side of the pipe insert 56 which is oriented toward the flow opening 54 has a plurality of openings 57, while on the opposite side, oriented toward the flow opening 55, the pipe insert 56 has a completely closed wall. With suitable dimensioning of the openings 57, water is prevented from flowing in to the tub interior during the flushing process via the flow opening member 55 in the direction of the arrow 58.
The valve body 53 has an extension 59 on its top which is connected to a cover cap 60 provided with holes. When the valve body 53 of the drain fitting 10 is closed, the hole in the cover cap 60 serve as a means to connect the inflow opening in the flow opening member 55 to the suction line 9. When the valve body 53 is opened, the cover cap 60 is raised as well, so that a sufficient flow cross section for a rapid emptying process is available. The openings 57 in the pipe insert 56 are disposed such that the inflow lines communicating with the openings 55 and 54 ca likewise be emptied completely via the drain fitting 10. Below the valve body 53, a further flow opening 61, likewise in the form of a connection fitting, is provided, into which the branch line 15 discharges.
The present disclosure relates to the subject matter disclosed in German Application No. P 37 42 437.2, the entire specification of which is incorporated herein by reference.
It will be understood that the above description of th 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 of the appended claims.
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A tub including a fluid system has a pump which includes a suction side and a pressure side; a nozzle for introducing a water-and-air mixture into the tub; the nozzle having a nozzle portion; a pressure line connecting the pressure side of the pump with the nozzle portion; a suction opening provided in a bottom region of the tub; and a suction line connecting the suction side of the pump with the suction opening. The fluid system further has a valve provided in the nozzle portion for cutting off fluid flow to the tub; an overflow line having a closable vent opening and being coupled to the suction side of the pump; a device for selectively allowing or blocking fluid communication between the overflow line and the suction line of the pump; and a supply source for introducing a cleaning agent at a location upstream of the nozzle as viewed in a direction of fluid flow therethrough.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a friction disc for use in false twisting, and a false twisting spindle provided with such discs.
2. Description of the Prior Art
Texturising by false twisting is a technique which is in itself well known and is widely used, and which consists basically in continuously overtwisting a thermoplastics yarn, fixing the yarn when so deformed, in particular by the action of heat and of a subsequent cooling treatment, and finally untwisting the yarn by the amount to which it was twisted.
It has long been known to impart a false twist to a moving yarn by means of discs (see in particular U.S. Pat. No. 1,030,179 in the name of Hilden) and it has also been proposed to use this idea for false twist texturising, for which purpose friction discs are arranged spaced from one another to rotate on axles which are essentially parallel to one another, the discs overlapping each other (see especially French Pat. Nos. 1,202,393 and 1,255,922 in the name of Scragg and 1,261,747 in the name of Zavody).
The spindles most widely used at present for this purpose in general comprise three rotating axles supporting the discs, the axles being so arranged that as seen in plan view they are at the apices of an equilateral triangle. The discs overlap one another so that the yarn to be treated passes through the unit following a zig-zag path between the discs.
In general, each axle supports several superposed spaced apart discs, the discs of one axle being staggered relative to those of adjacent axles so that they overlap one another.
The friction discs generally have a simple shape, with a convex peripheral surface which the moving yarn contacts, and upper and lower surfaces which are generally planar.
Various materials have been used for producing such friction discs. Currently, the materials which give the best results and which are tending to replace the originally used polyurethanes are ceramic. Ceramics are generally insensitive to chemical agents, which is extremely valuable bearing in mind the number of chemicals used in sizings deposited on the yarns, and furthermore have high resistance to wear and high heat resistance which makes it possible to achieve high speeds, as well as very high hardness and freedom from fouling. Furthermore, the properties of ceramic are easily reproducible, which makes it possible to replace friction discs without altering the quality of the yarn, and which ensures that the quality is uniform from one position of the machine to another. Currently, the majority of friction discs are produced from solid ceramics, which has the advantage of very high reproducibility, though use of discs of which only the surfaces are coated with ceramic has been considered.
The three-axle spindles which are currently marketed essentially consist of a horizontal support on which are perpendicularly mounted the axles carrying their friction discs. These axles are connected to one another and are driven synchronously by a belt connected to a drive pulley.
The friction discs each possess a convex peripheral surface against which the yarn makes contact, and the discs partially overlap one another, with the spacing between two discs generally being of the order of 0.5 millimeter.
These devices are generally satisfactory, but it has been found that during continuous operation a slight deposit can form on the non-working surfaces of the discs, this usually arising from sizings of the yarns. Furthermore, the production of these discs requires rather high precision, in view of the fact that it is necessary that the yarn should, as far as possible, be in contact over an arc of the same length with each friction disc.
SUMMARY OF THE INVENTION
According to the present invention there is provided a friction disc for use in false twisting, the disc having a convex peripheral surface to be contacted by a yarn and the disc having, on one or both of its upper and lower surfaces, a recess, a sharp edge being defined at a position between the recess and the convex peripheral surface.
It has been found that such discs can be manufactured to larger tolerances while ensuring satisfactorily uniform contact with yarns, and that, surprisingly, they do not require such frequent cleaning compared to prior discs produced from the same material.
In a simple embodiment, the recess is cut into a small part of the thickness of the disc in the zone immediately adjacent to the convex peripheral surface, and the join of the outer side wall of the recess and this convex peripheral surface is the sharp edge. The outer side wall of the recess may be cylindrical.
In a variant, the recess has a concave curved surface of small radius of curvature intersecting the convex peripheral surface and forming the sharp edge therewith. The said concave curved surface may lead inwardly to a part conical surface leading to the external face of the disc.
The depth of the recess is generally small and is advantageously between 0.3 and 1 millimeter, a depth of 0.5 millimeter being suitable in the majority of cases.
Furthermore, the width of the recess, where the latter is of annular shape, is generally between 3 and 10 millimeters, a width of 4 to 5 millimeters generally being sufficient.
In addition, the sharp edge can be separated from the convex friction surface by a plane zone of small width, of the order of 0.05 millimeter to 1 millimeter, which, without affecting the functioning of the disc, makes it possible to enjoy larger manufacturing tolerances and hence to reduce the cost price.
Discs according to the invention are preferably ceramic, though discs of, for instance, metal or of any other suitable material can be used.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, the following description is given, merely by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a side view of a frictional false twist spindle equipped with discs in accordance with the invention;
FIGS. 2 and 3 are respectively a cross-section and a top view of a disc according to the invention;
FIG. 4 is a partial sectional view showing another embodiment of disc according to the invention; and
FIG. 5 illustrates, on a larger scale a modified disc of the type illustrated in FIGS. 2 and 3 in partial cross section.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the description which follows, like reference numerals are used to denote like parts.
As can be seen in FIG. 1, a false twist texturising spindle operates by passing a yarn over rotating parallel discs and essentially comprises a fixed base 1 adjacent which travels a tangential drive belt 2, a drive pulley 3 mounted on a shaft substantially at right angles to the base 1 and to be driven by the tangential belt 2, and three sockets 4, 5 and 6, also mounted on the base 1, parallel to the drive pulley 3, and respectively supporting three rotationally driven axles 7, 8 and 9, on which are mounted, at right angles, friction discs 10.
In conventional manner, the axles 7, 8 and 9 are located at the apices of a triangle, so that the friction discs mutually overlap so as to define a zig-zag path for the yarn.
As can be seen in FIGS. 2, 3, 4 and 5, the friction discs 10 each have a convex peripheral surface 11, with which the yarn 12, during its travel, is in contact, and an upper face 13 and a lower face 14 which are generally planar.
According to this invention, each disc possesses, on at least one and preferably both of its upper and lower faces 13, 14, a recess 16 of which the bottom is joined to the convex peripheral surface 11 by a surface which forms a sharp edge 15. Thus, in the embodiment illustrated in FIGS. 2 and 3, each recess 16 is of annular shape and has a bottom 20 joined to the convex peripheral surface 11 by a cylindrical surface 21, the intersection between the two surfaces 11 and 21 being a sharp edge 15.
FIG. 4 illustrates another embodiment in which each recess 16 is of annular shape and consists of concave surface 18, of small radius of curvature, which intersects the convex peripheral surface 11 and forms, with the latter, a sharp edge 15. The concave surface 18 is extended inwards by a surface 19 of part conical shape, which leads to the external surfaces 13 and 14.
FIG. 5 illustrates a modification of the discs of the type illustrated in FIGS. 2 and 3, in which the sharp edge 15 is separated from the convex friction surface 11 by a planar zone 21 of small width. Examples of discs according to the invention will now be described.
EXAMPLE 1
Friction discs as illustrated in FIGS. 2 and 3, and having the following characteristics, were produced:
material: ceramic-trademark Tital TS 14
thickness: 6 millimeters
external diameter: 45 millimeters
depth of the recess 16: 0.5 millimeter
width of the recess 16: 4 millimeters
distance of the edge 15 from the axle: 19.5 millimeters.
A false twist spindle as illustrated in FIG. 1 was constructed using such discs, the adjacent surfaces of the discs being spaced 0.5 millimeter apart and the distance between the axles being 33 millimeters.
EXAMPLE 2
Example 1 was repeated, but a plane surface 22 of about 0.2 millimeter was formed at the surfaces of the discs, after forming the recesses 16, as illustrated in FIG. 5.
This embodiment made it possible to obtain convex friction surfaces 11 which were very precise whilst increasing the manufacturing tolerances, and to do so without affecting the functioning of the spindle produced with the aid of such discs.
Compared to similar spindles using friction discs produced from the same material but not possessing a sharp edge in the vicinity of the convex friction surface, it was found that the required frequency of cleaning of the friction components was substantially reduced. Furthermore, the yarns obtained possessed identical properties from one position to another, due to the greater uniformity of friction from disc to disc.
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A friction disc for use in false twisting has a convex, yarn contacting, peripheral surface and a recess on one or both faces adjacent the periphery, there being a sharp edge between the peripheral surface and recess.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/EP2007/054029, filed Apr. 25, 2007 and claims the benefit thereof. The International Application claims the benefits of European application No. 06011629.0 filed Jun. 6, 2006, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
The invention relates to a machine component with a base body which is manufactured from a base material and which in a section of its surface is provided with a cladding consisting of a cladding material with a greater hardness in comparison to the base material. Furthermore, it relates to a gas turbine with a number of machine components of this type.
BACKGROUND OF THE INVENTION
Turbines, especially gas turbines, are used in many areas for driving generators or driven machines. In this case, the energy content of a fuel is used to produce a rotational movement of a turbine shaft. For this purpose, the fuel is combusted in a combustion chamber, wherein air, which is compressed by an air compressor, is supplied. The working medium, which is produced in the combustion chamber by means of the combustion of the fuel, is guided in the process at high pressure and at high temperature through a turbine unit, which is connected downstream to the combustion chamber, where it is expanded, performing work.
For producing the rotational movement of the turbine shaft, in this case a number of rotor blades, which are customarily assembled to form blade groups or blade rows, are arranged on said turbine shaft and drive the turbine shaft via an impulse transmission from the working medium. For guiding the working medium in the turbine unit, moreover, stator blade rows, which are connected to the turbine casing, are customarily arranged between adjacent rotor blade rows.
A turbine of this type comprises a large number of component parts or machine components which are suitably positioned in the turbine, subject to predetermined measurements, shapes and/or tolerances. In many cases, it can be desirable in the process to minimize the contact of adjacent machine components or component parts with each other, in order to keep wear of the affected component parts especially low by such means. However, during the operation of the turbine, time and again actually unwanted contact between such component parts can develop, for example as a result of thermal expansions or else as a result of operation-induced vibrations or suchlike which occur, so that certain wear of such component parts occurs. As such machine components, for example a so-called flame tube, a mixing chamber and an inner casing are customarily arranged adjacent to each other in the region of the combustion chamber of the gas turbine. Owing to their design, these machine components have such significant deformations and critical tolerances that during operation of the gas turbine contact between these component parts in some places is unavoidable. As a result of this contact, unwanted and possibly also critical wear, especially during long operating periods, arises, so that the component parts which are referred to have to be inspected at regular intervals and, if necessary, exchanged/repaired.
In order to keep the wear of the affected component parts or machine components especially low in such situations, the machine components can be manufactured in a so-called clad design, wherein the regions which are especially affected by the anticipated wear or the anticipated contacts with adjacent components are covered with a protective lining which is also referred to as cladding. Such a cladding in this case can be formed from a cladding material which in comparison to the base material of the respective components has a greater mechanical hardness, so that by means of such a suitable material selection contact-induced wear which occurs can already be reduced.
On account of the greater hardness of the cladding material which is customary for such application purposes, however, it On account of the greater hardness of the cladding material which is customary for such application purposes, however, it is also more brittle than the respective base material of the base body of the machine component. A further treatment of the base body which is provided with the cladding material, for example by bending or suchlike, is now only possible to a limited extent as a result. Furthermore, during a thermal expansion of the base body, crack formations or other damage can develop in the region which is provided with the cladding material, on account of the different thermal expansion behavior. Particularly for use in thermally comparatively highly stressed regions, such as in the inner region of the combustion chamber of a gas turbine, such clad machine components are only conditionally suitable as a result.
SUMMARY OF INVENTION
The invention, therefore, is based on the object of disclosing a machine component of the aforementioned-type which is also especially suitable for use in a thermally comparatively highly stressed region of a driven machine. Furthermore, a gas turbine with a number of such machine components is to be disclosed.
With regard to the machine component, this object is achieved according to the invention as claimed in the claims.
The invention in this case starts from the consideration that the machine component for a basic applicability should be provided with a suitable cladding, subject to low-wear operating conditions. In order to avoid the disadvantages which accompany this, especially with regard to the possibility of further treatment and also stability in relation to thermal stress, the lateral expansion of the cladding should be kept especially low. However, in order to be able to cover an adequately large section of the surface in the process, individual zones of the cladding should be designed in a manner in which they are decoupled from each other, in order to enable in this way adequate flexibility with respect to thermal deformation and suchlike. For this purpose, the cladding should be designed in segmented fashion.
In this case, especially component parts or machine components which are positioned adjacent to each other can also be designed in such a clad manner, wherein the clad section of the surface of a first machine component is arranged adjacent to the clad section of the surface of a second machine component. The cladding material of the first machine component in this case has a different hardness than the cladding material of the second machine component. By suitable material selection, therefore, it is possible, in the case of contact occurring between the two machine components to purposefully focus the wear on one of the two machine components, specifically that with the cladding of lesser hardness, wherein for this purpose especially the more easily exchangeable or repairable machine component can be selected.
The cladding segments can be applied to the base body of the machine component by means of suitable techniques. The cladding segments, however, are advantageously applied to the base body by means of weld surfacing, so that an especially intimate connection to the base body and, consequently, a high stability of the machine component is altogether achieved.
The cladding segments can be applied to an outer surface of the base body so that the contour which results from this basically has a multiplicity of projections on the surface of the rail component, which are formed by means of the cladding segments. However, in order to enable required measurements to be adhered to or else the provision of an externally smooth surface for the component part or the machine component, the cladding segments are advantageously introduced into or embedded in each case in associated recesses in the base body. As a result, an almost even overall surface of the machine component is altogether advantageously achievable, wherein especially the outer surface of the cladding segments and the outer surface of the strips of the base body which extend between the cladding segments form a continuous surface.
Machine components of the type mentioned are advantageously used in a gas turbine, especially as a flame tube of a combustion chamber, as a mixing chamber of a burner, and/or as an inner casing of a combustion chamber.
The advantages which are achieved by the invention are especially that, by means of the segmented design of the cladding of the machine component, attachment of the cladding to the base body is enabled really for the first time even in the case of only small tolerance ranges, wherein a distortion of the base body as a result of the high working temperatures during the weld surfacing can be largely avoided especially with regard to the segmented design of the cladding. By means of the segmented design of the cladding, moreover, crack formation during the application of the cladding, which could occur during continuous welding of the cladding, is avoided. Moreover, subsequent bending of the component part is enabled without the cladding material being too heavily stressed in the process. Furthermore, deformations and connecting welds during assembly and in operation are comparatively simple to carry out without fear of critical effects on the component part.
By means of the attachment of the cladding segments in recesses which are incorporated in the base body, the surface of the machine component can be homogenized in retrospect, wherein a possible projection after the weld surfacing can also be subsequently removed. In this case, the meeting of externally predetermined measurements can be ensured, especially in the case of matched component part geometry. The segmented application of the cladding, moreover, reduces the stressing of the component part during manufacture, assembly, and in operation.
Particularly in the application in turbines, especially gas turbines, moreover, by means of suitable material selection in the pair-wise cladding of component pairs by suitable selection of different hardnesses, the wear can be focused on one of the two paired components, so that subsequent maintenance and exchange of affected components can be made considerably easier.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the invention is explained in detail based on a drawing. In the drawing:
FIG. 1 shows a longitudinal section through a gas turbine,
FIG. 2 shows a section through a combustion chamber in gas turbines, according to FIG. 1 , and
FIGS. 3 to 5 show machine components of the gas turbine in each case, according to FIG. 1 .
Like components in all the figures are provided with the same designations.
DETAILED DESCRIPTION OF INVENTION
The gas turbine 1 according to FIG. 1 has a compressor 2 for combustion air, a combustion chamber 4 and also a turbine 6 for driving the compressor 2 , and a generator, not shown, or a driven machine. For this purpose the turbine 6 and the compressor 2 are arranged on a common turbine shaft 8 , also referred to as a turbine rotor, to which the generator or the driven machine, as the case may be, is also connected, and which is rotatably mounted around its center axis 9 .
The combustion chamber 4 is equipped with a number of burners 10 for combusting a liquid or gaseous fuel. Furthermore, on its inner wall it is provided with heat shield elements, which are not shown in detail.
The turbine 6 has a number of rotor blades 12 which are rotatably connected to the turbine shaft 8 . The rotor blades 12 are arranged on the turbine shaft 8 in ring form and in this way form a number of rotor blade rows. Furthermore, the turbine 6 comprises a number of stationary stator blades 14 which are fastened on an inner casing 16 of the turbine 6 , similarly in ring form, forming stator blade rows. The rotor blades 12 in this case serve for driving the turbine shaft 8 by impulse transmission from a working medium M which flows through the turbine 6 . The stator blades 14 , however, serve for flow guiding of the working medium M between two rotor blade rows or rotor blade rings which are in series in each case when viewed in the flow direction of the working medium M. A pair in series, consisting of one ring of stator blades 14 or one stator blade row, and consisting of one ring of rotor blades 12 or one rotor blade row, in this case is also referred to as a turbine stage.
Each stator blade 14 has a platform 18 , which for fixing of the respective stator blade 14 on the inner casing 16 of the turbine 6 is arranged as a wall element. The platform 18 in this case is a thermally comparatively heavily stressed component part, which forms the outer boundary of a hot gas passage for the working medium M which flows through the turbine 6 . Each rotor blade 12 is fastened on the turbine shaft 8 in a similar fashion via a platform 20 which is referred to as a blade root.
Between the platforms 18 of the stator blades 14 of two adjacent stator blade rows, which platforms are arranged at a distance from each other, a guide ring 21 is arranged on the inner casing 16 of the turbine 6 in each case. The inner surface of each guide ring 21 in this case is also exposed to the hot working medium M which flows through the turbine 6 , and by means of a gap 24 is at a distance in the radial direction from the outer end 22 of the rotor blades 12 of a rotor blade row which lie opposite it.
As can be gathered from the enlarged view in FIG. 2 , each of the combustion chambers 4 in its inflow section, to which are connected a number of feed lines for media like fuel and combustion air, which are not specified in detail, is equipped in its interior with a so-called flame tube 30 , inside which the combustion of fuel takes place. Via a transition piece 34 , which is similarly arranged inside the casing 32 of the respective burner 10 and which is also referred to as a mixing chamber, the flame tube 30 on the outlet side is connected to a mixing chamber 34 of the combustion chamber 4 .
The flame tube 30 , the transition piece 34 and the inner casing 36 are interconnected in this case in the fashion of tubes which are fitted into each other, so that reliable media flow guiding from the flame tube 30 into the inner casing 36 of the combustion chamber 4 is ensured. The pipe ends which are fitted into each other in each case, subject to the predetermined measurements and tolerances, are positioned in this case as contact-free as possible from each other, so that wear on account of components which come into contact with each other and components which rub upon each other is avoided as far as possible. However, constantly recurring contact of these components with each other, which is operationally induced during operation of the gas turbine 1 , cannot be avoided, so that in any case a residual wear needs to be taken into account. In order to take this wear into account, a regular check and, if necessary, an exchange of these components is necessary within the scope of maintenance and inspection operations.
In order to keep the operational cost of the gas turbine 1 especially low and to largely simplify the necessary inspection and maintenance operations, the components of the gas turbine 1 are designed to be as wear-resistant as possible. In order to take into account in this case the wear which is induced by contact between the machine components, being the flame tube 30 , transition piece 34 and inner casing 36 , and particularly to keep this wear especially low during occurring contacts of the components with each other, the machine components which are referred to are designed as clad components. For this purpose, each of the machine components, being the flame tube 30 , transition piece 34 and inner casing 36 , is constructed from a base body 40 which is manufactured from base material and which in a section of its surface, which is shown in FIGS. 3 to 6 in each case, is provided with a cladding 42 consisting of a cladding material. The cladding material in this case is selected in such a way that it has a greater hardness in comparison to the base material, so that an increased resistance to mechanical and also thermal stress is given. The cladding material in this case is applied to the base body 40 in each case by means of weld surfacing.
In order to avoid an impairment of the manufacture, assembly and also operation of the respective machine components as a result of the cladding 42 , as it could occur, for example, as a result of the different thermal expansion behavior and crack formation associated with this during the actual welding process, or else during operation with increased thermal stress, the cladding 42 of the respective machine component is designed in segmented fashion. For this purpose, the cladding 42 comprises a plurality of cladding segments 44 , wherein the dimensioning with regard to the dimensioning of the actual machine component and the materials which are used is selected in such a way that, as a result of the laterally limited expansion of the respective cladding segment 44 , a too large impairment of the base body 40 by different thermal expansion behavior and suchlike is avoided.
As can be gathered from the view in FIG. 3 , the cladding segments 44 are introduced into associated recesses in the base body 40 in each case. The recesses in this case could have been made by suitable machining processes, such as by milling, turning or grinding. The dimensioning in this case can basically be undertaken in such a way that the cladding segments 44 are applied to a level surface of the base body 40 and recesses which correspond to their thickness are formed between them accordingly. During the attachment of the cladding segments 44 , the fabrication, however, as this is shown in FIGS. 3 to 6 , can also be carried out in such a way that the outer surface of the cladding segments 44 with the outer surface of the strips 46 of the base body 40 which extend between the outer cladding segments 44 form a continuous and therefore level surface. As a finished machine component in this case a component part results which with regard to its shaping, dimensioning and dimensional accuracy corresponds as far as possible to an originally provided component part, and especially has a correspondingly smooth and planar surface.
In FIG. 4 , it is shown that a curved cooling air ring 50 can also be designed as an at least partially clad machine component of the type which is referred to. The cooling air ring 50 in this case is also provided with cladding segments 44 on its surface, which are incorporated in corresponding recesses of the base body 40 which forms the cooling air ring 50 . In this case, cooling air passages 52 , which are formed by corresponding holes, are additionally also provided in the base body 40 of the cooling air ring 50 . By means of the forming-out of the recesses, which are also referred to as pockets, in which the cladding segments 44 are arranged in this case, the desired geometry of the cooling air ring 50 can be maintained. Nevertheless, when using the cladding segments 44 , an almost even surface and an even transition to the base body 40 is also created. As a result of this, an enhanced wear reduction and an improved binding between the materials which are used is ensured.
In FIG. 5 , it is shown that especially the transition piece 34 and the flame tube 30 of the gas turbine 1 in their overlapping region are designed as such clad machine components. Claddings 42 of these machine components are provided in this case on the surface segments which face each other in each case. In such an adjacent arrangement of two such clad machine components, moreover, as this is provided in the present case for the transition piece 34 and the flame tube 30 , a purposeful focusing of the wear on one of the two machine components, especially on the machine component which is more easily exchangeable, is enabled by means of a suitable material selection for the claddings 42 . For this purpose, it is specifically intended in the present case to select the cladding material for the cladding 42 of the flame tube 30 to be of lesser hardness than the material for the cladding 42 of the transition piece 34 .
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A machine component with a base body made of a base material, a part of the surface of which has been equipped with cladding material having a hardness greater in comparison to the base material. The cladding material is segmented and made up of a number of cladding segments that are spaced apart on the machine component. Each cladding segment may be disposed within a respective recess on the surface of the base body forming strips of the base body and material, and each such strip is disposed between consecutive segments forming a continuous surface.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is related to the following co-pending U.S. patent application filed on even date herewith, and incorporated herein by reference in its entirety:
Ser. No. 10______ (AUS920050812US1), entitled “METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR RECOVERY OF FORMATTING IN REPAIR OF BAD SECTORS IN DISK DRIVES”.
BACKGROUND OF THE INVENTION
[0003] 1. Technical Field
[0004] The present invention relates in general to data processing systems and in particular to flash memory within data processing systems. Still more particularly, the present invention relates to a system, method and computer program product for recovery of formatting in repair of bad sectors in flash memory of a data processing system.
[0005] 2. Description of the Related Art
[0006] Many microprocessor-based devices and systems use so-called “flash memory” devices, which employ a particular form of EEPROM (Electronically Erasable Programmable Read-Only Memory) to store data. Such devices can include, for example, computers, mobile telephones, electronic toys, cameras, and domestic appliances such as washing machines. Indeed, almost every microprocessor-based product in production today employs flash memory.
[0007] Flash memory maintains stored information without requiring a power source. Flash memory differs from typical EEPROM in that EEPROM erases its content one byte at a time, making a typical EEPROM slow to update. Flash memory can erase its data in entire blocks, making flash memory a preferable technology for applications that require frequent updating of large amounts of data, as in the case of a memory stick.
[0008] Inside a flash memory chip, information is stored in cells. A floating gate protects the data written in each cell. Tunneling electrons pass through a low conductive material to change the electronic charge of the gate in “a flash,” clearing the cell of its contents so that it can be rewritten. This “flash” for clearing cell contents is the basis of the ‘flash memory’ name.
[0009] Unfortunately, one of the largest contributors to the probability of failure for a device incorporating a flash memory is the flash memory itself. As flash memory components are usually soldered to other components such as a main circuit board, a flash memory failure will often result in the need to replace not only the flash memory, but other components as well. The degree to which flash memory has become deeply integrated into devices has caused device designers to create methods for correcting errors in flash memory, most of which depend on manual intervention by a user or on redundant storage of data.
[0010] In data processing systems, the formatting for data stored in a flash memory can become corrupted or damaged for a variety of reasons, for example, loss of power during a write or a format operation. As with the error correction methods for other problems in flash memory, prior art methods for recovering from corruption of this formatting data involve the constant maintenance of redundant copies of the data or require that the user corrects the corruption of the formatting through replacement or manual repair.
[0011] The state of prior art methods results in several drawbacks. First, maintaining redundant copies of formatting data is not desirable, because such maintenance increases storage requirements. This concern about storage requirements becomes particularly important in embedded systems or other systems in which storage resources are limited. Similarly, prior art methods that require the user to correct the corruption of the formatting through replacement or manual repair involve time costs to the user or information technology personnel. The reduction of such costs is desired.
SUMMARY OF THE INVENTION
[0012] A method for correcting a formatting error in a flash memory is disclosed. An error in a first formatting of a first flash memory is discovered, and a second formatting is extracted from a second flash memory storing second data. The erroneous first formatting is replaced with a modification of the second formatting, and first data is stored in the first flash memory with the modification of the second formatting. The first data is different from the second data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed descriptions of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0014] FIG. 1A depicts a block diagram of a data processing system in which a preferred embodiment of the method, system and computer program product for recovery of formatting for repair of bad sectors in flash memory attached to a data processing system is implemented;
[0015] FIG. 1B depicts flash memory attached to a data processing system in accordance with a preferred embodiment of the present invention;
[0016] FIG. 2 illustrates a high-level logical flowchart of a method for reading and writing data, which includes performing recovery of formatting in repair of bad sectors in flash memory attached to a data processing system in accordance with a preferred embodiment of the present invention; and
[0017] FIG. 3 depicts a high-level logical flowchart of a method for performing recovery of formatting in repair of bad sectors in flash memory attached to a data processing system in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The present invention takes advantage of a dual media image design, in which similar copies of formatting data, also called critical data, exist in different sectors in a flash memory or within multiple units of flash memory. If and when an interruption to an operation touching formatting data causes corruption of a sector of formatting data, the present invention detects the corruption and utilizes a similarly formatted sector as a template to reconstruct the corrupted formatting. The reconstructed formatting is then used to repair the corrupted sector, allowing the system to return to full capability and function without alerting the user to the corruption. The present invention provides a solution to data corruption without requiring specific redundant copies of formatting data or requiring user intervention.
[0019] With reference now to figures and in particular with reference to FIG. 1A , there is depicted a data processing system 100 that may be utilized to implement the method, system and computer program product of the present invention. For discussion purposes, the data processing system is described herein as having features common to a server computer. However, as used herein, the term “data processing system,” is intended to include any type of computing device or machine that is capable of receiving, storing and running a software product, including not only computer systems, but also devices such as communication devices (e.g., routers, switches, pagers, telephones, electronic books, electronic magazines and newspapers, etc.), data storage devices, and personal and consumer electronics devices (e.g., handheld computers, Web-enabled televisions, home automation systems, multimedia viewing systems, etc.).
[0020] FIG. 1A and the following discussion are intended to provide a brief, general description of an exemplary data processing system adapted to implement the present invention. While parts of the invention will be described in the general context of instructions residing as firmware within ROM within a server computer, those skilled in the art will recognize that the invention also may be implemented in a combination of program modules running in an operating system. Generally, program modules include routines, programs, components and data structures, which perform particular tasks or implement particular abstract data types. 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 memory storage devices.
[0021] Data processing system 100 includes one or more processing units 102 a - 102 d , at least two units of flash memory 104 a - 104 b coupled to a memory controller 105 , at least one unit of RAM 111 coupled to memory controller 105 , and a system interconnect fabric 106 that couples memory controller 105 to processing unit(s) 102 a - 102 d and other components of data processing system 100 . Commands on system interconnect fabric 106 are communicated to various system components under the control of bus arbiter 108 .
[0022] Data processing system 100 further includes additional non-volatile bulk storage media, such as a first hard disk drive 110 and a second hard disk drive 112 . First hard disk drive 110 and second hard disk drive 112 are communicatively coupled to system interconnect fabric 106 by an input-output (I/O) interface 114 . Although hard disks are described above, it should be appreciated by those skilled in the art that other types of media which are readable by a computer, such as a removable magnetic disks, CD-ROM disks, magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, and other later-developed hardware, may also be used to provide non-volatile bulk data storage in the exemplary computer operating environment. Additional non-volatile storage is provided in ROM 107 , which contains firmware 109 for performing various essential system operations. The present invention is performed using instructions stored as firmware 109 within ROM 107 and is illustrated with respect to two units of flash memory 104 a - 104 b coupled to a memory controller 105 , which contains a memory unit called a formatting modification storage unit 180 . The present invention is also applicable to first hard disk drive 110 and second hard disk drive 112 and a wide range of other media that employ dual media image design.
[0023] Data processing system 100 may operate in a networked environment using logical connections to one or more remote computers, such as remote computer 116 . Remote computer 116 may be a server, a router, a peer device or other common network node, and typically includes many or all of the elements described relative to data processing system 100 . In a networked environment, program modules employed by data processing system 100 , or portions thereof, may be stored in a remote memory storage device, such as remote computer 116 . The logical connections depicted in FIG. 1A include connections over a local area network (LAN) 118 , but, in alternative embodiments, may include a wide area network (WAN).
[0024] When used in a LAN networking environment, data processing system 100 is connected to LAN 118 through an input/output interface, such as a network adapter 120 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
[0025] Referring now to FIG. 1B , flash memory attached to a data processing system in accordance with a preferred embodiment of the present invention is illustrated. Flash memory 104 a contains four sectors 152 a - 158 a . Sector 152 a contains a header 160 a , a partition table offset 162 a , partition names 164 a and a partition table size 166 a , which are collectively referred to as formatting data 160 a - 166 a , while sectors 154 a - 158 a contain stored data, such as that data used by applications. Flash memory 104 b contains four sectors 152 b - 158 b . Sector 152 b contains a header 160 b , a partition table offset 162 b , partition names 164 b and a partition table size 166 b , which are collectively referred to as formatting data 160 b - 166 b , while sectors 154 b - 158 b contain stored data, such as that data used by applications. Thus, sectors 154 a - 158 a of flash memory 104 a may (and usually do) contain first data different from the second data within sectors 154 b - 158 b of flash memory 104 b.
[0026] Turning now to FIG. 2 , a high-level logical flowchart of a method for reading and writing data, which includes performing recovery of formatting for repair of bad sectors in storage systems attached to a data processing system in accordance with a preferred embodiment of the present invention is illustrated.
[0027] For illustrative purposes, the exemplary discussion of FIG. 2 and FIG. 3 contained herein will refer to a format operation being performed on flash memory 104 a , with flash memory 104 b to provide backup format data. One skilled in the art will quickly realize that either of flash memory 104 a and flash memory 104 b may provide backup to the other during format operations. The process starts at step 200 , and then proceeds to step 204 , which depicts memory controller 105 beginning a critical operation to a format sector 152 a of storage within flash memory 104 a . The process next moves to step 206 . At step 206 , memory controller 105 reads sector 152 a of flash memory 104 a . The process then proceeds to step 208 , which illustrates memory controller 105 updating a local copy of the data contained in the sector 152 a of flash memory 104 a read in step 206 . The process next moves to step 210 .
[0028] At step 210 , memory controller 105 erases the sector 152 a of flash memory 104 a read in step 206 . The process then proceeds to step 212 . At step 212 , memory controller 105 performs verification and recovery functions on the formatting data 160 a - 166 a of sector 152 a read in step 206 . The verification and recovery functions of step 212 are detailed below with respect to FIG. 3 . The process next moves to step 214 . At step 214 , memory controller 105 rewrites the sector 152 a of flash memory 104 a read in step 206 . The process then ends at step 216 .
[0029] Referring now to FIG. 3 , a high-level logical flowchart of a method for performing recovery of formatting for repair of bad sectors in flash memory systems attached to a data processing system in accordance with a preferred embodiment of the present invention is depicted. The process starts at step 300 and then moves to step 302 , which illustrates memory controller 105 verifying the header 160 a of the sector 152 a of flash memory 104 a read in step 206 . The process then proceeds to step 304 . At step 304 , memory controller 105 determines whether the verification of the header 160 a of the sector 152 a of flash memory 104 a read in step 206 succeeded. If the verification of the header 160 a of the sector 152 a of flash memory 104 a read in step 206 did not succeed, then the process moves to step 306 .
[0030] Steps 306 - 316 represent a generalized recovery process, which is used in response to the determination of a failure of a verification at any of step 304 and steps 318 - 328 (which are explained below). At step 306 , memory controller 105 asserts an internal flag bit indicating a verification failure. The process next proceeds to step 308 , which illustrates memory controller 105 copying a binary image of a sector 152 b of flash memory 104 b , which is similar to the sector 152 a of flash memory 104 a read in step 206 , to a formatting modification storage unit 180 in memory controller 105 . The process then moves to step 310 , which depicts memory controller 105 reading the formatting data 160 b - 166 b from the binary image in formatting modification storage unit 180 of sector 152 b of flash memory 104 b . The process next proceeds to step 312 . At step 312 , memory controller 105 modifies, to the extent necessary, the formatting data 160 b - 166 b from the binary image in formatting modification storage unit 180 of sector 152 b of flash memory 104 b for use as a replacement for the corrupted formatting data 160 a - 166 a of sector 152 a of flash memory 104 a read in step 206 .
[0031] The necessary modifications will vary with particular embodiments of the present invention and on the basis of differences between the particular type of flash memory used and the particular data stored in sectors 154 a - 158 a of flash memory 104 a and in sectors 154 b - 158 b of flash memory 104 b . In a preferred embodiment, some data from formatting data 160 b - 166 b is capable of direct reuse. For instance, data extracted from header 160 b is directly reusable in header 160 a . Likewise, partition table offset 162 b is directly reusable as partition table offset 162 a and partition table size 166 b is directly reusable as partition table size 166 a.
[0032] In a preferred embodiment, partition names 164 a will be derived by changing the trailing digit of partition names 164 b to correspond to a designator identifying the flash memory 104 a in which they exist. A preferred embodiment contains flash memory 104 b , which is designated by convention as ‘flash memory 2 ’ with partition names boot 2 , kern 2 , dump 2 and user 2 . A preferred embodiment also contains flash memory 104 a , which is designated by convention as ‘flash memory 1 ’. When modifying partition names 164 b for use as partition names 164 a , memory controller 105 will create partition names boot 1 , kern 1 , dump 1 and user 1 .
[0033] In alternative embodiments, other formatting data 160 b - 166 b , such as partition names 164 a will be derived from a scan of the sectors 154 a - 158 a of flash memory 104 a . Following block 312 , the process then moves to step 314 , which illustrates memory controller 105 updating the sector 152 a of flash memory 104 a read in step 206 with the formatting created in step 312 for use as a replacement for the corrupted formatting data 160 a - 166 a formerly present in the sector 152 a of flash memory 104 a read in step 206 . The process then ends at step 316 .
[0034] Returning to the verification process at step 304 , if the verification of the header 160 a of sector 152 a of flash memory 104 a read in step 206 succeeded, then the process moves to step 318 , which depicts memory controller 105 verifying partition offset table 162 a of sector 152 a of flash memory 104 a read in step 206 . The process next moves 320 . At step 320 , memory controller 105 determines whether verification of partition offset table 162 a of sector 152 a of flash memory 104 a read in step 206 succeeded. If memory controller 105 determines that verification of partition offset table 162 a of sector 152 a of flash memory 104 a read in step 206 did not succeed, then the process moves to step 306 , which is described above. If memory controller 105 determines that verification of partition offset table 162 a of sector 152 a of flash memory 104 a read in step 206 succeeded, then the process proceeds to step 322 . At step 322 , memory controller 105 verifies the validity of various partition names 164 a in the sector 152 a of flash memory 104 a read in step 206 .
[0035] The process then proceeds to step 324 , which depicts memory controller 105 determining whether verification of the validity of partition names 164 a in sector 152 a of flash memory 104 a read in step 206 succeeded. If verification of the validity of partition names 164 a in sector 152 a of flash memory 104 a read in step 206 did not succeed, then the process moves to step 306 , which is described above. If verification of the validity of partition names 164 a in sector 152 a of flash memory 104 a read in step 206 succeeded, then the process moves to step 326 , which illustrates memory controller 105 verifying partition table size 166 a of sector 152 a of flash memory 104 a read in step 206 . The process then moves to step 328 . At step 328 , memory controller 105 determines whether verification of partition table size 166 a of sector 152 a of flash memory 104 a read in step 206 succeeded. If, verification of partition table size 166 a of sector 152 a of flash memory 104 a read in step 206 did not succeed, then the process moves to step 306 , which is described above. If verification of partition table size 166 a of sector 152 a of flash memory 104 a read in step 206 succeeded, then the process ends at step 316 .
[0036] As shown with respect to flash memory 104 a and flash memory 104 b , the present invention takes advantage of a dual media image design, in which similar copies of formatting data, also called critical data, exist in different sectors 152 a and 152 b in a flash memory or within multiple units of flash memory. If and when an interruption to an operation touching formatting data 160 a - 166 a causes corruption of a sector 152 a of formatting data 160 a - 166 a , the present invention detects the corruption and utilizes a similarly formatted sector 152 b as a template to reconstruct the corrupted formatting data 160 a - 166 a . The reconstructed formatting is then used to repair the corrupted sector 152 a , allowing the system to return to full capability and function without alerting the user to the corruption.
[0037] While the invention has been particularly shown as described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. It is also important to note that although the present invention has been described in the context of a fully functional computer system, those skilled in the art will appreciate that the mechanisms of the present invention are capable of being distributed as a program product in a variety of forms, and that the present invention applies equally regardless of the particular type of signal bearing media utilized to actually carry out the distribution. Examples of signal bearing media include, without limitation, recordable type media such as floppy disks or CD ROMs and transmission type media such as analog or digital communication links.
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A method for correcting a formatting error in a flash memory is disclosed. An error in a first formatting of a first flash memory is discovered, and a second formatting is extracted from a second flash memory storing second data. The erroneous first formatting is replaced with a modification of the second formatting, and first data is stored in the first flash memory with the modification of the second formatting. The first data is different from the second data.
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BACKGROUND OF THE INVENTION
The invention relates to a device for preventing skidding and for increasing the grip of vehicle wheels on ice and snow.
In addition to snow chains winter tires, also called adhesive tyres, are used for motor vehicles when travelling on snow-covered steep up and down gradients. Snow chains are not well liked because they are often difficult to fix to the vehicle tires and because they must be used in such a way that the road is not damaged, i.e. they must be removed on dry sections of the road following snow or ice-covered sections of the road. In addition, when travelling on dry roads snow chains are subject to a high degree of wear and also do not permit travel at high speed. In particular when roads become covered with ice at short notice, e.g. ice surfaces produced by drizzle falling on frozen road coverings it is hardly possible to use snow chains and winter tyres. Tyres covered with spikes are also not always usable.
In addition to snow chains and winter tyres starting aids are known, but these are not a substitute for snow chains and winter tyres. These starting aids, which merely comprise clamp straps fitted to the tyres, merely serve to permit a vehicle to be driven a short distance out of mud or snow.
BRIEF SUMMARY OF THE INVENTION
The problem of the present invention is therefore to provide a device which can be fitted to motor vehicle tyres and which can be used for preventing skidding and for increasing the grip of vehicle wheels on ice and snow, which can be used without difficulty whenever needed, which can be easily fitted to any vehicle wheel, whose manufacture is economic and permits higher speeds than when driving with snow chains or spiked tyres and which is much more effective than winter tires.
According to the invention this problem is solved by a device which permits skidding and increases the grip of vehicle wheels on ice and snow, wherein it comprises a hub cap-like and disc-like casing connected in fixed or detachable manner with the wheel rim with at least two anti-skid arms made from resilient-elastic materials, such as spring steel or the like arranged in said casing, whereby in the position of use the anti-skid arms radially and with their end portions in the tread area of the tyre are constructed so as to fixedly engage round the latter in its circumferential area in a zonal manner adapting to the rolling shape of the tire or constructed so as to be swung in or out by means of mechanical, pneumatic, hydraulic, electromotive operating mechanisms or the like, their ends being provided externally with a gripping profile.
The casing which can be fixed or fixedly connected to the wheel rim comprises a base disc which can be fixed to the wheel rim, carries a disc which is rotatable about its centre and keeps said disc at a distance accompanied by the formation of a gap-like space, whereby in said space and adjacent to its rotary edge the base disc has at least two anti-skid arms arranged at a uniform spacing from one another, which are pivotable in the vicinity of their articulation ends and projecting over the tire profile from the outer tire side in the swung out state, each anti-skid arm being made from spring steel and can be swung out from a tangential initial position into a radial position by means of a pivoted lever in the case of a manual or automatic rotation of the rotating disc in such a way that the free end of the anti-skid arms comes to rest between the tyre tread and its rolling surface, whereby each pivoted lever of the number of pivoted levers which corresponds to the number of anti-skid arms is articulated by one of its two ends to the rotating disc adjacent to its rotary edge, whilst the other end of the pivoted lever is connected in crank mechanism-like manner with the anti-skid arm for the purpose of the engagement of the gripping arms on the vehicle tire in the operating position, whilst the rotating disc which is rotatable by means of an operating mechanism is held in the pivoted out position of the anti-skid arm by means of a fixing and arresting device and can be automatically rotated back to the initial position by means of tension springs.
As a result of the device according to the invention a skid protection is obtained for vehicle wheels, together with improved grip of the wheels on ice and snow. Due to the fact that at least two radially directed anti-skid arms made from spring strip steel project from the outer side of the tire over the tire profile on rotating the tire the ends of the said arms come to rest between the tire profile and the rolling surface, such as the road or other substrate. To further increase grip the ends of the anti-skid arms are externally provided with a gripping profile which can also be in the form of spikes. It is easy to fit the anti-skid device because it is merely necessary to fit the disc-like casing to the rim and on operating the rotating disc the anti-skid arms are swung out of the inner area of the casing and engage elastically on the tire. In addition to a manual operation by means of a crank for the rotation of the rotating disc of the casing the swinging out of the anti-skid arms, which in the swung out position assume a half U-shape, there can also be a fully automatic swinging out of the anti-skid arms by means of corresponding actuating and drive mechanisms operable by means of a switch on the vehicle dashboard. The anti-skid arms can also be retracted in the same way. If in the extended state of the anti-skid arms the rotating disc is under spring tension, then only the fixing and arresting device for the rotating disc provided on the anti-skid device is operated, so that due to the spring tension the rotating disc is rotated and the anti-skid arms are swung in. On rotating the rotating disc the pivoted levers connected to the anti-skid arms bring about the swinging in and out of said arms, whereby the pivoted levers simultaneously bring about an application of the anti-skid arms to the tire profile with the arms in the swung out state.
Manufacture of the anti-skid device is inexpensive because it comprises few parts. If the anti-skid arms are swung in they do not form a hindrance when driving. The travelling behaviour is in no way impaired. When the anti-skid arms are swung out it is still possible to drive at high speed. During positioning and construction the anti-skid arms automatically adapt to the pressing movements of the tire. The anti-skid device permits quiet running and is neither prejudicial to the vehicle nor to the road. It takes up little space and can be constructed for most standard rims without rim changes being necessary.
Advantageous further developments of the invention can be gathered from the Subclaims.
According to a further development of the anti-skid device a manual operating mechanism for the rotating disc is provided which comprises an insertion opening in the rotating disc for a gear crank and a pitch circle rack in the area of the opening on the base disc, whereby the gear crank 82 has in its end area which passes through the opening a toothed gear which engages in the pitch circle rack. This operating device permits an effortless manual swinging out of the anti-skid arms.
An automatic swinging out of the anti-skid arms is made possible by an operating device for the rotating disc comprising a pitch circle-like rack arranged on the wall surface of the rotating disc facing the base disc and located in the space between the rotating disc and the base disc, said rack being in engagement with a toothed gear which passes through an opening provided in the base disc in the vicinity of the rack and connected to a drive mechanism fixedly connected to the wheel suspension.
According to a further embodiment of the invention the rotating disc can automatically be rotated from the swung out position of the anti-skid arms into its initial position.
For the purpose of securing the rotating disc with the anti-skid arms swung outwards a fixing and arresting device is provided, which is operable on the one hand manually and on the other by means of a correspondingly controlled drive mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplified and non-limitative embodiments of the invention are described hereinafter relative to the drawings, wherein show:
FIG. 1 a plan view of a vehicle tire with an anti-skid device with swung in anti-skid arms arranged on the rim.
FIG. 2 a plan view of a vehicle tire with an anti-skid device with swung out anti-skid arms arranged on the rim.
FIG. 3 a vehicle tire in a partial view with anti-skid arms in various positions.
FIG. 4 the anti-skid device comprising a rotating disc and a base disc with a manually operable rotating disc operating mechanism, partly in partial view and partly in vertical section.
FIG. 5 the anti-skid device comprising a rotating disc and a base disc with an automatic rotating disc operating mechanism, partly in partial section and partly in vertical section.
FIG. 6 the anti-skid device with the rotating disc fixing and arresting device, partly in partial section and partly in vertical section.
FIG. 7 a tire anti-skid device fixed to the wheel rim with an unloaded and a loaded tyre, partly in elevation and partly in vertical section.
FIG. 8 a tire anti-skid device detachably connected to a rim and constructed as a component, in the case of an unloaded and a loaded tyre, partly in elevation and partly in vertical section.
FIG. 9 an anti-skid arm with a profile body in a view of the surface facing the tire tread.
FIG. 10 a side view of the anti-skid arm of FIG. 9.
FIG. 11 a further embodiment of an anti-skid arm with a profile body in a view of the surface facing the tire tread.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As can be gathered from FIGS. 1 and 2 the anti-skid device 10 according to the invention comprises a casing 15 receiving anti-skid arms 41, 42, 43, 44, 45 and 46 which can be swung in and out and which is fixed to the rim 11 of a vehicle wheel 13. Rim 11 is provided with a brake part 12 (FIG. 7). The tread area of tyre 13 is designated by 14.
Casing 15 constructed in hub cap-like and disc-like manner comprises a circular base disc 20 and a rotating disc 30 which is rotatable about the centre of said base disc. Base disc 20 is fixed to rim 11 (FIG. 7). Base disc 20 can have a profile corresponding to the side face profile of the rim.
Rotating disc 30, which is held on base disc 20 by means of guides or the like and is rotatable in the direction of arrows X and X1 (FIG. 3) is constructed in cap-like manner and has a circulating, downwardly bent edge portion 33. In the centre rotating disc 30 has a circular opening 39 and a circulating edge portion 33 bent downwards in the direction of base disc 20 and bent downwards on the circulating edge 39a of opening 39 (FIG. 7). Rotating disc 30 is mounted on base disc 20, so that a gap-like space 35 is formed between rotating disc 30 and base disc 20. The inner wall surface of the rotating disc 30 which faces base disc 20 is designated as 32. The circulating downwardly bent edge portion 33 on rotating disc 30 is not formed in the area of the circulating edge 30a thereof, but adjacent to its centre 31, as can be gathered from FIGS. 7 and 8. The rotating disc 30 has a portion which projects beyond the circulating, downwardly bent rotating disc portion 33.
For the reliable guidance of rotating disc 30 on base disc 20, provided with openings for screwing the latter to rim 11, rotating disc 30 is guided on base disc 20 by means of a ball or roller bearing 37. For the purpose of receiving the ball or roller bearing 37 the circulating edge of the downwardly bent portion 33 of rotating disc 30 has a circulating groove or a plurality of grooves 36 facing a circulating recess or recessed portions 26 on base disc 20. The balls or rollers of the ball or roller bearing 37 are arranged in the inner space formed by the circulating groove 36 and the circulating recess 26. However the possibility also exists of providing rotating disc 30 in the area of its circulating edge 30a with the downwardly bent portion 33, so that a closed housing is formed with base disc 20. Corresponding openings are then provided in the circulating downwardly bent portion 33 for the extension and retraction of the anti-skid arms 41 to 46. The grooved portions 36 and the recessed portions 26 are preferably provided in the swung in area of the pivoted levers.
As can be gathered from FIGS. 1 and 2 six anti-skid arms 41 to 46 are provided in the casing in the present embodiment. However, the number of anti-skid arms can be selected at random. However, there must be at least two anti-skid arms. All anti-skid arms have the same relative spacing.
The end 41a, 42a, 43a, 44a, 45a and 46a of each individual anti-skid arm 41 to 46 is articulated to the base disc 20 at 21, 22, 23, 24, 25 and 26. The articulation points 21 to 26 are provided in the vicinity of the circulating edge of the base disc.
In order to be able to swing the anti-skid arms 41 to 46 about articulation points 21 to 26 pivoted levers 51, 52, 53, 54, 55 and 56 connected to the anti-skid arms 41 to 46 are provided. Each anti-skid arm is connected in crank mechanism-like manner with a pivoted lever. The end 51a, 52a, 53a, 54a, 55a and 56a of each pivoted lever 51 to 56 is fixed to the rotating disc 30 in the vicinity of its rotating edge 30a at 61, 62, 63, 64, 65 and 66 (FIG. 2). The in each case other pivoted lever end 51b, 52b, 53b, 54b, 55b and 56b is articulated at 71, 72, 73, 74, 75 and 76 to the anti-skid arm 41 to 46, so that the latter and the pivoted levers 51 to 56 assume the position shown in FIG. 1 with the anti-skid arms in the swung in position. If, however, rotating disc 30 is pivoted in the direction of arrow X1 (FIG. 3), anti-skid arms 41 to 46 are swung out of casing 15 by means of pivoted levers 51 to 56 and assume the position shown in FIG. 2.
The swinging in and out of anti-skid arms 41 to 46 is demonstrated in FIG. 3 relative to anti-skid arm 41 and the associated pivoted lever 51. In position A the anti-skid arm and the pivoted lever assume a swung in position. If the rotating disc 30 is rotated in the direction of arrow X1, the anti-skid arm 41 is pivoted beyond position B into the swung out position C, so that anti-skid arm 41 comes to rest laterally alongside tyre 13 and by its free end 41b zonally engages over the tread 14 of tyre 13 (FIGS. 7 and 8). In order to prevent in the case of a rotation of rotating disc 30 in direction X1 that the anti-skid arms 41 to 46 pass beyond radial position C, each anti-skid arm has a stop member 27 at its end 41a to 46a. So that said stop member 27 is fully effective each anti-skid arm 41 to 46 is constructed as a two-armed lever, as shown in FIG. 3. Portion 41c extended beyond articulation point 21 then carries the stop member 27. All the other anti-skid arms are constructed in the same way as anti-skid arm 41. In the swung out position the anti-skid arms 41 to 46 engage by means of their free ends 41b, 42b, 43b, 44b, 45b and 46b over the tread 14 of tire 13 (FIG. 2).
Each anti-skid arm 41 to 46 is made from a resilient-elastic material, such as for example spring steel, so that in addition to an adequate inherent elasticity it is also possible to bend down the free end portion 41b to 46b of each anti-skid arm 41 to 46 in the area of the tread 14 of the tire 13 by means of pivoted lever 51 to 56 so that the anti-skid arms can also be swung into the casing 15, because as a result of the resilient-elastic construction of the arms the latter can spring or deform back from the downwardly bent shape in the position of use into a rectilinear and planar shape on reaching the position of non-use.
In order to achieve this deformation of the anti-skid arms 41 to 46 in their end areas 41b to 46b, pivoted levers 51 to 56 are under a great initial tension, i.e. their length is made such that in the swung out state of the anti-skid levers 41 to 46 the latter assume the tyre deformation positions shown at A and B in FIGS. 7 and 8.
However, it is also possible to preshape the anti-skid arms 41 to 46, so that they have from the outset a slightly downwardly bent end position and consequently the anti-skid arms ends come to rest in the vicinity of tire tread 14 when the anti-skid arms 41 to 46 are extended. Due to the use of spring steel preshaped in this way it is possible to pivot back the arms into the casing 15, whereby they then assume an elongated shape. If the anti-skid arms are then swung out again they are deformed into an arcuate shape due to the resilience of the spring steel used.
It is also possible to use materials other than spring steel, so that pivoted levers 51 to 56 can also be made from spring wire or corresponding suitable synthetic materials.
The anti-skid arms 41 to 46 are detachably articulated to base disc 20, so that damaged or worn arms can be changed effortlessly.
At free ends 41b to 46b the anti-skid arms 41 to 46 have externally gripping profiles 40, so that an excellent grip is obtained. The gripping profile 40 shown in FIG. 7 may may be constructed as spikes.
The rotating disc is provided with an operating mechanism 80 for the manual rotation thereof for the purpose of swinging in or out the anti-skid arms 41 to 46. According to FIGS. 3 and 4 the operating mechanism 80 has an insertion opening 81 in rotating disc 30 into which can be inserted a gear crank 82. In the vicinity of insertion opening 81 base disc 20 is provided with a pitch circle rack 83 fixed to a toothed gear 84 at the free end of the gear crank portion inserted through opening 81. If gear crank 82 is passed through opening 81, so that gear 84 engages with the pitch circle rack 83 rotating disc 30 can be rotated in the direction of arrow X or X1 in the case of a corresponding operation of gear crank 82 (FIG. 3).
FIGS. 5 and 8 show an automatic operating mechanism 80. In this embodiment the pitch circle rack 83 is arranged on the inner wall surface 32 of rotating disc 30. Rack 83 engages with toothed gear 85, mounted at 87 on base disc 20 and which by means of one portion engages through an opening 28 in base disc 20. Gear 85 is driven by means of a drive mechanism. The drive can be of an electromotive type, but other drives are possible. By means of the drive mechanism rotating disc 30 can be rotated in the direction of arrow X or X1.
Tension springs 100 permit an automatic return of rotating disc 30 from the swung out position of the anti-skid arms into the swung in position thereof. These tension springs 100 are distributed over the circumference of rotating disc 30 and/or base disc 20 in such a way that each spring 100 is fixed by its one end 101 to rotating disc 30 and by its other end 102 to base disc 20 (FIG. 6). If rotating disc 30 has a position in which the anti-skid arms 41 to 46 are swung in, tension springs 100 are not under tension. If by means of gear crank 82 or drive mechanism 86 rotating disc 30 is rotated in the direction of arrow X1, so that the anti-skid arms 41 to 46 are swung out springs 100 are tensioned and attempt to spring back into their initial position, thereby rotating back rotating disc 30. To prevent an automatic rotating back of rotating disc 30 into its initial position a fixing and arresting device 90 is provided in casing 15. Device 90 comprises a stop cam 91 shaped onto the inner wall surface 32 of rotating disc 30 and a two-armed stop lever 92 pivotably mounted on base disc 20 at 93. In position A of FIG. 6 this two-armed stop lever 92 prevents a backward rotation of rotating disc 30 by acting on the stop cam 91. If, however, stop lever 92 is moved into position B, stop cam 91 is released from stop lever end 92a, so that tension springs 100 rotate rotating disc 30 in the direction of arrow X until the anti-skid arms 41 to 46 are pivoted into the casing. Stop lever 92 can be actuated by mechanical (structual tension), pneumatic, hydraulic or electromagnetic devices, indicated at 94 in FIG. 6. This automatic control mechanism 94 is in working connection with the other stop lever end 92b. It is also possible to use an operating mechanism 94, which is transmitter-controlled.
Casing 15 with base disc 20, rotating disc 30 and anti-skid arms 41 to 46, as well as pivoted levers 51 to 56 can be constructed as a single unit, which is then fixed to rim 11 using wheel nuts as indicated in FIG. 8. It is also possible for fixing to take place by means of cover plates to the rim openings. The construction of FIG. 8 permits a subsequent fitting of the anti-skid device according to the invention to commercial rims. In this case the operating mechanism 94 for returning the rotating disc 30 is connected by means of a feedline 95 with a switching mechanism arranged on a vehicle dashboard, so that it is possible to operate rotating disc 30 from inside the vehicle, thereby giving the possibility of retracting the anti-skid arms 41 to 46 at any time. The anti-skid device is fixed to rim 11 by means of base disc 20 mounted on the screws on rim 11 and tightened by means of wheel nuts.
In the embodiment of FIG. 7 the anti-skid device forms an integrated part of the rim and namely in such a way that base disc 20 simultaneously constitutes the front rim disc. Rotating disc 30 is then held and rotated in rotary manner on the rim which is constructed as a base disc.
The outside of rotating disc 30 can be constructed as a decorative cap.
Due to the resilient-elastic construction of each anti-skid arm 41 to 46 the end areas thereof adapt to the particular tyre profile, independently of the deformation of the tyre. FIGS. 7 and 8 show at A the deformation of the anti-skid arm in the case of an unloaded tire, with at B the adaptation thereof in the case of a loaded tire. Furthermore the end position of each anti-skid arm 41 to 46 is limited by means of stop cams 38 provided on rotating disc 30 (FIG. 2).
In order to obtain the adhesion between anti-skid arms 41 to 46 and the tyre tread the end area of the arms facing the tread is provided with a figuring or profiling 200 (FIGS. 9 to 11), extending over the entire length of the engagement surface of each anti-skid arm with the tyre tread and the tire sidewall, is made from rubber or synthetic materials and is in the form of profile bodies 201. The latter can be constructed as raised ribs running at right angles to the longitudinal direction of the anti-skid arm and are fitted to the latter (FIGS. 9 and 10). Furthermore profile sections 201a can be attached to the anti-skid arms 41 to 46 in such a way that they engage in the tire profile, i.e. into the profile grooves of said profile, so that the anti-skid arms are secured to the tire when said arms are in the operating position. The latter embodiment is particularly advantageous in the case of tires with large post profiles, such as e.g. winter tires.
The invention is not limited to the embodiments described and represented hereinbefore and various modifications can be made thereto without passing beyond the scope of the invention.
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The invention relates to an anti-skid device for vehicle wheels for travelling on ice and snow with a disc-like casing connected to the wheel rim with resilient-elastic anti-skid arms, constructed in such a way that in the position of use their ends can be swung out radially into the tire tread area while adapting to the rolling shapes of the tire and can be swung in when not in use, so that a device is obtained which can effortlessly be fitted whenever required, which is inexpensive to manufacture and which permits higher speeds than are possible when travelling with snow chains or spiked tires.
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INCORPORATION BY REFERENCE
The disclosure of Japanese Patent Application No. 2003-318789 filed on Sep. 10, 2003, including its specification, drawings and abstract, is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an injection molding technique for injecting a resin material into a cavity to form an injection molded product. More particularly, the invention relates to a technique that pressurizes a die so as to restrain generation of burr in the molded product formed through the injection molding method.
2. Description of Related Art
A generally employed injection molding apparatus is provided with a clamp mechanism including a hydraulic stuffer or a toggle mechanism for the purpose of maintaining the resin pressure within the cavity constant and restraining deformation of the die. The clamp mechanism serves to clamp a fixed mold and a moveable mold.
There is a known mechanism disclosed in Japanese Patent Publication No. JP-B-6-67582, which pressurizes a die in the direction perpendicular to a die clamping direction in conjunction with a die clamp mechanism so as to restrain deformation of the die caused under the resin pressure without requiring enhancement of rigidity of the die and forming a molded product with high accuracy through an injection molding method at a low cost.
There is also a known apparatus disclosed in Japanese Patent Publication No. JP-B-6-28886, which employs a hydraulic cylinder as the mechanism that pressurizes a die in the direction perpendicular to a die clamping direction.
The generally employed mechanism that pressurizes the die in the direction perpendicular to the die clamping direction requires a pressing unit to be provided for the injection molding apparatus, resulting in increase in both the cost and the system size. The aforementioned mechanism fails to completely prevent generation of burr in the injection molded product.
The technique disclosed in Japanese Patent Publication No. JP-B-6-67582 cannot be realized by a simple structure, and it is difficult to control the pressing force applied to the die in the direction perpendicular to the die clamping direction in accordance with the resin pressure.
The technique disclosed in Japanese Patent Publication No. JP-B-6-28886 may increase the size of the system and elongate the time required for the molding method. Accordingly the control of the injection molding apparatus becomes complicated.
SUMMARY OF THE INVENTION
In the invention, a frame structure may be detachably attached to the die on each of the respective outer surfaces of the fixed mold and the moveable mold of the injection molding apparatus. The frame structure is provided with a pressurizing mechanism, and includes frames that can be combined so as to be attached to the die. The die is pressurized by the frame structure such that generation of burr in the injection molded product may be restrained.
At least one of members that constitute the frame structure fit with the fixed mold or the moveable mold is fixed to either the fixed mold or the moveable mold, leaving a gap in the direction perpendicular to the die clamping direction.
The pressurizing mechanism is provided such that the pressing force is applied either in the die clamping direction or the direction perpendicular thereto, that is, the direction in which the member that constitutes the frame is not fixed. Accordingly the pressing force is applied to the die in the direction perpendicular to the direction for fixing the member that constitutes the frame.
The pressurizing mechanism is controlled in accordance with the amount of the resin injected into the cavity of the die.
According to the first aspect of the invention, an injection molding apparatus includes a die having a fixed mold and a moveable mold disposed to face with each other, and a frame structure that abuts on an outer surface of the die. In the injection molding apparatus, the frame structure is formed so as to be detachable with respect to the die, and the frame structure is formed by combining members each engaged with each other, and the members that form the frame structure are fixed to the die in at least one direction of a die clamping direction and a direction perpendicular thereto.
In a first aspect of the invention, rigidity of the die may be enhanced and the pressurizing mechanism is structured so as to be applicable to various types of die while being simply structured.
A predetermined gap may be formed between the member that forms the frame structure to be fixed to the die and a fixture in a direction perpendicular to a direction where the frame structure is fixed to the die. The invention is allowed to cope with deformation of the frame caused by the pressing force applied to the die. The deformation of the frame may be used to smoothly control the pressing force.
The frame structure may be provided with a pressurizing mechanism capable of pressing the die in a direction perpendicular to the direction where the frame structure is fixed to the die. In the invention, the deformation of the frame may be used to control the pressing force as well as prevent the die from being applied with the excessive pressing force.
The pressurizing mechanism may be formed as a hydraulic control mechanism. This makes it possible to simplify the structure of the pressurizing mechanism while generating a great magnitude of the pressing force.
The hydraulic control mechanism executes a control of a pressing force in accordance with an amount of a resin material injected into the die. This makes it possible to maintain the balance of the force applied to the inside and the outside of the die, thus reducing the load exerted thereto.
A resin pressure generated in the die of the injection molding apparatus may be partially received by the frame structure fit with the die. This makes it possible to reduce the load exerted to the die and enhance durability thereof. The rigidity of the die may further be enhanced during the injection molding method with the simplified structure.
A frame structure may be provided outside of a die having a fixed mold and a moveable mold disposed to face with each other, and a restoring force caused by an elastic deformation of the frame structure may function in resisting a resin pressure generated within the die. As a result, the resin pressure can be smoothly absorbed so as to easily cope with fluctuation in the resin pressure.
A frame structure may be provided outside of a die having a fixed mold and a moveable mold disposed to face with each other, and a pressurizing mechanism provided on the frame structure may serve to pressurize the die in a direction perpendicular to a die clamping direction so as to restrain deformation of a joint portion between the fixed mold and the moveable mold of the die caused under a resin pressure. This makes it possible to reduce generation of burr during the injection molding method so as to produce the molded product with higher molding accuracy.
The invention makes it possible to reduce deformation of the die caused under the resin pressure, and to restrain generation of burr. As the pressing force is applied to the die from outside thereof in the die clamping direction and the direction perpendicular thereto, deformation of the die caused under the resin pressure may be restrained, thus restraining generation of burr.
The thus simply structured apparatus according to the invention may allow deformation in the die during the injection molding method to be restrained, as well as generation of burr in the injection molded product to be restrained.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing a structure of an injection molding apparatus;
FIG. 2 is a perspective view showing a structure of a die to which a frame structure is fit;
FIG. 3 is a sectional view taken along line X—X of FIG. 2 , representing a structure of a pressurizing mechanism;
FIG. 4 is a view representing an assembled structure of the frame structure and the die;
FIG. 5 is a view representing a configuration formed of the die and the frame structure upon start of pressurization;
FIG. 6 is a view representing a configuration formed of the die and the frame structure under the pressurized state;
FIG. 7 is a graph representing a relationship between the resin amount and an amount of work oil supplied to the oil chamber;
FIG. 8 is a view representing a configuration formed of the die and the frame structure upon pressurization;
FIG. 9 is a view representing assembly of the frame structure and the fixed mold;
FIG. 10 is an enlarged view representing a fixed portion of the frame structure; and
FIG. 11 is a view representing a configuration where an oil bag is used as the pressurizing mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a structure of an injection molding apparatus of the invention.
In an injection molding apparatus 1 , a resin material is forced out of a cylinder 7 through a sliding operation of a plunger 8 so as to be supplied to a portion between a moveable mold 2 and a fixed mold 3 such that the resin material is molded. In the injection molding apparatus 1 , a cavity is defined by the moveable mold 2 and the fixed mold 3 , and connected to the cylinder 7 via a gate and the like. The resin material is introduced into the cavity by the amount corresponding to an injection stroke of the plunger 8 .
The moveable mold 2 and the fixed mold 3 are clamped, the respective outer surfaces of which are fit with a frame structure including two frames 4 and 5 . The frames 4 and 5 are assembled to surround the moveable mold 2 and the fixed mold 3 and to be fit with the die.
The frame 5 includes a pressurizing mechanism 6 so as to pressurize the die fit with the frames 4 and 5 . The pressurizing mechanism 6 serves to apply a pressing force to an outer side surface of the fixed mold 3 in the direction perpendicular to the die clamping direction, that is, the direction for clamping the moveable mold 2 and the fixed mold 3 .
The pressing force applied to the die is controlled in accordance with the amount of the resin injected into the die. The pressing force is coincided with the amount of the injected resin so as to prevent application of the pressure intensively to the joint portion when the resin pressure is not exerted to the die during its operation, thus protecting the joint portion of the die.
The configuration of the moveable mold 2 , the fixed mold 3 , and the frames 4 and 5 will be described.
FIG. 2 is a perspective view showing the die with which the frame structure is fit. FIG. 3 is a view taken along line X—X of FIG. 2 , showing a configuration of the pressurizing mechanism.
The frames 4 and 5 are fit with the clamped body of the moveable mold 2 and the fixed mold 3 . The pressure exerted to the moveable mold 2 and the fixed mold 3 upon injection of the resin is received by the frames 4 and 5 so as to improve the molding accuracy in the injection molded product without the need of enhancing rigidity of the moveable mold 2 and the fixed mold 3 . Accordingly each cost for producing the moveable mold 2 and the fixed mold 3 may be reduced.
The framers 4 and 5 serve to receive the force generated upon the injection molding in a die clamping direction and a direction perpendicular thereto, respectively. The frame 5 is formed into a substantially U-shaped and structured to be fit with a plane perpendicular to and in parallel with the die clamping direction with respect to the fixed mold 3 . The frame 4 serves to receive an assembled body of the moveable mold 2 , the fixed mold 3 and the frame 5 in its recess portion. That is, each inner end surface of the frame 4 abuts on each outer end surface of the frame 5 .
The frames 4 and 5 are engaged in the die clamping direction and the direction perpendicular thereto, thus receiving the force generated upon injection molding in the die clamping direction and the direction perpendicular thereto. Both ends of the frame 4 serve to restrict outward expansion of the respective ends of the frame 5 , thus enhancing rigidity of the frames 4 and 5 .
Referring to FIG. 3 , the frame 5 includes a structure as the a pressurizing mechanism that presses a plate under the hydraulic pressure. The pressurizing mechanism that includes an oil chamber 11 and a pressurizing plate 12 formed on the frame 5 is provided to face the surface of the fixed mold 3 in parallel with the die clamping direction. The pressurizing plate 12 is disposed within the oil chamber 11 so as to be slidably moved along the inner surface of the oil chamber 11 . Upon supply of the work oil into the oil chamber 11 , the pressurizing plate 12 slides inward to pressurize the fixed mold 3 .
FIG. 4 is a view representing an assembled structure of the frame structure and the molds.
The frame 4 is fixed to the moveable mold 2 , and the fixed mold 3 is fixed to the frame 5 . The die is formed by joining the moveable mold 2 and the fixed mold 3 in the die clamping direction, and accordingly the frames 4 and 5 are combined.
As the moveable mold 2 is fixed to the frame 4 , and the fixed mold 3 is fixed to the frame 5 , the die may be formed simultaneously with the combination of the frames 4 and 5 .
After joining the fixed mold 3 and the moveable mold 2 , the resin is injected into the cavity defined by the fixed mold 3 and the moveable mold 2 . As shown in FIG. 4 , the resin is injected to the center of the cavity such that the resin spreads toward portions in the cavity at both sides closer to the respective pressurizing mechanism.
The control mechanism of pressurizing operation will be described hereinafter.
FIG. 5 is a view representing the configuration of the die and the frame structure upon start of pressurization. FIG. 6 is a view representing the configuration of the die and the frame structure under the pressurization. FIG. 7 is a graph showing a relationship between the amount of the resin material and the amount of oil supplied to the oil chamber. Referring to FIG. 7 , the bold line stands for the change in the amount of the resin injected into the die with respect to time, and a double line stands for the pressure applied by the pressurizing mechanism with respect to time.
Referring FIG. 5 , when the amount of the resin material injected into the die reaches a predetermined value, the supply of the work oil to the oil chamber 11 of the frame 5 starts. Then the pressure within the oil chamber 11 rises to increase the pressing force applied by the pressurizing plate 12 . As shown in FIG. 6 , in the state where the cavity of the die is substantially fully filled with the injected resin material, the pressure within the oil chamber 11 becomes constant, thus making the pressing force constant.
As the pressing force is applied in accordance with the pressure of the resin injected into the cavity, the die becomes unlikely to deform in the process of injection molding.
The pressing force is controlled in accordance with the amount of the injected resin material as shown in FIG. 7 .
When the amount of the resin injected into the die reaches a constant value or greater, the hydraulic pressure to the oil chamber 11 rises. The pressure exerted to the oil chamber 11 is to be maintained after reaching the set value. The set pressure may be the same as the pressure of the injected resin. Accordingly this makes it possible to restrain deformation in the fixed mold 3 , resulting in improved molding accuracy.
Referring to the graph shown in FIG. 7 , when the amount of the resin injected into the die reaches the set value V 1 , the pressure of the pressurizing mechanism starts rising. The hydraulic pressure of the pressurizing mechanism is set to maintain the value P 1 . Once the pressure reaches the value P 1 , the hydraulic pressure serves to maintain the value P 1 .
The stroke of the plunger 8 for injecting the resin material may be detected to obtain the amount of the resin injected into the die. The force is applied to the die by the pressurizing mechanism 6 in the direction perpendicular to the die clamping direction in accordance with the stroke of the plunger 8 . As a result, the balance of the pressure exerted between the inner side and the outer side of the die is held so as to restrain deformation of the die.
As deformation of the die may be restrained, the degree of contribution of the die rigidity to the control for preventing the deformation is reduced, thus decreasing the cost for the die as well as the cost for producing the injection molded product.
The deformation of the frame structure upon pressurization will be described.
FIG. 8 is a view showing the configuration of the fixed mold and the frame structure upon pressurization.
When the pressing force is generated upon supply of the work oil into the oil chamber 11 , the portion of the frame 5 at which the pressurizing mechanism is disposed is bent. At the portion of the frame 5 at which the pressurizing mechanism is disposed, one side end portion is engaged with the frame 4 , and the other side end portion is connected to the frame 5 . The portion of the frame 5 at which the pressurizing mechanism is disposed is likely to be deformed. The portion of the frame 5 at which the pressurizing member is disposed is elastically formed so as to maintain rigidity of the die without exerting excessive force to the fixed mold 3 by the pressurizing mechanism as well as improve the molding accuracy of the injection molded product. As the pressing force may be adjusted by deformation of the frame, the frame structure is formed into a simple structure, thus reducing the manufacturing cost.
The portion of the frame 5 at which the pressurizing mechanism is disposed is made elastic. Accordingly, this makes it possible to expand the oil chamber 11 by deforming the elastic portion of the frame 5 outward while maintaining the position of the fixed mold 3 such that the pressing force through the supply of the work oil can be easily controlled.
Fixation of the frame 5 to the fixed mold 3 will be described hereinafter.
FIG. 9 is a view representing fixation of the frame to the fixed mold. FIG. 10 is an enlarged view of the portion at which the frame is fixed to the fixed mold.
The frame 5 is fixed to the outer surface of the fixed mold 3 in the direction perpendicular to the die clamping direction. The fixed mold 3 has holes 23 extending along the die clamping direction. Screws 21 each fit in a hole 22 formed in the frame 5 with a gap are tightened through the holes 23 . The hole 22 of the frame 5 has a diameter larger than that of the screw 21 such that the head of the screw 21 is engaged with the frame 5 so as to be fixed to the fixed mold 3 .
The frame 5 has an elastic portion at which the pressurizing mechanism is disposed. The portion of the frame 5 to be fixed to the fixed mold 3 extends in the direction perpendicular to the die clamping direction. That is, the portion of the frame 5 that connects the portion at which the pressurizing mechanism is disposed is extended by the reaction force upon pressurization of the pressurizing mechanism.
The diameter of the hole 22 formed in the extensible portion of the frame 5 is larger than that of the screw 21 . The frame 5 is fixed to the fixed mold 3 in the direction perpendicular to the direction in which the extensible portion of the frame 5 extends. Even if the extensible portion of the frame 5 extends, fixation of the frame 5 to the fixed mold 3 may be maintained without disturbing deformation of the frame 5 .
The aforementioned structured die and the frame structure that surrounds the die may restrain deformation of the fixed mold 3 caused upon injection of the resin material and prevent generation of burr during the injection molding method using elasticity of the frame 5 . The pressing force may be applied to the die using the elasticity of the frame 5 that smoothly follows up the deformation of the fixed mold 3 . Accordingly the pressing force can be easily controlled.
Another structure of the a pressurizing mechanism will be described.
FIG. 11 is a view that represents the pressurizing mechanism in the form of an oil-bag.
Referring to FIG. 11 , the pressurizing mechanism is formed of a pressurizing plate 12 that receives the pressure applied by an oil-bag 25 . The pressurizing plate 12 and the oil-bags 25 , 25 are disposed within the oil chamber 11 of the frame 5 . More specifically, the oil-bags 25 , 25 are disposed on the inner side of the pressurizing plate 12 within the oil chamber 11 . The work oil is supplied to the oil-bags 25 , 25 so as to be expanded such that the pressurizing plate 12 is pressed against the fixed mold 3 . This makes it possible to apply the pressing force to the fixed mold 3 .
The use of the oil-bag 25 may reduce the possibility of leakage of the work oil as minimum as possible as well as improve adjustability of the pressurizing plate 12 or the frame 5 .
Alternatively the pressurizing mechanism may be formed of an air-bag in place of the oil-bag depending on the state of the use of the die.
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An injection molding apparatus has a die having a fixed mold and a moveable mold disposed to face with each other. A frame structure is detachably provided on the outer surfaces of the fixed mold and the moveable mold, that is, opposite to the surface of the cavity defined by the fixed mold and the moveable mold. Each frame that constitutes the frame structure has a shape that can be combined together. One of frames provided on the fixed mold or the moveable mold is fixed thereto in a die clamping direction or a direction perpendicular thereto. The frame is fixed to the fixed mold of the die, leaving a predetermined gap in the direction perpendicular to that for fixing the frame structure to the die. The pressurizing mechanism that applies a pressing force in the direction other than for fixing the frame structure to the die. The hydraulic control mechanism is employed as the pressurizing mechanism.
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BACKGROUND OF THE INVENTION
This invention relates to wheelchairs and, more particularly, to hand rims for hand-propelled wheelchairs.
Many conventional hand-propelled wheelchairs are equipped with tubular steel hand rims with a circular cross-section. Each hand rim is usually mounted outboard of its respective wheel by connectors, such as spacers (standoffs), to provide a clearance between the hand rim and wheel. Some lightweight wheelchairs are equipped with integral hand rim and wheel rim assemblies. A combined hand rim and wheel rim for a wheelchair can also be formed from a single extruded section.
Wheelchair hand rims enable the wheelchair user to control the wheelchair's movement, such as acceleration, turning and braking. While generally suitable for their intended purpose of propelling and maneuvering the wheelchair, conventional wheelchair hand rims have numerous disadvantages. For example, the smooth metal surfaces of wheelchair hand rim tubing sections provide only limited gripping surfaces for the user. Furthermore, when the weather is humid, damp or rainy, or if the user's hands are perspiring, the wheelchair hand rims can become slippery. Often, when the user attempts to propel the chair in difficult situations, as when going up ramps, traveling on wet pavement, moving on soft carpets, traversing dirt or gravel areas, grass or other rough terrain, the user often experiences difficulty and must resort to such tactics as placing their hands over both tires and hand rims to exert sufficient torque. Moreover many users push forward with the help of the tire to increase friction. Dirt and debris on the tires, and glass, stones or metal objects stuck in the tire can dirty and even injure the user's hands. The standard hand rims also limits the ability of the user to properly and safely control the brake the wheelchair while descending a ramp. Also, a considerable amount of the user's effort is expended in gripping the slippery metal hand rims rather than in applying torque to propel the wheelchair.
In the marketplace today there are coated hand rims for wheelchairs and non-coated hand rims for wheelchairs. Coated hand rims can be used by people with reduced hand strength or function. Coated hand rims offer somewhat higher friction. There are different types of coatings available in the market place including hard coatings, such as hard vinyl and hard urethane, and soft coatings, such as soft vinyl and molded isobutyl foam rubber. However, the disadvantages of coated hand rims are that when braking the high friction coated hand rims cause the hands to get very hot which can bum or otherwise injure the user's hands. Furthermore, most conventional coated hand rims are not very durable, and often become unusable in less then six months. Hard coatings can be easily chipped away with use, creating sharp edges which can cut the user's hand. Soft coatings, such as soft vinyl and isobutyl foam, do not have sharp edges, but have a much shorter life. The non-coated hand rims are used primarily by people with full strength and function in their hands. For most users with full hand strength and function, the disadvantages outweigh the benefits and most buy non-coated hand rims. All users could however, benefit from additional traction when accelerating.
In recent years wheelchair sports have become increasingly popular, and have prompted changes directed toward making wheelchairs more easily and efficiently maneuverable. Sport wheelchairs are often equipped with hand rims formed from a slightly larger diameter tubing which improves the grip to some extent. The grip may be further improved by providing a soft vinyl coating on the hand rim, but this has the disadvantage of considerably diminishing the durability of the hand rim.
A different set of problems may be presented for paraplegics, quadrapalegics, users with multiple sclerosis and others having limited grip strength. Some conventional hand rims for such users utilizes a circular ring similar to regular hand rims, but having plurality of radially or axially projecting handles or push rods which the user may push with their palm without having to grip. These so-called projection hand rims are useful when required, but are heavy and relatively expensive. Moreover, they are extremely awkward and unsuitable for general use. The main problem with projection hand rims with push rods is difficulty in braking. Also, the push rods can become caught up on draperies, furniture, and the like. Some wheelchairs utilize a system in which push rods are partially retracted towards the bottom of their travel, thereby at least partially obviating this problem. However, this result is achieved at the expense of complexity.
It is, therefore, desirable to provide an improved wheelchair hand rim which overcomes most, if not all, of the preceding problems.
SUMMARY OF THE INVENTION
An improved wheelchair hand rim assembly is provided to better enable the wheelchair user to control the wheelchair's movements, such as cruising, turning, maneuvering, propelling, accelerating, decelerating, braking and stopping. The reliable light-weight hand rim assembly can be readily and easily grasped to power, control and propel the wheelchair to the desired speed by the user without having to grasp the tires and wheels of the wheelchair and dirty the user's hands. Desirably, the user-friendly durable hand rim assembly can safely brake a wheelchair without burning or injuring the user's hands or otherwise harming the user. The beneficial economical hand rim assembly can be comfortably used by paraplegics, quadrapalegics, patients recovering from surgery, elderly patients, and others who are having difficulty walking.
The novel power grip hand rim assembly, also referred to as a power grip hand rim, provides a dual friction or multi-friction hand rim or push rim. In order to better control braking, speed and movement of the wheelchair, the hand rim assembly has a braking rim portion to manually brake deceleration and stop the wheelchair and has a propulsion push rim portion to manually propel, accelerate and advance the wheelchair in a forward or rearward direction, as desired. The braking and propulsion rim portions are molded, fabricated or otherwise constructed of different materials and cooperate with each other to provide a dual friction composite rim assembly.
In the preferred form, the braking rim portion comprises a rim, annular braking member, or brake with a manually grippable braking surface that is positioned laterally outwardly and outboard of the propulsion rim portion. The braking rim portion can be molded or extruded of low friction medical grade material, such as: impact-resistant plastic, carbon-reinforced plastic, fiber-reinforced plastic, or metal, such as rolled steel, stainless steel, aluminum or preferably titanium. For even lower friction, the griping surfaces of the braking rim portion can be smooth, glossy, waxed, or polished. To accommodate the desires and aesthetic appeal of the user, the braking rim portion can be tempered, hardened or surface treated and can be chrome plated, brass plated, painted or anodized. The braking rim portion can have retention fingers and/or a recessed area defining a groove to snugly receive and retain the propulsion rim portion.
In the preferred form, the propulsion rim portion comprises a power grip traction ring, drive rim, or annular upright propulsion member. The propulsion rim portion can have a manually grippable, circumferential, propulsion surface and can have slits, knurling, protuberances, texturing or channels to enhance gripping. Advantageously, the propulsion rim portion of the dual friction rim assembly comprises a material having a higher coefficient of friction than the braking rim portion. The propulsion rim portion can be molded, extruded, fabricated or otherwise made of elastomeric material, such as natural rubber, neoprene rubber, or rubber-like plastic, silicon-rubber, polyurethane and blends or combinations of the preceding. In the illustrated embodiment, the propulsion rim has an outer grippable section providing a power grip and has a wider inner engageable section which is disposed radially inwardly of the outer grippable section to firmly hold and wedge the propulsion rim portion in the braking rim.
The new type of wheelchair hand rim or push rim combines two or more features that have not previous been available in conventional hand rims. The construction and arrangement of the novel hand rims provide high friction when accelerating and low friction when braking. Advantageously, the inventive wheelchair hand rim enables the user to propel the chair with the expenditure of significantly less energy, thereby greatly increasing mobility. The user is able to apply increased torque with less grip effort on all points of the power stroke in both the forward and backward directions, and is left with more reserve for difficult situations.
The sloping gently curved braking portion blends smoothly with the upper curved portion of the traction rims to provide an effective palm grip surface. The outboard metal surface of the dual friction hand rim provides a smooth braking surface on which the user's thumb rests while leaving an elastomeric crown over the top of the traction ring for providing more traction area.
Furthermore, the improved hand rim can be suitable for users having extremely limited grip strength. This hand rim avoids the need for radially or axially projection push rods that have difficulty in braking and tend to get caught up on furniture and other objects in the environment. At the same time, the hand rim is of a simple and lightweight construction.
Power grip hand rims can be produced in a variety of types and sizes to fit most wheelchair brands and models. The power grip hand rims can also be made available with an easy-to-install mounting kit, complete with mounting instructions for various types of rims such as tab or bolt mount.
The power grip hand rims of this invention provide a superb grip to manual wheelchair users with varying degree of abilities. Primarily for everyday use, the power grip hand rims can also be used on quadriplegic's rugby chair and for a variety of sports chairs. Their tacky, rubberized surfaces enable quadriplegics and others to propel themselves forward with more control and less effort than with a standard aluminum or coated hand rim. For quadriplegics, paraplegics, and others, the power grip hand rims prevent cuts on hands caused by sharp edges of plastic coating that has chipped away as in conventional coated hand rims. The power grip hand rims also retain their grip in all weather conditions, and are resistant to extreme heat or cold. Desirably, the power grip hand rims are extremely durable, so replacing conventional hand rims every six months will become a thing of the past. The power grip hand rim offer a superior value to the wheelchair user because it outlasts most coated hand rim alternatives, while adding comfort and control to their everyday lives.
A more detailed explanation of the invention is provided in the following description and appended claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a wheelchair equipped with hand rims in accordance with principles of the present invention;
FIG. 2 is a cross-sectional view of a hand rim taken substantially along line 2--2 of FIG. 1 in accordance with principles of the present invention;
FIG. 3 is cross-sectional view of another hand rim taken substantially along line 2--2 of FIG. 1 in accordance with principles of the present invention; and
FIG. 4 is a cross-sectional view of still another hand rim taken substantially along line 2--2 of FIG. 1 in accordance with principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a hand propelled (manually propelled) wheelchair 20 equipped with a pair of dual friction composite power grip hand rim assemblies 22 and 24, also referred to as power grip hand rims. The wheelchair can have a horizontal seat 26, an upright back 28 and a chair frame 29 with rearwardly extending handle bars 30 above, along or from the back. The handles can include rubber or plastic elastomeric finger grippable covers providing push handles 31. The seat and back can comprise cushions and be padded. The seat can be constructed of woven fabric, leather, plastic webbing, cane, bamboo or other material. The chair frame can have upright rearward (back) posts 32 and 34 to support the back and the push handles. Webbing can extend between the back posts to further support the back. The back and upper portion of the rearward posts can be removed for quadrapalegics who prefer to lie and control the wheelchair on their stomach.
The chair frame can be made of metal tubing and can have horizontal arm rests 36 and 38 and side rails 40 and 42 along the sides of the seat. The chair frame also has front posts 44 and 46 and a seat frame 48. The front posts extend downwardly from the arm rests to a position below the seat and above the front wheels, casters or rollers 50 and 52. The front wheels can be connected by front sockets or swivel joints 54 and 56 and clamps or other connectors to the front posts or to a front bar 58 which extends horizontally between and connects the front posts. The wheelchair can have back wheels, casters or rollers 60. The back wheels can be connected by back sockets or swivel joints 62 and clamps or other connectors to the back posts or to a back bar 64 which can extend horizontally between and connect the back posts.
The arm rests, side rails and seat frame extend horizontally between and connect the front and back posts. The seat frame has a rectangular shape with a front, sides and a back portion. Webbing can extend between the sides or front and back portion of the seat frame to further support the seat. Sides bars 66 can extend laterally between and connect the front and back bars. The wheelchair can also have foot rests or foot plates 70 and 72 which can be connected by diagonal articulated leg supports or braces 74 and 76 to the seat frame, front post or front bar via leg sockets or swivel joints 78 and 80.
The wheelchair has a pair of large diameter drive wheels 82 and 84 positioned along the sides of the wheelchair. The drive wheels are much larger than the front and back stabilizing wheels or casters. The drive wheels can extend from the floor or pavement to a position in proximity to or slightly above the seat. Each drive wheel can have: a hub 86, spokes 88 extending radially between and connecting the hub to an outer drive wheel-rim 90, and a tire 92 mounted on the drive wheel-rim. The tire can be pneumatic or non-pneumatic. The hubs of the drive wheels can be connected to an axle, shafts or chair frame via bearings. The hub can enclose gears or contain suitable gearing for first gear, second gear, third gear, etc.
The hand rim assemblies 22 and 24 provide power grip hand rims or push rims which are positioned laterally outwardly and outboard of the drive wheels. The hand rim assemblies can be connected to the outer drive wheel-rim by suitable connecting devices 94, such as: bolts, bushings, bars, clamps, couplers, welding, pins, extenders, spacers, standoffs, or other fasteners. The hand rim assemblies are designed and constructed to be comfortably gripped by the person in the wheelchair, i.e., the wheelchair user. One hand rim assembly, such as the left hand rim assembly drives and can be connected to the left drive wheel. Another hand rim assembly, such as the right hand rim assembly drives and can be connected to the right drive wheel. For persons with the use of only one hand, one or both hand rim assemblies can be positioned on the side of the wheelchair in proximity to the person's useful hand, but are capable of driving both drivewheels. The maximum diameter of the hand rim assemblies are slightly smaller than the maximum diameter of tires of the drive wheels so that the hand rims do not touch the pavement or floor and pickup dirt, pebbles, sharp objects or other debris which could dirty and harm the user's hands. The wheelchair hand rim assemblies, therefore, remain clean and protect and keep the user hands.
The user-friendly hand rim assemblies are grasped, pushed and controlled by the wheelchair user to cruise, turn, maneuver, propel, accelerate, decelerate, brake and stop the wheelchair. Each hand rim assembly can have a power grip traction ring 100 and a tubular metal braking rim 102. The traction ring comprises an elastomeric annular propulsion rim or rubber-like circular rim portion to manually propel the wheelchair, either forwardly or backwardly, as desired. The braking rim comprises a smoother metal rim, circular brake or annular braking portion to manually brake, restrain and stop the wheelchair. The metal braking rim of the dual friction hand rim has a lower coefficient of friction than the traction ring. The traction ring and braking rim cooperate with each other to form a multi-friction composite power hand rim to better control, accelerate, maneuver and brake the wheelchair.
The traction ring 100 can comprise a solid elastomeric propulsion rim made of rubber, rubber-like plastic, neoprene, silicon, or polyurethane, or combinations or blends thereof. The traction ring can have an outer grippable circumferential section 104 (FIG. 2) and an inner interior section 106. The grippable section of the traction ring can have a resilient, grippable, outer curved surface 108, which can extend from 15° to 90° to cushion the user's hands. The curved surface can be arcuate and can comprise a convex textured surface or crown to facilitate gripping. The textured surface can have peaks and valleys providing channels 110 to further enhance gripping and to define passageways for flow of water when the wheelchair is being propelled and moved in the rain or when driving over wet surfaces. If desired, the textured surface can have bumps, protuberances, knurling or finger-grips to enhance gripping.
The inner section 106 of the traction ring is disposed radially inwardly of and is integrally connected to the grippable outer section of the traction ring. The inner section is preferably wider and thicker than the outer section of the traction ring for enhanced structural strength. To this end, the inner section's side walls 112 and 114 and bottom 116, are wider and have a greater span than the outer section's side walls 118 and 120 and top comprising the outer surface 108.
The braking rim 102 can be made of impact-resistant medical grade metal, such as stainless steel or polished metal and is preferably made of extruded polished or smooth, light weight aluminum or anodized aluminum, and most preferably titanium, for best results. The braking rim can have a hollow interior compartment 122 to decrease the weight of the braking rim and wheelchair for faster speed and ease of transport. The braking rim can have a generally U-shaped cross-section 124 and a channel section 125. The U-shaped cross-section can extend from 270° to 345°. The curved outer end portions or tips 126 and 127 of the braking rim's U-shaped cross-section provides a circular edge. The minimum spacing between the outer end portions or tips is preferably less than the maximum span and distance of the braking rim's channel and bridging portion to further securely grasp, wedge and connect the traction ring.
The braking rim's channel section extends between and is integrally connected to the U-shaped cross-section. The channel section defines a channel 128 which has a shape and configuration that is generally complementary to and a mirror image of the traction ring's inner (interior) section to snugly receive and firmly hold the traction ring. The channel section's sides 130 and 132 are positioned and wedged against and abuttingly engage the side walls of the traction ring's inner section. The channel section has a bridging portion 134 providing a bight which extends between and connects the channel section's sides to securely support and abuttingly engage the bottom of the traction ring. The U-shaped cross-section and the channel section are integrally connected and cooperate with each other to substantially enclose and surround the hollow interior compartment of the braking rim.
In order to safely and efficiently facilitate braking, the braking rim has a grippable braking surface 136 which is positioned laterally outwardly and outboard of the traction ring. The braking surface can be convex, curved, and rounded and is shaped with a sufficient radius to comfortably receive the palm and fingers of the user's hands. Preferably, the outer braking surface is generally smooth to prevent burning and injury to user's hands during braking and gripping, while the wheelchair is in motion. The opposite inner (inboard) surface 138 of the braking rim can be symmetrical to the braking surface. In the illustrative embodiments, the braking surface and inner surface are flush with the crown and outer grippable surface of the traction ring.
In the embodiment of FIG. 2, the side walls 140 and 142 of the traction ring and the sides 144 and 146 of the braking rim's U-shaped cross-section are slanted or beveled outwardly at an angle of inclination ranging from 10° to 60° from the vertical, and provide inclined side portions which diverge radially outwardly.
In the embodiment of FIG. 3, the side walls of the traction ring and the sides of the braking rim's U-shaped cross-section are flared or inclined inwardly at an angle of inclination of 10° to 75° from the vertical, and provide inclined side portions which diverge toward the hollow interior compartment of the braking rim. The traction ring's inner section and the braking rim's channel section can also have interlocking fingers or teeth to further secure and firmly connect the traction ring to the braking rim.
In the embodiment of FIG. 4, the traction ring's inner (interior) section and the braking rim's channel section have an inverted mushroom-shaped head or bulb-shaped foot which provides enlarged base portions 150 and 152. The base portions also provide interlocking complementary fingers 154 and 156 to further connect and firmly secure the traction ring and braking rim.
From the above description, it can be appreciated that the hand rim comprises two main parts: a braking rim and a traction ring. When the hand rim is viewed from the side as if looking towards the wheelchair with the wheel behind the hand rim, the side surface of the braking rim is clearly visible and the traction ring is barely visible. When the hand rim is viewed from the top as the user would see it when sitting in the wheelchair, the friction surface of the traction ring is clearly visible.
The braking rim is circle shaped with a cross section that allow the traction ring to stay in the hand rim. The traction ring and braking rim can have different cross-sectional configurations, such as shown in FIGS. 2, 3 and 4. The cross-sectional configuration can be made to the preferences of the user and is somewhat dependent of what type of equipment is used to manufacture the rim and the traction ring.
The braking rim can be made of extruded aluminum, molded plastic, rolled steel or other material. The traction ring is a separate ring made of rubber or another pliable material that has a high coefficient of friction. The traction ring has a cross section that allows it to be readily gripped. The traction ring and braking rim are secured together to form a dual friction wheel chair hand rim.
The inner core comprising the braking rim of the hand rim can be made of aircraft aluminum (6061-T6) which makes it extremely strong yet lightweight. The traction ring can be made of durable rubberized elastomer, giving the user unmatched power not available through foam or plastic-coated alternatives.
The traction ring can be transfer or injection molded to the desired shape. The shape is such that traction ring can stay in the braking rim without adhesive. The traction ring can have a textured surface to enhance the gripping in wet weather. Three or more sizes of traction ring are available to fit different variations and preferences of hand rim users.
The braking rim can be rolled in a conventional way, to the desired diameters and mounting tabs can be welded on for applications that require them, if the rim is made of extruded aluminum tubing. The hand rim can be anodized in a desired color. A motor driven drum with a guiding roller can be used to fabricate braking rims. Other methods such as a standard three roller, rolling machine or a cam bender can be used. If the braking rim is made of formed steel tubing it could be rolled made with similar equipment. If the braking rim is made of synthetic material, it can be molded to the desired shape.
After the braking rim is formed, the traction ring is applied to assemble the hand rim. The traction ring could be applied with two rollers that squeeze it on, or the traction ring could be mounted with other methods such as a vacuum machine that automatically presses the rubber on. The traction ring could also be applied by hand.
The dual friction hand rims enable the user to push forward on top of the rims using the high friction coefficient of the traction rings to get good traction. This will greatly assist the users that have reduced hand function and/or strength. When going down hill, the user can put the hands against the side of the braking rim, where the friction is less and therefore steer and brake smoother. Should an emergency come up, the user can use the top surface to stop quickly. The features of the dual friction hand rim make this hand rim safer and better to use then any other hand rim.
The overall height of the traction ring provides a relatively large amount of hand rim surface for frictional engagement with the user's hand. The contour of the hand rim allows the user to comfortably and securely grip the hand rim. The curvature of braking rim further enhances the palm grip. It is desirable to maintain a minimum hand rim width in order to minimize the overall wheelchair width and facilitate access of the user and wheelchair into tight places. At the same time, it is desirable for control and comfort purposes to have a relatively gentle curvature. The curvature of the hand rim affords a firm grip and smooth control when the user is descending ramps as well as when travel on a flat surface or bumpy terrain. The traction ring provides good traction for acceleration and propulsion.
It can be appreciated that the present invention provides a very useful wheelchair hand rims that permits the user to make the most effective use of their effort. The hand rims are configured so that the hands and palms tend to naturally fit and close around the wheelchair hand rims when pushing and pulling thereon. The curved dual friction contour allows the user to more effectively utilize and apply force to the wheelchair hand rims.
It can further be appreciated that while the power grip hand rims are shown for use with the illustrated wheelchair, the power grip hand rims can be used with most other types of wheelchairs, including sports wheelchairs.
Among the many advantages of the improved wheelchair hand rims of the invention are:
1. Superb performance.
2. Excellent wheelchair maneuverability, handling and braking.
3. Better protection for the user's hands.
4. Easy to use.
5. User-friendly.
6. Good wear.
7. Convenient.
8. Safe.
9. Inexpensive.
10. Attractive.
11. Dependable.
12. Durable.
13. Comfortable.
14. Effective.
Although embodiments of the invention have been shown and described, it is to be understood that various modifications and substitutions, as well as rearrangements of parts, components, and assembly steps, can be made by those skilled in the art without departing from the novel spirit and scope of this invention.
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A convenient power grip hand rim assembly provides a user-friendly economical push rim to easily and safely control, maneuver, accelerate and brake a wheelchair. The dependable dual friction hand rim assembly can have a rubber-like traction ring providing a propulsion rim portion to propel the wheelchair and can have a smooth metal rim, brake or braking rim portion to restrain and brake the wheelchair without burning or otherwise injuring the user's hand. The power traction ring and braking rim can come in different cross-sectional configurations depending on the method of manufacture as well as to accommodate the preferences of the user and can have a special gripping surface to facilitate gripping. The braking rim portion can be made of titanium, aluminum, stainless steel or other medical grade metal and can be surface treated, tempered, hardened, coated, waxed, chrome plated, brass plated, painted or anodized to accommodate the desires and aesthetic appeal of the user.
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BACKGROUND OF THE INVENTION
This invention relates of a process for the preparation of 3,5-xylenol from 3,5,5-trimethylcyclohexen-2-one (isophorone). 3,5-Xylenol and related xylenol isomers are useful as disinfectants and starting materials for the preparation of resins.
It is known from U.S. Pat. No. 2,369,196 that isophorone can be converted to 3,5-xylenol by heating isophorone at temperatures between 668° and 676° C. The yields of product, however, are relatively low (39%). It is also known to use a variety of solid catalysts to improve the yield. Examples of such catalysts are activated alumina disclosed in U.S. Pat. No. 2,369,197 and a chromium (III) oxide-copper (I) oxide mixture known from British Patent specification No. 1,197,803. A disadvantage of such solid catalysts is that during the conversion reaction a carbon deposit is formed on the catalyst. This leads to a decrease in catalyst activity and necessitates stopping the reaction at intervals in order to regenerate the catalyst.
It has now been found that isophorone can be converted to 3,5-xylenol in good yield using certain homogeneous catalysts.
SUMMARY OF INVENTION
The present invention, therefore, relates to an improved process for the preparation of 3,5-xylenol which comprises heating isophorone at a temperature of from about 450° to about 650° C in the presence of a homogeneous catalyst comprising a halogen having an atomic number of at least 17 or an organic compound containing said halogen, said organic compound being selected from the class consisting of halogen substituted-saturated aliphatic, unsaturated aliphatic and aromatic compounds.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The halogen catalyst for the process of the invention, in molecular form, may be chlorine, bromine or iodine. The halogen substituted, organic compound catalyst of the invention may contain any of these three halogens, but is preferably an iodine-containing compound. The halogen-containing organic compound may be a saturated or unsaturated aliphatic compound or an aromatic compound. The aliphatic compound preferably contains from 1 to 6 carbon atoms, and may be for example, a haloalkane such as methyl iodide, n-butyl bromide or carbon tetrachloride, or an allyl halide such as allyl bromide. The aromatic compound may be a phenyl halide such as phenyl iodide. The amount of catalyst may be from 0.01 to 20%w, and is preferably from 0.1 to 5.0%w based on the weight of isophorone.
The process is preferably carried out at a temperature of 550° to 650° C. The pressure is conveniently atmospheric pressure, although the process may also be carried out at sub-atmospheric or super-atmospheric pressures.
In one embodiment the process is carried out continuously by passing the isophorone and the catalyst through a heated tube reactor. The isophorone and the catalyst may also be mixed with an inert diluent, for example nitrogen or an alkane, in order to improve the selectivity of the process and/or the heat transfer in the reactor. In some circumstances it may also be advantageous to irradiate the reaction mixture with ultra-violet radiation.
The 3,5-xylenol may be recovered from the reaction mixture and purified by any suitable method, for example by distillation. From the economic point of view it may also be desirable to include in the process a separate recovery step for the halogen or halogen-containing organic compound.
The invention is illustrated further in the following Examples.
EXAMPLES 1 TO 12
To evaluate the effectiveness of the homogeneous catalysts of the invention, a series of tests were performed in a heated tubular reaction vessel wherein isophorone was converted to 3,5-xylenol with different halogen-containing catalysts according to the invention at varying catalyst concentrations, reactant space velocities and temperatures.
The reactor consisted of a stainless steel tube of length 320 mm and diameter 10 mm fitted with a thermocouple of diameter 5 mm along its whole length. The tube was surrounded by an electrically heated oven. The catalyst was dissolved in isophorone and the mixture was passed at a constant space velocity through the heated tube. The product was dissolved in acetone and analysed by gas-liquid chromatography.
The results of the various examples as well as further details of the operating procedures are set out in the Table below.
The yields of product from a number of experiments were combined (total 548.6 g) and distilled under reduced pressure. 3,5-Xylenol having a purity of more than 99% was obtained in 85.4% yield, b.p. 90°-95° C at 1 mm Hg.
TABLE__________________________________________________________________________ Catalyst Space Concentration Velocity Conversion Selectivity (%w based on Temperature (ml.ml Isophorone to 3,5-XylenolExampleCatalyst Isophorone) (° C) Reactor,hr) (%) (%)__________________________________________________________________________1 methyl iodide 0.1 600 0.33 93.9 79.92 " 0.5 600 0.33 97.6 83.23 " 1.0 475 0.33 30 944 " 1.0 570 0.5 100 855 " 1.5 570 0.5 100 936 " 5.0.sup.a 570 0.5 100 957 " 10.0 550 0.66 100 858 n-butyl bromide 1.0 600 0.33 94.8 80.49 carbon tetrachloride 1.0 600 0.33 96 6510 allyl bromide 1.2 570 0.8 75 8111 phenyl iodide 1.3 570 0.3 99 8612 bromine.sup.b 2.4 570 0.6 76 84Comparative none -- 600 0.023 70 50__________________________________________________________________________ .sup.a Reaction mixture was diluted with nitrogen; molar ratio N.sub.2 : isophorone = 1 : 4. .sup.b Used as solution in benzene (9.3 g Br.sub.2 per 100 ml C.sub. 6 H.sub.6).
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3,5-Xylenol is prepared in high yield from isophorone by heating isophorone at a temperature of from about 450° to about 650° in the presence of a halogen having an atomic number of at least 17 or an organic compound containing such a halogen.
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BACKGROUND OF THE INVENTION
This invention relates to workholding chucks as used on automatic turning machines. Automatic turning machines generally utilize long bars for work feed stock which extend through the spindle of the head stock of the machine out of the front of the spindle and though a work holding chuck. As a workpiece is finish-machined and cut off from the parent bar stock, the grip of the workholding chuck can be relaxed and the bar is fed outward to present new material for machining. Many types of bar feeder attachments are used to increment stock through the work spindle. There are pushers which urge the workstock forward from the rear of the headstock and there are pull type attachments which grab a part and withdraw it from the front of the chuck. It is with this latter type of attachment that the present invention can be used most advantageously.
After withdrawing additional stock through the chuck for the next successive machine operation the chuck reclamps on the workstock. At this time, it is imperative that there be sufficient clamping stock present within the clamping area. If this condition is not met and there is not sufficient clamping stock present in the clamping area, a real and active danger exists, in that as the workpiece is rotated and a cutting tool is engaged against the workpiece, it may be "cammed" out of the clamping position due to forces generated by the cutting action. Additionally, in the absence of sufficient clamping stock, the chuck may not be operating at its proper design forces and may tend to have overstressed points which could operate to the detriment of the chuck assembly and cause failure of the components. For example, if a jaw type chuck is used for clamping the work stock and there is not sufficient stock to cover the clamping face of the jaws, high unit stresses will be developed over the zone of the clamp and high bending stresses may be developed in the jaw bodies as well. Since the jaws are normally subjected to great stresses because of the fly-away tendencies of centrifugal action, the internal stresses are compounded and may cause failure of the jaws.
Most prior art devices for sensing the presence of stock to allow adequate clamping have also included cumbersome mechanical devices which reach through the headstock spindle and touch the end of the workpiece. These devices, however, are impractical to use and function. Similarly, stock feelers have been contained within a chuck body which necessitates having a complex chuck unit and feedback sensing control. Many of these disadvantages have been alleviated by the stock sensing device disclosed in applicant's U.S. Pat. No. 3,982,085. The present invention, likewise, alleviates many of these prior art problems with further elimination of mechanical features and increased simplicity. It provides an alternative method of stock sensing with additional cost savings.
SUMMARY OF THE INVENTION
The invention relates to a stock sensing device which, in the preferred embodiment, is used to sense sufficient chucking stock for a chuck with workgripping members. The apparatus utilizes a source of pressurized fluid which is directed into a receiving channel for a workpiece. A seal around the channel yieldably engages the periphery of the workpiece and cooperates with the workpiece to restrict fluid flow from the channel. This flow restriction creates a backpressure, the magnitude of which is indicative of the presence or absence of the workpieces at the seal location. A signal, corresponding to the presence or absence of a workpiece at the seal, is generated when the backpressure exceeds a predetermined level and is used to control functions of the machined tool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a turning machine utilizing a form of the present invention.
FIG. 2 is a front elevational view of the turning machine of FIG. 1 with the housing removed for clarity of illustration.
FIG. 3 is a front elevational view, partially in cross-section, of the rotary union and quick disconnect coupling utilized in the embodiment of FIG. 1.
FIG. 4 is a cross-sectional view of the hydraulic cylinder utilized in FIGS. 1 and 2, with details emitted for clarity.
FIG. 5 is an elevational view, partially cut away and partially in cross-section illustrating the positioning of a flexible brush seal positioned proximally to the chuck jaws.
FIG. 6 is a fragmentary sectional view in the direction of line 6--6 in FIG. 5 illustrating the flexible brush seal of the preferred embodiment.
FIG. 7 is a diagramatic illustration of a pneumatic circuit which might be employed on the embodiment of FIG. 1.
FIG. 8 is a diagramatic illustration of a control circuit which might be employed for controlling the stock sensing device of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and to FIGS. 1 and 2 in particular, a turning machine 1 having a rotating workholding chuck 2 is shown holding a workpiece 3. The chuck 2 is mounted to a face of a spindle 4 for rotation therewith. A draw tube 5 (shown in cross-section views of FIGS. 5 and 6) extends from the chuck 2 and beyond the housing 6 within the spindle 4. The draw tube 5 terminates in a rotating hydraulic cylinder 7 where it is axially moved by a piston 8 (FIG. 4) contained within the cylinder 7. An extension 9 from the cylinder 7 is capped by a quick disconnect coupling 10 which is connected to a rotary union 11. A fluid supply pipe 12 is joined in fluid communication with rotary union 11 and supplies a pressurized fluid, preferably air, to a channel 13 extending from the end of extension 9 through coupling 10, hydraulic cylinder 7, draw bar 5, and chuck 2 to the ambient atmosphere. A plastic liner 14 (FIGS. 3-5) lines substantially all of channel 13 and extends from the chuck 2 to the coupling 10.
As shown most clearly in FIGS. 4 and 5, the draw tube 5 transmits a linear force to several pivoted levers 15 in the chuck 2 which convert the linear force to a radial force for radial movement of a plurality jaw slides 16, in unison, to grip the workpiece 3. This linear force is imparted to the draw tube 5 by the conventional rotating hydraulic cylinder 7.
The hydraulic cylinder 7 (FIG. 4) is of conventional design and composed of two sections, a stationary section or stator 17 and a rotating section or rotor 18. An internal bore 19 extends through the spindle 4, stator 17 and the rotor 18 and receives the draw tube 5 within the rotor 18 where it is threadably connected to the piston 8. The piston 8 is axially movable about the periphery of plastic liner 14 within the rotor 18 in accordance with hydraulic pressure communicated to the piston surfaces through ports 20 and 21 contained in the stator 17 and defines a portion of the bore 19. Extending from the stator 17 is a rotor extension 9 which is supported by a plurality of cam rollers 22 (only one of which is shown in FIG. 3) which are in turn supported by an outboard support assembly 23. The rotor extension 9 terminates beyond the support assembly 23 and is capped on its end by a quick disconnect coupling 10 and rotary union 11.
As shown most clearly in FIG. 3, quick disconnect coupling 10 is designed to facilitate quick and convenient capping and uncapping of the rotor extension 9. The coupling 10 has a body 24 circumscribed by a collar 25. The body 24 has an enlarged end portion 24a with an outside diameter of predetermined dimension and a reduced outside pilot diameter on its inner portion 24b adjacent the outboard support assembly 23. The enlarged diameter about portion 24a, adjacent the rotary union 11, forms a shoulder 26 which is abutted by a compression spring 27 circumscribing the pilot diameter of the inner portion 24b of the body 24. The collar 25 in turn circumscribes the spring 27 and the pilot diameter 24b, the former being contained within a relief portion 28 in the collar 25. The collar 25 is axially slidable upon the body 24. This axial movement is limited in the inward direction, toward the support assembly 23, by a retaining ring 29 mounted on the body 24 and in the outward direction by the shoulder 26 formed by the end portion 24a of the body 24. The collar 25 is biased inwardly toward the retaining ring 29 by the compressive force of spring 27 which abuts the shoulder 26 formed at the edge of relief portion 28. The pilot diameter of the body 24 also has a series of tapered holes 30 which align with an annular locking groove 31 on the periphery of the stator extension 9. When the coupling 10 is in its locked capped position a ball 32 fitted into each of the holes 30 extends into the annular locking groove 31. The diameter of the balls 32 and the holes 30 are matched such that the clearance provided by the end of tapered hole 30 adjacent the stator extension 9 is less than the diameter of ball 32 but large enough to permit a spherical sector of the spherical ball 32 to extend into the annular locking groove 31 on the periphery of stator extension 10. The balls 32 are retained in the holes 30 by the collar 25. An annular relief groove 33 formed in collar 25 is positioned such that axial movement of the collar 25 upon the body 24 against the force of spring 27 aligns the groove 33 with the series of holes 30 to permit the balls 32 to clear the corner 34 of the annular locking groove 31. Axial movement between the body 24 and the stator extension 9 is then possible and the entire quick disconnect coupling 10 may be removed to uncap the stator extension 10.
The rotary union 11 joins the rotating body 24 of quick disconnect coupling 10 to the nonrotating fluid supply pipe 12. The union 11 has a fixed body portion 11a and a rotor 11b supported by the bearings 11c within the body 11a. The rotor 11b extends to the coupling 10 where it is threadably received by the body 24a. The supply pipe 12 is threadably connected to the body 11a of rotary union 11 on its upper end portion 12a and extends through a slot 35 within a block 36 secured to the outboard support assembly 23 by suitable means, e.g., screws. The supply pipe 12 has at least two and preferably three distinct sections. The upper end portion 12a is formed with a non-metallic material such as plastic while the adjacent section 12b is formed of a metallic material. A proximity switch 37, attached to the side of block 36, is thus activated by the proximal positioning of supply pipe portion 12b but not by portion 12a. Consequently, proximity switch 37 will not be activated when quick disconnect coupling 10 is in its uncapped condition and rotary union 11 is rested upon block 36. A signal resulting from activation of the proximity switch, however, is suggestive of the proper capped positioning of coupling 10. The remaining portions of pipe 12 beyond section 12b is preferably constructed of flexible hosing in order to accomodate the movement of rigid portions 12a and 12b. It should also be apparent that rigid portions 12a and 12b, which extend through slot 35 in block 36 may additionally serve as an anti-rotation bracket for the body 11a of rotary union 11. Also secured to the outboard support assembly 23 is an electrical porting valve 52 (FIG. 7). The valve 52 provides a means for automatically controlling the flow of pressurized air prior to entry into fluid supply pipe 12.
Referring now to FIGS. 5 and 6, a fibrous brush bushing 41, having an internal bore 42, is circumferentially positioned in the channel 13 and fitted within the chuck 2. A forest of closely spaced bristles 43 is embedded in a cylindrical brush base 44 and extends radially inward toward the axial center of the channel 13. The brush base 44 is fitted within an adapter 45 which is threadably connected to the plastic liner 14. A shoulder 46 is formed at one end of the adapter 45 to prevent axial movement of the brush base 44 in a direction toward the chuck jaws 16. The opposite end of brush base 44 is abutted by a disc spacer 47 which prevents axial movement of the brush 41 in a direction away from the jaws 16. The internal bore 42 of bushing 41 forms a portion of the channel 13 and has a cross-sectional shape adapted to circumscribe the workpiece 3. The bristles 43 are flexible and readily conform to the surface contours of a wide range of workpiece shapes. The brush 41 fits closely around the workpiece 3 and cooperates therewith to restrict the flow of air from the channel 13. A tortuous labyrinth flow path around the workpiece 3 is thus provided through the forest of individual bristles 43. However, whenever the brush 41 interfaces the workpiece for any substantial distance, wide variances in the fluid backpressure will result between the conditions of workpiece presence and absence. The use of a brush 41 is particularly well suited for workpieces of rough and irregular surfaces, as for example hot rolled steel, as it will readily adapt to irregular surfaces and still resist rupture and tearing from rough scales on the surface.
In operation, the pressurized fluid such as compressed air is directed into fluid supply pipe 12. The air then flows through the rotary union 11, capped quick disconnect coupling 10, stator extension 9, rotating hydraulic cylinder 7 and draw tube 5. The flow of fluid from the draw tube 5 to the ambient atmosphere is through one of two alternate paths. If the channel 13 through the center of brush 41 is vacant, fluid flow will pass freely through this channel 13 to the atmosphere. If, however, the portion of channel 13 through brush 41 is occupied by a workpiece 3 the brush 41 would then surround the workpiece and force the flow through the forest of fibers of brush 41. Due to the variance in flow resistance between the two alternate paths, the backpressure of the air adjacent brush 41 may be utilized to detect the presence of work stock at this location. The brush 41 is preferably in close proximity to the work gripping members 16 of the chuck 2 in order that a minimum remnant will result. It is possible, however, to locate the brush 41 a greater distance from this critical location with increased remnant. Alternatively, if the machine 1 is operated by a computer numerical control system, a counter may be utilized to signal the number of permissible incremental workstock advances to insure sufficient chucking stock with known incremental advances and brush location distances.
A pneumatic circuit for the stock sensing device of the present invention is shown diagramatically in FIG. 7. A compressor 48 provides a source of pressurized air which is passed through a filter and dryer 49, a lubricator 50 and pressure regulator 51. An automatic porting valve 52 controls and the air flow adjacent the pressure regulator 51. If the valve 52 is in the open position, the air flows into the supply pipe 12 and through the channel 13 to the location of brush 41. The backpressure is sensed at location 54 with an in-line pressure switch 53. This pressure reading is then used to generate a signal, indicative of the absence or pressure of stock, at location 54 and used to control function of the turning machine 1.
The diagrammatic illustration of FIG. 8 shows a control circuit which might be used for the turning machine 1 and the pneumatic circuit of FIG. 7. An external signal generated from the bar feeder pulling attachment, or more typically from a numerical control tape program, closes contacts 56 and indicates that bar stock has been advanced. This is a command signal that the test for sufficient chucking stock should occur. At this time, the normally closed pressure switch 53a should be closed and coil CR-A energized, as the air supply through air supply valve 52 has not yet been activated. If, however, the pressure switch 53a is open, signalling a deflective or improperly installed switch, the coil CR-A will not be activated. This latter condition permits current to flow through normally closed contacts A-CR and 2-TR for energization of coil CR-B and an indicating light signalling a fault or defect in the pressure switch 53a. This condition prevents further sequencing and remains locked in the system until reset externally by a push botton (not shown) associated with normally closed reset contacts 57. This fault condition may also result from a failure to position proximity switch 37 properly in a similar manner, i.e., the closure of contacts D-CR through the non-activation of coil CR-D.
If pressure switch 53a is closed, coil CR-A will be activated. This activation, coupled with the activation of coil CR-D, achieved by approximating the closed capped position of coupling 10, permits energization of timer TR-2 so long as no fault signal flows through coil CR-B. This condition permits sensing system to operate activates the air supply by energizing solenoid 52a contained with valve 52. After a small time delay set by timer TR-2 to allow for backpressure to be built up, timed switch 2-TR is closed and the pressure switch 53a is examined once again.
Whenever the length of stock is insufficient to restrict air flow through brush 41 to maintain a predetermined backpressure, coil CR-A will remain activated and coil CR-C will be activated, along with its associated indication light signalling the absence of sufficient chucking stock. This condition is also locked into the circuit until reset by an external push button associated with normally closed reset contacts 58. When the backpressure does exceed this predetermined level, contacts A-CR, in series with coil CR-C, are opened and current is diverted to timer TR-3 through pressure switch 53b, the latter switch closing at this same predetermined level of backpressure. After a preset time delay in timer TR-3, time switch 3-TR is opened deactivating solenoid 52a and resetting timer TR-2. Additionally, an output signal through timer TR-3 is sent to the external source holding contacts 56 and thus removes the command signal for activation of the sensing device until subsequent advancement of the stock.
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An apparatus utilizes fluid pressure measurements to sense sufficient chucking stock for a chuck with work gripping surfaces. A flexible seal cooperates with a workpiece at a location proximal to the chuck jaws to restrict flow of a pressurized fluid. Flow resistance varies at this location with the presence or absence of sufficient chucking stock. A pressure switch senses the resulting fluid backpressure which varies with the resistance of the flow path and generates a signal indicative of the presence or absence of sufficient chucking stock which is used to control functions of a machine tool.
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TECHNICAL FIELD
This invention relates to highly reliable seals for remote oil wells that are hard to maintain. More specifically, this invention concerns redundant, self monitoring seals for high speed rotating shafts used with progressive cavity type oil well pumps.
BACKGROUND OF THE INVENTION
This invention is an improvement to an earlier oil pump shaft seal described in patent application Ser. No. 08/430,894, filed Apr. 27, 1995, by the same inventor, now abandoned and the teachings of that earlier patent are incorporated herein by reference.
Prior art seals for oil wells used a rope packing wrapped about the shaft and impregnated with grease which had to be routinely maintained by tightening a compression nut above the packing material so as to squeeze it more tightly against the pump shaft. This wears out quickly. My above referenced abandoned application disclosed a seal which utilizes a carbon and graphite filled polytetrafluoroethylene (PTFE) material that bears against a very hard and smooth sleeve, which sleeve is slipped over the pump drive shaft and sealed and locked thereto. The sleeve is prepared by flame spraying a powdered metal alloy onto the sleeve and then machining it to the necessary smoothness to withstand the leakage of the corrosive and poisonous gas found in many oil reserves. To allow this precision sealing surface to withstand the movement of the long, often unbalanced, drive shaft, a bearing is positioned as close as possible to the PTFE seal material so as to keep the sleeve stationary where it passes through the seal. It has been found that this seal design has no gas leakage and meets environmental regulations.
Today, many oil wells are located in remote regions, hundreds of miles from service facilities. In addition, these wells may produce only marginal quantities of oil. It is not economically viable to have operators on hand to monitor each of these remote, low yield wells for proper operation, as was common in the past where hundreds of wells operated side by side in vast oil fields above extensive oil reserves. Improved communications technologies allow these remote wells to be monitored automatically with sensors and measuring instruments on the well to keep track of such factors as pumping speed, oil flow, contamination, and failures. The information may then be transferred by phone line, or even satellite link, to a central maintenance facility so that repair operators can be dispatched if needed. The present invention provides a shaft seal that can operate remotely, monitor itself for failure, communicate the failure to the central repair facility, and also contain the failure until repair crews arrive, thus meeting stringent environmental regulations relating to the leakage of noxious gases into the air.
STATEMENT OF THE INVENTION
Briefly, the present invention incorporates a secondary or backup seal. This secondary seal is also located very close to the support bearing to protect the precision sealing surface. Normally the operating pressures of the well do not reach the secondary seal as they are contained by the primary seal. Hence, the secondary seal is not stressed and does not wear out. In the event of leakage past the primary seal, the secondary seal takes over the sealing function until repairs are made.
Between the primary and secondary seals, this invention incorporates a connecting port to sense any pressurized fluids or gases which would indicate a leak in the primary seal. The port connects to a pressure detector which, in turn, signals the failure through a suitable remote communications link using telephone or satellite technologies. Thus, the seal system monitors itself for failure and communicates any maintenance needs to a central repair office and also contains leaks for a sufficient time to allow the repairs to be scheduled at a convenient and economic time. Other benefits and advantages will become apparent from the following detailed description and the drawing referenced thereby.
BRIEF DESCRIPTION OF THE DRAWING
The drawing schematically shows the dual primary and secondary seal system in section, except for the drive shaft, so as to best reveal the configuration of the components within the oil well head sealing including the pressure detecting port.
DETAILED DESCRIPTION OF THE INVENTION
In the drawing, a drive head 10 is shown at the top. Drive head 10 is a standard design utilizing gears or belts to transfer rotational motion from a motor to a rod or drive shaft 12. Drive shaft 12 turns about its central axis and extends downward through a production tube or casing 14 to a progressive cavity pump 16. Pump 16 is a superior type of pump in which the drive shaft spins about its axis and rotates a down hole rotor. The rotor has a helical shape on the outside that engages an elastomeric stator with a helical shape on the inside surface so as to form cavities which progress upward, from the suction to the discharge end of the pump, carrying oil therein. These pumps are more reliable, contaminant tolerant, and lower in cost. Pump 16 lifts the oil upwards through casing 14, to a tee fitting somewhere below the seal structure, which tee is not shown in the drawing. At the tee, the oil is directed to a storage facility. However, the highly pressurized oil will also rise up inside tube 14 and bear against the primary seal bottom. It has been very hard to contain the oil at the top of the casing in the prior art because the oil is under high pressure, it usually contains salt water, sand, corrosive fluids and gases, and the packings around the rotating drive shaft need to be not too tight or else large amounts of energy are required to rotate shaft 12. In the prior art, a small amount of leakage is tolerated. A worker responds to excessive leaking by squeezing the packing a bit tighter with a compression nut above the packing. As the packing wears away, additional packing material is added to the stuffing box that surrounds the rotating shaft 12. However, this approach is impossible for remotely located wells that produce smaller quantities of oil where it is simply uneconomical to have a worker constantly watching the well head.
The drive shaft 12 is surrounded by a sleeve 20. Sleeve 20 is locked and sealed to pump shaft 12 with a cap 22 Sleeve 20 is flame sprayed with a powdered metal alloy called Colmonoy #6 so as to deposit a surface buildup of molten metal alloy. After cooling, the sleeve is machined to a tolerance of +0.000"and -0.002" on the sealing surface. A 6-8 rms surface finish is produced. The Colmonoy #6 alloy permits this accuracy and also affords a 60-65 Rc hardness for long wear. The Colmonoy #6 alloy is virtually impervious to the corrosive hydrogen sulfide gas found in many oil reserves and is also resistant to sand abrasion, arsenic and other metal buildups, and salt water corrosion.
Sleeve 20 extends downward through a self-aligning spherical ball or roller bearing 24. Shaft 12 may be thousands of feet long and out of balance in unpredictable ways. Hence, shaft 12 can whip and vibrate quite violently, with complex motions, at various frequencies. The progressive cavity pump may also add vibrations of its own due to its helical spinning configuration. This whipping exceeds the elastic response time of the PTFE seal material and could therefore generate gas leakage and seal wear. Bearing 24 is located as close as possible to the seals and holds shaft 12 and sleeve 20 in place, preventing sideways movement of sleeve 20 at the seal locations.
Bearing 24 is supported in a bearing housing 26 and bears against the sleeve 20 to hold it in place. A secondary seal housing 28 is threaded onto housing 26 with threads 30. Bearing housing 26 is itself threaded onto a primary seal housing 32 with threads 34. Contained within primary seal housing 32 is a PTFE seal 36 filled with graphite or carbon so as to be self lubricating. Seal 36 has a larger diameter bevel 38 at the top to locate it in the bore. Seal 36 is supported from above, so as to resist well pressures, by an inward extending flange 40 on bearing housing 26. Seal 36 is sealed to the bore by one or more o-rings 42. An encircling garter spring 43 urges the lower skirts 45 of seal 36 radially outward and inward. Also, well pressure tends to force skirts 45 radially outward and inward as well.
A problem with progressive cavity pumps is that, when the pumps are turned off, the column of oil falls back down the pipe, causing the rotor to spin backwards, and also forming a vacuum above the oil column that sucks the lubrication out of the seal packing. The spinning dry seal may be overheated, burned, and glazed. Since the PTFE material is self lubricating, and resistant to very high temperatures, it can withstand the backspin of shaft 12 when the well is shut down and the column of oil drops back down the casing 14. However, to better resist the vacuum, seal 36 has a upwardly slanted lip 44 that will be pulled more tightly against sleeve 20 when a vacuum is present beneath lip 44 to better seal against grease being sucked out of bearing 24.
A bronze bushing 46 supports the bottom end of sleeve 20 and locates shaft 12 to minimize whipping and vibration. A secondary seal 50, similar in design to primary seal 36, is positioned within secondary seal housing 28.
Secondary seal 50 is isolated from pressure and wear as long as primary seal 36 is properly functioning. If primary seal 36 fails, the grease packing within bearing housing 26 will become pressurized and forced up against secondary seal 50. Secondary seal 50 now takes over the sealing function until repairs are made.
To detect and signal the failure of the primary seal, a pressure detector 52 is connected with a suitable tube, indicated in the drawing by a dashed line 54, to a pressure port 56 drilled in the side of bearing housing 26. Port 56 communicates with the space between the bearings that becomes pressurized if pressure starts leaking past primary seal 36. Detector 52 is connected to a suitable remote communications link 58. Because of the high quality of the secondary seal 50, the replacement of the primary seal 36, as signaled by link 58, may be scheduled at a convenient time.
Because of the variations possible within the spirit and scope of the invention, limitation only in accordance with the following claims is appropriate.
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A seal system for an oil well head, wherein the shaft rotates about its axis to drive a progressive cavity type pump. Primary and secondary polytetrafluoroethylene seals surround a sleeve that encircles the shaft. Pressure detectors connect to the space between the seals to detect leaks past the primary seal and signal a remote repair facility. The secondary seal assumes the sealing function while repairs are scheduled.
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[0001] This application claims priority to U.S. Provisional Application No. 62/140,722 filed on Mar. 31, 2015, the entirety of which is herein incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to a method for preparing a thermoplastic biodegradable resin (e.g., polylactic acid or PLGA) containing a powdery drug (e.g., inorganic particles for bone formation, an anticancer agent, or an antibiotic) as a spinning solution for electrospinning.
[0003] The present invention further relates to a method for manufacturing biodegradable fibers by electrospinning using a spinning solution for electrospinning prepared by the above method.
[0004] The present invention further relates to a method for efficiently collecting biodegradable fibers prepared by the above method as non-woven fabric or cotton.
[0005] The present invention relates to an in-vivo locally implantable sustained-release agent including a bioabsorbable cotton-like material manufactured by the above manufacturing method; and usage thereof (treatment method).
[0006] The drug-containing bioabsorbable cotton-like material according to the present invention has excellent local sustained releasability and is quickly absorbed and broken down by the body after the release of a medicinal ingredient, and is therefore extremely effective as a drug formulation other than an orally administered agent, such as a long-acting injection (depot preparation) or an in-vivo implantable drug formulation.
BACKGROUND ART
[0007] Among drug administration routes, oral administration accounts for about 60%, which is the most widely used administration route. However, peptide/protein drugs have recently increased, which are polymeric drugs that cannot be expected to have adequate absorbability and stability by oral administration. Further, in the future, gene/nucleic acid drugs having higher molecular weights are expected to be clinically used. Further, when orally administered, a drug is absorbed from the small intestine and flows throughout the body via the bloodstream. For this reason, oral administration is not suitable for drugs required to have locality and sustained releasability.
[0008] As administration routes other than oral administration, there are various administration routes such as nasal administration, pulmonary administration, ocular instillation, rectal administration, transdermal administration, and administration by injection. Injections are used next to orally administered agents. However, among injections, intravenous drip injections cannot often be expected to have the effect of localized sustained release as in the case of oral administration. Further, injections are quickly absorbed but often have a problem with the persistence of medicinal effect after administration.
[0009] On the other hand, long-acting injections (depot preparations) have also been developed. Long-acting injections are injections produced so that their medicinal effects last for several days to several months per administration. Such long-acting injections are often used as hormonal drugs, and applied in the form of oil-based injections or suspended injection. They are applied also to antipsychotic agents that are likely to have a problem with continuous oral administration. They are percutaneously or intramuscularly injected and are expected to have a sustained effect even after administration, but it is difficult to allow a drug to locally act only on a target site (tissue).
[0010] As a drug formulation that sustains the effect of a physiological active substance for a long time, microspheres using a biodegradable polymer (multinuclear microcapsules) have also been researched (JP-A-6-211648). Microspheres usually refer to a spherical preparation having a particle diameter of about several micrometers, and those having a particle diameter of 1 μm or less are sometimes called nanospheres. Microspheres satisfy the localized sustained releasability of a drug and locality, but are suspended in a liquid on the condition that they are administered by injection (e.g. subcutaneous injection). Therefore, microspheres have a problem with drug stability (the drug is dispersed), and therefore their research and development are underway even now.
[0011] In order to prevent the dispersion of a drug and maintain stability, a drug formulation using a hydrophobic polymer (silicone that is a non-biodegradable polymer) as a carrier has also been studied (JP-A-2001-199879). In this case, the dispersion of a drug can be prevented, but there is a problem that the carrier is left in the body. There is no problem in applying the drug formulation to a site from which the drug formulation is relatively easily removed, such as a site under the skin, but implantation of the drug formulation in any site in the body has a risk.
[0012] On the other hand, in the field of bone regeneration materials, a method has been performed in which a material prepared by adding an osteogenic factor to fibers made of a biodegradable resin such as polylactic acid is implanted into a bone defect (U.S. Patent Publication No. 2011-000952). The biodegradable fibers are hydrolyzed by contact with body fluid after implanted in the body so that a drug contained in the biodegradable fibers is sustainably released and the biodegradable fibers are absorbed by the body with the lapse of time and disappear. Therefore, bone formation is effectively achieved while a burden on a patient is reduced.
[0013] Electrospinning is used as a method for manufacturing fibers from a biodegradable resin in the above-described method. In the electrospinning method, a spinning solution is extruded from a nozzle as fibers by an electrostatic attractive force generated in an electric field. Therefore, such a spinnable solution needs to be prepared.
[0014] In the field of bone regeneration materials, spinning solutions for electrospinning have heretofore been prepared by dissolving biodegradable resins using solvents.
CITATION LIST
Patent Literature
[0000]
PATENT LITERATURE 1: JP-A-6-211648
PATENT LITERATURE 2: JP-A-2001-199879
PATENT LITERATURE 3: U.S. Pat. No. 6,689,374
PATENT LITERATURE 4: U.S. Patent Publication No. 2011-0009522
PATENT LITERATURE 5: WO 2015/005205
Non-Patent Literatures
[0000]
NON-PATENT LITERATURE 1: Walsh et al. B-TCP bone graft substitutes in a bilateral rabbit tibial defect model. Biomaterials 29 (2008) 266-271
NON-PATENT LITERATURE 2: Obata et al. Electrospun microfiber meshes of silicon-doped vaterite/poly(lactic acid) hybrid for guided bone regeneration. Acta Biometatialla 6 (2010) 1248-1257
NON-PATENT LITERATURE 3: Fujihara et al. Guided bone regeneration membrane made of polycaprolactone/calcium carbonate composite nano-fibers. Biomaterials 26 (2005) 4139-4147)
NON-PATENT LITERATURE 4: Hench L L. Polak J M: Third-generation biomedical materials. Science 2002, 295: 1014-1017)
NON-PATENT LITERATURE 5: Weiss et al. Targeted expression of MYCN causes neuroblastoma in transgenic mice. The EMBO Journal Vol. 16 No. 11 pp. 2985-2995, 1997
NON-PATENT LITERATURE 6: Kishida et al. Midkine Promotes Neuroblastoma through Notch 2 Signaling. Cancer Res; 73 (4) 1318-1327, 2013
SUMMARY OF THE INVENTION
Technical Problem
[0026] It is therefore an object of the present invention to provide a drug formulation material that is capable of locally and sustainably releasing a drug at any site in the body, that has bioabsorbability, and that is absorbed and broken down by the body after sustained release of the drug.
Solution to Problem
[0027] As a method for locally administering a drug to an affected area, a method has been proposed (U.S. Pat. No. 6,689,374) in which a material obtained by adding a drug to biodegradable fibers is implanted in an affected area to sustainably release the drug. A spinning solution that can be used for electrospinning is prepared by first dispersing fine particles in water or a solvent and then uniformly dispersing the dispersion liquid in a solution prepared by dissolving a biodegradable resin to mix them. However, when a large amount of fine powder particles are contained, these fine particles cannot be easily uniformly dispersed in the spinning solution by such a method. Therefore, the biodegradable fibers have a small outer diameter and a short sustained release period.
[0028] The present inventors have intensively studied, and as a result have found that the above problem can be solved by 1) dissolving a biodegradable resin and a drug in a solvent to prepare a spinning solution and 2) spinning fibers from the spinning solution by electrospinning. Based on the finding, the present inventors have successfully developed a drug formulation material that includes a fibrous material having a large diameter and has a very high sustained release effect.
[0029] More specifically, the present invention includes the following aspects [1] to [20].
[0030] [1] A bioabsorbable cotton-like material having a cotton- or nonwoven fabric-like structure, including a fibrous material that includes a drug and a biodegradable resin and has an average outer diameter of 1 μm or more but 150 μm or less, preferably 10 μm or more but 150 μm or less, more preferably 30 μm or more but 110 μm or less, even more preferably 60 μm or more but 110 μm or less.
[0031] [2] The bioabsorbable cotton-like material according to [1], wherein the fibrous material has an average molecular weight of 50000 or more but less than 1000000, preferably 50000 or more but less than 500000, more preferably 60000 or more but less than 400000.
[0032] [3] The bioabsorbable cotton-like material according to [1], whose bulk density when dried or hydrated is 0.01 g/cm 3 to 0.1 g/cm 3 , more preferably 0.01 g/cm 3 to 0.05 g/cm 3 .
[0033] [4] The bioabsorbable cotton-like material according to any one of [1] to [3], wherein the biodegradable resin is PLGA or a copolymer thereof.
[0034] [5] The bioabsorbable cotton-like material according to any one of [1] to [4], wherein the drug is an anticancer agent.
[0035] [6] The bioabsorbable cotton-like material according to any one of [1] to [5], which has been subjected to sterilization treatment.
[0036] [7] A method for manufacturing a bioabsorbable cotton-like material, characterized by including:
[0037] step 1) dissolving a biodegradable resin and a drug in a solvent to prepare a spinning solution; and
[0038] step 2) spinning fibers from the spinning solution by electrospinning.
[0039] [8] The method for manufacturing a bioabsorbable cotton-like material according to [7], wherein in the step 2), fibers are spun by electrospinning by applying a voltage between a nozzle part provided on a solution extrusion side and a plate placed in an ethanol bath provided on a collector side to deposit a bioabsorbable cotton-like material in the ethanol bath to form a bioabsorbable cotton-like material having a cotton-like three-dimensional structure.
[0040] [9] The method for manufacturing a bioabsorbable cotton-like material according to [7] or [8], further including step 3) of sterilization treatment.
[0041] [10] The method for manufacturing a bioabsorbable cotton-like material according to any one of [7] to [9], wherein the biodegradable resin is PLGA or a copolymer thereof, and the solvent is chloroform or dichloromethane.
[0042] [11] The method for manufacturing a bioabsorbable cotton-like material according to any one of [7] to [10], wherein the drug is an anticancer agent.
[0043] [12] A method of treating or preventing a disease in the patient, comprising:
[0044] 1) implanting the bioabsorbable cotton-like material according to [6] in a body of patient;
[0045] 2) sustainably releasing the drug from the bioabsorbable cotton-like material; and
[0046] 3) treating or preventing the disease in the patient by an effect of the sustainably released drug.
[0047] [13] The method according to [10], wherein the bioabsorbable cotton-like material according to [6] is implanted by laparotomy.
[0048] [14] The method according to [12], wherein the bioabsorbable cotton-like material according to [6] is implanted by a minimally invasive medical procedure using an injector.
[0049] [15] The method according to [12], wherein the drug is an anticancer agent, and the disease is cancer.
[0050] [16] The method according to [15], wherein the patient has been subjected to resection of cancer tissue or cancer cells.
[0051] [17] The method according to [15] or [16], wherein the cancer is malignant bone tumor.
[0052] [18] A kit for use in the method according to [12] or [13], including the bioabsorbable cotton-like material according to [6].
[0053] [19] A kit for use in the method according to [14], including an injector and the bioabsorbable cotton-like material according to [6].
[0054] [20] The kit according to [19], wherein the bioabsorbable cotton-like material according to [6] is contained in the injector.
[0055] The “biodegradable resin (biodegradable polymer)” is generally defined as a “resin that can be used in the same manner as common plastics under normal use conditions but is broken down after use and finally converted into carbon dioxide and water and returned to nature”. In the present invention, the biodegradable resin means a resin (polymer) broken down by the bodies of humans and non-human mammals (including domestic animals such as cattle and pigs and companion animals such as dogs and cats). The biodegradable resin is not particularly limited, but may be a natural polymer such as cellulose or starch or any one of several types of biodegradable synthetic polymers having excellent biocompatibility and adjusted biodegradation rate and mechanical strength. Examples of the synthetic polymers include: polyglycolic acid (PGA) and polylactic acid (PLA) (poly-L-lactic acid: PLLA, poly-D-lactic acid: PDLA); copolymers thereof; [polylactic acid-polyglycolic acid copolymer (poly(lactide-co-glycolide) copolymer) (PLGA)]; and polydioxanone (PDS). In the case of PLGA, the ratio of monomers PLA and PGA can be changed depending on a desired degradation rate. The ratio may be PLA: PGA=90:10, 85:15, 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60, 35:65, 30:70, 25:75, 20:80, 15:85, or 10:90.
[0056] The “solvent” is not particularly limited as long as it is a volatile solvent that has low solubility in water and is a good solvent for polymers. Examples of such a solvent include chloroform, methylene chloride, and carbon tetrachloride. Alternatively, a mixed solvent of such a solvent and a solvent compatible therewith (e.g., ethyl ether or ethyl acetate) may be used. The solvent is preferably one that does not impair the activity of the “drug”.
[0057] The “drug” means an inorganic or organic material that can be administered to a human body by adding to biodegradable fibers and that exerts its activity when the biodegradable fibers are implanted in a human body.
[0058] Examples of the drug include, but are not limited to, an anticancer agent, an antibiotic, a polypeptide having a physiological activity (e.g., influenza vaccine or insulin), an antipyretic agent, an analgesic, an immunostimulating agent, an immunosuppressive agent, an antiinflammatory agent, a cough suppressant, an antiepileptic agent, an antihistamine, an antihypertensive diuretic, an antidiabetic agent, a muscle relaxant, an antiulcer agent, an antidepressant, an antiallergic agent, an antianginal agent, an arrhythmia therapeutic agent, a vasodilator, an anticoagulant, a hemostatic agent, an antitubercular agent, a narcotic antagonist, and a hormonal agent. The “drug” may include not only drugs in the pharmaceutical field but also drugs in the cosmetics field (e.g., vitamins, placenta, and hyaluronic acid). The drug is preferably resistant to the “solvent” described above.
[0059] The “bulk density” is measured with reference to JIS L 1097 of cotton.
[0060] The “electrospinning (ES)” refers to a method for manufacturing microfibers, in which a high voltage is applied between a polymer solution contained in a syringe and a collector electrode so that the solution extruded from the syringe is electrically charged and adhered to the collector as microfibers.
[0061] The “minimally invasive medical procedure” refers to a procedure in which, in surgery, not only the size of a surgical cut on the body but also a physical and mental burden on a patient is smaller as compared to a conventional procedure (e.g., laparotomy). Endoscopic surgery corresponds to the minimally invasive medical technique.
[0062] The “injector” (inserter) refers to a device that is percutaneously inserted into the body under X-ray fluoroscopy or the like to leave a drug or medical instrument contained therein in the body. An endoscope or the like may be connected to the injector.
[0063] Examples of the method of “sterilization treatment” include radiation sterilization (gamma rays, electron beams), ethylene oxide gas sterilization, and high-pressure steam sterilization. In the present invention, radiation sterilization with γ rays is preferably used. When radiation sterilization with γ rays of 25 kGy to 35 kGy is performed, the average molecular weight decreases (60000 to 100000).
Advantageous Effects of Invention
[0064] The present invention is effective as a method for manufacturing biodegradable fibers carrying a drug from a biodegradable resin containing the drug by electrospinning.
[0065] The biodegradable fibers can provide a drug formulation material that is capable of locally and sustainably releasing a drug at any site in the body, has bioabsorbability, and is absorbed and broken down by the body after sustained release of the drug.
[0066] Further, implantation of the drug formulation in a patient can produce a therapeutic/preventive effect to enhance QOL (Quality of Life).
BRIEF DESCRIPTION OF DRAWINGS
[0067] 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.
[0068] FIG. 1A is a SEM photograph of fibers (40TCP-30SiV-30PLLA) spun by a method described in Reference Example 1.
[0069] FIG. 1B shows fibers spun from a solution having the same mixing ratio as in Reference Example 1 but not subjected to kneading with a kneader.
[0070] FIG. 2 is a SEM photograph of fibers (70TCP-30PLLA) spun by a method described in Reference Example 2.
[0071] FIG. 3 shows fibers of PLLA 100% spun using an electrospinning device in Reference Example 3.
[0072] FIG. 4 shows the configuration of an electrospinning device used in the present invention.
[0073] FIG. 5 is a SEM photograph of fibers (30-fold amount of carboplatin-PLGA) spun in Example 1.
[0074] FIG. 6 Methods for calculating a compression rate and a recovery rate
[0075] FIG. 7 Results of Example 2
[0076] FIG. 8 Shapes
[0077] FIG. 9 Results of Example 3
[0078] FIG. 10 Results of Example 4: Sustained-release behavior of carboplatin from a cotton-like carrier Carboplatin was sustainably released over 168 hours.
[0079] FIG. 11 Results of Example 5: Images of a dissected mouse that developed cancer and died at 8 weeks of age.
[0080] There was a very large tumor enough to fill the gap between the left and right kidneys.
[0081] FIG. 12 Results of Example 5: Images of a dissected mouse (F166) implanted with the cotton-like carrier and euthanized at 12 weeks of age No tumor was observed. The cotton-like carrier remained.
[0082] FIG. 13 Results of Example 5: Changes in body weights of mice after implantation The body weights of mice implanted with the cotton-like carrier increased similarly to those of sham surgery mice (implanted with a cotton-like material made of only a polymer and carrying no anticancer agent), suggesting that side effects of an anticancer agent did not occur.
[0083] FIG. 14 Results of Example 5: Abdominal ganglia was excised and fixed with formalin to be histologically evaluated.
[0084] FIG. 15 Results of Example 5: H&E stained sections On the left side of the aorta (indicated by an yellow arrow), scarring of fibroblasts (having an elongated nuclear shape) is observed which is not usually observed.
[0085] FIG. 16 Results of Example 5: H&E stained sections Calcified portions (circular portions that look like missing portions: indicated by blue arrows) are observed.
[0086] FIG. 17 Results of Example 5: A mouse to which the same amount of carboplatin as contained in the cotton-like carrier was directly intraperitoneally administered The mouse moved slowly and trembled, and its lower abdomen was obviously thin. The intestines were necrosed and became dysfunctional. Ingested diet was collected in the stomach, but the small and large intestines contained nothing.
[0087] FIG. 18 Results of Example 5: A mouse to which PBS was directly intraperitoneally administered. The behavior and appearance of the mouse were both normal. There was no abnormality in the internal organs.
DESCRIPTION OF EMBODIMENTS
[0088] In one embodiment of the present invention, a small amount of a drug is added to and mixed with a solution obtained by dissolving a biodegradable resin in a solvent to prepare a spinning solution, and fibers are spun by electrospinning using the spinning solution. Polylactic acid or PLGA can be dissolved in a solvent to prepare a spinning solution for electrospinning. Therefore, a spinning solution prepared by mixing a very small amount of a drug into a solution of polylactic acid or PLGA can be spun into fibers by electrospinning.
[0089] In one embodiment of the present invention, a syringe of an electrospinning device is filled with the solution obtained above as a spinning solution to extrude the solution from a nozzle as yarns. The yarns extruded from the nozzle fly in a parabola toward a grounded electrode as a target and are deposited on a collector. The collector is formed in a net shape and contained in a container filled with an ethanol solution. The yarns extruded from the nozzle enter the surface of the ethanol solution and precipitate in the solution at their entry points. The precipitated yarns are deposited on the collector and form a nonwoven fabric- or cotton-like material. The “cotton-like material” refers to a material that can be deformed by hands (shape processability); that can be torn into pieces and again put the pieces together after tear (size processability); that can be restored after compression (elastic force); and that can be squeezed by hands to adjust its hydration amount.
[0090] In one embodiment of the present invention, the bottom surface (about 15 cm×25 cm) of a collector of an electrospinning device is used as an electrode plate when fibers are extruded from a nozzle. The collector does not use an ethanol solution. This method makes it possible to deposit fibers on the collector in the form of non-woven fabric.
EXAMPLES
[0091] The present invention may be described in more detail with reference to the following examples, comparative examples, and reference examples, but is not limited to these examples.
<Reference Example 1> PLLA, β-Tricalcium Phosphate, and Si-Containing Vaterite Phase Calcium Carbonate (40TCP-30SiV-30PLLA)
[0092] Step 1
[0093] Drugs and polylactic acid are mixed and kneaded by a kneader. The kneader is preheated to a set temperature of 170 to 190° C., and then 15 g of poly-L-lactic acid pellets (PURAC PL24, molecular weight: 200000 to 300000, melting point: 175 to 185° C.) are fed into the kneader and heated and kneaded at a set temperature of 180° C. to 190° C. for about 4 minutes. Then, a powder obtained by mixing 20 g of β-tricalcium phosphate powder and 15 g of SiV powder is fed into the kneader, and the mixture is further kneaded at the same set temperature for about 10 minutes.
[0094] When heated at a set temperature of 180° C. to 190° C. of the kneader, the mixture can be kneaded by applying torque by the kneader in that state. Although the state of poly-L-lactic acid heated by the kneader is not exactly clear, the present inventors estimate that there are a melted part that has reached the melting point of poly-L-lactic acid and a part in a softened state on the verge of melting.
[0095] In the present invention, even when poly-L-lactic acid is heated but stays in a softened state without reaching a melted state, fine powder particles can be uniformly dispersed in the matrix resin as long as the matrix resin can be kneaded in a softened state by applying torque by the kneader.
[0096] The powder of β-tricalcium phosphate and the powder of SiV added later are mixed with poly-L-lactic acid by kneading so that the fine particles are uniformly dispersed in the poly-L-lactic acid resin. Although the dispersion state at the molecular level is not exactly clear, it can be considered, based on the findings of the present inventors and the like, that β-tricalcium phosphate and SiV are immobilized in polylactic acid as a matrix resin by the coordinate bond between the calcium ion of β-tricalcium phosphate and the carboxyl group of poly-L-lactic acid and the amido bond between an amino group included in SiV and the carboxyl group.
[0097] Step 2
[0098] A composite of the drugs and polylactic acid is prepared. Then, the obtained kneaded product of β-tricalcium phosphate, SiV, and poly-L-lactic acid is taken out of the kneader and allowed to stand at ordinary temperature for cooling. In this way, a composite lump of poly-L-lactic acid and the drugs is obtained.
[0099] Step 3
[0100] The composite lump obtained above is dissolved in a solvent (e.g., chloroform) to prepare a spinning solution whose poly-L-lactic acid concentration is about 10%. The dissolution of the composite lump in a solvent is performed by placing the composite lump in a container filled with chloroform and slowly rotating the composite lump using a magnetic stirrer for about 5 hours for stirring.
[0101] Step 4
[0102] A syringe (diameter: 15.8 mm, extrusion speed: 15 mL/h) of an electrospinning device (e.g., NANON manufactured by Mecc) is filled with the spinning solution prepared above, and fibers are extruded through a nozzle (syringe needle: 18 G) by applying a voltage of about 30 kV, and are deposited on a collector while the nozzle is moved a width of 200 mm at a speed of 40 mm/sec and the needle tip is cleaned at an interval of 2 minutes (*) (condition in chamber=temperature: 30 centigrade temperature or less; humidity: 50% or less; length from needle tip to device floor: 37 cm).
[0103] (*) The interval between automatic cleaning to remove the drop of solution formed at the tip of the needle.
[0104] As shown in FIG. 4 , in electrospinning, an electrode is provided on the collector side to guide yarns extruded from the nozzle toward the electrode. The collector is contained in a container filled with an ethanol solution, and the yarns guided from the nozzle toward the electrode fly in a parabola, enter the surface of the ethanol solution, and precipitate in the ethanol solution at their entry points. The precipitated yarns are deposited on the mesh of the collector formed in a net-like shape and form a cotton-like material. The yarns extruded from the nozzle during spinning are widely deposited on the surface of the collector by reciprocally moving the nozzle a constant distance at a constant speed on a rail, which is effective at increasing a collection rate.
[0105] Results
[0106] The average diameter of the fibers extruded from the nozzle by electrospinning was about 50 μm. The SEM photograph of the obtained fibers is shown in FIG. 1A . For comparative reference, FIG. 1B shows the result of an attempt to spin fibers by the electrospinning device from a solution prepared to have the same composition as in Reference Example 1 without the process of kneading by a kneader. At least fibrous material was obtained, but had a much larger diameter than fibers manufactured by electrospinning.
<Reference Example 2>β-Tricalcium Phosphate and PLLA (70TCP-30PLLA)
[0107] Step 1
[0108] β-tricalcium phosphate and poly-L-lactic acid (PURAC PL24, molecular weight: 200000 to 300000) are kneaded by a kneader.
[0109] The kneader is preheated to a set temperature of 170 to 190° C. for 3 minutes, and then 15 g of poly-L-lactic acid pellets are fed into the kneader and heated and kneaded at a set temperature of 180° C. to 190° C. for about 4 minutes. Then, 35 g of β-tricalcium phosphate powder is fed into the kneader, and the mixture is further kneaded at the same set temperature for about 10 minutes.
[0110] When heated at a set temperature of 180° C. to 190° C. of the kneader, the mixture can be kneaded by applying torque by the kneader in that state. The state of poly-L-lactic acid heated by the kneader is not exactly clear. The present inventors estimate that there are a melted part that has reached the melding point of poly-L-lactic acid and a part in a softened state on the verge of melting.
[0111] The powder of β-tricalcium phosphate added later is mixed well with poly-L-lactic acid by kneading, and is therefore uniformly dispersed in the poly-L-lactic acid resin. As for the dispersion state, the present inventors estimate that β-tricalcium phosphate is immobilized in polylactic acid as a matrix resin by the coordinate bond between the calcium ion of β-tricalcium phosphate and the carboxyl group of poly-L-lactic acid.
[0112] Step 2
[0113] A composite of β-tricalcium phosphate and polylactic acid is prepared.
[0114] Then, the obtained kneaded product of β-tricalcium phosphate and poly-L-lactic acid is taken out of the kneader and allowed to stand at ordinary temperature for cooling. In this way, a composite lump of poly-L-lactic acid and TCP is obtained.
[0115] Step 3
[0116] The composite lump of PLLA and β-tricalcium phosphate obtained above is dissolved in a solvent (e.g., chloroform) to prepare a spinning solution whose PLLA concentration is about 10 wt %. The dissolution of the composite lump in a solvent is performed by placing the composite lump in a container filled with a solvent (e.g., chloroform) and slowly rotating the composite lump using a magnetic stirrer for about 5 hours for stirring.
[0117] Step 4
[0118] A syringe of an electrospinning device is filled with the spinning solution. The spinning solution is extruded from a nozzle as fibers, and the fibers are deposited on a collector.
[0119] As shown in FIG. 4 , in electrospinning, an electrode is provided on the collector side to guide yarns extruded from the nozzle toward the electrode. The collector is contained in a container filled with an ethanol solution, and the yarns guided from the nozzle toward the electrode fly in a parabola, enter the surface of the ethanol solution, and precipitate in the ethanol solution at their entry points. The precipitated yarns are deposited on the mesh of the collector formed in a net-like shape and form a cotton-like material.
[0120] Results
[0121] The diameters of the fibers extruded from the nozzle by electrospinning were not stable as compared to the case of PLLA-βTCP-SiV described above, and were about 65 to 80 μm.
[0122] The SEM photograph of the obtained fibers is shown in FIG. 2 .
<Reference Example 3> PLLA 100%
[0123] FIG. 3 shows fibers spun by electrospinning from a biodegradable resin composed of 100% PLLA used in Reference Examples 1 and 2 under the same conditions.
[0124] It is expected that when the amount of a drug to be mixed is very small, similar fibers can be spun by electrospinning.
<Reference Example 4> PLGA and SiV (50SiV-50PLGA)
[0125] Step 1
[0126] A drug and PLGA are kneaded by a kneader.
[0127] The kneader is heated to a set temperature of 160 to 165° C. for 3 minutes, and then 25 g of PLGA pellets (molar ratio: 82:18, melting point: 130 to 140° C.) are fed into the kneader and heated and kneaded at a set temperature of 160° C. to 165° C. for about 4 minutes. Then, 25 g of SiV powder is fed into the kneader, and the mixture is further kneaded at the same set temperature for about 10 minutes.
[0128] When heated at a set temperature of 160° C. to 165° C. of the kneader, the mixture can be kneaded by applying torque by the kneader in that state. The state of PLGA heated by the kneader is not exactly clear. The present inventors estimate that there are a melted part that has reached the melding point of poly-L-lactic acid and a part in a softened state on the verge of melting.
[0129] Even when poly-L-lactic acid is heated but stays in a softened state without reaching a melted state, fine powder particles can be uniformly dispersed in the matrix resin as long as the matrix resin can be kneaded in a softened state by applying torque by the kneader.
[0130] The powder of SiV added later is mixed well with PLGA by kneading, and is therefore uniformly dispersed in the matrix resin. As for the dispersion state, the present inventors estimate that SiV is immobilized in polylactic acid as a matrix resin by the coordinate bond between the carboxyl group of PLGA and the calcium of calcium carbonate and the amido bond between the carboxyl group of PLGA and an amino group included in SiV.
[0131] Step 2
[0132] A composite of SiV and PLGA is prepared.
[0133] Then, the obtained kneaded product of SiV and PLGA is taken out of the kneader and allowed to stand at ordinary temperature for cooling. In this way, a composite lump of PLGA and a drug is obtained.
[0134] Step 3
[0135] The composite lump of PLGA and SiV obtained above is dissolved in a solvent (e.g., chloroform) to prepare a spinning solution whose PLGA concentration is about 13 to 15 wt %. The dissolution of the composite lump in a solvent is performed by placing the composite lump in a container filled with a solvent (e.g., chloroform) and slowly rotating the composite lump using a magnetic stirrer for about 5 hours for stirring.
[0136] Step 4
[0137] A syringe of an electrospinning device is filled with the spinning solution. The spinning solution is extruded from a nozzle as fibers, and the fibers are deposited on a collector.
[0138] In electrospinning, an electrode is provided on the collector side to guide yarns extruded from the nozzle toward the electrode. The collector is contained in a container filled with an ethanol solution, and the yarns guided from the nozzle toward the electrode fly in a parabola, enter the surface of the ethanol solution, and precipitate in the ethanol solution at their entry points. The precipitated yarns are deposited on the mesh of the collector formed in a net-like shape and form a cotton-like material.
<Comparative Example 1> Production Results of TCP-SiV-PLLA
[0139] The present inventors tried to produce fibers under the same conditions as in Reference Example 1 except that the ratio among PLLA, β-tricalcium phosphate, and Si-containing vaterite phase calcium carbonate was changed. The following Table 1 shows conditions under which fibers were successfully produced, and the following Table 2 shows conditions under which fibers were unsuccessfully produced.
[0000]
TABLE 1
Kneader
Mixing ratio
ES
wt %
Temper-
Concen-
PLLA
TCP
SiV
ature
Result
tration
Voltage
Result
70
0
30
180° C.
◯
8%
20 kV
◯
50
0
50
180° C.
◯
8%
20 kV
◯
30
60
10
180° C.
◯
10%
29 kV
◯
30
40
30
180° C.
◯
10, 8%
25 kV
◯
30
0
70
180° C.
◯
8%
20 kV
◯
[0000]
TABLE 2
Kneader
Mixing ratio
wt %
ES
PLLA
TCP
SiV
Temperature
Result
Concentration
Voltage
Result
Notes
20
0
30
180° C.
X
The power was spilled. The kneaded
product was very crumbly due to
unsuccessful kneading.
30
70
0
Without
NA
10 → 3%
15~30
X
The spinning solution only dripped and
kneading
therefore fibers did not fly.
30
0
70
Without
NA
10%
15~30
X
kneading
[0140] When the proportion of the polymer was 20 wt %, the proportion of the powder was too large to perform kneading. Further, when PLLA was directly dissolved in chloroform without the process of kneading, and a mixture of the solution and TCP or SiV was kneaded, the solution only dripped from the tip of the needle, and therefore spinning could not be performed.
<Comparative Example 2> Production Results of TCP-SiV-PLGA
[0141] The present inventors tried to produce fibers using PLGA (LG855S (manufactured by Evonik, PLLA:PGA=85:15)) instead of PLLA. The following Table 3 shows conditions under which fibers were successfully produced, and the following Table 4 shows conditions under which fibers were unsuccessfully produced.
[0000]
TABLE 3
Kneader
Mixing ratio
ES
wt %
Temper-
Concen-
PLGA
TCP
SiV
ature
Result
tration
Voltage
Result
50
0
50
165° C.
◯
10, 8%
25 kV
◯
50
50
0
165° C.
◯
8%
28 kV
◯
50
20
30
165° C.
◯
8%
28 kV
◯
30
40
30
165° C.
◯
8%
28 kV
◯
30
70
0
165° C.
◯
8%
25 kV
◯
165° C.
◯
8%
28 kV
◯
7%
25 kV
◯
6%
25 kV
Δ
30
0
70
165° C.
◯
8%
28 kV
◯
Δ: Slightly crumbly
[0000]
TABLE 4
Kneader
Mixing Ratio
wt %
ES
PLGA
TCP
SiV
Temperature
Result
Concentration
Voltage
Result
Notes
30
70
0
115° C.
X
PLGA was not melted due to low temperature,
and was therefore not mixed with TCP.
20
50
30
165° C.
X
10%
30 kV
X
Fibers were fine and brittle.
8%
28 kV
X
Fibers flew but were fine and brittle.
30
0
70
Without
NA
10 → 8%
15~30
X
The spinning solution only dripped and
kneading
therefore fibers did not fly.
[0142] When the proportion of the polymer was 20 wt %, the proportion of the powders was too large to perform kneading. Further, when the kneading temperature was low, the polymer could not be melted and kneaded, and when the process of kneading was omitted, fibers could not be spun.
<Example 1> PLLA or PLGA, Anticancer Agent (Carboplatin Powder, Etoposide Powder, Doxorubicin Hydrochloride Powder), and Antibiotic
[0143] Small amounts of an anticancer agent (carboplatin powder, etoposide powder, doxorubicin hydrochloride powder) and an antibiotic were mixed into a solution obtained by dissolving PLLA or PLGA in a solvent to prepare a spinning solution, and fibers were spun from the spinning solution by electrospinning.
Materials
[0144] Biodegradable resin: PLGA (LG855S (manufactured by Evonik, PLLA:PGA=85:15))
[0145] Carboplatin (cis-Diamine(1,1-cyclobutanedicarboxylato)platinum (II)) (CAS number: 41575-94-4, product code: C2043, Tokyo Chemical Industry Co., Ltd.)
[0146] Method
[0147] Step 1
[0148] First, 3 g of PLGA and carboplatin were dissolved in chloroform to prepare a spinning solution having a PLGA concentration of about 6 wt %. The amount of carboplatin was shown in the following Table 5. A syringe (diameter: 15.8 mm, extrusion speed: 15 mL/h) of an electrospinning device (e.g., NANON, MECC CO., LTD.) was filled with the prepared spinning solution. The spinning solution was extruded as fibers from a nozzle (syringe needle: 18 G) by applying a voltage of about 28 kV, and the fibers were deposited on a collector while the nozzle was moved a width of 100 mm to 150 mm at a speed of 40 mm/sec and the needle tip was cleaned at an interval of 2 minutes (condition in chamber=temperature: 30 centigrade temperature or less; humidity: 50% or less; length from needle tip to device floor: 37 cm). The deposited fibers were dried at room temperature to obtain a carboplatin-containing cotton-like material.
[0000]
TABLE 5
Concentration
Formation of
Amount of
Amount of
of
cotton-like
Sample name
polymer
carboplatin
carboplatin
shape
1-fold amount
3.0 g
15 mg
0.50%
Success
10-fold amount
3.0 g
150 mg
4.8%
Success
30-fold amount
3.0 g
450 mg
13%
Success
60-fold amount
3.0 g
900 mg
23%
Failure
[0149] Results
[0150] FIG. 5 is a SEM photograph of the obtained carboplatin-containing polylactic acid-glycolic acid copolymer (30-fold amount). The fibers are three-dimensionally intertwined to form a cotton-like material. The fibers are not adhered to each other in the longitudinal direction and form a fluffy three-dimensional cotton-like structure. The fibers had an average outer diameter of 50 μm to 110 μm, and partially had an outer diameter of 1 to 10 μm.
<Example 2> Measurement of Elastic Force
[0151] The elastic forces of the 30-fold amount of carboplatin-containing polylactic acid-glycolic acid copolymer (hereinafter, referred to as a sample for DDS) prepared in Example 1 and ReBOSSIS (registered trademark) (40TCP-30SiV-30PLLA prepared in Reference Example 1) were measured and compared with the those of ReFit (HOYA Technosurgical Co., Ltd.) and OSferion (Olympus Terumo Biomaterials Corp.) that are approved artificial bone products.
[0152] Materials
[0153] The outline of each of the samples used is shown in Table 6.
[0000]
TABLE 6
Outline of Samples of Elastic Force Test
Porosity
Hydration
Sample name
Components
Shape
Size
[%]
amount
ReBOSSIS
Polylactic acid,
Fibrous
0.1 g (2.5 ml)
About 98%
0.8 cc
β-tricalcium
phosphate, silicon-
containing vaterite
Sample for DDS
Polylactic acid-
Fibrous
0.1 g
N/A
1.6 cc
glycolic acid
copolymer
carboplatin
ReFit
Low-crystalline
Block
10 × 10 × 10 mm
95%
1 cc
calcium phosphate +
(1.0 ml)
collagen
OSferion
β-tricalcium
Block
10 × 10 × 10 mm
73~82
1 cc
phosphate
(1.0 ml)
[0154] Method
[0155] First, 0.1 g of ReBOSSIS or the sample for DDS or 10×10×10 mm (1.0 mL) of ReFit or OSferion was placed in a transparent tube having an inner diameter of 22 mm. In an experiment under hydration conditions, 0.8 cc, 1.6 cc, and 1 cc of pure water was added to ReBOSSIS, the sample for DDS, and ReFit and OSferion, respectively. A designated lid (0.417 g) was placed on each of the samples. The bulk height at this time was defined as h 0 .
[0156] Then, a designated weight (9.911 g) was placed on the lid, and the bulk height at this time was defined as h 1 .
[0157] Finally, the weight was removed, and the bulk height at this time was defined as h 2 . The h 0 , h 1 , or h 2 was determined by calculating the average of heights measured at the four corners of the lid.
[0158] FIG. 6 shows the calculation method of a compression rate and the calculation method of a recovery rate.
[0159] Results
[0160] The results of the elastic force test are shown in Table 7 on the next page. The compression rates and recovery rates determined by calculation are shown in Table 8. Further, the photographs of the experiment (left: before adding weight, center: during adding weight, right: after removal of weight) are also shown in FIG. 7 .
[0000]
TABLE 7
Results of Elastic Force Test
Dry [mm]
Hydration [mm]
ReBOSSIS
h 0
10.3
h 0
9.2
h 1
6.1
h 1
5.5
h 2
7.3
h 2
5.6
Sample for DDS
h 0
14.9
h 0
9.9
h 1
9.1
h 1
8.1
h 2
11.6
h 2
8.5
ReFit
h 0
12.0
h 0
12.0
h 1
12.0
h 1
12.0
h 2
12.0
h 2
12.0
OSferion
h 0
12.0
h 0
13.0
h 1
12.0
h 1
13.0
h 2
12.0
h 2
13.0
[0000]
TABLE 8
Results of Determination of Compression Rate and Recovery Rate
Experimental
Compression
Recovery
item
Description of experiment
State
Sample
rate(%)
rate (%)
Elastic
Measurement of recovery
Dried
ReBOSSIS
41
27
force
volume after compression
state
Sample for DDS
39
44
ReFit
0
0
OSferion
0
0
Hydrated
ReBOSSIS
39
3
state
Sample for DDS
14
24
ReFit
0
0
OSferion
0
0
[0161] The compression rate and recovery rate of ReFit or OSferion were both 0, whereas ReBOSSIS or the sample for DDS had certain compression rate and recovery rate.
[0162] It is to be noted that when the bulk density of the sample for DDS obtained in Example was measured with reference to JIS L1097, the bulk density in a dried state was 0.0177 g/cm 3 , and the bulk density in a hydrated state was 0.0266 g/cm 3 .
[0163] The results suggest that the bioabsorbable cotton-like material according to the present invention can be compressed when inserted into an injector or the like, introduced into the body through the injector by a minimally invasive medical procedure, and then quickly recover its volume in the body.
<Example 3> Shape Processability and Size Processability
[0164] In terms of shape processability and size processability, the 30-fold amount of carboplatin-containing polylactic acid-glycolic acid copolymer (hereinafter, referred to as a sample for DDS) prepared in Example 1 and ReBOSSIS (registered trademark) (40TCP-30SiV-30PLLA prepared in Reference Example 1) were compared with ReFit (HOYA Technosurgical) and OSferion (Olympus Terumo Biomaterials Corp.) that are approved artificial bone products.
[0165] The outline of each of the samples used is shown in Table 9, and the shape of each of the samples is shown in FIG. 8 .
[0000]
TABLE 9
Outline of Samples
Hydration
Sample name
Components
Shape
Size
Porosity [%]
amount
ReBOSSIS
Polylactic acid,
Cotton-like
About 98%
β-tricalcium phosphate
shape
silicon-containing vaterite
ReFit
Low-crystalline
Block
10 × 10 × 10 mm
95%
1 cc
calcium phosphate +
(1.0 ml)
collagen
OSferion
β-tricalcium
Block
10 × 10 × 10 mm
73~82
1 cc
phosphate
(1.0 ml)
Sample for DDS
PLGA, carboplatin
Block
1.0 g
NA
indicates data missing or illegible when filed
[0166] 1. Shape Processability
[0167] Whether or not each of the samples could be processed using tools into a shape that could be contained in a cylindrical plastic container having a diameter of 8.5 to 9 mm was determined. The tools used were tweezers, a cutter, and osteotomy scissors. Whether or not each of the samples could be processed using these tools was determined, and the time required to process each of the samples into a cylindrical shape was determined. The shape processability of each of the samples was determined in a dried state and a hydrated state. Please see the above for the samples used and hydration amounts.
[0168] 2. Size Processability
[0169] Whether or not each of the samples could be torn in half by hands and could be again put the halves together after tear was determined. The shape processability of each of the samples was determined in a dried state and a hydrated state. Please see the above for the samples used and hydration amounts.
[0170] Results
[0171] 1. Shape Processability
[0000]
TABLE 10
Results of Examination for Shape Processability
Results
Necessary
Tweezers
Ostectomy
time
State
Sample
(manual)
Cutter
scissors
(s)
Shape
Dried
ReBOSSIS
◯
◯
◯
11
processability
state
ReFit
X
◯
◯
181
OSferion
X
◯
◯
534
Sample for DDS
◯
◯
◯
10
Hydrated
ReBOSSIS
◯
◯
◯
10
state
ReFit
Δ
◯
◯
96
OSferion
X
◯
◯
297
Sample for DDS
◯
◯
◯
14
[0172] FIG. 9 shows the samples after processing and the samples contained in plastic containers.
[0173] ReBOSSIS in a dried state and ReBOSSIS in a hydrated state could be both manually shaped, and could be packed in a plastic container in a short time because their shapes could be easily processed. ReFit in a dried state needed to be processed with a cutter, and therefore it took time for shaping. ReFit in a hydrated state could be relatively quickly shaped because its shape could be changed by hands to some extent. The properties of OSferion were hardly changed even in a hydrated state, and therefore it took time for shaping both in a dried state and a hydrated state.
[0174] As in the case of ReBOSSIS, the shape of the sample for DDS could be processed in a short time.
[0175] 2. Size Processability
[0000]
TABLE 11
Results of Examination for Size Processability
Item
State
Sample
Result
Size
Whether or not
Dried state
ReBOSSIS
◯
processability
the sample can
ReFit
X
be torn
OSferion
X
into pieces
Sample for DDS
◯
Hydrated
ReBOSSIS
◯
state
ReFit
Δ
OSferion
X
Sample for DDS
◯
Whether or not
Dried state
ReBOSSIS
◯
the pieces can
ReFit
X
be put together
OSferion
X
after tear
Sample for DDS
◯
Hydrated
ReBOSSIS
◯
state
ReFit
X
OSferion
X
Sample for DDS
◯
[0176] ReBOSSIS in a dried state and ReBOSSIS in a hydrated state both could be torn into pieces by hands, and then the pieces could be again put together. ReFit could be torn into pieces by hands after hydration, but could not be torn in an arbitrary shape. Therefore, the degree of freedom of size processing was lower than that of ReBOSSIS. As in the case of ReBOSSIS, the sample for DDS could be torn into pieces by hands, and then the pieces could be again put together.
[0177] This result suggests that the bioabsorbable cotton-like material according to the present invention can be very easily shaped so as to fit in the site of implantation.
<Example 4> Sustained Releasability of Bioabsorbable Cotton-Like Material Carrying Anticancer Agent
Method
[0178] First, 25 mg of a 30-fold amount of carboplatin-carrying cotton-like material was weighed and placed in each 1.5 cm 3 Eppendorf tube. Then, 0.5 cm 3 of pure water was added thereto to immerse the cotton-like material in the pure water. At specified time intervals, the cotton-like material was removed with tweezers and transferred into an empty 1.5 cm 3 Eppendorf tube. Then, 0.5 cm 3 of pure water was newly added to the empty Eppendorf tube to exchange the solution. (The solution was exchanged once in the morning after a lapse of 1 day or more).
[0179] The amount of carboplatin at each sampling time was measured with an ultraviolet spectrophotometer. Specifically, 10 μL of the stored solution obtained at each sampling time was weighed and diluted with ultrapure water in a 100 μL cell (10-fold dilution) to measure the amount of carboplatin. In this experiment, the number of samples to be measured was 3 (n=3). Conditions for measurement of sustained releasability and UV measurement are as follows.
[0180] Measurement Conditions
[0181] Sampling time: 5 min, 1, 2, 4, 6 h, 1, 2, 3, 4, 7 day
[0182] Detection condition: UV (220 nm)
[0183] Results
[0184] The sustained-release behavior of carboplatin from the cotton-like carrier was observed over 168 hours ( FIG. 10 ).
[0185] Therefore, it can be said that the cotton-like carrier is a very excellent drug carrier capable of locally administering an anticancer agent for a long term.
<Example 5> Effectiveness of Bioabsorbable Cotton-Like Material Carrying Anticancer Agent as Novel Drug Delivery (DDS) Material
[0186] Method
[0187] A homozygous (Tg/Tg) mouse strain was used which was established by backcross of transgenic (Tg) mice that express a MYCN gene from the promoter of Tyrosine Hydroxylase (TH) that is a sympathetic nerve-specific enzyme (NON-PATENT LITERATURE 5: Weiss et al) with 129tTer/SvJcl wild-type mice (CLEA Japan) (NON-PATENT LITERATURE 6: Kishida et al). These mice, in which neural crest cells are fated to differentiate into sympathetic neurons and MYCN is expressed at the timing of expressing TH that is one of markers, spontaneously develop neuroblastoma from the superior mesenteric ganglion that is one of sympathetic ganglia and die at about 7 to 8 to 9 weeks of age. Heterozygous mice develop tumors and die 2 months after birth or later (at 9 to 20 weeks of age) when they reach sexual maturity.
[0188] An experiment was performed in which the 30-fold amount of carboplatin-containing polylactic acid-glycolic acid copolymer (bioabsorbable cotton-like material (cotton-like carrier)) prepared in Example 1 was implanted in the abdominal cavity of a homozygous (Tg/Tg) mouse (in the vicinity of the abdominal superior mesenteric ganglion that is a main site where neuroblastoma occurs (between both the kidneys)) according to the following experimental protocol (Table 12), carboplatin was directly administered into the abdominal cavity of a mouse in the same amount as contained in the cotton-like carrier, and phosphate buffered saline (PBS) was administered into the abdominal cavity of a mouse as a control for comparison.
[0000]
TABLE 12
Group name
Male 30_1*
Female 30_1
Female 30_2
Mouse No
M169
F166
F179
Carrier
30-fold amount
30-fold amount
30-fold amount
carrier
carrier
carrier
Amount of
0.05 g
0.05 g
0.025 g
carrier
implanted
Birth day
150607
150519
150716
Start date of
150703
150617
150822
implantation
End date of
150831
150727
151016
implantation
Amount of
58
51 (Euthanasia)
56 (Euthanasia)
days of
living after
implantation
[0189] Results
[0190] The mice that were not implanted with the cotton-like carrier died at 7 to 8 weeks of age, but the mice implanted with the cotton-like carrier continued to live beyond the age of 8 weeks, and F166 and F179 were euthanized at 12 weeks of age.
[0191] FIG. 11 shows the mouse during dissection which developed cancer and died at 8 weeks of age, and FIG. 12 shows the mouse (F166) during dissection which was implanted with the cotton-like carrier and euthanized at 12 weeks of age.
[0192] The changes in the body weights of the mice after implantation surgery are shown in FIG. 13 .
[0193] In the mouse shown in FIG. 11 , a very large tumor enough to fill the gap between the left and right kidneys was observed, and the mouse obviously died from cancer. On the other hand, in the mouse shown in FIG. 12 , a tumor was not observed at all even after a lapse of 12 weeks. Therefore, the abdominal ganglion (F 166) was excised and fixed with formalin ( FIG. 14 ).
[0194] As shown in FIG. 12 , the cotton-like carrier remained. This is because only 8 weeks (12 week-old) had passed after implantation. It is expected that the cotton-like carrier is entirely absorbed by the body in about a half year after implantation.
[0195] As can be seen from FIG. 13 , the body weights of the mice implanted with the cotton-like carrier increased similarly to sham-surgery mice. This reveals that the side effects of the anticancer agent did not occur. Even after the sham-surgery mice died from cancer at 8 weeks of age, the body weights of the mice implanted with the cotton-like carrier continued to steadily increase. This suggests that the mice were cured of cancer.
[0196] FIGS. 15 and 16 show the H&E-stained sections of the mouse implanted with the cotton-like carrier ( FIG. 14 ).
[0197] From FIGS. 15 and 16 , the following findings were obtained.
“Neuroblastoma cells” that had small cell bodies and were poor in cytoplasm were not observed. Calcification and scarring with fibroblasts were observed.
[0200] From the above, it is estimated that cancer cells were killed by the anticancer effect of the cotton-like material, and the killed cancer cells remained as scarring.
[0201] FIG. 17 shows the appearance of the mouse to which carboplatin was directly intraperitoneally administered in the same amount as contained in the cotton-like carrier and the mouse during dissection, and FIG. 18 shows the appearance of the mouse to which PBS was directly administered as a control for comparison and the mouse during dissection.
[0202] It is to be noted that the mice to which carboplatin was directly intraperitoneally administered were healthy mice, but all the mice died within several days. On the other hand, the mice to which PBS was administered lived three weeks or more after administration, and were therefore euthanized in the fourth week after administration.
[0203] As can be seen from FIG. 17 and FIG. 18 , when carboplatin was directly administered in the same amount as contained in the cotton-like carrier, the mice died due to the occurrence of serious side effects.
[0204] The LD50 (50% lethal dose) of carboplatin intraperitoneally administered to mice is 150 mg/kg. Therefore, in the case of a mouse having a body weight of 30 g, the LD50 is 4.5 mg. The amount of carboplatin contained in 0.05 g of the 30-fold amount of carboplatin-containing carrier was 7.5 mg, which means that carboplatin was implanted in a larger amount than LD50. However, the mice M169, F166, and F179 lived and were successfully treated for cancer. It is indicated that even when the amount of carboplatin exceeded LD50, the use of the carrier allowed sustained release of carboplatin and therefore reduced side effects.
SUMMARY
[0205] In the experiment using neuroblastoma model mice, mice to which carboplatin was directly administered died from serious side effects in several days before the end of life. On the other hand, mice implanted with the cotton-like carrier lived beyond a life-span of 8 weeks without side effects and were euthanized at 12 weeks of age for autopsy. As a result of pathological examination, no cancer cells were observed.
[0206] Therefore, the cotton-like carrier made it possible to locally administer an anticancer agent without causing systemic side effects and to kill cancer cells.
[0207] From the above, the anticancer agent-carrying bioabsorbable cotton-like material is very effective as a novel drug delivery (DDS) material.
INDUSTRIAL APPLICABILITY
[0208] As described above, the biodegradable fibers according to the present invention can provide a drug formulation material that is capable of locally and sustainably releasing a drug at any site in the body for a long period of time, that has bioabsorbability, and that is absorbed and broken down by the body after sustained release of the drug.
[0209] Further, implantation of the drug formulation in a patient can produce a therapeutic/preventive effect to enhance QOL (Quality of Life) without causing systemic side effects.
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The present invention addresses the problem of providing a drug formulation material with which localized sustained release of a drug at any site in the body is possible, and which has good bioabsorption and is absorbed and broken down by the body after sustained release of the drug. A drug formulation material that has an exceedingly high sustained release effect, and that solves the foregoing problem, was successfully developed by dissolving a biodegradable resin and a drug in a solvent to prepare a spinning solution, and spinning fibers from the spinning solution by electrospinning.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of and claims priority from U.S. application Ser. No. 13/396820 filed on Feb. 15, 2012, which in turn claims priority under 35 U.S.C. 119 from Japanese Application 2011-040262, filed Feb. 25, 2011, the entire contents of both applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a technique for acquiring checkpoints in making iteration-method computer calculations in parallel to effectively utilize the acquired data for recovery.
[0004] 2. Description of Related Art
[0005] As the scale of supercomputers increases, the increase in time required for checkpoints is becoming problematic. The acquisition of a checkpoint takes a lot of time. Since a checkpoint of memory is acquired at a particular point of time while rewriting continues, overhead for securing consistency, such as suspension of calculation during the acquisition of the checkpoint, is required.
[0006] A first example of a technique currently used is copy-on-write and incremental checkpointing. After write-protecting memory by using copy-on-write in this scheme, a checkpoint is acquired in advance without stopping (interrupting) calculation. The calculation is stopped after acquiring the checkpoint in advance, and an updated part copied by the copy-on-write mechanism during acquisition of the checkpoint is reflected on the checkpoint acquired in advance.
[0007] A disadvantage of this scheme is that this approach can be said to be effective only when a small extent of the memory is updated. In the case of applying this approach to LU decomposition calculation, a method of solving Poisson's equation and the like, a large extent of memory is updated during acquisition of a checkpoint. Therefore, stop time for reflecting changes on the checkpoint acquired in advance is required, and the stop time cannot be saved.
[0000] A second example of a technique currently used is the use of a nonvolatile medium other than a disk, such as a flash memory, an MRAM or the like. In this scheme, time is reduced by temporarily copying data to a high-speed nonvolatile medium before writing the data to a low-speed medium such as an HDD.
[0008] A disadvantage of this scheme is the high additional cost for the nonvolatile memory.
[0009] In addition, as for element techniques related to the acquisition of a checkpoint, there are techniques as disclosed in Japanese Patent Laid-Open No. 7-271624 and Japanese Patent Laid-Open No. 9-204318. However, none of these relate to iteration-method calculation.
[0010] The object of the present invention is to acquire checkpoints in making iteration-method computer calculations in parallel and to effectively utilize the acquired data for recovery.
SUMMARY OF THE INVENTION
[0011] In order to overcome these deficiencies, the present invention provides a method implemented in a system including a certain node and at least one other node, the method including: starting, by the certain node, computer calculations based on a data group for calculation belonging to a certain discrete time and executing an iteration-method calculation until a result of the calculations are converged within a predetermined range; acquiring, by the certain node, an intermediate calculation group as a checkpoint at a predetermined timing, in parallel with the execution of the iteration-method calculation, without stopping the started computer calculations; storing, by the certain node, the acquired intermediate calculation group as a checkpoint into an external memory; waiting, by the certain node, until it is confirmed that all the above-stated processes are performed in parallel in the other node and have been completed before evolving the certain discrete time to a next discrete time; and referring, by the certain node, in response to the completion being confirmed, to a converged calculation result and starting next computer calculations based on a next data group for calculations belonging to the next discrete time.
[0012] According to another aspect, the present invention provides a system including a certain node and at least one other node, wherein: the certain node starts computer calculations based on a data group for calculation belonging to a certain discrete time and executes an iteration-method calculation until a result of the calculation is converged within a predetermined range; the certain node acquires an intermediate calculation group as a checkpoint at a predetermined timing, in parallel with the execution of the iteration-method calculation, without stopping the started computer calculations; the certain node stores the acquired intermediate calculation group as a checkpoint into an external memory; the certain node waits until it is confirmed that all the above-stated processes are performed in parallel in the other node and have been completed before evolving the certain discrete time to a next discrete time; and in response to the completion being confirmed, the certain node refers to a converged calculation result and starts next computer calculations based on a next data group for calculation belonging to the next discrete time.
[0013] According to yet another aspect, the present invention provides A node capable of independently making computer calculations, including a CPU, a check system and a memory, the node being linked with at least one other node so as to be communicable with each other, the computer calculations being made in parallel between these multiple nodes while a data group for calculation belonging to some discrete time is evolved from a certain discrete time to a next discrete time, wherein the node: starts computer calculations based on the data group for calculation belonging to the certain discrete time and executes an iteration-method calculation until a result of the calculation is converged within a predetermined range; acquires an intermediate calculation group as a checkpoint at a predetermined timing in parallel with the execution of the iteration-method calculation without stopping the started computer calculation; stores the acquired intermediate calculation group as a checkpoint into an external memory; waits until it is confirmed that all the above-stated processes are performed in parallel in the other node and have been completed before evolving the certain discrete time to the next discrete time; and in response to the completion being confirmed, refers to a converged calculation result and starts next computer calculations based on a next data group for calculation belonging to the next discrete time.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] FIG. 1 is a diagram showing the configuration of a node to be a basic unit and the configuration of multiple such nodes forming a communication link to which the present invention is applied;
[0015] FIG. 2 is a schematic diagram illustrating time evolution in iteration-method calculation and acquisition of a checkpoint;
[0016] FIG. 3 is a diagram comparing a conventional approach and an approach of the present invention;
[0017] FIG. 4 is a diagram showing a procedure for acquiring a checkpoint;
[0018] FIG. 5 is a diagram showing a procedure for recovery from a checkpoint;
[0019] FIG. 6 is a graph of cost for reliability which is expected when the approach of the present invention is implemented and which has been theoretically calculated; and
[0020] FIG. 7 is a graph showing an example of applying the approach of the present invention to a Poisson's equation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 1 is a diagram showing configuration of a node to be a basic unit and configuration of multiple such nodes forming a communication link to which the present invention is applied. Though any external memory connection scheme and any kind of memory are possible in various embodiments of the present invention, a nonvolatile memory connected via NAS/SAN or the like, such as a hard disk, is commonly used as an external memory.
[0022] Each node includes a CPU (calculation body), a checkpoint system and a memory and can independently make computer calculations. In FIG. 1 , there is shown a node (self-node) and at least one other node (non-self-node) among all nodes which make calculations in parallel, and these multiple nodes are linked so that they can communicate with one another.
[0023] FIG. 2 is a schematic diagram illustrating time evolution in an iteration-method calculation and acquisition of a checkpoint. It is a basis of computer calculation (physical phenomenon simulation or the like) to make the computer calculations in parallel while time-evolving a data group for calculation (such as a data array) belonging to some discrete time from a certain discrete time (t=k−1) to the next discrete time (t=k).
[0024] Regarding the data group for calculation, for example, a differential equation expressed by a Poisson's equation is discretized in a form like meshes in a two-dimensional space expressed by x or y as shown in the figure, and a physical variable is given at each of the mesh intersections (x 1 , y 1 ), (x 2 , y 1 ), (x 3 , y 1 ), . . . . In a computer calculation, the amount of memory occupied is reduced by overwriting a new value calculated as the value of a mesh intersection in the process of time evolution. In common programming, an array in a computer program is used as a framework for storing values corresponding to the number of mesh intersections×the number of kinds of physical variables until the next discrete time.
[0025] At the certain discrete time (t=k−1), (convergence) calculation is started. The calculation is not advanced to the next discrete time (t=k) until the calculation result is converged within a predetermined range. The name “iteration method” is derived from the fact that the calculation is iteratively repeated until the calculation result is converged. As for the “predetermined range” for use in determining whether the calculation result has been converged or not, one skilled in the art could introduce various kinds of threshold decisions or appropriately change the range according to the condition of convergence. It is known that the condition of convergence also influences the degree of discretization of time t [here, the interval between (k−1) and k].
[0026] In the present embodiment, an intermediate calculation data group as a check point is acquired at a predetermined timing (point of time) in the course of execution of the iteration-method calculation. This acquisition is performed by an asynchronous I/O (input/output) operation without stopping/suspending the started computer calculation.
[0027] FIG. 3 is a diagram comparing a conventional approach and an approach of the present embodiment. In conventional approaches, a synchronous I/O operation of acquiring a checkpoint at a calculation start point of time has been performed. In the approach of the present invention, a checkpoint in the course of calculation is acquired by an asynchronous I/O operation without stopping/suspending the computer calculation. According to the approach of the present embodiment, it is possible to continue executing the iteration-method calculation, but a mixture of time at different predetermined points of time may be included.
[0028] Therefore, it is important for the self-node to store the acquired intermediate calculation data group as a check point in the external memory. This is because the computer calculation is started there in the case of recovery from the checkpoint.
[0029] FIG. 4 is a diagram showing a procedure for acquiring a checkpoint. FIG. 4 shows a procedure as an aspect in which the CPU (calculation body) and the checkpoint system shown in FIG. 1 are separated and are in cooperation with each other. However, one skilled in the art could practice the present invention in various other variations, for example, in an embodiment as hardware resources, an embodiment as software resources (such as a computer program) and an embodiment in which hardware resources and software resources are in cooperation with each other.
[0030] The calculation body starts convergence calculation at 10 . At 20 , a checkpoint acquisition instruction is transmitted to the checkpoint system of the self-node (coordination with the checkpoint system). At 30 , the convergence calculation is resumed and executed to the end thereof. At 40 , an end notification is received from the checkpoint system (coordination with the checkpoint system). At 50 , the procedure returns to 10 for convergence calculation for the next discrete time.
[0031] At 60 , the checkpoint system receives a checkpoint acquisition start instruction from the calculation body. At 70 , the contents of the memory are stored in the external memory. At 80 , the checkpoint system waits until it is confirmed that all the above-stated steps performed in parallel in all the relevant nodes have been completed, by barrier synchronization between the at least one other node (non-self-node) and the checkpoint system before time-evolving discrete time to the next discrete time.
[0032] At 90 , the checkpoint system transmits a checkpoint acquisition end notification to the calculation body of the self-node in response to the completion being confirmed, and the notification is received by the calculation body at 40 (coordination with the calculation body). Thereby, at 50 , the calculation body of the self-node refers to the converged calculation result and starts a computer calculation based on a data group for calculation belonging to the next discrete time. At 100 , the procedure returns to 60 for convergence calculation for the next discrete time. Before time evolution to the next discrete time, it is possible to continuously acquire (or prepare to acquire) a checkpoint at a different timing (point of time).
[0033] FIG. 5 is a diagram showing a procedure for recovery from a checkpoint. Similar to that of FIG. 4 , FIG. 5 shows a procedure as an embodiment in which the CPU (calculation body) and the checkpoint system shown in FIG. 1 are separated and are in cooperation with each other.
[0034] At 110 , the calculation body transmits a checkpoint recovery start instruction to the checkpoint system of the self-node (coordination with the checkpoint system). At 120 , a checkpoint recovery end instruction is received from the checkpoint system (coordination with the checkpoint system). At 130 , execution of the convergence calculation being executed at the time of acquiring the checkpoint is resumed from the start thereof.
[0035] At 140 , the checkpoint system receives a checkpoint recovery start instruction from the calculation body of the self-node (coordination with the calculation body). At 150 , the contents of the memory are recovered from the external memory. At 160 , the checkpoint system waits until it is confirmed that all the above-stated steps performed in parallel in all the relevant nodes have been completed, by barrier synchronization between the at least one other node (non-self-node) and the checkpoint system. At 170 , a checkpoint recovery end notification is transmitted to the calculation body of the self-node, and the notification is received by the calculation body at 120 . Thereby, at 130 , the calculation body of the self-node resumes execution from the start of the convergence calculation being executed at the time of acquiring the checkpoint.
[0036] In the present embodiment, since calculation is not stopped at the time of acquiring a checkpoint, the data in which the contents of the memory acquired at different timings (points of time) are mixed are used for a process of recovery from the checkpoint. The reason why use of such data is permitted is that its use is limited to iteration-method convergence calculation. In general, in an iteration method, an approximate value calculated in another method, a fixed value (for example, all zeros), a random number or the like is used as an initial value of a solution. In the calculation, approximation is performed on the basis of a given initial value so that difference from a correct solution (residual) becomes smaller every iteration, and the iteration is repeated until the residual is equal to or smaller than a value specified in advance.
[0037] In the present approach, among checkpoint data, the data in which values at different points of time are mixed is acquired. However, in the present embodiment, since the problem that a convergence destination does not depend on an initial value is assumed, convergence to the same value is guaranteed regardless of an initial value. That is, among checkpoint data, even if the data in which values at different points of time are mixed is used, the termination of calculation in the case of being recovered and the validity of a calculation result are guaranteed.
[0038] Next, the number of iterations for convergence in the case of being recovered from the data in which values at different points of time are mixed, among checkpoint data, will be described. In an iteration method, the current solution is made closer to a correct solution every iteration. Therefore, in general, by using an initial value closer to the correct solution, convergence to the correct solution becomes possible by a smaller number of iterations. Thus, an initial value closer to a correct solution can be obtained by using a value after more iterations have been performed even if acquisition points of time are mixed, like the checkpoint acquisition method of the present invention, and thereby, the number of iterations performed until convergence at the time of recovery can be reduced.
[0039] The approach of the present embodiment can be embodied as a node, a method implemented in the node, or a method or system for making computer calculations in parallel among multiple nodes. The present approach can be also embodied as a computer program product including a computer readable storage medium having computer readable non-transient program code embodied therein, causing a CPU (calculation body), a check system or an integration thereof which is included in a certain node (self-node), to execute each step of the method.
[0040] FIG. 6 is a graph of the cost for reliability expected when the approach of the present embodiment is implemented and which has been theoretically calculated. Theoretical values are shown which are calculated as calculation time loss cost on the assumption that overhead=checkpoint acquisition cost+failure, in the case of MTBF of 0.3 days and the amount of time required for checkpoint of 10 minutes.
[0041] However, the calculation is performed on the condition that the calculation time is not increased by the background checkpoint acquisition overhead. (It is assumed that resources other than a CPU performing calculations are not used at all or almost at all. In the case of using I/O resources, the effect of the invention may be reduced according to the rate of the use.)
[0042] The “proposed (estimation)” data in the graph indicates theoretical overhead values when the present invention is applied. Other data indicate overhead when the checkpoint acquisition interval is set as 1 hour, 2 hours, 6 hours and 1 day, respectively. The present embodiment was successful in reducing overhead of 11.1% in the case of the checkpoint interval of 1 day and the MTBF of 10 days to about 0.4%.
[0043] FIG. 7 is a graph showing an example of applying the approach of the present invention to a Poisson's equation.
[0044] Calculation conditions are enumerated below:
[0000] Equation: Poisson's equation
Calculation algorithm: Gauss-Seidel
The number of input data (=two-dimensional data arrays): 16384 (=128×128)
Checkpoint acquisition speed: 32 points/iteration (=checkpoint acquisition interval of 512 iterations)
The number of iterations which have been performed when checkpoint acquisition ends: 500, 1000, 1500
[0045] In the present embodiment example the same scheme as shown in the above configuration and procedures is used. However, the checkpoint system and the calculation body in the above configuration are integrated and realized as the same program. There are shown below residuals in the case of acquiring checkpoints at the 500th, 1000th and 1500th iterations after the start of calculation and recovering from the acquired checkpoints. In order to show how the number of iterations before acquisition influences the number of iterations after acquisition, the graph shows the residuals after recovery on the basis of the number of iterations before checkpoint acquisition.
[0046] Furthermore, embodiment examples to which the present invention can be applied include (1) to (4) below:
[0000] (1) Applicable to calculation based on convergence calculation by an iteration method in which a convergence value is decided irrespective of an initial solution. A BiCG method is an example;
(2) Applicable to calculation using the Poisson equation, because it is guaranteed that in the Poisson equation a convergence value is decided regardless of an initial value. The Poisson equation is used in a variety of fields such as CFD, electrostatics, mechanical engineering, theoretical physics and first principles calculation;
(3) Applicable to calculation in which a convergence value differs depending on an initial solution. However, it is also conceivable that, by applying the present invention, convergence to a value other than an original convergence value occurs or convergence does not occur after recovery from a checkpoint. In the problem of including such calculation that a convergence value differs depending on an initial solution, there is a possibility that an execution result may change due to application of the present invention. If a user accepts this condition, the present invention can be applied to the calculation in which a convergence value differs depending on an initial solution; and
(4) At the time of acquiring a checkpoint, asynchronous communication using RDMA (Remote Direct Memory Access) or the like can be used instead of the asynchronous I/O. In this case, the checkpoint system operates on a node other than the self-node, but the procedure itself is the same. By using RDMA, checkpoint acquisition can be performed without using CPU resources of a target node. Thereby, an increase in convergence calculation time ( 30 in FIG. 4 ) caused by the checkpoint acquisition can be reduced, and the advantages of the present invention can be enhanced.
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A method and system to acquire checkpoints in making iteration-method computer calculations in parallel and to effectively utilize the acquired data for recovery. At the time of acquiring a checkpoint in parallel calculation that repeats an iteration method, each node independently acquires the checkpoint in parallel with the calculation without stopping the calculation. Thereby, it is possible to perform both of the calculation and the checkpoint acquisition in parallel. In the case where the calculation does not impose an I/O bottleneck, checkpoint acquisition time is overlapped, and execution time is reduced. In this method, checkpoint data including values at different points of time during the acquisition process is acquired. By limiting the use purpose to iteration-method convergence calculations, mixture of the values at the different points of time in the checkpoint data is accepted in the problem that a convergence destination does not depend on an initial value.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to devices used to ventilate, cool, or warm persons, and more particularly to a blanket-type device which may be used to warm a body during surgical procedures.
2. Description of the Prior Art
Dozens of devices have been created to maintain a comfortable living environment for men and women. Air conditioning and heating systems for homes often meet this demand, but because of the expensive nature of such systems, and due to the fact that different individuals frequently have different desires concerning ambient conditions, several inventions have been devised to warm or cool smaller areas or spaces. A good example is an electrical heating pad, which may vary in size from about one square foot to the size of a bed, making it a heating blanket.
There have been several improvements on the idea of a heating/cooling blanket. One device, disclosed in U.S. Pat. No. 3,602,001 issued to Bauer et al., actually contemplates burning a fuel mixture within a garment. This patent is somewhat removed from more conventional devices, such as the one shown in U.S. Pat. No. 2,504,308 issued to L. Donkle. The Donkle device comprises a blanket having conduits therein which may act either as condensing coils or evaporation coils, depending on the orientation of a valve system with an external compressor. A similar product is depicted in U.S. Pat. No. 2,617,915 issued to G. Blair. Air is passed through a series of "tortuous" channels to provide even inflation. A unique variation of this idea is further shown in U.S. Pat. No. 2,991,627 issued to C. Suits, which discloses the use of Peltier junctions for cooling the person using the blanket. Another invention, described in U.S. Pat. No. 3,867.939 issued to Moore et al., is directed to a layered heating/cooling blanket having an absorbent stratum which may act as an absorbent bandage or be used to apply medicaments. Each of these blankets may be used in a hospital setting in which maintenance of proper body temperature may be critical.
The above-mentioned devices suffer one important drawback--the warm or cool air flowing through the blanket does not come into direct contact with the body, but rather heat transfer must be completed through the blanket material, dissipating the desired effect. This is especially detrimental in the case of small children whose total heat capacity is very low. Some other inventions, however, have overcome this problem by providing a series of air holes in the blanket itself by which the warm or cool air may be directed at the patient. One such invention is shown in U.S. Pat. No. 3,486,177 issued to I. Marshack. In that invention, a permeable cushion is placed over conduits having holes therein; the air flows upwards through the cushion and to the body of the person lying thereon. Obviously, however, the same problem of heat dissipation occurs in the cushion itself. Another version is depicted in U.S. Pat. No. 2,601,189 issued to N. Wales. That blanket utilizes a series of channels which provide uniform distribution of the air; however, the Wales blanket is designed to be placed over the subject, not underneath him, making it useless for surgical procedures since the surgeon must have access to the patient's body. If the Wales blanket is placed underneath the subject, the weight of the body will cut off distribution to the distal ends of the channels. A better design is disclosed in U.S. Pat. No. 2,512,559 issued to A. Williams, in which the two layers of material forming the blanket are spot welded or stitched, whereby the conditioned air may circulate around those portions of the blanket which are compressed due to the weight of the patient's body. Nevertheless, as a practical matter, it has been found that devices such as Williams are not suitable for their intended use because of the tremendous heat loss that occurs in the supplied air between the inlet hose and the distal end of the blanket. In other words, although the air exiting the holes near the inlet port is warm enough to provide heating capability, the temperature of the air exiting the holes which are farther away from the inlet port is close to ambient temperature, which typically has the undesirable effect of actually cooling the patient. If the temperature of the supplied air is raised in order to raise the temperature of the air exiting the distal holes, then the air exiting the proximate holes is so hot as to cause discomfort, and even first degree burns. It would, therefore, be desirable and advantageous to devise a blanket which could warm the body of a patient from underneath, which would overcome the above-identified drawbacks.
SUMMARY OF THE INVENTION
Accordingly, the primary object of the present invention is to provide a blanket which may warm an individual.
Another object of the invention is to provide such a blanket which has a plurality of holes therein providing direct contact between the individual and heated air which is circulated through the blanket.
Yet another object of the invention is to provide such a blanket which may be placed underneath the individual, so that surgical procedures may be performed.
Still another object of the invention is to provide a convection blanket warmer having improved distribution of heat content.
The foregoing objects are achieved in a convection blanket warmer comprising four layers, two inner layers of metallic foil, and two outer layers of a protective, absorbent material. The holes in one side of the blanket are graduated whereby there are fewer holes near the inlet port supplying heated air, and more holes near the end distal from the inlet port. The inlet port is further oriented so that supplied air is directed toward the corner of the blanket most distal from the inlet port.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of the convection blanket warmer of the present invention.
FIG. 2 is a cross-sectional view of a portion of the blanket showing the layered arrangement thereof.
FIG. 3 is a top plan view of the convection blanket warmer showing the graduated arrangement of pinholes therein, the intermittent stitching not being shown for clarity.
FIG. 4 is a bottom plan view of the convection blanket warmer depicting the stitching pattern holding the various layers together.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the figures, and in particular with reference to FIG. 1, there is depicted a convection blanket warmer 10. Convection blanket warmer 10 has connected thereto an air supply mechanism 12 by way of hose 14, which may supply either warm or cold air, depending on the needs of the user. Air supply mechanisms are well known in the art, and are described in U.S. Pat. Nos. 2,504,308; 2,512,559; 2,601,189; and 2,617,915, which patents are hereby incorporated for all purposes.
As can more easily be seen in FIG. 2, convection blanket warmer 10 is essentially rectangular, and may vary in size from a small pad of about one foot by two feet, or may be large enough to completely circumbscribe an adult patient, i.e., about three feet by seven feet. Of course, convection blanket warmer 10 could appear in shapes other than rectangular but, as it in intended for use on men and women, it will most likely be generally oblong. Air hose 14 enters blanket warmer 10 at a corner 16, a portion of corner 16 being cutout forming an inlet port 18. The cutout in corner 16 is oriented such that the air from hose 14 may be directed to the distal corner 20 of blanket 10, which optimizes air flow within blanket 10.
Hose 14 may be connected to inlet port 18 by any convenient means, such as a drawstring 24 or elastic band which is attached to the circumferential perimeter of inlet port 18. In this manner, the distal end 22 of hose 14 may be inserted into port 18 and drawstring 24 tightened, thereby securing hose 14. The distal end 22 of hose 14 may be supplied with an annular protrusion 26 to better secure hose 14 within port 18. The particular means employed to connect hose 14 to inlet port 18 is not critical and, as those skilled in the art will appreciate, there are a variety of ways to accomplish this. However, it is an object of the present invention to provide an inexpensive convection blanket which may be disposable and, threfore, the use of special fittings attached to inlet port 18 is deemed undesirable by the inventor.
The construction of blanket 10 may best be understood with reference to FIG. 2, a cross-sectional view of blanket 10. There are essentially four layers, a first or top layer 28, a second layer 30, a third layer 32, and a fourth layer 34. Top layer 28 is preferably a cloth-like material. The main requirement for top layer 28 is that it have relatively good insulative properties. The inventor has found a cloth-like textile made from wood pulp suitable for that purpose.
The second layer 30 is affixed to top layer 28 by any suitable means, such as glue or another adhesive. One of the major points of novelty in the present invention lies in the use of a metallic-like ply for second and third layers 30 and 32. It has been found that all of the prior art devices discussed in the Background of the Invention above suffer the extreme disadvantage of losing heat as one progresses from the inlet corner to the corner of the blanket distal from the supply hose. This is simply due to heat transfer through the blanket into the surrounding atmosphere and to the user's body. The inventor has found that use of a metallic-like ply to reflect and contain the heat within blanket 10 has resulted in a remarkable improvement in this regard. Although metal foil would suffice, other insulating materials may be used, such as MYLAR (a trademark for a polyester film). Not only does this minimize the temperature gradient across blanket 10, but it also avoids excessive heating of a patient's body through direct heat transfer. Of course, one of the first or second layers 28 or 30 should be impermeable to air flow. Since, in the preferred embodiment, second layer 30 is an impermeable film of coated MYLAR, it is permissible that first layer 28 be constructed of the above-suggested (air permeable) wood pulp textile.
First and second layers 28 and 30 have a series of pinholes 36 therein (discussed more fully in conjunction with FIG. 3 below), whereby the warmed air may be directed upward through blanket 10. Third and fourth layers 32 and 34 are essentially identical to layers 30 and 28, respectively, except that the lower two layers 32 and 34 have no pinholes. Top layers 28 and 30 are intermittently secured to bottom layers 32 and 34 by means of stitching 38 (discussed more fully in conjunction with FIG. 4 below). All four layers are held together at the edges by seam 40, as more clearly seen in FIGS. 3 and 4.
With reference now to FIG. 3, a top plan view of blanket 10 is depicted, but the stitching 38 has been removed from this view to more clearly depict the novel pinhole pattern of the present invention. A series of pinholes 36 extend along the entire upper surface of blanket 10. As can be clearly seen, the density of holes 36 is greater near distal corner 20 than near proximate corner 16. This pattern, facilitates even distribution of heat along the entire length of blanket 10. As noted above, the air exiting near the distal corner of prior art devices is typically cooler, so the provision of extra ventilation holes at distal corner 20 overcomes this drawback. It should be noted that the pinhole pattern shown in FIG. 3 may be utilized independent of the metallic layering discussed above. However, these two novel features together create the optimum system for a convection blanket warmer.
In FIG. 3, the pinholes become more dense as one moves both laterally and longitudinally away from inlet port 18. In other words, there is a graduated effect going from port 18 toward lateral edge 42, as well as going from port 18 toward longitudinal edge 44. Although this graduation could occur along only one axis, it is contemplated that the pattern set forth in FIG. 3 is optimal. Moreover, it should be realized that a Cartesian system such as that shown in FIG. 3 is not the only generalized pattern; a polar system (not shown) could be used wherein the origin lies at inlet port 18, and the rings of pinholes are closer together as one moves toward distal corner 20. The point is merely to have more air flow near distal corner 20.
To insure that air flow within blanket 10 is uniform, there are no clearly defined channels therein (such as those disclosed in U.S. Pat. Nos. 2,617,915 and 3,867,939). Rather, as can be seen in FIG. 4, stitching 38 occurs intermittently along blanket 10. This is crucial since the weight of the patient's body will compress the layers of blanket 10, which effectively obstructs flow in much of blanket 10. If channeling were present, warm air would be totally unable to reach certain portions of the blanket, contrary to the desired goal of uniform air flow exiting blanket 10. Thus, in the present invention, air may circulate along convulated paths to reach all pinholes 36 which are exposed to the surrounding environment. Of course, some stitching or other affixation is necessary to avoid blowing up the blanket like a balloon.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. For example, while the salient features of the present invention are directed to a device for warming persons, the blanket could be used equally well to cool individuals. It is therefore contemplated that the appended claims will cover such modifications that fall within the true scope of the invention.
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A convection blanket for warming persons lying thereon. The preferred embodiment has four layers, two outer insulating layers, and two inner layers of metallic foil. The inner metallic layers minimize heat loss across the length of the blanket. A unique pattern of pinholes in the top layers allows a larger volume of warm air to exit the blanket at the end opposite the air supply hose. All layers are stitched intermittently to avoid distension of the blanket, without defining clear channels, assuring uniform distribution of air within the blanket.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority based on U.S. Provisional Patent Application No. 60/203,770, filed May 12, 2000, which is hereby incorporated by reference in full.
FIELD OF THE INVENTION
The present Invention relates to the field of foods and beverages. In particular, the present Invention relates to compositions and methods for preparing foods and beverages using novel peanut powder compositions.
BACKGROUND OF THE INVENTION
The desirability of flavorful foods or beverages that contain high quality protein is well known. In particular, there has been considerable effort directed to the use of nut proteins, such as from peanuts, in such foods. By way of examples only, Watson (U.S. Pat. No. 617,266) mentions manufacturing flour or meal from peanuts for use as foodstuffs or mixing with wheaten flour or other foodstuffs. Mitchell (U.S. Pat. No. 2,511,119) mentions an aqueous peanut emulsion for making foods and drinks. Pominski (U.S. Pat. No. 4,025,658) mentions peanut flour for making peanut milks. Baxley (U.S. Pat. No. 4,113,889) mentions peanut flour for baking or making milk substitutes.
Despite these efforts, there remains a need for novel peanut powder compositions and related food and beverage compositions, particularly those that use cocoa powders. Such compositions may increase agricultural production of peanuts; increase consumption of the more nutritional parts of peanuts; and increase consumption of peanut by-products, while providing desirable foods and beverages to the consuming public.
SUMMARY OF THE INVENTION
The present Invention comprises compositions and methods for preparing foods and beverages using novel peanut powder compositions. In one preferred embodiment, the Invention is comprised of one or more flavorful peanut powder composition that may contain peanut products, sweeteners, or other ingredients. Thus, embodiments of the Invention comprise alternative peanut products that can be used, for example, as foods and beverages that are refreshing, novel, pleasing and nutritious.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present Invention comprises compositions and methods for preparing foods and beverages using novel peanut powder compositions. By way of example only, and without limitation, in one embodiment, the Invention is comprised of a free-flowing powder composition which can be mixed with one or more liquids or solid materials to produce one or more novel foods or beverages. In one embodiment, the Invention is comprised of a novel peanut powder, which may be prepared by the following method, among other methods:
Raw peanuts are obtained and roasted at temperatures not to exceed 300 degrees Fahrenheit for a period of approximately 15 minutes. The peanuts are allowed to remain in the roasters for approximately an additional 5 minutes for cooling. The roasted peanuts are cooled, for example, by passing through a cooling system known to those of ordinary skill in the art, which brings the temperature of peanuts down to approximately 120 to 130 degrees Fahrenheit.
When cooled to the desired temperature, the roasted peanuts are discharged into the gravity separator or destoner, or similar apparatus, the operation of which allows further cooling time and also causes light materials associated with the roasted peanuts to rise and be vacuumed out while heavier materials (like stones and the like) move downward and are discharged. The remaining peanut skins are removed by a blancher, which splits the roasted peanut in half, at which point the skins are aspirated out.
The blanched peanuts are passed over a pick table where more extraneous material is removed manually. The peanuts are also passed through a safe line metal detector that removes ferrous and non-ferrous metals.
A grinder mill then grinds the roasted peanuts to a semi-fine peanut butter paste, by way of example only, to a grind of 8 to 14 mils. A temperature exceeding 165 degrees Fahrenheit is applied at the grinding mill to enhance the killing of any microorganisms.
A high-pressure press is used to press excess peanut oil out of the peanut paste. Different pressures are used to obtain varying degrees of fat content in the peanut powder, as desired. The resulting peanut cake is passed through a crushing device, which pulverizes the cake into a free-flowing powder. Peanut powders may be prepared or obtained by other means known to those of ordinary skill in the art, by way of examples only and without limitation, by obtaining and processing peanut cakes or purchasing suitable peanut powder for blending.
A blender, by way of example only, a ribbon blender, is used to blend the peanut powder with other ingredients as may be desired, for example, with one or more of materials such as fructose, sugar, dextrose, cocoa powder and/or salt). The material is blended, by way of example, for about 5 minutes, the mixing time being consistent as to not affect the finished appearance of the mix. The mix may or may not contain any added artificial flavors or preservatives, as desired. The mix is then ground in a grinder. After grinding, the batch of mix is re-blended for about two minutes, again time being an important factor. The finished blend is then passed through a safeline metal detector, which removes any ferrous and non-ferrous metals.
Thus, the Invention comprises one or more novel peanut powder compositions for use, by way of examples only, by themselves, or mixed with consumable liquids and solids to form foods or beverages containing the peanut powder composition. The following examples further illustrate but do not limit the embodiments of the present Invention.
EXAMPLES OF PEANUT POWDER COMPOSITIONS (in weight percent)
Standard Formula-
Peanut Powder
50-75%
Fructose
15-25%
Sugar
6-10%
Dextrose
2-6%
Cocoa
2-6%
Salt
0.25-1.75%.
Salt Free Formula (no salt added to the mix)-
Peanut Powder
50-75%
Fructose
15-25%
Sugar
6-10%
Dextrose
2-6%
Cocoa
2-6%.
Decreased/Increased Sugar Formula
(sugar content may be varied based on the market targeted)-
Peanut Powder
40-85%
Fructose
0-25%
Sugar
0-16%
Dextrose
0-8%
Cocoa
2-6%
Salt
0.25-1.75%.
Low Fat Formula
(made with a low fat peanut powder, e.g., approximately 12% fat)-
Peanut Powder (low fat approx. 12%)
50-75%
Fructose
15-25%
Sugar
6-10%
Dextrose
2-6%
Cocoa
2-6%
Salt
0.25-1.75%.
Reduced Fat Formula (made with a
reduced fat peanut powder, e.g., approximately 24% fat)-
Peanut Powder (reduced fat approx. 24%)
50-75%
Fructose
15-25%
Sugar
6-10%
Dextrose
2-6%
Cocoa
2-6%
Salt
0.25-1.75%.
Regular Fat Formula (made with
peanut powder with a fat level of approximately 27-37% fat)-
Peanut Powder (approx. 27-37% fat)
50-75%
Fructose
15-25%
Sugar
6-10%
Dextrose
2-6%
Cocoa
2-6%
Salt
0.25-1.75%.
No Cocoa Formula (no cocoa added
to the mix and the amount of peanut powder increased)-
Peanut Powder
50-75%
Fructose
15-25%
Sugar
6-10%
Dextrose
2-6%
Salt
0.25-0.75%.
Fortified Formula—same Standard Formula but with one or more added vitamins and minerals, by way of examples only, Vitamin A, C, B's, K, or others.
Holistic Formula—same Standard Formula but with one or more added herbs, by way of examples only, ginseng, echinacea, gingko biloba, kava kava, St. John's wort, grape seed, or others.
Weight Training Formula—same Standard Formula but with one or more added vitamins and amino acids, which may be beneficial for building muscles, by way of examples only, fumaric acid, L-cystine, L-cysteine HCl, L-leucine, L-tyrosine, mannitol, Vitamins A, C, B's, K, or others.
Weight Loss Formula—same Standard Formula but with one or more added chemicals, which may assist with or enhance weight loss, by way of examples only, white willow bark, ephedrine, caffeine, ginseng, vitamins, minerals, or others.
Vanilla-flavored Formula (cocoa replaced with natural vanilla flavor) -
Peanut Powder
50-75%
Fructose
15-25%
Sugar
6-10%
Dextrose
2-6%
Natural Vanilla Flavor
0.05-4%
Salt
0.25-1.75%
The Invention is further comprised of one or more beverage compositions containing an embodiment of the novel peanut powder composition Invention blended with or in a consumable liquid. The following examples further illustrate but do not limit such embodiments of the present Invention:
EXAMPLE 1
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 8 oz. of water. Either prepared hot or cold.
EXAMPLE 2
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 8 oz. of skim milk. Either prepared hot or cold.
EXAMPLE 3
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 8 oz. of 1% milk. Either prepared hot or cold.
EXAMPLE 4
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 8 oz. of 2% milk. Either prepared hot or cold.
EXAMPLE 5
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 8 oz. of whole milk. Either prepared hot or cold.
EXAMPLE 6
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 1 oz. any type of alcohol (e.g., whiskey, gin, vodka, rye, rum, etc.) 4 oz. of either water, 1%, 2%, skim or whole milk.
EXAMPLE 7
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 8 oz. of carbonated water. Prepared cold.
EXAMPLE 8
1 to 4 tablespoons (9 to 38 grams) of peanut powder composition blended with 8 oz of soya milk. Either prepared hot or cold.
Other embodiments of the present Invention comprise one or more food compositions containing an embodiment of the novel peanut powder composition Invention. By way of example only, and without limitation, one such embodiment is an ice cream product comprised of a peanut powder composition and an ice cream base. Such ice cream bases are well-known to those of ordinary skill in the art and may contain one or more ingredients such as dairy cream, nonfat skim milk, sugars, stabilizers and emulsifiers, and solid additives or fillers (by way of example only, sweet cream buttermilk solids). The following example further illustrates but does not limit such embodiments of the present Invention:
Ice Cream Formula (Peanut powder composition portion may be one or
more of the embodiments, including without limitation, the Standard
Formula and other examples described above) -
Essence of Roasted Peanut Oil
0-15%
Peanut powder composition
2-30%
Ice Cream Base Mix
70 to 98%.
Preferred embodiments of the present Invention have been disclosed. A person of ordinary skill in the art would realize, however, that certain modifications would come within the teachings of this Invention, and the following claims should be studied to determine the true scope and content of the invention. In addition, the compositions and methods of the present Invention can be incorporated in the form of a variety of embodiments, only a few of which are described herein. It will be apparent to the artisan that other embodiments exist that do not depart from the spirit of the Invention. Thus, the described embodiments are illustrative and should not be construed as restrictive.
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A novel peanut powder composition comprising 50-70% by weight peanut powder, 15-25% fructose by weight, 6-10% by weight sugar and 2-6% by weight dextrose is provided wherein the peanut powder can be used in making flavorful foods and beverages.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to cargo vehicles such as fork lift trucks. More particularly, it relates to a deadman brake assembly which automatically works when the driver is not on his seat.
2. Description of the Prior Art
FIG. 5 shows a typical conventional deadman brake provided on a cargo vehicle such as a fork lift truck. As illustrated, the deadman brake assembly comprises a seat supporting plate 2 for supporting a driver's seat 1 and a brake bar 4 of a drum type brake device 3 connected by a link mechanism 5. When the driver is not on the driver's seat 1, the seat supporting plate 2 pivoted on a bracket 7 of a vehicle frame 6 is tilted forward (the direction of the arrow A) as a result of the action of a tension spring 8, and a brake shoe 9 sandwiches a brake drum 10 on both sides thereof to exert a braking action on the brake drum 10. When the driver sits on the driver's seat 1, the seat supporting plate 2 is tilted against the spring force of the tension spring 8 to the position indicated by the dotted chain line so that the brake drum 10 is released from the state in which it is sandwiched by the brake shoe 9.
As will be apparent from the above, in the deadman brake, the driver's seat 1 always has a tendency to tilt forward as a result of the action of the tension spring 8. However, since the tension spring 8 has a maximum tensile force when the driver sits on the driver's seat 1, the lifting force exerted on the driver's seat when the driver sits on the seat is greater than that exerted when the seat is not occupied. This has resulted in problems that, even when the driver sits on the driver's seat, the seat can be shaky during driving depending on the posture of the driver and the driver can have a sense of floating.
SUMMARY OF THE INVENTION
It is therefore a major object of the present invention to provide a deadman brake assembly which can reduce the lifting force exerted on a driver's seat as much as possible when a driver sits on the seat.
In order to achieve the above object, the deadman brake for a cargo vehicle having a vehicle frame and a driver's seat according to the present invention comprises a brake device selectively applying a braking force to said cargo vehicle, means provided for moving between a brake releasing position that the moving means assumes when a driver sits on said driver's seat and a brake applying position that the moving means assumes when the driver is not on said seat, a link mechanism interposed between said moving means and said brake device for connecting them and for effecting the release or application of the brake with said brake device in response to the movement of said moving means, first means connected to said link mechanism for urging said moving means toward said brake applying position through said link mechanism, and second means connected to said link mechanism for urging said moving means toward said brake releasing position through said link mechanism when a driver sits on said driver's seat.
According to a preferred embodiment of the present invention, a deadman brake comprising a seat supporting plate for supporting a driver's seat, which is mounted so that it can be tilted relative to a vehicle frame, a brake device, a link mechanism for connecting said seat supporting plate and a brake lever of said brake device, and a spring means provided in said link mechanism for urging said brake lever in the direction in which the brake is applied is characterised in that said link mechanism incorporates a turnover spring which exerts a spring force in a direction for keeping said seat supporting plate in a state that it enters when the driver sits on said driver's seat and which exerts a spring force in another direction for lifting said seat supporting plate when the driver leaves said driver's seat.
By incorporating the turnover spring as described above, a component of the spring force of said spring means is cancelled when the driver sits on the seat and, as a result, the lifting force acting on the seat supporting plate is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more readily understood by reading the following detailed description of the preferred embodiment thereof made in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic side view showing a deadman brake assembly according to the present invention as a whole;
FIG. 2 is an enlarged partially cut-away view of a part of FIG. 1 showing a state wherein the seat is not occupied (brake applied) for illustrating the action of a turnover spring in a deadman brake of the present invention;
FIG. 3 is an enlarged view similar to FIG. 2 showing a state wherein the seat is occupied (brake released);
FIG. 4 is a graph showing the relationship between the torque action on a bell crank in a deadman brake assembly of the present invention and the position of said bell crank; and
FIG. 5 is a schematic side view showing a conventional deadman brake as a whole.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. Throughout the drawings, like reference numerals indicate like or corresponding parts.
FIG. 1 schematically shows an embodiment of a deadman brake assembly configured according to the present invention. The deadman brake assembly of the present invention has a seat supporting plate 2 formed in a curved L-like shape for supporting a driver's seat 1, a drum type brake device 3 for braking a rotating shaft 12 of a drive motor 11 as needed, and a link mechanism 5 interposed between them for connecting them, just as in the conventional deadman brake described above in conjunction with FIG. 5.
The lower end of the seat supporting plate 2 is supported on a bracket 7 provided under a vehicle frame 6 with a pin 13 so that it can be tilted forward and backward together with the driver's seat 1. One piece of seat supporting plate 2 forms a link 14 extending downwardly from the lower end of the seat supporting plate 2 so that it will swing forward and backward about the pin 13 in response to the movement of the seat supporting plate 2.
One end of a connecting rod 15 is connected to the end the link 14 by a pin 16 to allow the link 14 to swing. The other end of the connecting rod 15 is connected to an intermediate portion of a long arm 19 of a bell crank 18 by a pin 17. The bell crank 18 is pivoted on a support bracket 20 secured to the vehicle frame 6 by a shaft 21. The end of a short arm 22 of the bell crank 18 is connected to the end of a brake lever 4 of the brake device 3 through a connecting rod 23.
As will be apparent from FIGS. 2 and 3, a support pin 24 is attached to the end of the long arm 19 of the bell crank 18, and one end of a tension coil spring 8 engages with the support pin 24. The other end of the tension spring 8 is attached to a support piece 25 on the vehicle frame 6. In a no-load condition, the tension spring 8 causes the bell crank 18 to rotate to the position indicated by a solid line in FIG. 1 (the state shown in FIG. 2), causes the brake lever 4 to tilt in a direction such that the brake shoe 9 will sandwich the brake drum 10, and causes the seat supporting plate 2 and driver's seat 1 to incline through the connecting rod 15 and link 14 so that they will float above a support base 26.
In the illustrated embodiment of the present invention, a turnover spring assembly 30 is interposed between the support pin 24 of the long arm 19 of the bell crank 18 and the support bracket 20. The turnover spring assembly 30 comprises a compression coil spring 31, and retaining members 32 and 33 provided in a sliding relationship with each other so that they will sandwich said compression coil spring 31 on both sides thereof. The first retaining member 32 having a shaft portion 32a is pivoted on the support pin 24, and the second retaining member 33 having a cylindrical portion 33a slidably receiving said shaft portion 32a is pivoted on a support shaft 34 on the support bracket 20. As shown in FIG. 1, the support shaft 34 is centered on the line connecting a point 35 which is substantially in the middle of the locus that the center of the support pin 24 on said bell crank describes when the bell crank 18 rotates from the position indicated by the solid line to the position indicated by the dotted line and the center of the shaft 21 pivotally supporting the bell crank 18. In addition, the center of the support shaft 34 is in a position such that the compresion coil spring 31 is compressed to the extreme when the support pin 24 is on the point 35.
In such a configuration, when the driver is not on the driver's seat 1 the bell crank 18 is pulled in the direction of the arrow B by the tension spring 8. Therefore, the seat supporting plate 2 and driver's seat 1 are kept in a floating state through the connecting rod 15 and link 14 and the brake shoe 9 of the brake device 3 sandwiches the brake drum 10 to exert a braking force on the rotating shaft 12 of the drive motor 11. At this time, the turnover spring assembly 30 exerts an urging force f 1 on the support pin 24 as shown in FIG. 2. A component force f 1 ' of the urging force f 1 in a direction tangential to said locus of the support pin 24 acts downwardly to urge the bell crank 18 in the direction of the arrow B. This force, along with the tensile force f 2 of the tension spring 8, exerts a large downward torque on the bell crank 18.
On the other hand, when the driver sits on the driver's seat 1, the seat supporting plate 2 rotates backward (clockwise in FIG. 1) about the pin 13, and the link 14 and connecting rod 15 move forward to rotate the bell crank 18 in the direction of the arrow C. Thus, the state as indicated by the dotted chain line in FIG. 1 and shown in FIG. 3 is realized. In this state, the brake lever 4 of the brake device 3 is pulled down through the connecting rod 23 as a result of the operation of the bell crank 18. This separates the brake shoe 9 from the brake drum 10 to release the brake. In the period of time immediately after the seat is occupied, the compression spring 31 of the turnover spring assembly 30 is gradually compressed as the bell crank 18 is rotated and enters a state wherein it is compressed to the extreme at the point 35. If the bell crank 18 is further rotated, the direction in which the spring force of the turnover spring assembly 30 acts changes to the direction in which the bell crank 18 is urged in the direction of the arrow C. Finally, the state shown in FIG. 3 is realized. In this state, in a direction tangential to said locus of the support pin 24, a component force f' 3 of the spring force f 3 of the turnover spring assembly 30 acts in the direction opposite to that of a component force f' 4 of the tensile force f 4 of the tension spring 8. Thus, the torque that the bell crank 18 receives is reduced compared with that in the case where the turnover spring assembly 30 is not provided. Accordingly, the lifting force exerted on the driver's seat 1 by the bell crank 18 through the connecting rod 15, link 14 and seat supporting plate 3 is also suppressed.
FIG. 4 is a graph showing the relationship between the position of the bell crank 18 (the angle thereof relative to the position at the time when the brake is actuated) and the torque acting on the bell crank 18. It will be understood also from this figure that the torque acting on the bell crank 18, i.e., the lifting force acting on the driver's seat 1 is fixed by providing the turnover spring assembly 30.
In light of the function of the turnover spring assembly 30, the torque acting on the bell crank 18 must always be in the direction of the arrow B. Therefore, the torque provided when the turnover spring assembly 30 is in the state shown in FIG. 3 must be smaller than the torque provided by the tension spring 8.
As described above, in the deadman brake according to the present invention, the lifting force acting on the driver's seat when the drive sits on the seat is suppressed. This results in improved stability preventing the driver's seat from being shaky during driving and suppresses the feeling of floating allowing more comfortable driving.
Further, when the seat is not occupied, the turnover spring as well as the tension spring cause the brake lever of the brake device to tilt in the same direction. As a result, a more reliable brake operation can be performed.
In the drawings and description, there has been disclosed a typical preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of limitation. Numerous variations can be made within the spirit and scope of the invention as described in the foregoing description and defined in the appended claims. For example, although the turnover spring assembly is mounted on the bell crank in the above-described embodiment, the mounting position may be appropriately changed depending on the configuration of the link mechanism. Further, the turnover spring assembly is not limited to the compression spring type, and those comprising a torsion coil spring, tension spring, or the like may be used.
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A deadman brake assembly incorporating a turnover spring in a link mechanism thereof to exert a spring force in a direction in which a seat supporting plate is kept in a state it enters when a driver sits on the driver's seat and to exert the spring force in another direction in which the seat supporting plate is lifted when the driver leaves the driver's seat, suppressing as much as possible the lifting force acting on the driver's seat when the driver sits thereon.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a process for preparing from a tertiary ether a corresponding tertiary olefin. More particularly, the present invention relates to a process for preparing a tertiary olefin having a high purity in a high yield from a tertiary ether by using a novel catalyst.
(2) Description of the Prior Art
Tertiary olefins have industrially been prepared from C 4 -fractions containing tertiary olefins according to the sulfuric acid extraction process. However, this sulfuric acid extraction process is defective in that since the apparatus is corroded by the concentrated sulfuric acid used, an expensive material should be used for the apparatus and that a tertiary olefin is consumed for side reactions such as polymerization and hydration during the extraction with concentrated sulfuric acid. Therefore, this process is not advantageous from an economical viewpoint.
Recently, in U.S.A. and European countries, methyl-t-butyl ether (hereinafter referred to as "MTBE") is produced in large quantities as an octane number booster for gasoline, and there is a strong indication of the production of MTBE in Japan and there is a good possibility that MTBE will be available at a cost as low as that of gasoline. In this case, it is expected that a process for preparing isobutylene by decomposition of MTBE will become very advantageous over the sulfuric acid extraction process.
As one premise for realizing this process, it is necessary that the decomposition reaction of MTBE should be advanced at a high conversion (high decomposition ratio) with a high selectivity, and it is preferred that isobutylene and methanol obtained as decomposition products should have a high enough purity for them to be used as industrial materials.
A tertiary olefin such as isobutylene is industrially valuable as a starting material of, for example, methyl methacrylate or a butyl rubber polymer. In the latter case, it is required that the purity of isobutylene should be especially high.
Several processes have heretofore been proposed for preparing tertiary olefins from tertiary ethers. For example, Japanese Patent Publication No. 41882/72 discloses a process in which MTBE is decomposed by using a γ-alumina type acidic solid catalyst having a specific surface area of at least 25 m 2 /g, Japanese Patent Application Laid-Open Specification No. 39604/76 proposes a process using as a catalyst activated alumina modified by reaction with a silicon compound, Japanese Patent Application Laid-Open Specification No. 2695/80 discloses a process using a catalyst comprising silica as the main component and various metal oxides combined therewith, Japanese Patent Application Laid-Open Specification No. 94602/74 proposes a process using an active carbon catalyst, Japanese Patent Publication No. 26401/76 teaches a process using a metal sulfate as a catalyst, Japanese Patent Application Laid-Open Specification No. 85323/82 proposes a process in which an aluminum-containing silica catalyst formed, for example, by supporting aluminum sulfate on a silica carrier is used and water and/or a tertiary alcohol is added to the reaction system, Japanese Patent Application Laid-Open Specification No. 75934/82 proposes a process using a catalyst formed by supporting an aluminum compound such as aluminum sulfate on silica and heating and calcining them at a temperature higher than the decomposition temperature of the aluminum compound, Japanese Patent Application Laid-Open Specification No. 102821/82 proposes a process in which the decomposition is carried out in the presence of steam by using a catalyst comprising titanium, hafnium or zirconium supported on alumina, Japanese Patent Application Laid-Open Specification No. 123124/82 teaches a process using an acidic molecular sieve as the catalyst, Japanese Patent Application Laid-Open Specification No. 134421/82 proposes a process using a catalyst formed by supporting a metal sulfate on a carrier which has been calcined at a high temperature, and Japanese Patent Application Laid-Open Specification No. 142924/82 teaches a process using a catalyst formed by supporting an aluminum compound on a carrier containing silicon oxide and heating and calcining them at a temperature higher than the decomposition temperature of the aluminum compound.
These known processes, however, are defective in various points. For example, since an ether such as dimethyl ether is formed as a by-product by dehydration of two molecules of a methanol formed by the decomposition of MTBE, the alcohol recovery ratio is low. Furthermore, the reaction temperature is very high and the preparation of catalysts is troublesome, and expensive chemicals should be used. Moreover, the catalyst life is short and the durability is insufficient. Thus, none of the catalysts heretofore proposed are industrially satisfactory.
Since the reaction of forming a tertiary olefin by decomposition of a tertiary ether is an endothermic reaction, from the energy-saving viewpoint, it is desirable that a high decomposition ratio of the tertiary ether and a high selectivity to the tertiary olefin and alcohol should simultaneously be attained at a low temperature level.
SUMMARY OF THE INVENTION
We made research with a view to overcoming the above-mentioned defects of the conventional techniques and developing an industrially valuable catalyst being excellent in the decomposition activity at low temperature and in the selectivity, having a good reproducibility, being prepared at a low cost and having a long life and a good stability. As the result, we have now completed the present invention.
More specifically, in accordance with the present invention, there is provided a process for the preparation of tertiary olefins which comprises catalytically decomposing a tertiary ether to a tertiary olefin, wherein the catalytic decomposition of the tertiary ether is carried out in the presence of a solid phosphoric acid catalyst which has been calcined at a temperature of at least 500° C. in an inert gas.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Any of tertiary ethers mentioned above can be used in the present invention without any particular limitation. However, tertiary ethers represented by the following general formula are ordinarily used: ##STR1## wherein R 1 , R 2 and R 3 , which may be the same or different, stand for an alkyl group having 1 to 4 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, such as a methyl, ethyl or isopropyl group, and R 4 stands for an alkyl group having 1 to 3 carbon atoms, preferably a methyl, ethyl or isopropyl group.
Typical examples of the tertiary ether represented by the above general formula and tertiary olefins prepared therefrom are described below.
______________________________________Tertiary Ethers Tertiary Olefins______________________________________ ##STR2## ##STR3## ##STR4## ##STR5## ##STR6## ##STR7## ##STR8## ##STR9## ##STR10## ##STR11## ##STR12## ##STR13##______________________________________
Of the foregoing tertiary ethers, MTBE, methyl-t-amyl ether and ethyl-t-butyl ether are preferred as industrial starting materials.
The process for the preparation of these ethers is not particularly critical. For example, in case of MTBE, it is possible to use MTBE prepared from isobutylene having a high purity and methanol having a high purity. However, use of MTBE prepared from a C 4 -fraction containing isobutylene and methanol is preferred and industrially significant. More specifically, the process in which MTBE is isolated from the reaction product between the C 4 -fraction containing isobutylene and methanol by such purification means as distillation and this MTBE is decomposed into isobutylene and methanol can be regarded as the process for subjecting the C 4 -fraction to extraction with methanol to recover isobutylene. In short, this process can be an excellent process for purifying isobutylene.
The solid phosphoric acid catalyst used in the present invention is a catalyst formed by supporting a phosphoric acid component such as orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid or polyphosphoric acid (triphosphoric acid or tetraphosphoric acid) on a carrier containing a metal oxide. As typical examples of the carrier, there can be mentioned diatomaceous earth, aluminum oxide, zirconium oxide, titanium oxide, thorium oxide, acid clay, activated clay, silica-alumina and zeolite. The carriers may be used singly or in the form of a mixture of two or more of them. These carriers are ordinarily used in the untreated state, but products formed by calcining these carriers according to customary procedures can also be used. A process comprising supporting phosphoric anhydride (P 2 O 5 ), orthophosphoric acid (H 3 PO 4 ) or ammonium phosphate [(NH 4 ) 3 PO 4 ] per se or in the form of an aqueous solution on a carrier such as mentioned above and calcining is preferably adopted for the production of the catalyst. By calcination, the beforementioned phosphorus compound is partially or entirely converted to pyrophosphoric acid, metaphosphoric acid or polyphosphoric acid.
The solid phosphoric acid catalyst used in the present invention may further comprise a metal such as nickel, copper, cobalt, iron, zinc, chromium, manganese, titanium or vanadium or an oxide thereof in order to improve catalyst physical properties such as heat-conductivity, strength, attrition resistance and bulk density.
In the present invention, the lower limit of the calcination temperature is 500° C., preferably 600° C., especially preferably 700° C., but the upper limit is not particularly critical. However, the upper limit of the calcination temperature is 1200° C., preferably 1150° C., especially preferably 1100° C. If the calcination temperature is lower than 500° C., a catalyst having a sufficient activity and a long life cannot be obtained. Furthermore, after deposition of phosphoric acid on the carrier but before calcination conducted at a temperature not lower than 500° C., drying and/or low temperature calcination may be carried out at room temperature or an elevated temperature lower than 500° C. to remove a part or all of the solvent such as water, contained in the phosphoric acid-supported carrier, and this drying and/or low temperature calcination is preferred.
The calcination time is changed according to the amount supported of phosphoric acid, the calcination temperature and the kind of the carrier and is not generally defined. However, a calcination time of 0.5 to 50 hours is ordinarily sufficient. Generally, as the calcination temperature is high, the calcination time may be shortened.
The calcination is carried out in an atmosphere of an inert gas such as air, nitrogen, helium, argon, steam or a mixture thereof. From the practical viewpoint, it is most preferred that the calcination be carried out in air.
As means for depositing phosphoric acid on the carrier, there can be adopted a method comprising spraying commercially available 85% phosphoric acid or a solution formed by dissolving this phosphoric acid in a solvent such as water on the carrier, a method comprising dipping the carrier in a solution of phosphoric acid and drying the carrier, a method comprising dipping the carrier in commercially available phosphoric acid or a solution thereof and subjecting to suction filtration or centrifugal separation, and other customary methods.
The amount of phosphoric acid supported on the carrier (expressed as the amount of P 2 O 5 ; the same will apply hereinafter) is changed according to the kind of the carrier and is not generally defined. From the practical viewpoint, however, the amount of phosphoric acid supported on the carrier is ordinarily adjusted to 0.5 to 200 parts by weight, preferably 1 to 100 parts by weight, per 100 parts by weight of the carrier.
The reaction of the present invention may be carried out batchwise or in a continuous manner. Ordinarily, the gas phase reaction of the fixed bed system is preferably adopted. Other systems such as the fluidized bed system may also be adopted.
The reaction is carried out at a temperature of 100° to 400° C., preferably 130° to 350° C.
The reaction pressure is not particularly critical, but ordinarily, the reaction is carried out under a pressure of from atmospheric pressure to 30 Kg/cm 2 , preferably from atmospheric pressure to 10 Kg/cm 2 .
The reaction time is changed according to the reaction temperature and the kind of the catalyst and is not generally defined. For example, in the continuous process, the weight hourly space velocity of the tertiary ether per unit volume of the catalyst (WHSV, g/ml of catalyst/hr; the same will apply hereinafter) is 0.3 to 100 g/ml/hr, preferably 0.5 to 30 g/ml/hr.
Steam may be present in the reaction system, and the presence of steam in the reaction system is preferred. The molar ratio of steam to the tertiary ether (H 2 O/tertiary ether molar ratio), what is called, the steam ratio, is in the range of from 0.05 to 30, preferably from 0.1 to 20.
The catalyst of the present invention has a very long life. When the activity of the catalyst is reduced, the catalyst can easily be regenerated by heating the catalyst at a temperature higher than the reaction temperature in the presence of an inert gas such as helium, nitrogen, steam or air, and the life of the catalyst can be prolonged. It is preferred that the regeneration temperature be higher by at least 50° C. than the reaction temperature but be lower than 1100° C. It is ordinarily preferred that the high temperature inert gas be passed through the catalyst bed for the regeneration. The high temperature inert gas to be used for the regeneration may be obtained by heating the inert gas outside the catalyst bed in advance or by heating the inert gas inside the catalyst bed together with the catalyst.
The catalyst used in the present invention is prepared very simply at a low cost, and the life of the catalyst is long and the catalyst can be regenerated very easily. Furthermore, the conversion of the tertiary ether is high and the selectivities to the tertiary olefin and the alcohol are high, and the tertiary olefin having a high purity can be obtained at a high efficienty even at a low reaction temperature. Accordingly, the present invention is of great industrial importance.
The present invention will now be described in detail with reference to the following Examples that by no means limit the scope of the invention.
EXAMPLES 1 THROUGH 6
60 g of diatomaceous earth, 10 g of titanium dioxide, 35 g of commercially available 85% orthophosphoric acid and 100 g of water were sufficiently mixed, and the mixture was dried below 100° C., calcined at 200° C. for 1 hour, pulverized to a size of 14 to 32 mesh, calcined at a high temperature shown in Table 1 and then charged in a stainless steel reaction vessel.
MTBE was decomposed under a reaction pressure of 5 Kg/cm 2 in the presence or absence of steam.
The obtained results are shown in Table 1.
TABLE 1__________________________________________________________________________ Example No. 1 2 3 4 5 6__________________________________________________________________________Calcination temperature 900 1000 800 900 900 1100(°C.)Calcination time (hours) 18 10 24 18 18 2Steam ratio (H.sub.2 O/MTBE molar 5 5 5 2 no 5ratio) steamReaction temperature (°C.) 190 190 190 190 240 190WHSV (g/ml/hr) 4 4 4 4 4 4Conversion (%) MTBE 99.7 99.6 99.8 99.9 98.9 99.2Selectivities (&)isobutylene 99.5 99.6 99.5 99.6 99.1 99.7di-isobutylene 0.05 0.01 0.1 0.15 0.8 0.01t-butanol 0.45 0.39 0.4 0.25 0.1 0.29methanol 100 100 100 100 99.8 100dimethyl ether 0 0 0 0 0.2 0__________________________________________________________________________
From the foregoing experimental results, it will readily be understood that the effects of the present invention can be increased when a solid phosphoric acid catalyst calcined at a high temperature is used, and that the effects can further be enhanced when steam is present in the reaction system.
EXAMPLE 7
A commercially available silica carrier (N-608 supplied by Nikki Kagaku) was pulverized to a size of 14 to 32 mesh. Then, 70 g of this silica carrier was dipped in an aqueous solution containing 35 g of commercially available 85% orthophosphoric acid, and water was evaporated at a temperature lower than 100° C. and calcination was conducted at 200° C. for 1 hour and at 900° C. for 18 hours. A stainless steel reaction vessel was charged with 13 ml of the so-obtained catalyst.
MTBE was supplied at WHSV of 4 g/ml/hr under conditions of a steam ratio of 5.0, a reaction pressure of 5.0 Kg/cm 2 and a reaction temperature of 201° C. The conversion of MTBE was 99.6%, the selectivity to isobutylene was 99.2%, the selectivity to di-isobutylene was 0.2%, the selectivity to t-butanol was 0.6%, and the selectivity of methanol was 100%. Formation of dimethyl ether was not observed at all.
EXAMPLES 8 THROUGH 14
Commercially available silica-alumina (N-631L supplied by Nikki Kagaku) was pulverized to a size of 14 to 32 mesh. Then, 85 g of this silica-alumina was dipped in an aqueous solution containing 18 g of commercially available 85% orthophosphoric acid, dried below 100° C., calcined at 200° C. for 1 hour and then calcined at a high temperature of 1000° C. for 6 hours. A stainless steel reaction tube was charged with 13 ml of the so-prepared catalyst.
MTBE was decomposed in the presence of steam by changing the steam ratio, reaction temperature, reaction pressure and WHSV.
The obtained results are shown in Table 2.
TABLE 2__________________________________________________________________________ Example No. 8 9 10 11 12 13 14__________________________________________________________________________Reaction pressure (Kg/cm.sup.2) 5 5 5 atmospheric pressure 5 5Reaction temperature (°C.) 200 200 200 200 220 210 190Steam ratio 7 5 3 5 5 7 7WHSV (g/ml/hr) 4 4 4 4 6 5 4Conversion (%) of MTBE 99.7 99.8 99.8 99.8 99.7 99.8 99.5Selectivities (%)isobutylene 99.4 99.5 99.5 99.6 99.5 99.5 99.4di-isobutylene 0.1 0.1 0.2 0.1 0.2 0.1 0.1t-butanol 0.4 0.4 0.3 0.3 0.3 0.4 0.5methanol 100 100 100 100 100 100 100dimethyl ether 0 0 0 0 0 0 0__________________________________________________________________________
EXAMPLE 15
The catalyst life test was carried out under the same reaction conditions as adopted in Example 13 by using the same catalyst as used in Example 13.
The obtained results are shown in Table 3.
TABLE 3______________________________________Reaction SelectivityTime Conversion (%) (%) to Iso- Selectivity(hours) of MTBE butylene (%) to Methanol______________________________________ 6 99.8 99.5 100142 99.8 99.5 100480 99.6 99.5 100801 99.5 99.6 1001007 99.3 99.6 1002100 98.8 99.7 1004005 98.3 99.7 100______________________________________
From the results shown in Table 3, it will readily be understood that the catalyst of the present invention exerts excellent conversion and selectivity over a long period.
EXAMPLE 16
The reaction was carried out in the same manner as in Example 8 except that ethyl-t-butyl ether was used instead of MTBE. The conversion of ethyl-t-butyl ether was 99.5%, the selectivity to isobutylene was 99.5%, the selectivity to di-isobutylene was 0.1%, the selectivity to t-butanol was 0.4%, and the selectivity to ethanol was 100%. Formation of diethyl ether was not observed at all.
COMPARATIVE EXAMPLE 1
The same catalyst as prepared in Examples 1 through 6 was calcined at 400° C. for 18 hours and charged in a stainless steel reaction tube, and the reaction was carried out under conditions of a steam ratio of 5, a reaction temperature of 190° C., WHSV 4.0 g/ml/hr and a reaction pressure of 5.0 Kg/cm 2 . The conversion of MTBE was 98.0%, the selectivity to isobutylene was 98.5%, the selectivity to di-isobutylene was 1.0%, the selectivity to t-butanol was 0.5%, the selectivity to methanol was 99.5%, and the selectivity to dimethyl ether was 0.5%.
COMPARATIVE EXAMPLE 2
By using the same catalyst as prepared in Example 15, the catalyst life test was carried out in the same manner as described in Example 15 except that the calcination temperature was changed to 400° C. and the calcination time was changed to 24 hours.
The obtained results are shown in Table 4.
TABLE 4______________________________________Reaction Selectivity SelectivityTime Conversion (%) (%) to Iso- (%) to(hours) of MTBE butylene Methanol______________________________________ 6 99.0 98.7 99.5140 98.7 98.8 99.6500 95.0 99.3 99.9______________________________________
COMPARATIVE EXAMPLE 3
Commercially available silica-alumina (N-631L supplied by Nikki Kagaku) was pulverized to 14 to 32 mesh. This silica-alumina was calcined at 1000° C. for 6 hours. A stainless steel reaction tube was charged with 13 ml of this silica-alumina.
The reaction was carried out at a steam ratio of 5, a reaction pressure of 5 Kg/cm 2 and a reaction temperature of 200° C. while maintaining WHSV of MTBE at 1.5 g/ml/hr. The conversion of MTBE was 91.0%.
From this result, it is seen that the solid phosphoric acid catalyst of the present invention has a very high effect.
COMPARATIVE EXAMPLE 4
Commercially available silica-alumina (N-631L supplied by Nikki Kagaku) was calcined at 1000° C. for 6 hours, and by using this silica-alumina as the catalyst, the reaction was carried out under the same conditions as described in Example 15.
The obtained results are shown in Table 5.
TABLE 5______________________________________Reaction SelectivityTime Conversion Selectivity (%) (%) to(hours) (%) of MTBE to Isobutylene Methanol______________________________________ 10 94.5 99.4 100138 94.3 99.4 100480 94.0 99.5 100750 93.2 99.6 1001001 90.6 99.6 100______________________________________
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Disclosed is a process for the preparation of tertiary olefins which comprises catalytically decomposing a tertiary ether to a tertiary olefin, wherein the catalytic decomposition of the tertiary olefin is carried out in the presence of a solid phosphoric acid catalyst which has been calcined at a temperature of at least 500° C. in an inert gas.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 09/316,088 filed May 21, 1999, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The principal utility of the invention is with valve and actuator applications where extremely fast response is very desirable. For example, a piston engine that needs to introduce fuel through direct injection within 30 degrees of crank rotation and that is running at 4000 rpm, has 1.25 milliseconds to open the fuel injection valve, inject the fuel and close the valve. The most apparent field of application is in internal-combustion engines for motor vehicles.
2. Description of the Prior Art
The growing utilization of automobiles has greatly added to the atmospheric concentration of various pollutants including oxides of nitrogen and greenhouse gases such as carbon dioxide. In a quest for approaches which could significantly improve the efficiency of fuel utilization for automotive powertrains, while still achieving low levels of NOx emissions, the need for fast valves and actuators became apparent and this invention was conceived.
Conventional “fast” valves begin a valving change from either an open or closed position. In the closed position the “movable component” of the valve has “sealed” (usually against a seat or, in a spool valve, by positioning the spool so that flow from the high pressure port is blocked). A command to open results in a force being applied to the movable component, and movement (i.e., acceleration) of the mass of the movable component begins according to the following equation: F M = a
Where:
“F” is the force applied to the movable component
“M” is the mass of the movable component
“a” is the acceleration of the movable component that results
The time required to move the movable component from the closed position to the fully open position is the time needed for valve opening, and this time is dependent on the acceleration and the distance the movable component must cover from the closed position to the fully open position. Conventional “fast” valves maximize acceleration by applying a very large force, minimize the mass of the movable components and minimize the travel distance by valve design to the extent possible. Extremely fast valve action (e.g., less than 1 millisecond) is therefore very difficult to achieve with conventional designs. Conventional valve designs begin the opening stage with an initial speed of zero. The acceleration rate results in a maximum speed that occurs at the end of the opening process. The average speed is therefore determined by the initial speed (i.e., zero) and the final speed, and for a near constant acceleration rate the average speed is about one half the final speed. Since the time for opening a conventional valve is the distance needed for travel to fully open the flow ports divided by the average speed, starting the valve opening from zero speed severely constrains the ability to obtain very fast valve openings.
In a conventional spool valve the “OFF” position has the spool valve port slightly withdrawn from communication with the passage through the valve body in order to provide a seal against leakage. See, for example, U.S. Pat. No. 4,770,389 issued to Bodine. This conventional sealing distance is not intended to allow the valve spool to accelerate prior to starting to open and, in fact, acceleration through a sealing zone in a conventional valve is de minimus, i.e., to less than 10% of maximum spool velocity.
In some modern “fast acting valves”, the leading edge of the valve port and that of the valve body passage are “line-on-line” in the OFF position. In other words, the leading edges of the two ports are radially aligned with no sealing distance therebetween. In such valves some small amount of leakage is tolerated in order to provide a faster acting valve.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a valve mechanism which starts the valve port opening at a high initial speed and finishes the port opening near or above this high initial speed then goes through a deceleration zone, thus significantly reducing the time required for opening (and closing) the valve.
Another object of the present invention is to achieve the above-stated objective by a unique valve design which provides acceleration and deceleration zones to provide extremely fast valve opening and closing.
A third object of the present invention is provision of a unique, two-way spool valve incorporating the desired acceleration/deceleration features described above.
A fourth object of the present invention is provision of a unique, three-way spool valve incorporating the desired acceleration/deceleration features described above.
A fifth object of the present invention is provision of a unique control valve for a two-way actuator incorporating the desired acceleration/deceleration features.
A sixth object of the present invention is provision of a unique, two-way cartridge valve incorporating the desired acceleration/deceleration features.
A seventh object of the present invention is provision of a unique fuel injection (or fluid control) system utilizing two valves, having the desired acceleration/deceleration characteristics, for each injector and an appropriately sized high pressure fuel supply line, or line with a flow restrictor such as an orifice.
An eighth object of the present invention is provision of a unique gas flow control valve which a control valve having the desired acceleration/deceleration characteristics, a fast, hydraulic actuator and, integrated with the hydraulic actuator, a poppet valve also having the acceleration/deceleration characteristics of the present invention.
A ninth object of the present invention is provision of a new means for utilizing multiple solenoids in series to maximize and maintain the accelerating force on the movable component (valve member).
A tenth object of the present invention is provision of a unique solenoid actuated valve providing the acceleration/deceleration characteristics of the present invention.
The unique design and operation of this new valve are based on utilization of acceleration and deceleration zones to achieve very fast valve response. The valve provides a zone (i.e., distance) wherein the movable component can be accelerated to a high speed of at least 30% of its maximum velocity before the movable component starts the valve port opening. Therefore, the valve port opening occurs in the shortest time possible. A second zone (i.e., distance) is provided for deceleration of the movable component and this second “deceleration” zone also serves as the acceleration zone for the reverse action of the valve (i.e., closing).
More specifically, in one embodiment the present invention provides a fast-acting valve including a valve body and a valve spool slidably mounted in a bore within the valve body for reciprocating movement in a linear path between first and second limit (rest) positions, i.e. between fully closed and fully open positions. The valve body and the valve spool both have at least one flow passage which align in the valve open position. The flow passage through the valve body is spaced from the one spool fluid flow passage with the valve spool in the fully closed position by a distance including an acceleration zone and a deceleration zone. The acceleration zone may be defined as the distance through which the valve spool accelerates before the one spool fluid flow passage reaches a position initiating fluid communication between it and the one valve body flow passage, i.e. a position where the leading edge of valve spool flow passage enters the one valve body flow passage, whereby the flow passage is very quickly opened. This acceleration zone is significantly longer than the distance required for sealing. The deceleration zone is the distance through which the valve spool decelerates before coming to rest in the fully open position. The fact acting valve of the present invention further includes first and second acceleration/deceleration means for alternately accelerating and decelerating the valve spool in travel between the fully open and fully closed rest positions. An additional drive means is provided in several embodiments for imparting the reciprocating movement to the valve spool. In one preferred embodiment springs or elastic members are mounted within opposing ends of the valve body bore and are compressed by the valve spool at the first and second limit positions, respectively. In this preferred embodiment, the acceleration and deceleration zones are equal in length to the distance a spring extends between a compressed state with the valve spool bearing against it in one of the fully closed and fully open positions and a relatively relaxed state with the valve spool in the other of the fully closed and fully open positions. This embodiment requires a separate motive means or actuator for driving the valve spool with the reciprocating movement and for holding the valve spool against the spring (or other elastic member) in its compressed state. An electromagnetic actuator would include at least one solenoid mounted at each end, surrounding the bore of the valve body.
Preferably, the acceleration zone will be a length through which the spool accelerates to a velocity at least 30% and, more preferably, at least 50% of maximum spool velocity.
In a further preferred embodiment at least two solenoids are mounted at opposing ends of the valve body, surrounding ends of the bore. In this embodiment the solenoids at one end would be energized in succession to accelerate the valve spool while the solenoids at the opposite end would be energized in succession to decelerate the valve spool.
The path through which the valve spool travels may include a gap between acceleration and deceleration zones. Toward this end the diameter of the valve body flow passage may be significantly larger than that of the flow passage through the valve spool.
In one preferred embodiment the valve body is further provided with a balancing chamber open to the valve spool at a position where the valve spool is diametrically opposed to the valve body inlet so that the force of the inlet pressure, tending to push the valve spool against one side of the bore is offset by pressure within the balancing chamber to negate the force at the valve body inlet. A conduit provides for fluid communication between the inlet to the valve body and the balancing chamber.
In other preferred embodiments the valve spool and the valve body are each provided with plural fluid passages which are selectively opened and closed as the valve spool slides relative to the valve body.
In another preferred embodiment the fast-acting valve of the present invention is in the form of a poppet valve for mounting in the head of a combustion chamber to control inlet of a fuel/air mixture or outlet of an exhaust gas.
In yet another preferred embodiment the fast-acting valve of the present invention is a cartridge valve which may be utilized in series with a fuel injection nozzle to form a fuel injection system.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1A is a cross-sectional view of a valve according to a first embodiment of the present invention in its “OFF” (closed) position; and FIG. 1B is a cross-sectional view of the valve of FIG. 1A in its “ON” (open) position;
FIG. 2 is a cross-sectional view of a valve according to a second embodiment of the present invention in its closed position;
FIG. 3 is a cross-sectional view of a valve according to a third embodiment of the present invention in its open position;
FIG. 4A is a cross-sectional view of a valve according to a fourth embodiment of the present invention in its “OFF” (closed) position; and FIG. 4B is a cross-sectional view of the valve of FIG. 4A in its “ON” (open) position;
FIG. 5A is a cross-sectional view of a valve according to a fifth embodiment of the present invention in its “OFF” (closed) position; and FIG. 5B is a cross-sectional view of the valve of FIG. 5A in its “ON” (open) position;
FIG. 6A is a cross-sectional view of a valve according to a sixth embodiment of the present invention in its “OFF” (closed) position; and FIG. 6B is a cross-sectional view of the valve of FIG. 6A in its “ON” (open) position;
FIG. 7A is a cross-sectional view of a valve according to the seventh embodiment of the present invention in its “OFF” (closed) position; and FIG. 7B is a cross-sectional view of the valve of FIG. 7A in its “ON” (open) position;
FIG. 8 is a cross-sectional view of a valve according to the eighth embodiment shown in FIGS. 7A and 7B;
FIG. 9A is a cross-sectional view of a valve according to a ninth embodiment of the present invention; and FIG. 9B is a schematic diagram of a fuel injection system including two valves in accordance with the ninth embodiment illustrated in FIG. 9 A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A and 1B illustrate a first embodiment of the present invention. As shown in FIGS. 1A and 1B, the major components of the acceleration/deceleration spool valve 10 are the valve block 12 having an axial bore 12 a, the slidable valve spool 2 , solenoids 3 a and 3 b, fluid supply port 4 , fluid discharge port 6 , spool flow passage 9 and energy absorbing springs 7 a and 7 b.
FIG. 1A shows the spool 2 in its no-flow (“OFF”) position. Pressurized fluid is present in fluid supply port 4 but is unable to flow to fluid discharge port 6 because flow passage 8 is blocked by the spool 2 . Solenoid 3 a is holding spool 2 in this position to offset the force of compressed spring 7 a. When a command to open the valve is given, solenoid 3 a terminates its holding force; solenoid 3 b is activated to generate a force on the spool 2 and, in combination with the force being applied by spring 7 a, initiates acceleration of the spool 2 from its leftmost position to the right. The spool 2 is accelerated through the first zone 14 which serves as an acceleration zone in movement toward opening and through which the spool accelerates to at least 30% of its maximum velocity and, more preferably to at least 50% of maximum velocity. In experimental tests spool speeds of over 90%, even 98% and 99%, maximum have been achieved prior to start of valve opening. Thus, the spool flow passage 9 reaches the leading edge of flow passage 8 traveling at a high speed and the valve opening event occurs very quickly. As spool 2 continues traveling to the right, it engages the energy absorbing spring 7 b and begins its deceleration as the leading edge of flow passage 9 enters deceleration zone 15 . Movement of spool 2 terminates as the leading edge of spool flow passage 9 reaches the trailing edge of flow passage 8 , at the position shown in FIG. 1 B. To terminate fluid flow, the reverse process is employed. Solenoid 3 b is disengaged, solenoid 3 a is engaged and the spool 2 begins acceleration from the rightmost position shown in FIG. 1B to the leftmost position shown in FIG. 1 A. The acceleration zone to terminate fluid flow is zone 16 in FIG. 1 B.
In a second embodiment, as depicted in FIG. 2, multiple solenoids 3 c , 3 d , 3 e , 3 f are used in series, with 3 c and 3 d at one end 3 e and 3 f at the other, to maximize the accelerating force on the spool through its entire acceleration zone. In this second embodiment, to accelerate spool 2 to the right, solenoid 3 e is energized and acts on that part 2 a of spool 2 which responds to the magnetic force. Solenoid 3 d may also be energized to maximize the initial force on the spool as it acts on part 2 b of spool 2 . As the rightmost end of spool 2 passes solenoid 3 e and its accelerating force is diminished, current to solenoid 3 e is terminated (and current to solenoid 3 d is also terminated), and solenoid 3 f is energized to continue force on spool 2 through the entire acceleration zone. As the valve spool clears the acceleration zone, the opposing solenoids can be energized to create a reverse force on the valve spool, thereby decelerating the valve spool as it approaches the rest position. Thus, in this embodiment, if the current to the solenoids is reversible, the solenoids can be used both to accelerate and decelerate, thus dispensing with need for separate acceleration/deceleration means, e.g. springs. To reverse the movement of spool 2 from its rightmost position to its leftmost position, the reverse process is employed. Current to solenoid 3 f is terminated and solenoids 3 e and 3 d are energized. As the leftmost end of spool 2 passes solenoid 3 d , current to solenoids 3 d and 3 e is terminated, and solenoid 3 c is energized until spool 2 reaches its leftmost position.
Another modification would be to use means other than solenoids to provide the primary forces to accelerate the spool (or movable component in other embodiments). For example, FIG. 3 shows a third embodiment which utilizes hydraulic pressure to provide force for acceleration of spool 2 . Spool 2 is shown in its rightmost position. To accelerate spool 2 to the left, valve 23 opens high pressure line 24 to spool port 25 while disconnecting low pressure line 26 from spool port 25 . Valve 22 at the same time closes high pressure line 27 from spool port 28 while connecting low pressure line 27 to spool port 28 . The high pressure hydraulic fluid acts on the right end of the spool 2 , accelerating it to the left while fluid in the volume left of spool 2 flows from spool port 28 through valve 22 to low pressure line 29 . To accelerate spool 2 from its leftmost position to the right, the reverse process is employed.
In yet another modification the springs would be deleted to minimize the “hold” force required of the solenoids (especially for applications where the valve will be in either the on or off position for an extended time) and other means would be used to decelerate the spool, such as, “hydraulic stops”.
A fourth embodiment of the invention employs hydraulic force balancing on the spool to minimize the friction opposing movement of the spool. FIGS. 4A and 4B show one means of providing hydraulic balance for the valve described in FIG. 1 . In the off position, (FIG. 4A) fluid from the high pressure fluid supply port 4 acts on a bottom portion of the cylindrical surface of the spool 2 which increases the force of a top portion of the spool on the valve block 12 which increases friction when movement of the spool occurs, since the fluid discharge port 5 is likely to be at much lower pressure. By providing fluid at the same pressure as the fluid in the fluid supply port 4 to an area of the top portion of the spool that is equal to the area exposed to the bottom face of the spool through the fluid supply port 4 , hydraulic balancing results. Accordingly, a fluid passage 18 connects the fluid supply port 4 to spool flow passage 9 in the valve off position. Fluid at the high pressure within port 4 is thereby provided to balancing port 20 to provide hydraulic balance. As the spool accelerates, the spool flow passage 9 moves beyond balancing port 20 and pressure begins to dissipate in balancing port 20 because it no longer is in direct communication with fluid supply port 4 and some leakage inherently will occur. As the spool flow passage 9 enters flow passage 8 , high pressure fluid from fluid supply port 4 comes into direct communication with fluid discharge port 6 and hydraulic balance resumes. The surface area of spool 2 exposed to balancing port 20 is approximately equal to the surface area of spool 2 exposed to flow passage 8 on the side of inlet port 4 when the valve is in the off position shown in FIG. 4 A.
A fifth embodiment of the invention is shown in FIGS. 5A and 5B. The operation of this valve will be described as it could be applied to the control of fuel (i.e., fluid) injection directly into the cylinder of an internal combustion piston engine.
Fluid supply port 30 is supplied with high pressure fuel. Fuel discharge port 31 is connected to a pressure-actuated fuel injector (not shown). Fuel vent port 32 is connected to fuel discharge port 31 , or is connected to the line (not shown) connecting the fuel discharge port 31 to the fuel injector, or is connected directly to the fuel injector. Fuel return port 33 returns vented fuel to the fuel tank (not shown).
FIG. 5A shows the valve in the “off” position. When a command is given to inject fuel, solenoid 3 a is disengaged, and solenoid 3 b is engaged. Acceleration occurs as previously described in connection with FIG. 1 A. Spool flow passage 35 passes beyond valve block flow passage 38 as spool flow passage 36 begins to enter valve block flow passage 39 and fuel is quickly supplied to the injector through fuel discharge port 31 . Deceleration occurs as described in connection with FIG. 1 A. FIG. 5 B shows the spool 37 at rest in the valve “on” position. When a command is given to terminate the injection of fuel, solenoid 3 b is disengaged, and solenoid 3 a is engaged. As spool flow passage 36 passes beyond fuel valve block flow passage 39 , spool flow passage 35 enters valve block flow passage 38 , and the injector pressure is quickly vented, providing a clean, quick termination of the injection event.
A sixth embodiment of the invention is shown in FIGS. 6A and 6B. FIGS. 7A and 7B show, as a seventh embodiment, an acceleration/deceleration gas flow valve that includes a fast actuator 60 which would be controlled by the valve of FIGS. 6A and 6B.
FIG. 6A shows the control valve spool 48 in the position which will result in the gas flow valve of FIG. 7A being in the closed position. Considering FIGS. 6A and 7A together, high-pressure fluid is supplied to ports 41 and 42 . With the spool flow passage 49 providing fluid communication between port 42 and port 43 , and port 43 connected to port 61 of the fast actuator 60 , high-pressure fluid has acted on hydraulic piston 62 to move the poppet valve 63 against its seat 64 , formed in cylinder head 65 closing a combustion chamber formed in an engine block (not shown). With poppet valve 63 seated in seat 64 the flow of gas between gas ports 66 and port 67 formed in cylinder head 65 is blocked. In order for the hydraulic piston 62 to travel to its lowermost position as shown in FIG. 7A, hydraulic fluid on the bottom side of hydraulic piston 62 flows out port 68 and, with port 68 connected to port 47 , discharge fluid flows through spool flow passage 50 to port 46 which is connected to a low-pressure fluid storage tank (not shown).
When a command is given for the gas flow valve of FIG. 7A to open, solenoid 3 b is disengaged, solenoid 3 a is engaged, and the control valve spool 48 is first accelerated, and then decelerated to a stop in the position shown in FIG. 6B in the manner previously described in connection with FIG. 1 B. As spool flow passage 49 enters valve block flow passage 51 it comes into communication with high-pressure fluid supply port 41 , high-pressure fluid flows to port 40 and, with port 40 connected to port 69 , high-pressure fluid acts on the bottom side of hydraulic piston 62 which, with the assistance of energy-absorbing spring 70 , begins acceleration of poppet valve 63 . Poppet valve 63 reaches a high speed as it approaches gas ports 66 and thus provides rapid opening. With ports 68 and 61 unable to permit the flow of fluid through the control valve, fluid on the top side of the hydraulic piston 62 must flow from port 72 to port 44 through spool flow passage 50 to port 45 which, like port 46 , is connected to a low-pressure fluid storage tank (not shown). As the hydraulic piston 62 reaches energy absorbing spring 74 , poppet valve 63 has passed to a position above gas ports 66 , and deceleration can begin. As hydraulic piston 62 compresses energy absorbing spring 74 and begins to close port 72 , it rapidly decelerates until it stops at a position (FIG. 7B) where it has closed port 72 , and fluid can no longer flow. The poppet valve 63 acting in the manner of the acceleration/deceleration spool valve of FIGS. 1A and 1B, provides very fast initiation of gas flow during opening and very fast termination of gas flow during closing. The pressure/port arrangement described above for the acceleration/deceleration control valve of FIGS. 6A and 6B provides hydraulic balancing of the control valve.
The eighth embodiment shown in FIG. 8 is modification of the seventh embodiment wherein the poppet valve 63 shown in FIGS. 7A and 7B is replaced by a conventional poppet valve actuated hydraulically and controlled by the acceleration/deceleration valve of FIGS. 6A and 6B, in the same manner described for the valve of FIGS. 7A and 7B, but without the acceleration/deceleration features of the gas flow control valve of FIGS. 7A and 7B.
A ninth embodiment of the valve of the present invention is shown on FIG. 9A; and FIG. 9B shows how this valve could be used to create a unique fuel (or other fluid) injection system. The acceleration/deceleration control valve 80 shown in FIG. 9A is of the two-way cartridge type. High pressure fuel would be supplied to the supply port 81 . In its maximum down position, poppet valve 82 would remain seated against its seat 83 , preventing the flow of fuel. Spring 84 must be strong enough to hold poppet valve 82 in its maximum down position and must offset the force created by the high pressure fuel acting on the exposed face of poppet valve 82 at supply port 81 . When a command to open is given, solenoid 85 is engaged and acts on poppet valve piston 86 to accelerate poppet valve 82 in the upward direction. As poppet valve 82 begins to move, high pressure fuel flows in through supply port 81 and accesses the larger area of the bottom face 87 of poppet valve 82 . This additional force on valve 82 greatly increases its acceleration. As with the other embodiments of the acceleration/deceleration valve, a high speed is reached before the bottom face 87 of the poppet valve 82 crosses the exit ports 88 , located in the cartridge valve body 90 , thus providing a rapid opening of valve 80 . The valve block 92 then collects the fuel flow through exit ports 88 in flow passage 91 and allows fuel flow to continue through block port 93 . Poppet valve 82 begins deceleration after the bottom face 87 of the poppet valve 82 crosses the top of exit ports 88 , due to compression of spring 84 and the closing of vent ports 94 (as more fully described with reference to FIGS. 7A and 7B) by poppet valve 82 . Poppet valve 82 is held in its uppermost position by solenoid 85 and/or the force of the high pressure fuel on the exposed face of poppet valve 82 , and fuel flows to the injector. As will be described in greater detail with reference to FIG. 9B, when a command to stop fuel flow to the injector is given, the fuel pressure below the exposed face of poppet valve 82 is reduced, and solenoid 85 is disengaged. Spring 84 acting on poppet valve 82 then causes downward acceleration of poppet valve 82 , which first travels past and the closes exit ports 88 (and thus stops fuel flow) and then approaches seat 83 . As poppet valve 82 approaches its lowermost position, fuel flow past seat 83 is being restricted by poppet valve 82 thereby providing a hydraulic means for rapid deceleration to its lowermost position.
FIG. 9B shows a line 100 for supplying fuel at a high pressure from a supply source (not shown), two control valves 80 and 80 ′, as described in FIG. 9A, together with a pressure actuated fuel injector 95 and an orifice 97 , which in total are a unique fuel injection system. When a command to inject fuel is given, valve 80 ′ is opened very quickly in the manner described with reference to FIG. 9A, and fuel flows to injector 95 , providing a very rapid beginning of injection (a very highly desired characteristic in direct fuel injection systems). Because it is the objective of fuel injection systems to provide the maximum system pressure drop across the nozzle orifice(s) 96 so that the best possible fuel atomization can occur, orifice 97 must be sized so as to not represent a significant restriction to flow when fuel is to flow through orifice(s) 96 . When a command to terminate injection is given, the solenoid of valve 80 ′ is disengaged and the solenoid of valve 80 is engaged. As was described in reference to FIG. 9A, valve 80 opens very quickly and allows the high pressure fuel between orifice 97 and orifice(s) 96 to be vented through port 98 and returned to the fuel tank (not shown). Orifice 97 then restricts the flow of fuel because the flow passage of valve 80 has a much larger flow area than orifice 97 . This reduced line pressure: (1) causes very rapid and precisely controllable termination of flow across the injector orifice(s) 96 (very highly desired characteristics for direct fuel injection systems), and (2) allows valve 80 ′ to close quickly because of the reduced pressure on the face of poppet valve 82 , as described in reference to FIG. 9 A. As valve 80 ′ closes, the solenoid of valve 80 is disengaged so that valve 80 begins closing before fuel line pressure can be restored by flow through orifice 97 . Valve 80 will shut more slowly than valve 80 ′ because it will experience a relatively much higher pressure on the face of its poppet valve 82 than valve 80 ′ experiences. However, fuel injection has already terminated and a somewhat longer closing time for valve 80 has little undesirable consequence.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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A fast-acting valve includes a valve body and a spool slidably mounted within the valve body between first and second limit positions. Both the spool and the valve body have a flow passage which come into alignment with the valve spool at a position intermediate the first and second limit positions and spaced therefrom by a given distance. That given distance allows the spool member to accelerate in travel from the first and second limit positions to the valve open position so that the opening of the valve (and closing) occurs quite quickly. Reciprocating movement of the valve spool relative to the valve body can be provided by springs mounted in opposing ends of the valve body bore in cooperation with solenoids mounted on opposing sides of the valve body. The fast-acting valve may be modified into the form of poppet valve or a cartridge valve.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority from Korean Patent Application No. 10-2016-0045090, filed on Apr. 12, 2016, the disclosure of which is incorporated herein in its entirety by reference.
TECHNICAL FIELD
[0002] The present disclosure generally relates to the field of refrigerators, and more specifically, to lighting assemblies for refrigerators.
BACKGROUND
[0003] A refrigerator is an apparatus used for storing food at a low temperature and may be used to store food in a frozen state or a refrigerated state using separate compartments.
[0004] The interior of a refrigerator is typically cooled by a continuous supply of cold air. The cold air is generated by a refrigerant using a cycle consisting of compression, condensation, expansion and evaporation (e.g., a thermodynamic or “heat exchange” cycle). The cold air supplied to the refrigerator is provided to the interior of the refrigerator by convection and is used to store food at a desired temperature within the refrigerator.
[0005] Refrigerators may include a main body having a rectangular shape and an opening on a front surface thereof. A refrigeration chamber and a freezer chamber may be disposed within the main body. A refrigeration chamber door and a freezer chamber door are used for selectively opening and closing the open portions of the front surface of the main body. Drawers, shelves, storage compartments, and the like may be provided in the internal storage spaces of the refrigerator for optimally storing different types of food.
[0006] Top-mount refrigerators having a freezer chamber positioned at an upper end of the refrigerator and a refrigeration chamber positioned at a lower end of the refrigerator are a common type of refrigerator. In recent years, however, bottom-freeze refrigerators having a freezer chamber positioned at a lower end of the refrigerator have become popular due to enhanced user convenience.
[0007] For conventional refrigerators, even when the internal temperature and humidity of a produce compartment are kept constant, it may be difficult to maintain the freshness of produce (e.g., fruit, vegetables, herbs, etc.) stored in the produce compartment for a long period of time. The produce may quickly wilt or decompose while stored in this way. Thus, a demand exists for a method or device capable of storing produce in a produce compartment of a refrigerator to better preserve the freshness and/or improve the texture (e.g., “mouth-feel”) of the produce.
SUMMARY
[0008] Embodiments of the present disclosure provide a refrigerator and a lighting assembly for a refrigerator capable of storing produce in a fresh state within a produce compartment.
[0009] According to one embodiment, a refrigerator is disclosed. The refrigerator includes a refrigerator main body, a cold air generation unit disposed within the refrigerator main body and configured to generate cold air within the refrigerator main body, a produce storage unit disposed within the refrigerator main body configured to accommodate a removable produce box, and a lighting assembly configured to illuminate produce stored within the produce box. The lighting assembly includes a light emitting body including a light-emitting diode (LED) configured to irradiate the produce with LED light to preserve freshness of the produce, and a diffusion plate disposed on an inner wall of the produce box and configured to uniformly diffuse the LED light into an internal space of the produce box.
[0010] According to another embodiment, a refrigerator is disclosed. The refrigerator includes a refrigerator main body, a cold air generation unit configured to generate cold air within the refrigerator main body, a produce storage unit configured to accommodate a removable produce box, and a lighting assembly configured to illuminate produce stored within the produce box. The lighting assembly includes a light emitting body configured to irradiate the produce with light, a mounting bracket configured to mount the light emitting body to the produce storage unit, and a diffusion plate disposed on an inner wall of the produce box and configured to diffuse the light into the produce box. The mounting bracket includes a mounting plate disposed on a guide shelf of the produce storage unit and having a hole through which the light is transmitted, and a plurality of support pieces protruding from the mounting plate to support the light emitting body.
[0011] According to another embodiment, a lighting assembly for a refrigerator is disclosed. The lighting assembly includes a light emitting body configured to irradiate light, a mounting bracket disposed in a produce storage unit of the refrigerator, and coupled to the light emitting body, and a diffusion plate disposed on an inner wall of a removable produce box of the produce storage unit and configured to diffuse the light into the produce box.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a side sectional view illustrating an exemplary refrigerator according to one embodiment of the present disclosure.
[0013] FIG. 2 is a side sectional view illustrating an exemplary lighting assembly of a refrigerator according to one embodiment of the present disclosure.
[0014] FIG. 3 is a partially cutaway perspective view illustrating an exemplary lighting assembly of a refrigerator according to one embodiment of the present disclosure.
[0015] FIG. 4 is a perspective view illustrating a coupling state between an exemplary light emitting body and an exemplary mounting bracket of a refrigerator according to one embodiment of the present disclosure.
[0016] FIG. 5 is a partially cutaway perspective view illustrating an exemplary lighting assembly of a refrigerator according to one embodiment of the present disclosure.
[0017] FIG. 6 is a side sectional view illustrating an exemplary lighting assembly of a refrigerator according to embodiments of the present disclosure.
DETAILED DESCRIPTION
[0018] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here.
[0019] One or more exemplary embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which one or more exemplary embodiments of the disclosure can be easily determined by those skilled in the art. As those skilled in the art will realize, the described exemplary embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure, which is not limited to the exemplary embodiments described herein.
[0020] It is noted that the drawings are schematic and are not necessarily dimensionally illustrated. Relative sizes and proportions of parts in the drawings may be exaggerated or reduced in size, and a predetermined size is merely exemplary and not limiting. The same reference numerals designate the same structures, elements, or parts illustrated in two or more drawings in order to exhibit similar characteristics.
[0021] The exemplary embodiments of the present disclosure illustrate ideal exemplary embodiments of the present disclosure in more detail. As a result, various modifications of the drawings are expected. Accordingly, the exemplary embodiments are not limited to a specific form of the illustrated region, and for example, may include modifications in form due to manufacturing.
[0022] The configuration and operation according embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.
[0023] FIG. 1 is a side sectional view illustrating an exemplary refrigerator according to one embodiment of the present disclosure. FIG. 2 is a side sectional view illustrating an exemplary lighting assembly of a refrigerator according to one embodiment of the present disclosure. FIG. 3 is a partially cutaway perspective view illustrating an exemplary lighting assembly of a refrigerator according to one embodiment of the present disclosure. FIG. 4 is a perspective view illustrating a coupling state between an exemplary light emitting body and an exemplary mounting bracket of a refrigerator according to one embodiment of the present disclosure.
[0024] Referring to FIGS. 1 to 4 , according to one embodiment of the present disclosure, a refrigerator 60 is capable of uniformly irradiating LED light on produce contained in a produce box 50 to maintain the freshness of produce for a relatively long period of time. The refrigerator 60 is a top-mount-type refrigerator in which a freezer chamber 11 is positioned above a refrigeration chamber 12 . However, the present disclosure is not limited thereto and may be applicable to different types of refrigerators.
[0025] The refrigerator 60 may include a refrigerator main body 10 which forms an outer shell of the refrigerator 60 , a door configured to selectively open and close an internal space of the refrigerator main body 10 , a cold air generation unit 30 configured to generate cold air, a produce storage unit 40 configured to accommodate a produce box 50 , and a lighting assembly 100 configured to diffuse and supply LED light to produce stored in the produce box 50 .
[0026] Specifically, the refrigerator main body 10 may be divided into a freezer chamber 11 and a refrigeration chamber 12 by a barrier 13 . For example, the freezer chamber 11 may be provided in an upper portion of the refrigerator main body 10 . The refrigeration chamber 12 may be provided in a lower portion of the refrigerator main body 10 . The freezer chamber 11 and the refrigeration chamber 12 may be opened and closed using doors.
[0027] The doors (not shown) may include a freezer chamber door and a refrigeration chamber door. The freezer chamber door may seal the freezer chamber 11 by closing an upper front portion of the refrigerator main body 10 . The refrigeration chamber door may seal the refrigeration chamber 12 by closing a lower front portion of the refrigerator main body 10 .
[0028] The cold air generation unit 30 generates cold air for cooling the freezer chamber 11 and the refrigeration chamber 12 . For this purpose, the cold air generation unit 30 may include one or more freezing cycle devices for generating cold air. The freezing cycle devices may include, for example, a compressor, a condenser, an expansion valve and an evaporator, which together may be used to provide a freezing cycle. A heat exchange process using a refrigerant may be performed by implementing a freezing cycle consisting of compression, condensation, expansion and evaporation using the compressor, the condenser, the expansion valve and the evaporator, respectively. The air within the refrigerator 60 may be cooled by exchanging heat with the refrigerant.
[0029] The produce storage unit 40 may include a guide shelf 41 installed in the refrigerator main body 10 at a lower portion of the refrigeration chamber 12 , and an accommodation space, where the produce box 50 can be positioned within the accommodation space while being covered by the guide shelf 41 .
[0030] According to some embodiments, the bottom surface of the accommodation space includes a slanted surface 42 a inclined downward in the direction that the produce box 50 is inserted (e.g., slanted down toward the back side of the refrigerator). In this way, a user can insert the produce box 50 into the accommodation space of the produce storage unit 40 with a relatively small amount of force. For example, when a user inserts the produce box 50 into the accommodation space of the produce storage unit 40 , the weight of the produce box 50 is added to the user's pushing force. This enables a user to quickly and easily insert the produce box 50 into the accommodation space using a relatively small amount of force.
[0031] The lighting assembly 100 may include a light emitting body 110 , a mounting bracket 120 and a diffusion plate 130 . The lighting assembly 100 may diffuse and provide light to produce stored within the produce box 50 .
[0032] The light emitting body 110 may include an LED illuminator for irradiating produce with LED light. The LED illuminator may adjust the wavelength of LED light emitted to optimally maintain the freshness of produce.
[0033] For example, substantially red LED light emitted by the light emitting body 110 is capable of promoting the growth of produce. Substantially blue LED light emitted by the light emitting body 110 is capable of hardening the tissue of produce, thereby giving a crisp texture or “mouth feel” to produce. The produce irradiated by LED light in this way may have a fresh and crisp taste compared to produce irradiated by typical illumination light, or compared to produce not irradiated by light.
[0034] The light emitting body 110 may include different kinds of illuminators capable of generating light used to enhance the freshness of produce stored within the produce box 50 .
[0035] The mounting bracket 120 may be provided in the produce storage unit 40 for mounting the light emitting body 110 . For example, the mounting bracket 120 may include a mounting plate 121 installed on the guide shelf 41 of the produce storage unit 40 and a plurality of support pieces 122 protruding from the mounting plate 121 to support the light emitting body 110 (e.g., to support an edge of the light emitting body 110 ).
[0036] In the present embodiment, the mounting plate 121 is disposed at the rear side of the guide shelf 41 . The mounting plate 121 includes a through-hole 121 a through which light is transmitted. According to some embodiments, the support pieces 122 include four support pieces having an L-shaped cross-section for supporting the light emitting body 110 . However, the installation position of the mounting plate 121 , the shape of the through-hole 121 a and the number and shape of the support pieces 122 are not limited to those specified.
[0037] The diffusion plate 130 uniformly diffuses LED light into the produce box 50 . The diffusion plate 130 may be positioned on an inner wall of the produce box 50 , for example, on the inner wall of the produce box 50 below the light emitting body 110 .
[0038] According to some embodiments, the diffusion plate 130 may be mounted to a case (not shown) positioned along the inner wall of the produce box 50 , where the case may be formed using a dual injection method. For example, the diffusion plate 130 may be easily and stably mounted to the case of the inner wall of the produce box 50 using screws or a snap-fit method.
[0039] The diffusion plate 130 includes material capable of effectively diffusing LED light. For example, according to some embodiments, the diffusion plate 130 includes highly reflective aluminum. The diffusion plate 130 may uniformly diffuse the LED light irradiated from the light emitting body 110 and direct the LED light toward the produce. Thus, the produce stored within the produce box 50 may be uniformly irradiated by the LED light regardless of where the light emitting body 110 is positioned to thereby maintain optimal freshness of the produce.
[0040] FIG. 5 is a partially cutaway perspective view illustrating an exemplary lighting assembly 100 ′ of a refrigerator according to embodiments of the present disclosure.
[0041] As shown in FIG. 5 , the lighting assembly 100 ′ includes a diffusion plate 130 ′, which may be disposed on an inner wall of the produce box 50 and may have a surface which is curved (e.g., a convex shape). In this case, the curved surface may have a curvature such that the curved surface can receive LED light from the light emitting body 110 and can diffuse the LED light into the internal space of the produce box 50 .
[0042] The diffusion plate 130 ′ having a convex shape directed at the internal space of the produce box 50 can effectively diffuse and reflect the light of the light emitting body 110 toward produce stored in the produce box 50 .
[0043] FIG. 6 is a side sectional view illustrating an exemplary lighting assembly 100 ″ of a refrigerator according to embodiments of the present disclosure. As shown in FIG. 6 , the lighting assembly 100 ″ includes a diffusion plate 103 ″, which may include a first reflection plate 131 mounted to a rear inner wall of the produce box 50 below the light emitting body 110 , and a second reflection plate 132 mounted to a front inner wall of the produce box 50 .
[0044] The first reflection plate 131 is obliquely positioned at a predetermined angle on the rear inner wall of the produce box 50 to face the front upper side of the produce box 50 . The first reflection plate 131 reflects the LED light received from the light emitting body 110 toward the front upper side of the produce box 50 . The second reflection plate 132 is obliquely positioned at a predetermined angle on the front inner wall of the produce box 50 to face the rear lower side of the produce box 50 . The second reflection plate 132 reflects the LED light received from the first reflection plate 131 toward the rear lower side of the produce box 50 .
[0045] Accordingly, if the light emitting body 110 is installed at the rear of the produce box 50 , part of the LED light of the light emitting body 110 may directly irradiate the produce positioned at a rear portion of the produce box 50 . The remainder of the LED light may be reflected by the first reflection plate 131 toward the second reflection plate 132 , and the LED light irradiates the produce positioned at a front portion of the produce box 50 .
[0046] As a result, the produce stored within the produce box 50 may be uniformly irradiated by the LED light from the light emitting body 110 and the diffusion plate 130 ″, and the produce may be kept in an optimally fresh state.
[0047] As described above, according to the present disclosure, it is possible to uniformly diffuse and irradiate LED light on the produce stored within the produce box. This makes it possible to maintain the produce stored within the produce box in an optimally fresh state for a long period of time and/or to improve the texture of the produce (e.g., mouth feel).
[0048] Although exemplary embodiments of the present disclosure are described with reference to the accompanying drawings, those skilled in the art will understand that the present disclosure may be implemented in various ways without changing the necessary features or the spirit of the present disclosure.
[0049] Therefore, it should be understood that the exemplary embodiments described above are not limiting, but only an example in all respects. The scope of the present disclosure is expressed by claims below, not the detailed description, and it should be construed that all changes and modifications achieved from the meanings and scope of claims and equivalent concepts are included in the scope of the present disclosure.
[0050] From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. The exemplary embodiments disclosed in the specification of the present disclosure do not limit the present disclosure. The scope of the present disclosure will be interpreted by the claims below, and it will be construed that all techniques within the scope equivalent thereto belong to the scope of the present disclosure.
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A demand exists for a method or device capable of improving the length that produce can be kept fresh within a produce compartment of a refrigerator. The present disclosure provides a refrigerator including a cold air generation unit configured to generate cold air required within the refrigerator main body, a produce storage unit configured to accommodate a produce box, and a lighting assembly configured to illuminate produce stored within the produce box. The lighting assembly includes a light emitting body including an LED illuminator configured to irradiate LED light for enhancing the freshness of the produce. A diffusion plate disposed on an inner wall of the produce box is used to diffuse the light into the produce box.
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BACKGROUND
The invention concerns a yarn texturing nozzle having a compression section. A nozzle of this kind is described for example in the German patent application DE 20 36 856. The yarn entering from above into the nozzle is conveyed by a hot-air stream to a compression section which is provided with openings that are for example of slot shape. By lateral escape of the injected air, a compression of the endless fibre and thus also a deceleration occurs due to the rate of speed reduction within the passage channel. The thereby formed yarn plug is relatively slowly discharged from the nozzle and is thereby cooled down. A rotary cooling drum can be used, on whose surface the compressed yarn is laid and whereby through perforations in the drum air of lower temperature than in the nozzle prevails, e.g. room air, for the cooling of the yarn.
The invention relates to the compression section of a texturing nozzle, in particular to a BCF texturing nozzle, for high speeds. The compression section of a texturing nozzle is conventionally made up of an upper lamellar holder, an end piece and a number of lamellar. In a modified exemplified embodiment, the compression section can also be a tube type piece, which over a section of its length is being provided with a number of longitudinal slots.
The texturing air and the yarn enter the compression section from above at high speed, that is in the flow direction of the fibres or the air respectively. In the area of the compression section, the air flows more or less radially all of a sudden through the slots or the gaps respectively between the lamellar and to a large extent discharges outward to the outside of the lamellar. This causes a reduction of the air speed within the longitudinal channel of the nozzle. Thus the yarn is decelerated and forms a plug which fills the whole diameter of the slotted part, that is the compression section. The plug then slides further downwards through a plug guide tube and further on to a cooling drum or to a conveying device, in particular a pair of rollers. It cannot be prevented that at this position at which the air leaves the slot, single fibrils can be loosened from the yarn and be pulled more or less far outward radially into the slots. Loops can also leave the slots extending beyond the outer edges of the lamellar, thereby said loops can get mutually entangled with loops extending from the neighboring slots. Since the loops or fibres between the slots exiting laterally from the actual yarn or plug guide tube respectively, move downwards together with the plug, they hit the end piece, or in the case of another exemplified embodiment hit an edge or pocket respectively, forming the end of the slot. Thus single loops may remain hooked and thus be pulled far out from the plug or even get torn off. In practice, said protruding loops or filament parts in the finished yarn are known as “pullers” (Zupfers), which can cause difficulties during further processing.
SUMMARY
The improved compression section consists of a tube type piece with slots in the longitudinal direction. According to the invention, these slots are completely open at their lower ends and the lamellar formed by these slots area only connected with each other at the upper end, or they are connected to each other at a distance from the lower end in circumferential direction and in opposite direction to the nozzle. In other words, the lamellar are fastened at the air or the yarn entering point respectively, or close to it at the compression section or the lamellar holder respectively. They can also be fastened to a flange, which again is screwed onto a conveying means at the inlet side of the texturing nozzle or which is fastened with other fastening means. In the outflow direction of the air or in conveying direction of the plug respectively, the lamellar are without contact to parts surrounding the nozzle, in particular without contact to an end piece or a guiding part for the plug succeeding the compression section. The plug guide tube following the compression section, i.e. the portion opposite the free ends of the lamellar, forms, together with the lower end of the compression section, a narrow gap, in particular a truncated cone shaped gap.
Since the ends of the lamellar are free in the downward direction and without contact to the surrounding parts of the nozzle, the filament loops exiting the slots or gaps respectively between the lamellar have no chance to entangle or to remain hooked, whereat the formation of pullers (Zupfer) or broken fibrils is suppressed or considerably reduced respectively. If the fibrils exiting between the lamellar hit the truncated cone-shaped inlet part of the guiding part or end piece respectively, then they come to lay on a smooth surface without niches and edges, and therefore, the risk of pulling-out from the plug does practically not exist anymore. Thus, with the suggested configuration of the compression section the running reliability of the texturing nozzle is considerably increased.
The compression section according to the invention can be used for all types of nozzles by which a yarn plug is formed, that is for instance also for the type of a plug formation through friction within the compression section, or with nozzles by which the plug formation is controlled by a cooling drum succeeding the texturing nozzle, or with nozzles, which are succeeded by a pair of rollers for controlling the plug formation.
As mentioned, it is an object of the invention to increase the operating reliability of a nozzle, in that a compact plug is being formed without fibrils projecting out from said plug. Additional object and advantages of the invention will be set forth.
The texturing device according to the invention is characterized by a nozzle with an inlet part, a conveying part, a compression section and a guiding part, whereat between the inlet part and the conveying part hot air or steam is let into a yarn guiding channel, which can exit within the zone of the compression section, whereat the lamellar at the outlet side of the compression section are free towards the surrounding, in particular without contact to the parts surrounding the nozzle and/or to a succeeding guiding part. In the conveying direction, a conveying part is arranged in front of the compression section and behind the compression section lays a guiding part or plug guide tube. On the inlet side of the compression section the lamellar are held by a lamellar holder, whereat the inlet side is neighboring a conveying part next to the nozzle inlet. The lamellar at the end opposing the inlet side of the nozzle freely project without support in the downward direction. The outer contour of the lamellar is either parallel to the conveying direction of the air or the textile fibres respectively, or is at a slant angle to it. In particular, at the outlet side the lamellar are slanted on their outside. Since the lamellar are arranged circularly, their outer contours around a conveying channel for a yarn plug, which lays inside the compression section, describe a contour in the form of a truncated cone-shaped shell surface. Accordingly, the succeeding guiding part or plug guide tube respectively, following the compression section is provided in the form of a truncated cone-shaped inlet funnel of the following guiding part, a gap, a ring shaped gap in particular, which preferably is of the shape of a truncated cone shall. The nozzle is to be applied as texturing nozzle for filament yarns. Following the nozzle a conveying means if arranged, for instance a pair of rollers or a drum, to convey the textured yarn or the plug respectively, the latter being furnished with a channel to guide the yarn plug.
Within a texturing device, in particular at a maximum length of the compression section of 60 mm, a guiding part at maximum of the same length follows, in which the texturized yarn in the form of a plug can be led to the surface of the drum, and then following this first guiding part, after a deviation, a second guiding part alongside the surface of the drum is provided, in that on one hand the texturized yarn is led in the radial and on the other hand in the axial direction of the drum.
The invention is being described in the following by way of the drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic cross section of a texturing nozzle with a succeeding cooling drum from the German application DE 199 55 227.4,
FIG. 2 a cross section through a texturing nozzle according to the invention in a schematic illustration, and
FIG. 3 an overview of a texturing nozzle with succeeding rollers or drums respectively.
DETAILED DESCRIPTION
Reference will now be made in detail to embodiments of the invention, examples of which are shown in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features of one embodiment may be combined with those of another embodiment to yield still a further embodiment. It is intended that the invention include these and other modifications and variations.
The nozzle is shown in FIG. 1 together with a cooling drum 22 . The yarn entering from above is led by an inlet part 12 down to the point at which hot air or overheated steam is fed through channels directed slantwise downwards - there can be one or several such channels. Said air together with the yarn flows through the succeeding conveying part 14 down to the inlet of the compression section 16 . The compression section is preferably formed by lengthwise lamellar being arranged around the yarn or by slots, through which the hot air can leave radially outward. Within the compression section the so called plug is formed, which maintains its shape and its density within a succeeding first guiding part 18 and a second guiding part 20 . Contrary to the state of the know art, the yarn plug is moved onward in such a way that it cannot expand itself. In the transition zone between the first guiding part 18 and the second guiding part 20 the yarn is deviated basically at a right angle, according to the figure in a downward direction. The second guiding part extends further over a certain length along the circumference of the rotating, perforated drum 22 , on which surface the texturized yarn is guided within a channel 24 . Inside the drum a sub-pressure condition is maintained so that cooling air can enter via the plug running along the surface of the drum 22 and through the perforation. By narrow guidance, the plug is hindered from making relative movement with regard to the drum. This is accomplished on one hand by way of the lateral channel walls and on the other hand by the air escaping in concentrated manner at the bottom of the channel. The plug is thus led over a circular path on the circumference of the drum 22 and maintains its form and density until the yarn is taken off the drum 22 by means of a not further shown conveying means. Only at this stage does a so called expansion of the plug take place.
Essential features of the nozzle 10 according to the invention in cooperation with a drum 22 are based on the face, that the yarn plug after leaving the compression section 16 is hindered from expanding. This is in particular achieved by the deviation between the first guiding part 18 and the second guiding part 20 as well as by way of the narrow guidance within these zones, for instance, between the second guiding part 20 and a channel 24 within the perforated drum 22 . With conventional nozzles where the texturized yarn is freely placed onto the surface of the cooling drum, the yarn plug can form loops due to the lack of lateral guidance, whereat partial expansion of the plug occurs. Due to the free exit of the yarn plug at the outlet of the nozzle according to the state of the art as mentioned at the beginning, a stronger deceleration, also within the zone of the plug formation through friction, also within the compression section 16 , is required, in order to achieve the necessary crimping effect. This can lead to problems, when changing operating conditions, which have an influence on the friction value.
In that the plug is being hindered from changing its shape within the guiding part 18 or 20 respectively, following the compression section 16 , the texturing of the yarn within this part of the nozzle is better stabilized than in convention nozzles.
According to FIG. 2 the nozzle 10 is also divided into a conveying part 14 , a compression section 16 and a guiding part 18 , whereby the latter is also called plug guide tube. Into the conveying part 14 air enters into a conveying channel from the side, as is indicated by arrows shown at the top, through which conveying channel the yarn to be texturized is guided downwards. According to the exemplified embodiment, the compression section consists of a lamellar holder 26 on which at the lower end the lamellar 28 are arranged. Numerous lamellar are arranged circumferentially, so that between the lamellar slots or gaps respectively, are formed, through which, within the zone of the compression section 16 , the air exits more or less radially in direction of the arrow at 28 through the slots between the lamellar. The lamellar holder 26 can be made as a flange, which either is made as a one-piece part with the lamellar 28 , or the lamellar holder can carry the lamellar 28 which are inserted into the lamellar holder and which for instance are connected to it by soldering. The outer contour 28 of the lamellar can, as indicated with full lines, run slantwise to the flow direction of the air or conveying direction of the yarn respectively, or the outer contour of the lamellar is, as indicated by dotted lines, basically parallel with the flowing direction and converges at least towards the outlet side end of the plug slantwise to the conveying direction, so that at the outlet side the outer edges of the lamellar basically form the shape of a truncated cone, which truncated cone protrudes into an end piece 18 or the guiding part respectively or the plug guide tube 18 , whereat the end piece 18 or the guiding part 18 respectively are also being provided with a truncated cone-shaped surface. The outlet side of the lamellar 28 and the inlet side of the end piece 18 or the guiding part 18 respectively, preferably are formed in such a way that between the outer contour 28 of the lamellar 28 and the inner surface of the end piece 18 or the guiding part 18 respectively a narrow gap of approximately constant height is formed. This gap also has the shape of a truncated cone shell.
Generally speaking, the angle between a first reference line a at the outlet contour 28 of a lamellar 28 and a second reference line b extending from the shell line of the truncated cone forming the inlet side of the guiding part 18 , can form a first angle, while the second reference line b together with an edge 10 a of the nozzle 10 includes an angle b. Preferably the following ranges are suggested for the angles a and b:
a=0 . . . 1 . . . 4°
b=30 . . . 45 . . . 60°
whereat the underlined values have proved preferable in practice. Between the end part 18 and the first guiding part 18 a parting plane 18 can lay.
With FIG. 3 again is shown schematically that in succession of a nozzle 10 either a pair of rollers 22 for drawing off the formed yarn plug can be provided, or a single drum 22 over whose outer surface the plug is drawn off in a controlled manner, as is described in the German patent application DE 199 55 227.4. The latter application is to be considered an integrated part of the present application.
It should be apparent to those skilled in the art that modifications and variations can be made to the embodiments of the invention described herein without departing from the scope and spirit of the invention as set forth in the appended claims.
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A nozzle for the treatment of threads is divided in the conveying direction into a conveying part, a compression section and a guiding part. The compression section, for the purpose of forming a yarn plug, includes fixedly arranged radially and axially directed lamellar. The ends of the lamellar which face the guiding part are neither in contact with each other nor with any surrounding parts of the nozzle so that fibers which are located in the gaps between the lamellar, and which radially exit the channel being formed by the lamellar can reach an inlet funnel of the guiding part or a plug guide tube respectively, without colliding with any edges.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/998,213, filed on Oct. 11, 2013, the entire contents of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to nock constructions for use with crossbows and more particularly to a vibration damping insert for reinforced nocks to absorb bow string slap.
BACKGROUND OF THE INVENTION
[0003] As shown in U.S. Patent Application Nos. 61/748,526 filed Jan. 3, 2013; 61/621,221 filed Apr. 6, 2012; and Ser. No. 13/785,862 filed Mar. 5, 2013; nocks usable with crossbows have been reinforced utilizing a metal support structure which surrounds a portion of a nock and a portion of the crossbow bolt to attempt to prevent fracture of the nock when the bolt is fired from the crossbow. It is noted that all of these patent applications are incorporated in their entirety by reference.
[0004] Whether the crossbow nock is lighted or unlighted in general crossbows have a significant safety problem in that crossbows are designed such that the string has some slight separation from the projectile prior to firing of the projectile upon release of the bow string. From a physics perspective the string travels forward and actually impacts or slaps the nock rather than pushing on the nock.
[0005] Nocks in general are plastic and existing plastic nock systems are problematic if the nock breaks. This can result in what is called a dry fire with the string moving forward without pushing on the projectile because the nock has broken or fractured. The result is that the string slides over the projectile. When this happens there is nothing to absorb all of the stored energy. Thus when the string is released all of the energy reverberates back into the bow which can cause damage to the bow itself.
[0006] As will be appreciated, in a dry fire situation in which the nock is fractured the energy is not put into the projectile but rather is put back into the bow where it can actually cause portions of the bow to break and detach, becoming a serious safety problem for the hunter or archer.
[0007] Metal nocks are known in the industry, although not used as commonly as plastic nocks. However, the metal nocks are solid and have no ability to be lighted. Lighting of nocks has proven to be a valuable means for the hunter or archer to easily track the trajectory of the projectile to correct shooting errors, and to locate the projectile after shooting. Additionally, the solid metal nocks do not have the ability to reduce the impact from the bow string, and can therefore cause unwanted vibration in the crossbow.
[0008] As a result and for crossbows in particular there is a significant need to be able to provide a plastic nock that is reinforced with either metal, a ceramic or an advanced composite that has the structural strength and ability to absorb the impact of the bow string. As mentioned above there are metal support structures that cooperate with the plastic nocks that to a certain extent limit the fracture or damage of the nock during crossbow firing. It will be appreciated that the amount of stress produced in the nock from the energy in the crossbow is over 7,000 psi.
[0009] Should the nock break or fracture not only is the bow string released with no retarding force such as would be associated with the bolt or projectile, the arrow itself can fly off at any angle thus potentially causing injury to the hunter or those nearby.
[0010] It is therefore important to be able to provide a nock structure capable of withstanding tremendous forces associated with the release of a crossbow string, the need being both for unlighted nocks and lighted nocks alike.
[0011] It will be appreciated that lighted nocks are activated when the bow string presses on a plunger which in turn presses on an internal light emitting diode assembly to close a switch between the light emitting diode and a battery pack contained within the bolt or arrow shaft. When the bow string is released the plunger is pushed in and the internal light is activated to provide a lighted nock that is used by the hunter to trace the path of the arrow and also to be able to find the arrow if it has missed its target. This in turn permits retrieval of the arrow for a missed shot.
[0012] In the case of lighted nocks a clear plastic is utilized for the nock construction so that light that is generated internal to the bolt or arrow shaft is radiated out from the lighted nock. It is therefore important to provide a lighted nock which is capable of sustaining the tremendous forces associated with the release of a crossbow bow string.
[0013] Not only is a fracture resistant nock important for lighted nocks it is likewise important for unlighted nocks. In addition to the reasons stated above, it is beneficial to have a shock absorbing elastomeric material as part of the construction of any nock, lighted or unlighted, to reduce vibration in the crossbow and bolt.
SUMMARY OF INVENTION
[0014] In order to prevent fracture of a nock, lighted or not, in the subject invention the distal portion of the nock is provided with a shock absorber insert that in essence absorbs the impact forces so that the nock will not shatter due to the slap of the bow string against the nock. An additional benefit of the system is the overall reduction in vibration in the system which tends to increase accuracy, reduce noise and improve overall shooting enjoyment from a smoother feel to the shooter.
[0015] In a preferred embodiment the nock is encased in the aforementioned metal support structure. However the distal end of the nock is provided with the shock absorbing material, in one case TPU or thermopolymer urethane or thermoplastic urethane as it is sometimes called. In one embodiment, the TPU shock absorber is injection molded into an aluminum housing and absorbs the impact to prevent the nock from breaking or shattering during firing, especially when there is a space between the bow string and the distal end of the nock causing a high impact slap against the nock that otherwise might cause the nock to fracture.
[0016] The preferred material for the shock absorber at the distal end of the nock is clear TPU. From a structural perspective the TPU allows some resilience and therefore vibration damping. As a result the slap from the string will be damped. It is noted that urethane has extremely good impact absorption characteristics, and is a material commonly used for skate wheels. It also has good absorption resistance as well as good impact absorption characteristics. Since the TPU is preferably clear, it allows a lighted nock to not only have the structural benefits from this insert but will also allow a light from a light assembly to exit to the rear of the bolt or arrow shaft when a battery and LED assembly is located at the proximal portion of the TPU insert.
[0017] Moreover, when the TPU insert is impacted by the bow string it moves slightly forward in the structural housing such that rather than having to utilize a plunger or pin to push the LED light emitting unit forward to make switch contact, the TPU insert itself forms a plunger like function that moves upon impact to push the end of a dome-shaped LED forward in the bolt or arrow shaft, whereupon traditional switch contact is made to illuminate the LED.
[0018] It is preferable to use injection moldable urethane as opposed to a castable urethane or a two part urethane. This is important because injection moldable TPU urethanes are stronger and more impact resistant than castable urethanes. Note first and foremost TPU must have the requisite strength. Secondly, it must have resilience or ability to absorb energy without permanent deformation. Thirdly, it must have good spring back characteristics after it has been pushed out of its shape so that it will spring back to its original shape without permanent deformation. Fourthly, it must have good vibration damping and have the requisite toughness as well as abrasion resistance. The above characteristics are best embodied in the TPU material which allows one to build the insert as a mechanical button comprising a molded piece of clear urethane. As the string moves forward it pushes the clear TPU forward to close a switch in the lighted nock assembly.
[0019] Note that there are a few alternate materials to TPU, but if so, they must be optically as clear as possible and must transmit a large portion of the light out the distal end of the nock. Other exemplary materials that could be used would be commonly referred to as thermoplastic elastomers (TPEs) or simply rubber materials. While rubber could not be used in a lighted nock, it would be sufficient in an unlighted application.
[0020] The TPU insert in the distal end of the nock may either have a notch or half-moon configuration to control the string motion appropriately to keep it from slipping off the back of the projectile. In another embodiment the TPU insert may be a flat disk button which is contacted by the bow string.
[0021] In summary, a shock absorbing insert is placed at the distal end of a nock, lighted or not, in which the insert serves as a shock absorber to prevent fracture or damage to the nock during crossbow firing, thus to eliminate safety problems associated with crossbow string slap. An additional benefit is the overall reduction in vibration throughout the crossbow and projectile system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other features of the subject invention will be better understood in connection with the Detailed Description, in conjunction with the Drawings, of which:
[0023] FIG. 1 is a diagrammatic illustration of a crossbow showing the separation between the bow string and the end of a typical nock at the distal end of a bolt, also showing the result of fracturing the nock during firing causing the bow string to be unloaded, also causing the arrow to move out of the crossbow chamber in an uncontrolled fashion;
[0024] FIG. 2 is a diagrammatic illustration showing the spacing of a crossbow bow string from the distal end of the nock, showing the spacing over which bow string slap is operative;
[0025] FIG. 3 is a diagrammatic illustration of a dry fire situation in which the unloaded bow string moves in a forward direction, causing the arms of the crossbow to snap or otherwise be damaged;
[0026] FIG. 4 is a diagrammatic illustration of the TPU shock absorber insert into a metal support structure which shows the motion of the TPU insert forward against an illumination source connected to a battery within the bolt or arrow shaft to activate the illumination source for providing an illuminated nock while at the same time absorbing the high loads due to bow string slap during crossbow operation;
[0027] FIG. 5 is a diagrammatic illustration of a typical compound crossbow arrangement showing the mechanical advantage cams;
[0028] FIG. 6 is a diagrammatic illustration of one embodiment of the subject shock absorber which is impacted by the bow string, with the shock absorber shown as an insert to a metal retaining cylinder at the distal end of a crossbow bolt;
[0029] FIG. 7 is a diagrammatic illustration of the force imparted to the TPU insert of the nock in FIG. 6 illustrating the force concentration against the distal end of the insert followed by a focusing of the force to the center of the insert;
[0030] FIG. 8 is a diagrammatic illustration of the insert of FIG. 7 showing the movement of the proximal end of the insert so as to activate an internal lighting structure;
[0031] FIG. 9 is a detailed diagrammatic illustration of the resilient shock absorber insert into a metal reinforcing structure showing the resilient shock absorber at the distal end of the nock;
[0032] FIG. 10 is a diagrammatic illustration of one embodiment of the resilient shock absorber illustrating a bow string notch and a central protruding rib adapted to be contacted by the crossbow bow string;
[0033] FIG. 11 is a further detailed diagrammatic illustration of the TPU resilient material insert surrounded by a metal reinforcing structure; and
[0034] FIG. 12 is a diagrammatic illustration of the resilient injection molded insert to be inserted into the metal support structure of FIG. 11 .
DETAILED DESCRIPTION
[0035] Referring now to FIG. 1 , a simplified crossbow 10 is provided with limbs 14 having a bow string 16 attached to the distal ends 18 of the limbs 14 . A bolt 20 is inserted into the breach 22 of the crossbow 10 in which bolt 20 has a nock 24 generally made of plastic which is adapted to be struck by bow string 16 when bow string 16 is released by trigger mechanism 26 , thus to project the bolt 20 forward upon bow string 16 release.
[0036] The problem with such a nock construction is that the nock may fracture as illustrated at 30 with the slap of bow string 16 against the distal end of the nock 30 . Not only does the fracturing of the nock 30 eliminate all loading on the bow string 16 as it is released which can cause fracture it also can cause the bolt shown at 20 ′ to move off axis as illustrated by arrow 32 which can impact hunters or other people nearby, a clear safety problem.
[0037] Referring to FIG. 2 , the problem with crossbows is that there is often a small but significant offset distance indicated by arrow 34 from the distal end 36 of nock 24 such that upon release of the bow string 16 , the bow string 16 rather than pushing against the nock 24 impacts the nock 24 in a slapping motion causing tremendous forces to be imparted to the nock 24 which can cause nock failure and even dry fire.
[0038] Referring to FIG. 3 , the dry fire situation is indicated in which a fractured nock 30 no longer provides a load on bow string 16 such that arms 14 of the crossbow may fracture as illustrated at 38 , again resulting in projectiles 20 ′ directed back at the hunter or archer or to individuals who may be in the immediate vicinity of the hunter.
[0039] Referring now to FIG. 4 , in one embodiment a cylindrical nock support structure 40 is utilized to house a shock absorbing insert 42 . Shock absorbing insert 42 in one embodiment is an injected moldable urethane in the form of a thermopolymer urethane or a thermoplastic urethane. Upon slap of the bow string a force 44 is imparted to the distal end 46 of the insert 42 which causes the insert 42 to slightly deform as well as move as illustrated by arrow 48 in the direction of a light assembly 50 causing the light assembly 50 to move in the direction of arrow 52 for activating a switch utilized to power the light assembly 50 .
[0040] It has been found that injection molded TPU is not permanently deformable but rather has a memory such that after impact of the bow string it moves back to its original position, in one embodiment having actuated an internally carried light source. Further it is noted that support structure 40 which in one case is metal and preferably aluminum is inserted into a channel 54 in the distal end of a bolt here shown at 56 such that a unitary structure is provided with the metal support structure 40 being inserted into channel 54 and extending aft to receive the injection molded TPU shock absorbing insert 42 .
[0041] Typically a crossbow 10 shown in FIG. 5 incorporates the mechanical advantage of a compound bow structure 60 to deliver a stress in the nock from the impact in excess of 7000 psi to the distal end of the bolt. This compound bow bowstring structure is generally indicated at 62 and is not described further other than to say that the amount of energy deliverable by the bow string 62 of such an assembly 60 is more than that necessary to fracture the traditional nock at the end of a bolt.
[0042] Referring now to FIG. 6 , what is shown is a shock absorber 70 inserted into a cylindrical metal support structure 72 which is in turn inserted into a channel 74 in the bolt, with the bow string 76 adapted to contact an internal bow string receiving structure 78 to propel the bolt as a projectile in a forward direction when the bow string 76 is released.
[0043] As illustrated in FIG. 7 , the injection molded portion 70 is shown having a cylindrical forward structure 80 which has projections 82 utilized to join this insert 70 to the metalized support structure 72 of FIG. 6 by insertion into orifices 73 in the support structure 72 .
[0044] As illustrated, the force imparted by the slap of the bow string is illustrated at 84 in terms of the arrows which impact first a transverse rib 86 which forms part of the shock absorber insert 70 , with the force then tending towards the center of the insert 70 as illustrated by arrows 88 .
[0045] Referring to FIG. 8 , the interior of the insert moves as illustrated by double ended arrow 90 to act as a shock absorber as well as in one embodiment to activate an internally carried nock light assembly. In FIG. 9 it can be seen that insert 70 is housed within metal support 72 such that it is able to move within this housing to provide the shock absorbing characteristics due to a flexible narrowed portion 75 . Thus the shock absorbing insert 70 is surrounded by a metal support structure 72 to increase the structural rigidity and strength of the crossbow bolt nock.
[0046] Referring to FIG. 9 , a more detailed view of the insert and nock structure is shown in which shock absorber 70 is shown carried by a metal support 72 which is inserted into a channel in bolt 20 , whereas in FIG. 10 the resilient shock absorber 70 is shown having an overall nock structure shown by notch 96 which has internal to the notch a transverse rib 78 adapted to be struck by the bow string.
[0047] Referring to FIG. 11 , the assembled structure with the resilient shock absorber insert and the metal support 72 is illustrated in which, as illustrated in FIG. 12 , the resilient shock absorber insert 70 to be placed into a metal structure 72 has the aforementioned projections 82 , which are adapted to lock into metal support 72 .
[0048] While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications or additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.
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A vibration damping nock for crossbow arrows includes an insert to absorb bow string slap, thereby to prevent damage to the nock during crossbow firing.
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BACKGROUND OF THE INVENTION
This invention relates to a guard post and more particularly to a guard post that is used on a loading dock of a warehouse or other building where material is handled primarily through the utilization of fork lifts and other loading equipment.
In the prior art it has been customary to anchor a cylindrical post directly into the foor, which is usually concrete, of a warehouse and then fill the cylindrical post with concrete to stiffen the same. In this type of application the posts are positioned to protect the door opening but if they are hit by a lift truck with any particular force, they will bend or become dislodged from the embeddment in the concrete floor and become utterly useless, it requiring considerable repair work in order to replace or repair the damaged posts. It is therefore desirable to have a guard post which may be positioned at the loading door opening and which will restrain the handling equipment from striking the door opening. The guard posts should be self supporting and capable of absorbing an impact with the handling equipment used in a warehose, and if struck with a sufficient severe impact be capable of being quickly and easily replaced. It is therefore an object of the present invention to provide a guard post that is positioned at the opening of a loading dock door in a building which will provide protection to the door opening and in particular to the guide rails of an overhead door that would be positioned in the opening.
SUMMARY OF THE INVENTION
The present invention provides an impact resistant guard post for the protection of the loading door apparatus in a warehouse. The post comprises an upright element preferably formed of an angle iron which has a base plate that is anchored to a floor and has a pair of brace members secured to the upright element to extend therefrom at an acute angle. Each brace member is inclined at approximately 30° to the floor surface and is anchored to the floor by a foot plate.
An object of the invention is to provide a guard post located at a door opening of a warehouse building which will protect the opening hardware from being damaged by load handling equipment.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing guard posts of the instant invention installed in place in an opening in a building;
FIG. 2 is an enlarged side elevational view with parts broken away showing the orientation of the guard posts and the door opening;
FIG. 3 is a vertical front elevational view of the guard post;
FIG. 4 is a top view partly in section showing the guard post and its relationship in plan to the door opening in the building.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is concerned with a guard post which will protect an opening in a building, and more particularly the opening in a building of a warehouse type which has a loading dock to which trailer trucks and other vehicles would use and be loaded from the warehouse by handling equipment such as lift trucks and the like. The guard post is designed to be placed adjacent the edge of the opening on either side thereof and thus the guard post is deployed in pairs, there being a righthand guard post assembly and a lefthand guard post assembly.
Referring to the drawings, the guard post assembly comprises a base plate 11, which is provided with two apertures therethrough designated 12 and 13. Secured to the base plate and rising vertically therefrom is the guard post generally designated 14 commonly known as an angle iron which is composed of a pair of plates that are right angularly arranged to each other and which are designated 15 and 16. The guard post is securely fastened to the base plate 11 as by welding and preferably rises from the base plate a distance of approximately one meter in order to provide the necessary protection with the utilization of most load handling equipment, although it will be understood that it can vary in its vertical extent depending upon a particular application. Extending from the inner face of the element 15 are a pair of brace members 20 and 21 which extend away from the member 15 at an acute angle thereto and at an acute angle to each other. The brace members may be conveniently made from tubular stock, the brace member 20 being secured as by welding at 22 to an upper extent of the guard post 14, while the member 21 is secured as by welding at 23 to a lower extent of the guard post 14. The bottom or outermost ends of the brace members are provided with foot plates 25 and 26 and terminate at a level which is on the same planar extent of the base plate 11 at an angle to the foot plate on the order of 60°. The foot plates 25 and 26 whose position relative to members 20, 21 may vary, are respectively provided with apertures 27, 28.
The building in which the guard posts are utilized is provided with the usual outer wall 30 that may be of suitable masonry material or any other normal building material and is normally provided with a protective opening plate such as 32. The opening is conventionally secured by an overhead door 35 which, as is well known to those skilled in the art, is made up of a plurality of sections that are guided for upward movement by guide rails such as 36, 37 and extending from a hinge assembly, such as 38, is a shaft 39 that carries a roller 40 that engages in the rails such as 36 and 37.
As will be apparent particularly by examining FIG. 4, it will be seen that the guard post of the instant invention has the face of member 15 substantially in line with the opening through the building wall. Further, the guard post is positioned so that the distance between it and the rails 36 and 37 is small, something on the order of 50 millimeters and will be secured in place by the use of lag bolts or other suitable fastening means that will grasp the floor which may be concrete or the like securely.
It would be apparent that if a fork lift or other load-handling equipment truck strikes the guard post that the brace members 20 and 21 will support the post from deflection and under normal operating conditions will prevent the post from being dislodged. Also because of the proximity to the opening, the load and/or the tines of the fork lift will be prevented from striking the guide rails such as 36 and 37. It will be further apparent that the positioning of the brace members 20 and 21 is such that a blow delivered to the guard post will substantially resist any movement or bending of the guard post.
The present invention, therefore, provides a guard post for placement at the opening of a loading lock door which will protect the door and particularly the guide rail for an overhead door from impact by virtue of handling equipment such as lift trucks and the like. Further, if the guard post is severely damaged by a blow, it may be easily replaced without the necessity of expensive construction and incident damage to a concrete floor or other support floor on the inside of the building adjacent the loading dock door.
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A guard post to prevent damage to the doorway of a loading dock and in particular damage to the guide rails for an overhead door is disclosed. The guard post is anchored and braced to the floor in close proximity to the opening of the loading dock and blocks contact of a lift truck with the guide rails of the door that are located on the interior face of the loading dock opening.
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RELATED APPLICATION
This application claims the benefit of provisional application Ser. No. 60/352,117 filed Jan. 24, 2002 entitled ANTI-EXPLOSIVE FERTILIZER COATINGS, the teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with a coating and methods of applying the coating to agricultural grade fertilizer particles. The coating inhibits the adsorption and absorption of hydrocarbons into the pores of the fertilizer particles thereby reducing the efficacy of the fertilizer as an oxidizing source in the production of incendiary devices. More particularly, the invention is concerned with coatings containing at least one polymer and methods of applying the coating to fertilizer products. The invention has particular utility in the deterrence or prevention of agricultural grade fertilizers and industrial grade ammonium nitrate being used to create weapons of terror.
2. Description of the Prior Art
Some common agricultural grade fertilizers generally comprise compounds which serve as excellent oxidizing agents, ammonium nitrate being one such compound. Generally, the fertilizer particles contain pores into which a number of other chemical agents can infiltrate, including hydrocarbon materials. The combined ammonium nitrate/fuel infiltrated particle is commonly referred to as ANFO (ammonium nitrate fuel oil). The article “Blasting Products” of the ANFO Manual distributed by El Dorado Chemical Company (St. Louis, Mo.), a copy of which is submitted herewith, is hereby incorporated by reference. When supplied with an ignition source, the hydrocarbon material acts as a fuel that is oxidized by the fertilizer particles. The resulting chemical reaction can release considerable amounts of energy, especially when the reactants are present in substantial quantities. To be most effective as an explosive, the ANFO will comprise about 5.7% by weight fuel oil. It is understood that when alternative sources of hydrocarbon fuel are used the fuel:ammonium nitrate ratio may need to be altered to achieve a stoichiometrically balanced mixture.
Both hydrocarbon fuels and fertilizers are readily available and relatively inexpensive products thereby making them excellent raw materials for producing renegade incendiary devices. The Oklahoma City bombing incident is one tragic example of how such materials may be used to perpetrate large-scale, terrorist atrocities.
During the manufacturing process, fertilizer particles are coated with an anti-dusting agent in order to reduce the amount of fertilizer dust produced during handling of the particles.
A commonly used anti-dusting agent is Galoryl (Lobeco Products Inc., Lobeco, S.C.) which is hydrocarbon based and is sprayed on during the manufacturing process. Being hydrocarbon based, this coating does not inhibit the infiltration of other hydrocarbon materials that may be used in constructing an incendiary device. Additionally, the anti-dusting agent does not form a protective barrier film encapsulating the entire fertilizer particle thereby leaving numerous pores exposed.
In order to prevent the misuse of ammonium nitrate in improvised explosives, it is necessary physically separate the fuel from the ammonium nitrate and also prevent the penetration of the liquid fuel into the fertilizer particles. If the fuel does not enter the interior of a sufficient number of particles in an optimal amount, the utility of ammonium nitrate particles as an oxidizer is substantially reduced or completely eliminated. There is a real need in the art for a fertilizer particle coating which forms a barrier that inhibits hydrocarbon infiltration of the fertilizer pores, and which will not alter the effectiveness of the fertilizer for its intended agricultural applications.
SUMMARY OF THE INVENTION
The present invention overcomes the problems outlined above and provides a coating for use with agricultural grade fertilizers and industrial grade ammonium nitrate. The coating should comprise a solution including at least one material which exhibits one or more of the following properties: substantially water soluble, substantially hydrocarbon insoluble, and capable of forming a film.
As used herein the term “substantially water soluble” means that the material may be contacted with water or a water-containing solvent mixture for a period of time up to approximately 24 hours and be transformed into a solution that contains at least 1% w/w of the material. The solution should be relatively stable meaning that the solute will not precipitate out of solution for at least about 3-4 hours. Various procedures may need to be employed to achieve this dissolution, such as heating and agitation. As used herein, the term “substantially hydrocarbon insoluble” means that the material will not dissolve in hydrocarbons to an extent greater than about 10% w/w upon exposure for a period of time up to approximately 48 hours at temperature and conditions of use.
With respect to simple conventional coating techniques, the pH of the solution may also play a role due to its effect on ammonia volatilization. Other coating techniques may reduce or eliminate the effect that pH has on ammonia volatilization. In preferred embodiments using the coating techniques which would have an effect on ammonia volatilization, the coating should have a pH of about 7.0 or less, preferably about 6.5 or less and more preferably about 5.5 or less. Those of ordinary skill in the art of coating will be able to use and develop coating methods which eliminate or reduce the volatilization of ammonia regardless of the pH of the coating. For example, spray drying or using a fluidized bed allow use of coatings with pH's above 7.0.
There is a wide range of materials which may be suitable for use in accordance with the present invention. Such materials include various natural and synthetic gums, starches and starch derivatives, polyethers, polysaccharides, polycarboxylates, poly-sulfonates, a wide range of monomers, polymers and copolymers, and combinations thereof. Among those materials for use with the invention are compositions that contain various mineral salts in addition to or instead of polymeric materials. Useful materials also include those that are known in the art of product formulation as flame and/or fire retardants. These include but are not limited to various boron-containing compositions such as borates, various metal salts including polymeric metal salts, oxides, carbides, nitrides, borides, silicates including polysilicates, silicides, aluminum-containing compositions, sulfates, phosphates, polyphosphates, chlorides, bromides, polymolybdates, molybdate salts, halogenated (particularly brominated) water-dispersible compounds with molecular weights above about 200 AMU. Ammonium phosphates are particularly preferred fire or flame retardant materials. As used herein, ammonium phosphate refers to any ammonium salt of any phosphate, including but not limited to any one chemical or combination of chemicals from the following list: ammonium phosphate, NH 4 H 2 PO 4 ; diammonium phosphate, (NH 4 ) 2 HPO 4 ; ammonium polyphosphate, (NH 4 ) salt of
ammonium pyrophosphate, (NH 4 ) 2 H 2 P 2 O 7 ; ammonium metaphosphate, NH 4 PO 3 ; and ammonium orthophosphate. It is understood that such flame and/or fire retardant materials can be used alone in some instances, that is to say as the coating itself, or in combination with other materials suitable for use in the present invention. For example, ammonium phosphate may be used in combination with a polymer, and especially with those polymers disclosed herein.
It has even been found that ordinary water when applied to the fertilizer particles reduces the level of fuel oil infiltration by decreasing the total number of pores through dissolving and “re-drying” a portion of the fertilizer particle.
In one preferred embodiment, the coating material comprises a polymer, and more preferably a carboxylate polymer, especially one or more of those set forth in U.S. patent applications Ser. Nos. 09/562,579 and 09/799,210 which are hereby incorporated by reference as though fully set forth herein. Even more preferably the carboxylate polymer comprises a polymer of acrylic acid or it comprises at least two different moieties individually and respectively taken from the group consisting of A, B, and C moieties, recurring B moieties, and C moieties wherein moiety A is of the general formula
moiety B is of the general formula or
and moiety C is of the general formula
wherein R 1 , R 2 and R 7 are individually and respectively selected from the group consisting of H, OH, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl C 1 -C 30 , based ester groups (formate (C 0 ), acetate (C 1 ), propionate (C 2 ), butyrate (C 3 ), etc. up to C 30 ), R′CO 2 groups, and OR′ groups, wherein R′ is selected from the group consisting of C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups; R 3 and R 4 are individually and respectively selected from the group consisting of H, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups; R 5 , R 6 , R 10 and R 11 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 and the C 1 -C 4 alkyl ammonium groups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu, Ni, V, Cr, Si, B, Co, Mo, and Ca; R 8 and R 9 are individually and respectively selected from the group consisting of nothing (i.e., the groups are non-existent), CH 2 , C 2 H 4 , and C 3 H 6 , at least one of said R 1 , R 2 , R 3 and R 4 is OH where said polymeric subunits are made up of A and B moieties, at least one of said R 1 , R 2 and R 7 is OH where said polymeric subunits are made up of A and C moieties, and at least one of said R 1 , R 2 , R 3 , R 4 and R 7 is OH where said polymeric subunits are made up of A, B and C moieties.
In the case of the polymer coatings comprising A and B moieties, R 1 -R 4 are respectively and individually selected from the group consisting of H, OH and C 1 -C 4 straight and branched chain alkyl groups, R 5 and R 6 are individually and respectively selected from the group consisting of the alkali metals.
One preferred polymer useful with the present invention comprises recurring polymeric subunits formed of A and B moieties, wherein R 5 and R 6 are individually and respectively selected from the group consisting of H, Na. K, and NH 4 and specifically wherein R 1 , R 3 and R 4 are each H, R 2 is OH, and R 5 and R 6 are individually and respectively selected from the group consisting of H, Na, K, and NH 4 depending upon the specific application desired for the polymer. These preferred polymers have the generalized formula
wherein R 5 and R 6 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 and C 1 -C 4 alkyl ammonium groups (and most preferably, H, Na, K and NH 4 depending upon the application), and n ranges from about 1-10000 and more preferably from about 1-5000.
As can be appreciated, polymers useful in accordance with the present invention can have different sequences of recurring polymeric subunits as defined above. For example, a polymer comprising B and C subunits may include all three forms of B subunit and all three forms of C subunit. In the case of the polymer made up of B and C moieties, R 5 , R 6 , R 10 , and R 11 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 , and the C 1 -C 4 alkyl ammonium groups. This particular polymer is sometimes referred to as a butanedioic methylenesuccinic acid copolymer and can include various salts and derivatives thereof.
Another preferred polymer useful with the present invention is composed of recurring polymeric subunits formed of B and C moieties and have the generalized formula
Preferred forms of this polymer have R 5 , R 6 , R 10 , and R 11 individually and respectively selected from the group consisting of H, the alkali metals, NH 4 , and the C 1 -C 4 alkyl ammonium groups. Other preferred forms of this polymer are capable of having a wide range of repeat unit concentrations in the polymer. For example, polymers having varying ratios of B:C (e.g., 10:90, 60:40, 50:50 and even 0:100) are contemplated and embraced by the present invention. Such polymers would be produced by varying monomer amounts in the reaction mixture from which the final product is eventually produced and the B and C type repeating units may be arranged in the polymer backbone in random order or in an alternating pattern.
As noted above, it is possible to use polymers of the present invention in combination with other materials, such as fire and/or flame retardant materials. For example, one such combination would comprise a mixture of a polymer comprising B and C type repeating units and ammonium phosphate. When such a polymer comprising B and C type repeating units is used in combination with ammonium phosphate, the ammonium phosphate may comprise a substantial portion of the mixture. However, extremely high levels of ammonium phosphate do not impart appreciably better flame retardant properties in comparison to lower levels. Therefore, for purposes of the present invention, it is preferable that the mixture comprise between about 90-99% by weight polymer and 1-10% by weight ammonium phosphate, more preferably between about 93-97% by weight polymer and 3-7% by weight ammonium phosphate, and most preferably between about 94-96% by weight polymer and 4-6% by weight ammonium phosphate. Most preferably, ammonium phosphate comprises approximately 5% of the total weight of the polymer/ammonium phosphate mixture.
The polymers useful in accordance with the present invention may have a wide variety of molecular weights, ranging for example from 500-5,000,000, more preferably from about 1,500-20,000, depending chiefly upon the desired end use.
In many applications, and especially for agricultural uses, polymers used with the invention may be mixed with or complexed with a metal or non-metal ion, and especially ions selected from the group consisting of Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, Cr, Si, B, and Ca. Boron is especially preferred because it may reduce the explosivity or energy released during combustion of ANFO as demonstrated by its use in various fire retardant materials.
The coating may comprise an additional material dissolved or dispersed in the same solution as the first polymer described above. Such additional materials should be selected based on their ability to increase the hydrocarbon resistance of the coating. Examples of suitable materials include natural and synthetic gums, starches and starch derivatives, polyethers, polysaccharides, polycarboxylates, poly-sulfonates, and a wide range of polymers and copolymers. Polyvinyl alcohol (PVA) is one of the preferred materials in this respect. PVA is a material highly resistant to hydrocarbon diffusion to the point where protective gloves and fuel hoses are products made from PVA. PVA is available in a variety of grades with different hydrolysis levels and molecular weights. Higher molecular weights generally give rise to higher viscosity polymer solutions. Therefore lower molecular weights in the range of about 10,000 to 30,000 are preferred due to their ability to form thin films which coat the particle surface easily. High hydrolysis level PVA is also preferred because of its increased resistance to hydrocarbon diffusion compared to that of PVA with a lower degree of hydrolysis.
Solid PVA is not rapidly water soluble at room temperature and below, therefore it is preferable that PVA be used in companion with another material of the type previously described. The weight ratio of PVA to the other polymer should be between about 1:100 to 100:1, and more preferably between about 1:10 to 10:1 and most preferably about 1:3.
It is also within the scope of the present invention to provide a fertilizer coating comprising only PVA. As previously discussed, some agricultural applications will require fertilizer coatings which are more water soluble, in addition PVA is expected to be more expensive than other materials described above, therefore preferred embodiments of the invention contain PVA used in combination with other materials.
Coatings according to the invention should have a solids content of between about 5-70% by weight and more preferably between about 20-60% with the balance comprising water. The solids content largely depends upon the compatibility of the coating viscosity with the method of application to the fertilizer particles. It is most preferable that the fertilizer coating have a solids content of between about 10-30% by weight.
The coating is applied as a film to a fertilizer particle to form a coated fertilizer particle. Preferably the fertilizer particle used will be porous and will have a bulk density of about 40 to 60, more preferably about 40 to 50 and most preferably about 44 lbs/ft 3 . However, less porous fertilizer particles with higher bulk densities are also suitable for use in accordance with this invention. Preferred fertilizer particles for use with the current invention are monoammonium phosphate (MAP), diammonium phosphate (DAP), any one of a number of well known N—P—K fertilizer products, and/or fertilizers containing nitrogen materials such as ammonia (anhydrous or aqueous), ammonium nitrate, ammonium sulfate, urea, ammonium phosphates, sodium nitrate, calcium nitrate, potassium nitrate, nitrate of soda, urea formaldehyde, metal (e.g. zinc, iron) ammonium phosphates; phosphorous materials such as calcium phosphates (normal phosphate and super phosphate), ammonium phosphate, ammoniated super phosphate, phosphoric acid, superphosphoric acid, basic slag, rock phosphate, colloidal phosphate, bone phosphate; potassium materials such as potassium chloride, potassium sulfate, potassium nitrate, potassium phosphate, potassium hydroxide, potassium carbonate; calcium materials, Such as calcium sulfate, calcium carbonate, calcium nitrate; magnesium materials, such as magnesium carbonate, magnesium oxide, magnesium sulfate, magnesium hydroxide; sulfur materials such as ammonium sulfate, sulfates of other fertilizers discussed herein, ammonium thiosulfate, elemental sulfur (either alone or included with or coated on other fertilizers); micronutrients such as Zn, Mn, Cu, Fe, and other micronutrients discussed herein; oxides, sulfates, chlorides, and chelates of such micronutrients (e.g., zinc oxide, zinc sulfate and zinc chloride); such chelates sequestered onto other carriers such as EDTA; boron materials such as boric acid, sodium borate or calcium borate; and molybdenum materials such as sodium molybdate. Of course, due to its explosive tendencies, ammonium nitrate is the most preferred fertilizer for purposes of the invention.
The coating is typically applied to the fertilizer particles at a level of from about 0.0001-4% by weight, and more preferably from about 0.01-1.0% by weight, and most preferably 0.25-0.5% by weight based upon the weight of the fertilizer taken as 100%. Additionally, when a coating material comprising carbon is employed, the quantity of carbon comprises about 0.2% by weight or less of the total weight of the coated particle. The film or coating should limit hydrocarbon infiltration of the fertilizer particle pores in comparison to an uncoated fertilizer particle, and preferably should reduce hydrocarbon infiltration by at least 10% in comparison to an uncoated fertilizer particle. Even more preferably, the film should reduce hydrocarbon infiltration by at least 50% and most preferably by at least 80%. Such hydrocarbon materials include fuel oil, diesel fuel, grease, wax, and other materials containing a preponderance of hydrocarbons. By preventing or inhibiting the infiltration of hydrocarbon materials into the fertilizer particle, the fertilizer particles have reduced explosivity tendencies, thereby reducing their usefulness as incendiary devices.
Another method of reducing the explosivity of agricultural grade fertilizer particles and industrial grade ammonium nitrate embraced by this invention is to selectively supply a quantity of water to the fertilizer particles. In so doing, a portion of the fertilizer particles dissolves thereby reducing the number of pores available for hydrocarbon infiltration. Finally, it is necessary to dry the fertilizer particles in order to avoid imparting to the quantity of particles undesirable characteristics such as clumping and caking.
Thus far, the description above has focused on the coatings and coated fertilizer particles on an individual particle level. When dealing with large quantities of coated fertilizer particles, especially coated ammonium nitrate particles, it is important to note that complete coating coverage of each individual particle is not always essential. It is possible for the coatings of the invention to reduce or completely eliminate the explosivity of the quantity of particles as a whole so long as a plurality of the particles are at least partially coated. It is even possible to mix quantities of coated and uncoated particles together and still produce a fertilizer mixture that has reduced explosivity characteristics. For even when fuel oil is added to this mixture of particles, the coated particles will absorb little or no fuel and some of the uncoated particles will become super-saturated with fuel oil. Both types of particles reduce the explosivity of the entire quantity of fertilizer particles. It may seem surprising that a super-saturated particle will reduce explosivity of the entire batch, however, if too much oil is added, the ability of the ammonium nitrate to oxidize the fuel oil is reduced. As noted in the El Dorado Chemical article referenced and incorporated above, there is an optimal percentage of fuel oil (about 5.7%) which maximizes the theoretical energy released in the detonation of ANFO. Adding more or less fuel oil tends to decrease the amount of energy released upon detonation. Therefore, such super-saturated fertilizer particles act to reduce the explosivity of the entire quantity of fertilizer particles.
Advantageously, coatings of the current invention also inhibit the formation of fertilizer dust normally associated with fertilizer handling. Therefore, coatings according to the invention are suitable for use as anti-dusting agents, and may be employed in place of current hydrocarbon based anti-dusting agents.
Generally, methods of forming coated fertilizer particles in accordance with the invention comprise the steps of providing a fertilizer particle and coating the particle with a film comprising at least one material selected from the group consisting of natural and synthetic gums, starches and starch derivatives, monomers and polymers and copolymers selected from the group consisting of polyethers, polysaccharides, polycarboxylates, polysulfonates, and mixtures thereof. Polymer and copolymer coatings are preferred. The coating may be applied to the fertilizer particle in any manner commonly known or used in the art, such as spraying. The precise coating procedure employed will be based an a number of factors including but not limited to the viscosity of the coating, particle surface morphology, particle size, density, and application equipment available. Regardless of the coating method used, it is preferred that the coating be applied in such a manner as to form an evenly distributed film which will provide an effective barrier against hydrocarbon infiltration of the fertilizer particle. Generally preferred embodiments of the fertilizer coating comprise a solution including at least one of a substantially water soluble material, a material substantially insoluble in hydrocarbon materials, a material capable of forming a film including a quantity of polyvinyl alcohol dissolved or dispersed therein, and combinations thereof.
Preferred embodiments of the coated fertilizer particle of the invention comprise a fertilizer particle coated with a film comprising at least one material. It is more preferable for the material to be substantially water soluble, or substantially insoluble in hydrocarbon materials or still more preferably substantially water soluble and substantially insoluble in hydrocarbon materials.
Preferred methods of forming the coated fertilizer particle of the invention comprise the steps of providing a fertilizer particle and coating the particle with a film comprising at least one material. Again, it is preferable for the material to be substantially water soluble, or substantially insoluble in hydrocarbon materials or still more preferably substantially water soluble and substantially insoluble in hydrocarbon materials.
The coating of the invention may also be used in combination with a fertilizer particle. It is generally preferable for the coating to comprise at least one material. It is preferable that the material be substantially water soluble, substantially insoluble in hydrocarbon materials, or capable of forming a film, or a combination thereof.
Ammonium nitrate is the most preferred fertilizer particle for use with the invention because, when combined with a fuel source such as hydrocarbon materials, it acts as a powerful oxidizer. When brought into contact with an ignition source, the ammonium nitrate has the potential to violently react with the fuel source releasing considerable amounts of energy.
The most preferred polymer coating of the invention comprises a quantity of PVA dissolved or dispersed in a solution comprising a BC type polymer as described above in a weight ratio of about 1:3 (PVA:BC). The most preferred coating will comprise about 10-30% polymer solids and will be water soluble, insoluble in hydrocarbon materials, capable of forming a film and will have a pH of about 7.0 or less. Most preferably the polymer coating will be applied to an ammonium nitrate fertilizer particle in Such as manner so as to form an evenly distributed film providing an effective barrier to hydrocarbon infiltration of the fertilizer particle pores.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following examples describe preferred compositions and methods in accordance with the invention. It is to be understood that these examples are illustrations only and nothing therein should be deemed as a limitation upon the overall scope of the invention.
EXAMPLE 1
In this example, agricultural grade ammonium nitrate particles were coated with various polymeric materials, as set forth in Table 1, and then exposed to diesel fuel. The amount of diesel fuel retained by the coated particles compared to the original amount of diesel fuel added was then determined.
The ammonium nitrate particles were coated with the respective polymers according to one of the following two procedures. The most typical procedure was to weigh out an amount of the polymer solution to be coated onto a petri dish having a diameter of about 90 mm. All polymer solutions used in this experiment contained 50% by weight polymer. An appropriate amount of ammonium nitrate particles were weighed out and rolled onto the petri dish. The dish was then covered and the particles were vigorously swirled across the coating materials for several minutes. An alternative coating procedure was to weigh out an appropriate amount of ammonium nitrate particles and place them into a plastic bag equipped with a closure. The appropriate amount of polymer to be coated onto the ammonium nitrate particles was weighed and added to the bag. The bag contents were agitated vigorously for several minutes.
The coated granules were then placed into 20 mL glass vials and then saturated with diesel fuel. The diesel fuel is poured on top of the particles and then mixed with them by shaking the vial for approximately 10 minutes. The mixture was then allowed to stand for another 5 minutes to provide the fuel with the opportunity to soak into the particle and achieve intimate contact with the ammonium nitrate particles. The particles were then removed from the vials and placed on a filter with vacuum flow assist. The particles were then thoroughly washed with about 50 mL of tetrahydrofuran (THF). The filter liquid was discarded. The particles were collected from the filter and dried in a vacuum oven for about 10 minutes at about 25 in. Hg at a temperature of about 50° C. before being weighed. The difference between the coated particle weight and the washed and dried particle weight is the amount of fuel the particle retained. The results of these experiments are set forth in Table 1.
TABLE 1
Ammonium
Sample
Treatment type (% total particle
Treatment (g 50%
nitrate particle
Diesel fuel
Washed & dried
w/w % original
% wt. fuel retained/
#
weight attributed to coating)
polymer soln.)
weight (g)
(g)
weight (g)
fuel retained
wt. washed particle
0
None
0.000
9.050
1.021
9.118
7
0.7
1
BC acid (1%)
0.205
10.073
1.014
10.020
ND
ND
2
BC NH4 salt, pH 3.5 (1%)
0.208
9.984
1.040
9.971
ND
ND
3
BC NH4 salt, pH 7 (1%)
0.208
9.986
1.020
10.020
ND
ND
4
BC Na salt, pH 4 (0.5%)
0.100
10.057
1.083
10.079
ND
ND
5
None
0.000
11.658
1.165
11.794
8
0.8
6
AB Na salt, pH 7 (1%)
0.220
10.266
1.154
10.646
23
2.5
7
C acid (1%)
0.215
10.289
1.142
10.289
ND
ND
8
AB Na salt pH 7 (1%)
0.210
10.146
1.256
10.508
20
2.5
9
BC NH4 salt pH 3.5 (0.5%)
0.108
10.315
1.115
10.318
ND
ND
10
B acid (0.5%)
0.102
10.021
1.144
10.037
ND
ND
11
BC NH4 salt, pH 3.5 (0.25%)
0.057
10.190
1.168
10.279
5
0.6
12
BC NH4 salt, pH 3.5 (0.125%)
0.057
20.206
2.212
20.359
6
0.6
13
B acid (0.25%)
0.056
10.415
1.221
10.418
ND
ND
14
C acid (0.25%)
0.059
10.227
1.178
10.251
ND
ND
15
BC acid (0.25%)
0.062
10.652
1.173
10.632
ND
ND
16
BC acid (0.125%)
0.060
19.584
2.657
19.608
ND
ND
17
Polyacrylic acid (0.25%)
0.067
10.044
1.051
9.905
ND
ND
As used in Table 1 and subsequently:
AB indicates a 1:1 mole:mole copolymer of maleic acid and vinyl acetate prepared as disclosed in U.S. patent application Ser. No. 09/562,579; BC indicates a 1:1 mole:mole copolymer of maleic acid and itaconic acid prepared as disclosed in U.S. patent application Ser. No. 09/562,519; B indicates a homopolymer of maleic acid obtained from Rohm and Haas Chemicals (Philadelphia, Pa.); C indicates a homopolymer of itaconic acid prepared according to a method similar to that of BC; Polyacrylic acid obtained from Aldrich Chemical Company (Milwaukee, Wis.); and ND indicates that the measurement was not detectable or below what could be measured.
Next a series of experiments were performed using the same test procedure above, however the diesel infiltration time was extended to 24 hours. The results are listed in Table 2.
TABLE 2
Ammonium
Sample
Treatment type (% total particle
Treatment (g 50%
nitrate particle
Diesel fuel
Washed & dried
w/w % original
% wt. fuel retained/
#
weight attributed to coating)
polymer soln.)
weight (g)
(g)
weight (g)
fuel retained
wt. washed particle
18
None
0.000
10.451
1.130
10.623
15.22
1.62
19
BC acid (0.25%)
0.053
10.134
1.059
10.299
13.08
1.34
20
B acid (0.25%)
0.053
10.137
1.176
10.235
6.08
0.70
21
C acid (0.25%)
0.062
10.061
1.165
10.160
5.84
0.67
22
Acrylic acid (0.25%)
0.067
10.233
1.075
10.364
9.07
0.94
23
AB (0.25%)
0.100 (g 25% soln.)
10.313
1.121
10.385
4.19
0.45
24
BC acid (0.25%)
0.107 (g 25% soln.)
10.131
1.091
10.210
4.79
0.51
The above data demonstrates that even incomplete and imperfect practice of the invention disclosed herein is highly beneficial. It was further determined that polycarboxylate-containing materials are useful barrier coatings and help decrease diesel fuel infiltration into ammonium nitrate particles under the experimental conditions tested. However, the materials do not give perfect protection when used alone at lengthy exposure times.
EXAMPLE 2
The purpose of this example was to optimize diesel fuel resistance of two-component coatings. In these experiments, porous paper, S&S paper type #404 (Schleicher & Schuell, Dassel, Germany), was used to simulate porous ammonium nitrate particles. Upon examination using a low-power microscope, the porous paper had generally similar porosity to that of high porosity ammonium nitrate. The porous paper had the added advantage of being of substantially uniform porosity whereas the ammonium nitrate granules were of varying shape and porosity.
In the first experiment, the optimal percent of polymer solids in a coating was determined. The polymer coatings tested were polymaleic acid, sodium polymaleate at pH 3.5, itaconic acid homopolymer, polyacryilc acid, and BC acid polymer. The coating was applied to an 80×80 mm area on a sheet of porous paper by placing small drops of aqueous coating solution to the paper and spreading them to cover the test area using an inert plastic ruler. The coating was allowed to dry. Next, diesel fuel was dripped onto the coated area and the penetration, or lack thereof, was noted. It was determined that the range of polymer solids in the coating could be about 5-70% by weight, with the range about 10-30% by weight being preferred.
The next experiments involved addling polyvinyl alcohol, PVA, (Celvol 103 by Celanese Chemicals, Dallas, Tex.), a chemical known for its resistance to hydrocarbon diffusion, to the BC acid polymer coating in order to increase the coating's resistance to diesel fuel penetration. BC acid polymer was used because its performance was superior to the other coatings in the porous paper test described above. Because PVA is much more expensive than BC acid polymer it was desirable to determine the optimal ratio of PVA to BC acid polymer. The optimal ratio of PVA to BC acid polymer was about 1:3 by weight. The optimal mixture was prepared at about 20% w/w total dissolved solids by mixing appropriate amounts of water and BC acid polymer solution at room temperature. In this solution, PVA was dissolved or dispersed and the solution subsequently heated to about 90-95° C. with very vigorous, non-aerating agitation. The mixture was cooled to room temperature, at which time it had a consistency suitable for making coatings. The coating was applied to porous paper in the manner described above. The coating was hard, low-color, smooth to the touch after drying, non-hygroscopic and easily dissolved in water. The percent solids used is dictated by the compatibility with the application technique chosen. In practice, any percent solids solution can be used as long as the coating solution is sufficiently mobile under application conditions to create useful coatings. A useful coating is one that provides an effective barrier to fuel infiltration by being a thin film that coats and covers the particle surface.
Through these experiments, and for the chosen application method, it was determined that a 1:3 weight ratio of PVA to BC acid polymer was the most effective coating in preventing diesel fuel infiltration.
EXAMPLE 3
In this example, an alternative method of applying the polymer coating to the fertilizer particles was explored. The method involved placing a piece of flat round filter paper (S&S paper type #404) into a 5.5 inch diameter petri dish so that the paper occupies the entire bottom of the dish. About 2.9 g of the 20% w/w solution prepared in Example 2 is spread onto the paper until the paper is saturated with the liquid, but not to the point where there is liquid on the paper surface. The filter paper should be slightly moist to the touch. About 13 g of ammonium nitrate particles are poured onto the paper surface and rolled around the petri dish for about 1 minute, then removed. The particles are allowed to dry for 15 minutes in the air. This method was found to be highly effective as particles coated using this method do not tend to stick together and are dry and smooth to the touch.
Any method of particle coating known in the art, such as spraying, may be employed to apply the coating to the ammonium nitrate granules so long as the method results in a sufficient fraction of the surfaces of the fertilizer particles being coated to a sufficient degree. It is preferable to have particles coated with a relatively thin layer of coating so as to reduce the expense involved, preserve fertilizer analysis values, reduce water levels added to the fertilizer and reduce material handling requirements.
EXAMPLE 4
In this experiment, small particle size, high porosity ammonium nitrate granules coated with a factory applied anti-dusting agent, Galoryl, were tested for diesel fuel infiltration.
Typically, porous materials with high surface area per unit weight are very difficult to coat effectively, in addition, such material is optimized for high and very rapid uptake of fuel.
The granules, obtained from El Dorado Chemical Company (St. Louis, Mo.), were first tested without applying any polymer coating according to the diesel fuel absorption method described in Example 1. The particles retained about 49% of the diesel fuel added to them, and had a fuel content of about 5% w/w after a solvent wash as described in Example 1.
Another batch of granules were tested after removal of the factory applied anti-dust coating. The anti-dust coating was removed by washing the particles several times in THF and subsequently drying the particles under vacuum overnight at 50° C. The de-coated particles had very similar fuel absorption characteristics to those with the factory applied anti-dusting coating.
Next, samples of both factory coated and de-coated particles were coated with the 1:3 weight ratio PVA to BC polymer described in Example 2 and tested for diesel fuel infiltration using the method described in Example 1, however the exposure time was increased to 15 minutes rather than 5 minutes after the 10 minute mix time. The diesel infiltration for de-coated particles was below 0.2-0.3% of the particle weight with less than 3% of the original fuel being retained. The factory coated particles did not absorb any detectable diesel fuel.
This experiment illustrates the high barrier performance of the composition and coating application method under conditions which are generally very favorable for diesel fuel absorption and retention, such as small particle size, high surface area per unit weight, and high porosity. It is understood that for standard agricultural grades of ammonium nitrate, which is normally non-porous and has large particle sizes with low surface areas, this coating method would be even more effective.
EXAMPLE 5
This example demonstrates that treatment with water alone substantially improves the inhibition of hydrocarbon infiltration into fertilizer particles. The procedure of Example 1 was followed with two exceptions. The first exception was that the particles for this example were soaked in diesel fuel for 10 minutes. The second exception was that the particles were washed with methylene chloride rather than THF. Generally, diesel fuel was added to El Dorado Chemical's low density Ammonium Nitrate coated with Galoryl. Particles with no additional coating were then compared with particles which were sprayed with a 0.5 gal/ton coating of the previously described 50% BC polymer, particles which were sprayed with a 1.0 gal/ton coating of the previously described 25% BC polymer, and with particles that were sprayed (treated) with 0.5 gal/ton of water. The particles were then soaked with diesel fuel for 10 minutes and washed with methylene chloride before being tested for their differences in diesel fuel oil retention. The results of this example are provided below in Table 3.
TABLE 3
Concentration
% Difference in Diesel Oil Retention
Treating Agent
(Gal/ton)
Compared With The 50% BC Polymer
CK-None
—
100
50% BC
0.5
0.00
25% BC
1.0
0.03
Water
0.5
25.00
As shown by these results, simply spraying the particles with water helps to increase their resistance to hydrocarbon penetration in this manner, water does not serve as a coating. Instead, the particle surface is melted away, thereby permitting less intrusion of hydrocarbons into pore spaces.
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Coatings for agricultural grade fertilizer particles and industrial grade ammonium nitrate are provided which when applied to particles form a protective film which acts as a barrier to inhibit or prevent hydrocarbon infiltration of the fertilizer particle pores and also to physically separate the fertilizer particles and hydrocarbon materials. In so doing, the coating greatly reduces the efficacy of the fertilizer particles as an oxidizing agent for use in incendiary devices, thereby deterring or preventing the use of agricultural grade fertilizers or industrial grade ammonium nitrate in creating weapons of terror.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of, claims priority to, and incorporates by reference in its entirety, U.S. patent application Ser. No. 09/610,540, entitled “METHOD AND SYSTEM FOR MANAGING AND CONDUCTING A NETWORK AUCTION,” filed Jul. 7, 2000 which claims priority to and incorporates by reference in its entirety, U.S. Provisional Patent Application No. 60/143,021, filed Jul. 9, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the field of electronic commerce and more particularly to a method and system for managing person-to-person payment transactions, including auction transactions, over a network, such as the Internet.
[0004] 2. Description of the Related Art
[0005] Currently, person-to-person payment transactions are conventionally performed using, for example, cash, personal checks, a money order or the like. Using any one of these traditional payment methods at least one party to the transaction assumes certain risks. For example, in the case of a goods for cash transaction, the buyer is handing over cash for a good or goods which may not conform as promised by the seller to his/her expectations. In the case of a seller who accepts a check from a buyer, the seller is taking a chance that the check will clear. The seller may be able to decrease his/her chance of loss, by holding onto the good(s) until the check clears, but this then causes a delay to the buyer who must wait for the check to clear prior to receiving his/her paid for good(s). These are but a few examples of the risks that are assumed in the performance and settlement of person-to-person payment transactions. In addition, there is a need for consumers to be able to facilitate person-to-person payments, for example, to facilitate birthday presents or reimbursement of funds that were spent without a merchant being involved that eliminates the necessity for consumers to use paper checks or cash as the payment vehicle between two individual parties.
[0006] A specific application of person-to-person payment transactions, is to Internet auction transactions. In the performance of these auction transactions, a buyer does not really know if the purported seller actually exists, and neither does a seller in such an auction know whether the purported buyer actually exists. Therefore, a buyer who enters the winning bid takes a chance on the existence of the purported seller, as well as whether he or she will ever get the merchandise on which the bid was entered. Likewise, a seller who accepts the winning bid takes a chance on the existence of the buyer who purported to enter the winning bid. Further, since payments for an on-line auction purchase are actually being made person-to-person via check or money order, it takes an inordinate amount of time to clear checks through the current Automated Clearing House (ACH) systems, which slows down the purchasing process considerably via the on-line auction context.
[0007] Typically, in such an auction, a user at a terminal, such as the user's personal computer (PC) accesses an auction page on the Internet, such as E-BAY and goes through a registration process. Registering basically means that the user at the user's PC enters the user's address, such as an e-mail address, and an e-mail is sent to the user, for example, at the user's PC, which tells the user that he or she is allowed to bid. The user is also given, for example, a bidding name, and the user sets up a password on the system.
[0008] It is well known that anyone, can set up an Internet account for an e-mail address with a service provider, such as AOL or the like, and it is possible for a party to secure an e-mail address while concealing his or her true identity. It is also possible for someone to use another party's e-mail address on an unauthorized basis, and e-mail addresses are commonly stolen and used without the owner's authorization. In short, there are no guarantees associated with an e-mail address as to any identifying characteristics (e.g., age, gender, status) of the user of the e-mail address.
[0009] When the user registers on the auction page with the user's e-mail address and receives a bidding name, the user is ready to bid or list with the auction site. In the case of auction sites as with auction houses, at least one of the seller and buyer pays a fee for the opportunity to use the auction site. Usually the seller pays for the ability to list and sometimes pays an additional fee in the form of a percentage of the eventual selling price. The procedure varies for some auction houses, such as SOTHEBY'S, in which the buyer pays the fees. However, as a general rule, it is the seller who pays the fees, and the auction house generally bills or invoices the seller once a month. Upon receipt of the invoice, the seller generally pays, for example, by writing a check, although sometimes sellers can pay by credit card In the case of Internet auction sites, most people selling at auction over the Internet are not what we typically think of as merchants. Rather, they are simply individuals, and when they sell something, they are not usually equipped to receive payment by any means (e.g., credit card) other than by check, money order, or the like. This causes inconveniences for both parties, since the buyer must actually write a check or obtain a money order and then the buyer must wait until the seller is satisfied that the check will clear, etc., before the good(s) are transferred.
[0010] Internet auctions include, for example, normal auctions in which people enter bids and the bid price goes up as people bid higher and higher, as well as what are called Dutch auctions. In a Dutch auction, the process begins at a certain price, and the price goes down until somebody makes an offer at the current price. In a Dutch auction, effectively, someone wins the bid, because there are time frames. In other words, the bids are scheduled to end at a certain time, so they do not go continuously. In any event, when the bidding ends, the seller notifies the buyer via e-mail that the buyer has won the bid and asks the buyer to send the seller payment, such as a check or a money order, for the purchase price plus, for example, a certain amount for shipping and handling.
[0011] Upon receipt of such e-mail, it is up to the buyer to either write a personal check and/or get a certified check or a money order, which means a trip to the Post Office or the financial institution, and send the check or money order, for example to an address for the seller given in the e-mail. It is readily apparent that when the buyer sends the check or money order to the seller, the buyer takes a substantial risk that the seller actually exists and/or that the buyer will actually receive the good(s) for which the buyer has paid. The buyer expects the seller to package and ship the good(s) to the buyer when the seller receives a money order or a certified check. However, if the buyer pays by personal check, the seller typically waits several weeks for the check to clear before packaging and shipping the good(s). While one auction house has recently started a voluntary verification process in which users can have themselves “verified” by paying a fee and sending information to a credit bureau, the process is voluntary and does not take place on both sides of a transaction.
[0012] Accordingly, there is currently a tremendous amount of uncertainty in Internet auction transactions, for example, as to whether buyers or sellers really exist. There is likewise also considerable uncertainty as to whether or not buyers will pay, and if they do pay, whether the payment funds are good. Further, if the funds are good, there is a tremendous amount of uncertainty about whether the buyer will actually get the merchandise for which the funds were paid. The risk is a seller's risk, as well as a buyer's risk. The buyer risks not receiving the merchandise for which the buyer paid. The seller's risk lies, for example, in putting the seller's merchandise up for auction and receiving a winning bid, and waiting a month or more to discover that the buyer does not exist or sent bad funds for payment.
SUMMARY OF THE INVENTION
[0013] Settlement of an Internet auction transaction occurs through the system of the financial institution that is sponsoring the auction website. It is not necessary, for example, for a credit card settlement to go through a card association. Rather, it is simply a matter of running the settlement through the financial institution's system and, in effect, the buyer buys something, for example, for ten dollars, so the financial institution takes ten dollars from or charges the buyer's account ten dollars, and the seller sells something, for example, for ten dollars, so the financial institution gives the seller a credit on the seller's account for ten dollars. Thus, the settlement is very much like having the buyer and seller present together and exchanging the funds instantaneously. The settlement is reported as a transaction on the account statements of both customers.
[0014] It is a feature and advantage of the present invention to provide a method and system for managing auction transactions over the Internet which removes the risk of non-authentic buyers and sellers by authenticating the buyer and seller in a transaction from the buyer's and seller's account information, respectively.
[0015] It is a further feature and advantage of the present invention to provide a method and system for managing Internet auction transactions which avoids the risk of non-payment and delayed shipment of good(s) by settling the transaction on accounts of the buyer and seller in the transaction.
[0016] To achieve the stated and other features, advantages and objects, an embodiment of the present invention provides a method and system for managing Internet auction transactions by creating an auction website by, for example, a financial institution. The auction website is accessible by the financial institution's account holders (e.g., holders of checking, savings, credit card, and investment accounts). Thus, all buyers and sellers in auction transactions on the auction site, for example, have accounts with the financial institution, with settlements occurring between the accounts of the users at the financial institution. Payments are debited from the buyer's account(s) with a credit going to the account of the seller, less any fees. All charges occur internally, so no interchange is owed, for example, to a card association in connection with the transaction. Financial institution customers benefit from the system in that buyers and sellers are authenticated and settlement occurs virtually instantaneously.
[0017] 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 more apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0018] In the drawings:
[0019] FIG. 1 is a schematic of the parties to an auction transaction according to an embodiment of the present invention;
[0020] FIG. 2 is a registration process according to an embodiment of the present invention;
[0021] FIG. 3 is a registration process according to an embodiment of the present invention;
[0022] FIG. 4 is an auction payment process according to an embodiment of the present invention;
[0023] FIG. 5 is an auction payment process according to an embodiment of the present invention;
[0024] FIG. 6 is an auction payment process according to an embodiment of the present invention; and
[0025] FIG. 7 is an auction payment process according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring to FIG. 1 an embodiment of the present invention enables authentication of counterparties to an Internet auction transaction wherein both parties hold financial accounts with the provider of the auction website. An Internet auction transaction for an embodiment of the present invention involves, for example, a seller 10 at the seller's PC 12 and a buyer 14 at the buyer's PC 16 , each accessing the auction page of the website server 18 , for example, of a financial institution, over the Internet 20 or any other public or private network.
[0027] In an embodiment of the present invention, the seller is known to the financial institution as the holder of an account with the financial institution, and the buyer is likewise known to the financial institution as the holder of an account with the financial institution. Thus, there is a known financial institution account holder on both ends of the Internet auction transaction. The financial institution knows that both the seller and the buyer actually exist. When the transaction occurs, the payment is very simple, because the payment is made by the financial institution debiting the account of the buyer who bought the item at auction and crediting the account of the seller who sold it through an internal settlement system 22 . Therefore, it is known that the parties are dealing with actual people, or at the very least, active accounts and that once the transaction occurs, the seller will receive his or her funds. In a first preferred embodiment of the present invention, the funds transfer is virtually instantaneous, allowing the seller to have the benefit of the payment almost immediately. While in a second preferred embodiment of the present invention, the funds are held in escrow until the good(s) are received by the buyer, as discussed below.
[0028] Referring to FIG. 2 , in an embodiment of the present invention, a process for participating in the Internet auction website of the current invention begins with the potential seller and the potential buyer each registering with the financial institution's auction website S 2 , S 12 by providing at least an e-mail address and payment account information. In prompting the seller and buyer for payment account information, the financial institution queries whether or not the seller or buyer holds an account with the financial institution S 4 , S 14 . When a seller or buyer asserts that they have an account with the financial institution, the financial institution then verifies that the seller and buyer are in fact financial institution account holders, that the account numbers for each are valid, and that each is in good standing S 6 , S 16 . If the selected account is not found or is not in good standing, registration is denied under that selected account S 8 , S 18 . This may be accomplished by, for example, an application on the website server which accesses financial institution account data stored, for example, in a financial institution database. In the verification process, the financial institution confirms, for example, that the credit cards are not stolen, that the cards are good, that the credit card accounts are paid on time or that the selected accounts (e.g., checking, savings, brokerage) are in good standing. In other words, the financial institution confirms that the accounts are active and in good standing for purposes of financial transacting.
[0029] In an alternate embodiment, the buyer or seller may be prompted to select an alternate account under which to register. In this case, the system will again check the viability of the selected account prior to allowing registration. Though the verification is done over the Internet, a public network, account numbers are sent securely using, for example, encryption. Data transmission encryption techniques are well known in the Internet art and will not be discussed further within this application.
[0030] Once an active account is selected, the website issues the buyer or seller a registration ID S 10 , S 20 . This ID may take many forms, including a username/password combination selected by the buyer and seller or it may be an alphanumeric code/personal identification number (PIN) assigned randomly by the financial institution, wherein the financial institution associates the selected user/password combination or the assigned code with the buyer or seller's selected account number.
[0031] Once issued a registration ID, the seller and buyer may gain access to the auction portion of the website and sell or bid on good(s). A seller lists good(s) on the website under his/her registration ID S 22 . Similarly, a buyer bids on listed good(s) using his/her registration ID S 24 . Eventually, a buyer will win the bidding for a listed good(s) S 26 . In the embodiment described above, both the buyer and seller hold accounts with the financial institution running the auction website. This need not necessarily be the case.
[0032] Referring to FIG. 3 , non-account holders may also participate in the auction website if they hold credit cards from member associations or have other approved accounts with member financial institutions. Member associations and member financial institutions are pre-approved by the auction sponsoring financial institution. Similar to the registration process for the account holders, non-account holder sellers and buyers are prompted for payment account information and the financial institution queries whether or not the seller or buyer holds an account with a member association or member financial institution S 30 , S 40 . If no such account is held, then the buyer or seller is denied registration S 32 , S 42 . When a seller or buyer asserts that they have such an account with a member association or member financial institution, the sponsoring financial institution then verifies that the seller and buyer are in fact account holders with the member association or member financial institution, that the account numbers for each are valid, and that each is in good standing S 34 , S 44 . If the selected account is not found or is not in good standing, registration is denied under the selected account S 36 , S 46 .
[0033] Once an active account is selected, the website issues the buyer or seller a registration ID S 38 , S 48 wherein the sponsoring financial institution associates the assigned code with the buyer's or seller's selected account number held through a member association or member financial institution. When in possession of a registration ID, the seller and buyer may access the auction portion of the website and sell or bid on good(s). A seller lists good(s) on the website under his/her registration ID S 50 . Similarly, a buyer bids on listed good(s) using his/her registration ID S 52 . Eventually, a single buyer will win the bidding for a listed good(s) S 56 assuming the bid requirements, if any, set by the seller are met (e.g., minimum acceptable bid is met).
[0034] In the following embodiments, the procedure for finalizing the auction transaction is the embodiment where both the buyer and the seller have registration IDs under accounts of the sponsoring financial institution. These steps are similarly applicable, in most instances, to embodiments wherein either the buyer or seller or both have registered with the Internet auction website using accounts from other than the sponsoring financial institution i.e., from a member association or member financial institution. Differences in the process due to non-sponsoring financial institution account holders are addressed below.
[0035] Once the buyer has won the bidding for a seller's good(s), the auction site has a data packet which includes the good(s) associated with the seller's registration ID which is in turn associated with an account that the seller used to register with the auction website. Further, the data packet includes the buyer's registration ID which is in turn associated with an account that the buyer used to register with the auction website. Finally, the data packet includes the final price bid for the good(s). At this point, settlement of the transaction may begin.
[0036] Referring to FIG. 4 , in an embodiment of the present invention, the buyers and sellers having accounts with the sponsoring financial institution are prompted to select which account with the financial institution they wish to access for settling the transaction S 60 , S 62 . The buyer and seller in this embodiment are not required to settle the transaction with the same account under which they registered with the auction website. For any number of reasons (e.g., amount of funds, newly opened account), the buyer or seller may wish to debit or credit an account separate from the registering account. In the specific embodiment of FIG. 4 , once both the buyer and seller have selected their respective accounts/bills, there are at least two payment scenarios, the first is an immediate transferal of the payment from buyer to seller, the second is a transferal of the payment into an escrow account wherein the money is only transferred to the seller upon the occurrence of certain events (e.g., buyer communicates receipt of good(s) to the financial institution). The methods and systems of the embodiments of the current invention may utilize one or both of these payment scenarios.
[0037] In a first particular embodiment of FIG. 4 , selecting an exemplary amount for illustration purposes, if the final bid price is less than or equal to $500, the first, immediate payment scenario occurs. If the final bid price is greater than $500, the second escrow payment scenario is instituted. Consequently, after the buyer and seller select their respective accounts S 60 , S 62 , the system internally queries the bid price and compares it to the pre-determined threshold of $500 S 64 . If the final bid price is less than or equal to $500 than the buyer's selected account is immediately debited and the seller's selected account is immediately credited S 66 . Both parties are notified immediately via, for example, e-mail, that this transaction has been completed S 68 . The parties will also see the transaction on their monthly statements or on-line if the financial institution offers on-line interim statements for the selected accounts.
[0038] Following the method to FIG. 5 , once the financial portion of the transaction has been completed for a bid price less than or equal to $500, a first time period is set for the seller to deliver the purchased good(s) to the buyer S 80 . The system queries whether or not the seller has delivered the good(s) within the first time period S 82 (e.g., buyer notifies of receipt or lack of receipt). If the seller has not delivered the good(s) within the first time period, the financial institution performs a charge-back or similar transaction, wherein the bid price is taken back from the seller's selected account and credited to the buyer's selected account S 84 . This type of transaction is well known in the financial arts. The auction system may be structured such that the financial institution may charge-back the payment from an alternate account of the seller should the selected account not having the required funds.
[0039] Alternately, if the buyer has received the good(s) within the first time period, a second time period may be set for the buyer to inspect the good(s) to determine if they are conforming S 86 . The system queries whether or not the buyer responds within the second time period S 88 . If there is no response, then the transaction is considered to be complete S 90 . If the buyer does respond within the second time period regarding the good(s), the system queries whether or not the good(s) are in acceptable condition S 92 . If the good(s) are acceptable, the transaction is complete S 94 . If the good(s) are not acceptable, the auction system of the current embodiment offers the buyer one of two choice for completion of the transaction. The buyer may return the good(s) to the seller or the buyer may request a bargaining session with the seller via the auction system S 96 .
[0040] If the buyer chooses to return the good(s), a third time period is set for the buyer to return the good(s) to the seller S 98 . The system queries whether or not the good(s) have been returned within the third time period S 100 . If the good(s) are not returned within the third time period, the transaction is considered to be complete, since the payment has been made to the seller and the buyer presumably has the good(s) S 102 . If the good(s) are returned to the seller within the third time period, a fourth time period is set for the seller to inspect the returned good(s) to make sure they are in the original condition S 104 . The transaction is considered complete if the financial institution does not hear from the seller in the fourth time period or the seller notifies the financial institution that the good(s) are acceptable S 106 . Alternately, if the seller notifies the financial institution within the fourth time period that the good(s) are not acceptable S 108 , the financial institution may refer the seller to legal services to consider the sellers options at his point S 109 . As a service to the client, the financial institution may offer to reimburse the seller for the nonconformance, up to a set amount. The financial institution may also offer insurance for this sort of occurrence at a reasonable price as an option during the registration process.
[0041] Alternately, the buyer may elect to request a bargaining session with the seller due to the fact, for example, that although the good(s) are not in conformance, the buyer wishes to keep the good(s) but at a reduced price S 110 . In this case, a message is sent from the financial institution to the seller, notifying the seller that the good(s) were non-conforming, but that the buyer would like to request a bargaining session with the seller to further discuss the price. At this time, the seller may choose to engage in the bargaining session or the seller may request that the good(s) be returned S 112 . If the seller does not wish to engage in the bargaining session, the buyer may choose to keep the good(s) in which case the transaction is complete or the buyer may return the good(s) to the seller, in which case the steps S 98 -S 109 are applicable.
[0042] Assuming the seller agrees to the bargaining session, referring to FIG. 7 , the buyer is notified of the sellers agreement to participate in a bargaining session and a time period is set within which a new price must be agreed upon or the good(s) must be returned to the seller in order to qualify for a charge-back S 150 . The Internet auction website provides a page for “BARGAINING SESSIONS,” wherein the buyer and seller enter their respective registration IDs into the ID box and they are linked to a page containing the details of their original transaction S 152 . Additionally, a space is provided for a recitation as to the status of the good(s) as received and the reason for the request to lower the initially agreed upon price, as well as a new suggested payment price S 154 . This bargaining session may be limited to x number of messages between buyer and seller, or there may be an unlimited number of messages allowed between the buyer and seller. If the buyer and seller agree on a new price for the good(s), a page is provided to the buyer and seller for submitting the newly agreed upon price S 156 . The financial institution must receive the same price quote from both the buyer and the seller before, in this particular embodiment, a charge-back is performed, debiting the seller's account for the difference between the original bid price and the newly agreed upon price, and crediting the buyer's account for the difference S 168 . In the event that no new price quote is received from both the buyer and seller within the pre-established time period or the buyer does not inform the financial institution that the good(s) have indeed been returned to the seller within the pre-established time period S 158 , the transaction is considered to be complete in this embodiment S 160 . Assuming the good(s) are returned to the seller S 164 , presumably after an unsuccessful bargaining session, steps S 104 -S 109 are followed.
[0043] In a second particular embodiment of FIG. 4 , in the case where the final bid price exceeds $500, the system in this embodiment does not automatically transfer funds from a buyers account to a sellers account. In this embodiment, the buyer has a chance to inspect and accept the good(s) before the seller is credited from the buyer's account or accounts. The bid amount is deducted from the buyer's selected account and entered into an escrow account S 70 . This escrow account may take on various forms, but should be managed such that if the good(s) fail to meet the necessary requirements, the buyer is at the very least reimbursed for the original amount debited from his/her account. There are other management scenarios for the financial institutions escrow account, such as where the buyer actually receives interest back on the principle, in addition to the principle, in the case of non-conforming good(s) from the seller. This escrow account may take on various forms, but should be managed such that if the good(s) fail to meet the necessary requirements, the buyer is at the very least reimbursed for the original amount debited from his/her account. There are other management scenarios for the financial institution's escrow account, such as where the buyer actually receives interest back on the principle, in addition to the principle, in the case of non-conforming good(s) from the seller. This escrow system may be a requirement of the financial institution's Internet auction system, it may be instituted on a transaction by transaction basis (e.g., all transactions over a pre-defined price as in FIG. 4 ), or it may be instituted at the request of either the buyer or seller as a prerequisite to engaging in business with a particular buyer or seller.
[0044] Once the buyer's account or accounts have been debited for the auctioned amount and deposited into the escrow account S 70 , the buyer and seller are notified of this transaction by the financial institution and the seller transfers the purchased good(s) to the buyer through an appropriate medium S 72 . This notification may be through any suitable means, such as e-mail, telephone, or mail, to name a few examples. After notification, the financial institution may start a time period for completion of the transaction (e.g., 5, 10, 15 days). If the seller does not deliver the good(s) within the first time period S 74 , the buyer's payment is returned to the buyer's account S 76 . Alternatively, referring to FIG. 6 , if the buyer has received the good(s) within the first time period, a second time period may be set for the buyer to inspect the good(s) to determine if they are conforming S 120 . The system queries whether or not the buyer responds within the second time period S 122 . If there is no response, then the seller is credited with the buyer's payment from the escrow account S 124 . If the buyer does respond within the second time period regarding the good(s), the system queries whether or not the good(s) are in acceptable condition S 126 . If the good(s) are acceptable, then the seller is credited with the buyer's payment from the escrow account S 128 . If the good(s) are not acceptable, the auction system of the current embodiment offers the buyer one of two choice for completion of the transaction. The buyer may return the good(s) to the seller or the buyer may request a bargaining session with the seller via the auction system S 130 .
[0045] If the buyer chooses to return the good(s), a third time period is set for the buyer to return the good(s) to the seller S 132 . The system queries whether or not the good(s) have been returned within the third time period S 134 . If the good(s) are not returned within the third time period, then the seller is credited with the buyer's payment from the escrow account since the buyer presumably has the good(s) S 136 . If the good(s) are returned to the seller within the third time period, a fourth time period is set for the seller to inspect the returned good(s) to make sure they are in the original condition S 138 . The seller is credited with the buyer's payment from the escrow account if the financial institution does not hear from the seller in the fourth time period or the seller notifies the financial institution that the good(s) are acceptable S 140 . Alternately, if the seller notifies the financial institution within the fourth time period that the good(s) are not acceptable S 142 , the financial institution may refer the seller to legal services to consider the sellers options at his point S 143 . As a service to the client, the financial institution may offer to reimburse the seller for the nonconformance, up to a set amount. The financial institution may also offer insurance for this sort of occurrence at a reasonable price as an option during the registration process.
[0046] Alternately, the buyer may elect to request a bargaining session with the seller due to the fact, for example, that although the good(s) are not in conformance, the buyer wishes to keep the good(s) but at a reduced price S 144 . In this case, a message is sent from the financial institution to the seller, notifying the seller that the good(s) were non-conforming, but that the buyer would like to request a bargaining session with the seller to further discuss the price. At this time, the seller may choose to engage in the bargaining session or the seller may request that the good(s) be returned S 146 . If the seller does not wish to engage in the bargaining session, the buyer may choose to keep the good(s) in which case the seller is credited with the buyer's payment from the escrow account or the buyer may return the good(s) to the seller, in which case the steps S 132 -S 143 may be applicable.
[0047] Assuming the seller agrees to the bargaining session, referring to FIG. 7 , the buyer is notified of the sellers agreement to participate in a bargaining session and a time period is set within which a new price must be agreed upon or the good(s) must be returned to the seller in order to qualify for a charge-back S 150 . The Internet auction website provides a page for “BARGAINING SESSIONS,” wherein the buyer and seller enter their respective registration IDs into the ID box and they are linked to a page containing the details of their original transaction S 152 . Additionally, a space is provided for a recitation as to the status of the good(s) as received and the reason for the request to lower the initially agreed upon price, as well as a new suggested payment price S 154 . This bargaining session may be limited to x number of messages between buyer and seller, or there may be an unlimited number of messages allowed between the buyer and seller. If the buyer and seller agree on a new price for the good(s), a page is provided to the buyer and seller for submitting the newly agreed upon price S 156 . The financial institution must receive the same price quote from both the buyer and the seller before, in this particular embodiment, the seller's account is credited with the new price from the escrow account and the buyer's account is credited from the escrow account for the difference S 170 . In the event that no new price quote is received from both the buyer and seller within the pre-established time period or the buyer does not inform the financial institution that the good(s) have indeed been returned to the seller within the pre-established time period S 158 , the seller's account is credited with the original amount from escrow in this embodiment S 162 . Assuming the good(s) are returned to the seller S 166 , presumably after an unsuccessful bargaining session, steps S 138 -S 143 , respectively, may be followed.
[0048] A further advantage of the preferred embodiment is the ability of the seller to apply the payment from the buyer to any account or bill currently available for payment through the financial institution. For example, many financial institutions offer services, on-line or otherwise, for automatically paying bills for their customer's from the accounts of the customer's managed by the financial institution. In a preferred embodiment of the present invention, the seller may specifically request that the profit from the on-line auction be directed to, for example, their mortgage payment, car loan, student loan, etc. instead of first going to the seller's checking account and then later being debited therefrom to pay these types of bills.
[0049] As discussed with reference to FIG. 3 another aspect of an embodiment of the present invention relates to verification in an Internet auction transaction for a financial account holder who is not a sponsoring financial institution account holder. Such an aspect involves, for example, an arrangement with the certain credit card associations (e.g., Visa®, MasterCard®) or non-sponsoring financial institutions (e.g., Chase, First Union) in connection with authentication of non-sponsoring financial institution account holders. Such non-sponsoring financial institution account holders are allowed to participate in the auction system in an embodiment of the present invention and are allowed to buy on the system and to use their non-sponsoring financial institution accounts to charge the bid price of the good(s). However, non-sponsoring financial institution account holders and/or the non-sponsoring financial institutions or associations may be charged a fee.
[0050] As discussed above, the non-sponsoring financial institutions or associations may become member associations and member financial institutions through arrangements with the sponsoring financial institution. Upon becoming a member association or member financial institution, account holders with these member associations and/or member financial institutions may use the auction website, subject to the registration and verification processes described above.
[0051] In an embodiment of the present invention, for a buyer who is an account holder with a member association and/or member financial institution, the sponsoring financial institution, for example, charges the member association and/or member financial institution account holder for the bid price and issues a check to the seller. Thus, the sponsoring financial institution basically guarantees that the buyer is real, and the sponsoring financial institution looks to the buyer for payment of the money charged on the member association and/or member financial institution account. In other words, the sponsoring financial institution takes the collection risk like it does on any other transaction.
[0052] As part of the verification and settlement proceedings with member associations and/or member financial institutions, the sponsoring institution may check on the available credit of the member association account holders through conventional credit card authorization lines. Further, the sponsoring institution may, for example, check the availability of funds through the pre-established ATM lines, prior to allowing sellers and buyers to register with the Internet auction website. The sponsoring financial institution may also use the ATM lines to check the availability of a buyer's funds at the member financial institution, prior to releasing funds to a seller after a bid price has been reached. The sponsoring financial institution would then release the funds to the seller and begin external settlement proceedings with the member financial institution.
[0053] A further feature of the Internet auction website is the ability of the sponsoring financial institution to track auction performance histories of buyers and sellers who utilize the system. These performance histories include payment and delivery histories of the buyers and sellers as well as purchasing histories of particular buyers and product conformance histories of particular sellers. Using this information, the financial institution may provide information on the reputation of a particular buyer or seller to other prospective buyers and sellers to help facilitate use of the system by trustworthy individuals. Further, by tracking the purchasing habits of buyers, the financial institution may offer as a service to its buyers, notification that certain types of goods have been listed on the auction website. For example, if the financial institution establishes through tracking that a particular buyer frequently purchases antiques, when an antique is listed on the auction website, the financial institution would notify the particular buyer of this new antique listing. This notification could be in the form of, for example, an e-mail, or even a page depending on the arrangement between the buyer and the financial institution.
[0054] Finally, in a similar alternate embodiment, the financial institution may offer a service to potential buyers, wherein the potential buyers specifically request to be alerted when a particular type of good is listed on the website. For example, a potential buyer may be interested in purchasing a computer. The potential buyer requests that the financial institution alert the buyer whenever a computer is listed on the auction website. The alert may be provided through any available media, i.e., e-mail, pager, etc.
[0055] Various preferred embodiments of the invention have been described in fulfillment of the various objects of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.
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There is described a method and system for managing Internet auction transactions by creating an auction website by, for example, a financial institution. The auction website is accessible by the financial institution's account holders (e.g., holders of checking, savings, credit card, and investment accounts). Thus, all buyers and sellers in auction transactions on the auction site, for example, have accounts with the financial institution, with settlements occurring between the accounts of the users at the financial institution. Payments are debited from the buyer's account(s) with a credit going to the account of the seller, less any fees. All charges occur internally, so no interchange is owed, for example, to a card association in connection with a transaction. Financial institution customers benefit from the system in that buyers and sellers are authenticated and settlement occurs almost instantaneously.
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RELATED APPLICATIONS
The present application is based on, and claims priority from, Taiwan Application Number 96147382, filed Dec. 12, 2007 the disclosure of which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a fast locked all digital phase lock loop and control method thereof.
2. Description of the Related Art
All digital phase lock loop (PLL) technology is one of the major technological breakthroughs for wireless communication, because it may be implemented easier in system on chip (SOC) devices manufactured by advanced semiconductor process than the analog phase lock loop. However, designing an all digital PLL with features such as fast locking and low phase noise is challenging.
FIG. 1 is a schematic diagram of a conventional all digital phase lock loop viewed in the phase domain. Following, a digital phase lock loop is briefly introduced. However, for a more detailed description of the digital phase lock loop in FIG. 1 , reference can be made to U.S. Pat. No. 7,145,399.
The phase error φ E between the variable signal f v and reference signal f ref can be determined by the phase detector 115 . As shown in FIG. 1 , the phase detector 115 has three inputs, where one input is provided by inputting the reference signal f ref to the reference phase accumulator 105 and is regarded as the phase of the reference signal f ref . Another input is provided by inputting the variable signal f v to the oscillator phase accumulator 140 and the sampler 145 and is regarded as the phase of the variable signal f v . The last input is the fractional phase error between the variable signal f v and reference signal f ref . The sum of the three inputs is the phase error φ E .
The loop filter 120 filters the phase error φ E and/or adjusts the magnitude of phase error φ E . The loop filter 120 generates an oscillator tuning word (OTW) to modify the output of a digitally controlled oscillator (DCO) 125 , i.e. the variable signal f v .
In the current design of the all digital phase lock loops, gear shift mechanism and type II and higher order loop filters are utilized for achieving the purposes of fast locking and low phase noise. In U.S. Pub. No. 2003/0234693, an all digital phase lock loop is disclosed.
However, designers still must design an adaptive all digital phase lock loop.
BRIEF SUMMARY OF THE INVENTION
An exemplary embodiment consistent with the invention, there is provided an all digital phase lock loop is disclosed, comprising a digitally controlled oscillator, a phase detector, and a loop filter. The digitally controlled oscillator is controlled by an oscillator tuning word to generate a variable signal. The oscillator tuning word comprises a first tuning word and a second tuning word, where the frequency range of the digitally controlled oscillator capable to be adjusted by the second tuning word is broader than that capable to be adjusted by the first tuning word. The phase detector detects a phase error between the variable signal and a reference signal. The phase error is received by the loop filter to output the oscillator tuning word. The loop filter has several stages of the low pass filters and a modification circuit. The modification circuit detects two filter outputs from two low pass filters among the filters and accordingly adjusts the second tuning word.
An exemplary embodiment consistent with the invention, there is provided a control method for a phase lock loop is disclosed, comprising low pass filtering a phase error for several times to generate an oscillator tuning word to control a digitally controlled oscillator, wherein the oscillator tuning word comprises a first tuning word and a second tuning word, and the frequency range of the digitally controlled oscillator, capable to be adjusted by the second tuning word, is broader than that capable to be adjusted by the first tuning word; detecting two filter outputs of a front low pass filter and a back low pass filter; determining whether the two filter outputs meet a predetermined condition; adjusting the second tuning word when the two filter outputs meet the predetermined condition.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1 is a schematic diagram of a conventional all digital phase lock loop viewed in the phase domain.
FIG. 2 is a schematic diagram of an exemplary embodiment of a loop filter 600 consistent with the invention.
FIG. 3 is a schematic diagram of an exemplary embodiment of a decision circuit 700 consistent with the invention
FIG. 4 is a schematic diagram of part of a digitally controlled oscillator 800 .
FIG. 5 is a schematic diagram of another exemplary embodiment of a loop filter 800 consistent with the invention.
FIG. 6 is a flowchart 900 of an exemplary embodiment of a control method for a phase lock loop consistent with the invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments consistent with the present invention do not represent all implementations consistent with the invention. Instead, they are merely examples of systems and methods consistent with aspects related to the invention as recited in the appended claims.
FIG. 2 is a schematic diagram of an exemplary embodiment of a loop filter 600 consistent with the invention. The loop filter 600 receives the phase error φ E and accordingly controls a digitally controlled oscillator. When the loop filter 120 of FIG. 1 is replaced by the loop filter 600 , an all digital phase lock loop consistent with the invention is generated. The loop filter 600 of FIG. 2 outputs an oscillator tuning word comprising a process-voltage-temperature (PVT) tuning word, an acquisition (ACQ) tuning word, and a tracking (ACK) tuning word. For example, the oscillator tuning word output by the loop filter 600 has 22 bits, OTW[ 0 : 21 ], wherein the 8 bits OTW[ 14 : 21 ] is the PVT tuning word, the 8 bits OTW[ 6 : 13 ] is the ACQ tuning word, and the 6 bits OTW[ 0 : 5 ] is the ACK tuning word. The tracking tuning word is generated based on the sum of the output of a multiplier 604 and the accumulated value from an accumulator 608 . The frequency range of the digitally controlled oscillator capable to be adjusted by the PVT tuning word is large and thus accordingly, the adjustment step is also large. The PVT tuning word generally reduces the bad effect due to the Process-Voltage-Temperature variations of the chip. The frequency range of the digitally controlled oscillator capable to be adjusted by the ACK tuning word is small and thus accordingly, the accuracy of adjustment is large. The ACK tuning word is used for calibrating the frequency of the all digital phase lock loop when tracking the carrier signal. The frequency range of the digitally controlled oscillator capable to be adjusted by the ACQ tuning word and corresponding accuracy of adjustment is within the average. The ACQ tuning word is used for calibrating the frequency of the all digital phase lock loop when determining the frequency channel.
The loop filter 600 of FIG. 2 has a plurality of stages of the low pass filters 602 a - 602 c . In FIG. 2 , each low pass filter is an infinite impulse response (IIR) filter or a finite impulse response (FIR) filter. The output of the low pass filter 602 c can be transmitted to a multiplier 604 to be multiplied with a loop gain α. The loop gain α also can be applied to other low pass filters to adjust the filter output of each low pass filter. The phase error φ E can be multiplied with a loop gain β, by a multiplier 606 , and then transmitted to the accumulator 608 . The sum of the multiplier 604 and accumulator 608 generates the tracking tuning word. In a word, the low pass filters 602 a to 602 c and the multiplier 604 forms a type II higher order filter and its time response is slower because the phase error φ E is processed by several stages of the low pass filters and accordingly the tracking tuning word is affected by the phase error φ E . The multiplier 606 and accumulator 608 provide a faster path for the phase error φ E to affect the tracking tuning word.
The loop filter 600 of FIG. 2 further comprises two modification circuits 610 a and 610 b . The modification circuit 610 a has two decision circuits, 6104 a and 6106 a , an accumulator 6102 a and an adder 6108 a . The modification circuit 610 b has two decision circuits, 6104 b and 6106 b , an accumulator 6102 b and an adder 6108 b . Although the function block diagrams of the modification circuits 610 a and 610 b shown in FIG. 2 are the same as each other, the circuits of the same function block may be implemented by different circuits.
The modification circuit 610 a directly detects the outputs of the low pass filters 602 a and 602 b . Once the modification circuit 610 a detects that the outputs of the low pass filters 602 a and 602 b meet a predetermined condition, the modification circuit 610 a modifies the PVT tuning word via the adder 612 . Thus, the frequency of the all digital phase lock loop, i.e. the frequency of the variable signal f v , can be significantly changed.
The modification circuit 610 b directly detects the output of the low pass filter 602 b and indirectly detects the output of the last stage of the low pass filter, i.e. the low pass filter 602 c , via the multiplier 604 and adder 618 . Once the modification circuit 610 b detects that the outputs of the low pass filters 602 b and 602 c meet a predetermined condition, the modification circuit 610 b modifies the ACQ tuning word, wherein the predetermined condition of the modification circuit 610 a may be the same as or different from the predetermined condition of the modification circuit 610 b.
FIG. 3 is a schematic diagram of an exemplary embodiment of a decision circuit 700 consistent with the invention. The decision circuit shown in FIG. 3 can be applied to the decision circuit 6104 a , 6104 b , 6106 a or 6106 b . The comparator 702 compares the input of the decision circuit 700 and a predetermined upper bond (UPB), and the comparator 704 compares the input of the decision circuit 700 and a predetermined lower bond (LWB). The output of the comparator 702 or comparator 704 is 1 or −1, and the sum of the two outputs, by the adder 706 , is the output of the decision circuit 700 . The function of the decision circuit 700 is described in the following. If the input of the decision circuit 700 is higher than the UPB, the output of the decision circuit 700 is 1. If the input of the decision circuit 700 is lower than the LWB, the output of the decision circuit 700 is −1. If the input of the decision circuit 700 is between the LWB and UPB, the output of the decision circuit 700 is 0. If the output of the decision circuit 700 varies acutely, the input of the decision circuit 700 can be multiplied with a parameter λ to decrease the variation of the output of the decision circuit 700 .
Take the modification circuit 610 b in FIG. 2 for example, if the decision circuits 6104 b and 6106 b adopt the decision circuit 700 in FIG. 3 , the UPB and LWB of the decision circuit 6104 b respectively is UPBa and LWBa, and the UPB and LWB of the decision circuit 6106 b respectively is UPBb and LWBb, the function of the modification circuit 610 b is described in the following.
When the phase is approximately locked, i.e., the phase error φ E is very small, the output of the filter 602 b is substantially maintained between UPBa and LWBa, and the output of the filter 602 c is substantially maintained between UPBb and LWBb. Accordingly, the outputs of the decision circuits 6104 b and 6106 b are 0, and the output of the accumulator 6102 b does not change. Thus, the ACQ tuning word is not affected by the output of the accumulator 6102 b.
When the phase error φ E increases, the output of the filter 602 b may diverge from the range between UPBa and LWBa, and the output of the filter 602 c may later diverge from the range between UPBb and LWBb. Since the response of the whole phase lock loop is quite slow, the described two diverging trends are substantially the same. The time delay is because the output of the low pass filter 602 c is generated by low pass filtering the output of the low pass filter 602 b . For example, when the output of the low pass filter 602 b suddenly exceeds UPBa and the output of the low pass filter 602 c is still between the UPBb and LWBb, the output of the decision circuit 6104 b becomes 1 , the output of the decision circuit 6106 b is still 0, and the output of the accumulator 6102 b periodically increases by 1 according to the input clock signal. Thus, the modification circuit 610 b periodically increases the ACQ tuning word by 1. The output of the low pass filter 602 c follows the output of the low pass filter 602 b , but the output of the low pass filter 602 c later varies. Once the output of the low pass filter 602 c is larger than UPBb, the outputs of the decision circuits 6104 b and 6106 b are also 1, the accumulator 6102 b stops increasing its output and the modification circuit 610 b also stops increasing the ACQ tuning word. Similarly, when the outputs of the low pass filters 602 b and 602 c decrease, the modification circuit 610 b may periodically decrease the ACQ tuning word and after a period of time, the modification circuit 610 b stops affecting the ACQ tuning word.
In other words, the modification circuit 610 b determines whether the amount of times the low pass filter 602 b is output is too much according to the UPBa and LWBa. Once the amount of times the low pass filter 602 b is output is too much, the modification circuit 610 b roughly adjusts the output frequency of a digitally controlled oscillator. The UPBa and LWBa serve as a stop mechanism for the modification circuit 610 b . In other words, the UPBa and LWBa determines the amount of frequency adjustments.
According to the above description of the modification circuit 610 b , those skilled in the art can easily understand the operation of the modification circuit 610 a . When the modification circuit 610 a determines that the amount of times the low pass filter 602 a is output is too much, the modification circuit 610 a coarsely adjusts the output frequency of a digitally controlled oscillator. The UPBa and LWBa serve as a stop mechanism for the modification circuit 610 a . In other words, the UPBa and LWBa determines the amount of frequency adjustments.
As to the UPB and LWB of each decision circuit, the UPB and LWB are respectively determined based on circuit design or requirement.
The modification circuits 610 a and 610 b quickly and coarsely adjust the output frequency of a digitally controlled oscillator. Without the modification circuits 610 a and 610 b in FIG. 2 , the PVT tuning word can only be affected by the carry bit of the ACQ tuning word, and the ACQ tuning word only can be affected by the carry bit of the ACK tuning word. Thus, the PVT tuning word and the ACQ tuning can only be increased by 1 after each phase lock operation. Compared with FIG. 2 , the modification circuits 610 a and 610 b provide a mechanism for quickly and coarsely adjusting the output frequency of the digitally controlled oscillator by a large margin. It can be expected that an all digital phase lock loop with the loop filter 600 in FIG. 2 can lock its phase quickly.
Although the loop filter 600 in FIG. 2 is shown by a functional block, the loop filter 600 can be implemented by hardware or software.
FIG. 4 is a schematic diagram of part of a digitally controlled oscillator 800 . The digitally controlled oscillator 800 comprises one inductor and a plurality of capacitors, and its output frequency is determined by the following equation: f DCO =1/squr(L*C total ), wherein the C total is the sum of the capacitances of activated capacitors. The capacitors in the digitally controlled oscillator 800 are substantially divided into four banks: a PVT bank, an ACQ bank, a tracking bank and a partial tracking bank. The capacitors in the PVT bank are Δ C 0 P . . . ΔC 7 P , arranged binary-weighted, respectively selected by the control signal d 0 P . . . d 7 P . The PVT tuning word is applied to some interfaces and the control signal is generated after the PVT tuning word is processed by the interfaces. In other word, the capacitors in the PVT bank are controlled by the PVT tuning word. Similarly, the capacitors in the ACQ bank are controlled by the ACQ tuning word. The capacitors in the tracking band are the same (unit-weighted) and the capacitance of each capacitor is designed as small as possible. The signals d 0 TI . . . d 63 TI are generated after the tracking tuning word is decoded and processed by some interface. If the capacitance provided by the tracking bank cannot effectively suppress the phase noise, the capacitors in the partial tracking bank can be initiated to provide capacitance. The capacitance of each capacitor in the partial tracking bank is the same as the capacitor in the tracking bank. The partial tracking bank is controlled by a ΣΔ modulator to provide fine capacitance accuracy and the control signal d 0 TF . . . d 7 TF is generated by the ΣΔ modulator. Basically, the tracking bank and the partial tracking bank are controlled by the tracking tuning word. As previously described, the PVT tuning word coarsely adjusts the output frequency of the digitally controlled oscillator. The tracking finely adjusts tuning of the output frequency of the digitally controlled oscillator and the ACQ tuning word averagely adjusts the output frequency of the digitally controlled oscillator. Therefore, the smallest capacitor in the PVT bank is larger than the smallest capacitor in the ACQ bank and the smallest capacitor in the ACQ bank is larger than each capacitor in the tracking bank and the partial tracking bank.
Please refer to FIG. 2 , wherein the modification circuit 610 a is coupled to the low pass filter 602 a and the low pass filter 602 b , the low pass filter 602 a is a front low pass filter, and the low pass filter 602 b is a back low pass filter to process the filter output of the low pass filter 602 a . Similarly, the modification circuit 610 b is coupled to the low pass filter 602 b and the low pass filter 602 c , the low pass filter 602 b is a front low pass filter, and the low pass filter 602 c is a back low pass filter. Thus, the low pass filter 602 b is the back low pass filter detected by the modification circuit 610 a and the front low pass filter detected by the modification circuit 610 b . However, it is not necessary that the modification circuits 610 a and 610 b detect the same low pass filter. FIG. 5 is a schematic diagram of another exemplary embodiment of a loop filter 800 consistent with the invention, wherein the modification circuits 610 a and 610 b do not detect the same low pass filter.
Please also refer to FIG. 2 and FIG. 6 for reference. FIG. 6 is a flowchart 900 of an exemplary embodiment of a control method for a phase lock loop consistent with the invention. When an all digital phase lock loop with the loop filter 600 shown in FIG. 2 starts tracking a reference signal, the coarse tracking in the step 902 is first executed, and after a period of time, the fast tracking in the step 904 is executed.
In the step 902 , the modification circuits 610 a and 610 b are enabled, and the loop gain α and partial gain β do not change. Thus, the ACQ tuning word may be slightly affected by the carry bit of the tracking tuning word, and may be heavily affected by the modification circuit 610 b . Similarly, the PVT tuning word may be slightly affected by the carry bit of the ACQ tuning word, and may be heavily affected by the modification circuit 610 a.
After a period of time or when the coarse tuning has been substantially finished, the values of the accumulators 6102 a and 6102 b are substantially fixed and the method goes to the step 904 . In step 904 , the modification circuits 610 a and 610 b are disabled, and the loop gain a and partial gain β can be first increased and then decreased after a period of time. In other words, when executing the step 904 , the loop gain a and partial gain β can be the same as the loop gain α and partial gain β in step 902 for a period of time. After that, the phase lock operation is substantially finished, and in order to reduce the noise caused by the phase lock loop, a smaller loop gain α and partial gain β are adopted. The operation for reducing the loop gain α and partial gain β can be implemented at more than one time according to the circuit design and the phase lock speed requirement. It is recommended that the operation of reducing the loop gain α and partial gain β be executed at least two times.
An all digital phase lock loop with higher order loop filters consistent with the invention is provided. The disclosed all digital phase lock loop can reduce the phase noise that is self generated and coarsely and quickly adjust its output frequency to achieve the goal of fast phase lock.
It will be appreciated that the present invention is not limited to the exact construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof. It is intended that the scope of the invention only be limited by the appended claims.
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An all digital phase lock loop is disclosed, including a digitally controlled oscillator, a phase detector, and a loop filter. The digitally controlled oscillator is controlled by an oscillator tuning word to generate a variable signal. The oscillator tuning word includes a first tuning word and a second tuning word, where the frequency range of the digitally controlled oscillator, capable to be adjusted by the second tuning word, is broader than that capable to be adjusted by the first tuning word. The phase detector detects a phase error between the variable signal and a reference signal. The phase error is received by the loop filter to output the oscillator tuning word. The loop filter has several stages of the low pass filters and a modification circuit. The modification circuit detects two filter outputs from two low pass filters among the filters and accordingly adjusts the second tuning word.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 14/414,338, filed Jan. 12, 2015, which is a 371 of International Application No. PCT/EP2013/064785, filed Jul. 12, 2013, which claims the benefit of U.S. Provisional Application No. 61/671,343, filed Jul. 13, 2012, the disclosures of which are fully incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention relates to the field of Connectivity Fault Management in a communications network, in particular a network that supports Equal Cost Multiple Paths.
BACKGROUND
[0003] Operations, Administration and Maintenance (OAM) is a term used to describe processes, activities, tools, standards and so on that are involved with operating, administering, managing and maintaining a communication network. OAM requires fault management and performance monitoring, connectivity fault management and link layer discovery.
[0004] CFM is a protocol of OAM that provides Connectivity Fault Management (CFM). The CFM protocol uses Maintenance Domains (MD) for monitoring levels of service providers, core networks or system operators. Each level has Maintenance Associations (MA) dedicated to monitoring specific provider/provider or provider/customer service. Each MA depends on a set of Maintenance Points (MPs) for monitoring. An MA is established to verify the integrity of a single service instance. A Maintenance Association Edge Point (MEP) is an actively managed CFM entity which provides the extent of an MA and is associated with a specific port of a service instance. It can generate and receive CFM Protocol Data Units (PDUs) and track any responses. It is an end point of a single MA, and is an endpoint for each of the other MEPs in the same MA.
[0005] CFM PDUs are transmitted by a MEP in order to monitor the service to which the transmitting MEP belongs. A problem arises in Equal-Cost Multiple Paths routing (ECMP) networks where CFMs cannot be guaranteed to take the same path as the data.
[0006] ECMP routing is a forwarding mechanism for routing packets along multiple paths of equal cost. An aim of ECMP is to equalise distributed link load sharing. Referring to FIG. 1 , there is illustrated schematically a very simple network architecture in which data sent between two endpoints 1 , 2 can be sent via intermediate nodes 3 or 4 at equal cost. Some data packets are sent via intermediate node 3 and others are sent via intermediate node 4 . In this way the load on the network is balanced.
[0007] Shortest Path Bridging (SPB) enables the use of link state protocols (IS-IS) for constructing active topologies within a Bridged Network. For more information, see IEEE Std 802.1aq-2012, Shortest Path Bridging. Recent standardization work within IEEE802.1 enhances SPB by enabling ECMP support on SPBM services that use the same VID identifier, as described in P802.1Qbp/D1.0 Equal Cost Multiple Path (ECMP). P802.1Qbp discusses the services supporting ECMP connectivity and, in particular, defines two types of ECMP connectivity. One is associated with point-to-point (PtP) ECMP services provided by ECMP devices that support flow filtering. The other is a generic Virtual LAN (VLAN) service associated with a specific VLAN Identifier (VID) that is mapped to ECMP operation (SPBM VLAN MA in clause 27.18.1 in P802.1Qbp/D1.0 Equal Cost Multiple Path).
[0008] ECMP connectivity paths may use the same Bridging VLAN Identifier (B-VID) in their tags but the service connectivity provided by these paths are different than that associated with frames having the same B-VID and controlled by traditional L2 control protocols like spanning tree or SPB . A typical example of connectivity instances that use the same VID but are not members of a VLAN are Traffic Engineered Service Instances (TESIs) in Provider Backbone Bridges-Traffic Engineering (PBB-TE). ECMP connectivity is similar to that of TESIs but it has a further property that a superset of all ECMP paths identified by the same VID (and endpoints) is not a tree topology. A VLAN on the other hand is always defined in a context of a tree (see clause 7 in IEEE Std 802.1Q-2011, VLAN aware Bridges).
[0009] Shortest Path Bridging—MAC address mode (SPBM) connectivity is different to ECMP connectivity. SPBM connectivity is similar to that of PBB-TE (in that it there is no flooding, no learning, it is symmetric, and uses only explicit entries in a Filtering Database (FDB) for forwarding), which means in practice that CFM enhancements for PBB-TE (described in IEEE Std 802.1Qay-2009 PBB-TE and IEEE Std 802.1Q-2011, VLAN aware Bridges) can be used almost identically for SPBM MAs. Nevertheless, ECMP connectivity differs in that multiple paths are enabled for the same end points. The same VID and correspondingly the ECMP CFM require further changes in order to monitor the associated services. As a result ECMP MAs need to be separated from SPBM MAs, and the associated monitoring protocol tools need to be modified as their operation depends on the type of connectivity that they monitor.
[0010] ECMP Point-to-Point (PtP) path connectivity and the associated monitoring tools are described in P802.1Qbp, but P802.1Qbp does not describe ECMP multipoint monitoring in a consistent manner. In particular, the “SPBM VLAN” connectivity is associated with an overall connectivity identified by the same SPBM VID value. However, an overall SPBM-VID connectivity is meaningless for ECMP, because ECMP creates multiple independent connectivity paths between subsets of nodes that are members of the SPBM-VID. The operational status of each of the ECMP subsets is therefore independent of the operational status of the other ECMP subsets identified by the same SPBM-VID. This ECMP independency means that, when using SPBM OAM mechanisms and an overall SPBM-VID connectivity is reported as being error-free, the connectivity on ECMP subsets could be non-operational. The above connectivity characteristic of the SPBM VLAN Maintenance Association (MA) creates problems for monitoring multipoint ECMP services. In particular, since the SPBM VLAN Continuity Check protocol attempts to monitor the overall “VLAN” service, the scope of propagation of the Continuity Check Message (CCM) PDUs is provided by the use of a broadcast address (constructed using SPBM default Backbone Service Identifier, I-SID). The result of this is that monitored connectivity is different from the connectivity associated with the monitored data traffic. In addition, the operation of Link Trace Messages (LTM) becomes quite difficult and the extent of reachability of the LTMs can be quite different to that defined by the configured ECMP related MAC address entries.
[0011] Furthermore, the placement of the “SPBM VLAN MEP” in parallel to ECMP PtP path Maintenance Association Edge Points (MEPs) breaks the operation of the ECMP path MAs (stopping every ECMP Path CFM PDU on the SPBM-VID as can be seen from FIG. 27-4 in P802.1Qbp/D1.0.)
SUMMARY
[0012] It is an object to provide a mechanism by which Connectivity Fault Management Maintenance Associations can be monitored in an Equal Cost Multiple Paths network.
[0013] According to a first aspect, there is provided a method of monitoring a Maintenance Association (MA) for Connectivity Fault Management (CFM) in a network supporting Equal Cost Multiple Paths (ECMP). A set of ECMP paths is generated for sending data between endpoints in the network. Furthermore, a set of ECMP MAs is created that are used for monitoring the generated ECMP paths between the endpoints. The created set of ECMP MAs is subsequently used for sending monitoring packets. An advantage of this is that ECMP paths MAs conform to existing CFM operation and are compatible with both ECMP point to point path MAs and ECMP multipoint path MAs.
[0014] As an option, each monitoring packet comprises a CFM Protocol Data Unit. An advantage is that the forwarding parameters of the PDU are the same as those for monitored data packets sent using the ECMP paths, and so the monitoring packets will traverse the same path.
[0015] As an option, the method includes generating the set of ECMP paths using ECMP Point to Point paths, wherein the Point to Point paths comprising a set of equal shortest length connectivity paths between the two end points.
[0016] As an alternative option, the method includes generating the set of ECMP paths using ECMP multipoint paths. The multipoint paths include a set of connectivity multipoint paths among the same end points. As a further option, each ECMP path comprises an ECMP multipoint path having N endpoints. Each ECMP multipoint path may be identified using a Group address. As a further option, each ECMP multipoint path associated with the two end points may be identified using a Group MAC address. In this case, the Group MAC address is optionally constructed by applying an operation on Backbone Service Identifier values associated with the ECMP multipoint paths.
[0017] As an option, the method further includes monitoring an ECMP path by sending the monitored packet using the identifier associated with the specific path. Optional examples of such an identifier are a Flow Hash and a Group MAC address identifying the path.
[0018] As an alternative option, the method further includes monitoring a plurality of ECMP paths by sending monitored packets in groups cyclically on each monitored ECMP path, using the identifier associated with each monitored ECMP path.
[0019] According to a second aspect, there is provided a node for use in a communications network supporting ECMP. The node is provided with a processor for generating a set of ECMP path MAs for sending data between end points. The processor is further arranged to create a set of ECMP MAs for monitoring the generated ECMP paths between the endpoints. A transmitter is also provided for sending monitoring packets using the set of generated ECMP paths. An advantage of this is that ECMP paths MAs conform to existing CFM operations, and are compatible with both ECMP point to point path MAs and ECMP multipoint path MAs. The node is optionally implemented in any type of device that implements ECMP.
[0020] As an option, the node is provided with a computer readable medium in the form of a memory for storing information mapping at least one Service Identifier to each generated ECMP path.
[0021] The processor is optionally arranged to generate monitoring packets using ECMP Point to Point paths comprising a set of equal shortest length connectivity paths between the end points.
[0022] As an alternative option, the processor is arranged to generate monitoring packets using ECMP multipoint paths comprising a set of connectivity multipoint paths among a plurality of end points. As a further option, the processor is arranged to identify an ECMP multipoint path monitoring packet using a Group MAC address for each ECMP path. In this case, the processor is optionally arranged to construct each Group MAC address by applying an operation on Backbone Service Identifier values associated with the ECMP multipoint paths.
[0023] According to a third aspect, there is provided a computer program comprising computer readable code which, when run on a node, causes the node to perform the method as described above in the first aspect.
[0024] According to a fourth aspect, there is provided a computer program product comprising a non-transitory computer readable medium and a computer program described above in the third aspect, wherein the computer program is stored on the computer readable medium.
[0025] According to a fifth aspect, there is provided a vessel or vehicle comprising the node described above in the second aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 illustrates schematically in a block diagram a network architecture showing the principles of Equal Cost Multiple Path routing:
[0027] FIG. 2 is a flow diagram showing steps according to an embodiment;
[0028] FIG. 3 illustrates schematically in a block diagram an exemplary node; and
[0029] FIG. 4 illustrates schematically in a block diagram an exemplary vessel or vehicle.
DETAILED DESCRIPTION
[0030] A consistent way of enabling OAM monitoring for Connectivity Fault Management for both ECMP PtP path MAs and ECMP Multipoint path MAs is provided. “Fate sharing” is guaranteed by using the same forwarding parameters for monitoring packets such as CFM PDUs monitoring the ECMP service as for monitored data frames. In particular, the destination address of CFM PDUs associated with ECMP path MAs is the same address used to reach remote MEPs within the same MA, and is provided by the configuration of the MA itself. Each specific ECMP is identified by a Flow Hash value and any subsets of ECMP paths within the same PtP path are identified by the associated subset of Flow Hash values.
[0031] An ECMP path MA is associated with a connectivity path connecting a specific group of endpoints or with a subset (not necessarily proper) of equal cost paths connecting the same end points. In the latter case, the corresponding CFM PDUs are sent in groups cyclically on every monitored path, using an identifier associated with every monitored path. The number of CFM PDUs in every group depends on the specific CFM PDU: For example, for CCMs, at least four CCMs must be sent on a single monitored path before moving to the next one. For Loopback Messages (LBMs), as many LBMs as provided by the administrator that initiates the LBM are sent. Only one LTM need be sent. This is because CCMs are sent periodically, and a fault is only reported when more than three consecutive CCMs are in error (so we need to send at least four on the same path to be able to check it). The periodicity of LBMs (if any) is configurable and correspondingly the number of LBMs on individual paths must be based on the configuration setting. LTMs are set to identify individual nodes along the path, and so only one LTM on each individual path is required.
[0032] In the case of ECMP multipoint path services, the destination_address parameter of the associated monitoring CFM PDUs is set cyclically to the SPBM Group MAC address associated with the monitored multipoint service. SPBM Group MAC address assignment can be automated.
[0033] In more detail, two ECMP connectivity paths are defined as follows:
[0034] 1. ECMP PtP path: This is the complete set of equal shortest length connectivity paths between two specific end points as constructed by ECMP. In addition to what is described in P802.1Qbp/1.0, LB and LT use the same cyclic methods when a subset of Flow Hash values is provided.
[0035] 2. ECMP multipoint path: This is the complete set of connectivity multipoint paths among more than two end points as constructed by ECMP. A single multipoint path within an ECMP multipoint path of N endpoints is identified either by:
[0036] (a). N Group MAC addresses constructed as follows: the first 3 bytes corresponding to the SPsourceID of the initiating Backbone Edge Bridge (BEB) and the last 3 bytes corresponding to the same I-SID identifying the N endpoint connectivity (this I-SID value may be automated to, for example, be the least backbone I-SID value on the set of I-SID values mapped to an ECMP-VID operation within the Backbone Service Instance table on the terminating BEBs having the least SPsourceID), that is: (SPsourceID[1]-ISID, SPsourceID[2]-ISID, . . . , SPsourceID[N]-ISID); or (b). A single Group MAC address for all endpoints constructed as follows: the first 3 bytes corresponding to the IEEE 802.1Q Backbone Service Instance Group address OUI (see clause 26.4 in IEEE Std 802.1Q-2011, VLAN aware Bridges) and the last three bytes corresponding to the same I-SID identifying the N endpoint connectivity (this I-SID value chosen could be automated to, for example, be the least backbone I-SID value on the set of I-SID values mapped to an ECMP-VID operation within the Backbone Service Instance table on the terminating BEBs having the least SPsourceID). That is the same group address that is used for all I-SID endpoints corresponding to the Backbone Service instance Group Address.
[0037] The choice between (a) and (b) type of addressing described above is made by configuration. Note that the selection of (a) or (b) depends on how the ECMP multipoint connectivity is set up. Option (a) requires the set up N individual MAC addresses for an N point connectivity, while option (b) requires a single MAC address for an N-point connectivity. Option (a) provides better coverage at the expense of increased complexity.
[0038] Other multipoint paths (up to 16 for each group, a or b) within the same ECMP multipoint connectivity associated with exactly the same N endpoints can be identified by using Group MAC addresses constructed by the above sets by x:oring the I-SID values in (a) or (b) type addressing using tie break masks described in 28.8 in IEEE Std 802.1aq-2012, Shortest Path Bridging.
[0039] In order to enable ECMP operation, an I-SID to path mapping table must be configured for all local I-SIDs that map to the B-VID indicating ECMP operation on the BEBs Backbone Service Instance table. Note that there may be a default configuration set to distribute I-SIDs equally to all ECMP paths. In this case, I-SIDs can be mapped in increasing order to paths. Table 1 below is an example of such a table:
[0000]
TABLE 1
Exemplary mapping of I-SIDs to paths.
I-SID 1 , I-SID 2 , . . . , I-SID k
Path 1
I-SID k+1 , . . . , I-SID k+m
Path 2
I-SID p , . . . , I-SID z
Path 16
[0040] For each subset of I-SID values that are mapped on the same path, the least I-SID low value is identified and all the subsets are ordered on increasing I-SID low values. The I-SID subsets are then mapped to multipoint paths identified by Group MAC addresses constructed as defined above and x:ored in accordance with IEEE std 802.1aq-2012 in increasing order. Table 2 illustrates an I-SID distribution table when addressing method (a) is used:
[0000]
TABLE 2
Exemplary mapping of I-SIDs to paths
1000, 40000, 3443
Path 1
999, 104000
Path 2
39000, 1010
Path 3
800000, 995
Path 4
[0041] An exemplary automated constructed Group MAC for a node identified by SPSourceID 5 (having the appropriate multicast address bit set) is shown in Table 3.
[0000]
TABLE 3
Exemplary automated constructed Group MAC
800000, 995
5-995
999, 104000
5-(995 x:ored 0x01)
1000, 40000, 3443
5-(995 x:ored 0x02)
39000, 1010
5-(995 x:ored 0x03)
[0042] The method described above provides a way to automate the allocation of identifiers of individual paths within ECMP multipoint path connectivity.
[0043] The address used by CFM PDUs to reach remote MEPs within the same ECMP path MA is provided by the configuration of the MA itself. In the case of the ECMP multipoint path MAs it is an SPBM Group Address associated with the monitored service. The above method describes a way to automate the distribution of Group addresses based on the I-SID ECMP configuration tables. In the case of a single path with the ECMP path MA, the CFM PDUs use the MAC address associated with it. In cases where more then one path is monitored, the CFM PDUs are cyclically destined to the associated Group MAC addresses.
[0044] The associated ECMP path MEPs are placed on a Customer Backbone Port (CBP) by using the TESI multiplex entities and using the associated Group MAC address identifiers
[0045] The techniques described above enable automated configuration of ECMP multipoint path MAs in a way that does not require alterations to existing CFM operations, and is compatible with ECMP PtP paths MAs.
[0046] Turning now to FIG. 2 , there is shown a flow diagram showing steps of an exemplary embodiment. The following numbering corresponds to that of FIG. 2 .
[0047] S 1 . ECMP multipoint paths are generated and are identified by a set of SPB Group Addresses as described above.
[0048] S 2 . ECMP PtP and multipoint path MAs are determined in order to monitor the ECMP paths. The ECMP path MAs can be associated with a connectivity path connecting a specific group of endpoints or with a subset (not necessarily proper) of equal cost paths connecting the same end points. Each ECMP PtP individual path is identified by a Flow Hash value, while each ECMP multipoint individual path is identified by an SPB Group Address as described above.
[0049] S 3 . CFM PDUs are sent and processed on those MAs determined in step S 2 . When multiple paths are used, the corresponding CFM PDUs are sent in groups cyclically on every monitored path, using the identifier associated with every monitored path. The number of CFM PDUs in every group depends on the specific CFM PDU. For example, for CCMs there should be sent at least 4 CCMs on a single monitored path before moving to the next one. For LBMs, as many LBMs as provided by the administrator that initiated the LBM are sent. For LTMs, only one LTM is sent.
[0050] As described above, there are various ways in which I-SID subsets that define paths can be mapped to Group MAC addresses.
[0051] Turning now to FIG. 3 , there is illustrated a node 5 for use in a communications network. Examples of implementations of the node 5 are any types of device that implement ECMP. This includes a VLAN aware bridge that implements IS-IS SPB and all the ECMP related functionality as described by P802.1Qbp. The node 5 may also be implemented in any device (virtual or physical), such as a router or a virtual machine, that implements the ECMP related functionality as described in P802.1Qbp.
[0052] The node 5 is provided with a processor 6 for generating the ECMP paths and applying them to data and CFM PDUs. A transmitter 7 and receiver 8 may also be provided. Note that this may be in the form of a separate transmitter and receiver or in the form of a transceiver. A non-transitory computer readable medium in the form of a memory 9 may be provided. This may be used to store a program 10 which, when executed by the processor 6 , causes the node 5 to behave as described above. The memory 9 may also be used to store tables 11 , such as Tables 1 to 3 described above for mapping I-SID values and Group MAC addresses to paths. Note that the memory 9 may be a single physical memory or may be distributed or connected remotely to the node 5 . In the example of FIG. 2 , the memory is shown as being located at the node 5 .
[0053] Note also that the computer program 10 may be provided on a further non-transitory computer readable medium 12 such as a Compact Disk or flash drive and transferred from the further memory 12 to the memory 9 or executed by the processor 6 directly from the further memory 12 .
[0054] A node such as a Bridge network node supporting ECMP can typically support a plurality of other service types (such as VLAN, Traffic Engineered services, Backbone tunnel services, etc). In an embodiment, the network is a Provider Backbone network where its edges (the endpoints described above) are Backbone Edge Bridges (which can encapsulate and decapsulate received frames) while transit Bridges are called Backbone Core Bridges which do not have encapsulation/decapsulation capabilities. The network needs to run Shortest Path Bridging in MAC mode (SPBM) which is used to create shortest paths between the edges. ECMP further updates SPBM in order to enable multiple paths among the same edges. A node performing ECMP typically has processing capabilities and requirements associated with the ECMP service monitoring. That is, ECMP MEPs need to be instantiated at the BEBs (in particular CBPs (Customer Backbone Ports within the BEBs) in order to initiate and process CFM PDUs associated with the ECMP services, and ECMP MIPs need to be instantiated at BCBs in order to process received CFM PDUs and respond.
[0055] Turning to FIG. 4 herein, there is illustrated a vessel or vehicle 13 , examples of which include a ship, a train, a truck, a car, an aeroplane and so on. The vessel/vehicle 13 is provided with the node 5 described above.
[0056] It will be appreciated by the person of skill in the art that various modifications may be made to the above described embodiments. For example, the functions of the network node are described as being embodied at a single node, but it will be appreciated that different functions may be provided at different network nodes.
[0057] The following abbreviations have been used in this specification:
[0058] BEB Backbone Edge Bridge
[0059] B-VID Bridging VLAN Identifier
[0060] CBP Customer Backbone Port
[0061] CCM Continuity Check Message
[0062] CFM Connectivity Fault Management
[0063] ECMP Equal Cost Multiple Paths
[0064] FDB Filtering Database
[0065] IS-IS Intermediate System to Intermediate System
[0066] I-SID Backbone Service Identifier
[0067] LBM Loopback Message
[0068] LTM Link Trace Message
[0069] MA Maintenance Association
[0070] MEP Maintenance Association Edge Point
[0071] OAM Operations, Administration and Maintenance
[0072] PBB-TE Provider Backbone Bridges—Traffic Engineering
[0073] PDU Protocol Data Unit
[0074] PtP Point to point
[0075] SPB Shortest Path Bridging
[0076] SPBM Shortest Path Bridging—MAC address mode
[0077] TESI Traffic Engineered Service Instance
[0078] VID VLAN Identifier
[0079] VLAN Virtual LAN
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Methods and apparatus are disclosed for monitoring a Maintenance Association (MA) for Connectivity Fault Management (CFM) in a network supporting Equal Cost Multiple Paths (ECMP). A set of ECMP paths is generated for sending data between endpoints in the network. Furthermore, a set of ECMP MAs is created that are used for monitoring the generated ECMP paths between the endpoints. The created set of ECMP MAs is subsequently used for sending monitoring packets. ECMP path MAs therefore conform to existing CFM operation and are compatible with both ECMP point to point path MAs and ECMP multipoint path MAs.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the National Stage of International Application No. PCT/EP2011/053027, filed on Mar. 1, 2011, which claims the benefit of the priority date of French Application No. 1051544, filed on Mar. 3, 2010. The content of these applications is hereby incorporated by reference in its entirety.
FIELD OF DISCLOSURE
The invention pertains to a radiofrequency oscillator and to a method for generating an oscillating signal with this radiofrequency oscillator,
Radiofrequency oscillators integrate a magnetoresistive device within which a spin-polarized electrical current flows. In such an oscillator, the passage of the current prompts a periodic variation in the resistance of the magnetoresistive device. A high-frequency signal, i.e. a signal whose frequency typically ranges from 100 MHz to some tens of GHz, is built from this periodic variation. The period of the variations of the resistivity, and therefore the oscillation frequency, can be adjusted by playing on the intensity of the current that crosses the magnetoresistive device and/or an external magnetic field.
BACKGROUND
Such oscillators are intended for example for use in radio telecommunications because they can generate a wide range of frequencies with a high quality factor.
The term “quality factor” designates the following ratio:
Q=f osc /Δf
Where:
Q is the quality factor, f osc is the oscillation frequency of the oscillator, and Δf is the width at mid-height of the line centered on the frequency f osc in the power spectrum of this oscillator.
Certain radiofrequency oscillators are derived from spin electronics.
Spin electronics uses the spin of the electrons as an additional degree of freedom in order to generate novel effects. The spin polarization of an electrical current results from the asymmetry existing between the diffusion of the spin-up type conduction electrons (i.e. electrons parallel to the local magnetization) and spin-down type conduction electrons (i.e. electrons anti-parallel to the local magnetization). This asymmetry leads to an asymmetry in the conductivity between the two spin-up and spin-down channels, whence a sharp spin polarization of the electrical current.
This spin polarization of the current is the source of magnetoresistive phenomena in magnetic multi-layers such as giant magnetoresistance (Baibich, M., Broto, J. M., Fert, A., Nguyen Van Dau, F., Petroff, F., Etienne, P., Creuzet, G., Fnederch, A. and Chazelas, J., “ Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices”, Phys. Rev. Lett., 61 (1988) 2472), or tunnel magnetoresistance (Moodera, J S., Kinder, L R., Wong, T M. and Meservey, R. “ Large magnetoresistance at room temperature in ferromagnetic thin - film tunnel junctions ”, Phys. Rev. Lett 74, (1995) 3273-6).
Besides, it has also been observed that passing a spin-polarized current through a thin magnetic layer can induce a reversal of its magnetization when there is no external magnetic field (Katine, J. A., Albert, F. J., Buhrman, R. A., Myers, E. B., and Ralph, D. C., “ Current - Driven Magnetization Reversal and Spin - Wave Excitations in Co/Cu/Co Pillars ”, Phys. Rev. Lett. 84, 3149 (2000).
Polarized current can also generate sustained magnetic excitations, also known as oscillations (Kiselev, S I., Sankey, J. C., Krivorotov, Emley, N. C., Schoelkopf, R. J., Buhrman, R. A., and Ralph, D. C., “ Microwave oscillations of a nanomagnet driven by a spin - polarized current ”, Nature, 425, 380 (2003)). By using the effect of the generation of sustained magnetic excitations on a magnetoresistive device it is possible to convert this effect into a modulation of electrical resistance that is directly usable in electronic circuits and that can therefore, as a corollary, act directly at the frequency level. The U.S. Pat. No. 5,695,864 describes various developments implementing the physical principle mentioned here above. It describes especially the precession of the magnetization of a magnetic layer through which a spin-polarized electrical current flows. The physical principles implemented as well as the terminology used are also described and defined in the patent application number FR 2 892 871.
The oscillation frequency of these radiofrequency oscillators is adjusted by playing on the intensity of the current that crosses it and, if necessary, also on an external magnetic field.
Prior-art radiofrequency oscillators comprise:
a magnetoresistive device within which there flows a spin-polarized electrical current to generate a signal oscillating at an oscillation frequency on an output terminal, this device comprising a stack of at least: a first magnetic layer, called a “reference layer”, capable of spin-polarizing the electrical current, and having a magnetization of fixed direction, a second magnetic layer, called a “free layer”, the magnetization of which can oscillate when it is crossed by the spin-polarized current, and a non-magnetic layer, called a “spacer” interposed between the two previous layers to form a tunnel junction or a spin valve, a current source to make a current of electrons flow in said layers perpendicularly to them, a control terminal to control the frequency or amplitude of the oscillating signal. a feedback loop connected between the output terminal and the control terminal.
The spacer forms a tunnel junction when it is designed to create the phenomenon of tunnel magnetoresistance. As a variant, the spacer forms a spin valve when it is designed to create the phenomenon of giant magnetoresistance.
Prior-art oscillators work well but several improvements are desirable. For example, it is desirable to improve the quality factor of these radiofrequency oscillators. It is also desirable to reduce their consumption of electricity.
SUMMARY
The invention seeks to improve prior-art radiofrequency oscillators on at least one of these points,
An object of the invention therefore is a radiofrequency oscillator in which the feedback loop comprises an amplifier equipped with:
an input connected to the output terminal so as to amplify the part of the oscillating signal picked up at the output terminal, and an output connected to the control terminal so as to inject, into this control terminal, an amplified part of the oscillating signal in phase with the oscillating signal generated at the output terminal.
Reinjecting an amplified part of the oscillating signal into the control terminal improves the quality factor of the oscillator.
The embodiments of this oscillator may comprise one or ore of the following characteristics:
the current source is capable only of generating a direct current, the intensity of which is below the threshold beyond which the sustained precession of magnetization of the free layer appears; the gain of the amplifier is sufficient to compensate for the losses f the magnetoresistive device; the input and the output of the amplifier are directly connected, respectively, to the output terminal of the magnetoresistive device and to the control terminal; the spacer is an electrically insulating material disposed so as to create a tunnel junction, the RA factor of which is greater than 2 or 5 Ωμm 2 ; the oscillator comprises a generator of a magnetic field, the field lines of which pass through the free layer, this generator being equipped with a control terminal for controlling at least one characteristic of the generated magnetic field capable of modifying the oscillation frequency of the magnetoresistive device, this control terminal constituting the terminal for controlling the frequency or the amplitude of the oscillating signal.
These embodiments of the oscillator furthermore have the following advantages:
using a magnetoresistive device, the intensity of the current of which remains below the critical current, limits current consumption and enables the use of more sensitive magnetoresistive devices; using a feedback loop directly connected between the output terminal and the control terminal gives a very short feedback loop that introduces almost no phase delay and therefore averts the use of a phase-shifter. using a magnetoresistive device for which the product RA is greater than 2 or 5 Ωμm 2 increases the amplitude of the oscillating signal; using a magnetic field to control the frequency or amplitude of the oscillating signal decreases the electrical consumption of the oscillator
An object of the invention is also a method for generating an oscillating signal at an oscillation frequency, this method comprising:
the providing of the above radiofrequency oscillator, and the amplification of the part of the oscillating signal picked up at the output terminal and the injection of this amplified part of the oscillating signal at the control terminal in phase with the oscillating signal generated at the output terminal.
The embodiments of this method may comprise the following characteristic:
the control of the current source to generate a direct current, the intensity of which is strictly below the threshold beyond which a sustained precession of magnetization of the free layer appears;
BRIEF DESCRIPTION OF THE FIGURES
The invention will be understood more clearly from the following description, given purely by way of a non-exhaustive example and made with reference to the appended drawings, of which:
FIG. 1 is a schematic illustration of the architecture of a radiofrequency oscillator;
FIG. 2 is a schematic illustration in vertical section of a magnetoresistive device used in the oscillator of FIG. 1 ;
FIG. 3 is a flowchart of a method for generating an oscillating signal by means of the oscillator of FIG. 1 :
FIGS. 4 , 5 and 6 are schematic illustrations of alternative embodiments of a radiofrequency oscillator; and
FIG. 7 is a schematic illustration of the architecture of another magnetoresistive device that can be used in the oscillator of FIG. 1 .
DETAILED DESCRIPTION
In these figures, the same references are used to designate the same elements,
Here below in this description, the characteristics and functions well-known to those skilled in the art are not described in detail.
FIG. 1 shows a general architecture of a radiofrequency oscillator 2 . This oscillator 2 comprises:
a source 4 of direct current I d , a magnetoresistive device 6 equipped with an input terminal 8 connected to the current source 4 and to an output terminal 10 of the oscillating signal generated by this device 6 , and a low-noise amplifier 12 , the input of which is connected to the output 10 and the output of which is connected to the output terminal 14 of the oscillating signal generated by the oscillator 2 .
The device 6 is formed by a stack of magnetic and non-magnetic layers forming a tunnel junction also known as a TMR (tunnel magnetoresistance) junction. This stack comprises at least:
a magnetic layer, called a “reference layer”, capable of spin-polarizing the electrical current generated by the source 4 , and having a magnetization of fixed direction, a magnetic layer, called a “free layer”, the magnetization of which can oscillate when it is crossed by the spin-polarized current, and a non-magnetic layer, called a “spacer”, interposed between the two previous layers to create the tunnel junction.
The device 6 works as a spin transfer oscillator or STO when the intensity of the spin-polarized current crosses a threshold I c known as the “critical current of oscillation”. When the intensity of the spin-polarized current crosses this threshold I c , the magnetization of the free layer of the device 6 precesses sustainedly. Typically, the threshold I c corresponds to a current density greater than 10 7 A/cm 2 in the cross-section of the layers of the stack. If not, the device 6 behaves like a resonator, also known as an STR (spin-transfer resonator), and the oscillating signal generated is dampened and not sustained. However, even in this case, to generate the dampened oscillating signal, the current density in the cross-section of the layers of the stack must be high. Typically, the term “high density of current” designates current density greater than 10 6 A/cm 2 .
To obtain high current density, the cross-section of at least one of the layers of the stack typically has a diameter of less than 300 nm and preferably less than 200 or 100 nm. When the cross-section is not a disk, the term “diameter” must be understood to mean “hydraulic diameter”.
The source 4 generates a direct current I d the intensity of which, in this embodiment, is below the threshold I c but sufficiently high to give rise to a high current density in the stack of layers. Thus, here below in this description, the device 6 works as a resonator and not as a spin-transfer oscillator.
The oscillator 2 has different automatic control and feedback loops. To simplify the description, these are all shown in the same embodiment in FIG. 1 . However, in practice, these loops to be implemented are chosen as a function of the characteristics of the device 6 .
In FIG. 1 , the oscillator 2 comprises a frequency-locking loop 16 for the automatic control of the oscillating signal generated by the device 6 . This loop 16 is also known as a phase-locked loop or PLL. This loop 16 is directly connected between the terminal 10 and a terminal 18 for controlling the frequency and amplitude of the oscillating signal s(t) generated by the device 6 . This loop 16 comprises a frequency divider 20 capable of generating, from the oscillating signal s(t), an oscillating signal s(t)* with a lower frequency f osc-r . For example, the divider 20 divides the frequency f osc of the signal s(t) by at least 100. Here, the frequency f osc-r is from 1 to 100 MHz.
The loop 16 also has a reference clock 22 which generates a clock signal r(t) that is far more stable than the oscillating signal s(t) at a frequency f ref far below the frequency f osc . The frequency f ref is typically greater than 1 MHz and is, for example, from 1 to 100 MHz.
The divider 20 and the clock 22 are connected to respective inputs of a comparator 24 . This comparator 24 generates a signal C 1 (t) for controlling the frequency f osc at an output 26 . This signal C 1 (t) is built so as to reduce the divergence between the frequencies f osc-r and f ref .
The loop 16 also comprises an amplifier 28 capable of amplifying the signal C 1 (t) before injecting it into the control terminal 18 .
The oscillator 2 also has an amplitude-locking loop 34 for locking the amplitude A osc of the oscillating signal s(t) into a reference value A ref for the amplitude. To this end, the loop 34 includes a sensor 36 which measures the amplitude A osc . This measurement of the amplitude A osc is then transmitted to a comparator 38 to compare the amplitude measured with the value A ref . The comparator 38 is very swift and very precise. For example, the precision of the comparator 38 is within 10 μV. Such a comparator is for example made by means of transistors incorporated into the layers of the magnetoresistive device 6 .
This comparator generates a control signal C 2 (t) at the terminal 40 . This control signal C 2 (t) locks the amplitude A osc to the value A ref . The signal C 2 (t) is set up on the basis of the divergence between the amplitude A osc and the value A ref .
The signal C 2 (t) is injected into the terminal 18 after it has been amplified by an amplifier 41 .
Finally, the oscillator 2 also includes a feedback loop 44 to inject a control signal C 3 (t) into the terminal 18 enabling the dampened oscillations of the device 6 to be converted into sustained oscillations even if the intensity of the current I d is below the threshold I c . To this end, the signal C 3 (t) is a amplified periodic signal injected into the terminal 18 in phase with the signal s(t) generated at the same instant on the terminal 10 . The term “in phase” designates the fact that the phase shift between the signals C 3 (t) and s(t) is equal to zero or practically equal to zero. For example, this phase shift is smaller than π/20 rad. Here, the signal C 3 (t) is an amplified copy of the signal s(t) generated by the device 6 .
The loop 44 also comprises an amplifier 46 . in this embodiment, an input of the amplifier 46 is directly connected to the terminal 10 without going through the amplifier 12 and an output of the amplifier is directly connected to the terminal 18 . The gain of this amplifier is determined so as to compensate for the losses of the device 6 and thus obtain a sustained oscillation even if the intensity of the I d is lower than the threshold I c . Here, the gain of the amplifier 46 is determined experimentally. To this end, the losses of the device 6 are first of all determined experimentally and then a gain enabling compensation for these losses is fixed for the amplifier 46 .
The amplifier 46 has a bandwidth situated around the frequency f osc .
In order that the signals s(t) and C 3 (t) may be in phase, the loop 44 is as short as possible. For example, its length is smaller than 10 nm and preferably smaller than 1 nm or 100 μm.
To adjust the amplitude and frequency of the signal s(t) generated by the device 6 , the oscillator 2 is equipped with a magnetic field generator 50 . This generator 50 is placed relatively to the device 6 so that the lines of the magnetic field that it generates pass through the free layer of the device 6 .
For example, this generator 50 takes the form of a conductive track placed in the vicinity of the stack of the layers of the device 6 . The shortest distance between this conductive track and the free layer is less than 100 μm to limit the electrical consumption of the generator 50 . Advantageously, this distance will be smaller than 10 μm (integrated track) or even smaller than 1 μm. In FIG. 1 , the resistivity of this track is represented by a resistance 52 . For example, the resistance value 52 is equal to 10Ω and corresponds to the resistance of the conductive track between the terminal 18 and a reference potential such as the ground.
This generator 50 has a terminal that can be used to make the intensity of the generated magnetic field vary. Here, this terminal constitutes the terminal 18 . Indeed, a variation in the intensity of the magnetic field that passes through the free layer enables the amplitude and frequency of the oscillating signal generated by the device 6 to be modified.
Preferably, the terminal 18 is used when the device 6 is weakly tunable in frequency by means of the intensity of the spin-polarized current, or even very weakly tunable, The terms “weakly tunable” and “very weakly tunable” designate a magnetoresistive device for which the derivative, denoted as df osc /dI, of the frequency f osc as a function of the intensity I of the spin-polarized current, is strictly smaller than respectively 1 GHz/mA and 100 MHz/mA on the range of operation of this device. Weakly tunable magnetoresistive devices are generally planar structures that are easy to make. Planar structures are structures in which the magnetic moment of the reference and/or free layers is included in the plane of these layers. Under these conditions, the magnetoresistive device is generally weakly non-linear. The term “weakly non-linear” designates the fact that the derivative df osc /dA, of the frequency f osc as a function of the amplitude A of the variations of the resistance of the device 6 is smaller than 10 MHz/Ω on the range of operation.
Preferably, the loop 34 is used only if the device 6 is highly non-linear, i.e. the derivative df osc /dA is greater than 10 MHz/Ω and preferably greater than 100 MHz/Ω on the range of operation of the oscillator. It can be noted that, when a magnetoresistive device is highly non-linear, it is generally also highly tunable so that the generator 50 need not be used for this automatic control.
The loop 34 is typically used to correct fast frequency fluctuations (i.e. fluctuations of a duration smaller than 1 μs) and the loop 16 is used to correct slow fluctuations (i.e. fluctuations of duration greater than 1 μs).
Generally, on the range of operation of the device 6 , the variations of the frequency f osc as a function of the intensity I or of the amplitude A are linear or can be approximated by a linear relationship. Thus, the derivatives df osc /dI and ddf osc /dA are considered to be constant here below in this description.
FIG. 2 shows an exemplary embodiment of the magnetoresistive device 6 and of the generator 50 .
This magnetoresistive device 40 is shaped according to a geometry known as
CPP (current perpendicular to plane) geometry, More specifically. in FIG. 2 , the magnetoresistive device adopts a structure known as the “nanopillar” structure. This nanopillar is a pillar formed by stacking horizontal layers of the same horizontal section on top of one another.
Furthermore, the device 6 has a conductive electrode, respectively 60 and 62 , at each end of the pillar. These electrodes 60 , 62 enable the current that crosses the different layers forming the magnetoresistive device to be conveyed perpendicularly to the plane of these layers. The free ends of these electrodes 60 , 62 form, respectively, the terminals 8 and 10 of the device 6 .
When the intensity of this current exceeds the intensity of the critical current I c , the voltage between these electrodes 60 , 62 starts oscillating at the frequency f osc . This frequency f osc depends on the intensity of the current flowing across the electrodes 60 , 62 , For example, this voltage is transmitted to an electronic apparatus (not shown) which processes it in order to create a reference signal.
Between these electrodes 60 and 62 , the pillar has chiefly three layers, namely a reference layer 64 , a free layer 66 and a non-magnetic layer 68 interposed between the layers 64 and 66 . The non-magnetic layer is better known as a “spacer”.
These layers 64 , 66 and 68 are laid out and shaped so as to enable the appearance of magnetoresistive properties, i.e. a variation in the resistance of the pillar as a function of the directions of magnetization of the layers 64 and 66 .
To improve the readability of FIG. 1 , the proportions between the thicknesses of the different layers have not been maintained.
The width L of the different layers that form the pillar is constant. Here, the width L is smaller than 1 μm and typically ranges from 20 nm to 200 nm.
The reference layer 64 is made out of an electrically conductive magnetic material. Its upper face is in direct contact with the spacer 68 . It has a direction of easier magnetization contained in the plane of the layer.
The reference layer 64 has the function of spin-polarizing the electrons of the current that crosses it. It therefore has a thickness sufficient to fulfill this function.
For example, the reference layer 64 is made out of cobalt (Co), nickel (Ni), iron(Fe) or their alloys (CoFe, NiFe, CoFeB . . . etc.). The thickness of the reference layer 64 is of the order of some nanometers. The reference layer 64 may be laminated by the insertion of a few (typically 2 to 4) very thin layers of copper, silver or gold with a thickness of the order of 0.2 to 0.5 nm to reduce the spin-diffusion length. It is also possible for the layer 64 to be made of either an SyF (synthetic ferrimagnetic) or even an SAF (synthetic antiferromagnetic).
Here, the reference layer 64 has a magnetization of which the direction is fixed. The term “fixed-direction magnetization” designates the fact that it is more difficult to modify the direction of the magnetic moment of the reference layer 64 than it is to modify the magnetic moment of the free layer 66 . To obtain this, the magnetization of the reference layer 64 is for example trapped by a conductive antiferromagnetic layer 70 interposed between the reference layer 64 and the electrode 60 The upper face of the layer 70 is for example directly in contact with the lower face of the reference layer 64
Typically, the thickness of the layer 70 is from 5 to 50 nm. It can be made out of a manganese alloy such as one of the following alloys IrMn, PtMn, FeMn, etc. For example, this layer 70 is made out of a material chosen from the group comprising IrMn, FeMn, PtMn, NiMn.
The spacer 68 is a non-magnetic layer. This spacer 68 is thin enough to enable the spin-polarized current to pass from the reference layer 64 to the free layer 66 in limiting polarization loss. Conversely, the thickness of this spacer 68 is big enough to provide for magnetic decoupling between the layers 64 and 66 .
The spacer 68 is made out of an insulating material such as an aluminum oxide or nitride, a magnesium oxide, tantalum nitride, strontium titanate (SrTiO 3 ), etc. The pillar then has tunnel magnetoresistance (TMR) properties and the spacer 68 forms a tunnel barrier. In this case, the thickness of the spacer 68 is typically 0.5 nm to 3 nm
Here, the barrier tunnel of the device 6 is thick to show a high RA factor, i.e. a factor greater than 2 or 5 Ωμm 2 .
The RA factor of a tunnel barrier is the product of the resistance of the tunnel barrier multiplied by its area. Here, the area is the surface area of the cross-section of the tunnel barrier.
Generally, the higher the RA factor of the tunnel barrier, the greater will be the range of variation of the resistivity of the tunnel junction (for example it will be greater than 10%) and the more sensitive will the tunnel junction be to the precession of the magnetization in the free layer.
The free layer 66 is an electrically conductive magnetic layer, the magnetization of which can rotate or “precess” more easily than the magnetization of the reference layer 64 .
Many embodiments of the free layer are possible. For example, possible embodiments of this free layer are described in the patent application filed under number FR 0 957 888 and in the patent application published under number FR2 892 871.
The lower face of the layer 66 is in direct contact with the upper face of the spacer 68 . The upper face for its part is in direct contact with the electrode 62 . This layer 66 is for example made out of a ferromagnetic material such as cobalt, nickel or iron or an alloy of these different metals (for example CoFe, CoFeB, NiFe, etc.).
In the absence of spin-polarized current and of any external magnetic field, the direction M of the total magnetic moment of the layer 66 is oriented in parallel to the plane of this layer. The direction M then corresponds to the direction of easier magnetization of the free layer.
Typically, this stack of layers is made on the upper face of a substrate.
In the particular embodiment shown in FIG. 2 , the generator 50 is constituted chiefly by a conductive track 76 laid out relatively to the layer 66 so as to create a magnetic field, the field lines of which pass through this layer 66 . One example of a field line passing through the layer 66 is shown by the dotted line 78 in FIG. 2 . For example, this track 76 is laid out relatively to the layer 66 so that the magnetic field lines generated are parallel to the direction M of easier magnetization of the layer 66 . For example, here, the track 76 extends in a plane parallel to the plane of the free layer 66 and in a direction perpendicular to the direction M. Then, the current passing through the track 76 flows in the appropriate direction so that the magnetic field generated passes through the free layer 66 in the direction M of easier magnetization.
To minimize the intensity of the electrical current in the track 76 which enables the generation of a magnetic field of at least 10 Oe in the free layer 66 , this track 76 is attached without any degree of freedom to the layer 66 . The unit “Oe” is one Oersted (=10 −4 Tesla). For example, here, the track 76 is deposited or etched on a layer of dielectric material lying directly on the layer in which the electrode 62 is formed, The track 76 is insulated from the electrode 62 by the thickness of the layer made of dielectric material. Thus, the track 76 is separated from the free layer 66 by a minimum distance that is smaller than 1 μm and preferably smaller than 400 nm.
The use of the magnetic generator 50 to set the frequency or amplitude of the oscillating signal has the following advantages.
For example, when the device 6 is weakly tunable by means of the intensity of the spin-polarized current, this generator makes it possible to reduce the electrical consumption of the oscillator 2 needed to make the loops 16 , 34 and/or 44 operate. To illustrate this, the following typical numerical values are used: df osc /dI=60 MHz/mA and df osc /dH=10 MHz/Oe, where H is the intensity of the magnetic field that passes through the free layer 66 . The resistance of the device 6 between the terminals 8 and 10 is taken to be equal to 300 Ω.
With these values, to obtain a variation of 10 MHz in the frequency f osc , it is necessary to make the intensity of the polarization current vary by 0.17 mA, which corresponds to a consumed power equal to 8.5 μW (=300 Ω*(0, 17 mA) 2 ).
To obtain the same variation of frequency f osc in using the generator 50 , it is necessary for this generator to generate a variation of 1 Oe in the magnetic field that passes through the free layer 66 . Such a variation in the intensity of the magnetic field can be created by means of a 0.3 mA current flowing in the track 76 . Thus, the same variation of the frequency f osc in using the generator 50 consumes only 0.9 μW (=10 Ω*(0.3 mA) 2 ).
Thus, the use of the generator 50 makes it possible to greatly reduce the electrical consumption of the automatic control and/or feedback loops of the oscillator 2 . This results from the fact that the field tunability of the device 6 , represented by the derivative df osc /dH, is generally far greater than the tunability in intensity, represented by the derivative df osc /dI, of a large number of magnetoresistive devices and especially for weakly tunable devices.
This generator 50 also enables the setting of the frequency or amplitude of the signal s(t) even if the derivative df osc /dI is very low or equal to zero.
The working of the oscillator 2 shall now be described in greater detail with reference to the method of FIG. 3 .
Initially, at a step 90 , the current source 4 is controlled to generate a direct current I d whose intensity is strictly below the threshold I c . Thus, the device 6 behaves like a resonator.
parallel, at a step 92 , the amplifier 46 amplifies the part of the signal s(t) picked up at the terminal 10 and, in phase, injects its amplified copy C 3 (t) into the terminal 10 . The loop 44 thus enables compensation for the losses of the device 6 so as to obtain a sustained oscillation even if the intensity of the current I d is strictly below the threshold I c . Since the intensity of the current I d used is lower, the RA factor of the tunnel barrier of the device 6 can be increased so as to increase the sensitivity of the device 6 and of the oscillator 2 . This makes it possible to relax the manufacturing constraints for the device 6 .
It has been noted that the quality factor of the oscillator formed solely by the combination of the loop 44 with the device 6 increases as and when the intensity of the current I d increases. Thus, the quality factor may be set by adjusting the intensity of the current I d . This can be put to use to limit the consumption of the oscillator 2 when a high quality factor is not needed.
At the same time, at a step 94 , the loop 34 locks the amplitude A osc of the oscillations of the signal s(t) into the value A ref . To this end, at the step 94 , the sensor 36 measures the amplitude A osc . Then, the comparator 38 compares the amplitude A osc with the value A ref and generates the control signal C 2 (t) capable of reducing the divergence between the amplitudes A osc and the value A ref . The signal C 2 (t) is injected after amplification by the amplifier 41 at the terminal 18 .
The amplitude A osc of the oscillations of the signal s(t) is linked by a monotonic function N to the frequency f osc . Thus, the locking of the amplitude A osc to the value A ref locks the frequency f osc into a reference frequency corresponding to N(A ref ).
However, the comparison of the amplitude A osc and the value A ref is done far more quickly than the comparison of the frequencies f osc-r and f ref . Indeed, to compare an amplitude with a value, it is not necessary to apply a frequency divider. Thus, the loop 34 reacts far more speedily than the loop 16 and therefore enables compensation for fast fluctuations of the frequency f osc which the loop 16 is not able to compensate for. Since the automatic control loop 34 is far speedier than a frequency locking loop, the quality factor of the oscillator 2 is thereby improved.
Finally, in parallel with the steps 92 and 94 , at a step 96 , the loop 16 locks the phase of the signal s(t) into the phase of the reference signal r(t), To this end, the divider 20 divides the frequency of the signal s(t) to obtain the signal s(t)* with a frequency f osc-r . The signals s(t)* and r(t) are then compared by the comparator 24 . The comparator 24 then generates a signal C 1 (t) as a function of the divergence between the phases of the signals s(t)* and r(t). This signal C 1 (t) is built to reduce this divergence. It is applied after having been amplified by the amplifier 28 on the terminal 18 .
Thus, the loop 16 makes it possible to keep the signal s(t) in phase with the signal r(t).
At a step 98 , the different control signals generated during the steps 92 to 94 and 96 get added to each other and are injected into the same control terminal 18 . These control signals then make the intensity of the magnetic field vary in proportion to the intensity of the electrical currents generated by the loops 16 , 34 and 44 . This modification of the intensity of the magnetic field modifies the amplitude and frequency of the signal s(t) generated by the device 6 at the terminal 10 . In order that the sensitivity of the device 6 to the variations of intensity of the magnetic field may be high, the gain of the amplifiers 28 and 41 is set so that the intensity of the current injected into the track 76 gives a magnetic field of at least 10 Oe in the free layer. Indeed, below this intensity for the magnetic field, the variations of the frequency f osc are difficult to perceive.
The steps 90 to 98 are repeated in a loop.
Many other embodiments of the oscillator 2 are possible. In particular, the loops 16 , 34 and 44 can be used independently of one another. For example, the frequency-locking loop 16 can be omitted,
Each of these loops 16 , 34 and 44 can be linked either to the control terminal 18 or to a terminal for controlling the intensity of the frequency f osc .
More specifically, when the magnetoresistive device is highly tunable by means of the intensity, i.e. when the derivative df osc /dI is greater than 1 GHz/mA, the automatic control or feedback loops are connected to a terminal for controlling the intensity of the current delivered by the current source. One example of such an embodiment is illustrated in FIG. 4 . In the oscillator 100 of FIG. 4 , the terminal 18 is replaced by a terminal 102 for controlling the intensity of the current I d . In the oscillator 100 , the loop 16 has also been omitted.
The source 4 is replaced by a direct current source 104 , the intensity of which is controllable as a function of the signal injected into the terminal 102 .
The loops 34 and 44 are connected to this terminal 102 instead of the terminal 18 .
In other embodiments, certain loops may be connected to the terminal 18 while other loops are connected to the terminal 102 . One example of such an embodiment is illustrated in FIG. 5 . FIG. 5 represents an oscillator 110 in which the feedback loop is connected to the terminal 102 for controlling the intensity of the source 104 while the amplitude-locking loop is connected to the terminal 108 for controlling the magnetic field. In this embodiment, the loop 16 is also omitted.
As a variant, it is possible to simultaneously connect one or more of the loops 16 , 34 and 44 both to a field control terminal, such as the terminal 18 , and to an intensity control terminal, such as the terminal 102 . In this case, preferably, an adjustable distributor is introduced to adjust the distribution of the control signal between these two terminals. This distributor is set manually or automatically so as to maximize the sensitivity of the magnetoresistive device to the control signal sent. This makes it possible to adapt to any type of radiofrequency oscillator without having to modify the automatic control or feedback loops.
The amplifier 46 of the feedback loop can also be placed between the terminals 10 and 14 as illustrated in FIG. 6 . FIG. 6 represents a radiofrequency oscillator 120 . This embodiment reduces the gain of the amplifier 12 . Indeed, the amplifier 12 is series-connected with the amplifier 46 .
Many other embodiments of the magnetoresistive device 6 are possible. For example, the direction of easier magnetization of the free layer and/or of the reference layer is not necessarily contained in the plane of the layer. For example, the direction of easier magnetization can be perpendicular to the plane of the layer.
Additional layers can be inserted into the stack of layers forming the pillar of the device 6 . For example, an antiferromagnetic layer can be inserted between the free layer 66 and the electrode 62 .
The reference layer may be a synthetic antiferromagnetic to fix the direction of its magnetization. In this case, the layer 70 can be omitted.
One (or more polarizers) can also be used to make the magnetoresistive device in addition to the reference layer. A polarizer is a magnetic layer or multilayer, the magnetization of which is outside the plane of the layer and, for example, perpendicular to the plane of the layer. The polarizer enables the spin-polarizing of the current that passes through it. Typically, the polarizer is formed by several sub-layers superimposed on one another, for example an alternation of magnetic and metallic layers for example (ColPt) n ). Here, the polarizer is not described in greater detail. For further information on polarizers, reference may be made to the patent application FR2 817 998. The presence of the polarizer makes it possible to obtain a precession of the magnetization of the free layer outside its plane. This makes it possible for example to make the oscillator work in a zero field, i.e. in the absence of a static external magnetic field. For example, a polarizer is deposited directly beneath the electrode 62 .
The cross-sections of the different layers forming the magnetoresistive device are not necessarily all identical. For example, the magnetoresistive device can also be made with a stacking structure known as a “point-contact” structure. Such structures are described in the patent application FR 2 892 871.
The spacer 68 can be made out of an electrically conductive material such as copper (Cu). The magnetoresistive properties of the pillar are then qualified as giant magnetoresistance (GMR) properties. In this case, the thickness of the spacer 68 is typically greater than 2 nm. Generally, its thickness ranges from 2 to 40 nm and is preferably equal to 5 nm to ±25%. Furthermore, typically, the thickness of the reference layer is strictly greater than the spin diffusion length (see for example the patent FR2 892 871 for a definition of this term).XXX
The device 6 can be replaced by an assembly of magnetoresistive devices series-connected or parallel-connected to one another to increase the power of the oscillating signal. In this case, the input and output terminals of these different magnetoresistive devices are connected respectively to common input and output terminals. The amplitude and/or frequency-locking loops are connected to these common input and output terminals. Preferably, if a feedback loop is used, it is placed only locally at the terminals of each of the magnetoresistive devices, Thus, in a particular embodiment, each magnetoresistive assembling device comprises its own feedback loop.
The intensity control terminal can be an input terminal of a current summing unit, another input terminal of which is connected to the output of a non-controllable direct current source. The output of this summing unit, at which the sum of the currents is generated, is directly connected to the input terminal 8 of the device 6 .
Other layouts of the conductive track 76 forming the field generator 50 are possible. For example, as a variant, the conductive track 76 extends in parallel to the free layer in the same plane as this layer. The track 76 can also be deposited and/or etched beneath the stack of layers 64 , 66 and 68 . For example, in this case, the track 76 is deposited and etched on the substrate 74 . Furthermore, it is not necessary for the field lines generated by this track 76 to cross the free layer in parallel to its direction of easier magnetization. For example, in a preferred variant, the field lines cross the free layer with a direction perpendicular to the direction of easier magnetization of this free layer.
Magnetic field generators other than a conductive track can also be used.
As a variant, the generator 53 , in addition to the magnetic field built from the control signals C i (t), generates a static magnetic field which adjusts the main oscillation frequency f osc .
Since there is a relationship N between the amplitude A osc and the frequency f osc , it is possible to set up a frequency locking by directly measuring the amplitude A osc . For example, to this end, the measured amplitude is converted by means of the predetermined relationship N into a measured frequency N(A osc ). Then, the frequency N(A osc ) is compared with a reference frequency f ref . A comparator then generates a control signal as a function of the divergence between these frequencies N(A osc ) and f ref , enabling this divergence to be reduced. This control signal is then injected into the control terminal 18 or 102 .
As a variant, the source 4 generates a direct current I d , the intensity of which is greater than or equal to the threshold I c . In this case, the loop 44 can be omitted. However, it can also be kept to improve the quality factor of the oscillator
In another variant, it is possible to integrate a phase-shifter into the loop 44 . This phase-shifter then has the function of keeping the signal C 3 (t) injected into the terminal 18 in phase with the signal s(t).
The characteristics of the dependent claims can be implemented independently of the characteristics of the independent claims. For example, the use of the terminal 18 of the generator 50 of the magnetic field to loop the loops 16 , 34 or 44 can be implemented independently of the use of a feedback loop 44 comprising the amplifier 46 equipped with:
an input connected to the output terminal ( 10 ) so as to amplify the part of the oscillating signal picked up at the output terminal, and an output connected to the control terminal 18 or 102 so as to inject, into this control terminal, an amplified part of the oscillating signal in phase with the oscillating signal generated at the output terminal.
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The invention relates to a radiofrequency oscillator which incorporates: a spin-polarized electric current magnetoresistive device ( 6 ) for generating an oscillating signal at an oscillation frequency on an output terminal ( 10 ), and a terminal ( 18 ) for controlling the frequency or amplitude of the oscillating signal, and a feedback loop ( 44 ) comprising an amplifier ( 46 ) provided with: an input connected to the output terminal ( 10 ) of the magnetoresistive device ( 6 ) so as to amplify the portion of an oscillating signal detected at the output terminal, and an output connected to the control terminal ( 18 ) so as to inject onto said control terminal the amplified portion of the oscillating signal which is phase-related to the oscillating signal generated at the output terminal.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application is a continuation of U.S. patent application Ser. No. 10/229,440 filed on Aug. 28, 2002, which is a division of U.S. patent application Ser. No. 09/371,717, filed on Aug. 9, 1999, now issued as U.S. Pat. No. 6,714,121. These applications are incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to radio frequency identification, and more specifically to a tracking system, method, and components for use with radio frequency identification.
BACKGROUND OF THE INVENTION
Numerous systems exist for the physical tracking of inventory, raw materials, materials in manufacture, or other items in a variety of locations, such as manufacturing facilities, libraries, offices, and the like. Accurate and inexpensive locating, tracking, and inventorying of the physical location of items such as parts, goods, and materials is a necessity for many operations, such as manufacturing and warehousing, for a number of reasons. Such reasons include the desire or need to quickly determine the physical location of a part in the manufacturing process, or to determine whether a part is present in inventory or storage, to determine the quantity of an item on hand, to track the progress of an item in manufacture, and many other such functions.
Apparatuses and methods for the performance of the tracking of material and the performance of inventory-like processes have evolved over time. For example, inventory strategies have been modified from the hand tallying of stock and location in a notebook or the like, to sophisticated computer driven hardware and software for tracking inventory. Traditionally, a full inventory operation could close an entire facility, such as a retail store, warehouse, or manufacturing plant, for a day or more every time a detailed inventory was required. The large costs associated with physically shutting down an operation to do inventory were and are a known cost of the operation of many businesses.
An accurate record of the items available in a store or warehouse, as well as their location, is a key component of successfully operating a business. Knowing what is on hand allows the skilled manager or supply personnel to make informed ordering decisions. Knowledge of the availability and location of items or parts in a facility decreases the amount of time necessary for retrieval of such items, thereby increasing overall efficiency.
The advent of computers, and their rapid entrenchment into mainstream businesses and personal life, has also led to an advent in tracking items and performing and maintaining an inventory. For example, when physical inventory was still routinely performed by hand, a database could be created and maintained to track inventory in a more dynamic fashion. The potential errors of misplacing the physical inventory sheet, and the potential corruption of the physical inventory record were replaced with the increasingly lower incidence of potential errors of lost data and data corruption. Data entry error still also posed potential human error problems. Still, the computerized storage and retrieval of inventory information allowed for various sorting and categorization of data not previously easily available. The database functions of hand entered computer inventories were readily extended to other material tracking endeavors such as warehousing, stocking, ordering, and the like.
As technology continued to advance, various apparatuses and methods for tracking the inventory of a retail store, manufacturing plant, warehouse, and the like, in real-time or near real-time, were placed into use. Production lot tracking technology systems had and have widely varied capability, success, ease of use, and cost. Currently proposed and available lot tracking technologies include manual keyboard entry, bar coding, and proprietary systems such as those provided by JENOPTIK, Fluoroware, Micron Communications, Inc., and Omron.
Manual keyboard entry of lot numbers of parts in a lot tracking or inventory situation is already in use in many facilities. Such systems are not automated, but instead are manually performed. The physical inventory process is still undertaken, and generally the information gathered is entered into a computerized database. Data entry errors due to human error are in large part an unavoidable part of the manual inventory process. Such errors are difficult if not impossible to track and correct. Any information which is desired or required to be obtained and stored or entered into a computer or other system beyond a simple inventory creates additional work for the inventory taker. The time it takes to perform an inventory using manual keyboard entry of lot numbers and the like is not significantly less than traditional pencil and paper inventories which often require the full or at least partial shutdown of an entire facility. Such an inventory process is subject to high costs reflected not necessarily in terms of equipment, but in terms of employee-hours and lost revenues from a shutdown.
Because of its advantages over manual inventory, whether using a computer for further organization or not, bar coding has become commonplace in many if not most retail outlets and warehouses, grocery stores, chains, and large retail outlets. In a bar coding scheme, an identifying label containing encoded information is placed on the goods, parts, part bin, or other item to be identified by a bar code reader. The encoded information is read by the reader with no user data entry generally required. This is referred to as keyless data entry. The information encoded on the bar code is then typically passed to a computer or other processing medium for decoding and data entry. Such data entry is largely error free due to the decreased reliance on error-prone human activities. Bar code data entry is also typically faster than manual data entry.
Bar coding is a common and easy to implement technology. However, bar coding requires a scanner or reader for every terminal, or a portable scanner which is moved around from location to location. Further, bar coding requires a separate label for implementation. Without further data entry, which has additional associated costs and potential error factors, other desired or required information such as an exact location of the scanned item is unknown.
Another type of lot tracking system uses an infrared lot box micro terminal with a pager-like display for lot tracking. A micro terminal is physically attached to each lot box. Each micro terminal communicates via infrared communication with an infrared (IR) transceiver grid, which must be in sight of the micro terminal in order for the system to function properly. Typically, the IR transceiver grid is positioned or installed along the ceiling of a facility. Stacked pallets, lots, or wafer boats will be unreadable using an IR system. The micro terminals and IR transceiver grid of the IR system are expensive. A micro terminal system requires an elaborate software platform, but does allow for reduced data entry error, faster data entry, and simple user entries. The IR system requires a major procedural change in the standards for performing lot tracking. The micro terminals must also be positioned in a specific orientation with respect to the transceiver grid for proper functioning. The terminal must be physically attached to a lot box to be tracked. Lot location can only be identified to an area as small as the IR field of view.
Another lot tracking system is available from Fluoroware. This system uses passive tags in a cassette. The passive tags are scanned by a scanning station over which an item, wafer boat, or lot which has been tagged passes. The item, lot, or boat is identified when it passes over the scanning station. Often, wafer boats are specific to the particular station, but parts may be moved to a number of different locations. Tracking a cassette may require a large amount of reassociation of the tag information to accurately track the part or item. The scanning stations of the Fluoroware system are expensive, on the order of $2,000-$3,000 per station. Additionally, a main computer to centralize, organize, and coordinate operation of the tracking system is required. The Fluoroware system, like other more automated systems, reduces data entry error and data entry time. The tags used in the system are relatively low in cost, and can be embedded into boats. However, many controllers are needed for the system, and the scanning stations have a high cost. Further, the reassociation of tags with different locations requires extra data entry or tag reprogramming, which introduces further potential errors.
When an inventory or lot tracking system works with a large number of parts or locations, which may number into the thousands of locations and many thousands if not millions of parts, the systems described above become unwieldy to effectively operate, become cost prohibitive, or both. Further, with a large number of parts and locations, an exact location match is difficult if not impossible to provide with the above systems. Such a lack of ability to pinpoint the location of a part further hinders the operation and effectiveness of the above systems.
Additionally, items or lots in a manufacturing facility may sit in a certain location without being used or moved for weeks or more. In addition, the pallets of wafer boats in such a facility or storage area may be stacked in stacks five or more layers deep. Personnel are often assigned to physically search all lots to find a lot which may be missing. Lots in large manufacturing facilities have been known to be lost for 6 months to a year. A more accurate tracking system for lots would be desirable.
In manufacturing situations, other tracking of inventory and parts is often desirable or necessary. Such other tracking may include tracking the amount of time a part spends between stations, the amount of time it takes for a part to complete a certain operation, a history of the travel of a part from start to finish of a manufacturing or fabrication operation, and the like.
SUMMARY OF THE INVENTION
The present invention solves the above-mentioned problems in the art and other problems which will be understood by those skilled in the art upon reading and understanding the present specification. The present invention provides a method and apparatus for tracking items automatically. An apparatus embodiment of the present invention is a passive RFID (Radio Frequency IDentification) tag material tracking system capable of real-time pinpoint location and identification of thousands of items in production and storage areas. Passive RFID tags are attached to the item to be tracked, remote sensing antennas are placed at each remote location to be monitored, scanning interrogators with several multiplexed antenna inputs are connected to the sensing antennas, and a host computer communicates with the interrogators to determine item locations to an exacting antenna position.
Another embodiment of the present invention is a method for tracking the location of an object having an identification tag attached to or near the object, using an interrogator connected to a sensing antenna and to a computer, comprising activating the sensing antenna, determining if there is a voltage at the sensing antenna, obtaining data from a passive identification tag attached to the object, and communicating between the host computer and the interrogator to log tag location data.
Still another embodiment of the present invention is an RFID material tracking system, comprising a plurality of RFID tags, each tag attachable to a container or an item to be tracked, a plurality of sensing antennas, each antenna placeable at a location to be monitored, a plurality of interrogators, each interrogator having a plurality of antenna inputs, each of the plurality of sensing antennas connected to an interrogator, and a computer operatively connected to each of the interrogators and receiving tag location information therefrom to log tag location data.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, where like numerals refer to like components throughout the several views,
FIGS. 1A and 1B are perspective drawings of a dual nesting station with a container having an RFID tag embedded therein;
FIG. 2 is a perspective view of a storage shelf having a plurality of nesting stations with some tracked container placed thereon;
FIG. 3 is a block diagram view of a system embodiment of the present invention;
FIG. 4 is a schematic diagram of an embodiment of a circuit layout for a 2×2 pad embodying the invention;
FIG. 5 is diagram of an embodiment of an antenna suitable for use in the embodiment of claim 1 ;
FIG. 5 a is a top view of another embodiment of an antenna suitable for use in the embodiment of claim 1 ;
FIG. 5 b is a section view of the embodiment of FIG. 5 a taken along lines 5 b - 5 b thereof;
FIG. 6 is a circuit diagram of an embodiment of a tuned circuit according to the invention;
FIG. 7 is a block schematic diagram of an embodiment of an interrogator of the present invention;
FIG. 7 a is a schematic diagram of an RF harmonic reduction embodiment of the driver system;
FIG. 8 is a block diagram of another embodiment of an interrogator system of the present invention;
FIG. 9 is a block diagram of another system embodiment of the present invention;
FIG. 10 is a side elevation view of an another antenna embodiment of the present invention;
FIG. 11 is a flow chart diagram of a method embodiment of the present invention;
FIG. 12 is a flow chart diagram of another method embodiment of the present invention;
FIG. 13 is a flow chart diagram of a lot association method of the present invention;
FIG. 13 a is a flow chart diagram of another method of the present invention;
FIG. 14 is a flow chart diagram of an embodiment of a tag attachment method of the present invention;
FIG. 15 is a perspective diagram of a computer system on which various embodiments of the present invention may be implemented; and
FIG. 16 is a schematic diagram of annunciator embodiments of the present invention.
FIG. 17 is a block diagram of another embodiment of an application for the present invention.
DESCRIPTION OF EMBODIMENTS
In the following detailed description of the embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
The physical similarities between inventory operations and other similar operations such as warehousing, quantity and position tracking, and the like allow the discussion of one such operation to generalize for a number of similar operations. As such, this description will discuss generally a variety of inventory strategies, with the understanding that generalization to other operations may easily be accomplished by one of ordinary skill in the art. Such modification and specification are therefore within the scope of the present invention.
Physical Overview
An implementation of a portion of a container tracking and identification system according to the present invention is shown in FIGS. 1A , 1 B and 2 . Referring to FIG. 1 , a dual nesting station 10 is shown upon which an item or container 12 may be placed. Hereafter, reference to container will mean any item which may be tracked by the present invention. The dual nesting station contains two locations 14 , 16 where containers may be placed and tracked according to the present invention. A dual nesting station 10 is shown as an exemplary embodiment, however, those skilled in the art will readily recognize that a single nesting station 14 may be implemented, or any plurality of nesting stations may be implemented in accordance with the teachings of the present invention. The nesting stations 14 , 16 may be implemented as a generally flat component which may be placed wherever there is a need to track a container, or it may be formed as an integral part of a shelf, pallet, bench, table, or any other location where items or containers are located.
Each nesting station includes an antenna 18 imbedded within of upon each nesting stations 14 , 16 . Other circuitry, not shown in FIGS. 1A and 1B but described below, is used to send and receive signals to and from an RFID tag 19 imbedded within or placed upon container 12 . As shown in FIG. 1A , when container 12 is placed in proximity to nesting station 14 , communication of signals between container RFID tag 19 and antenna 18 is possible. These communication signals will be more fully described below.
FIG. 2 shows an exemplary implementation of a shelf arrangement 20 with which the present invention may be used. A plurality of nesting stations 16 are part of the shelf arrangement with each nesting station 16 having an integral antenna 18 for each shelf location. Containers 12 or other items to be tracked, can be placed at various shelf locations and the containers 12 can be located, identified, tracked, etc., with the teaching of the present invention. An optional feature of the present invention is the use of annunciators or indicators 22 which may be used to indicate the location of a desired container. Nesting stations 16 may be placed upon the shelves or they may be integrated with the shelf itself.
System Overview
Referring now to FIG. 3 , an embodiment 100 of a system of the present invention is shown in block diagram. Lot tracking system 100 comprises a host or control module 102 operatively connected to a plurality of interrogators 104 , 106 , and 108 . The interrogators 104 , 106 , and 108 each have a plurality of sensing antennas and circuitry 110 operatively connected to the main interrogator body by connection lines. The interrogators 104 , 106 , and 108 are preferably local to the sensing antenna circuits 110 . The sensing antenna circuits 110 are positioned so that they are in sensing proximity to a location at or over which a plurality of containers may be located or pass. Each container (shown in FIGS. 1A , 1 B and 2 ) is capable of holding items such as lots of wafers used to manufacture integrated circuits. In such an application of the present invention, the container is termed a “boat” and would hold lots of partially fabricated or fully fabricated wafers which may be routed through the plurality steps required in the IC fabrication at an IC foundry.
Each container has an attached Radio Frequency IDentification (RFID) tag 19 (shown in FIGS. 1A , 1 B and 2 ) capable of being excited by the sensing antenna circuits 110 , capable of relaying, conveying, or communicating identification information to the sensing antenna circuits, and on to the control module 102 .
The tags are preferably low frequency passive RFID tags 19 which carry a serial number or identification number which can be cross-referenced within a database or other data structure maintained by the control module 102 or one of its components. Each interrogator 104 , 106 , and 108 contains drive electronics and detection circuitry to excite and read back identification information contained on a tag. Driving information is communicated to the tag through the antenna coil or primary of an electromagnetically coupled circuit. The data out on the communication line 114 , 126 , 140 is linkable to the host or control module system for other action. Tags are polled by exciting the sensing antenna circuits 110 , which induces a current in the tag 19 , causing it to communicate its stored information, which will be described in more detail below.
The RFID tags 19 contain generally simple information, but the tag information may be as widely varied as the uses for the system 100 itself. For example, tags can contain simple presence/no presence bit, or detailed information regarding an entire build process, or specifications about lot number, serial number, and the like. The radio frequency of the interrogator powers up the tag, and the carrier frequency (usually 125 KHZ for passive tags in one embodiment) becomes the clocking frequency to generate a clock to clock the data out. Passive tags can be made and used very inexpensively, making them more economical for use with multiple read locations.
In one arrangement shown in FIG. 3 , interrogator 104 is operatively connected to a plurality of sensing antenna circuits 110 on a nesting station 112 via connection lines 114 . In this arrangement, two quad-nesting stations are shown. In another arrangement, interrogator 106 is operatively connected to a plurality of sensing antenna circuits 116 on quad nesting station 118 via connection line 120 , and to antennas 122 of dual nesting station 124 via connection line 126 . In yet another arrangement, interrogator 108 is operatively connected to a plurality of antenna circuits 128 on a dual nesting station 130 via connection line 132 , and to antenna circuits 134 on another dual nesting station 136 via connection line 138 . Further interrogators may be added to the embodiment 100 to accommodate more nesting stations.
Control module 102 may include such components as a computer with a database of information pertaining to lot numbers, lot locations, and other lot information for the items in container 12 . Control module 102 controls the interrogators 104 , 106 , 108 to poll appropriate locations to gather and maintain information about containers 12 .
The connection lines of embodiment 100 may comprise a plurality of types of connections such as standard flat phone cables with a phone jack connector to attach to multiple sensing antennas. Depending upon the configuration of the nesting station to which the connection lines are connected, the telephone cables used in embodiment 100 may be four conductor flat phone cables, eight conductor flat phone cables, or a combination of such cables. The connector phone jack may be an RJ-11 type four conductor jack, or an RJ-45 type eight conductor jack, depending upon the type of cable connection. Flat telephone cable is used so that the drive signals for the antenna circuits (described below) are physically separated from the sense line and are readily available at low cost.
Alternatively, twisted pair cabling may be used in a network environment. In such a configuration, the detection and ground wires (described below) would be twisted together, and the drive signal lines would be twisted together. Only one drive wire is active at any one time. One antenna circuit 110 is driven at a time, and a common detection circuit is used for all of the antennas. The drive signal is switched from one antenna circuit to the next using a multiplexor (MUX). The switching may be sequential, ordered, or random, but only one antenna circuit 110 is driven at any one given time. This allows the use of a common detection processor detection circuit which is used for each antenna circuit of the plurality of antenna circuits that are wired into each interrogator. The multiplexor selects which antenna circuit is being driven by the drive signal.
The jacks for the connection can be standard telephone connection jacks, selected for their availability and low cost. Those skilled in the art will readily recognize that a wide variety of wire types, wiring configurations and electrical connectors may be used in the implementation of the present invention without departing from the spirit and scope of the present invention.
Nesting stations have been described above as single-, dual- or quad-, but many other arrangements of nesting stations is possible with the present invention. For the example of tracking boxes of semiconductor wafers, each nesting station would be typically implemented as a dual nesting station sized to be approximately one foot by 2 feet to form a suitably sized location for two typical 200 millimeter wafer boxes which have a footprint of approximately one square foot. This is referred to as a 1×2 pad. A 2×2 pad would be implemented as a quad nesting station described above and would be approximately two feet by two feet in size. Thus, a 2×2 would be a quad nesting station for four semiconductor wafer boxes.
For a 1×2 pad nesting station such as nesting station 124 , 130 , or 136 , an RJ-11 four conductor jack may be used to connect the four conductor telephone cables 126 , 132 , and 138 , respectively, to the antenna circuits 122 , 128 , and 134 respectively. For a 2×2 pad nesting station such as nesting station 112 or 118 , an RJ-45 eight conductor jack may be used to connect the eight conductor telephone cable 114 or 120 respectively to the antenna circuits 110 or 116 .
Alternatively, instead of an eight conductor cable such as cable 114 or cable 120 , two four conductor cables can be used side by side in an RJ-45 jack. In this case, the opposite ends of the four conductor cables may be fitted with RJ-11 phone jacks for ease of connection. This configuration is useful for connection of two 1×2 pads such as pads 130 and 136 to a single interrogator such as interrogator 108 . For example, in FIG. 3 , cables 132 and 138 may be four conductor telephone cables, each having an RJ-11 jack for connection of the cables to the nesting stations 130 and 136 . The two cables 132 and 138 plug into a single RJ-45 eight position jack to connect the cables to interrogator 108 . When two four connector cables are used in a single RJ-45 eight conductor jack, they are mirrored so as to place the detector circuit, that is the signal that has been rectified and has the greatest noise sensitivity, on the outside of the cable where it is furthest from the drive electronics.
Nesting Pad Description
FIG. 4 shows an exemplary embodiment of a 2×2 pad 152 implemented with two 1×2 pads 154 and 156 , along with the antenna circuitry, arranged in a mirrored configuration (discussed below) in schematic diagram form. A connection 158 for cabling to the interrogator has eight contact positions 160 which may comprise two four conductor RJ-11 jacks, or a single eight conductor RJ-45 jack as described above. Each 1×2 pad 154 and 156 has a four conductor RJ-11 jack connecting its four contact positions, 162 and 164 respectively, to an appropriate four conductor cable to the interrogator. As shown, the physical layout of contact positions 162 mirrors that of the physical layout of contact 164 , with position 162 - 4 and position 164 - 4 being adjacent within the 2×2 pad 152 . This mirrored configuration places the detection circuit, that is the rectified signal with the greatest noise sensitivity, on the outside of the cable. The detector conductors (position 1 ) are therefore placed away from the drive signal conductors (positions 3 , 4 ) by the ground conductors (position 2 ) to help eliminate noise.
The antennas used in embodiment 100 preferably each comprise a flat coil, a flat radial single layer antennas comprising a length of copper wire which is coiled to form an antenna. The flat coil construction allows some degree of side to side movement of the antenna without significant degradation of performance. Further, the flat coil antenna construction also provides relatively good height detection of the antenna without drastically affecting the performance of the system. A flat coil is less sensitive to surrounding metal surfaces in the same plane as the coil. Other antennas could also be used. Representative embodiments of antennas will be discussed further below.
Antenna Circuit Description
FIG. 5 shows a top view of a representative embodiment of a flat antenna coil 200 is shown in FIG. 5 . Antenna coil 200 comprises a length of coiled wire 202 , such as copper wire. Although copper wire is preferred, other conductive wires and embodiments are well within the scope of the invention, as will be known by one of skill in the art.
FIG. 5 a shows a top view of another embodiment 250 of an antenna. Antenna 250 comprises a substantially circular magnetic core 252 having an annular ring 254 extending from the core 252 to form a magnetic cup. A magnetic center post 256 extends from the core 252 approximately at the center of core 252 , in the same direction as the annular ring 254 . Coil windings 258 are wrapped around the center post 256 . FIG. 5 b shows a section view of antenna 250 taken along lines 5 b - 5 b of FIG. 5 a . FIG. 5 b shows focused flux lines 260 from the focused antenna 250 .
As shown in FIG. 6 , each antenna circuit 300 form a tuned tank circuit which is connected to interrogators 104 , 106 , and 108 . The interrogators contain circuitry for excitation of the tuned tank circuits and for detection of the information transmitted by an excited RFID tag. Since the nesting stations are somewhat remote from the interrogators, the tuned circuit embodiment 300 of the present invention places a capacitor 302 in close proximity to the antenna coil 304 , so that the entire tank circuit 300 is remote. Therefore the cable length and type can vary or be changed without affecting the operation of the antenna 304 and drive electronics.
One skilled in the art will recognize that if the capacitive element and the antenna coil were separated, with the capacitive element located at an interrogator would require that the interrogator be part of the tuned circuit. Cabling between the antenna (nesting station) and the capacitive element (interrogator) would be a factor in deciphering information from any excited tag. In such a configuration, when the location of the antenna changed, the tuning of the circuit changed. This latter configuration would be problematic since tuning the tank circuit for proper operation would be time consuming. By placing the entire tank circuit in the nesting station, the components of the system are readily interchangeable and cabling lengths are not a factor in the proper operation.
In operation, the interrogator drives the tuned tank circuit comprised of series connected elements 302 and 304 with a square wave power signal. In an exemplary embodiment, the drive signal operates at 125 kHz, capacitor 302 is 3000 picoFarads and antenna coil 18 , 202 , or 304 is 800 microHenrys. The square wave drive signal is smoothed to a nearly sine wave signal which is emitted from the antenna coil 304 to excite RFID tag 19 . The excited tag emits a signal containing information unique to the tag (such as a serial number). This signal from the tag is detected by antenna coil 304 , rectified by diode 306 and sent to the interrogator for demodulation. The diode 306 generates a rectified peak voltage of the tank circuit 300 and the detected signal appears as a pulse stream in the form of a series of dips in the 125 kHz rectified carrier signal. This pulse stream is then decoded by the interrogator for the data it carries.
Interrogator Description
An embodiment 400 of an interrogator is shown in FIG. 7 which includes a processor 405 and an antenna reader circuit 404 . Antennas are connectable to the interrogator 400 at connection point 406 , and connection to the power supply and host or control module is effected at point 408 . Power for operating the interrogator 400 may be obtained locally or it may be received through the host communication cable. Communication of processor 405 with host or control module 102 is accomplished through port 410 . Host protocol interface port 410 may be a serial communication RS-232 port, or a differential port such as a multi-drop IEEE 485 or non multi-drop IEEE 422. The host or control module processes instructions according to a predefined operational structure, issuing commands to the interrogator for control of multiplexor 412 which selects the antenna which is to be driven at any given time.
In the exemplary embodiment shown in FIG. 7 , each antenna connected to the interrogator 400 has a dedicated power driver 411 circuit to generate the square wave excitation signal. The preferred power driver for the antennas is a low cost CMOS power driver to drive the square wave which is converted to a sine wave by the tuned circuit. In this example, each antenna has its own power driver within the interrogator because an electronic multiplexor switch with a low on resistance would be more expensive than the CMOS drivers. It is desirable to use power drivers with fast rise times, such as MOSFET and CMOS power drivers.
Details of the power driver circuitry are shown in FIG. 7 a . Drivers 411 have a fast rise time and radiate a high frequency harmonic because of that. To slow the rise time, drivers 411 are each connected to the antenna drive voltage through an inductor 413 . Further, an inductor 415 is electrically interposed between each driver 411 and ground. The inductors 413 and 415 are used to slow the rises and fall times of the driver 411 to reduce harmonic radiated RF.
Once the sensing antennas have excited a tag, the information received from tank circuit such as circuit 300 is sent to interrogator 400 and detected by detector 414 along a sense line 419 . Since only one antenna is excited at a time, all detector sense lines 419 from all nesting stations may be wired to the same detector. Processor or microchip controller 405 decodes data from the detector circuit 414 and can provide for sequential, ordered, or random scanning of the ports of the system through antenna selector 412 .
Detector circuit 414 is preferably implemented with analog amplification/detection of the DC rectified signal of the diode of the tuned circuit. The detected signal can be provided to processor 405 where each detection circuit 414 also has decoding capabilities, such as digital signal processing (DSP) type decoding built in. Each multiplexor board could have its own detector and processor, allowing for the driving of multiple antennas at once.
The processor 405 of interrogator 400 can be essentially a microcomputer, that is an all in one chip with on board RAM, EPROM, I/O points, a microprocessor, and analog input. The processor 405 could have hard-coded (burned into PROM) control software, or it could download the control software from a separate processor or computer system.
The interrogator 400 is preferably positioned in close proximity to the sensing antenna, which reduces the bundle of wires that must be run from the interrogator to the host computer or control module. From the interrogator, a low cost serial port may be used to run power into the interrogator along a communication line from the host. This allows for a wide operating voltage, which is preferably maintained low (24V for example) for safety purposes, but high enough that there is a low current draw. In this exemplary implementation, there is only one cable which needs to be disconnected in the event that the interrogator must be moved. In some environments, this a fairly common event. Referring back to FIG. 2 , a single interrogator may be located on the shelving units and serving all nesting stations of this shelf unit. If the shelf is to be moved, only one cable need be disconnected from the host. That cable may be a wall jack with in-the-wall network wires running to the host.
To keep the efficiency of the system up and power current down, voltage regulation circuitry 416 is used to perform regulation of unregulated 24V power to regulated 12V and 5V power. In one embodiment, DC to DC voltage regulators are used to perform main power reduction from an unregulated 24V power supply to a regulated 12V and 5V power supply to drive the interrogator components.
Alternatively, communications coming through host protocol interface 410 could be jumpered to an auxiliary processor board 418 that may contain an auxiliary processor 402 and wide variety of optional communication or I/O protocols 421 , such as ETHERNET, wireless modem, another processor with a large amount of memory, or the like. In such a configuration, the entire interrogator system 400 runs without interaction between the interrogator and the host. Gathered information may be downloaded to the host or control module at a later time. If no auxiliary processor 402 is present, then the connections which would go to the COM and COM1 ports of the auxiliary processor 402 are jumpered together.
A wide variety of auxiliary functions could also be performed by such an auxiliary control I/O 421 piggybacked to the circuit 404 . A daughterboard 418 with auxiliary input/output capability could be used to unlock doors, generate alarm signals, including local alarm signals for an object removed from a nesting station or boat, or the location from which an object has been removed, or drive an operator interface display terminal.
An interrogator system embodiment 500 of the present invention as shown in FIG. 8 comprises tags 502 and an interrogator 504 . Each tag 502 is associated with a specific lot, and contains identification information specific to the lot or item to which the tag is attached. Each tag 502 may be attached to a lot box or the like. Each tag, when excited, will communicate a signal indicative of its identification information. The tag can carry such information as a serial number and the like, which may be cross-referenced in a database maintained at the system host (computer). Antennas 506 are positioned in close proximity to the lot location which they will be polling. Interrogator 504 is connected to antennas 506 by a communication line 508 , which in the example shown will be a four line conductor. Connection jacks 510 and 512 connect the communication line 508 to the interrogator 504 and the nesting station 514 respectively. As discussed above, a four line conductor will typically be terminated with an RJ-11 four conductor jack.
Tags 502 , as has been mentioned above, are typically passive tags. This reduces the overall tag cost, which is important since a large number of tags may be required in application. The passive tags 502 , which allow for low cost, generally have a short effective operating range. The range may be on the order of 0 to 15-20 inches, depending upon antenna size. The larger the antenna, the greater the operating range. In one embodiment, the present invention limits the tag range further, preferably on the order of two (2) inches. Taking advantage of this short range allows this embodiment of the present invention to excite a tag and obtain its information, while also determining its exact location. Further, with simple timing and recordation schemes, it is possible given the precise nature of multiple antenna locations and close discrimination between lots to know which part is at which exact location at any given time.
Each interrogator has an address stored in interrogator address module 417 , which may be a volatile or a non-volatile memory. Each antenna connection has a sub-address.
Each antenna array location has its own unique identification information or address. In this way, the unique address can be programmed into the system, so that the physical location is not determined by where the antenna array is plugged in, but by what the address of the array has been programmed to. Then, under that address each antenna point will have its own address, allowing resolution down to each specific individual shelf and position. The system resolves exactly where each item is. This allows the mapping of a shelf and/or a location for a graphics display or the like, to locate an item with specificity. The reduced range of the antennas of this embodiment of the present invention allow for such a close up representation of exact item position. The range of on the order of two inches allows the reading of each tag to a precise location.
For example, in a wafer production fabrication, there may be 1000 lot boxes running production wafers, and 1000 lots of test wafers, plus 500 lots of reference type wafers, all at a general location. This results in 2500 lot boxes in a physical space. This can represent upwards of 5000 locations, because of the open queue space which is needed to move lots through such an operation. A system which works must be low cost and distributed to allow for multiple read locations, and inexpensive read points.
With a large number of locations to be polled, multiple interrogators will be required. Each interrogator concentrates multiple antenna locations into one interrogator. Typically in a wafer production line, production shelves are 2×4, or eight lots per shelf. Racks of shelves may be stacked six shelves high, and may have 32-56 boats per rack. Typically, the maximum number of boats per rack is 60. With two telephone cable per shelf, a single location may have 12 eight conductor flat cables running from the location to the interrogator. The benefits of local interrogators multiply with increased numbers of read locations.
With an interrogator having 60 antennas, 60 sets of data are collected and stored internally. At the next polling, only absolute differences are considered. That is, the delta data is polled. If only one of the sets of data has changed, it is the only set of data transmitted. This reduces the amount of data required to be transmitted. A complete polling may be taken at a specified interval or number of scans, in one embodiment every 100 scans. Further, tag information transmitted may be limited in one embodiment. Some tags contain an amount of user specific information that is the same for every tag associated with that user. If all tags polled are for a certain customer or user, then certain identification information need not be transmitted. Also, tags out of range of a certain specified parameter can be flagged, or an alarm can be given.
With 180 interrogators in a room, multiple options are available. First, all interrogators could be local, taking gathered information from its read locations or bays and sending the information into a switched multidrop configuration. This configuration would result in some data throughput difficulties (long time between individual location interrogation), but in a slow changing environment this may not be critical. Problems with such a multidrop configuration is that it places more equipment in the field, creating more service locations and an increased number of locations for things to break down. In one embodiment, communication drops to each interrogator are all sent back to a communications room in a star configuration which is in turn connected to the host. However, the scale could be dropped down to individual or a small number of components together on a power supply depending on the facility requirements.
Alternatively, an infrared link may be positioned on an interrogator, or located remote to an interrogator, and an infrared transceiver pod could be positioned on the ceiling of a room, for obtaining by infrared the location information gathered by each interrogator. Power would still need to be provided to each interrogator, most likely on a cable, but full data communication links to the host would not be required. Other technologies could also be supported, such as cellular phone, pager, wireless modem, solar power, and the like.
FIG. 9 shows an embodiment 600 of another system embodying the present invention. Multiplexor 606 has a plurality of connections to single antennas 608 a , 608 b , . . . 608 n , which are driven by drivers 610 a , 610 b , . . . 610 n . A common detector circuit 602 is connected in parallel to each of the drivers 610 a , 610 b , . . . 610 n and to controller 604 . Controller 604 controls selection of which antenna 608 is to be active at any given time.
In embodiments of the invention as described above, the use of a flat coil antenna has been shown to allow some lateral movement of the boxes to allow for positioning tolerances without significant degradation of performance. Further, the flat coil antenna construction also provides relatively good height detection of the antenna without drastically affecting the performance of the system. A flat coil is more sensitive to ferrous materials in the vicinity of the coil. However, if the shelf or nesting station upon which tags are placed is composed of a material such as wood, plastic, and the like instead of metal, then a balance between separation of the antenna from the shelf and the performance of the antenna is not an issue.
If the height or distance of the antenna from the tag increases, the communication or readability degrades. As the height or distance decreases, the tuned circuit becomes detuned. Further, if a ferrous material object such as a wrench, clipboard, or pad is placed on or in close proximity to the nesting station or antenna, a voltage anomaly due to the object may show up in the output from the diode of the tuned circuit, and tag communication may degrade. At that point, it will be evident that the antenna is not sensing a tag, but instead is sensing something abnormal. For example, if no voltage is indicated in the tuned circuit, that could indicate that the antenna is not present, or that there is a fault in the circuit.
Changes in antenna performance or surrounding load will change the peak rectified voltage from the diode. This changed peak rectified voltage can be compared to historical data or absolute values to detect system faults or performance degradation.
An embodiment 700 of an antenna which decreases sensitivity to anomalies is shown in FIG. 10 . A ferrous cover plate or metal sheet 702 is positioned a predetermined distance 706 from the back of the antenna 704 . The metal sheet or cover 702 serves to magnetically preload the coil 704 . This ferric loading of the coil serves to reduce the sensitivity of the antenna 704 to further surrounding metal. The tuned circuit, such as tuned circuit 300 , is then tuned with the cover or metal sheet 702 in place. It has been determined that a preferable separation 706 between the antenna 704 and the plate or sheet 702 is approximately ⅜ of an inch. However, other distances will also serve to preload the tuned circuit.
Process Flow
A method embodiment 800 of tracking the location of identification tags as shown in FIG. 11 comprises activating a sensing antenna, which is part of a tuned circuit, to excite a passive identification tag in block 802 , determining if a voltage is induced in the sensing antenna in block 804 , and storing or communicating to the host any induced voltage in the sensing antenna in block 808 if a voltage is induced in the sensing antenna.
An interrogator such as interrogator 400 described in detail above with included multiplexing capability controls multiple antennas all attached to the interrogator, with one antenna being driven at any given time. A detector circuit in the interrogator serves to detect the signals returned from the sensing antenna. The method 800 may further comprise activating a plurality of further sensing antennas in a predetermined or random sequence in block 810 , followed by the re-execution of blocks 804 and 808 as needed.
The sensing antennas and interrogators described in detail above may be used in a tag identification method such as method 800 . One or more processors in the interrogator may be used to not only decode data coming back from the detector circuit but also to provide sequential scanning of the ports. Process flow in method 800 allows for either scanning all antenna locations or ports regardless of whether anything is plugged into them. In other words, the sensing antenna, tuned circuit, and detector circuit determine whether an antenna is plugged into a location or not by measuring the voltage generated by the rectification of the tank circuit. This voltage is typically a nominal voltage stable across all antennas.
If no voltage is present in decision block 804 , several options for further process flow are available, and will be described in detail below. If no voltage is present, that may indicate that no antenna is present. Alternatively, a lookup table or representation of the configuration of the antenna system may indicate that there should be an antenna at a given location. Further, when a tag powers up, it may not correctly initialize or communicate information. A reinitialization may be necessary. If no voltage is present in block 804 , an alarm for an antenna failure or other alarm condition, such as antenna degradation or the like, can be generated. The host system can track antenna voltage and compare historical data to detect problems as discussed above.
A self-testing embodiment of a material tracking system is a part of the present invention. A self-testing embodiment 1000 is shown in detail in FIG. 12 . Self-testing embodiment 1000 incorporates some of the basic process flow of embodiment 800 . Embodiment 1000 comprises selecting a scan method from a number of possible scanning methods in block 1002 , checking an antenna map or the like to allow skipping of inactive antennas in block 1004 , and activating the selected antenna in block 802 . If no antenna is supposed to be present, process flow can continue with the next antenna position. If the antenna voltage for the selected antenna does not exceed a predetermined lower limit as determined by decision block 1005 , the host is alerted or a local alarm is activated in block 1020 . If the antenna voltage for the selected antenna is above the predetermined lower limit as determined by decision block 1005 , process flow continues with block 1006 .
In block 1006 , a timeout timer is reset. The timeout timer counts a predetermined time during which the embodiment 1000 waits for tag data to be read. The embodiment waits for tag data or the timeout limit of the timeout timer in block 1008 . A determination is made as to whether tag data has been detected in decision block 1010 . If tag data has been detected in block 1010 , the data is stored or sent to the host in block 808 , and the next antenna is selected in block 810 . Following that, process flow continues with block 1004 .
For each instance in which tag data is not detected, an iteration count is compared against an iteration limit in block 1012 . A predetermined limit of the number of iterations allowed for detecting tag data is set in the embodiment 1000 . This number may be set to depend on a number of factors, including the response time of the tags, the required or desired response time of the circuit, and the like. Each unsuccessful detection of tag data results in an incrementing of the iteration count. If no tag data has been detected in block 1010 , the iteration count is checked against a predetermined iteration limit in decision block 1012 . If the iteration count is not above the predetermined limit, the iteration counter is incremented in block 1016 , and the antenna driver is cycled off and back on in block 1018 . Process flow continues with decision block 1005 . If the iteration count is above the predetermined iteration limit, then “no tag” data is generated in block 1014 , and process flow continues with block 808 . At the selection of the next antenna, the iteration count is reset.
Typically, a time period of approximately 50 milliseconds is enough to determine whether a signal will be present. This amounts to approximately two power cycles. If no tag is sensed, the typical scan time is approximately 0.1 seconds for each scan. In a worst case scenario, an entire shelf of 60 antennas with no tags can be scanned in approximately six (6) seconds. The fastest read conditions occur when all active antennas have tags present, and all tags properly power up.
Depending upon required response time, the ratio of read points to interrogators could be increased. At 60 to 1, scan time for a shelf is approximately 6 seconds. Increasing the read point to interrogator ratio to 500 to 1 or higher would push scan time to around a minute, which is still acceptable for numerous inventory functions.
Given the availability of polling a shelf of up to 60 positions in approximately six seconds, any number of possibilities of tracking procedures and other inventory control functions may be implemented in computer software. Currently, bar codes on lots are scanned with the information therefrom being stored in a database. The identification tags are generally molded into a wafer boat or box. Typically, the wafer box remains with the lot for most of the lot life except for a few times, for example, when the boxes are washed, or if the box gets contaminated.
Another embodiment 1100 of the present invention for tracking the carrier box association to a lot is shown in FIG. 13 . A lot is placed with a box in block 1102 , and a bar code label is placed on the box in block 1104 . The box is associated with the tag in block 1106 . A database entry is made regarding the association in block 1108 . This same database is used to record the sampling information generated at various polling locations around the plant or location in which a system embodiment of the present invention is in place.
Yet another embodiment 1110 of the present invention for associating a tag with material and manufacturer information is shown in FIG. 13 a . Method 1110 comprises scanning, collecting, or entering manufacturer data into a database in block 1112 , attaching a tag to the raw material in block 1114 , and associating the tag with the manufacturer data in block 1116 . The material is moved to storage in block 1118 , transported in block 1120 , and is moved through a production line in block 1122 . While in any phase of the process 1110 , apparatus embodiments of the present invention may be used to track the location of the material. The material is transported again in block 1124 , and again stored in block 1126 . At the completion of the production cycle, the tag is removed in block 1128 , and is disposed of or returned for reprogramming in block 1130 .
An identification tag may be attached to an object to be tracked by method embodiment 1150 shown in FIG. 14 . Method 1150 comprises forming a shallow polypropylene cup in block 1152 , placing the identification tag in the polypropylene cup in block 1154 , welding the identification tag to the polypropylene cup ultrasonically in block 1156 , and welding the polypropylene cup to the object ultrasonically in block 1158 .
The database generated from all of the association information of the tags and boxes in a particular database can be sampled to generate history information. It is envisioned that such a database will be accessible at multiple locations around a plant or inventory location. The database can be queried to generate the appropriate information. The possibilities are numerous given the present invention embodiments' ability to update information of a box approximately every 6 seconds. Information that could be tracked includes by way of example only, and not by way of limitation, timing a process, timing a transfer time from one location to another, tracking missing lots, tracking movement of lots, detecting when a tag is missing, and the like.
Further, the information in the database may be queried, and software written for managing product flow in a production area, scheduling, tracking, notification of arrival and departure, history, spare equipment inventory, and the like. The nearly real-time gathering of information allows vast flexibility limited only by the capabilities of the systems on which the software may be implemented.
The methods shown in FIGS. 11 , 12 , and 13 may be implemented in various embodiments in a machine readable medium comprising machine readable instructions for causing a computer 1200 such as is shown in FIG. 15 to perform the methods. The computer programs run on the central processing unit 1202 out of main memory, and may be transferred to main memory from permanent storage via disk drive 1204 when stored on removable media or via a network connection or modem connection when stored outside of the personal computer, or via other types of computer or machine readable medium from which it can be read and utilized.
Such machine readable medium may include software modules and computer programs. The computer programs comprise multiple modules or objects to perform the methods in FIGS. 11 , 12 , and 13 , or the functions of various modules in the apparatuses of FIGS. 3 , 7 , 8 , and 9 . The type of computer programming languages used to write the code may vary between procedural code type languages to object oriented languages. The files or objects need not have a one to one correspondence to the modules or method steps described depending on the desires of the programmer. Further, the method and apparatus may comprise combinations of software, hardware and firmware.
The software implementing the various embodiments of the present invention may be implemented by computer programs of machine-executable instructions written in any number of suitable languages and stored on machine or computer readable media such as disk, diskette, RAM, ROM, EPROM, EEPROM, or other device commonly included in a personal computer. Firmware can be downloaded by the host into the microcontroller or the auxiliary processor for implementing the embodiments of the invention.
Annunciator Design
Given a typical scan time for a shelf of approximately six seconds, a feedback mechanism such as an annunciator, bell, whistle, light, or the like could be used in a circuit such as circuit 150 shown in FIG. 4 , that could be used to locate a lot or a specific part in a lot location. A representation such as a graphical representation of a shelf, could be employed at a visual display terminal, with the exact location of a certain identified part to be shown on the display, Such representation, due to the close detail allowed by the present invention, would facilitate pinpointing the location of an item or lot for easy retrieval of the part or item.
A coordinate mapping system could be used with graphics on a computer screen, including a number for elevation of a particular shelf in a stack, and a standard position for the shelf, for example an XY scheme with shelf number and position.
An annunciator embodiment 1300 of the present invention is shown in FIG. 16 . A variety of different annunciator type configurations are shown in FIG. 16 . For example, one annunciator embodiment 1302 comprises a resistor 1303 and a light emitting diode 1304 connected in series across the incoming square wave signal. The annunciator embodiment 1302 will light the LED 1304 when the shelf or lot location to which the annunciator embodiment 1302 is connected is polled.
Another annunciator embodiment 1308 comprises a tuned circuit connected across an incoming square wave, the tuned circuit having a different resonance frequency than the resonance frequency of the tuned circuit used as a sensing antenna. Annunciator embodiment 1308 comprises a tuned LC circuit 1310 and an indicator 1312 . Indicator 1312 will become activated when the shelf or lot location to which the annunciator embodiment 1308 is connected is polled with the alternate frequency.
In another annunciator embodiment 1316 , a signaling LED 1318 is shown in reverse polarity. In normal operation, suppose that ground is connected to positive, and a bipolar driver sends a drive signal to an antenna. Switching the drive circuit or the ground polarity allows a pulsing reverse bias causing LED 1318 to light. In normal connections, with a positive bias on LED 1318 , it is not lit. Placing a reverse bias on the annunciator embodiment 1316 causes LED 1318 to light.
In another embodiment, an alphanumeric display 1320 is operatively connected across an incoming square wave. The display 1320 can derive power from the line, or power can be externally provided. When the line is not used for driving an antenna, the display 1320 is recognized by the system, and the display may be used to display tag information such as the tag number, lot number, and the like. Once the tag information is decoded, the path to the host of the microcontroller could shut off the antenna, and an ASCII signal could be sent on a non-LC frequency. The display recognizes valid data and displays the data.
Primary application of the embodiments of the present invention are seen in wafer applications. However, multiplexing antennas offers a wide variety of other potential applications such as in large parking lots where RFID tags are placed at front or rear bumpers of vehicles, for example, and antennas are placed at the end of the parking space for identification of location and identity of vehicles. Other uses for the present invention include inventory control systems with large numbers of points to be inventoried but not requiring immediate scanning. Another example is material on a conveyer belt for objects that are momentarily stationary or stationary within approximately a ten second or longer period. Such modifications, variations, and other uses will be apparent to one of skill in the art, and are within the scope of the present invention.
For example, another embodiment of an application 1700 for the present invention is shown in FIG. 17 . Tracking of raw material such as gas bottles, chemical bottles such as gas container 1702 is accomplished using an omnidirectional tag 1704 situated around the neck of a canister 1702 contained in a cabinet or other enclosure 1706 . An antenna 1708 connected to a system such as those discussed above receives information from collar or tag 1704 upon polling of the tag location. An auxiliary I/O control such as control 421 is used to actuate a valve 1710 to dispense gas from the container 1702 . The auxiliary control controls the gas flow, rate of dispensation, and the like.
Manufacture of the Nesting Stations
Physical implementation of the nesting stations may vary. One implementation is to use a clamshell-type plastic molding with molded ridges, stiffeners and anchor points molded directly into the plastic. The circuit board for the tuned tank includes the capacitors with the connection jacks mounted directly on the circuit board. The circuit board lays in a notch in the top half of the assembly. The metal ground plane plate is placed in the bottom half of the assembly. The antenna coil leads are attached to the circuit board while the antenna coil would be attached to the top half of the molding. A foam filler fills then fills the void and the molding is closed. The assembly of this type is key to keeping the cost low. The configurations allowed by this type of assembly cover very diverse arrangements.
CONCLUSION
The embodiments of the present invention have added multiplexing circuitry to an interrogator, allowing a single detection circuit and processor to be common to a plurality of antennas. A control module or host is used to control the driving of the antennas.
The embodiments of the present invention take advantage of a short range of a sensing antenna to distinguish multiple lots which may be placed very close together in a small area. One interrogator can distinguish many items. The invention has a low cost per read station, which is beneficial due to the large number of read locations.
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A method and apparatus for tracking items automatically is described. A passive RFID (Radio Frequency IDentification) tag is used with a material tracking system capable of real-time pinpoint location and identification of thousands of items in production and storage areas. Passive RFID tags are attached to the item to be tracked, remote sensing antennas are placed at each remote location to be monitored, interrogators with several antenna inputs are connected to the sensing antennas to multiplex the antenna signals, and a host computer communicates with the interrogators to determine item locations to an exacting measure.
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